JP2015048740A - Control device for internal combustion engine, internal combustion engine and control method for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, the internal combustion engine and a control method for the internal combustion engine that enable reduction in fuel consumption on the basis of a vehicle state or a road state while easing the situation where a driver feels insufficient output of the internal combustion engine.SOLUTION: In addition to a normal torque curve 10 having a governing start point 12 for defining a governing start engine speed N1 on the basis of performance of an engine 1, a control device includes fuel-efficient torque curves 20, 30, 40 that have fuel-efficient governing start points 22, 32, 42 for defining fuel-efficient governing start engine speeds N2, N3, N4 each lower than the governing start engine speed N1, respectively and that are set to reduce fuel to be consumed more than that of the normal torque curve 10. The control device includes output control means M5 for controlling output of the engine 1 along at least one of the normal torque curve 10 and the fuel-efficient torque curves 20, 30, 40 selected based on at least either a vehicle state of a vehicle mounted with the engine 1 or a road state, during an operation of the engine 1.

Description

  The present invention relates to an internal combustion engine control device, an internal combustion engine, and an internal combustion engine control method, and more particularly to an internal combustion engine control device, an internal combustion engine, and an internal combustion engine control method capable of improving fuel efficiency.

  There has been proposed a device that automatically switches a plurality of engine torque curves (control performance lines) stored in a control device that controls the output of the engine based on a change in load capacity (see, for example, Patent Document 1). . This device improves fuel efficiency by automatically reducing the maximum output of the engine.

  However, in vehicles such as trucks that use a wide range of engine load conditions, from flat roads with light loads to uphill roads with heavy loads, due to the effects of vehicle running resistance due to weather such as road gradients and strong headwinds. There is a case where the output is limited excessively, and there is a problem that acceleration force and climbing force are reduced. On the other hand, there is a problem that fuel consumption is deteriorated due to excessive output.

JP 2006-226178 A

  The present invention has been made in view of the above-mentioned problems, and its problem is to reduce fuel consumption based on vehicle conditions and road conditions while alleviating the lack of output of the internal combustion engine felt by the driver. It is an object to provide a control device for an internal combustion engine, an internal combustion engine, and a control method for the internal combustion engine.

  The control apparatus for an internal combustion engine of the present invention for solving the above-described problems is based on the performance of the internal combustion engine as a control performance line indicating a torque generated with respect to the rotational speed of the internal combustion engine. In addition to the normal control performance line having a governing start point for defining the governing start rotational speed for starting suppression of the output of the internal combustion engine so as to suppress the torque generated with respect to the rotational speed, in addition to the governing start rotational speed One fuel efficiency control performance line that has a fuel efficiency governing start point that defines the fuel efficiency governing start speed with a low engine speed and that is set to reduce the amount of fuel consumed compared to the normal control performance line. When the internal combustion engine is operated, the normal control performance line selected based on at least one of a vehicle situation of a vehicle equipped with the internal combustion engine or a road situation; Serial along any one of a low fuel consumption control performance line, and an output control means for controlling an output of the internal combustion engine.

  The control performance line referred to here indicates the output state of the internal combustion engine, also called a performance curve or a torque curve, and the fuel injection amount and intake air are set so that the output is along the control performance line. The amount is determined.

  In addition, the governing start rotational speed referred to here is a rotation that starts controlling the output of the internal combustion engine so that the output torque of the internal combustion engine does not become high when the rotational speed of the internal combustion engine is in a high rotational speed range. Is a number. This governing start rotational speed becomes a standard for shifting the gear stage of the transmission while the vehicle is running.

  According to this configuration, by setting the low fuel consumption governing start rotational speed in the fuel efficiency control performance line to be lower than the governing start rotational speed in the normal control performance line, the rotational speed of the internal combustion engine in a region where the fuel consumption rate is low. Can be shifted early. As a result, the opportunity to operate the internal combustion engine in a region where the fuel consumption rate is low increases, and the fuel consumption can be reduced.

  In addition, by controlling the output of the internal combustion engine along a control performance line selected based on at least one of the vehicle situation or road situation of the vehicle, an optimum output is obtained for a wide range of operating conditions of the internal combustion engine. be able to. Thereby, fuel consumption can be reduced, relieving the output shortage of an internal combustion engine.

  Further, in the control device for an internal combustion engine, the normal control performance line is provided with a no-load maximum rotational speed point that defines a maximum rotational speed without load, and the low fuel consumption control performance line is provided with the low fuel efficiency control performance line. A low-speed, low-torque, low-torque, high-torque, low-torque route is provided at a lower torque than the fuel efficiency governing start point, and the low fuel efficiency control performance line starts the low fuel efficiency governing. From the point to the no-load maximum rotational speed point is bent at the via point, or is configured to pass through the via point while being curved, the maximum rotational speed of the internal combustion engine at the time of idling Even when the output is controlled along the performance line for low fuel consumption control, by making it the same as the no-load maximum rotation speed of the normal control performance line, when shifting while traveling or at high idle when filling the air tank, etc. Control discomfort Rukoto can.

  In addition, it is desirable that the via point is arranged on the origin side with respect to a straight line connecting the low fuel consumption governing start point and the no-load maximum rotational speed point.

