JPH10203202A - Torque fluctuation suppressor of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress shock to be transmitted to a tire by changing a supply time of fuel to be supplied within a combustion cylinder of an internal combustion engine according to a torque fluctuation suppression signal. SOLUTION: Target engine torque determined by a target torque arithmetic means 37 is inputted in a torque fluctuation arithmetic means 36. The torque fluctuation arithmetic means 36 inputs engine torque calculated by an estimation means 35 and calculates the rate of change of engine torque. This rate of change and target engine torque are compared, whether torque fluctuation is generated or not is judged, and a deviation of the torque fluctuation and the engine torque calculated is calculated. When torque fluctuation is generated, a gear ratio according to the deviation is calculated by a gear ratio arithmetic means 38, torque fluctuation is suppressed and a supply time of fuel to be supplied within a combustion cylinder of an internal combustion engine 1 is changed. Thus, shock to be transmitted to a tire can be suppressed, fuel consumption can be reduced and operability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a torque fluctuation suppressing device for an internal combustion engine.

[0002]

2. Description of the Related Art An air-fuel ratio of an internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 4-362221 is a known example in which a torque shock is not generated when switching between a stratified operation state and a uniform air-fuel mixture operation state. There is a control unit.

This publication discloses a fuel injection valve for supplying the fuel into an engine combustion chamber. When the load applied to the internal combustion engine is lower than a predetermined load, the fuel is injected so that the air-fuel mixture gathers around the spark plug. When the load applied to the internal combustion engine is higher than the set load, a uniform air-fuel mixture is formed in the combustion chamber and the air-fuel ratio is adjusted to the first air-fuel ratio. An air-fuel ratio control device that controls the air-fuel ratio to a smaller second air-fuel ratio is described. Further, the air-fuel ratio control device includes an intake air amount control means for controlling an intake air amount supplied into a cylinder of the internal combustion engine, and the intake air amount control device when a load applied to the internal combustion engine exceeds the set load. Control signal output means for outputting a control signal for reducing the intake air amount to the amount control means, and combustion until the intake air amount decrease period from when the control signal is output to when the intake air amount actually decreases is elapsed. Fuel injection control means for increasing the fuel injection amount while maintaining the operation state of stratifying the interior of the chamber, and transition means for shifting to an operation state for forming a uniform mixture in the combustion chamber after the intake air amount reduction period has elapsed. It has.

According to the technique described in this publication, the amount of fuel injection is increased to prevent a torque shock from occurring in a transition from a stratified operation state to a uniform air-fuel mixture operation state. It is.

[0005]

According to the technology described in the above publication, the torque at the time of transition from the stratified operation state (compression stroke injection) to the operation state in which a uniform mixture is formed (intake stroke injection) is obtained. Although the level difference is smoother than in the prior art, this transition in the engine output torque-air-fuel ratio diagram changes on the compression stroke injection line and the intake stroke injection line. Is inevitable.

The present invention provides a torque fluctuation suppressing device that suppresses torque fluctuation by providing a torque fluctuation suppressing region when transitioning from the compression stroke injection line to the intake stroke injection line in the engine output torque-air-fuel ratio diagram. The purpose is to do.

[0007]

An internal combustion engine in which torque is output by switching between a stratified operation state and a uniform air-fuel mixture operation state is quite effective in terms of achieving both low fuel consumption and a feeling of acceleration. It is.

Problems such as torque shock and deterioration of the exhaust occur in order to achieve both a reduction in fuel consumption and a feeling of acceleration, and it is essential to solve these problems by applying a new technology. But,
The improvement of the efficiency of the internal combustion engine alone does not lead to the improvement of the overall efficiency including the drive system, and the combination with the CVT (continuously variable transmission) is essential. Therefore, it is necessary to suppress the torque shock using the CVT in order to significantly reduce fuel consumption and achieve a sense of acceleration.

In addition, a vehicle has been developed in which the CVT is provided with a manual operation means and travels as if it were a manual stepped transmission, and suppression of torque shock of the internal combustion engine by speed ratio control has become an important issue.

