JP5563867B2 - Multi-cylinder internal combustion engine with cylinder deactivation mechanism - Google Patents

Description

  The present invention relates to a multi-cylinder internal combustion engine having a cylinder deactivation mechanism.

  2. Description of the Related Art Conventionally, a multi-cylinder internal combustion engine having a cylinder deactivation mechanism is known that controls an intake valve and an exhaust valve of an internal combustion engine by driving the valve deactivation mechanism with hydraulic pressure (see, for example, Patent Document 1).

JP-A-9-256879

By the way, in the multi-cylinder internal combustion engine provided with the conventional cylinder deactivation mechanism, when the internal combustion engine is rotating at a low speed at a low load as in idling, fuel consumption is achieved by deactivating some cylinders. It was supposed to improve fuel economy by suppressing.
By the way, during the cylinder deactivation period, the intake valve and the exhaust valve are maintained in the closed state, so that a period during which the combustion chamber becomes negative pressure occurs. Therefore, when the cylinder deactivation period becomes longer, oil enters the combustion chamber. The so-called rising oil may cause the lubricating oil to enter the combustion chamber, and the invading lubricating oil may adhere to the spark plug and cause the smoldering of the spark plug.
Therefore, an object of the present invention is to provide a multi-cylinder internal combustion engine having a cylinder deactivation mechanism that can suppress smoldering of an ignition plug in a deactivated cylinder in a multi-cylinder internal combustion engine having a cylinder deactivation mechanism. .

To achieve the above object, the present invention provides a multi-cylinder internal combustion engine (10) including a cylinder deactivation mechanism (80) that deactivates a cylinder by maintaining an intake valve (11) and an exhaust valve (12) in a closed state. Before starting the transition from the operating state in which the intake valve (11) and the exhaust valve (12) are opened to the closed rest state, the fuel injection of the cylinder to be stopped is stopped, and the ignition plug of the cylinder to be stopped Stop the energization of the gas, and open the intake valve (11) and perform an air cycle in which the gas in the combustion chamber (20-2, 20-3) is exchanged, and an instruction to stop the fuel injection is issued. The fuel injection is stopped after the fuel is injected in the intake stroke of the four-cycle period immediately before the period corresponding to the air cycle and before the intake stroke in the period corresponding to the air cycle. Is a cylinder deactivation performed after the fuel injection timing at which the last burned fuel is injected, at least before the intake stroke of one cycle before the four-cycle period for shifting to cylinder deactivation. And before the intake valve (11) and the exhaust valve (12) complete the transition from the rest state to the operation state, the fuel injection and ignition of the spark plug are not performed, and the intake valve (11) and the carrying to the operation start both of the exhaust valve (12), and said cylinder operation after the cylinder deactivation to start running exhaust valve (12) above, which can be variable cylinder changes the number稼dynamic cylinders A mode is selected, and in a state where some cylinders are deactivated, the cylinder deactivation is stopped at the time of low load and low rotation, and all cylinders (C1 to C4) are set as operating cylinders.
According to the above configuration, when the multi-cylinder internal combustion engine is rotating at low load and low speed, cylinder deactivation is stopped and all cylinders are operating cylinders. Therefore, the deactivation period of the cylinder can be effectively shortened, and the intake valve (11) and the exhaust By maintaining the valve (12) in the closed state, oil easily accumulates in the combustion chamber (inside the cylinder), so that the soaking up of lubricating oil due to so-called oil rise is prevented from entering the combustion chamber and adheres to the spark plug. It is possible to prevent smoldering of the spark plug of the cylinder that has been stopped due to the lubricating oil.
In addition, since the intake valve (11) and the exhaust valve (12) are maintained in the closed state, a pumping loss that occurs when the valves are opened and closed without maintaining the valves in the closed state does not occur.
In addition, since the gas in the combustion chamber is replaced when shifting to cylinder deactivation, it is possible to scavenge the fuel adhering to the spark plug or remaining in the combustion chamber and the fuel adhering to the intake port. Even in such a case, it is possible to improve the combustion efficiency and prevent the smoldering of the ignition plug of the cylinder that has been stopped, so that the operation (operation) can be resumed at an appropriate air-fuel ratio.
In addition, since energization is not performed by the ignition plug of the deactivated cylinder during the cylinder deactivation period, it is possible to prevent the lubricating oil adhering to the ignition plug from smoldering during discharge during the deactivation period.

The present invention is also directed to a multi-cylinder internal combustion engine having a cylinder deactivation mechanism (80) that deactivates a cylinder by maintaining the intake valve (11) and the exhaust valve (12) in a closed state. 110), and before starting the transition from the operating state in which the intake valve (11) and the exhaust valve (12) are open to the closed inactive state, Stopping energization of the ignition plug of the cylinder to be stopped, and an air cycle for performing gas exchange for opening the intake valve (11) and replacing the gas in the combustion chamber (20-2, 20-3). The fuel injection stop instruction is after the fuel is injected in the intake stroke of the 4-cycle period immediately before the period corresponding to the air cycle, and before the intake stroke in the period corresponding to the air cycle. The fuel injection is performed, and the start of the stop of the fuel injection is before the intake stroke of at least one cycle before the cycle of the four cycles for shifting to the cylinder deactivation and the fuel burned last is injected The cylinder is deactivated after the timing, and the fuel injection and ignition of the spark plug are performed before the intake valve (11) and the exhaust valve (12) complete the transition from the deactivated state to the activated state. do not us, when to run start both the intake valve (11) and said exhaust valve (12), and said cylinder operation after the cylinder deactivation to start running exhaust valve (12) above,稼dynamic When the variable cylinder mode in which the number of cylinders can be changed is selected and some of the cylinders are inactive, and the vehicle speed is equal to or lower than a predetermined value, the cylinder inactive is stopped and all cylinders (C1 Characterized in that the operating cylinders to C4).
According to the above configuration, when the vehicle speed is equal to or lower than the predetermined value, the cylinder deactivation is stopped and all cylinders are set as operating cylinders. Therefore, the cylinder deactivation period when the vehicle speed is equal to or lower than the predetermined value can be effectively shortened. By keeping the intake valve (11) and the exhaust valve (12) in the closed state, the oil easily accumulates in the combustion chamber (inside the cylinder), so that the penetration of the lubricating oil into the combustion chamber due to so-called oil rise is suppressed. Thus, it is possible to prevent smoldering due to lubricating oil adhering to the ignition plug of the cylinder that has been stopped.
In addition, since the intake valve (11) and the exhaust valve (12) are maintained in the closed state, a pumping loss that occurs when the valves are opened and closed without maintaining the valves in the closed state does not occur.
In addition, since the gas in the combustion chamber is replaced when shifting to cylinder deactivation, it is possible to scavenge the fuel adhering to the spark plug or remaining in the combustion chamber and the fuel adhering to the intake port. Even in such a case, it is possible to improve the combustion efficiency and prevent the smoldering of the ignition plug of the cylinder that has been stopped, so that the operation (operation) can be resumed at an appropriate air-fuel ratio.
In addition, since energization is not performed by the ignition plug of the deactivated cylinder during the cylinder deactivation period, it is possible to prevent the lubricating oil adhering to the ignition plug from smoldering during discharge during the deactivation period.

In this case, the predetermined value for setting all cylinders as operating cylinders may be set higher as the output of the multi-cylinder internal combustion engine increases.
According to the above configuration, the cylinder idle period can be shortened in accordance with the vehicle speed, so that the soaking of the lubricating oil due to so-called oil rise can be suppressed without being affected by the vehicle speed, and the lubricating oil adhered to the spark plug can be used. The smoldering of the spark plug of the idle cylinder can be prevented.

In addition, operation may be performed with all cylinders as active cylinders during low load and low rotation, and operation may be performed with some cylinders deactivated after a predetermined period of time has elapsed since the start of cylinder operation.
According to the above configuration, it is possible to improve fuel efficiency while preventing smoldering of the spark plug of the idle cylinder.

According to the present invention, the idle time of the cylinder can be effectively shortened, so that the soaking of the lubricating oil due to the so-called oil rise is suppressed, and the smoldering caused by the lubricating oil adhering to the ignition plug of the idle cylinder is reduced. Can be prevented.
In addition, when the speed of a vehicle equipped with a multi-cylinder internal combustion engine is below a predetermined value, the cylinder idle period can be effectively shortened, so that the soaking of the lubricating oil due to so-called oil rising is prevented from entering the combustion chamber. The smoldering of the spark plug of the idle cylinder due to the lubricating oil adhering to the cylinder can be prevented.
In addition, fuel consumption can be improved while preventing smoldering of the spark plug of the idle cylinder.
Further, in the cylinder immediately after the cylinder operation, the combustion efficiency can be improved and the smoldering of the spark plug of the idle cylinder can be prevented.
In addition, it is possible to prevent the lubricating oil adhering to the spark plug from smoldering due to discharge during the cylinder deactivation period.

1 is a left side view showing a motorcycle including an internal combustion engine according to an embodiment of the present invention. It is sectional drawing which shows an internal combustion engine. It is a mimetic diagram showing the composition at the time of seeing an internal combustion engine from the upper part. It is an expanded sectional view of the valve deactivation mechanism on the intake side. It is a general | schematic block diagram of a control system. It is explanatory drawing of the fundamental operation | movement at the time of cylinder deactivation. It is a processing flowchart of cylinder deactivation / operation control. It is a processing timing chart of more specific cylinder deactivation / operation control. It is a process flowchart in case all the cylinders are made into an active cylinder at the time of low load and low engine speed. It is a processing flowchart in the case of changing all the cylinders to be operating cylinders at low load and low engine speed and changing the cylinders to be deactivated at any time. It is a state transition diagram of a cylinder operation mode. It is explanatory drawing of the engine operating state corresponding to an output and a vehicle speed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a left side view showing a motorcycle including an internal combustion engine according to an embodiment of the present invention. In the following description, descriptions of directions such as front and rear, left and right and up and down are for the vehicle body.
A body frame 111 of the motorcycle 110 includes a head pipe 112 positioned at the front of the vehicle body, a pair of left and right main frames 114 extending rearward from the head pipe 112 to the center of the vehicle body, and extending downward from a rear end portion of the main frame 114. A pair of left and right pivot plates 115 and a rear frame (not shown) extending from the rear end of the main frame 114 to the rear of the vehicle body are provided.
A front fork 116 is rotatably attached to the head pipe 112, and a front wheel 117 is rotatably supported at the lower end of the front fork 116. A steering handle 118 is attached to the upper portion of the head pipe 112.

