JPH04314633A - Control device for engine - Google Patents

Abstract

PURPOSE:To reduce an unnecessary slip eliminated in each friction element by suitably controlling resetting engine output torque in accordance with a line pressure of an automatic transmission when a speed change is finished. CONSTITUTION:In an automatic transmission Z, a torque reducing means 22 and a line pressure reducing means SOL6 are actuated at speed change time. When a speed change is finished, a line pressure resetting means 50 resets a line pressure by stopping action of the line pressure reducing means SOL6. The line pressure at this time of starting the line pressure reset is detected by a line pressure detecting means 33, and its detection output is given to a torque reset timing setting means 52. In this timing setting means 52, the higher is the line pressure at the time of starting the line pressure reset the earlier torque reset start timing, stopping action of the torque reducing means 22 after starting the line pressure reset, is set. In this way, a speed change shock can be effectively reduced, further an unnecessary slip of a friction element in the transmission 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 improvement in an engine control device for controlling the output torque of an engine during gear changes in an automatic transmission.

0002

2. Description of the Related Art Conventionally, as a control device for this type of engine, for example, as disclosed in Japanese Patent Application Laid-Open No. 56-96129, an input shaft of an automatic transmission is connected to an output shaft of an engine. There is a known automatic transmission that effectively reduces shift shock by controlling to reduce the torque generated by the engine in accordance with the up-shift operation of the automatic transmission.

0003

By the way, in order to more effectively reduce the shift shock, in addition to the torque reduction control described above, it is necessary to control the line pressure of the hydraulic control circuit of the automatic transmission to a low level. It is conceivable to slowly tighten the friction elements.

However, in this case, when the engine generated torque and line pressure are returned to their normal values at the end of the gear shift, if the restoration of both is started at the same time,
Because the responsiveness of the return of the engine's output torque is fast, when the line pressure has not returned sufficiently, the engagement force of each friction element of the automatic transmission is insufficient, and a large value of engine torque is applied. Unnecessary slipping occurs in each friction element, which impairs its durability and reliability.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a method for reducing the output torque of the engine and the line pressure of the automatic transmission at the time of shifting. Sometimes, the restoration of the output torque of the engine is appropriately controlled depending on the line pressure value of the automatic transmission to reduce or eliminate unnecessary slippage of each friction element.

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, at the end of a shift, the output torque of the engine is restored with a delay after the line pressure starts to return, and the timing of the return of the output torque is set to the line pressure. , the return speed of the line pressure, or the magnitude of the output torque of the engine.

[0007] In other words, the specific solution of the invention as claimed in claim 1 is as shown in FIG.
In the engine 1 to which the input shaft of the engine 1 is connected,
A torque reducing means 22 for reducing the output torque of the automatic transmission Z, and a line pressure reducing means SOL6 for reducing the line pressure of the hydraulic control circuit of the automatic transmission Z. Line pressure reduction means SO
The target is an engine control device that operates L6. and a line pressure return means 50 for stopping the operation of the line pressure reducing means SOL6 and restoring the line pressure at the end of the shift of the automatic transmission Z;
a line pressure detection means 33 for detecting the line pressure at the time when the line pressure starts returning due to zero, and the line pressure detection means 33
A torque return timing setting means 52 is provided which receives the output of the line pressure and sets the torque return start timing earlier to stop the operation of the torque reduction means 22 after the line pressure return starts, the higher the line pressure at the time of the line pressure return start. It is structured as follows.

In addition to the configuration of the invention as claimed in claim 1, the specific solution of the invention as claimed in claim 2 is, as shown by the broken line in the same figure, the restoration of line pressure by line pressure restoration means 50. A return speed detection means 51 for detecting the speed is provided, and a torque return timing setting means 52 is configured to set the torque return start timing earlier as the line pressure return speed detected by the return speed detection means 51 is faster. ing.

[0009] Furthermore, the specific solution of the invention as claimed in claim 3 includes, in addition to the structure of the invention as claimed in claim 1, torque detection means 24 for detecting engine torque, as shown by a broken line in the figure. In addition, the torque return timing setting means 52 is configured to set the torque return start timing later as the engine torque detected by the torque detection means 24 increases.

0010

[Operation] With the above configuration, in the invention as claimed in claim 1,
During gear shifting, the line pressure is reduced and the friction elements are engaged more slowly, and the output torque of the engine is reduced, so that both effectively reduce the gear shifting shock.

[0011] Furthermore, line pressure restoration control is started at the end of the gear shift, and after that, engine output torque restoration control is started with a delay. In this case, when the line pressure value at the end of the shift is high, the engagement force of each friction element of the automatic transmission Z is stronger than when the line pressure is low, so the above-mentioned output torque return control is performed. Even if done early, unnecessary slipping of the friction elements can be prevented.

