JPH05231212A - Intake air quantity control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate any difference in torque stage at the time of changeover of engine operation by increasing the quantity of intake air under the operation state of recirculating exhaust gas and compensating, with the increased torque the difference between the torque generated when recirculation of exhaust gas is performed and that generated when it is not performed respectively. CONSTITUTION:An internal combustion engine 9 is equipped with a helical passage 3, which is connected to an intake pipe 1 and helically laid around the opening end of a combustion chamber 2, and a straight passage 4 which is connected straightly to the same opening end. A first operation state 7, in which an intake control valve 5 in the straight passage 4 is closed and an exhaust gas recirculating device 6 is operated and a second operation state 8, in which the intake control valve 5 is opened and the exhaust gas recirculating device 6 is stopped, are switched by means of a changeover means 10. In this case, the intake air quantity is increased by means of a means 11 during the first operation state 7 and the torque difference between respective generated torques of the first and the second operation states 7, 8 is compensated with the torque that is caused by increased quantity of intake air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air amount control system for an internal combustion engine, and more particularly to a helical passage for forming a spiral intake air flow in a combustion chamber and exhaust gas recirculation by introducing the exhaust gas into an intake pipe. Exhaust Gas Recirculation (hereinafter referred to as EGR)
And an exhaust gas recirculation device for performing an intake air amount control device for an internal combustion engine.

[0002]

2. Description of the Related Art As one of the intake port structures of a variable intake swirl system used in an internal combustion engine, there is provided a helical passage swirling around an opening end of a combustion chamber and a straight passage communicating with the opening end in a straight line. An intake port structure is generally known in which an intake control valve that opens and closes the straight passage is provided in the middle of the straight passage. In an internal combustion engine equipped with this intake port structure, when the straight passage is closed by the intake control valve, all of the intake air (mixture) flows through the helical passage and flows into the combustion chamber, so that strong intake air is introduced into the combustion chamber. A swirl is generated, which increases the combustion speed and enables the operation with the lean air-fuel mixture and the operation with the EGR. The rapid combustion by the intake swirl is particularly effective in the low load region.

On the other hand, it has a communication passage communicating from the exhaust pipe to the intake pipe, and an exhaust gas recirculation valve (EGR valve) for adjusting the passage area of this communication passage. The exhaust gas is introduced into the intake pipe and exhausted. Exhaust gas recirculation device (E
GR device) is known. In this EGR device, the maximum combustion temperature is lowered by mixing the exhaust gas (inert gas) into the intake air, and the generation amount of nitrogen oxides (NOx), which has the characteristic that the generation amount increases and decreases depending on the maximum combustion temperature, is controlled. It is decreasing. In addition, since the throttle valve is opened to maintain the previous output as much as the output is reduced due to the introduction of exhaust gas, pumping loss in the intake stroke is reduced, especially in the low load range, and fuel efficiency is improved accordingly. ..

When the lean air-fuel mixture is rapidly burned by the intake swirl, the amount of NOx generated increases, the amount of NOx released into the atmosphere increases, and exhaust emission deteriorates. Therefore, when the rapid combustion by the intake swirl is performed in the low load region, the EGR is also executed to suppress the NOx generation amount at this time to prevent the deterioration of the exhaust emission and improve the fuel efficiency as described above. The operation that was made to happen is being performed. Further, in the high load region, since the effect of the intake swirl is reduced and a high output is required, a normal operation is performed in which both the rapid combustion due to the intake swirl and the above EGR accompanied by a decrease in output are stopped.

As described above, the operating state in the low load region in which the rapid combustion by the intake swirl and EGR are executed together and the high load region in which the normal operation is performed without executing both the rapid combustion by the intake swirl and EGR are performed. It has been well known that a control method capable of improving exhaust emission and fuel efficiency and obtaining a desired high output in a high load range by switching an operating state according to a load range of an internal combustion engine. (JP-A-59-49359).

[0006]

FIG. 10 shows the relationship between the throttle opening (TA) and the generated torque (T) for EGR execution /
It is a figure represented in both conditions of stop. As shown in the figure, since the exhaust gas is mixed into the intake air when the EGR is being executed, the generated torque is lower than that when the EGR is stopped even when the throttle opening is the same. Therefore, in the above conventional control method, as shown in FIG. 11, EGR is executed in the low load range up to the throttle opening TA ₁ (however, except in the idle operation state), and therefore the dotted line in FIG. In the operating state where the generated torque is low corresponding to the curve shown by (curve D), and EGR is stopped in the high load range of the throttle opening TA ₁ or more, the curve shown by the solid line in FIG. A corresponding operating state with high generated torque is achieved (curve E). Therefore, when the accelerator pedal is depressed to open the throttle opening, as shown in FIG. 11, when passing through the throttle opening TA _{1 at} which the operating state in the low load range and the operating state in the high load range are switched. There is a problem that a torque step occurs and drivability deteriorates. Even when the throttle opening is closed, an opposite torque step is generated when passing through a throttle opening TA ₂ set apart from TA ₁ to prevent hunting as shown in FIG. ..