Below the main frame 114, a front / rear V-type four-cylinder internal combustion engine 1 is arranged. The internal combustion engine 1 is a horizontally-placed engine in which the crankshaft 2 is oriented horizontally in the horizontal direction, is an OHC type four-stroke water-cooled type, and includes a crankcase 3. This is a narrow-angle V-type engine in which the front bank Bf and the rear bank Br that are inclined to V are configured in a V shape, and the bank angle of each other is smaller than 90 degrees.
One end of a pair of left and right exhaust pipes 119 is connected to the exhaust port of the front bank Bf. The exhaust pipe 119 extends downward from the exhaust port and is then routed toward the rear of the vehicle body, so that the rear bank Br The exhaust pipes 120 are connected to a pair of left and right exhaust pipes 120 extending from the exhaust port, and are connected to a muffler (not shown) provided behind the internal combustion engine 1 via a single exhaust pipe 127 (see FIG. 3). Yes.

A pivot shaft 121 is provided behind the internal combustion engine 1, and a rear fork 122 is attached to the pivot shaft 121 so as to be swingable in the vertical direction about the pivot shaft 121. A rear wheel 131 is rotatably supported at the rear end portion of the rear fork 122. The rear wheel 131 and the internal combustion engine 1 are connected by a drive shaft 123 provided in the rear fork 122, and rotational power from the internal combustion engine 1 is transmitted to the rear wheel 131 through the drive shaft 123. A rear cushion 124 that absorbs an impact from the rear fork 122 is suspended between the rear fork 122 and the vehicle body frame 111.
A stand 125 for stopping the vehicle body is provided at the rear part of the internal combustion engine 1. A side stand 126 is provided at the lower part of the left side surface of the internal combustion engine 1.

A fuel tank 141 is mounted on the upper part of the main frame 114 so as to cover the upper part of the internal combustion engine 1. A seat 142 is located behind the fuel tank 141, and the seat 142 is supported by the rear frame. A tail lamp 143 is disposed behind the seat 142, and a rear fender 144 is disposed below the tail lamp 143 so as to cover the rear wheel 131.
The motorcycle 110 has a resin body cover 150 that covers the vehicle body. The vehicle body cover 150 includes a front cover 151 that continuously covers from the front of the vehicle body frame 111 to the front portion of the internal combustion engine 1, and a seat. And a rear cover 152 that covers the lower portion of 142. A pair of left and right mirrors 153 are attached to the top of the front cover 151. Further, a front fender 146 is attached to the front fork 116 so as to cover the upper part of the front wheel 117.

FIG. 2 is a cross-sectional view showing the internal combustion engine 1. FIG. 3 is a schematic diagram showing a configuration when the internal combustion engine 1 is viewed from above. In FIG. 2, the upper and lower sides of the figure are described as the upper and lower sides of the internal combustion engine 1, the left side of the figure is the front side of the internal combustion engine 1, and the right side of the figure is the rear side of the internal combustion engine 1.
As shown in FIG. 2, a V bank space K, which is a space formed in a V shape in a side view, is formed between the front bank Bf and the rear bank Br.
The crankcase 3 is divided vertically and has an upper crankcase 3U and a lower crankcase 3L. The crankshaft 2 is rotatably supported so as to be sandwiched between the crankcases 3U and 3L. The upper crankcase 3U includes a front cylinder block 3f and a rear cylinder block 3r in which two cylinders are arranged on the left and right, respectively. It extends obliquely upward so as to form a V shape in a side view and is integrally formed.

Below the lower crankcase 3L, an oil pan 3G in which the oil of the internal combustion engine 1 is stored is provided so as to bulge downward. An oil pump 50 that circulates oil in the internal combustion engine 1 is located below the crankshaft 2 in the lower crankcase 3L.
In the crankcase 3, a main shaft 41, a counter shaft 42, and an output shaft 43 that are disposed in parallel with the crankshaft 2 are provided. These shafts 41, 42, and 43 including the crankshaft 2 constitute a gear transmission mechanism that transmits the rotation of the crankshaft 2 in the order of the main shaft 41, the counter shaft 42, and the output shaft 43. Between the counter shaft 42 and the main shaft 41, a six-speed transmission gear group is disposed so as to constitute a transmission. A drive shaft 123 (see FIG. 1) is connected to the output shaft 43 via a bevel gear (not shown).

  A front cylinder head 4f is superimposed on the front cylinder block 3f diagonally forward and fastened by fastening bolts (not shown), and a front cylinder head cover 5f covers the front cylinder head 4f. Similarly, a rear cylinder head 4r is superimposed on the rear cylinder block 3r obliquely rearward and fastened by fastening bolts (not shown), and the rear cylinder head 4r is covered by a rear cylinder head cover (not shown).

  A pair of cylinder bores 3a is formed in each of the front cylinder block 3f and the rear cylinder block 3r, and a piston 6 that reciprocates in the cylinder bore 3a is accommodated in each cylinder bore 3a. Each piston 6 is connected to one crankshaft 2 common to each piston 6 via connecting rods 7f and 7r.

  As shown in FIG. 3, the internal combustion engine 1 is provided with a first cylinder C1, a second cylinder C2, a third cylinder C3, and a fourth cylinder C4 in which the piston 6 is accommodated. Specifically, the left cylinder of the front bank Bf is the first cylinder C1, the right cylinder is the fourth cylinder C4, the left cylinder of the rear bank Br is the second cylinder C2, and the right cylinder is the third cylinder C3. It is.

As shown in FIGS. 2 and 3, the front cylinder head 4f and the rear cylinder head 4r are respectively provided with combustion chambers 20-1 to 20-4 positioned above the four cylinder bores 3a. The front cylinder head 4f includes an intake port 21f and an exhaust port 22f that communicate with the combustion chamber 20-1 of the first cylinder C1, and an intake port 21f and an exhaust port 22f that communicate with the combustion chamber 20-4 of the fourth cylinder C4. Is provided.
The rear cylinder head 4r includes an intake port 21r and an exhaust port 22r that communicate with the combustion chamber 20-2 of the second cylinder C2, and an intake port 21r and an exhaust port 22r that communicate with the combustion chamber 20-3 of the third cylinder C3. Is provided.
A front throttle body 60f for adjusting the amount of intake air flowing through the intake ports 21f, 21f is connected to the intake ports 21f, 21f of the front cylinder head 4f, and an intake air is connected to the intake ports 21r, 21r of the rear cylinder head 4r. A rear throttle body 60r for adjusting the amount of intake air flowing to the ports 21r and 21r is connected.

As shown in FIG. 2, a pair of intake valve openings 81 and a pair of exhaust valve openings 82 are formed in the combustion recess 20A that forms the upper surfaces of the combustion chambers 20-1 to 20-4 of each cylinder. The intake valve opening 81 is opened and closed by the intake valve 11 (valve), and the exhaust valve opening 82 is opened and closed by the exhaust valve 12 (valve).
The intake valve 11 includes a valve body portion 11b that closes the intake valve opening 81, and a valve stem 11c that extends from the valve body portion 11b as a base end. The exhaust valve 12 includes a valve body portion 12b that closes the exhaust valve opening 82, And a valve stem 12c extending from the valve body 12b as a base end.
The valve stem 11c and the valve stem 12c are slidably fitted to a guide cylinder 83 provided above the intake valve opening 81 and the exhaust valve opening 82.

Retainers 84 are provided at the valve stem ends 11d and 12d at the tips of the valve stem 11c and the valve stem 12c, respectively. The coiled valve spring 11a and the valve spring 12a are provided between each retainer 84 and the intake valve opening 81 and the exhaust valve opening 82, and bias the intake valve 11 and the exhaust valve 12 in the closing direction.
As shown in FIG. 2, the intake valve 11 and the exhaust valve 12 are opened and closed by a unicam type valve gear 10 driven by a camshaft 25 provided for each cylinder head 4f and 4r. Is done.

The valve gear 10 includes a camshaft 25 that is rotatably supported by a support portion above the intake valve 11 in each cylinder head 4f, 4r, and an axis parallel to the camshaft 25. It has a rocker shaft 26 fixed to 4r and a rocker arm 27 pivotally supported on the rocker shaft 26.
The camshaft 25 has an intake cam 30 and an exhaust cam 31 that protrude to the outer peripheral side of the camshaft 25, and is rotated in synchronization with the rotation of the crankshaft 2. The intake cam 30 and the exhaust cam 31 have a cam profile in which the distance (radius) from the center to the outer periphery is not constant, and the intake valve 11 and the exhaust valve are changed by the change in radius when the intake cam 30 and the exhaust cam 31 rotate. Move 12 up and down.

A valve lifter 13 is provided between the camshaft 25 and the intake valve 11 so as to be slidably fitted to the cylinder heads 4f and 4r below the camshaft 25.
One end of a rocker arm 27 that is pivotally supported by the rocker shaft 26 is provided with a roller 27a that is in rolling contact with the exhaust cam 31, and a tappet screw 27b that is in contact with the upper end of the exhaust valve 12 is screwed on the other end to adjust the advance / retreat position. Are combined. A valve lifter 13 is provided between the tappet screw 27 b on the rear bank Br side and the exhaust valve 12.