Further, as described above, when shifting from the stratified mixture region to the homogeneous mixture region, the torque shock suppression and the gear ratio control by the cooperative control of the fuel injection amount and the intake air amount are combined to change the gear ratio. The range of change in the ratio control can be reduced, and the fuel consumption can be further reduced (fuel consumption increases as the engine speed increases).

Specifically, the above-mentioned problem is solved by the following device. That is, the present invention relates to a torque fluctuation suppressing device for an internal combustion engine having a transmission that adjusts and transmits the output of an internal combustion engine to a power transmission system with a transmission ratio adjusted. Intake air amount control means for controlling the amount, fuel supply timing control means for controlling the supply timing of the fuel supplied into the combustion cylinder of the internal combustion engine, and a load received by the internal combustion engine are predetermined. Control signal output means for outputting a control signal to reduce the intake air amount to the intake air amount control means when the value exceeds the control value, and the output of the control signal or a signal corresponding to the control signal. Torque fluctuation suppression signal output means for outputting a torque fluctuation suppression signal for suppressing a torque fluctuation of the internal combustion engine by changing a gear ratio of the engine, wherein the torque fluctuation suppression signal output means Wherein the supply timing of the fuel supplied to the combustion cylinder of the internal combustion engine is changed by the fuel supply timing control means in accordance with the torque fluctuation suppression signal output from the internal combustion engine. A suppression device is provided.

[0012] Preferably, there is provided fuel amount control means for controlling the amount of fuel supplied into the combustion cylinder of the internal combustion engine by the output of the control signal or a signal corresponding to the control signal.

Preferably, there is provided switching means for switching from lock-up to slide lock-up by outputting the control signal or a signal corresponding to the control signal.

Preferably, the control signal or a signal corresponding to the control signal is an in-cylinder pressure signal of a combustion cylinder of the internal combustion engine.

[0015] Preferably, the control signal or a signal corresponding to the control signal is obtained from an estimated torque value.

According to another embodiment of the present invention, there is provided a torque fluctuation suppressing device for an internal combustion engine having a transmission for adjusting the transmission ratio and transmitting the output of the internal combustion engine to a power transmission system. And a torque-speed ratio characteristic determining device for calculating or determining a torque-speed ratio characteristic representing a relationship between the output torque and the speed ratio of the internal combustion engine, or detecting a torque fluctuation of the internal combustion engine. Detecting means for changing the gear ratio of the transmission according to a detection signal representing the torque fluctuation detected by the detecting means, based on the value determined by the torque-speed ratio characteristic determining device, thereby changing the torque fluctuation. A torque fluctuation suppressing device for an internal combustion engine, characterized by having a suppressing means.

[0017] Preferably, the detection signal is a valve timing switching signal indicating an opening / closing timing of a valve for supplying intake air supplied to a combustion cylinder of the internal combustion engine. Preferably, the detection signal is an ON / OFF signal of the air conditioner.
This is an OFF control signal.

Preferably, the detection signal is provided such that when the engine receives a load lower than a predetermined set load, a mixture of intake air and fuel gathers around a spark plug of a combustion cylinder of the internal combustion engine. Stratified inside,
When the internal combustion engine receives a load higher than the above set load, it is a signal for changing the intake air amount of the internal combustion engine which is configured to form a uniform mixture in the combustion cylinder.

[0019] Preferably, the detection signal is such that when the engine receives a load lower than a predetermined set load, a mixture of intake air and fuel gathers around a spark plug of a combustion cylinder of the internal combustion engine. Stratified inside,
When the internal combustion engine receives a load higher than the set load, it is an estimated torque fluctuation signal that accompanies a change in the intake air amount of the internal combustion engine that forms a uniform mixture in the combustion cylinder.