Therefore, the present invention has been made in view of the above problems. In the operating state of the low load region, the intake air amount is increased to compensate for the torque decrease due to the execution of EGR. An object of the present invention is to provide an intake air amount control device for an internal combustion engine, which prevents a torque step when the operating state of the load range is switched.

[0008]

FIG. 1 is a block diagram showing the principle of the present invention for achieving the above object. As shown in the figure, according to the present invention, the helical passage 3 communicating with the intake pipe 1 and swirling around the opening end to the combustion chamber 2 is communicated with the intake pipe 1, and communicates with the opening end linearly. A straight passage 4, an intake control valve 5 that opens and closes the straight passage 4, and an exhaust gas recirculation device 6 that introduces exhaust gas into the intake pipe 1 to recirculate the exhaust gas are provided. The first operating state 7 in which the valve 5 is closed and the exhaust gas recirculation device 6 recirculates the exhaust gas, and the intake control valve 5 is opened, and the recirculation of the exhaust gas is stopped. In the intake air amount control device for an internal combustion engine, the intake air amount control device having a switching means 10 for switching between the second operating state 8 and the second operating state 8 according to the operating state of the internal combustion engine 9. The intake air amount increasing means 11 for increasing the The torque difference between the generated torque in the torque generated second operational state 8 in operating state 7, it is configured to compensate a torque component generated by the increase of the intake air amount by the intake air amount increasing means 11.

[0009]

In the first operating state 7 in which the intake control valve 5 is closed and the exhaust gas recirculation device 6 is recirculating the exhaust gas, the intake control valve 5 is opened and the exhaust gas is exhausted. The generated torque is lower than in the second operating state 8 when the gas recirculation is stopped. Therefore, in the present invention, the intake air amount increasing means 11 increases the intake air amount in the first operating state 7, whereby the intake air amount is increased and fuel is additionally injected to generate new torque. .. Then, the torque difference between the generated torque in the first operating state 7 and the generated torque in the second operating state 8 is compensated by the newly generated torque. As a result, the first operating state 7
The torque difference between the second operating state 8 and the second operating state 8,
The torque step when switching between the operating state 7 and the second operating state 8 is eliminated.

[0010]

FIG. 2 is a schematic configuration diagram showing one embodiment of an internal combustion engine and peripheral devices in which the intake air amount control device for an internal combustion engine according to the present invention is implemented, and FIG. 3 is a schematic diagram of the internal combustion engine shown in FIG. It is a schematic block diagram which shows an intake port structure.

In these drawings, reference numeral 21 denotes an internal combustion engine, which has a cylinder block 22 and a cylinder head 23. The cylinder block 22 has a piston 24 in a cylinder bore formed therein. And a combustion chamber 25 is formed above the piston 24 in cooperation with the cylinder head 23. An intake port 26 and an exhaust port 27 are formed in the cylinder head 23, respectively, and these ports are opened and closed by an intake valve 28 and an exhaust valve 29 at the open ends to the combustion chamber 25, respectively. In addition, the cylinder head 23
A spark plug 30 is attached to the.

The intake port 26 has a helical passage 32 which is swiveled around an opening end to the combustion chamber 25 which is divided by a guide vane 31, and a straight passage 33 which linearly communicates with the opening end. An intake control valve 34 is provided in the middle of the straight passage 33.
Is configured as a butterfly valve carried on the valve shaft 35,
The straight passage 33 is opened and closed.

If a more detailed description of this intake port structure is required, Japanese Patent Application No. 56-120634 can be used.
And Japanese Patent Application No. 57-79459.

An intake manifold 36 corresponding to the intake pipe 1 is connected to the intake port 26, and a fuel supply device 37 is connected to the intake manifold 36. The fuel supply device 37 includes a fuel injection valve 38 and a throttle valve 39.

A drive lever 45 is attached to a valve shaft 35 of the intake control valve 34, and the drive lever 45 is drivingly connected to a rod 47 of a diaphragm device 46. The diaphragm device 46 brings the intake control valve 34 to the fully open position as shown in FIG. 3 when the negative pressure is not introduced into the diaphragm chamber, whereas the negative pressure is introduced when the negative pressure is introduced into the diaphragm chamber. The control valve 34 is brought to a fully closed position which is rotated by about 90 ° from the fully open position.

