JPH0970200A - Auxiliary motive power controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary motive power controller for internal combus tion engine which can improve the accelerability of an internal combustion engine and can reduce the exhaust gas emission of the engine. SOLUTION: Since a power control section (torque control means) 3 increases or decreases the torque generated by a generator-motor (torque delivering and receiving means) 2 and the load torque of the generator-motor 2 based on a physical quantity related to the amount of acceleration detected by means of a throttle opening sensor (amount-of-acceleration detecting means) 7 when a discriminated vehicle is accelerated, an auxiliary motive power controller for internal combustion engine which can improve the accelerability of an internal combustion engine and can reduce the exhaust gas emission of the engine can be obtained. Especially, the deterioration of the air-fuel ratio of the engine caused by the response delay of a torque control feedback system can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary power control system equipped with a generator / motor for exchanging torque with an internal combustion engine.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 7-75393 discloses that, in view of an increase in emissions due to a disturbance in the air-fuel ratio during acceleration, an internal combustion engine is operated based on a detected air-fuel ratio (excess air ratio). A range suitable for catalyst purification of the air-fuel ratio (within the window) by variably controlling the amount of torque applied to the engine
It is proposed to reduce the emissions by making them as close as possible.

[0003]

However, in the above-mentioned prior art, since the torque application amount is determined by the air-fuel ratio, the torque application amount changes regardless of the driver's intention and the driving feeling deteriorates. The problem is that the response is inevitably delayed and the transient deterioration of the air-fuel ratio cannot be prevented because the torque application amount is adjusted only after the air-fuel ratio has deteriorated due to fluctuations in driving operation and traveling conditions (for example, traveling load). It is included in.

As an example, the engine intermittently generates torque due to combustion of each cylinder, so even if the accelerator is stepped on during acceleration, the torque does not increase at all until the next cylinder is completely detonated. The pressure in the intake pipe of is shifted to the atmospheric pressure side. When the engine speed increases due to the subsequent explosion, the intake pipe internal pressure rises in the negative direction, and as a result, the intake pipe internal pressure changes like a spike in the initial stage of acceleration. The spike in the intake pipe pressure becomes a disturbance of the air-fuel ratio control of the internal combustion engine, and the air-fuel ratio is greatly disturbed, thereby exceeding the range suitable for catalyst purification and increasing the emission of harmful exhaust gas. On the other hand, since the driver feels that the internal combustion engine has a delayed response, he continues to open the throttle for acceleration, and as a result, the pressure in the intake pipe suddenly rises in the negative direction and exceeds the responsiveness of the air-fuel ratio control. This causes disturbance of the air-fuel ratio and increase of harmful exhaust gas.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide an auxiliary power control device for an internal combustion engine, which is capable of both improving acceleration and reducing exhaust gas emissions. It is an issue.

[0006]

According to a first aspect of the present invention, there is provided:
Torque transmitting / receiving means arranged to transmit / receive torque to / from an internal combustion engine of the vehicle; torque control means for controlling the torque of the torque transmitting / receiving means; and acceleration amount detecting means for detecting a physical quantity related to the acceleration amount of the vehicle. In an auxiliary power control device for an internal combustion engine, the torque control means generates torque of the torque transfer means during acceleration of the vehicle determined based on a physical quantity related to the acceleration amount detected by the acceleration amount detection means. Is an auxiliary power control device for an internal combustion engine, characterized in that the internal combustion engine is increased or the load torque is reduced.

According to this structure, it is possible to realize an auxiliary power control system for an internal combustion engine which is capable of both improving acceleration and reducing exhaust gas emissions. More specifically, in the present configuration, the acceleration amount of the vehicle (the acceleration amount in the present specification means exactly an acceleration amount required in the future, that is, a driver's requested acceleration amount or a desired acceleration amount. ) Is detected, and the amount of torque applied by the generator motor is determined according to the detected acceleration amount. Therefore, it is possible to control the driving torque for traveling that is applied to the traveling drive system faithfully to the driver's intention, and realize an excellent driving feeling without delay in response to the required acceleration amount or the desired acceleration amount instructed by the driver. can do.

Further, the air-fuel ratio depends on the catalyst due to the above-mentioned response delay that has conventionally occurred (for example, the delay in the increase of the traveling drive torque with respect to the increase in the throttle opening and the excessive opening of the throttle opening due to this delay). It is possible to suppress deviation from the range required for exhaust gas purification, and to achieve that, the excellent effect of reducing emissions can be achieved.