  In addition, in the control device for an internal combustion engine, the normal control performance line is provided with a no-load maximum rotational speed point that defines a maximum rotational speed under no load, and the fuel efficiency control performance line is The low fuel consumption governing point is provided with a low torque, high rotational speed, higher torque than the no-load maximum rotational speed point, and a low rotation via point. When the shape from the start point to the via point is formed to be substantially the same as the shape from the governing start point of the normal control performance line to the no-load maximum rotational speed point, low fuel consumption The feeling of blasting from the starting speed of governing can be made the same as the feeling of blasting when controlled along the performance line for normal control, so the output is controlled along the performance line for fuel efficiency control. Even if It is possible to perform a shift operation in the same feeling as when it is controlled along the normal control performance line.

  Further, in the control device for an internal combustion engine, the performance line for normal control is formed so as to be able to output a maximum horsepower based on the performance of the internal combustion engine, and the performance line for fuel efficiency control is capable of being output. When the maximum horsepower is limited to a limited horsepower lower than the maximum horsepower, and is configured to be formed along an equal horsepower line of the limited horsepower as the rotational speed of the internal combustion engine increases from the limited horsepower, By limiting the maximum horsepower that can be output when the output of the internal combustion engine is controlled along the performance line for fuel efficiency control, it is possible to reduce the horsepower consumed by suppressing overspeed and reduce fuel consumption be able to.

Even when the fuel efficiency control performance line is used to control the output of the internal combustion engine, it is preferable to follow the normal control performance line up to the limit horsepower point that defines the limit horsepower. Therefore, for example, a fuel efficiency control performance line that shows the torque generated with respect to the rotational speed of the internal combustion engine from zero to the maximum rotational speed can reach the limit horsepower point as the rotational speed increases. Is usually formed along the performance line for control, and is formed along the equal horsepower line of the limited horsepower from the limited horsepower point. On the other hand, the one formed by branching a plurality of fuel efficiency control performance lines from one normal control performance line is branched from the normal control performance line to the equal horsepower line from the limit horsepower point that defines the limited horsepower. Formed along.

  In addition, in the control apparatus for an internal combustion engine, if the plurality of fuel efficiency control performance lines for reducing the fuel efficiency governing start rotational speed in stages are provided, for example, the power of the internal combustion engine When transmission is via a manual transmission, the respective fuel efficiency governing start speeds of the plurality of fuel efficiency control performance lines in which each consumed fuel is gradually decreased are set to be gradually decreased. As a result, the driver's gear shifting operation can be promoted at an early stage, and the rotational speed of the internal combustion engine can be maintained in a region where the fuel consumption rate is low.

  Alternatively, in the control device for an internal combustion engine, when the plurality of fuel efficiency control performance lines having the same fuel efficiency governing start rotational speed are provided, for example, the power transmission of the internal combustion engine is an automatic transmission. In this case, the speed of the internal combustion engine can be reduced by setting the fuel efficiency governing start rotational speeds of the plurality of fuel efficiency control performance lines at which the consumed fuel is lowered stepwise to the same rotational speed. It can be automatically maintained in a low fuel consumption area.

  And the internal combustion engine of this invention for solving said subject is comprised including the control apparatus of the internal combustion engine as described above. According to this configuration, it is possible to reduce fuel consumption while alleviating the feeling of insufficient output of the internal combustion engine that the driver feels.

  And the control method of the internal combustion engine of the present invention for solving the above problem is based on at least one of a vehicle situation of a vehicle equipped with the internal combustion engine or a road situation during operation of the internal combustion engine. A performance line for normal control having a governing start speed that defines the governing start speed based on the performance of the internal combustion engine, and a low fuel efficiency governing start that defines a low fuel efficiency governing start speed that is lower than the governing start speed. A point is selected, and one of the fuel efficiency control performance lines set so as to reduce the amount of fuel consumed than the normal control performance line is selected, and along the selected control performance line And controlling the output of the internal combustion engine.

  According to the control device for an internal combustion engine, the internal combustion engine, and the control method for an internal combustion engine of the present invention, the low fuel consumption governing start rotational speed in the fuel efficiency control performance line is set lower than the governing start rotational speed in the normal control performance line. By doing so, the rotational speed of the internal combustion engine can be shifted early to a region where the fuel consumption rate is low. As a result, the opportunity to operate the internal combustion engine in a region where the fuel consumption rate is low increases, and the fuel consumption can be reduced.

  In addition, by controlling the output of the internal combustion engine along a control performance line selected based on at least one of the vehicle situation or road situation of the vehicle, an optimum output is obtained for a wide range of operating conditions of the internal combustion engine. be able to. Thereby, fuel consumption can be reduced, relieving the output shortage of an internal combustion engine.

It is a figure which shows the structure of the control apparatus of the internal combustion engine and internal combustion engine of 1st embodiment which concerns on this invention. It is a figure which shows an example of the control map of the internal combustion engine of FIG. It is a figure which shows the performance line for fuel-efficient control of FIG. It is a figure which shows a part of control map of the internal combustion engine of FIG. It is a flowchart which shows the control method of the internal combustion engine of 1st embodiment which concerns on this invention. It is a figure which shows the structure of the control apparatus of the internal combustion engine and internal combustion engine of 2nd embodiment which concerns on this invention. It is a figure which shows an example of the control map of the internal combustion engine of FIG.