  When the intake cam 30 and the exhaust cam 31 are rotated integrally with the camshaft 25, the intake cam 30 pushes down the intake valve 11 through the valve lifter 13, and the exhaust cam 31 that contacts the roller 27a passes through the rocker arm 27. The exhaust valve 12 is pushed down, and the intake ports 21f and 22f and the exhaust ports 22r and 22r are opened and closed at a predetermined timing determined by the rotation phase of the intake cam 30 and the exhaust cam 31.

As shown in FIG. 3, the front throttle body 60f is provided at the rear portion of the front bank Bf, and a pair of intake passages 61-1 and 61-4 communicating with the first cylinder C1 and the fourth cylinder C4 are provided as one case body 62. It is configured to prepare for. The intake passage 61-1 is provided with a butterfly throttle valve 63-1 that can be opened and closed, and the intake passage 61-4 is provided with a butterfly throttle valve 63-4 that can be opened and closed.
The throttle valves 63-1 and 63-4 are supported by a shaft 64 provided in the intake passages 61-1 and 61-4. The shaft 64 is driven by one motor 65 connected to the shaft 64, and the two throttle valves 63-1 and 63-4 are driven simultaneously. That is, the throttle valves 63-1 and 63-4 are throttle valves common to the front bank Bf driven simultaneously by one motor 65.

  The rear throttle body 60r is provided in the front part of the rear bank Br, and includes a pair of intake passages 61-2 and 61-3 communicating with the second cylinder C2 and the third cylinder C3 in one case body 68. Configured. The intake passage 61-2 is provided with a butterfly throttle valve 63-2 that can be opened and closed, and the intake passage 61-3 is provided with a butterfly throttle valve 63-3 that can be opened and closed. The throttle valves 63-2 and 63-3 are supported by a shaft 64 provided in the intake passages 61-2 and 61-3. The shaft 64 is driven by one motor 65 connected to the shaft 64, and the two throttle valves 63-2 and 63-3 are driven simultaneously. That is, the throttle valves 63-2 and 63-3 are throttle valves common to the rear bank Br that are simultaneously driven by one motor 65.

The throttle valves 63-1 to 63-4 are so-called TBWs that open and close by electronic control in conjunction with the corresponding motors 65 according to the accelerator opening operated by the driver, that is, the driver's intention to accelerate. This is a (throttle-by-wire) type throttle valve. The driving state of each motor 65 is controlled according to the accelerator opening and the like by an ECU 76 as an electronic control unit of the vehicle.
In the present embodiment, the throttle valves 63-1 and 63-4 of the front bank Bf are driven by a common control by a single motor 65, and the throttle valves 63-2 and 63-3 of the rear bank Br are Since the four motors 65 are driven by a common control and no independent throttle valve is provided for each of the four cylinders, the intake device can have a simple structure.

The intake passage 61-1 is provided with a first injector 70-1 for injecting fuel into the intake passage 61-1, and the intake passage 61-2 has a second injector for injecting fuel into the intake passage 61-2. An injector 70-2 is provided, a third injector 70-3 for injecting fuel into the intake passage 61-3 is provided in the intake passage 61-3, and an intake passage 61-4 is provided in the intake passage 61-4. A fourth injector 70-4 for injecting fuel is provided inside.
Here, the first injector 70-1 is disposed downstream of the throttle valve 63-1, the second injector 70-2 is disposed downstream of the throttle valve 63-2, and the third injector 70-3 is disposed. The fourth injector 70-4 is disposed on the downstream side of the throttle valve 63-3.
A first spark plug 71-1 for igniting the air-fuel mixture supplied to the combustion chamber 20-1 is provided at the center of the combustion chamber 20-1, and the combustion chamber 20-2 is provided at the center of the combustion chamber 20-2. A second ignition plug 71-2 for igniting the air-fuel mixture supplied to the combustion chamber 20-3 is provided, and a third ignition plug 71- for igniting the air-fuel mixture supplied to the combustion chamber 20-3 is provided at the center of the combustion chamber 20-3. 3 and a fourth spark plug 71-4 for igniting the air-fuel mixture supplied to the combustion chamber 20-4 is provided at the center of the combustion chamber 20-4.
A cam chain chamber 35 extending vertically is provided at the right ends of the front bank Bf and the rear bank Br, and the camshaft 25 is driven by the crankshaft 2 and passes through the cam chain chamber 35 (not shown). Omitted).

In the present embodiment, the rear bank Br is provided with a cylinder deactivation mechanism 80 (variable valve mechanism) that deactivates the cylinder while maintaining the intake valve 11 and the exhaust valve 12 in the closed state. The cylinder deactivation mechanism 80 is provided between the valve stem end 11d of the intake valve 11 and the intake cam 30 on the intake side, and the valve stem end 12d of the exhaust valve 12 and the rocker arm 27 tappet screw 27b on the exhaust side. It is provided between.
The cylinder deactivation mechanism 80 switches between the operation / non-operation of the pressing force in the valve opening direction from the intake cam 30 to the intake valve 11 and the operation / non-operation of the valve opening direction from the rocker arm 27 to the exhaust valve 12. In a specific operating range of the internal combustion engine 1, for example, in a low load range such as a low speed operating range, the pressing force is made inactive and the intake valve 11 and the exhaust valve 12 are put into a resting state. That is, the cylinder deactivation mechanism 80 is a variable valve mechanism that can switch whether to operate the intake valve 11 and the exhaust valve 12.

FIG. 4 is an enlarged sectional view of the cylinder deactivation mechanism 80 on the intake side.
Since the cylinder deactivation mechanism 80 is similarly configured on the intake side and the exhaust side, the cylinder deactivation mechanism 80 on the intake side will be mainly described here. In addition, the cylinder deactivation mechanism 80 is provided in each of the second cylinder C2 and the third cylinder C3 and has the same configuration, and therefore, the cylinder deactivation mechanism 80 of the second cylinder C2 will be described here.

  As shown in FIG. 4, the cylinder deactivation mechanism 80 is provided in the valve lifter 13, and lifts up and down in the axial direction of the valve stem 11 c (valve stem 12 c on the exhaust side) by the pressing force from the camshaft 25. 85, a slide pin 86 (engagement pin) that is provided in the lifter 85 and slides in a direction orthogonal to the axial direction of the valve stem end 11d, a slide pin holder 87 that holds the slide pin 86, and a slide pin 86 A hydraulic pressure supply mechanism 88 that applies hydraulic pressure to the slide pin 86, a return spring 89 that biases the slide pin 86 against the hydraulic pressure applied to the slide pin 86, and a lifter 85 that biases the lifter 85 against the pressing force from the camshaft 25. An urging spring 90 is provided.

The lifter 85 is formed in a cylindrical shape having a flat upper end in the axial direction, has an open bottom surface, and accommodates a disk-shaped slide pin holder 87 therein. A communication hole 85 a is formed on the outer peripheral surface of the lifter 85 to communicate the inside and outside of the lifter 85.
The lifter 85 is slidably supported in a cylindrical lifter support portion 91 provided on the upper portion of the rear cylinder head 4r. An oil supply groove 91 a is formed on the inner peripheral surface of the lifter support portion 91 so as to surround the lifter 85.

The hydraulic pressure supply mechanism 88 includes an oil pump 50 (see FIG. 2) for sending hydraulic oil, an oil passage 72 (see FIG. 3) connected to the oil pump 50, and the second cylinder C2 and the third cylinder from the oil passage 72. Control oil passages 73 and 74 branching to C3, a hydraulic pressure switching unit 75 for switching the hydraulic oil flowing through the control oil passages 73 and 74, and an oil supply groove 91a positioned at the end of the control oil passages 73 and 74 are provided. .
Here, the oil passage 72 is provided with an oil temperature sensor 99 for detecting the oil temperature in the oil passage 72 and a first oil pressure sensor 100-1 for detecting the oil pressure in the oil passage 72, and the control oil passage. 73 is provided with a second hydraulic pressure sensor 100-2 for detecting the hydraulic pressure in the control oil passage 73, and the control oil passage 74 is provided with a third hydraulic pressure sensor 100-3 for detecting the hydraulic pressure in the control oil passage 74. ing.
The hydraulic pressure switching unit 75 supplies the first spool valve 75a for switching ON / OFF the hydraulic pressure of the hydraulic oil supplied to the cylinder deactivation mechanism 80 of the second cylinder C2 and the cylinder deactivation mechanism 80 of the third cylinder C3. A second spool valve 75b that switches ON / OFF of the hydraulic pressure of the hydraulic oil to be supplied. Switching between the first spool valve 75a and the second spool valve 75b is controlled by the ECU 76 on the basis of the operating state of the vehicle such as the rotational speed of the internal combustion engine 1 (engine speed).

As shown in FIG. 4, the slide pin holder 87 includes a cylinder hole 87 a that extends in the radial direction of the disk shape and faces in a direction orthogonal to the valve stem 11 c, and a valve stem at the center of the slide pin holder 87. 11c and a stem hole 87b provided coaxially. An opening 87c is provided at one end of the cylinder hole 87a, and a wall portion 87d is formed at the other end. A stopper pin 92 that restricts the position of the slide pin 86 in the cylinder hole 87a is provided on the opening 87c side of the cylinder hole 87a.
A tappet clearance adjusting shim 94 is interposed between the upper surface of the slide pin holder 87 and the pressed surface of the lifter 85. The biasing spring 90 is provided in contact with the lower surface of the slide pin holder 87.

  The slide pin 86 is slidably provided in the cylinder hole 87a and has an escape hole 93 that penetrates in a direction orthogonal to the axial direction thereof. Further, the slide pin 86 has a receiving portion 93 a whose outer peripheral surface is recessed inward, and the receiving portion 93 a is provided continuously to the escape hole 93. In the cylinder hole 87a, a space between one end of the slide pin 86 and the lifter 85 is a hydraulic chamber 95 in which the hydraulic oil acts.