The diaphragm chamber of the diaphragm device 46 is connected to the port a of the electromagnetic switching valve 49 via the conduit 48. The electromagnetic switching valve 49 has a negative pressure port b and an atmospheric pressure port c in addition to the port a, and connects the port a to the negative pressure port b when energized and connects the port a to the atmospheric pressure port c when de-energized. It has become. The negative pressure port b is connected to the intake manifold 3 via the conduit 50, the check valve 51, and the conduit 52.
6 is connected to the intake pipe negative pressure extraction port 53. Energization of the electromagnetic switching valve 49 is performed by the control device 70 described later.

The exhaust port 27 has an exhaust manifold 4 at the exhaust port 27.
0, a maniverter 41, an exhaust pipe 42, a three-way catalytic converter 43, and an exhaust pipe 44 are sequentially connected. The exhaust manifold 40 is an exhaust gas extraction port 5 for exhaust gas recirculation.
4 is provided, and this port is connected to an exhaust gas injection port 59 provided in the intake manifold 36 through a conduit 55, a flow rate control device 56, and a conduit 58. The flow rate control device 56 includes an exhaust gas recirculation control valve (EGR valve) 60 and a negative pressure adjustment valve 61, and the intake pipe negative pressure extraction port 6 provided in the fuel supply device 37 as control fluid pressure.
The negative pressure of the intake pipe appearing at 2 is selectively applied through the conduit 63, the electromagnetic opening / closing valve 64 and the conduit 65, and the exhaust gas recirculation flow rate is controlled in a back pressure control manner according to the intake air amount. ..

The solenoid opening / closing valve 64 is connected to the conduits 63 and 6 only when energized.
5 are connected to each other, and the energization control for them is performed by the control device 70. Therefore, EGR
The valve 60, the negative pressure adjusting valve 61, main parts such as the conduits 55 and 58, and other hardware structure for opening and closing the EGR valve 61, and the electromagnetic opening and closing valve 64 performed in the control device 70. The exhaust gas recirculation device 6 is configured by software processing.

An intake bypass inlet port 81 is provided upstream of the throttle valve 39 in the fuel supply device 37.
This port is equipped with a conduit 82 and an idle speed control valve (IS
It is connected via a CV) 83 and a conduit 84 to an intake bypass outlet port 85 provided on the downstream side of the throttle valve 39. The ISCV 83 is an electromagnetic flow rate adjusting valve that adjusts the passage area of the conduits 82 and 84, and the controller 70
An appropriate opening degree is set by a pulse signal with an appropriate duty ratio from the control valve, and the flow rate of intake air (mixture) flowing from the upstream side of the throttle valve 39 to the downstream side by bypassing the throttle valve 39 is controlled. ing. According to this ISCV83, for example, when an auxiliary device driven by the internal combustion engine 21 such as an air conditioner (not shown) is operated during idle operation, the ISCV83 is opened by an appropriate amount, and the intake air amount It is possible to increase the amount of fuel injection and generate new torque to prevent the idle speed of the internal combustion engine 21 from dropping.

Further, in FIG. 2, 71 is provided in a distributor (not shown), a rotation angle sensor for outputting a signal according to the engine speed, and 72 is an intake manifold 36.
A pressure sensor for detecting the negative pressure inside, 73 for a throttle position sensor for detecting the opening of the throttle valve 39,
74 is an oxygen sensor for detecting the oxygen concentration in the exhaust gas, and 75 is a water temperature sensor for detecting the engine cooling water temperature.

Next, FIG. 4 shows specific components of the control device 70. 2, those parts which are the same as those corresponding parts in FIG. 2 are designated by the same reference numerals, and a description thereof will be omitted. In the figure, a central processing unit (CPU) 80 inputs and calculates data output from each sensor in accordance with a control program and controls various actuators such as the fuel injection valve 38, ISCV 83, and electromagnetic switching valve 49. It is designed to process. A read only memory (ROM) 81 is a storage device that stores data such as the control program and the ignition timing calculation map, and is a random access memory (RAM).
Reference numeral 82 denotes a storage device that temporarily reads and writes data output from each sensor and data necessary for arithmetic control, and includes a backup random access memory (backup RA).
M) 83 is a storage device in which data or the like necessary for driving the engine is backed up by a battery power source even when an ignition switch (not shown) is turned off.