  Hereinafter, an internal combustion engine control device, an internal combustion engine, and an internal combustion engine control method according to embodiments of the present invention will be described.

  In FIGS. 1 and 6, the engine (internal combustion engine) 1 and 50 and the ECUs (control devices for internal combustion engine) 2 and 51 for controlling the engines 1 and 50 are mounted on the vehicle. Although described as a thing, it is not necessarily limited to what is mounted in a vehicle. Further, although the engines 1 and 50 are described as inline four-cylinder diesel engines, the present invention can also be applied to gasoline engines, and the number and arrangement of the cylinders are not particularly limited.

  In the following embodiment, the maximum horsepower that can be output from the engines 1 and 50 is distinguished from the maximum horsepower based on the performance of the engines 1 and 50, and the maximum horsepower based on the performance of the engines 1 and 50 is determined. The horsepower is the maximum horsepower P1. In addition, a torque curve (control performance line) used for actual control is distinguished by attaching a symbol TC.

  As shown in FIG. 1, in the vehicle equipped with the engine 1 and the ECU 2 of the first embodiment, the power of the engine 1 is transmitted to a manual transmission (manual transmission) 4 via a clutch 3. The transmission is transmitted from the manual transmission 4 to the operating device (differential gear) 6 through the propulsion shaft (propeller shaft) 5, and is transmitted from the operating device 6 to the wheels 8 through the drive shaft (drive shaft) 7. Thereby, the motive power of the engine 1 is transmitted to the wheels 8 and the vehicle travels.

  The ECU 2 is a microcontroller that comprehensively performs electrical control in charge of control of the engine 1 by an electric circuit, and mainly controls the fuel injection amount and intake air amount of the engine 1 to output the engine 1. Is controlling.

  The ECU 2 includes a pre-stored control map (control performance diagram) 9 for controlling the fuel injection amount and intake air amount of the engine 1, and the control map 9 includes the number of revolutions of the engine 1. In addition to the normal torque curve (normal control performance line) 10 based on the performance of the engine 1 as a torque curve (control performance line) indicating the torque generated against the fuel, the fuel consumed more than the normal torque curve 10 is used. A low fuel consumption torque curve (performance line for low fuel consumption control) 20, 30, and 40 set so as to be reduced is provided.

In addition, the normal torque curve 10 provided in the control map 9 is provided with a governing start point 12 that defines the governing start rotational speed N _GS 1, and the low fuel consumption torque curves 20, 30 and 40 are provided with a governing start rotational speed N. Low fuel consumption governing start speeds 22, 32, and 42 that respectively define low fuel consumption governing start rotational speeds N _GS 2, N _GS 3, and N _GS 4 having a lower rotational speed than _GS 1 are provided.

  In addition, the ECU 2 stores road load horsepower (running load resistance horsepower) calculation means M1, surplus horsepower calculation means M2, reference horsepower calculation means M3, torque curve, which are stored as a program for controlling the output of the engine 1. A selection means (control performance line selection means) M4, an output control means M5, and a selection release means M6 are provided.

First, the control map 9 will be described with reference to FIGS. As shown in FIG. 2, the control map 9 includes four torque curves 10, 20, 30, and 40 based on the engine speed (hereinafter referred to as “speed”) and the engine output torque (hereinafter referred to as “torque”). Is remembered.

The normal torque curve 10 includes a maximum horsepower point 11 that defines the maximum horsepower P1 of the engine 1, a governing start speed 12 that defines the governing start rotational speed N _GS 1 at which torque limitation starts, and a no-load maximum rotational speed ( _NLM ) NLM point (no-load maximum rotation speed point) 13 that defines N _NLM is provided.

  In the horsepower increase section 14 from the start of the engine 1 to the maximum horsepower point 11, the output horsepower increases to the maximum horsepower P1 as the rotational speed increases. The maximum horsepower P1 is the maximum horsepower that the engine 1 can output, and is determined based on the performance of the engine 1 such as the type of the engine 1 and the number of cylinders.

  In the horsepower reduction section 15 from the maximum horsepower point 11 to the governing start point 12, the output horsepower gradually decreases from the maximum horsepower P1 as the rotational speed increases. In the governing section 16 from the governing start point 12, as the fuel injection amount and the intake air amount are limited, the torque is limited, and the maximum horsepower that can be output decreases at a stretch.

The governing start rotational speed N _GS 1 defined by the governing start point 12 is determined by limiting the fuel injection amount and the intake air amount so that the torque does not become high torque when the rotational speed of the engine 1 is in a high rotational speed region. This is the rotation speed at which the limit of This governing rotation speed N _GS 1 is displayed on a tachometer (not shown), and serves as a shift point that prompts the driver to change the gear position of the manual transmission 4. Further, from the Gabaningu start rotational speed N _{GS 1,} the torque of the engine 1 is suppressed, and a racing feeling of the engine 1 is the driver becomes easy feeling, blow from Gabaningu start rotational speed N _{GS 1} up It is possible to prompt the driver to change the gear stage also by feeling.

The no-load maximum rotational speed N _NLM defined by the NLM point 13 is the maximum rotational speed of the engine 1 when idling, and is high when a gear stage is shifted by the traveling manual transmission 4 or when an air tank (not shown) is filled. This is the number of revolutions reached when idling (high rpm idling).