According to still another embodiment of the present invention, there is provided a torque fluctuation suppressing device for an internal combustion engine including a motor for adjusting the motor current and transmitting the output of the internal combustion engine to a power transmission system. And a torque-motor current characteristic determining device for determining a torque-motor current characteristic representing a relationship between the output torque and the motor current by calculation or selecting from a stored value, and detecting a torque fluctuation of the internal combustion engine. Detecting means for changing the motor current of the motor based on a value determined by the torque-motor current characteristic determining device in accordance with a detection signal representing the torque fluctuation detected by the detecting means, thereby suppressing the torque fluctuation. And a torque fluctuation suppressing device for an internal combustion engine, comprising:

Preferably, the detection signal is a switching signal of a valve timing indicating an opening / closing timing of a valve for supplying intake air supplied to a combustion cylinder of the internal combustion engine. Preferably, the detection signal is an ON / OFF signal of the air conditioner.
This is an OFF control signal.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings.

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

The engine 1 is a four-cylinder / in-cylinder fuel injection engine in this embodiment. In this engine 1,
An ignition device 2 is provided. The ignition device 2 has four ignition plugs 3 corresponding to the number of cylinders of the engine 1. Further, a fuel injection device 4 for directly injecting fuel into four cylinders is provided for each cylinder, and the device 4 has fuel injection valves 5 corresponding to the number of cylinders of the engine 1. The in-cylinder injection engine 1 is an engine capable of achieving both a great reduction in fuel consumption and a sense of acceleration by reducing the pumping loss by increasing the lean limit and increasing the volumetric efficiency due to the cooling effect of the cylinder intake air.

An intake pipe 6 for taking air into the engine 1 is provided with an electronic control throttle 7 and an air flow meter 8 for adjusting the flow rate of air passing therethrough. The electronically controlled throttle 7 controls the air flow rate by driving the throttle valve 10 with the actuator 9. A throttle valve 10 and an accelerator pedal (not shown) are connected by a mechanical wire (not shown), and an air flow rate is controlled by a control valve (not shown) provided in a pipe that bypasses the upstream and downstream of the valve 10. Is not controlled).

Further, an exhaust pipe 1 provided in the engine 1
1 is provided with an air-fuel ratio detecting means 12 for detecting a ratio of air to fuel supplied to the engine 1 (air-fuel ratio: A / F). Further, an in-cylinder pressure sensor 34 for detecting the output torque of the engine 1 is provided.

A flywheel 14 is attached to a crankshaft 13 of the engine 1. Flywheel 14
Is mounted with an engine output shaft speed sensor 15 for detecting the speed of the crankshaft 11, that is, the engine speed Ne. A torque converter 16 (hereinafter, abbreviated as a torque converter) directly connected to the flywheel 14 and having a lock-up clutch 21 includes a pump 17, a turbine 18, and a stator 19.

The output shaft of the turbine 18, that is, the torque converter output shaft 20, is directly connected to the input pulley 21 of the continuously variable transmission. The torque converter output shaft 20 is provided with a turbine (torque converter output shaft) rotation speed sensor 22 for measuring a pulley input shaft rotation speed Nt.

Further, a hydraulic pump 2 for controlling the side pressure of the input side pulley 23 and the output side pulley 24 to change the turning radius of the contact portion between the input / output pulleys 23, 24 and the belt 25.
6 are provided. The hydraulic pressure generated by the pump 26 is input to an input-side pulley hydraulic control valve 27 and an output-side pulley hydraulic control valve 28, and the valves 27 and 28
Controls the side pressure of the input / output pulleys 23 and 24 to execute a shift.

The output side pulley 24 is connected to an output shaft 29, and is provided with a transmission output shaft rotation speed sensor 30 for detecting the rotation speed of the shaft 29, that is, a so-called vehicle speed sensor 30. These components constitute the continuously variable automatic transmission 31.

Engine 1 and transmission 31 described above
The actuator for driving is controlled by the controller 32. The controller 32 includes an in-cylinder pressure Pi, a throttle opening θ, a turbine speed Nt, an engine speed Ne, a transmission output shaft speed No, a transmission oil temperature Toil, an accelerator pedal depression amount α, and an air-fuel ratio A /
F, the air flow rate Qa, and the manual transmission switch Ssw are input and used for control.