The input section 84 shapes the output signals of the sensors such as the pressure sensor 72 and the oxygen sensor 74 by a waveform shaping circuit (not shown) and selectively outputs the signals to the CPU 80 by a multiplexer (not shown). There is. In the input section 84, if the output signal from each sensor is an analog signal, it is converted into a digital signal by the A / D converter 86. The input / output unit 85 waveform-shapes the output signal of the rotation angle sensor 71 or the like, which is the basis of the engine speed signal, by the waveform shaping circuit, and writes this signal in the RAM 82 or the like via the input port. The input / output unit 85 is a CP
The fuel injection valve 38, the ISCV 83, and the electromagnetic switching valve 4 are driven by a drive circuit that is driven via the output port in response to a command from U80
9 and the like are driven at a predetermined timing. Bus line 87
Is an A / D converter 86 connected to each element such as the CPU 80 and the ROM 81 and the input section 84, and the input / output section 8
5 is connected to send various data.

The CPU 80 in the control device 70 having the above-mentioned configuration
Inputs the detection signals from the various sensors 71 to 75, and according to a program stored in the ROM 81, the valve opening time (fuel injection amount) of the fuel injection valve 38 and the electromagnetic switching valve 4
The energization of the solenoid valve 9 and the solenoid opening / closing valve 64 is controlled as described below, and the opening degree of the ISCV 83 is controlled according to a flowchart described later with reference to FIG.

First, the throttle position sensor 7 controls the fuel injection amount corresponding to the opening time of the fuel injection valve 38.
In an idle operation state, an acceleration operation state, and a high load operation state in which a predetermined output or more is determined based on the output signal of the throttle opening detected by No. 3, the output signal of the engine speed by the rotation angle sensor 71 and the pressure sensor. 72
Signal relating to the engine load calculated by the negative pressure output signal in the intake manifold 36 by the
Based on the signal of the oxygen concentration in the exhaust gas detected by the engine, a mixture of stoichiometric air-fuel ratio is supplied to the internal combustion engine 21. Further, in the low load operation state of the predetermined output or less except for the idle operation state, the lean air-fuel mixture having an air-fuel ratio (lean) larger than the theoretical air-fuel ratio is supplied to the internal combustion engine 21. Here, the predetermined outputs for partitioning the high load operating state and the low load operating state in the present embodiment are TA ₁ and TA ₂ indicated by the throttle opening degree described above in FIG. 11.

Although the control device 70 also controls the injection timing of the fuel injection valve 38, a description thereof will be omitted here.

The electromagnetic switching valve 49 is energized only in the low load operating state in which the lean air-fuel mixture is supplied as described above. That is, in the low load operation state, the electromagnetic switching valve 49 is energized and the intake control valve 34 is closed as described above.

The electromagnetic opening / closing valve 64 is energized only when the water temperature detected by the water temperature sensor 75 has a predetermined value, for example, 20 ° C. or higher and the electromagnetic switching valve 49 is energized. .. That is, when the cooling water temperature is equal to or higher than a certain temperature and is in the low load operation state, the electromagnetic opening / closing valve 64 is energized to execute the EGR as described above.

Therefore, when the internal combustion engine 21 is operating under a low load, the intake control valve 34 in the straight passage 33 is closed and all the intake air flows through the helical passage 32, so that a strong intake swirl is generated in the combustion chamber 25. As a result, rapid combustion of the lean air-fuel mixture is enabled, and in addition, the EGR valve 60 is opened and EGR is executed, so that the generation of NOx is suppressed even during the combustion of the lean air-fuel mixture. On the contrary, in the high load operation state of the internal combustion engine 21, the intake control valve 34 is opened and the EGR valve 60 is closed, so that the EGR accompanying the output reduction of the engine is not performed and a desired high output is obtained. Obtainable. In the idle operation state, the acceleration operation state, and the high load operation state in which the lean air-fuel mixture is not rapidly burned, the three-way catalytic converter 43 is supplied because the air-fuel mixture having the stoichiometric air-fuel ratio is supplied as described above.
Effectively operates to purify NOx, and a large amount of NOx is prevented from being discharged into the atmosphere even if EGR is not executed as in the low load operation state.

As described above, in the present embodiment, the low load operating state partitioned by the throttle openings TA ₁ and TA ₂ corresponds to the first operating state 7, and the high load operating state corresponds to the second operating state. Equivalent to 8.

Next, a method of controlling the opening of the ISCV 83 will be described.

FIG. 5 shows a flow chart of an ISCV control routine as a control program constituting a main part of an embodiment of the device of the present invention. In addition to the hardware configuration of the ISCV 83 and the conduits 82 and 84 shown in FIG.
The PU 80 executes the software process of the flowchart shown in FIG. 5 to execute the intake air amount increasing means 1 described above.
Achieve 1.

