JPH08230520A - Torque shock preventing device for internal combustion engine - Google Patents

Abstract

PURPOSE: To prevent torque shock by performing engine control in a specified time during speed change control when the engine control time coincides with the speed change control time of an automatic transmission. CONSTITUTION: A control circuit 30 is composed of an engine ECU 20 and an electric control transmission electronic controller (ECTECU) 29. The ECTECU 29 controls and automatic transmission according to the traveling condition of a vehicle and detects whether or not it is under the neutral condition during the speed change of the automatic transmission. The engine ECU 20 detects whether it is a time to start the execution of variable cylinder control of the engine or a time to finish the variable cylinder control. When the time coincides with the time of neutral condition, the execution of the variable cylinder control of the engine is started or the variable cylinder control is finished under the neutral condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque shock prevention device for an internal combustion engine, which prevents a torque shock when engine control in which engine torque changes and gear change control compete with each other.

[0002]

2. Description of the Related Art Conventionally, a vehicle control device for performing engine control such that engine torque changes, for example, control of engine combustion state and control of automatic transmission of a vehicle is disclosed in Japanese Patent Laid-Open No. 62-216840. Are known as disclosed in the publication.

By the way, generally, in the control of an automatic transmission, when the shift speed is controlled to be changed on the basis of the shift pattern of the vehicle, the drive torque changes in accordance with the change of the shift speed, resulting in a torque shock. Further, in controlling the combustion state of the engine, for example, when the air-fuel ratio supplied to the engine in the set region is controlled from the lean state to the rich state, torque shock occurs due to a rapid change in the fuel state of the engine. When the shift timing of the automatic transmission coincides with the change timing of the engine control amount, both torque shocks overlap, resulting in a large torque shock as a whole, which deteriorates drivability.

Therefore, in the above-described vehicle control device, when the shift timing of the automatic transmission and the change timing of the engine control amount coincide with each other, by changing either one of them, when the two compete with each other. It is designed to prevent the torque shock of.

[0005]

However, in the above-mentioned prior art, the shift or the engine control is delayed during the transient operation, which may cause the following problems. If the speed change control is delayed, the engine speed will exceed the permissible engine speed, engine overrun will occur, the feeling of acceleration will deteriorate due to the delay in kickdown during acceleration, and the speed will change due to the delay in upshifting when the accelerator pedal is released from acceleration. There may be a feeling of discomfort due to delay.

Further, when the engine transient control is delayed, the air-fuel ratio becomes rough at the time of transient, and problems such as breathing and rattling occur due to abnormal combustion such as misfire and knock. An object of the present invention is to perform engine control at a specific time during shift control when the engine control timing and the shift control timing of the automatic transmission match when performing engine control such that the engine torque changes. An object of the present invention is to provide a torque shock prevention device for an internal combustion engine that can prevent torque shock.

[0007]

In order to solve the above problems, the present invention provides a transmission control means for controlling an automatic transmission according to a running state of a vehicle, and a neutral state during shifting of the automatic transmission. Neutral state timing detection means for detecting whether or not the internal state of the internal combustion engine is controlled by the internal combustion engine control means for controlling the engine control such that the engine torque of the internal combustion engine changes according to the operating state, and the control timing of the engine control by the internal combustion engine control means. And an internal combustion engine control timing detection means for detecting the torque shock of the internal combustion engine that performs engine control when the internal combustion engine control timing matches the neutral state timing. The gist is the prevention device.

[0008]

With the above structure, the transmission control means controls the automatic transmission according to the running state of the vehicle. The neutral state timing detection means detects whether or not the automatic transmission is in a neutral state during shifting. The internal combustion engine control timing detection means detects the control timing of engine control by the internal combustion engine control means.

In controlling the engine control of the internal combustion engine in accordance with the operating state, the internal combustion engine control means performs the engine control when the internal combustion engine control timing coincides with the neutral state timing.

[0010]

EXAMPLES The present invention will now be described with reference to a V-type 8 capable of variable cylinder operation.
An embodiment embodied in a cylinder gasoline engine will be described with reference to FIGS.