A return spring 89 is provided between the other end of the slide pin 86 and the wall portion 87d of the cylinder hole 87a. As shown in FIG. 4, the return spring 89 moves the slide pin 86 to the hydraulic chamber 95 side. Energized. The position of the slide pin 86 in the axial direction is regulated by fitting the stopper pin 92 in a groove provided on one end side. In a state where the slide pin 86 is pressed against the stopper pin 92 side, the escape hole 93 is located closer to the hydraulic chamber 95 than the stem hole 87b.
When hydraulic oil is supplied to the hydraulic chamber 95 and the slide pin 86 slides to the other end side against the return spring 89, the escape hole 93 is coaxial with the stem hole 87b and communicates with the stem hole 87b. The diameter of the escape hole 93 is formed larger than the diameter of the valve stem end 11d.

The valve stem end 11 d of the intake valve 11 is inserted into the stem hole 87 b and is engaged with the receiving portion 93 a of the slide pin 86. In the cylinder deactivation mechanism 80, the engagement state between the valve lifter 13, the intake valve 11, and the exhaust valve 12 is changed by sliding the slide pin 86.
In the cylinder deactivation mechanism 80, when the first spool valve 75a is controlled to be in the OFF state, the hydraulic pressure acting on the slide pin 86 is low, and the slide pin 86 is not moved to the other end side against the return spring 89, the valve stem The end 11d contacts the receiving portion 93a, and the intake valve 11 is connected to the lifter 85. For this reason, when the lifter 85 is pressed and lowered through the intake cam 30 by the rotation of the camshaft 25, a pressing force acts on the intake valve 11 through the receiving portion 93a of the slide pin 86, and the intake valve 11 is opened. As the lifter 85 reciprocates, the cylinder is in an operating state in which the intake valve 11 opens and closes.

  Further, when the cylinder deactivation mechanism 80 is activated and the first spool valve 75a is controlled to be in the ON state and the hydraulic oil is supplied to the hydraulic chamber 95, the slide pin 86 moves to the other end side against the return spring 89. Thus, the escape hole 93 of the slide pin 86 communicates with the stem hole 87 b, and the valve stem end 11 d of the intake valve 11 can be fitted into the escape hole 93. In this state, when the lifter 85 is pressed and reciprocated via the intake cam 30 by the rotation of the camshaft 25, the lifter 85 reciprocates up and down independently with the valve stem end 11d of the intake valve 11 fitted. The pressing force of the intake cam 30 is not transmitted to the intake valve 11. That is, the intake valve 11 is in a cylinder deactivation state in which the pressing force of the camshaft 25 does not act even when the camshaft 25 rotates and the valve closing state is maintained.

  The cylinder deactivation mechanism 80 is provided in all the intake valves 11 and exhaust valves 12 in the second cylinder C2, and when the second cylinder C2 is deactivated, all the intake valves 11 and exhaust valves in the second cylinder C2 are provided. 12 is put into a dormant state. Also, in the third cylinder C3, as in the second cylinder C2, all the intake valves 11 and the exhaust valves 12 are provided with cylinder deactivation mechanisms 80. When the third cylinder C3 is deactivated, the third cylinder C3 All the intake valves 11 and exhaust valves 12 in C3 are put into a resting state. That is, the rear bank Br composed of the second cylinder C2 and the third cylinder C3 is a deactivated cylinder that can be deactivated. Further, the internal combustion engine 1 is operated with four cylinders for operating all four cylinders, with two cylinders for stopping the second cylinder C2 and the third cylinder C3, and with either one of the second cylinder C2 or the third cylinder C3 being stopped. The three-cylinder operation can be performed.

The ECU 76 switches the first spool valve 75a and the second spool valve 75b of the cylinder deactivation mechanism 80 in accordance with the driving condition of the vehicle to control the cylinder deactivation of the rear bank Br. Then, the fuel supply to the injector 70 of the cylinder to be stopped is stopped. For this reason, the fuel consumption of the internal combustion engine 1 can be improved.
On the other hand, the first cylinder C1 and the fourth cylinder C4 do not have the cylinder deactivation mechanism 80, and the front bank Bf is a normally operated cylinder in which the intake valve 11 and the exhaust valve 12 are always opened and closed when the internal combustion engine 1 is operated. It is.

By the way, in the internal combustion engine 1, in order to check whether or not the cylinder deactivation mechanism 80 driven by hydraulic pressure is operating normally as instructed by the ECU 76, the valve operation determination for determining the operating state of the cylinder deactivation mechanism 80 is performed. A portion 96 is provided.
The valve operation determination unit 96 includes a second intake pressure sensor 97-2 that detects the pressure of intake air supplied to the second cylinder C2, and a third intake pressure sensor that detects the pressure of intake air supplied to the third cylinder C3. 97-3 and ECU76.
The front bank Bf is provided with a first intake pressure sensor 97-1 for detecting the pressure of intake air supplied to the first cylinder C1 and the fourth cylinder C4.

  The first intake pressure sensor 97-1 is provided on the front throttle body 60f, and is disposed on the downstream side of the throttle valves 63-1 and 63-4. More specifically, a single first intake pressure sensor 97-1 is provided in common for the front throttle body 60f, and the intake passages 61-1 and 61- are provided by one first intake pressure sensor 97-1. 4, the intake pressure downstream of the throttle valves 63-1 and 63-4 is measured. That is, in the front bank Bf, the intake pressure of the first cylinder C1 and the fourth cylinder C4 is output to the ECU 76 as a detected value detected by one first intake pressure sensor 97-1 as the intake pressure of the front bank Bf. The

The second intake pressure sensor 97-2 is provided in the rear throttle body 60r and is disposed on the downstream side of the throttle valve 63-2. Specifically, one second intake pressure sensor 97-2 is provided in the intake passage 61-2 of the second cylinder C2, and is downstream of the throttle valve 63-2 in the intake passage 61-2 of the second cylinder C2. Measure the intake pressure.
The third intake pressure sensor 97-3 is provided in the rear throttle body 60r, and is disposed downstream of the throttle valve 63-3. Specifically, one third intake pressure sensor 97-3 is provided in the intake passage 61-3 of the third cylinder C3, and is downstream of the throttle valve 63-3 in the intake passage 61-3 of the third cylinder C3. Measure the intake pressure.
That is, in the rear bank Br, the intake pressure of the second cylinder C2 or the third cylinder C3 is detected by the second intake pressure sensor 97-2 and the third intake pressure sensor 97-3 that are individually provided for each cylinder. And output to the ECU 76.

  Each intake pressure detected by the first intake pressure sensor 97-1, the second intake pressure sensor 97-2, and the third intake pressure sensor 97-3 is processed by the ECU 76, and the ECU 76 The fuel injection amount of each of the injectors 70-1 to 70-4 is determined based on the operation state such as the accelerator opening.

The ECU 76 operates the cylinder deactivation mechanisms 80 of the second cylinder C2 and the third cylinder C3 based on the intake pressures detected by the second intake pressure sensor 97-2 and the third intake pressure sensor 97-3. Determine the state.
Specifically, the second intake pressure sensor 97-2 will be described as an example. When the cylinder deactivation mechanism 80 is in the OFF state and the second cylinder C2 is not deactivated, the intake passage 61- of the second cylinder C2 is taken. Since the intake air continuously flows to 2, the intake pressure of the intake passage 61-2 of the second cylinder C2 becomes a negative pressure lower than the atmospheric pressure. On the other hand, when the cylinder deactivation mechanism 80 is ON and the second cylinder C2 is deactivated, the intake valve 11 is closed and intake air does not flow continuously into the intake passage 61-2 of the second cylinder C2. The intake pressure in the intake passage 61-2 of the second cylinder C2 is close to atmospheric pressure.

In the present embodiment, when the detected value of the second intake pressure sensor 97-2 is a negative pressure lower than a predetermined intake pressure, the ECU 76 determines that the cylinder deactivation mechanism 80 is inactive, When the detection value of the two intake pressure sensor 97-2 is higher than the predetermined intake pressure, it is determined that the cylinder deactivation mechanism 80 is in an operating state. The predetermined intake pressure is determined by clarifying the relationship between the intake pressure in the intake passage 66 and the actual operating state of the cylinder deactivation mechanism 80 in advance through experiments, and associating the relationship between the two. The predetermined intake pressure may be variable according to the driving situation.
Further, the third cylinder C3 is configured in the same manner as the second cylinder C2, and when the detected value of the third intake pressure sensor 97-3 is a negative pressure lower than a predetermined intake pressure, When it is determined that the cylinder deactivation mechanism 80 is in an inoperative state and the value of the third intake pressure sensor 97-3 is greater than a predetermined intake pressure, the cylinder deactivation mechanism 80 of the third cylinder C3 is in an operational state. Is determined.

As described above, the operating state of the cylinder deactivation mechanism 80 using the second intake pressure sensor 97-2 and the third intake pressure sensor 97-3 used for determining the fuel injection amounts of the injectors 70-2 and 70-3. Therefore, the operating state of the cylinder deactivation mechanism 80 can be detected without providing a dedicated mechanism, and the operating states of the intake valve 11 and the exhaust valve 12 can be reliably captured.
Further, by detecting the intake pressures of the second cylinder C2 and the third cylinder C3, the operating state of the cylinder deactivation mechanism 80 is directly determined based on the fluctuation of the intake pressure generated as a result of the actual operation of the cylinder deactivation mechanism 80. Therefore, the operating state can be accurately determined. For example, it is conceivable to determine the operating state of the cylinder deactivation mechanism 80 by detecting the hydraulic pressure of the cylinder deactivation mechanism 80. In this case, the structure is complicated and the operation state of the cylinder deactivation mechanism 80 is indirectly determined. It will be judged.
In addition, since the second intake pressure sensor 97-2 is provided in the second cylinder C2, the third intake pressure sensor 97-3 is provided in the third cylinder C3, and the intake pressure sensor is provided independently for each cylinder that can be stopped. Even in the case of three-cylinder operation, the operating state of the cylinder deactivation mechanism 80 can be reliably captured using the second intake pressure sensor 97-2 or the third intake pressure sensor 97-3.