  The low fuel consumption torque curves 20, 30 and 40 are set so that the fuel consumed in order decreases stepwise. Specifically, the low fuel consumption torque curves 20, 30, and 40 are set so that the maximum horsepower that can be output in order decreases, and the low fuel consumption torque curve 20 has a limited horsepower P2 that is smaller than the maximum horsepower P1. Further, the low fuel consumption torque curve 30 is set to a limited horsepower P3 smaller than the limited horsepower P2, and the low fuel consumption torque curve 40 is set to a limited horsepower P4 smaller than the limited horsepower P3.

Further, the low fuel consumption torque curves 20, 30, and 40 are set such that the low fuel consumption governing start points 22, 32, and 42 provided in the respective low fuel consumption torque curves sequentially decrease in rotation speed. Specifically, as shown in FIG. 2, the low fuel consumption governing start rotational speed N _GS 2 defined by the low fuel efficient governing start point 22 is based on the governing start rotational speed N _GS 1 defined by the governing start point 12 of the normal torque curve 10. The low fuel consumption governing start speed N _GS 3 defined by the low fuel consumption governing start point 32 is lower than the low fuel consumption governing start rotational speed N _GS 2, and the low fuel consumption governing start point 42 is defined. The low fuel consumption governing start rotation speed N _GS 4 is set to be lower than the low fuel consumption governing start rotation speed N _GS 3.

  Here, the low fuel consumption torque curve 20 will be described as an example. As shown in FIG. 3, the low fuel consumption torque curve 20 includes a limited horsepower point 21, a low fuel consumption governing start point 22, a bending point (route point) 23, and an NLM point 13.

  The limited horsepower point 21 defines a limited horsepower P2. The low fuel consumption torque curve 20 includes a horsepower increase section 24 along a part of the horsepower increase section 14 of the normal torque curve 10 from the start of the engine 1 to the limit horsepower point 21, and in this horsepower increase section 24, As the rotational speed increases, the output horsepower increases to the limit horsepower P2.

  The range from the limited horsepower point 21 to the low fuel consumption governing start point 22 is an equal horsepower section 25 along the equal horsepower line of the limited horsepower P2, and the constant horsepower section 25 can output even if the rotation speed increases. The maximum horsepower is limited to the limited horsepower P2. Therefore, in this equal horsepower section 25, it is possible to reduce the fuel consumption because the vehicle speed is prevented from increasing more than necessary.

The low fuel consumption governing start point 22 defines the low fuel consumption governing start rotation speed N _GS 2. The low fuel consumption governing start rotational speed N _GS 2 is set to be lower than the governing start rotational speed N _GS 1 of the normal torque curve 10.

  That is, when the output of the engine 1 is controlled along the low fuel consumption torque curve 20, the gear stage of the manual transmission 4 is compared with when the output of the engine 1 is controlled along the normal torque curve 10. The shift point becomes faster.

  As shown in FIG. 2, the engine 1 has a fuel consumption rate (SFC) defined as an index indicating how much fuel can be traveled over a certain distance or a travel distance per unit capacity of fuel, The control map 9 is provided with regions SFC2, SFC3, and SFC4 in which the fuel consumption rate increases in order from the region SFC1 with the lowest fuel consumption rate.

  Compared to the case where the engine 1 is controlled along the normal torque curve 10, the low fuel consumption torque curve 20 has a fuel consumption earlier than the case where the engine 1 is controlled along the normal torque curve 10. Since the shift of the gear stage of the manual transmission 4 to the low-rate region SFC2 is promoted, the fuel consumption can be reduced.

  As shown in FIG. 3, the bending point 23 is a point with a lower torque, a higher rotation than the low fuel consumption governing start point 22, a higher torque than the NLM point 13, and a lower rotation point. It is a point provided in front. Then, the low fuel consumption governing starting point 22 to the NLM point 13 are formed to be bent at the bending point 23.

  Specifically, the bending point 23 is arranged on the origin side from the straight line connecting the low fuel consumption governing start point 22 and the NLM point 13 so that the low fuel consumption governing start point 22 to the NLM point 13 bend with the origin side convex. Formed.

This turning point 23 is the state of the engine 1, for example, the feeling of the driver when the output of the engine 1 is controlled along the low fuel consumption governing section 26 from the fuel saving governing start point 22 to the turning point 23. The feeling of blowing up is determined so as to be substantially the same as when the control is performed along the governing section 16 of the normal torque curve 10.
Specifically, the shape from the low fuel consumption governing start point 22 to the bending point 23 is substantially the same as the shape from the governing start point 12 to the NLM point 13 in the governing section 16 of the normal torque curve 10, that is, The slope of the straight line of the low fuel consumption governing section 26 is made substantially equal to the slope of the straight line of the governing section 16.

The slope of the straight line in the governing section 16 is defined as slope θ1, and the slope of the straight line in the low fuel consumption governing section 26 is defined as slope θ2. The inclination θ1 and the inclination θ2 represent the relationship by the following mathematical formula (1).