The engine torque control means 33 in the controller 32 outputs control signals to the electronic control throttle 7, the fuel injection device 4 and the ignition device 2. Also,
The engine torque estimating means 35 includes Pi or Ne,
Nt is input and the engine torque is calculated. When calculating the engine torque using Pi, the combustion state in the cylinder of the combustion cylinder can be directly grasped, so that misfire and uniformity (injecting fuel in the intake stroke to equalize the mixture in the cylinder) Thus, it is possible to detect combustion fluctuations occurring when switching between stratification (injecting fuel in the compression stroke and concentrating the air-fuel mixture in the cylinder near the spark plug), and to recognize the torque fluctuations accompanying the combustion fluctuations.

When the engine torque is calculated using Ne and Nt, the engine torque when the torque converter is applied, such as when starting, can be calculated using the torque converter characteristics.

Further, in an operation region other than the torque converter operation, the engine torque can be estimated by using the rotation change rate of Ne.

Next, the engine torque calculated by the estimating means 35 is input to the torque fluctuation calculating means 36.
An engine torque change rate is calculated. This rate of change is compared with the torque fluctuation limit constant calculated by the target torque calculation means 37 or the torque requested by the driver, and it is determined whether or not a torque fluctuation or a feeling of torque shortage that makes the driver feel uncomfortable occurs. A deviation between the torque fluctuation or insufficient torque and the calculated engine torque is calculated.
If a sense of incongruity occurs in torque fluctuation or a sense of torque shortage, that is, when the deviation is large, the gear ratio calculation means 38 calculates a gear ratio in accordance with the deviation, and detects momentary torque fluctuation or torque shortage. to correct. Then, the calculating means 38 obtains the side pressure of the input / output pulleys 23 and 24 for setting the calculated gear ratio, and outputs it to the pressure regulation command generating means 39. The generating means 39 calculates a hydraulic control signal corresponding to the calculated side pressure and outputs the signal to the hydraulic control valves 27 and 28.

As another embodiment, a case may be considered in which the torque of the transmission output shaft is selected as the target torque.
In this case, the torque fluctuation calculating means 36 estimates the actual transmission output shaft torque by multiplying the estimated engine torque by the rotation speed ratio (reduction ratio) of the transmission, and calculates the transmission output shaft torque. And the target torque, the change state of the torque is recognized. An advantage in this case is that since the torque felt by the driver can be directly controlled, control that emphasizes the driver's intention can be realized.

For example, in a vehicle equipped with a system in which six speed ratios of the continuously variable automatic transmission 31 are selected and the six speed ratios are switched by a signal from a manual speed change switch Ssw, a vehicle having the six speed ratios is selected. When the uniform / stratification switching is performed at an arbitrary gear ratio, the torque fluctuation is transmitted to the tire, and the driver feels a shock.

Therefore, the shock transmitted to the tire can be suppressed by recognizing the torque fluctuation as described above and controlling the speed ratio in accordance with the deviation at the time of the uniform / stratification switching. This is possible control because the gear ratio can be continuously changed.

FIG. 2 is a block diagram showing the torque fluctuation suppression in the in-cylinder fuel injection engine. First, the accelerator pedal depression amount detecting means 40 and the engine speed detecting means 1
5 is input to the target torque calculating means 37, and the target engine torque requested by the driver is calculated. The target engine torque refers to the engine torque with respect to the throttle opening at the air-fuel ratio of 14.7.

The computing means 37 stores, for example, map data of the throttle opening using the throttle opening and the engine speed as parameters. The throttle opening data is made to correspond to the depression amount, and the depression amount is calculated. A search is made using the amount and the engine speed as parameters, and the engine torque is output as a target torque. The target torque is input to the fuel calculation means 41, the air-fuel ratio data storage means 42, and the torque fluctuation calculation means 36, respectively.