Further, by applying the torque, it is possible to suppress the rate of change in fuel supply of the engine, particularly the amount of increase at the time of acceleration, so that the fuel consumption can be improved correspondingly. A second configuration of the present invention is characterized in that, in the first configuration, the torque transfer means is a generator motor.
By doing so, it is possible to apply a torque having a suitable waveform.

A third structure of the present invention is characterized in that, in the first structure, the acceleration amount detecting means further includes a throttle opening degree detecting means for detecting a throttle opening degree. The change in the throttle opening (or the change in the accelerator pedal angle that causes the change in the throttle opening or the change in the intake pipe pressure due to the change in the throttle opening) faithfully indicates the acceleration amount required by the driver. By setting this as the acceleration amount detection physical quantity, the configuration can be easily realized by utilizing the existing control device configuration.

According to a fourth aspect of the present invention, in addition to the second configuration, there is further provided rotation detection means for detecting the rotation speed of the internal combustion engine, and the torque control means is based on the input rotation speed. The torque of the generator motor is increased during acceleration of the vehicle in the determined low rotation range. Since the torque of the generator motor decreases in the high speed range and the air-fuel ratio changes greatly during acceleration in the low speed range, the control operation can be simplified by limiting the control speed range. it can.

A fifth configuration of the present invention further comprises idle detection means for detecting an idle state in the second configuration, wherein the torque control means is configured to generate the power when the vehicle accelerates in the idle state. It is characterized by increasing the torque generated by the electric motor. That is, when accelerating (starting) from the idle state (vehicle stationary state),
Since the largest acceleration amount, that is, the acceleration torque (travel drive torque-travel load torque) is required, if the torque application control of the present invention is executed only during acceleration from this idle time, a great effect can be achieved with a simple configuration. it can.

According to a sixth aspect of the present invention, in addition to the above third aspect, the torque control means generates torque proportional to the product of the input first-order lag component of the throttle opening and the differential term component. The feature is to let. According to this configuration, it is possible to suppress fluctuations in the air-fuel ratio and realize good emission reduction, as will be described later. A seventh configuration of the present invention is the same as the third configuration, further including a fuel supply adjusting unit that adjusts a fuel supply amount based on input information including the throttle opening, and the fuel supply adjusting unit. However, when the vehicle is accelerated, the increase amount of the fuel supply amount is reduced according to the torque amount generated by the generator motor. According to this configuration,
Since the amount of increase in fuel supply is reduced by the amount of torque applied to the generator motor, the traveling drive system transmitted to the vehicle traveling system does not become excessive.

According to an eighth structure of the present invention, in addition to the first structure, the torque transfer means is a compressor with an electromagnetic clutch of a vehicle air conditioner, and the torque control means is the internal combustion engine. It is characterized in that the electromagnetic clutch is opened when acceleration of the vehicle is determined while the compressor is being driven through the electromagnetic clutch.
With this configuration, the same operational effect can be achieved without disposing the generator motor.

A ninth structure of the present invention is further characterized in that, in the first structure, the torque control means applies a substantially rectangular wave voltage to the generator motor during acceleration of the vehicle. . According to the present invention, it is possible to obtain a delay waveform of a current having a large correlation with a current caused by an inductance of a stator winding of a generator motor, and to significantly simplify a control system.

According to a tenth aspect of the present invention, in addition to the ninth configuration, the torque control means determines the torque generation end time point of the generator motor based on the input physical quantity related to the engine speed. It is characterized by doing. With this configuration, the voltage having the substantially rectangular wave shape can be easily determined.

[0017]

【Example】

(Embodiment 1) FIG. 1 shows an embodiment of an auxiliary power control system for an internal combustion engine of the present invention. This auxiliary power control device for an internal combustion engine has both functions of a generator and an electric motor, is connected to a crankshaft of an internal combustion engine 1 of a vehicle so that torque can be transferred, and transfers electric power to and from a power storage means (battery) 6. Two
A power control unit (a part of the torque control means in the present invention) 3 for switching the power generation operation and the electric operation of the generator motor 2 and controlling the output thereof, and throttle opening detection for detecting the acceleration state of the vehicle. Means (acceleration amount detecting means in the present invention) 7, crank angle sensor 4 for detecting the number of revolutions of the internal combustion engine, and power controller 3 based on the signals of the respective sensors to control the operation of generator motor 2. Engine control unit (ECU) 5 (the rest of the torque control means in the present invention)
5