FIG. 5 is a schematic configuration block diagram of the control system.
On the input side of the ECU 76, a first intake pressure sensor 97-1, a second intake pressure sensor 97-2, a third intake pressure sensor 97-3, a front knock sensor 98-1, a rear knock sensor 98-2, oil The temperature sensor 99, the first hydraulic sensor 100-1, the second hydraulic sensor 100-2, the third hydraulic sensor 100-3, and the accelerator position sensor 101 that outputs a signal corresponding to the accelerator opening (grip opening) are connected. ing.
Further, on the output side of the ECU 76, there are a first injector 70-1, a second injector 70-2, a third injector 70-3, a fourth injector 70-4, a first spark plug 71-1, a second spark plug 71. -2, third spark plug 71-3, fourth spark plug 71-4, first spool valve 75a, and second spool valve 75b are connected.
Here, the first spark plug 71-1, the second spark plug 71-2, the third spark plug 71-3, and the fourth spark plug 71-4 are not actually directly connected to the ECU 76. These are connected to the ECU 76 via an ignition coil drive unit and an ignition coil (not shown), respectively, and the ECU 76 performs ignition control by outputting a drive control signal including an ignition stop flag signal to be described later to the ignition coil drive unit. Is going.

Next, the principle operation when shifting from cylinder deactivation to cylinder operation in the embodiment will be described.
FIG. 6 is an explanatory diagram of the principle operation during cylinder deactivation.
In FIG. 6, it is assumed that in the initial state, the second cylinder C2 is in the cylinder deactivation state, and the first spool valve 75a is in the ON state until immediately before time t01. Further, it is assumed that the fuel injection and ignition of the spark plug are stopped after time t0 with the cylinder inactive state of the second cylinder C2. In FIG. 6, from time t01 to time t02, the fuel injection timing and the ignition plug ignition timing during cylinder operation are shown, but the fuel injection and ignition plug ignition are stopped.
Then, in the cylinder deactivation state of the second cylinder C2, as described above, the cylinder deactivation mechanism 80 operates, and even if the lifter 85 is pressed via the intake cam 30 by the rotation of the camshaft 25 and reciprocates, No. 85 is only reciprocating up and down independently with the valve stem end 11d of the intake valve 11 being fitted. The pressing force of the intake cam 30 is not transmitted to the intake valve 11, and the intake valve 11 is connected to the camshaft 25. Even if is rotated, the pressing force of the camshaft 25 does not act, and the valve closed state is maintained. Similarly, the cylinder deactivation mechanism 80 corresponding to the exhaust valve 12 is also operated, and the valve closed state is maintained.

  In this state, the first spool valve 75a is turned off at time t01, but the hydraulic pressure detected by the second hydraulic pressure sensor 100-2 is the cylinder until time t02 as shown in FIG. The switching hydraulic pressure Vsw that can be switched from the deactivation state to the cylinder operation state is exceeded, and the cylinder deactivation state in which the intake valve 11 and the exhaust valve 12 of the second cylinder C2 are maintained in the closed state is maintained.

  When the time t02 has elapsed and the oil pressure detected by the second oil pressure sensor 100-2 is below the switching oil pressure Vsw that can be switched from the cylinder deactivation state to the cylinder operation state, the slide pin 86 resists the return spring 89. The valve stem end 11d of the intake valve 11 constituting the second cylinder C2 comes into contact with the receiving portion 93a, and the intake valve 11 is connected to the lifter 85. Similarly, the exhaust valve 12 is connected to the lifter 85 of the corresponding cylinder deactivation mechanism 80.

For this reason, when the lifter 85 is pressed and lowered through the intake cam 30 by the rotation of the camshaft 25, a pressing force acts on the intake valve 11 through the receiving portion 93a of the slide pin 86, and the intake valve 11 and the exhaust valve. 12 can be opened and closed.
Accordingly, when the drive timing of the intake valve 11 is reached, the intake valve 11 opens and closes with the corresponding reciprocating movement of the lifter 85, and when the drive timing of the exhaust valve 12 is reached, the exhaust valve is moved with the corresponding reciprocating motion of the lifter 85. 12 shifts to a cylinder operating state in which opening and closing operation is possible.

Therefore, at time t03, the intake valve 11 is started to operate and the intake stroke is started. At time t04, fuel is injected into the intake passage 61-2 by the second injector 70-2.
Then, when the intake stroke and the compression stroke are completed and a predetermined ignition timing is reached at time t05, ignition is performed by the second ignition plug 71-2 of the second cylinder C2, the expansion stroke is reached, and the internal combustion engine 1 is driven. Will be.

Next, actual cylinder deactivation / operation control during vehicle travel will be described.
FIG. 7 is a process flowchart of cylinder deactivation / operation control.
First, the ECU 76 determines whether the second cylinder C2 or the third cylinder C3 corresponds to the accelerator opening (grip opening) and the engine speed NE (or vehicle speed, the same applies hereinafter) according to the output signal of the accelerator position sensor 101. It is determined whether or not to perform a pause or operation (step S10).
Subsequently, the ECU 76 determines whether or not there is a cylinder (second cylinder C2 or third cylinder C3) that should be in a cylinder deactivation state (step S11).

If it is determined in step S11 that there is a cylinder to be brought into the cylinder deactivation state (step S11; Yes), the ECU 76 determines the first based on the engine speed NE and the oil temperature detected by the oil temperature sensor 99. The timing (corresponding to a stage to be described later) for stopping the fuel injection by the 2 injectors 70-2 or the third injector 70-3 is calculated, and the flag for stopping the fuel injection is turned on at the corresponding timing (step S12). . In this embodiment, an air cycle that does not perform fuel injection and ignition is provided prior to the transition to cylinder deactivation, so the timing for turning on the flag for stopping fuel injection is the actual timing described above. It is not limited to the fuel injection timing, and it may be after the fuel is injected and before the intake stroke in the cycle corresponding to the air cycle in the intake stroke of the 4-cycle cycle immediately before the cycle corresponding to the air cycle.
Subsequently, the ECU 76 starts counting of an ignition stop waiting counter for detecting the timing (stage) at which ignition is stopped in accordance with the engine speed NE and the oil temperature detected by the oil temperature sensor 99. At a timing (stage) corresponding to the count value of the stop waiting counter, the ignition stop flag signal is turned on and output to an ignition coil driving unit (not shown) (step S13). As a result, the ignition coil driving unit stops driving the ignition coil and stops ignition of the spark plug.

  Furthermore, the ECU 76 stops fuel injection by the second injector 70-2 or the third injector 70-3 based on the engine speed NE and the oil temperature detected by the oil temperature sensor 99 (corresponding to a stage described later). ) Starts counting of the cylinder deactivation waiting counter for detecting the timing (stage) for executing cylinder deactivation, starts counting of the cylinder deactivation waiting counter, and performs cylinder deactivation at the timing (stage) for executing cylinder deactivation. Is executed, the cylinder deactivation signal is output to activate the cylinder deactivation mechanism 80 (step S14).

On the other hand, if it is determined in step S11 that there is a cylinder to be in the cylinder operating state (step S11; No), the ECU 76 is based on the engine speed NE and the oil temperature detected by the oil temperature sensor 99. The timing (stage) at which execution of cylinder operation is started is calculated, a cylinder operation signal is output at this timing, and the operation of the cylinder deactivation mechanism 80 is stopped (step S15).
Subsequently, the ECU 76 starts the second spark plug 71-2 or the third from the timing (stage) at which the cylinder operation is started based on the engine speed NE and the oil temperature detected by the oil temperature sensor 99. The count of the ignition start waiting counter for detecting the timing (stage) for starting ignition by the spark plug 71-3 is started, and the ignition stop flag signal is turned off at the timing (stage) corresponding to the count value of the ignition start waiting counter. Then, it outputs to the ignition coil drive part which is not illustrated (step S16). As a result, thereafter, the ignition coil driving unit restarts the driving of the ignition coil and ignites the spark plug. The timing at which the ignition stop flag signal is turned off, that is, the timing at which the ignition permission of the ignition plug is started is after the ignition timing corresponding to the expansion stroke immediately before shifting to cylinder operation, and after the cylinder operation. Any period may be used until the ignition timing is reached.

  Further, the ECU 76 starts the second injector 70-2 or the third injector 70- from the timing (stage) at which the cylinder operation is started based on the engine speed NE and the oil temperature detected by the oil temperature sensor 99. 3 is started, and the flag for stopping the fuel injection is turned off at the corresponding timing (step S17).

  In parallel with the processing in steps S10 to S17, interrupt processing is performed at predetermined timings (for example, every 2 ms), and TBW throttle valves 63-1, corresponding to the first cylinder C1 and the fourth cylinder C4, 63-4 (first system), TBW type throttle valve 63-2 (second system) corresponding to the second cylinder C2, and TBW type throttle valve 63-3 (third) corresponding to the third cylinder C3. In the three systems of throttle valves 63-1 to 63-4, the target throttle valve opening calculation step for calculating the optimum target throttle valve opening for each system and the target throttle valve opening calculation step are calculated. Throttle that controls the three throttle valves 63-1 to 63-4 for each system so that the throttle valve opening is set Lube opening control step is executed.