In FIG. 5, when the ISCV control routine is activated by interruption every predetermined time, first, at step 102, it is judged if the intake control valve 34 is in the closed state, that is, the EGR execution state. When the intake control valve 34 is in the closed state, that is, in the completely closed state or in the middle of the closing operation, it means that the throttle opening is TA ₁ (TA ₂ ) or less in the low load operation state. Go to step 104 of. In step 104, the count-up timer Co when the intake control valve 34 is opened is prepared for the processing of step 116 described later.
reset p. The count-up timer Cop is a timer that counts up from the time when the valve opening operation of opening the intake control valve 34 starts from 0 (zero).

In the next step 106, the intake control valve 34
The count-up timer Ccl when the valve is closed and the intake control valve 3
4 is compared with the time Kcl (constant) required to close the valve from open to closed. Contrary to the count-up timer Cop, the count-up timer Ccl is set to 0 when the valve closing operation for closing the intake control valve 34 from open to closed is started.
The timer is counted up from that point as (zero), and is reset in advance at step 114 when the intake control valve 34 is opened. Therefore, step 10
When the value of the timer Ccl is less than the above Kcl in (6) (Ccl <Kcl), it means that the intake control valve 34 is in the middle of the valve closing operation from open to closed (half-open state),
When the value of Ccl is Kcl or more (Ccl ≧ Kc
1) means that the valve closing operation is completed and the intake control valve 34 is completely closed.

When the intake control valve 34 is in the process of closing, the valve opening Yb of the ISCV 83 is calculated in step 108, and when it is in the completely closed state, in step 110 the valve opening Yb of the ISCV 83 is calculated. Calculate Yb.

On the other hand, at step 102, the intake control valve 34
Is in the valve open state, that is, in the complete valve open state or in the middle of the valve opening operation, it means that the throttle opening is under high load operation of TA ₁ (TA ₂ ) or more.
Proceed to. In step 114, the intake control valve 34 described above is used.
Intake control valve 3 in preparation for the processing when closing the valve (step 106)
4 Reset the count-up timer Ccl when the valve is closed.

In the next step 116, the count-up timer Cop when the intake control valve 34 is opened is compared with the time Kop (constant) required for the intake control 34 to open from closed to open. Here, the count-up timer Cop is continuously reset in the above step 104 when the valve is closed (during valve closing operation or in a completely closed state), and the valve opening operation is started and “NO” is selected in step 102. At the same time, since the count-up is started, the elapsed time of the opening operation of the intake control valve 34 is accurately counted (the same applies to Ccl). Therefore, when the value of the timer Cop is less than the above Kop in step 116 (Cop <Kop), it means that the intake control valve 34 is in the middle of the valve opening operation from the closed state to the open state (half-open state). , Cop is greater than or equal to Kop (Cop ≧ Ko
In p), it means that the valve opening operation is completed and the intake control valve 34 is in a completely opened state.

When the intake control valve 34 is in the middle of the valve opening operation, the valve opening degree Yb of the ISCV 83 is calculated in step 118, and when it is in the completely open state, the valve opening degree of the ISCV 83 is calculated in step 120. Calculate Yb.

As described above, the count-up timer Cc
It is possible to determine the states of the intake control valve 34 from open to closed, closed, closed to open, and open, from the values of l and Cop, and the valve opening Yb of the ISCV 83 in that state can be determined. It is calculated in any of steps 108, 110, 118 and 120.

When the driver of the vehicle is using the accelerator opening degree from the idle operation state to the throttle opening degree TA ₁ , the intake control valve 34 is in the completely closed state,
The valve opening Yb of the ISCV 83 is calculated by the following equation in step 110.

Yb = Y (TA) + Y (THWcl) (1) In the above formula (1), Y (TA) corresponds to the warmth and the throttle opening (TA) when the intake control valve 34 is closed. ISCV
Indicates the opening degree of 83. This Y (TA) can be obtained from the map of the throttle opening (TA) and the ISCV opening shown in FIG. 6 by reading the output signal (throttle opening) of the throttle position sensor 73. In FIG. 6, the opening of the ISCV 83 from the idle operation state to the throttle opening TA ₁ is obtained corresponding to the curve A from P ₀ to P ₁ in the map. Also, in the above formula (1), Y
(THWcl) is the ISC when the intake control valve 34 is closed
The water temperature correction amount of the opening of V83 is shown. This Y (THWc
l) can be obtained by reading the output signal of the water temperature sensor 75 and using the map shown in FIG.