As described above, the output of the engine 1 controlled along the low fuel consumption governing section 26 is substantially the same as the output of the engine 1 controlled along the governing section 16, so that the low fuel consumption governing start rotational speed N _{GS is obtained.} The feeling of blowing up from 2 can be made the same as the feeling of blowing up when controlled along the normal torque curve 10. Thereby, even when the output is controlled along the low fuel consumption torque curve 20, a shift operation or the like can be performed with the same feeling as when the output is controlled along the normal torque curve 10.

In addition, from the bending point 23 to the NLM point 13 is an idling section 27 so that the maximum engine speed of the engine 1 when idling in the low fuel consumption torque curve 20, that is, the no-load maximum engine speed N _NLM is not changed. Set to Thereby, the discomfort can be suppressed by being the same as that of the normal torque curve 10 at the time of shifting during traveling or at the time of high idling when filling an air tank (not shown).

The torque T1 indicated by the NLM point 13 that defines the no-load maximum rotational speed N _NLM is determined by the performance of the engine 1, etc., and the torque T2 indicated by the bending point 23 is greater than the torque T1, preferably It is set to a value about 10 kgm larger.

Similar to the low fuel consumption torque curve 20, the low fuel consumption torque curve 30 includes a limit horsepower point 31 that defines the limited horsepower P 3, a low fuel consumption governing start point 32 that defines the low fuel consumption governing start rotational speed N _GS 3, Point 33, a horsepower increase section 34 to the limit horsepower point 31, an equal horsepower section 35 from the limit horsepower point 31 to the low fuel consumption governing start point 32, and a point from the low fuel consumption governing start point 32 to the turning point 33. A low fuel consumption governing section 36 and an idling section 37 from the turning point 33 to the NLM point 13 are provided.

Similarly, fuel-efficient torque curve 40 is provided with a limit horsepower point 41 which defines the limit horsepower P4, and low fuel consumption Gabaningu starting point 42 that defines a low fuel consumption Gabaningu start rotational speed N _{GS 4,} and Orikyokuten 43, limits A horsepower increase section 44 to the horsepower point 41, an equal horsepower section 45 from the limited horsepower point 41 to the low fuel consumption governing start point 42, a low fuel consumption governing section 46 from the low fuel consumption governing start point 42 to the turning point 43, An idling section 47 from the bending point 43 to the NLM point 13 is provided.

  Since the characteristics of each point and each section of the low fuel consumption torque curves 30 and 40 are the same as those of the low fuel consumption torque curve 20, the description thereof is omitted.

Next, each means of the ECU 2 will be described. The road load horsepower calculating means M1 is a means for calculating road load horsepower (traveling load resistance horsepower) _PRL . Specifically, it is means for calculating the road load horsepower _PRL based on road conditions such as road gradient and weather conditions and vehicle conditions such as vehicle running resistance according to the vehicle load and vehicle speed.

The road load horsepower calculation means M1 includes road gradient acquisition means for acquiring a road gradient from a detection signal such as an acceleration sensor, road surface analogy means for analogizing a road surface condition from received weather information, and the like as road condition acquisition means. Further, as vehicle status acquisition means, vehicle speed acquisition means for acquiring vehicle speed from a detection signal such as a speed sensor, travel resistance calculation for calculating travel resistance including rolling resistance, air resistance, gradient resistance, and acceleration resistance from vehicle speed and road gradient Means, weight calculation means for calculating the current total vehicle weight GVW of the vehicle using the running resistance and the driving force of the vehicle. Note that these road status acquisition means and vehicle status acquisition means use known techniques, and the details thereof will be omitted.

Then, the road load horsepower calculation means M1 calculates the road load horsepower P _RL considering all values acquired and calculated in them. The road load horsepower _PRL is a value that increases as the road gradient increases, increases as the vehicle speed increases, and increases as the current total vehicle weight GVW increases.

Margin horsepower calculation means M2 is a means for calculating the minimum margin horsepower P _EX required to accelerate the vehicle. Normally, the surplus horsepower P _EX is a horsepower obtained by subtracting the road load horsepower _PRL from the horsepower output from the engine 1, and the surplus horsepower calculation means M2 calculates the surplus horsepower _PEX as the current total vehicle power of the vehicle. It is calculated based on the weight ratio R between the weight GVW and the maximum total vehicle weight GVW _MAX and the horsepower reference value P1 ′ determined from the maximum horsepower P1 based on the performance of the engine 1.

Specifically, the surplus horsepower _PEX is calculated using the following mathematical formula (2).

A value obtained by multiplying the constant k in the above formula (2) and the maximum horsepower P1 is a horsepower reference value P1 ′. The constant k is a constant determined on the basis of the load amount and size of the vehicle, is a constant obtained by experiments and the like, and is set to satisfy the following formula (3).

Further, it is desirable that the constant k is set to be larger as the maximum vehicle total weight GVW _MAX is heavier and smaller as the maximum horsepower P1 is larger.

The surplus horsepower P _EX calculated by the surplus horsepower calculating means M2 becomes a value that increases as the current total vehicle weight GVW of the vehicle increases, as is apparent from the above formula (2).

Referring horsepower calculation means M3 is a means for adding road load horsepower P _RL and margin horsepower P _EX calculated above. Therefore, the reference horsepower _PRE is set to the minimum horsepower (road load horsepower _PRL ) necessary for accelerating the current vehicle to the minimum horsepower required for traveling based on the current road condition and vehicle condition. Of horsepower (extra horsepower _PEX ) is added. The reference horsepower _PRE is all set to the maximum horsepower P1 when the calculated value is larger than P1.