As shown in FIG. 1, the engine 1 has 4 cylinders in each bank, that is, 8 cylinders # 1 to 8 in total.
# 8 is provided. Each cylinder # 1 for each bank
An intake passage 2 forming a part of the intake system and an exhaust passage 3 forming a part of the exhaust system are provided in # 4, # 5 to # 8. In the engine 1 in the all-cylinder operating state, a mixture of intake air taken into each intake passage 2 and fuel injected from the injectors 4a to 4h is supplied to each cylinder # 1 to # 8. Engine 1 cylinders #
An ignition plug 5 is provided in each of 1 to # 8, and the ignition voltage distributed by the distributor 6 is applied to the ignition plug 5 in the all-cylinder operating state. Further, in the variable cylinder operating state, the engine ECU 20 described later controls the fuel of only the injectors 4a to 4d on the one bank side and stops the fuel supply to the other injectors 4e to 4h. Further, in the variable cylinder operating state, the engine ECU 20 described later controls the application of the ignition voltage only to the ignition plug 5 on the one bank side.

The distributor 6 is an igniter 7
It is for distributing the high voltage output from each ignition plug 5 in synchronization with the crank angle, and the ignition timing of each ignition plug 5 is determined by the high voltage output timing from the igniter 7. Then, the engine 1 explodes the air-fuel mixture in each of the cylinders # 1 to # 8 by the spark plug 5 to obtain a driving force, and then discharges the exhaust gas from the exhaust passage 3.

A surge tank 8 for suppressing intake air pulsation is provided on the upstream side of the intake passage 2. On the upstream side of the surge tank 8, there is provided a throttle valve 9 which is opened / closed in conjunction with the operation of an accelerator pedal (not shown). By opening / closing the throttle valve 9, the intake passage 2 is opened.
The intake air amount to the air is adjusted.

A throttle opening sensor 10 for detecting the throttle opening T is provided near the throttle valve 9. Further, on the upstream side of the throttle valve 9, an air flow meter 11 and an air cleaner 12 as an intake amount sensor for detecting the intake air amount are arranged. The air flow meter 11 outputs an air flow meter signal Q which is a detection signal of the intake air amount. In this embodiment, the air flow meter 11 is used as the intake amount sensor, but a Kalman type intake amount sensor may be used instead.

On the other hand, the exhaust passage 3 is composed of a first exhaust passage 13a and a second exhaust passage 13b.
3a is connected to the cylinders # 1 to # 4 of the engine 1, and the second exhaust passage 13b is connected to the cylinders # 5 to # 8 of the engine 1. The first exhaust passage 13a and the second exhaust passage 13b are connected to the downstream side.

Further, in this embodiment, the engine 1 is connected to an overdrive four-speed automatic transmission 14 with a direct coupling clutch for switching the speed change state. The automatic transmission 14 is provided with an engine speed sensor 15, a transmission input speed sensor 16, and a transmission output speed sensor 17, respectively. The engine speed sensor 16 is
The rotation speed N1 of the gear on the output shaft 1a side of the engine of the automatic transmission 14 is detected. The transmission input rotation speed sensor 16 is
The rotation speed N2 of the gear on the output shaft 18a (transmission mechanism input shaft) side of the torque converter 18 provided in the automatic transmission 14
(Transmission input shaft speed) is detected. The transmission input rotation speed sensor 17 detects the rotation speed N3 (gear of the transmission output shaft) of the gear on the output shaft 14a side of the automatic transmission 14.
The throttle opening sensor 10 and the transmission output rotation speed sensor 17 constitute a traveling state detecting means.
The air flow meter 11 and the engine speed sensor 15
Constitutes an engine operating state detecting means.

Further, the engine 1 is provided with a switching mechanism 19 for switching the number of operating cylinders (see FIG. 2).
The switching mechanism 19 includes intake-side and exhaust-side camshafts (not shown) rotatably supported by the cylinder head, and these camshafts are connected and driven by the crankshaft of the engine 1 via a timing belt. The camshaft is provided with a cam having two types of cam profiles in the axial direction, and when the camshaft moves in the axial direction by an actuator (not shown), the cam profiles are switched. By this switching, the intake and exhaust valves of the cylinder of one bank are switched between the openable and closable states and the closed state, and all cylinders are in the operating state and only the cylinders # 1 to # 4 on one bank side are operating. The variable cylinder operating state is switched.