[0012] Furthermore, in the invention as claimed in claim 2, when the return speed of the line pressure is fast, the engagement force of each friction element of the automatic transmission Z increases quickly, so that the engine 1
Even if the start timing of the return control of the output torque becomes earlier, unnecessary slipping of the friction element can be effectively prevented.
The engine's output torque is quickly increased to improve the running performance of the vehicle.

Furthermore, in the invention as set forth in claim 3, when the output torque of the engine is large, slippage is likely to occur in each friction element of the automatic transmission Z. During the time when the timing is set late and the start timing of the torque return control is delayed, the line pressure of the automatic transmission Z increases and the engagement force of the friction element increases. Slippage is effectively prevented.

[0014]

[Effect of the invention] As explained above, claim 1 of the present application
According to the engine control device according to claims 2 and 3, when both the engine output torque reduction control and the automatic transmission line pressure reduction control are performed during a gear shift, the line pressure is reduced at the end of the gear shift. The pressure reduction control is stopped immediately, the engine output torque reduction control is stopped after a delay, and the return timing of this output torque is set to be earlier as the line pressure is higher, effectively reducing shift shock. At the same time, it suppresses unnecessary slippage of the friction elements of automatic transmissions,
Its durability and reliability can be improved.

In particular, according to the invention as claimed in claim 2, when the engagement force of the friction element increases quickly after the end of the gear shift, the output torque of the engine can be quickly increased in accordance with this, so that the above effect can be achieved. In addition, it is possible to prevent the engine output from increasing slowly immediately after the end of the shift, thereby improving driving performance.

Furthermore, according to the third aspect of the present invention, when the engine torque at the end of the gear shift is large, the engine torque starts to rise again when the engagement force of the friction element increases sufficiently, so that the friction is further reduced. Unnecessary slippage of elements can be suppressed or eliminated.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to FIG. 2 and the following drawings. In Fig. 2, 1 is a V-type engine, and left and right banks 1a and 1b are provided with a combustion chamber 4 whose volume is variable by a piston 3 fitted into a cylinder 2 inclined at a predetermined angle. There is. Each combustion chamber 4
are respectively independent intake passages 5a and 5b, and one collective intake passage 5c in which these two passages are joined at their upstream ends.
It is communicated with the atmosphere through the exhaust passage 6, and is also opened to the atmosphere through the exhaust passage 6. Each of the independent intake passages 5a, 5b is provided with a throttle valve 7 near its upstream end for adjusting the amount of intake air.
A fuel injection valve 8 for injecting and supplying fuel is provided on the downstream side. Reference numeral 10 denotes an idle speed adjustment device that adjusts the amount of bypass intake air in the intake bypass passage 11 that bypasses the throttle valve 7 to set the idle speed of the engine 1 to a target value.

Reference numeral 12 denotes an opening sensor for detecting the opening of the throttle valve 7, and the throttle valve opening signal is input to a control unit 20 having a CPU and the like therein. Furthermore, the control unit 20 includes crank angle and engine speed signals detected by a crank angle sensor 13 provided in the distributor 19, an intake air temperature signal on the upstream side of the throttle valve 7 detected by an intake air temperature sensor 14, and an air flow sensor. 15, the intake air temperature signal on the downstream side of the throttle valve 7 detected by the intake air temperature sensor 16, the engine coolant temperature signal detected by the water temperature sensor 17, and the air-fuel ratio signal of the mixture detected by the O2 sensor 18. , and an engine torque signal from a torque sensor 24 serving as a torque detection means for detecting the output torque of the engine 1 arranged near the output shaft of the engine 1. The control unit 20 also controls the idle adjustment valve 21 of the idle speed adjustment device 10, and reduces the amount of fuel injected from the fuel injection valves 8, 8 from the normal value to increase the output torque of the engine 1. The torque reducing means 22 is configured to reduce the torque. Note that a catalytic converter 23 is disposed in common in both exhaust passages 6.

Further, in FIG. 3, Z is an automatic transmission whose input shaft is connected to the output shaft of the engine 1,
Although not shown, it is equipped with a torque converter, a multi-stage planetary gear mechanism, and a lock-up clutch inside, and also includes a lock-up solenoid SOL-1 and a lock-up release solenoid SOL-2 that engage and release the lock-up clutch, and the planetary gear mechanism described above. Three speed change solenoids SOL-3 to SOL-5 that engage and disengage the various friction elements of the gear mechanism and the above-mentioned lock-up clutch, respectively.
and a line pressure solenoid SOL-6 for adjusting the line pressure of the hydraulic control circuit in the transmission, and the line pressure solenoid SOL-6 for adjusting the line pressure constitutes a line pressure reducing means for reducing the line pressure. ing.