Next, specific cylinder deactivation / operation control will be described.
FIG. 8 is a processing timing chart of more specific cylinder deactivation / operation control.
In FIG. 8, the four consecutive strokes (intake stroke, compression stroke, expansion stroke, exhaust stroke) of the internal combustion engine 1 as a four-cycle engine are composed of 28 stages (7 stages for each stroke) for convenience of explanation. Assume that timing control is performed in units of stages.
First, referring to FIG. 8 (a), the operation when shifting from the cylinder operating state to the cylinder deactivation state will be described.
In the following description, a case where cylinder deactivation of the second cylinder C2 in the cylinder operating state in the initial state is performed will be described as an example.
In the intake stroke in the second cylinder C2, the fuel is injected by the second injector 70-2 at time t1, and then the exhaust is exhausted at time t2 through the compression stroke and the expansion stroke in which ignition is performed by the second spark plug 71-2. The valve 12 is opened and the exhaust stroke is performed.

Subsequently, at time t3, the intake valve 11 is opened, and the process proceeds to the intake stroke.
Here, when the first spool valve 75a is driven, the cylinder deactivation mechanism 80 corresponding to both the intake valve 11 and the exhaust valve 12 of the second cylinder C2 to bring the second cylinder C2 into the cylinder deactivation state. Therefore, the intake valve 11 of the second cylinder C2 is securely connected in consideration of the time lag of the hydraulic system for operating the cylinder deactivation mechanism 80 in order to make the second cylinder C2 in the cylinder deactivation state. It is necessary to give an instruction to the period TM1 during which the exhaust valve 12 of the second cylinder C2 can be reliably closed and the period TM2 during which the exhaust valve 12 of the second cylinder C2 can be reliably closed.
Here, in order to reduce the torque shock due to the change in the number of cylinders, the fuel injection and ignition plug ignition are not performed before the intake valve 11 and the exhaust valve 12 start shifting to the rest state. It is necessary to keep.
More specifically, a stop instruction is issued during a period in which the intake valve 11 can be reliably stopped (a period indicated by a thick solid line TM1 in FIG. 8A), and the intake valve 11 is securely connected. It is necessary not to issue a pause instruction during a period during which no pause is possible (a period other than the period indicated by the thick solid line TM1 in FIG. 8A). Here, the period during which the intake valve 11 can be reliably stopped is a period during which fuel to be combusted remains in the combustion chamber (after fuel injection and before ignition), or in the combustion chamber. This is a period in which the intake valve 11 can be stopped for cylinder deactivation in a period excluding a period in which exhaust after combustion remains (period after ignition and before exhaust).

Similarly, a pause instruction is issued during a period during which the exhaust valve 12 can be reliably stopped (a period indicated by a thick solid line TM2 in FIG. 8A), and the exhaust valve 12 cannot be reliably stopped (FIG. 8). In (a), it is necessary not to give a pause instruction during a period other than the period indicated by the thick solid line TM2. Here, the period during which the exhaust valve 12 can be reliably stopped is a period during which fuel to be combusted remains in the combustion chamber (a period after fuel injection and before ignition), or in the combustion chamber. This is a period during which the exhaust valve 12 can be stopped for cylinder deactivation in a period excluding a period in which exhaust after combustion remains (period after ignition and before exhaust).
Therefore, in practice, the ECU 76 needs to issue a cylinder deactivation instruction within a period TE1 corresponding to time t4 to time t7, which is a period common to the period indicated by the thick solid line TM1 and the period indicated by the thick solid line TM2. There is. Here, the timing for actually instructing cylinder deactivation within the period TE1 is determined by the oil temperature corresponding to the output of the oil temperature sensor 99, the engine speed NE, and the first to third hydraulic sensors 100-1 to 100-3. Based on the detected oil pressure (particularly, the oil pressure detected by the first oil pressure sensor 100-1), it is determined in consideration of the crank rotation angle, the camshaft rotation angle, and the time lag of the hydraulic system in consideration of their angular velocities. If the oil temperature or oil pressure is high, the time lag of the hydraulic system becomes small.

Prior to this, it is necessary to stop the fuel injection. The timing at which the stop of the fuel injection is started is at least before the intake stroke one cycle before the cycle of the four cycles for actually shifting to cylinder deactivation, and the fuel injection in which the fuel burned last is injected It may be after the timing. This is to provide a later-described air cycle that takes in only air that does not include fuel in the intake stroke at least one cycle before the cycle of the four cycles that are actually shifted to cylinder deactivation. This is to prevent the fuel from being consumed unnecessarily during the pause.
Therefore, at the time t5, the ECU 76 causes the fuel to be injected by the second injector 70-2 at the timing at which the fuel is injected by the second injector 70-2, that is, the third stage among the 28 stages described above. In step S12 in FIG. 7, it is determined whether or not to stop the fuel injection, and the injection stop flag is set to be turned on in the third stage. The state where the injection stop flag is on is continued until the cylinder deactivation is canceled and the cylinder is operated, and fuel injection is continuously stopped.
As a result, fuel injection by the second injector 70-2 is prohibited at the third stage corresponding to time t5. Thereafter, at time t6, the ECU 76 outputs a deactivation instruction so that the second cylinder C2 can enter the deactivation state at time t9 in consideration of the time lag of the hydraulic system for operating the cylinder deactivation mechanism 80.

In parallel with this, at time t6, the exhaust stroke is reached and the exhaust valve 12 is opened and exhausted. At time t8, the intake stroke is reached and the intake valve 11 is opened and gas exchange is performed. Inhalation is done (air cycle). As a result, the introduced air is taken into the cylinder, and the spark plug (the second spark plug 71-2 in the second cylinder C2) is switched when the cylinder is deactivated to the cylinder operating state. It is possible to suppress smoldering due to adhering lubricating oil.
Then, at time t9, from the timing at which the ECU 76 stops fuel injection by the second injector 70-2 at time t5 (corresponding to a stage described later) in the intake stroke, the 0th stage corresponding to time t9 at which cylinder deactivation is performed. When the count of the cylinder deactivation waiting counter is completed at time t9, the cylinder deactivation mechanism 80 is activated, and the second cylinder C2 is in the cylinder deactivation state. Become. In this case, the count value of the cylinder deactivation waiting counter corresponds to the time lag of the hydraulic system for operating the cylinder deactivation mechanism 80 predicted by the ECU 76, and after this, the cylinder deactivation state is surely established. Is guaranteed.

As a result, after time t10, the exhaust valve 12 and the intake valve 11 are kept closed by broken lines in FIG. 8A until the cylinder deactivation is canceled due to various conditions.
Next, with reference to FIG. 8B, the operation when shifting from the cylinder deactivation state to the cylinder operation state will be described.
In the following description, a case where the cylinder operation of the second cylinder C2 that is in the inactive state in the initial state is performed will be described as an example.
In the second cylinder C2 in the cylinder deactivation state, the time t21 is originally a timing at which the intake valve 11 is opened and shifts to the intake stroke, but since the cylinder is still in the cylinder deactivation state, the intake valve 11 is closed. The state remains.

By the way, even if the driving of the first spool valve 75a is stopped, in order to stop the operation of the cylinder deactivation mechanism 80 and to bring the second cylinder C2 into the cylinder operating state, it takes a certain amount of time due to the time lag of the hydraulic system. Is required.
That is, in order to place the second cylinder C2 in the cylinder operating state, both the intake valve 11 and the exhaust valve 12 of the second cylinder C2 can be reliably started by the corresponding cylinder deactivation mechanisms 80, In order to put the two cylinders C2 into the cylinder operating state, it is possible to reliably start the intake valve 11 of the second cylinder C2 in consideration of the time lag of the hydraulic system for stopping the cylinder deactivation mechanism 80. It is necessary to give an instruction during the period and the period during which the exhaust valve 12 of the second cylinder C2 can be reliably started.
Further, in order to reduce the torque shock caused by the change in the number of cylinders, it is necessary to prevent the fuel injection and the ignition plug from being ignited before the intake valve 11 and the exhaust valve 12 complete the transition to the operating state. is there.
In order to start operation of both the intake valve 11 and the exhaust valve 12, it is necessary to start the operation of the exhaust valve 12 first. This is to prevent the charging efficiency ηv in the first combustion stroke from being affected by the amount of air in the combustion chamber during the cylinder stop period.

That is, the operation start instruction is issued during a period in which the intake valve 11 of the second cylinder C2 can be reliably started (period indicated by the thick solid line TM11 in FIG. 8B), and the intake valve 11 is reliably It is necessary not to issue an operation start instruction during a period during which operation cannot be started (period other than the period indicated by the thick solid line TM11 in FIG. 8B).
More specifically, an operation start instruction is issued during a period during which the intake valve 11 can be reliably started (period indicated by a thick solid line TM11 in FIG. 8B), and the intake valve 11 is reliably operated. It is necessary not to issue a pause instruction during a period in which it cannot start (a period indicated by a thick broken line before and after the thick solid line TM1 in FIG. 8B).
Here, the period during which the intake valve 11 can be reliably started is a period in which the exhaust valve 12 is started first (corresponding to an exhaust stroke), and the intake valve is reliably supplied in the intake stroke immediately after the exhaust stroke. 11 is a period during which the operation can be performed.
Similarly, an operation start instruction is issued during a period in which the exhaust valve 12 can be reliably stopped (the period indicated by the thick solid line TM12 in FIG. 8B), and the exhaust valve 12 cannot be reliably stopped (see FIG. 8). 8 (a), it is necessary not to issue an operation start instruction during a period indicated by a thick broken line following the thick solid line TM2.
Here, the period during which the exhaust valve 12 can be reliably started is considered to be the operation of the exhaust valve 12 prior to the intake valve 11 after the actual start of cylinder operation in consideration of the time lag of the hydraulic system. Is a period in which

Therefore, actually, the ECU 76 issues an instruction to start cylinder operation within a period TE2 corresponding to time t22 to time t25, which is a period common to the period indicated by the thick solid line TM1 and the period indicated by the thick solid line TM12. There is a need.
In this case, the time t23 is a timing at which the exhaust valve 12 is originally opened and the transition to the exhaust stroke is started, but the exhaust valve 12 remains closed because the cylinder is still in the idle state. .
Then, at the 26th stage corresponding to time t24, the ECU 76 considers the time lag of the hydraulic system to stop the operation of the cylinder deactivation mechanism 80, and at time t26, that is, from the first exhaust stroke after the start of the cylinder. An operation start instruction is output so that the second cylinder C2 can shift to the operation state at the previous timing. When the drive stop signal of the first spool valve 75a as an operation start instruction is issued and the time t26 is reached and the count of the cylinder operation start waiting counter is completed, the cylinder deactivation mechanism 80 is in the operation stop state, and the second cylinder C2 is in the cylinder operating state.