The engine torque is almost proportional to the fuel amount without considering the efficiency. Therefore, the fuel amount can be calculated from the target torque. In the case of an in-cylinder fuel injection engine, the efficiency is improved by a reduction in pumping loss during stratified lean burn (lean mixture combustion) operation and an improvement in volumetric efficiency during uniform stoichiometric (combustion at an air-fuel ratio of 14.7) operation.
Therefore, based on the actual air-fuel ratio obtained by the air-fuel ratio detecting means 12, the stratified uniform switching timing calculating means 45 determines the stratified / uniform switching timing, and reduces the fuel amount when the calculating means 41 switches uniformly. Perform the correction.

Then, the calculated fuel amount is output to the pulse width generating means 43. At this time, the air amount calculating means 46 calculates a target air amount according to the corrected fuel amount and the target air-fuel ratio, and outputs the target air amount by the throttle opening command generating means 47. The command generating means 47 calculates a target throttle opening with respect to the target air amount and outputs the calculated throttle opening to the electronic control throttle 7.

Further, the actual air amount detected by the air amount detecting means 8 and the calculated target air amount are input to the air amount correcting means 48, and correction is performed so that the actual value matches the target value. Thereby, highly accurate air-fuel ratio control can be realized. The storage means 42 stores an engine torque (or an engine torque equivalent signal) obtained in advance by experiment and an air-fuel ratio using the engine speed as parameters. This air-fuel ratio is determined in consideration of the stratification and uniformity, and also in consideration of the exhaust performance and the torque fluctuation state. The calculating means 36
Then, the deviation between the actual engine torque obtained from the in-cylinder pressure and the target torque is calculated, and the torque fluctuation state is recognized. This deviation is input to the speed ratio correction means 44,
A gear ratio calculation is executed so as to correct the gear ratio determined by the depression amount, the vehicle speed, or the gear ratio detected by the manual operation position detecting means 41.

Then, a hydraulic pressure command value corresponding to the corrected gear ratio is output to the generating means 39, and a hydraulic pressure for controlling the actuators 27 and 28 is output from the generating means 39.

Although the target torque is the engine torque as described above, the transmission output shaft torque may be calculated from the accelerator and the vehicle speed, and the engine torque and the gear ratio may be calculated therefrom.

FIG. 3 is an engine (engine output) torque-target throttle opening degree diagram. Here, the description will be made on the assumption that the engine torque is proportional to the fuel amount.

First, a target engine torque is calculated from the accelerator pedal depression amount (not shown), and the fuel amount is proportionally changed according to the change of the target value. When the fuel amount is small, the target throttle opening is opened in advance (indicated by point A). That is, in the stratified mixture region, the air-fuel ratio is increased (that is, in the lean burn state), and the fuel efficiency is reduced by reducing the pumping loss.

Here, the lean throttle operation is performed when the target throttle opening is below the fuel amount indicated by the broken line, the stoichiometric operation is performed above the broken line, and the rich mixture operation is performed when the target throttle opening is above the broken line. When the air-fuel ratio is small). At the point B, the air amount is basically kept constant, and only the fuel amount is changed to reduce the air-fuel ratio and increase the engine torque.

In this process, if the air-fuel ratio is reduced with a stratified mixture as shown in FIG. 5 described later, the mixture around the ignition plug becomes too rich, and the mixing state of fuel and air deteriorates. (Phenomenon such as soot occurs), and the engine torque is reduced. Therefore,
Stratification before the mixed state with air deteriorates (indicated by black circles)
Performs uniform switching and suppresses a decrease in engine torque. After switching to the uniform mixture, the state of mixing of air and fuel becomes good, so that it is possible to further increase the fuel amount and increase the engine torque.

When the target throttle opening is fully opened, the air-fuel mixture is shifted to the rich side to achieve both output and engine cooling.