An electrical circuit diagram of this device is shown in FIG. The generator motor 2 is composed of a three-phase synchronous machine, an exciting coil 21 is wound around its rotor core (not shown), and a star-connected three-phase armature coil 22 is wound around its stator core (not shown). It is equipped. The power control unit 3 is a three-phase inverter circuit 3 that is controlled to open and close based on the crank angle.
1 and a transistor 32 for interrupting the exciting current,
The three-phase inverter circuit 31 includes inverters 3u, 3v, 3w for each phase, which are formed by connecting a pair of npn transistors (or IGBTs) in series. Inverters 3u, 3 for each phase
Both ends of v and 3w are connected to both ends of the battery 6, and each transistor (or IGB) of the three-phase inverter circuit 31 is connected.
T) is connected in parallel with the diode and has an inverter 3 for each phase.
Output ends (connection points) of u, 3v, and 3w are connected to the output ends of the three-phase armature coil 22. Excitation coil 21
Is connected to the low end of the battery 6, and the other end is connected to the high end of the battery 6 through the transistor 32.

The power generation operation and the electric operation are switched by controlling the opening / closing timing of each transistor of the three-phase inverter circuit 31 according to a command from the ECU 5, and the energizing duty ratio of the exciting current is controlled by connecting / disconnecting the exciting current controlling transistor 32. However, since the above items are well known, detailed description thereof will be omitted. As a result, the generator motor 2 performs a power generation operation and an electric operation to exchange torque with the internal combustion engine 1 and exchange power with the battery 6.

The acceleration assist subroutine which characterizes this embodiment will be described below with reference to the flow chart of FIG. This subroutine is periodically executed by the ECU 5 under interrupt control. First, the state of an idle switch (not shown) built in the throttle opening sensor 7 is input (step S01), and it is determined whether the idle state or the deceleration state is present (step S01).
03), if the engine is in the idle state or the deceleration state, the process returns to the main routine for engine control (not shown). If not, the engine speed Ne is detected by the engine speed sensor 4 (step S05), and the detected engine speed Ne is detected.
Is less than a predetermined threshold N1 (step S
07).

Explaining the meaning of step S07, since the electric output torque of the generator motor 2 is substantially inversely proportional to its rotation speed, the output torque is small at high rotation, and the effect cannot be expected. Therefore, in step S07, the engine speed Ne is detected, and it is determined whether the electric output torque of the generator motor 2 is less than the sufficiently large low speed region Ne1. N
If e is less than Ne1, the current value θ (i) of the throttle opening is read from the throttle opening sensor 7 (step S09), and the current value θ (i) of the throttle opening and the previous value θ ( It is checked whether the difference θ ′ from i-1) is larger than the predetermined value x. That is, in step S11, it is checked whether the rate of increase in throttle opening is large enough to exceed the predetermined threshold value x, in other words, whether the acceleration amount is sufficiently large. Throttle opening difference θ'is a predetermined value x
If it is larger, it is determined that the torque assist is in a beneficial acceleration state, and the torque application amount of the generator motor is determined in step S.
Proceed to 13.

Before explaining step S13, the torque application of this embodiment will be described with reference to the timing chart of FIG. During normal acceleration, the throttle is opened as shown by the solid line a1 in FIG. 4A, and the intake pipe internal pressure at this time has a spike A and a rapid rising waveform B after that as shown by the solid line b1 in FIG. 4B. It becomes a waveform with. At this time, the torque output from the engine 1 (engine torque) has the characteristics shown by the solid line c1 in FIG.
The rising curve has a response delay (waste time) Δτ.

Here, the ideal output torque (travel drive torque) without the response delay (waste time) is shown by the solid line c3 in FIG. 4 (c), which eliminates the spike in the intake pipe pressure. On the other hand, in order to suppress the sudden increase in the intake pipe pressure indicated by the solid line b1 in FIG. 4B, it is very preferable to slowly open the throttle as indicated by the broken line a2 in FIG. 4A. The change in the intake pipe internal pressure when the throttle is slowly opened in this way is as shown by the broken line b2 in FIG. 4B, and the engine output torque at that time is as shown by the broken line C2 in FIG. 4C.