At time t27, the process proceeds to the exhaust stroke, and fuel is injected by the second injector 70-2. Thereafter, at time t28, the exhaust valve 12 is opened, and the exhaust stroke is executed.
Subsequently, at time t29, the intake valve 11 is opened and the operation proceeds to the intake stroke. Hereinafter, the second cylinder C2 is in the cylinder operating state and operates as usual.
In the above description, the normal mutual transition between the cylinder deactivation state and the cylinder operation state has been described. However, in the internal combustion engine 1 having the cylinder deactivation mechanism as in the present embodiment, the load is low as in idling. It is possible to improve fuel efficiency by performing cylinder deactivation at low engine speeds, but when the period of low load and low engine speeds becomes longer, lubricating oil enters the combustion chamber due to oil rise, The invading lubricating oil may adhere to the spark plugs (in this embodiment, the spark plugs 71-2 and 71-3), thus causing smoldering in the spark plug to which the lubricating oil has adhered. It was.

Therefore, in this embodiment, when the load is low, the engine speed is low, or the vehicle speed is low, cylinder deactivation is stopped (interrupted), and all cylinders are set to operating cylinders, so that they adhere to the spark plug during combustion in the expansion stroke. The structure which removes the lubricating oil which did is taken.
Hereinafter, the structure which removes the lubricating oil adhering to a spark plug specifically and prevents smoldering is demonstrated.
FIG. 9 is a process flowchart in a case where all cylinders are operating cylinders at low load and low engine speed.

First, the ECU 76 detects the load and engine speed of the engine that is the internal combustion engine 1 (step S20).
Subsequently, the ECU 76 determines whether there is a cylinder to be deactivated based on the detected engine load and engine speed (step S21).
If it is determined in step S21 that there is no cylinder to be deactivated, all four cylinders are operating cylinders. Therefore, the process proceeds to step S20 again, and the same process is performed thereafter.
If it is determined in step S21 that there is a cylinder to be deactivated (step S21; Yes), the cylinder to be deactivated (in this embodiment, the second cylinder C2 or the third cylinder C3) is determined by the method described above. The sleep state is set (step S22).

For example, in a case where it is sufficient to set three cylinders in an operating state among all four cylinders C1 to C4, the third cylinder C3 is deactivated (step S).
Next, the ECU 76 determines whether or not a predetermined time has elapsed since the cylinder that first shifted to the cylinder deactivation state among the cylinders that are currently in the cylinder deactivation state has shifted to the cylinder deactivation state (step S23).
In the determination in step S23, when a predetermined time has not elapsed since the cylinder that first shifted to the cylinder deactivation state among the cylinders that are currently in the cylinder deactivation state has entered the cylinder deactivation state, the cylinder enters a standby state.
Further, in the determination of step S23, when a predetermined time elapses after the cylinder that has first entered the cylinder deactivation state among the cylinders currently in the cylinder deactivation state has entered the cylinder deactivation state, all the cylinders are operated. As a condition, there is a possibility that the lubricating oil that has entered the combustion chamber adheres to the spark plug, and in this way, the lubricating oil adheres to the spark plug so as not to cause smoldering in the spark plug. Remove the lubricant.

  Therefore, the maintenance of the spark plug is facilitated, the idling is stabilized, the combustion efficiency is improved, and the fuel consumption can be improved.

In the above description, the cylinders subject to cylinder deactivation are not limited except for the load and the engine speed. However, if the same cylinder is always subject to cylinder deactivation, the cylinders are long-term. Therefore, there is a higher possibility that the lubricating oil that has entered the combustion chamber adheres to the spark plug.
In view of this, the present modification is for changing the cylinder to be deactivated at any time.

FIG. 10 is a process flowchart in a case where all cylinders are set as operating cylinders at low load and low engine speed, and the cylinders to be deactivated are changed as needed. 10, parts that are the same as those in FIG. 9 are given the same reference numerals.
First, the ECU 76 detects the load and engine speed of the engine that is the internal combustion engine 1 (step S20).
Subsequently, the ECU 76 determines whether there is a cylinder to be deactivated based on the detected engine load and engine speed (step S21).

If it is determined in step S21 that there is no cylinder to be deactivated, all four cylinders are operating cylinders. Therefore, the process proceeds to step S20 again, and the same process is performed thereafter.
If it is determined in step S21 that there is a cylinder to be deactivated (step S21; Yes), the ECU 76 changes the cylinder to be deactivated (in this embodiment, the second cylinder C2 or the third cylinder C3) or Select (step S31).

For example, in a case where it is sufficient to put three cylinders in an operating state among all four cylinders C1 to C4, the third cylinder C3 is deactivated at the nth time, and the second cylinder C2 is at the n + 1th time. Is set to cylinder deactivation, and the cylinders to be deactivated are equally deactivated. To do.
The ECU 76 deactivates the cylinder changed or selected in step S31 by the method described above (step S32).
Next, the ECU 76 determines whether or not a predetermined time has elapsed since the cylinder that first shifted to the cylinder deactivation state among the cylinders that are currently in the cylinder deactivation state has shifted to the cylinder deactivation state (step S23).
In the determination in step S23, when a predetermined time has not elapsed since the cylinder that first shifted to the cylinder deactivation state among the cylinders that are currently in the cylinder deactivation state has entered the cylinder deactivation state, the cylinder enters a standby state.

Further, in the determination of step S23, when a predetermined time elapses after the cylinder that has first entered the cylinder deactivation state among the cylinders currently in the cylinder deactivation state has entered the cylinder deactivation state, all the cylinders are operated. As a condition, there is a possibility that the lubricating oil that has entered the combustion chamber adheres to the spark plug, and in this way, the lubricating oil adheres to the spark plug so as not to cause smoldering in the spark plug. Remove the lubricant.
Therefore, the maintenance of the spark plug is facilitated, the idling is stabilized, the combustion efficiency is improved, and the fuel consumption can be improved.

FIG. 11 is a state transition diagram of the internal combustion engine.
The operation modes of the internal combustion engine are roughly divided into five operation modes.
Specifically, the operation modes of the internal combustion engine 1 include a stop mode M0, a standby mode M1, a constant 4-cylinder mode M2 before warm-up, a normal operation mode M3, and a fail mode M4.
First, when the internal combustion engine 1 is not driven (stopped), the stop mode is M0, and the key position is switched off (or the handle is locked).
At this time, the cylinder deactivation mechanism 80 is deactivated, and the throttle valves 63-1 and 63-4 (first system), the throttle valve 63-2 (second system), and the throttle valve 63-3 (first system). The three target throttle openings 63-1 to 63-4 have the same target opening.
In the stop mode M0, when the main switch is operated and the key position is switched on (= IGP on), the state transits to the standby mode M1. At this time, the cylinder deactivation mechanism 80 is deactivated, and the throttle valves 63-1 and 63-4 (first system), the throttle valve 63-2 (second system), and the throttle valve 63-3 (first system). The three target throttle openings 63-1 to 63-4 have the same target opening.

In the standby mode M1, when the main switch is operated and the key position is turned on, when the engine is cold-started, the mode is always changed to the 4-cylinder mode M2 before warming up. This always-four-cylinder mode M2 before warm-up is a mode in which the transition is made when the oil temperature detected by the oil temperature sensor 99 is less than 40 ° C. At this time, the cylinder deactivation mechanism 80 is set in a non-operating state, Throttle valves 63-1 and 63-4 (first system), throttle valve 63-2 (second system), and throttle valve 63-3 (third system), three systems of throttle valves 63-1 to 63-3. No.-4 has the same target opening.
When the oil temperature detected by the oil temperature sensor 99 is 40 ° C. or higher in the constant four-cylinder mode M2, the mode is changed to the normal operation mode M3.

Further, in the standby mode M1, when the main switch is operated and the key position is turned on, the transition to the normal operation mode M3 occurs when the warm-up is started.
The normal operation mode M3 is roughly divided into a four-cylinder mode M31 that is always warmed up and a variable cylinder mode M32 that can automatically change the number of operating cylinders. Then, any mode is exclusively selected by the user selecting in advance with a predetermined changeover switch.

  The always-four-cylinder mode M31 after the warm-up is a mode when the oil temperature detected by the oil temperature sensor 99 is 40 ° C. or higher. At this time, the cylinder deactivation mechanism 80 is deactivated, and the throttle valve Three systems of throttle valves 63-1 to 63-4, 63-1 and 63-4 (first system), throttle valve 63-2 (second system), and throttle valve 63-3 (third system). Have the same target opening.

  On the other hand, the variable cylinder mode M32 is a mode in which the number of operating cylinders is changed according to the magnitude of the load, the engine speed, the vehicle speed, and the like. At this time, the cylinder deactivation mechanism 80 is in an operating state and a non-operating state. Any one is selected, and throttles of three systems of throttle valves 63-1, 63-4 (first system), throttle valve 63-2 (second system) and throttle valve 63-3 (third system) are selected. The target openings of the valves 63-1 to 63-4 are calculated individually for each system. Further, fuel injection is stopped in the cylinders that are deactivated. Further, an indicator (not shown) notifies the rider that the variable cylinder mode M32 is selected.