Next, the control circuit 30 will be described. The control circuit 30 includes an engine ECU 20 as an internal combustion engine control means and an internal combustion engine control timing detection means, and an electric control transmission electronic control device (E) as a transmission control means and a neutral state timing detection means.
CTECU) 29.

The engine ECU 20 will be described with reference to the block diagram of FIG. The engine ECU 20 includes a central processing unit (CPU) 21, a read-only memory (ROM) 22 in which a predetermined control program and the like are stored in advance, and a random access memory (RA) in which the calculation result of the CPU 21 is temporarily stored.
M) 23, each of these units, the input / output port 24, the A / D converter 25, and the external output circuit 26 are connected by a bus 27 as a logical operation circuit.

The engine speed sensor 15, the transmission input speed sensor 16, and the transmission output speed sensor 17 are connected to the input / output port 24, respectively. A / D
An air flow meter 11 and a throttle opening sensor 10 are connected to the converter 25. On the other hand, the external output circuit 2
The injectors 4a to 4h and the igniter 7 are connected to the injector 6, respectively.

Then, the CPU 21 reads the detection signals of the sensors 15 to 17 and the like, which are input via the input / output port 24, as input values. Further, the CPU 21 outputs from the air flow meter 11 and the throttle opening sensor 10,
A detection signal converted from an analog value to a digital value by the A / D converter 25 is read as an input value. Also, CPU2
Reference numeral 1 denotes injectors 4a to 4a for executing fuel injection amount control, ignition timing control, variable cylinder control, etc. on the basis of input values read from the respective sensors 10, 11, 15 to 17.
The h, the igniter 7, etc. are preferably controlled.

As described above, the engine ECU 20 is a device that controls fuel injection amount control, ignition timing control, variable cylinder control, and the like. Next, the ECT ECU 29 will be described.

The ECT ECU 29 controls the direct coupling clutch control and shift control in the automatic transmission 14. Therefore, a shift position sensor 28, which is provided in the gear shift mechanism of the automatic transmission 14 and detects the shift position thereof, is electrically connected to the input side of the ECT ECU 29. An actuator 31 built into the automatic transmission 14 is electrically connected to the output side of the ECT ECU 29. The actuator 31 controls the gear shift mechanism of the automatic transmission 14 based on the shift control signal output from the ECT ECU 29.

Further, the ECT ECU 29 is an engine EC
Data signals are exchanged with the U20 via the input / output port 24. And ECTE
The CU 29 reads input signals from various sensors and data signals such as calculation results from the engine ECU 20, reads the detection values from the shift position sensor 28, and suitably controls the automatic transmission 14 in accordance with the shifting conditions at that time. A shift-up pattern is selected from a ROM (not shown) depending on the state of the shift position, and the throttle opening and the engine speed N at that time are selected based on the determined pattern.
The gear shift operation is performed according to 1 (vehicle speed). In addition, this ECT
Although not shown, the ECU 29 is also configured as a logical operation circuit including a central processing unit (CPU), ROM, RAM and the like like the engine ECU 20.

Now, the operation of the embodiment constructed as described above will be described. 3 and 4 show a gear shift control routine, in which the ECT ECU 29 executes the routine at regular time intervals. Before entering this control routine, these input values are stored in the RAM of each of the ECUs 20 and 29 based on the detection signals from various sensors that are input at each time.

In step 101 (hereinafter, step is referred to as S), throttle opening T and transmission output shaft speed N3
(Corresponding to the vehicle speed) is read, and then, in S102, the shift position Sm corresponding to the throttle opening T and the transmission output shaft speed N3 is calculated by the shift pattern map stored in the ROM. S102 constitutes a shift position calculating means. Next, in S103, the current ECTE
The shift position Sn controlled by the CU 29 is read from the RAM. In S104, the shift position Sm and the shift position Sn are compared, and if they are the same, it is determined that there is no shift request, and the process proceeds to S114 described later. Step S104 constitutes a shift start detecting means.