The torque curve selection means M4 selects any one of the normal torque curve 10 and the low fuel consumption torque curves 20, 30, and 40 based on at least one of the vehicle situation of the vehicle on which the engine 1 is mounted and the road situation. It is a means to select.

Specifically, based on the reference horsepower P _RE, a means for selecting one from among the normal torque curve 10 and the low fuel consumption torque curve 20, 30, and 40 of a control map 9 described above. _Is it equal to the reference horsepower _PRE from the maximum horsepower P1, the horsepower limit P2, the horsepower limit P3, and the horsepower limit P4 that are the maximum output horsepower of each of the torque curves 10, 20, 30, and 40? or reference horsepower P _RE select the one closest to the large and reference horsepower P _RE than a means of a torque curve TC, which is selected to have its output maximum possible horsepower.

As shown in FIG. 4, for example, in the case of reference horsepower P _RE 1, the normal torque curve 10 is selected. In the case of the reference horsepower _PRE2 , the low fuel consumption torque curve 20 is selected. In the case of the reference horsepower _PRE3 , the low fuel consumption torque curve 30 is selected.

As a result, it is possible to select the torque curve TC with the lowest consumed fuel while considering the surplus horsepower P _EX for accelerating the vehicle. Thereby, fuel consumption can be improved while avoiding insufficient output of the engine 1.

  The output control means M5 controls the output of the engine 1 along the torque curve TC selected from the normal torque curve 10 and the low fuel consumption torque curves 20, 30, and 40 by executing the torque curve selection means M4. Means. Specifically, it is means for adjusting the fuel injection amount by controlling an injector (not shown) of the engine 1 or adjusting the intake amount by controlling an intake throttle, an EGR valve, etc. (not shown).

  In particular, the output control means M5 is provided for the engine 1 along the equal horsepower sections 25, 35, and 45 and the low fuel consumption governing sections 26, 36, and 46 in the low fuel consumption torque curves 20, 30, and 40, respectively. By controlling the output, fuel consumption can be reduced.

  The selection canceling means M6 is a means for manually canceling when a torque curve selecting means M4 other than the normal torque curve 10 is selected. Specifically, when the low fuel consumption torque curves 20, 30, and 40 are selected as the torque curve TC, when the accelerator pedal SW1 shown in FIG. 1 is largely or suddenly depressed, the normal torque curve is used as the torque curve TC. Means for selecting 10.

  This selection canceling means M6 is a means for setting the torque curve TC to the normal torque curve 10 on the same principle as a manual shift operation for manually switching the gear stage of the automatic transmission to a low speed, so-called kick down. For example, the accelerator pedal SW1 is configured to be depressed beyond the depression amount that determines the fuel injection amount or the like, and is released when the accelerator pedal SW1 is depressed beyond the depression amount.

Next, a control method of the engine 1 according to the embodiment of the present invention will be described with reference to the flowchart of FIG. First, the load / load horsepower calculating means M1 is executed to perform step S10 for calculating the load / load horsepower _PRL . Then perform the margin horsepower calculation means M2, performs step S20 of calculating the margin horsepower _{P EX.} The order of step S10 and step S20 may be reversed.

When the load load horsepower _{P RL} and margin horsepower _{P EX} is calculated, then carried the reference horsepower calculation means M3, performing step S30 of calculating the reference horsepower _{P RE.} Next, the torque curve selection means M4 is implemented, and step S40 for selecting the torque curve TC is performed. Next, the output control means M5 is implemented, and step S50 for controlling the output of the engine 1 along the torque curve TC is performed, and this control method is completed.

  When the selection canceling means M6 is implemented during the above control method, the normal torque curve 10 may be selected as the torque curve TC immediately even during the above control method.

  Next, an ECU (control device) 51 of the engine 50, the engine 50, and a control method of the engine 50 according to the second embodiment of the present invention will be described with reference to FIGS. The power of the engine 50 of the second embodiment is transmitted to the propulsion shaft 5 via the automatic transmission 52.

  The ECU 51 includes a control map 53 instead of the control map 9 of the first embodiment, and further includes a shift control means M7 that controls the clutch 3 and the automatic transmission 52.

  In the control map 53, in addition to the normal torque curve 10, the consumed fuel decreases stepwise. Specifically, the maximum horsepower that can be output is limited to limited horsepower P6, P7, and P8. Fuel economy torque curves 60, 70, and 80 are provided.

Further, the low fuel consumption governing governing speed stipulating the low fuel consumption governing start rotational speed N _GS 6 lower than the governing start rotational speed N _GS 1 in the low fuel efficient torque curves 60, 70, and 80 provided in the control map 53. A starting point 62, 72, and 82 are provided.

  As shown in FIG. 7, the low fuel consumption torque curves 60, 70, and 80 are formed in substantially the same manner as the low fuel consumption torque curve 20 of the first embodiment, but the low fuel consumption governing start points 62, 72 are formed. , And 82 and the bending points (via points) 63, 73, and 83 are different.

The low fuel consumption torque curves 60, 70, and 80 are governing start points 62, 72 that define a low fuel consumption governing start rotational speed N _GS 6 that is lower than the governing start rotational speed N _GS 1 of the normal torque curve 10, and 82 are provided.