  Further, the variable cylinder mode M32 is a four-cylinder mode (first speed / 2-speed) M321 in which all of the first cylinder C1 to the fourth cylinder C4 are operating cylinders from the low load side to the high load side, the first cylinder. A two-cylinder mode M322 in which C1 and the fourth cylinder C4 are operating cylinders, a first cylinder C1 and a fourth cylinder C4, and a three-cylinder mode M323 in which either the second cylinder C2 or the third cylinder C3 is an operating cylinder; There are four cylinder modes, a four-cylinder mode M324, in which all of the first cylinder C1 to the fourth cylinder C4 are operating cylinders.

FIG. 12 is an explanatory diagram of the engine operating state corresponding to the output and the vehicle speed.
Specifically, as shown in FIG. 12, when the vertical axis is the output (kW) and the horizontal axis is the vehicle speed (km / h), in the area AR4X of low output (low load) and low vehicle speed, 4 The cylinder mode (first speed / 2 speed) M321 is set. In this area AR4X, the four cylinders C1 to C4 are used as operating cylinders. For example, in the area AR4X of low output (low load) and low vehicle speed, the second cylinder C2 and the third cylinder C3 are in a cylinder deactivation state. Then, the idle period of these cylinders C2 and C3 becomes longer, and so-called oil rise causes the lubricating oil to enter the combustion chambers of the second cylinder C2 and the third cylinder C3, and the second spark plug 71-2 or the third This is to prevent smoldering from adhering to the spark plug 71-3 and thus preventing this.
In this case, in the low output (low load) and low vehicle speed region AR4X, the four-cylinder mode (1st speed / 2nd speed) M321 is set, and after a predetermined time has elapsed since the start of operation of all the cylinders C1 to C4. It is also possible to deactivate some cylinders and shift to a later-described two-cylinder mode M322 or three-cylinder mode M323. By adopting such a configuration, the effective cylinder deactivation time can be shortened, and fuel consumption can be improved while preventing smoldering of the spark plug of the deactivation cylinder.

By the way, when the vehicle speed is equal to or lower than the predetermined value, cylinder deactivation (2-cylinder mode M322 or 3-cylinder mode M323, which will be described later) is stopped and all cylinders (C1 to C4) are operated cylinders (1-speed / 2). When shifting to (speed) M321, the shift is made when the vehicle speed is equal to or lower than a predetermined value. This predetermined value is set higher as the output increases.
Specifically, when the output is L1, when the vehicle speed becomes V1 or less, the mode shifts to the 4-cylinder mode (1st speed / 2nd speed) M321, but when the output is L2 (> L1), the vehicle speed If it becomes V2 (> V1) or less, it will shift to 4 cylinder mode (1st speed / 2 speed) M321.

That is, the predetermined value (predetermined vehicle speed value) with all the cylinders C1 to C4 as operating cylinders is set higher as the output of the internal combustion engine becomes higher.
Further, in the low output and medium vehicle speed region AR2, the two-cylinder mode M322 is set. Accordingly, since the second cylinder C2 and the third cylinder C3 are deactivated cylinders, the fuel consumed in these two cylinders can be reduced, and the fuel consumption can be improved.

Further, in the medium output and medium vehicle speed region AR3, the three-cylinder mode M323 is set. As a result, since either the second cylinder C2 or the third cylinder C3 is a deactivated cylinder, the fuel consumed in either one of the cylinders can be reduced, and the fuel efficiency can be improved.
Further, in the high output or high vehicle speed area AR4, the four-cylinder mode M324 is set.
Actually, the ECU 76 stores the map shown in FIG. 12, and according to the current output and vehicle speed, the four-cylinder mode (first / second speed) M321, the two-cylinder mode M322, the three-cylinder mode M323 or Of the four-cylinder mode M324, the operation is performed in an optimum mode.

Further, in the normal operation mode M3, when an abnormality is detected in the second cylinder C2 or the third cylinder C3 that performs cylinder deactivation and it is determined that the cylinder deactivation cannot be performed normally, a transition is made to the fail mode M4.
That is, in the normal operation mode M3, when the second intake pressure sensor 97-2 or the third intake pressure sensor 97-3 detects an abnormality in the intake pressure, the second hydraulic sensor is 100-2 or the third hydraulic sensor 100-. 3 when a pressure abnormality is detected, or when an abnormality is detected in either the throttle valve 63-2 (second system) or the throttle valve 63-3 (third system). The process shifts to M4 and always operates in the two-cylinder mode (the first cylinder C1 and the fourth cylinder C4 are always operated). This is because it is not possible to guarantee that the second cylinder C2 and the third cylinder C3 that can perform cylinder deactivation are normally operated. Therefore, only the first cylinder C1 and the fourth cylinder C4 that can be reliably operated are operated as fail-safe. It is.

  As described above, according to the present embodiment, the cylinder is stopped for a long time when the internal combustion engine, which is an engine, is operated at a low load and a low rotational speed, and the lubricating oil that has entered the combustion chamber due to so-called oil rise adheres to the spark plug. This can prevent the spark plug from smoldering.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 10 Valve operating apparatus 11 Intake valve 12 Exhaust valve 20 Combustion chamber 70-1 to 70-4 1st injector-4th injector 71-1-71-4 1st spark plug-4th spark plug 72 Oil path 73 74 Control oil passage 75a First spool valve 75b Second spool valve 76 ECU
80 cylinder deactivation mechanism 97-1 to 97-3 first intake pressure sensor to third intake pressure sensor 99 oil temperature sensor 100-1 to 100-3 first hydraulic pressure sensor to third hydraulic pressure sensor 110 motorcycle (vehicle)
C1 to C4 1st cylinder to 4th cylinder M0 Stop mode M1 Standby mode M2 Always 4 cylinder mode M3 Normal operation mode M4 Fail mode M31 Always 4 cylinder mode M32 Variable cylinder mode M321 4 cylinder mode (1st speed / 2nd speed)
M322 Two-cylinder mode M323 Three-cylinder mode M324 Four-cylinder mode Vsw Switching hydraulic pressure

Claims (4)

In the multi-cylinder internal combustion engine (10) including a cylinder deactivation mechanism (80) that deactivates the cylinder by maintaining the intake valve (11) and the exhaust valve (12) in a closed state.
Before starting the transition from the operating state in which the intake valve (11) and the exhaust valve (12) are opened to the closed rest state, the fuel injection of the cylinder to be stopped is stopped, and the ignition plug of the cylinder to be stopped And stop the energization of the air, and open the intake valve (11) and perform an air cycle for gas exchange to replace the gas in the combustion chamber (20-2, 20-3),
The fuel injection stop instruction is performed after injecting fuel in the intake stroke of the four-cycle period immediately before the period corresponding to the air cycle and before the intake stroke in the period corresponding to the air cycle,
The start of the stop of the fuel injection is before the intake stroke of at least one cycle before the cycle of four cycles for shifting the cylinder to the stop, and after the fuel injection timing at which the fuel burned last is injected Cylinder deactivation,
Further, before the intake valve (11) and the exhaust valve (12) complete the transition from the rest state to the operating state, the fuel injection and ignition of the spark plug are not performed, and the intake valve (11 ) And the exhaust valve (12) to start operation, the cylinder operation after the cylinder deactivation in which the exhaust valve (12) starts to operate first,
Select稼dynamic cylinder number capable of changing a variable cylinder mode, with a portion of the cylinder is at rest, stop cylinder deactivation at low load and low rotational speed, operating cylinders and all the cylinders (C1 -C4) A multi-cylinder internal combustion engine comprising a cylinder deactivation mechanism. In the multi-cylinder internal combustion engine (10) including a cylinder deactivation mechanism (80) that deactivates the cylinder by maintaining the intake valve (11) and the exhaust valve (12) in a closed state.
The multi-cylinder internal combustion engine is mounted on a vehicle (110),
Before starting the transition from the operating state in which the intake valve (11) and the exhaust valve (12) are opened to the closed rest state, the fuel injection of the cylinder to be stopped is stopped, and the ignition plug of the cylinder to be stopped And stop the energization of the air, and open the intake valve (11) and perform an air cycle for gas exchange to replace the gas in the combustion chamber (20-2, 20-3),
The fuel injection stop instruction is performed after injecting fuel in the intake stroke of the four-cycle period immediately before the period corresponding to the air cycle and before the intake stroke in the period corresponding to the air cycle,
The start of the stop of the fuel injection is at least before the intake stroke of one cycle before the cycle of four cycles to shift to cylinder deactivation, and after the fuel injection timing at which the fuel burned last is injected Cylinder deactivation,
Further, before the intake valve (11) and the exhaust valve (12) complete the transition from the rest state to the operating state, the fuel injection and ignition of the spark plug are not performed, and the intake valve (11 ) And the exhaust valve (12) to start operation, the cylinder operation after the cylinder deactivation in which the exhaust valve (12) starts to operate first,
Select稼dynamic cylinder number capable of changing a variable cylinder mode, with a portion of the cylinder is at rest, when the speed of the vehicle is less than a predetermined value, stop cylinder deactivation, all the cylinders (C1 A multi-cylinder internal combustion engine provided with a cylinder deactivation mechanism characterized in that C4) is an active cylinder.   The multi-cylinder internal combustion engine having a cylinder deactivation mechanism according to claim 2, wherein the predetermined value with all cylinders as operating cylinders is set higher as the output of the multi-cylinder internal combustion engine increases. 4. The operation according to claim 1, wherein all cylinders are operated as operating cylinders at low load and low rotation, and some cylinders are deactivated after a lapse of a predetermined time from the start of cylinder operation. A multi-cylinder internal combustion engine comprising the cylinder deactivation mechanism according to any one of the above .

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