Next, when the driver depresses the accelerator pedal to make the throttle opening larger than the throttle opening TA ₁ , the above-mentioned electromagnetic switching valve 4 of the control unit 70.
9. The intake control valve 34 is controlled by controlling the electromagnetic opening / closing valve 64.
And the EGR is stopped. Here, during the opening operation of the intake control valve 34, the valve opening degree Yb of the ISCV 83 is calculated by the following equation shown in step 118.

Yb = (1−Cop / Kop) × {Y (TA) + Y (THWcl) −Y (THWop)} + Y (THWop) (2) Further, when the intake control valve 34 is completely open. The valve opening Yb is calculated by the following equation shown in step 120.

Yb = Y (THWop) (3) In the above equations (2) and (3), Y (THWop) represents the water temperature correction amount of the opening of the ISCV 83 when the intake control valve 34 is opened, It is obtained from a map (not shown) according to the map shown in FIG. As can be seen from the above equation (3), when the intake control valve 34 is completely open, the valve opening Yb of the ISCV 83 is calculated regardless of the throttle opening. Therefore, in FIG. 6, the opening degree of the ISCV 83 with respect to the throttle opening degree larger than TA ₁ is set to 0 (zero).

Since Cop = 0 at the start of the valve opening operation in which the intake control valve 34 is in the completely closed state, the above equation (2) becomes Yb = Y (TA) + Y (THWcl), and intake control is performed. The equation is the same as the above equation (1) when the valve 34 is closed. Further, since Cop = Kop at the completion of the valve opening operation in which the intake control valve 34 is in a completely open state, the above equation (2) becomes Yb = Y (THWop), and the intake control valve 34 is opened. The equation is the same as the above equation (3). As described above, according to the above equation (2), the intermediate opening degree between the valve opening degree of the ISCV 83 at the start of the valve opening operation of the intake control valve 34 and the valve opening degree of the ISCV 83 at the completion of the valve opening operation is given by: It can be obtained according to the value of the count-up timer Cop that indicates the elapsed time of the valve opening operation. That is, I obtained by the above equation (2)
The valve opening of SCV83 is the straight line B between P ₁ and P _{2 in} FIG.
This corresponds to the part (However, in FIG. 6, the water temperature correction is not added).

Next, when the driver releases the accelerator pedal to make the throttle opening smaller than the throttle opening TA ₂ (see FIG. 11), the control device 70 controls the intake control valve 34 to close. At the same time, EGR is executed. During the closing operation of the intake control valve 34, the valve opening Yb of the ISCV 83 is calculated by the following equation shown in step 108.

Yb = (Ccl / Kcl) × {Y (TA) + Y (THWcl) −Y (THWop)} + Y (THWop) (4) In addition, in the completely closed state, as shown in step 110, The valve opening Yb is calculated by the equation (1).

Here, the above equation (4) is, like the above equation (2), the ISCV at the start of the closing operation of the intake control valve 34.
83 valve opening and ISCV83 when the valve closing operation is completed
The intermediate opening degree between the valve opening degree and the valve opening degree is shown in correspondence with the count-up timer Ccl that indicates the elapsed time of the valve closing operation. That is, when Ccl = 0 is substituted in the above equation (4), the equation becomes the same as the above equation (3) when the intake control valve 34 is opened,
When Ccl = Kcl is substituted, the same equation as the above equation (1) when the intake control valve 34 is closed is obtained. That is, the valve opening of the ISCV 83 obtained from the above equation (4) corresponds to the portion of the dotted line C between P ₃ and P ₄ in FIG.

As described above, in the ISCV control routine shown in FIG. 5, in the low load operation state of the throttle opening TA ₁ (TA ₂ ) or less (corresponding to the first operation state), as shown in FIG. Therefore, the valve opening Yb of the ISCV 83 increases, and the amount of intake air taken by the internal combustion engine 21 increases in accordance with the value of the valve opening Yb. And, since the fuel injection amount also increases in response to the increase in the intake air amount,
The torque generated by the internal combustion engine 21 increases. Therefore, the above I
The SCV control routine is ISCV83 and conduits 82,8
4, the intake air amount increasing means 11 described above together with the hardware configuration of FIG.
To achieve.

Next, the effect of this embodiment will be described.