Therefore, in order to slowly open the throttle as shown by the broken line a2 in FIG. 4 (a) and output the ideal output torque (running drive torque) as shown by the solid line c3 in FIG. 4 (c), It can be seen that the torque difference between the solid line c3 and the broken line C2 of 4 (c) should be given from the generator motor 2. That is, the solid line d in FIG.
It suffices that the generator motor 2 applies the torque of 3 to the engine. At this time, the pressure in the intake pipe of the engine 1 rises slowly as shown by a broken line b2 in FIG. 4B, and does not become a disturbance of the air-fuel ratio control. In other words, the engine output torque is C
If the driver has a good response like 3, then the driver is a1
The accelerator operation such as a2 should be performed without performing the accelerator operation such as the above.

Therefore, in order to realize the torque application in the shape of the solid line d3 in FIG. 4 (d), the signal represented by the product of the differential term component and the first-order lag component of the throttle opening a2 is shown in FIG.
The solid line A1 in (a) is formed. The torque proportional to the solid line A1 has a shape as shown by the solid line B1 in FIG. 5B, and is close to the torque of the above-mentioned broken line d3. A diagram of the torque application control is shown in FIG.

Here, the control signal G represented by the product of the differential term component of the input signal, which is the throttle opening, and the first-order lag component is input to the generator motor 2 as the applied torque amount to be generated. That is, step S13 of the flowchart of FIG.
Then, based on the input throttle opening θ (i), the product of the differential term component and the first-order lag component has a predetermined proportional constant K
_The calculation for obtaining the current value T (i) of the torque application amount T multiplied by ₁ is performed. The present value T of the calculated torque application amount T
(I) is output to the electric power control unit 3, and the electric power control unit 3 controls the generator motor 2 so as to generate the same torque (step S15).

Naturally, during this torque application period, fuel corresponding to the throttle opening a2 should be supplied to the internal combustion engine 1, which means that the amount of increase in fuel during acceleration is reduced as compared with the conventional case. The control result of the embodiment is shown in FIG. As can be seen from FIG. 7, this torque assist control allows
As shown in FIG. 7 (a), the intake pipe pressure gradually rises, and the air-fuel ratio of FIG. 7 (c) has been disturbed in two places, that is, when the intake pipe pressure spike occurs and when it rapidly rises. It was suppressed as shown in FIG. 7 (d), and as a result, the emission amount of harmful exhaust gas could be reduced as shown in FIGS. 7 (e) and 7 (f). (Embodiment 2) Another embodiment will be described with reference to FIG.

First, the idle signal is read (step S01), it is determined whether the idle state or the deceleration state is set (step S03), and if it is the idle state or the deceleration state, the timer is cleared (step S30) and the process returns to the main routine to return to the idle state. If it is not determined that the state or the deceleration state is reached, the process proceeds to step S20. Step S2
At 0, it is checked whether or not the previous value of the idle signal read in step S01 is idle ON. If not, the process proceeds to S30, and the previous value of the idle signal is idle O.
If it is N, it is determined that the vehicle is starting or accelerating from the idle state or the deceleration state, and the process proceeds to step S22. In step S22, the torque application time y is set and the count value COUNT of the timer that counts the elapsed torque application time y is started. It should be noted that the torque application time y is represented by a substantially inverse proportional relationship between the engine speed Ne and the torque application time y shown in FIG.
It is obtained by reading from the table stored in advance in the ROM of CU5. Of course, it is also possible to read from a predetermined storage calculation formula.

In the next step S24, the generator motor is electrically operated to apply torque. In the next step S26, the count value COUNT of the timer is set to the predetermined time y.
It is checked whether it is smaller than the second, that is, whether it is still in the torque applying period, and if it is in the period, step S28
If the period has expired, the process proceeds to step S30. In step S28, if the idle is OFF (when the throttle is open), the process returns to step S24, and the torque application is continued in S24 for the y seconds determined in S26. Then, if the idle is turned off in step S28, the process proceeds to step S30.

In this embodiment, when the process proceeds to step 24 for the first time, the operation of the generator motor 2 as an electric motor is simply turned on. That is, a predetermined three-phase AC voltage that excites the rotation speed is applied to the generator motor 2, and a predetermined exciting current is supplied. At this time, since the generator motor 2 has a large inductance component of the stator winding and the like, the rise and fall of the torque are delayed as shown in FIG. 9, so that the control can be approximated to the control of step S13 of FIG. Therefore, the control operation can be remarkably simplified. Furthermore, this control eliminates the need to detect the accelerator opening, which simplifies the system configuration. (Embodiment 3) As shown in FIG. 1, if the crankshaft of the internal combustion engine 1 is driving the air conditioner compressor 103 through the belt 101 and the electromagnetic clutch 102, as shown in FIG. Instead of step S24 of the flow chart, the electromagnetic clutch may be turned off and the drive of the compressor 103 may be stopped to reduce the load torque. Then, after y seconds, if the electromagnetic clutch 102 is turned on again, the present invention can be implemented even in a vehicle not equipped with a motor generator.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a stop control device for an internal combustion engine of the present invention.