Furthermore, in FIG. 3, 29 is a vehicle speed sensor that detects the vehicle speed, and 30 is a torque converter of the automatic transmission Z.
31 is a torque sensor that detects the output torque of the output shaft Za of the automatic transmission Z; 32 is a line pressure detection means that detects the line pressure of the automatic transmission Z; This is an oil pressure sensor. Also, 33
34 is a power mode selection switch that selects a mode that prioritizes driving performance with a sense of acceleration (power mode), and 34 is an economy mode that selects a mode that prioritizes economical driving (economy mode). The selection switch 35 is the starter switch for the engine 1, and 36 is the range position selected by the select lever of the automatic transmission Z, that is, D (automatic transmission up to 4th speed), N (neutral), R. ( Recession)
, S (automatic shift up to 3rd speed), and L (automatic shift up to 2nd speed);
7 is a stop lamp switch that detects when the brake pedal is depressed, 38 is a power steering switch that detects when the power steering device is activated, 39 is an air conditioner switch that detects when the in-vehicle air conditioner is activated, 40 is lights, etc. This is an electrical load switch that detects when an electrical load is activated. And each of the above-mentioned sensors and switches 29 to 40
and an inhibitor signal as an engine no-load signal are input to the control unit 20.

Next, the cooperative control of the automatic transmission Z and the engine 1 during gear shifting by the control unit 20 will be explained based on the control flows shown in FIGS. 4 to 6.

In FIG. 4, the system is reset and started when the power is turned on, and after initializing various data in step Sa1, time synchronization is set every 25 msec, for example, in order to process at a set cycle in step Sa2. It is determined whether the flag is set, and only if it is set, the signals from various sensors and switches are processed in step Sa3, and the end of the shift is determined by the shift solenoid S in step Sa4.
Judgment is made based on the output signals to OL-3 to SOL-5. After that, in step Sa5, learning control is performed so that the line pressure at the next gear shift is a low appropriate value that does not cause a shift shock, and at the next gear shift, the line pressure adjustment solenoid SOL-6 is controlled to The line pressure is reduced based on the learned value, and when the end of the shift is detected, the control of the line pressure adjustment solenoid SOL-6 is stopped to raise and return the line pressure. It functions as a return means 50.

[0023] Next, in step Sa6, the engine torque is controlled by learning so that the engine torque at the next gear change will not cause a shift shock, and in step Sa7, the line pressure and engine torque are controlled to be the learning-controlled line pressure and engine torque at the next gear change. Then, the output process is performed and the process returns to step Sa1.

The control flow shown in FIG. 5 is a control flow for calculating the speed at which the line pressure returns after the end of the shift and calculating the line pressure value at which to start the control for restoring the output torque of the engine.

In the figure, starting from step S
Figure 7 (a) starts after line pressure recovery control is started at b1.
), it is determined whether or not the set time ts has elapsed, and only when it has elapsed, in step Sb2, the average recovery speed of the line pressure within the above period ts is determined based on the line pressure signal of the oil pressure sensor 32. At the same time as calculating step S
In b3, the return time tq required for the engine torque to return to its normal value without causing a torque shock is determined by searching from a map or table. This operation is the seventh
As shown in Figure (b), the engine torque Tqn after recovery is
This is performed based on the engine torque Tqd during gear shifting, and a set minute range of torque change that does not cause torque shock. Subsequently, in step Sb4, the above return time tq
Calculate the line pressure PL0 at the engine torque return start timing determined from . This calculation is performed using the line pressure PLd at the start of line pressure recovery, the line pressure PLn after recovery, the average recovery speed of the line pressure, and the engine It is calculated from the torque return time tq, and the line pressure is set to a lower value as the line pressure PLd at the start of line pressure return is higher.

Furthermore, FIG. 6 shows engine torque recovery control. In the figure, after starting, step Sc
In step Sc1, it is determined whether the line pressure exceeds the line pressure PLO at the start timing of engine torque recovery, and only if it has exceeded it, in step Sc2, an allowable engine output torque value is determined based on the actual line pressure at this time. After calculating, it is determined in step Sc3 whether or not the engine torque value to be restored exceeds the above-mentioned allowable torque value. If it is greater than the allowable value, the engine returns as it is, but if it is less than the allowable value, the engine torque is increased and returned to a predetermined value that does not cause torque shock in step Sc4, and then returns.