FIG. 8 is a diagram for explaining the effect of this embodiment. In the figure, the curves D and E and the straight line F are the same as the curves D and E and the straight line F of the generated torque with respect to the conventional throttle opening TA shown in FIG. Assuming now that the water temperature correction is not taken into consideration, the valve opening Y of the ISCV83
b is controlled as shown in FIG. 6 according to the throttle opening TA. Then, the valve opening degree Yb of the ISCV 83 shown in FIG.
Since the fuel is excessively injected due to the increase of the intake air amount in accordance with the above, the torque in the portion shown by hatching in FIG. 8 is newly generated and added to the generated torque shown by the conventional curve D.

Therefore, according to the control method of the ISCV 83 of the present embodiment, the torque component reduced by the intake control valve 34 being closed and the EGR being executed in the low load operating state of the conventional operating method is ISCV83. Compensates with the torque generated by opening the valve to increase the intake air amount. That is, the new curve G in which the torque generated by opening the ISCV83 is added to the conventional curve D, so that the new curve G shown in FIG. 10 coincides with the curve of the generated torque in the EGR stop state shown in FIG. Is set in advance.

[0052] Further, in the process of shifting the operation state of the internal combustion engine 21 from the low load operation state in which the boundary the throttle opening TA ₁ in the high-load operation state, the throttle opening in the conventional case shown in FIG. 11 TA ₁ When the generated torque rises stepwise when the temperature exceeds the
Is abruptly closed as indicated by the straight line B in FIG. 6, and the torque generated by the increase in the intake air amount is abruptly lost. Therefore, in this embodiment, the throttle opening is increased to change from the low load operating state to the high load operating state. The torque step does not occur in the process of shifting to. On the contrary, in the process of transitioning from the high load operating state to the low load operating state, the generated torque decreases stepwise when the throttle opening becomes smaller than TA _{2 in the} conventional case shown in FIG. ,
Since the ISCV 83 is suddenly opened as shown by the dotted line C in FIG. 6 and the generated torque is rapidly generated due to the increase of the intake air amount, in the present embodiment, the throttle opening is made small to change from the high load operating state to the low load. A torque step does not occur even in the process of shifting to the operating state.

As described above, according to the internal combustion engine 21 of this embodiment, the torque difference between the generated torque in the low load operating state and the generated torque in the high load operating state is ISCV.
Since the new torque generated by opening the valve 83 is completely compensated for, the torque generated with respect to the throttle opening TA matches the curve of the torque generated in the EGR stop state shown in FIG. It is represented by. That is, the generated torque continuously increases or decreases according to a series of throttle opening degrees that pass through the low load range and the high load range. as a result,
A throttle opening T for switching between opening and closing of the intake control valve 34 and execution / stop of EGR, which have occurred conventionally.
The torque difference between A ₁ and TA ₂ can be eliminated without lowering the torque, and thus the drivability can be improved as compared with the conventional case.

Further, the above-mentioned water temperature correction amount Y (THWc
As shown in FIG. 7, l) and Y (THWop) are corrected so that the ISCV 83 is opened as the cooling water temperature becomes higher. This is due to the following reason. In an internal combustion engine having an electronic fuel injection control device, in consideration of poor atomization of fuel when cold, as shown in FIG. 9, when the cooling water temperature is low, the warm-up increase of the fuel injection amount is increased. Implemented to set the air-fuel ratio to rich. Therefore, when the engine is cold, torque tends to be generated even when the throttle opening is the same as when it is warm. That is, it has two kinds of torque for a certain throttle opening. This is especially a problem in an automatic transmission in which the shift point and the line pressure of the transmission are determined by the throttle opening and the vehicle speed. That is, if the line pressure for clutch and brake of the transmission is set by adapting to the warm time when the torque is smaller than that in the cold state, the line pressure becomes insufficient in the cold state in which the torque tends to be generated, and the clutch and brake The slippage becomes large, which causes a problem in shifting feeling and durability. Further, since the shift-up point is also determined by the throttle opening, if the shift-up point is set in the warm state, there is a problem that the shift-up does not occur even though the torque is generated in the cold state and the rotation speed is increased.

Therefore, in the present embodiment, as shown in FIG. 7, the ISCV 83 is corrected to be opened as the cooling water temperature is higher, so that the intake air amount is increased and the generated torque is increased when the cooling water temperature is high. By increasing the temperature, it is possible to obtain the same level of generated torque even in the warm state as in the cold state in which the warm-up amount is increased. By performing the water temperature correction in this way, the generated torque is always determined to be 1: 1 with respect to the throttle opening regardless of whether it is cold or warm, and as a result, the above problems can be eliminated.