If the shift position Sm is different from the shift position Sn in S104, it is determined that there is a shift request, and the shift start flag F1 is set in S105. In S106, the current transmission input shaft rotation speed is set. N
Read in 2. Next, in S107, the shift position S
The transmission input shaft speed in m is calculated from the gear ratio of the transmission and is set to N2m. In S108, the shift position S
The transmission input shaft speed at n is calculated from the gear ratio of the transmission and is set to N2n. That is, the transmission rotation speed before and after the shift is calculated in both steps. The gear ratio is stored in the ROM 22 in advance. S107 and S1
Reference numeral 08 constitutes a neutral detection parameter calculation means.

Next, in S109, the shift position Sm
> Whether the shift position is Sn or not, that is, whether the shift is up or down is determined. The step S109 constitutes a shift position determining means. If shift position Sm> shift position Sn, shift up (transmission input shaft speed N2
Is determined), and in S110, N2 ≤ N2n x C
It is determined whether or not 1, and in S111 N2 ≤
It is determined whether N2m × C2. That is, S110 and S
In 111, when the transmission input shaft rotational speed N2 is apart from N2m and N2n before and after the shift by predetermined widths C1 and C2, it is determined that the neutral state is established. In this embodiment, N before and after shifting
C1 is set to 0.9 and C2 is set to 1.1 in order to determine that it is neutral when it is separated from 2 m and N2n by 10% or more. Then, in S110, it is judged to be neutral when the transmission input shaft rotation speed N2 decreases and becomes "N2n × 0.9" or less in S110, and in S111,
The transmission input shaft speed N2 further decreases and N2m
When "N2m × 1.1" or less is reached, it is determined that the shift is completed.

Therefore, in S110, N2> N2n
In the case of × C1, it means that the shift has just been started, and therefore the process proceeds to S114 described later. Also, in S111, N2n × C
If 1 ≧ N2> N2m × C2, it is determined that the vehicle is in the neutral state, and gear shifting is in progress in S117 (transient control of engine 1 is permitted).
Flag F2 is set, the gear shift start flag F1 is cleared in the next step S118, and the process proceeds to step S114. On the other hand, S1
In N11, if N2 ≤ N2m x C2, it is determined that the shift is completed, Sm is stored in the current shift position in S112, the shift flag is cleared in the next S113, and the neutral state detection is finished. Then, the process proceeds to S114. In S114, the transmission is controlled in advance to operate the actuator 31 based on the control program, and this routine is exited.

If Sm <Sn in S109, it is determined that the shift is down (the transmission input shaft speed N2 is increased), and in S115 and S116, S11 is selected.
In step S5, it is determined whether N2 ≧ N2n × C3, and in step S116, it is determined whether N2 ≧ N2m × C4. That is, in S115 and S116, when the transmission input shaft rotation speed N2 is apart from N2m and N2n before and after the shift by the predetermined widths C3 and C4, it is determined to be in the neutral state. In this embodiment, C3 is set to 1.1 in order to determine that it is neutral when it is 10% or more away from N2m and N2n before and after shifting.
And C4 is set to 0.9. Then, in S115, the transmission is started and the transmission input shaft speed N2 rises, and it is judged to be neutral when "N2n × 1.1" or more is reached. In S116, the transmission input shaft speed N2 is determined.
Further increases and approaches N2m after shifting, and “N2m × 0.
When it is 9 "or more, it is determined that the shift is completed.

Therefore, in S115, N2 <N2n
In the case of × C3, it means that S1
Move to 14. Further, in S116, N2n × C3 ≦
If N2 <N2m × C4, it is determined that the vehicle is in the neutral state, the flag F2 during shifting (permitting transient control of the engine 1) is set in step S117, the shifting start flag F1 is cleared in step S118, and the processing proceeds to step S114. To do. On the other hand, S11
In N6, if N2≥N2m * C2, it is determined that the shift is completed, Sm is stored in the current shift position in S112, the shifting flag is cleared in S113, and the neutral state detection is finished.