FIG. 4 is a time chart of torque fluctuation suppression at the time of uniform stratification switching, and FIG. 5 is a diagram showing the relationship between the air-fuel ratio and the engine torque. In FIG. 4, when there is no torque fluctuation suppression control (indicated by a broken line), the engine torque decreases even when the switching from the stratified mixture to the homogeneous mixture is successful, as indicated by the thick line in FIG. Fluctuations occur. At this time, the fuel amount is increased until stratification and uniform switching, and is decreased stepwise after the switching. On the other hand, since the air amount changes only gradually from the point of responsiveness, the throttle opening is reduced before the switching (indicated by point a). In addition, c
The area up to the point is the constant air amount area shown in FIG. Therefore, in the present invention, a target torque having no torque fluctuation as shown in FIG. 5 is set, and the engine torque is varied (a in FIG. 4).
The speed ratio is controlled in accordance with the condition (generated between point b and point b). As a result, the torque of the transmission output shaft is proportional to the target torque, and the torque fluctuation can be suppressed. This means that although the engine torque itself fluctuates, the fluctuation of the engine torque is absorbed by the transmission, and as a result, ideal engine torque characteristics are obtained.

However, such a torque variation applies only to the case where switching of uniform stratification is the best, and the switching timing varies due to individual differences of the engine or changes over time, so that further torque variation occurs.

For example, when the switching occurs at the air-fuel ratio indicated by the black circle in FIG. 5, a torque fluctuation between the arrows occurs. In this case, it is necessary to change the speed ratio to the lower side (the side where the reduction ratio is higher). Therefore, in order to perform the best switching, the engine torque is detected using the above-described in-cylinder pressure, a peak of the engine torque in the stratified mixture state is found, and when the peak is changed by an arbitrary air-fuel ratio from this peak, the uniformity is obtained. It is necessary to switch to the mixture.

FIG. 6 is a time chart when the torque fluctuation during the uniform stratification switching is suppressed by the slip control of the lock-up clutch. Here, the fluctuation of the engine torque described with reference to FIG. 4 is suppressed by controlling the slip amount of the lock-up clutch.

The slip amount of the lock-up clutch is increased in accordance with the fluctuation of the engine torque (between the point a and the point b),
A decrease in engine torque can be suppressed by the torque doubling effect of the torque converter. Here, as shown in FIG. 3, the reason why the transmission output torque after point b does not match the engine torque is that the slippage control of the lock-up clutch prevents the engine torque from increasing and generating vibration in the drive train. To do that. As a result, engine torque fluctuation is suppressed, and a feeling of acceleration can be felt.

As described above, while the torque ratio can be suppressed by the gear ratio and the slip control as described above, the engine speed is increased. Therefore, it is desired that the speed change be such that the driver does not feel uncomfortable. Generally, a change in rotation speed of 1000 rpm or less is within the permissible range.

Furthermore, the timing of the uniform stratification switching is near the lean air-fuel ratio at which the homogeneous mixture can be burned and the peak torque during the stratified mixture operation, so that the torque fluctuation suppression control between the air-fuel ratios 18 and 30 is performed. Will be implemented.

Although the method for suppressing the torque fluctuation of the in-cylinder fuel injection engine has been described here, another example is the torque fluctuation at the time of changing the valve timing of the engine.
It can also be applied to the suppression of torque fluctuation when the air conditioner is turned ON / OFF.

FIG. 7 is a diagram showing still another embodiment of the present invention. Here, an example of application to a so-called hybrid vehicle in which a motor is driven by a motor and an engine is shown.

The crankshaft 13 of the engine 1 shown in FIG.
Is provided with a clutch 51 that enables the connection between the drive output shaft 50 and the engine 1 to be released. A gear 52 is attached to the drive output shaft 50 and meshes with a gear 55 attached to a rotation shaft 54 of the motor 53. A charger / controller 57 is provided between the battery 56 and the motor 53, and switches between battery charging and motor control according to the operating state of the engine and the vehicle.

The engine 1 and the motor 53 described above
The actuator for driving is controlled by the controller 58. The controller 58 includes an in-cylinder pressure Pi, a throttle opening θ, a motor speed Ni, an engine speed Ne, an output shaft speed No, an accelerator pedal depression amount α, an air-fuel ratio A / F, an air flow rate Qa, and a manual speed change switch. Ssw is input, and these signals are used for control.

The engine torque control means 33, the engine torque estimating means 35, the torque fluctuation calculating means 36 and the target torque calculating means 37 in the controller 58 execute the same control as described in FIG.