Further, in the prior art shown in FIG. 11, in order to prevent hunting of opening / closing of the intake control valve 34 and execution / stop of EGR in the vicinity of the throttle opening TA ₁ ,
Hysteresis is provided by the throttle openings TA ₁ and TA ₂ . Due to this hysteresis, between the throttle openings TA ₁ and TA _2, there are two generated torques for a certain throttle opening when the throttle opening is increasing and when it is decreasing. Therefore, in the past,
Not only in the cold or warm condition described above, but also between the throttle opening degrees TA ₁ and TA ₂ , the above-mentioned problems occur due to having two generated torques with respect to a certain throttle opening degree.

However, according to the present embodiment, the generated torque corresponding to the throttle opening is represented by one continuous curve shown by the curves G and E in FIG. 8 as described above. The generated torque corresponding to the throttle opening is determined on a one-to-one basis from the low load range to the high load range, and it is possible to eliminate the above-mentioned problems due to the conventional hysteresis.

In the above embodiment, the ISCV 83 was used as an example of the hardware configuration of the intake air increasing means 11, but the present invention is not limited to the above embodiment, and instead of the ISCV 83, for example, , Control device 70
The intake air amount may be increased by driving the throttle valve 39 to open in response to a signal from. Further, a dedicated bypass valve may be provided separately from the ISCV 83, and other configurations may be used.

Further, in the above-mentioned embodiment, the low-load operating state is set as the first operating state 7 and the high-load operating state is set as the second operating state 8, but the present invention is not limited to the above-mentioned example. However, the first and second operating states 7 and 8 may be set to any load range, and in this case as well, the transition between the first operating state 7 and the second operating state 8 is made. In this case, the torque step difference can be eliminated.

[0060]

As described above, according to the present invention, when the intake air amount increasing means increases the intake air amount in the first operating state, new torque is generated, and the generated torque in the first operating state is generated. In order to compensate the torque difference between the generated torque in the second operation state and the second operation state,
The torque difference between the first operating state and the second operating state disappears when the torque difference between the first and second operating states disappears.
The generated torque can be prevented without lowering. As a result, drivability can be improved as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a schematic configuration diagram showing one embodiment of an internal combustion engine and peripheral devices in which an intake air amount control device for an internal combustion engine according to the present invention is implemented.

3 is a schematic configuration diagram showing an intake port structure of the internal combustion engine shown in FIG.

FIG. 4 is a diagram showing specific components of the control device shown in FIG.

FIG. 5 is an ISC forming a main part of an embodiment of the device of the present invention.
It is a flowchart of a V control routine.

FIG. 6 is a diagram showing a map of throttle opening and ISCV opening.

FIG. 7 is a diagram showing a map of cooling water temperature and ISCV opening.

FIG. 8 is a diagram for explaining the effect of the present embodiment.

FIG. 9 is a diagram showing a relationship between cooling water temperature and air-fuel ratio.

FIG. 10 is a graph showing the relationship between throttle opening and generated torque.
It is a figure represented on both conditions of R execution / stop.

FIG. 11 is a diagram showing a relationship between a throttle opening and generated torque in a conventional device.

[Explanation of symbols]

1 Intake Pipe 2, 25 Combustion Chamber 3,32 Helical Passage 4,33 Straight Passage 5,34 Intake Control Valve 6 Exhaust Gas Recirculation Device 7 First Operating State 8 Second Operating State 9,21 Internal Combustion Engine 10 Switching Means 11 Intake air amount increasing means 26 Intake port 27 Exhaust port 28 Intake valve 31 Guide vane 36 Intake manifold 37 Fuel supply device 39 Throttle valve 49 Electromagnetic switching valve 60 Exhaust gas recirculation valve 64 Electromagnetic on-off valve 70 Control device 83 Idle speed control valve (ISC
V)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F02M 25/07 550 R 8923-3G

Claims (1)

[Claims] 1. A helical passage communicating with an intake pipe and swirling around an opening end to a combustion chamber; a straight passage communicating with the intake pipe and linearly communicating with the opening end; and opening and closing the straight passage. And an exhaust gas recirculation device that introduces exhaust gas into the intake pipe to recirculate the exhaust gas, closes the intake control valve, and uses the exhaust gas recirculation device. A first operating state in which exhaust gas recirculation is performed and a second operating state in which the intake control valve is opened and exhaust gas recirculation is stopped are switched according to the operating state of the internal combustion engine. In an intake air amount control device for an internal combustion engine, which comprises a switching means, an intake air amount increasing means for increasing the intake air amount in the first operating state is provided, and the generated torque in the first operating state and the In the second operating state The torque difference between the kicking generated torque, intake air quantity control apparatus for an internal combustion engine, characterized in that to compensate a torque component generated by the increase of the intake air amount by the intake air amount increasing means.