The same applies to the following when downshifting.
At 114, transmission control is performed. S110, S
Reference numeral 111 constitutes a first neutral state timing detection means at the time of shift up, and S115 and S116 constitute a second neutral state timing detection means at the time of shift down. And S110, S111, S11
5, S116 constitutes a neutral state timing detecting means during shifting of the automatic transmission.

Next, the engine control will be described. 5 and 6 show a variable cylinder control routine of the engine 1. The engine ECU 20 executes the routine at regular time intervals. It should be noted that before entering this control routine, E is detected based on detection signals from various sensors that are input at each time.
The RAM of the CU is stored as these input values.

When this routine is entered, in step S201, the variable cylinder execution flag F3 indicating whether or not the variable cylinder is currently being executed is read. Next, in S202, the air flow meter signal Q and the engine speed N1 are read, and S20
3, in S204, the execution condition of the variable cylinder is checked based on the air flow meter signal Q and the engine speed N1. If the execution condition is satisfied, it is determined in S205 whether or not the variable cylinder in-execution flag F3 is set. When the variable cylinder in-execution flag F3 is set, that is, when the variable cylinder control is currently being performed, the control is ended as it is, and this routine is exited.

If the variable cylinder in-execution flag F3 is 0 in S205, the gear shift start flag F1 is checked in S206. If the gear shift start flag F1 is set, it is assumed that the gear shift has just started, and the control waits until it becomes neutral.
Get out of this routine. If the shift start flag F1 has been cleared, it is checked in S207 with the shift-in-progress flag F2 whether the neutral state or not. S207
If the in-shift flag F2 is set (in the neutral state), the immediate variable cylinder control is executed in S208. That is, the switching mechanism 19
A control signal is output to and the cam shaft is moved in the axial direction by an actuator (not shown) to switch the cam profile. By this switching, the intake and exhaust valves of the cylinders # 5 to # 8 of one bank are kept closed, and the injectors 4e to # 8 of the cylinders # 5 to # 8 are closed.
Cylinder # 1 on one bank side after fuel cut to 4h
The variable cylinder operating state in which only # 4 is operated is set.

On the contrary, in S207, the in-shift flag F
If 2 is 0, a shock countermeasure such as switching smoothing processing is set in S210, and the process proceeds to S208. After that, in S209, the variable cylinder flag F3
To exit this control routine.

Therefore, in S205 to S208, the execution steps in starting the control of the variable cylinder are represented,
The variable cylinder control is realized when it is determined in S207 that the shift state is neutral.

On the other hand, in S204, the execution condition of the variable cylinder is checked based on the air flow meter signal Q and the engine speed N1. If the execution condition is not satisfied, the process proceeds to S211.

If the variable cylinder execution flag F3 is 1 in S211, the gear shift start flag F1 is checked in S212. If the gear shift start flag F1 is set, it is assumed that the gear shift has just started, and the control waits until it becomes neutral.
Get out of this routine. If the shift start flag F1 is cleared, it is checked in S213 whether or not the neutral state is established by the shift in progress flag F2. S213
If the in-shift flag F2 is set (in the neutral state), the variable cylinder is immediately ended in S214.

That is, a control signal is output to the switching mechanism 19 and the cam shaft is axially moved by an actuator (not shown) to switch the cam profile.
By this switching, the intake and exhaust valves of the cylinders # 1 to # 8 of both banks can be opened and closed, and the cylinders # 1 to # 8 of both banks are operated in the all-cylinder operating state.

On the contrary, in S213, the shifting flag F
If 2 is 0, in S216, shock countermeasures such as the smoothing process at the end are set, and the process proceeds to S214. Then, in S215, the variable cylinder flag F3
To clear this control routine.

Therefore, in S211 to S214 described above, the execution steps at the end of control of the variable cylinder are represented,
The termination of the variable cylinder control is realized when it is determined in S213 that the shift state is neutral.