In the first embodiment, a low fuel consumption governing start point 22 that defines different low fuel consumption governing start rotational speeds N _GS 2, N _GS 3, and N _GS 4 for each of the low fuel consumption torque curves 20, 30, and 40. , 32, and 42 are provided, but in the second embodiment, the low fuel consumption governing start rotational speed N _GS 6 of each of the low fuel consumption torque curves 60, 70, and 80 is set to be the same.

This is because in the second embodiment, power is transmitted via the automatic transmission 52, and the low fuel consumption governing start rotational speed N _GS 6 of each of the low fuel consumption torque curves 60, 70, and 80 is set. By making them the same, the shift control means M7 can be simplified. Note that the shift rotational speed in the automatic transmission 52 is automatically determined so as to achieve low fuel consumption according to the driving situation, so there is no need to vary the low fuel consumption governing start rotational speed N _GS 6.

  Further, the low fuel consumption torque curves 60, 70, and 80 are provided with curved points 63, 73, and 83 instead of the bending points, and the low fuel consumption governing start points 62, 72, and 82 to the NLM point 13 are provided. The curved points 63, 73, and 83 are formed so as to be curved while passing.

More specifically, the curved points 63, 73, and 83 are arranged on the origin side with respect to the straight line connecting the low fuel consumption governing start points 62, 72, and 82 and the NLM point 13, and the low fuel consumption governing start points 6 are arranged.
2, 72, and 82 to NLM point 13 are formed to be curved with the origin side as a convex.

  As a result, the output of the engine 1 can be controlled in the same manner as the governing section 16 of the normal torque curve 10 from the low fuel consumption governing starting points 62, 72, and 82 to the bending points 63, 73, and 83. From 63, 73, and 83 to NLM point 13 can be set as the idling section.

According to the control methods for the ECUs 2 and 50, the engine 1 and the engine 1 of the engine 1 of the first and second embodiments, in addition to the normal torque curve 10 based on the performance of the engine 1, Among the low fuel consumption torque curves 20, 30, and 40 (60, 70, and 80) set so as to reduce the consumed fuel, the road load horsepower _PRL that changes depending on the vehicle condition and the road condition and the vehicle The torque curve TC is selected based on the reference horsepower _PRE calculated by adding the surplus horsepower P _EX that changes depending on the weight, and the output of the engine 1 is controlled along the torque curve TC. Thereby, the opportunity of the low fuel consumption effect by the low fuel consumption torque curves 20, 30, and 40 (60, 70, and 80) in which the maximum output that can be output is suppressed can be increased, and the fuel consumption can be reduced. .

More specifically, in the first embodiment, each of the low fuel consumption torque curves 20, 30, and 40 is a low fuel consumption governing start rotation whose rotation speed is lower than the governing start rotation speed N _GS 1 of the normal torque curve 10. Low fuel consumption governing starting points 22, 32, and 42 are provided that define the numbers N _GS 2, N _GS 3, and N _GS 4, respectively. As a result, it is possible to promptly shift the engine 1 to a region where the fuel consumption rate is low, rather than controlling the output of the engine 1 along the normal torque curve 10, thereby reducing fuel consumption. can do.

In the second embodiment, each of the low fuel consumption torque curves 60, 70, and 80 has a low fuel consumption governing start rotational speed N _GS 6 having a lower rotational speed than the governing start rotational speed N _GS 1 of the normal torque curve 10, respectively. Are provided for low fuel consumption governing starting points 62, 72, and 82, respectively. As a result, the engine speed can be shifted to an area where the fuel consumption rate is low, rather than controlling the output of the engine 1 along the normal torque curve 10, so that the fuel consumption can be reduced. it can.

  In the first embodiment, the maximum horsepower that can be output from each of the low fuel consumption torque curves 20, 30, and 40 is limited to the limited horsepower P2, P3, and P4. In the present embodiment, the maximum horsepower that can be output by each of the low fuel consumption torque curves 60, 70, and 80 is limited to the limited horsepower P6, P7, and P8, thereby reducing the horsepower consumption by suppressing the overspeed. Through this, fuel consumption can be reduced.

Then, in the first and second embodiments, while reducing fuel consumption as described above, since selecting the torque curve TC based on road load horsepower P _RL and margin horsepower P _EX, broad engine 1 and By controlling the outputs of the engines 1 and 50 along the optimum torque curve TC with respect to 50 operating conditions, it is possible to alleviate the shortage of the outputs of the engines 1 and 50.

  Note that the control map 53 of the second embodiment can be applied to the first embodiment in which the manual transmission 4 is provided as a transmission, and conversely the first embodiment in which an automatic transmission 52 is provided as a transmission. The control map 9 of the first embodiment can also be applied to the second embodiment.

In addition, the low fuel consumption torque curves 20, 30, and 40 of the control map 9 of the first embodiment are formed by providing the bending points 23, 33, and 43, but instead of the second embodiment, It may be formed by providing inflection points such as low fuel consumption torque curves 60, 70, and 80 in the form. On the contrary, the bending points 63, 73, and 83 of the low fuel consumption torque curves 60, 70, and 80 of the second embodiment are provided instead of the bending points as in the first embodiment. May be.