Therefore, in step Sb2 of the control flow shown in FIG. 5, the line pressure adjusting solenoid SOL-6
A return speed detecting means 51 is configured to detect the average return speed within a set time ts during the line pressure rise return due to the stop of the control. Further, in step Sc4 of the control flow in FIG. 6, the higher the line pressure PLd at the start of line pressure return or the faster the average line pressure return speed, the higher the line pressure PLO corresponding to the engine torque return time tq. is set to a low value, and the torque return start timing is set earlier, and the torque return start timing is set later as the engine torque Tqd at the start of line pressure return is larger. are doing.

Therefore, in the above embodiment, during gear shifting, the amount of fuel injected from the fuel injection valves 8, 8 is controlled to decrease to a smaller amount than the normal value, thereby reducing the torque of the engine 1, and at the same time reducing the amount of fuel injected from the fuel injection valves 8, 8. The line pressure of the Z hydraulic control circuit is controlled to be low, reducing the engagement force of the friction element, and smooth gear shifting is performed, so gear shifting shock is effectively reduced.

At the end of the shift, the line pressure begins to be controlled to return to the normal value, and thereafter, when the line pressure increases and reaches the set value PLO, the amount of fuel injected from the fuel injection valves 8 returns to the normal value. It starts to be controlled again.

[0030] At this time, if the line pressure PLd at the start of the return of the line pressure at the end of the shift is high, the engagement force of the friction elements of the automatic transmission Z is also strong, and slippage is unlikely to occur. In this case, since the line pressure PLd at the start of return is high,
Line pressure P at the start timing of torque recovery of engine 1
Since the time required to increase until LO is shortened, the timing of engine torque return becomes relatively early. the result,
Since the torque of the engine 1 is restored quickly, the running performance of the vehicle is improved.

[0031] Furthermore, if the return speed of line pressure is fast,
The tightening force of the friction element is also increased quickly, and as a result, the time it takes to increase until the line pressure PLO when the engine torque starts returning is shortened, so the engine torque returns earlier, and the engine torque can be increased earlier. , and the driving performance of the vehicle improves.

Furthermore, even after the line pressure has reached the line pressure PLO at the above-mentioned torque return start timing, the appropriate engine torque value that does not cause slippage is maintained by the fastening force of the friction element according to the line pressure at that time. When the engine torque to be restored exceeds this appropriate torque value, the restoration of the engine torque is not started and the torque restoration timing is substantially delayed, so the friction element of the automatic transmission Z is unnecessary. It is possible to reliably prevent slipping.

In the above embodiment, the torque reduction means at the time of gear change is configured by controlling the reduction of the fuel injection amount, but other methods include controlling the ignition timing of the air-fuel mixture, controlling the opening degree of the throttle valve 7, or controlling the cylinder of the engine. Of course, it may be configured by numerical control.

[Brief explanation of the drawing]

FIG. 1 is a complaint correspondence diagram.

FIG. 2 is a diagram showing a schematic configuration of an engine.

FIG. 3 is a diagram showing an electric circuit configuration around the automatic transmission.

FIG. 4 is a flowchart showing the overall control during gear shifting.

FIG. 5 is a flowchart showing calculations of engine torque return time and line pressure return speed.

[Fig. 6] Flowchart showing engine torque recovery control
This is a diagram.

FIG. 7 is an explanatory diagram of operation.

[Explanation of symbols]

Claims (3)

[Claims] 1. In an engine in which an input shaft of an automatic transmission is connected to an output shaft, a torque reduction means for reducing output torque of the engine, and a line pressure reduction means for reducing line pressure of a hydraulic control circuit of the automatic transmission. and means for operating the torque reducing means and the line pressure reducing means at the time of shifting of the automatic transmission, the engine control device comprising: means for operating the torque reducing means and the line pressure reducing means at the time of shifting of the automatic transmission; A line pressure return means for stopping operation and restoring line pressure; a line pressure detection means for detecting line pressure; An engine control device comprising: a torque return timing setting means for setting a torque return start timing for stopping the operation of the torque reduction means earlier as the line pressure is higher. 2. A return speed detection means for detecting a return speed of the line pressure by the line pressure return means, wherein the torque return timing setting means determines that the faster the line pressure return speed detected by the return speed detection means, the faster the torque return is. 2. The engine control device according to claim 1, wherein the start timing is set early. 3. The engine according to claim 1, further comprising a torque detection means for detecting engine torque, and wherein the torque return timing setting means sets the torque return start timing later as the engine torque detected by the torque detection means is larger. engine control device.