The torque deviation calculated by the calculating means 36 is input to the current value calculating means 59, and the motor torque for suppressing the fluctuation of the engine torque, that is, the current value is obtained. This target current value is input to the current value generating means 60, and controls the control device 57. In the motor control, high-precision torque control is possible, so that good output shaft torque characteristics can be obtained.

FIG. 8 is a time chart of torque fluctuation suppression at the time of uniform stratification switching, and corresponds to FIG. 4 of the above embodiment. In FIG. 8, when there is no torque fluctuation suppression control (indicated by a broken line), even when the switching from the stratified air-fuel mixture to the homogeneous air-fuel mixture is successful, the engine torque is reduced and the engine torque fluctuation occurs. At this time,
The fuel amount is increased until stratification and uniform switching, and is decreased stepwise after switching. On the other hand, since the air amount changes only gradually from the point of responsiveness, the throttle opening is reduced before the switching (indicated by point a). The area from the time of the switching to the point c is a constant air amount area. Therefore, in the present invention, a target torque having no torque fluctuation is set, and the current value of the motor is controlled according to the fluctuation of the engine torque (generated between points a and b in FIG. 8). As a result, the output shaft torque is proportional to the target torque, and the torque fluctuation can be suppressed. This means that although the engine torque itself fluctuates, the fluctuation of the engine torque is absorbed by the motor, and as a result, ideal engine torque characteristics are obtained.

[0065]

In an automobile equipped with a continuously variable automatic transmission, a driver's intention to accelerate is emphasized, and a transmission system in which a continuous gear ratio is set in a stepped manner and used is considered.
In a vehicle equipped with this system, when uniform stratification switching is performed, torque fluctuations are transmitted to the tires, and the driver feels a shock. By recognizing this torque variation and controlling the gear ratio according to the torque deviation at the time of the uniform stratification switching as in the present invention, the shock transmitted to the tire can be suppressed, and the continuously variable automatic transmission as described above The combination of fuel injection and in-cylinder fuel injection makes it possible to achieve both low fuel consumption and good operability.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a torque fluctuation suppression in the in-cylinder fuel injection engine.

FIG. 3 is an engine torque-target throttle opening degree diagram.

FIG. 4 is a time chart of torque fluctuation suppression at the time of uniform stratification switching.

FIG. 5 is a diagram showing the relationship between the air-fuel ratio and the engine torque.

FIG. 6 is a time chart in a case where torque fluctuations at the time of uniform stratification switching are suppressed by slip control of a lock-up clutch.

FIG. 7 is a system configuration diagram of another embodiment.

FIG. 8 is a time chart of torque fluctuation suppression at the time of uniform stratification switching in another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... In-cylinder fuel injection engine, 12 ... Air-fuel ratio detection means, 3
DESCRIPTION OF REFERENCE NUMERALS 1: continuously variable automatic transmission, 34: in-cylinder pressure sensor, 35: engine torque estimating means, 36: torque fluctuation calculating means, 3
7 target torque calculating means 38 speed change ratio calculating means 39
... Pressure adjustment command generation means.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 61/14 601 F16H 61/14 601J // F16H 59:16

Claims (13)