  In addition, the torque curves stored in the control maps 9 and 53 may be at least two of the normal torque curve 10 and the low fuel consumption torque curve 20 (60), and the number is not limited.

Furthermore, in the above embodiment, the normal torque curve 10 and the low fuel consumption torque curves 20, 30, and 40 (60, 70, and 80) provided in the control map 9 (53) are respectively converted into the engine 1 (50). In the example described above, the engine is separated from the start (the number of revolutions is zero) to the maximum number of revolutions N _MAX . However, the low fuel consumption torque curves 20, 30, and 40 (60, 70, and 80) , 31, and 41 (61, 71, and 81).

  In addition, the shape of each torque curve 10, 20, 30, 40, 60, 70, and 80 of the above embodiment is an example, and the present invention is not limited to that shape.

  The present invention can also be applied to the case where power transmission from the engine 1 is routed through a semi-automatic transmission in which only the operation of the clutch 3 is automated.

  In addition to the normal control performance line, the control device for an internal combustion engine of the present invention is provided with a fuel efficiency control performance line set so as to reduce fuel consumed from the normal control performance line. The internal combustion engine along the control performance line selected based on the driving load resistance horsepower that changes depending on the vehicle and road conditions and the surplus horsepower that changes depending on the weight of the vehicle The fuel consumption can be reduced based on vehicle conditions and road conditions while controlling the output of the engine and alleviating the lack of output of the internal combustion engine that the driver feels, so that it can be used for a diesel engine.

1, 50 engine (internal combustion engine)
2, 51 ECU (control device for internal combustion engine)
4, 52 Transmission 9, 53 Control map (control performance diagram)
10 Normal torque curve (performance line for normal control)
11 Maximum horsepower point 12 Governing start point 13 NLM point (no-load maximum rotation speed point)
20, 30, 40, 60, 70, 80 Low fuel consumption torque curve (performance line for low fuel consumption control)
21, 31, 41, 61, 71, 81 Limit horsepower points 22, 32, 42, 62, 72, 82 Low fuel consumption governing start points 23, 33, 43 Bending points (via points)
63, 73, 83 Inflection point (via point)

Claims (8)

In addition to the performance line for control indicating the torque generated with respect to the rotational speed of the internal combustion engine, in addition to the performance line for normal control having a governing start point that defines the governing start rotational speed based on the performance of the internal combustion engine, Low fuel consumption control that has a low fuel consumption governing start point that defines a low fuel consumption governing start rotational speed that is lower than the governing start rotational speed, and that is set to reduce fuel consumption from the normal control performance line One or more performance lines
During operation of the internal combustion engine, any one of the performance line for normal control and the performance line for fuel efficiency control selected based on at least one of a vehicle situation of a vehicle equipped with the internal combustion engine or a road situation A control apparatus for an internal combustion engine, further comprising output control means for controlling the output of the internal combustion engine. The normal control performance line is provided with a no-load maximum rotation speed point that defines the maximum rotation speed under no load, and the low fuel consumption control performance line has a torque lower than that of the low fuel consumption governing start point and high. Provide a via point for rotation and low torque at a higher torque than the unloaded maximum rotation speed point,
The performance line for low fuel consumption control is formed so that the low fuel consumption governing start point to the no-load maximum rotational speed point bend at the via point or pass through the via point while being curved. The control apparatus for an internal combustion engine according to claim 1. The normal control performance line is provided with a no-load maximum rotation speed point that defines the maximum rotation speed under no load, and the low fuel consumption control performance line has a torque lower than that of the low fuel consumption governing start point and high. Provide a via point for rotation and low torque at a higher torque than the unloaded maximum rotation speed point,
The shape of the fuel efficiency control performance line from the fuel efficiency governing start point to the waypoint is substantially the same as the shape of the normal control performance line from the governing start point to the no-load maximum rotational speed point. The control device for an internal combustion engine according to claim 1 or 2, wherein the control device is formed as follows.   The normal control performance line is formed so as to be able to output a maximum horsepower based on the performance of the internal combustion engine, and the fuel efficiency control performance line is limited so that the maximum horsepower that can be output is lower than the maximum horsepower. 4. The motor is limited to horsepower, and as the number of revolutions of the internal combustion engine increases from the limited horsepower, the low fuel consumption governing start point is formed along an equal horsepower line of the limited horsepower. The control device for an internal combustion engine according to any one of the above.   The control apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein a plurality of the fuel efficiency control performance lines in which the respective fuel efficiency governing start rotational speeds are decreased stepwise are provided.   The control apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein a plurality of the fuel efficiency control performance lines having the same fuel efficiency governing start rotational speed are provided.   A vehicle comprising the control device for an internal combustion engine according to any one of claims 1 to 6. During operation of the internal combustion engine, a governing start point is provided that defines a governing start rotational speed based on the performance of the internal combustion engine based on at least one of a vehicle situation of a vehicle equipped with the internal combustion engine or a road situation. A fuel efficiency governing start point that defines a fuel efficiency governing start speed that is lower than the normal control performance line and the governing start speed is provided so as to reduce fuel consumption than the performance line for normal control. A method for controlling an internal combustion engine comprising: selecting any one of the fuel efficiency control performance lines set in the control line and controlling the output of the internal combustion engine along the selected control performance line .

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