The above S204 to S207 and S211 to S
Reference numeral 213 constitutes an internal combustion engine control timing detecting means. FIG. 7 shows a time chart when the variable cylinder control is executed according to the above control routine, particularly when downshifting is executed.

In this figure, the shift position from the shift pattern is changed at the time of T1, and at the same time, the shift start flag F1 becomes 1
Is set to Then, after the lapse of T1 and before the time T2, the variable cylinder control execution condition becomes not satisfied, and T
When the transmission input shaft rotation speed N2 exceeds “N2n × C3” at 2 o'clock, the gear shift start flag F1 is cleared to 0 and the gear shift flag F2 is set to 1. That is,
After T2, the transmission 14 is in the neutral state. In this neutral state, the fuel cut of the injectors 4e to 4h in the cylinders # 5 to # 8 of one bank is gradually restored. Further, in the neutral state, the variable cylinder executing flag F3 is cleared to 0.

At T3, the transmission input shaft speed N2 is "N2m
When "C4" is exceeded, the shifting flag F2 is set to zero. That is, after T3, the transmission 14 is in a state where the neutral state has ended.

As described above, in this embodiment, during the shift of the automatic transmission 14, the variable cylinder control is started or ended when the automatic transmission 14 is in the neutral state. When the automatic transmission 14 is in the neutral state, the engine torque is not transferred between the two clutches, so that the torque change is interrupted during engine control, that is, when the variable cylinder control is started or ended. It can be prevented. Further, since the shift control timing is not delayed with respect to the engine control (variable cylinder control start or variable cylinder control end) timing, engine overrun does not occur, and the shift delay does not feel uncomfortable.

The present invention is not limited to the above embodiment, but may be realized as follows. (A) In the embodiment, the variable cylinder control is started or the variable cylinder control is ended as the transient control of the engine. However, when the air-fuel ratio control is performed, the automatic transmission during the shift control of the air-fuel ratio control is performed. It may be performed in the neutral state of.

Based on the above-mentioned embodiment, the technical idea grasped other than the claims described in the scope of claims will be described together with its effects. (1) The internal combustion engine is a variable cylinder type, and the internal combustion engine control means performs all-cylinder control or variable cylinder control of the internal combustion engine according to an engine operating state. Torque shock prevention device. According to this configuration, the torque change is blocked during the internal combustion engine control, that is, when the variable cylinder control starts or when the variable cylinder control ends, so that the torque shock can be prevented.

[0049]

As described in detail above, according to the present invention,
When performing engine control such that the engine torque changes,
When the engine control timing coincides with the shift control timing of the automatic transmission, torque shock can be prevented by performing the engine control at a specific timing during the shift control.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an electric block diagram of the same.

FIG. 3 is a flowchart of shift control.

FIG. 4 is a flow chart of shift control.

FIG. 5 is a flowchart of engine control.

FIG. 6 is a flowchart of engine control.

FIG. 7 is a time chart.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 4a-4h ... Injector, 5 ... Spark plug, 10 ... Throttle opening sensor, 11 ... Air flow meter, 14 ... Automatic transmission, 15 ... Engine speed sensor, 16 ... Transmission input shaft speed sensor, 17 ... Transmission output shaft speed sensor, 20 ... Engine ECU as internal combustion engine control means and internal combustion engine control timing detection means, 21 ... C
PU, 28 ... Shift position sensor, 29 ... ECTEC as transmission control means and neutral state timing detection means
U, 30 ... Control circuit.

Claims (1)

[Claims] 1. A transmission control means for controlling an automatic transmission according to a running state of a vehicle, a neutral state timing detecting means for detecting whether or not the automatic transmission is in a neutral state during shifting, and an internal combustion engine The internal combustion engine control means for controlling the engine control such that the engine torque changes according to the operating state; and the internal combustion engine control timing detection means for detecting the control timing of the engine control by the internal combustion engine control means, A torque shock prevention device for an internal combustion engine, wherein when the engine control timing coincides with the neutral state timing, the internal combustion engine control means performs the engine control in the neutral state.