[Claims] 1. A torque fluctuation suppression device for an internal combustion engine having a transmission for adjusting the transmission ratio and transmitting the output of the internal combustion engine to a power transmission system, wherein the amount of intake air supplied to a combustion cylinder of the internal combustion engine An intake air amount control means for controlling a fuel supply timing control means for controlling a supply timing of fuel supplied into a combustion cylinder of the internal combustion engine; and a load applied to the internal combustion engine is predetermined. Control signal output means for outputting a control signal for reducing the intake air amount to the intake air amount control means when the value exceeds the value, the transmission being provided by the control signal or a signal corresponding to the control signal; And a torque fluctuation suppression signal output unit that outputs a torque fluctuation suppression signal that suppresses a torque fluctuation of the internal combustion engine by changing a speed ratio of the internal combustion engine. Wherein the fuel supply timing control means changes the supply timing of the fuel supplied into the combustion cylinder of the internal combustion engine in accordance with the applied torque fluctuation suppression signal. apparatus. 2. The fuel cell system according to claim 1, further comprising fuel amount control means for controlling an amount of fuel supplied to a combustion cylinder of the internal combustion engine by outputting the control signal or a signal corresponding to the control signal. A torque fluctuation suppressing device for an internal combustion engine, characterized in that: 3. The torque fluctuation suppression of an internal combustion engine according to claim 1, further comprising switching means for switching from lockup to slip lockup by output of the control signal or a signal corresponding to the control signal. apparatus. 4. The apparatus according to claim 1, wherein the control signal or a signal corresponding to the control signal is a cylinder pressure signal of a combustion cylinder of the internal combustion engine. 5. The torque fluctuation suppressing device for an internal combustion engine according to claim 1, wherein the control signal or a signal corresponding to the control signal is obtained from an estimated torque value. 6. A torque fluctuation suppressing device for an internal combustion engine having a transmission for adjusting the transmission ratio and transmitting the output of the internal combustion engine to a power transmission system, wherein the relationship between the engine torque or the output torque of the transmission and the transmission ratio. A torque-gear ratio characteristic determining device that determines a torque-gear ratio characteristic by calculation or selects from a stored value, and a detecting unit that detects torque fluctuation of the internal combustion engine; Suppressing means for suppressing the torque fluctuation by changing a speed ratio of the transmission according to a detection signal representing a torque fluctuation detected by the detecting means based on a value determined by the ratio characteristic determining device. A torque fluctuation suppressing device for an internal combustion engine, characterized in that: 7. The system according to claim 6, wherein the detection signal is a valve timing switching signal indicating an opening / closing timing of a valve for supplying intake air supplied to a combustion cylinder of the internal combustion engine. Torque fluctuation suppression device for an internal combustion engine. 8. The torque fluctuation suppression device for an internal combustion engine according to claim 6, wherein the detection signal is an ON / OFF control signal for an air conditioner. 9. The internal combustion engine according to claim 6, wherein the detection signal is supplied around an ignition plug provided in a combustion cylinder of the internal combustion engine when the internal combustion engine receives a load lower than a predetermined load. The intake of the internal combustion engine, which stratifies the combustion chamber so that a mixture of air and fuel is collected, and forms a uniform mixture in the combustion cylinder when the internal combustion engine receives a load higher than the set load. A torque fluctuation suppression device for an internal combustion engine, which is an air amount change signal. 10. The internal combustion engine according to claim 6, wherein the detection signal is supplied around an ignition plug provided in a combustion cylinder of the internal combustion engine when the internal combustion engine receives a load lower than a predetermined load. The intake of the internal combustion engine, which stratifies the combustion chamber so that a mixture of air and fuel is collected, and forms a uniform mixture in the combustion cylinder when the internal combustion engine receives a load higher than the set load. A torque fluctuation suppressing device for an internal combustion engine, which is an estimated torque fluctuation signal accompanying a change in air amount. 11. A torque fluctuation suppression device for an internal combustion engine having a motor for adjusting the motor current and transmitting the output of the internal combustion engine to a power transmission system, wherein the relationship between the engine torque or the output torque of the motor and the motor current is represented. A torque-motor current characteristic determining device for determining a torque-motor current characteristic by calculation or selecting from a stored value; a detecting means for detecting a torque variation of the internal combustion engine; and the torque-motor current characteristic Suppressing means for suppressing the torque fluctuation by changing a motor current of the motor based on a value determined by the determination device in accordance with a detection signal representing a torque fluctuation detected by the detecting means. Torque fluctuation suppression device for an internal combustion engine. 12. The apparatus according to claim 11, wherein the detection signal is a valve timing switching signal indicating an opening / closing timing of a valve for supplying intake air supplied to a combustion cylinder of the internal combustion engine. Torque fluctuation suppression device for an internal combustion engine. 13. The torque fluctuation suppression device for an internal combustion engine according to claim 11, wherein the detection signal is an ON / OFF control signal for an air conditioner.