FIG. 2 is an electrical circuit diagram of the device of FIG.

3 is a flow chart showing a control operation of the control device of FIG.
It is.

4A and 4B are diagrams showing a model of a control method of the control device of FIG. 1, where FIG. 4A is a timing chart showing a change in throttle opening and FIG. 4B is a timing chart showing a change in intake pressure. , (C) are timing charts showing changes in output torque, and (d) is a timing chart showing changes in ideal applied torque.

5 is a diagram showing a control method of the control device of FIG.
(A) is a timing chart showing a change in throttle opening, and (b) is a timing chart showing a change in output torque.

FIG. 6 is a control diagram showing the control of FIG.

FIG. 7 is a timing chart showing a control result of this control, (a) is a timing chart showing a change in intake pressure, (b) is a timing chart showing a change in torque, and (c) is a torque chart. It is a timing chart showing an air-fuel ratio change without application, (d) is a timing chart showing an air-fuel ratio change with application of torque, and (e) is a timing chart showing a change in exhaust HC, (F) is a timing chart showing changes in exhausted NOx.

FIG. 8 is a flowchart showing another control operation of the control device of FIG.

FIG. 9 is a timing chart showing torque change characteristics of the generator motor.

[Explanation of Codes] 1 Internal Combustion Engine 2 Generator Motor 3 Electric Power Control Unit (Torque Control Means) 4 Crank Angle Sensor 5 ECU (Torque Control Means) 6 Battery (Power Storage Means) 7 Throttle Opening Sensor (Acceleration Detection Means)

Claims (10)

[Claims] 1. A torque transfer means arranged to transfer torque to and from an internal combustion engine of a vehicle, a torque control means for controlling a torque of the torque transfer means, and an acceleration for detecting a physical quantity related to an acceleration amount of the vehicle. In an auxiliary power control device for an internal combustion engine comprising a quantity detection means, the torque control means, the torque during acceleration of the vehicle determined based on a physical quantity related to the acceleration amount detected by the acceleration amount detection means. An auxiliary power control device for an internal combustion engine, characterized in that the torque generated by the transfer means is increased or the load torque is reduced. 2. The auxiliary power control device according to claim 1, wherein the torque transfer means is a generator motor. 3. The auxiliary power controller according to claim 1, wherein the acceleration amount detecting means includes throttle opening detecting means for detecting a throttle opening. 4. A rotation detection means for detecting the rotation speed of the internal combustion engine, wherein the torque control means is arranged to perform the power generation during acceleration of the vehicle in a low rotation speed range determined based on the input rotation speed. The torque of an electric motor is increased.
An auxiliary power control device for an internal combustion engine as described above. 5. The internal combustion engine according to claim 2, further comprising idle detection means for detecting an idle state, wherein the torque control means increases the torque generated by the generator motor during acceleration of the vehicle in the idle state. Auxiliary power controller. 6. The auxiliary power control system for an internal combustion engine according to claim 3, wherein the torque control means generates a torque proportional to a product of the first-order lag component and the differential term component of the throttle opening input. 7. The internal combustion engine includes fuel supply adjusting means for adjusting a fuel supply amount based on input information including the throttle opening, and the fuel supply adjusting means is configured such that when the vehicle is accelerated, the generator motor is The auxiliary power control system for an internal combustion engine according to claim 3, wherein an increase amount of the fuel supply amount is reduced according to the generated torque amount. 8. The torque transfer means comprises a compressor with an electromagnetic clutch of a vehicle air conditioner, and the torque control means controls the torque control means while the internal combustion engine is driving the compressor through the electromagnetic clutch. The auxiliary power control device for an internal combustion engine according to claim 1, wherein the electromagnetic clutch is released when it is determined that the vehicle is accelerated. 9. The auxiliary power control device for an internal combustion engine according to claim 1, wherein the torque control means applies a voltage having a substantially rectangular wave shape to the generator motor during acceleration of the vehicle. 10. The auxiliary power control device for an internal combustion engine according to claim 9, wherein the torque control means determines a torque generation end point of the generator motor based on a physical quantity related to the input engine speed.