JPH1018877A - Control device for engine with automatic transmission - Google Patents

Abstract

(57) [Problem] To appropriately reduce a shift shock in a downshift with a throttle valve fully closed. When an idle switch is turned on (S1),
The deceleration shift control for maintaining the rotation speed at which the deceleration fuel cut is performed is executed (S3). On the other hand, when the downshift is performed during the deceleration fuel cut (S4), the torque is forcibly increased by increasing the auxiliary air amount (S6, S8) and interrupting the fuel cut (S9). Shift shocks are thereby reduced. Here, when the downshift during the deceleration fuel cut is due to the driver's shift operation (manual downshift),
The amount of increase in the amount of auxiliary air is made smaller than at the time of a downshift (auto downshift) by the deceleration shift control (I
SCmn <ISCauto), so that an appropriate deceleration feeling corresponding to the driver's intention to decelerate can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an engine with an automatic transmission, and more particularly, to alleviate a shift shock by forcibly increasing the engine torque during a downshift with a throttle valve fully closed. About technology.

[0002]

2. Description of the Related Art Conventionally, there has been known an electronically controlled fuel injection device which performs a so-called deceleration fuel cut in which fuel supply to an engine is stopped in a deceleration operation state in which an engine rotation speed is equal to or higher than a predetermined value. On the other hand, in an automatic transmission connected to an engine in which the deceleration fuel cut is performed, a function of automatically controlling a shift speed during a deceleration operation so as to maintain an engine rotation speed in which the deceleration fuel cut is performed (hereinafter, a function for deceleration) A shift control device having a shift control has been proposed (see Japanese Patent Application Laid-Open No. Hei 4-203559).

Japanese Patent Laid-Open Publication No. Hei 7-247874 discloses a shift in which the engine brake is activated by a manual operation (for example, an operation of selecting a range having a characteristic of selecting a low speed stage such as an S range or an L range) in a fuel cut state. A technique has been disclosed in which when a downshift to a gear is performed, the intake air amount is increased and the fuel cut is interrupted to increase the engine torque, thereby mitigating the shift shock accompanying the downshift. I have.

[0004]

The control disclosed in Japanese Patent Application Laid-Open No. 7-247874 is intended to alleviate a shift shock at the time of a downshift caused by a manual operation by a driver. By executing the deceleration shift control disclosed in Japanese Patent Application Laid-Open No. 4-203559, a downshift in which the engine brake is effective is also performed.

Therefore, when a downshift is performed by the deceleration shift control (hereinafter, referred to as an auto downshift), it is desired that the shift shock be reduced by increasing the torque as in the manual downshift. However, at the time of a manual downshift, it is desirable to leave a shift shock enough to provide a sense of deceleration rather than completely eliminating a shift shock because the driver intends to decelerate. Since the shift is performed irrespective of the user's operation, it is desirable that the shift shock be as small as possible.

[0006] However, Japanese Patent Application Laid-Open No.
In the case where the shift shock mitigation control disclosed in Japanese Patent Application Laid-Open No. 4-4203 is applied to the speed reduction control disclosed in Japanese Patent Application Laid-Open No. Hei 4-203559, a manual downshift and an automatic downshift can be performed. If the torque up amount is set to match the demand for manual downshift, the shift shock will be too large during the auto downshift, and conversely, the auto downshift If the torque increase amount is set in accordance with the demand of the time, there is a problem that an appropriate deceleration feeling cannot be obtained at the time of a manual downshift.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an appropriate deceleration feeling during a manual downshift while satisfactorily mitigating a shift shock during an automatic downshift. And

[0008]

Therefore, according to the first aspect of the present invention, an automatic transmission configured to reduce a shift shock by increasing the engine torque at the time of a downshift with the throttle valve fully closed. In the control device for the engine, the amount of increase in the torque is changed between a downshift in accordance with a manual shift operation and an automatic downshift in accordance with a preset shift schedule.

On the other hand, the invention according to claim 2 is configured as shown in FIG. In FIG. 1, the shift shock mitigation means forcibly increases the engine torque to reduce the shift shock during a downshift with the throttle valve fully closed. The manual downshift means causes a downshift to be performed according to a manual shift operation, and the automatic downshift means causes an automatic downshift to be performed according to a preset shift schedule.

Here, the torque increase changing means changes the amount of increase in torque in the shift shock reducing means between the time of downshifting by the manual downshifting means and the time of downshifting by the automatic downshifting means. That is, according to the first and second aspects of the present invention, a downshift according to a manual shift operation (at a manual downshift) and an automatic downshift according to a preset shift schedule (auto downshift) ), The required amount of torque increase, in other words, the shift shock demand is different. Therefore, even when downshifting with the same throttle valve fully closed, there is a difference between manual downshift and auto downshift. A different amount is provided as the amount of torque increase for alleviating the shift shock depending on which of the above.

According to the third aspect of the present invention, the torque increase changing means is configured to increase the amount of increase in torque at the time of downshifting by the automatic downshifting means, as compared with the time of downshifting by the manual downshifting means. . At the time of a manual downshift, it is desirable to generate a shift shock enough to provide a sense of deceleration because the driver intends to decelerate, but at the time of an automatic downshift, the shift is performed irrespective of the driver's operation. Therefore, it is desirable that the shift shock be as small as possible. Therefore, by making the torque increase during the manual downshift relatively small so that an appropriate deceleration feeling can be obtained, the torque increase during the auto downshift is made relatively large and the shift shock can be reliably prevented. Be relieved.

According to the invention described in claim 4, the shift shock mitigation means forcibly increases the intake air amount of the engine to forcibly increase the engine torque. That is, at the time of a downshift in a fully closed state of the throttle valve, the torque is increased by temporarily increasing the intake air amount to reduce the shift shock.

According to a fifth aspect of the present invention, the shift shock reducing means forcibly increases the engine torque by forcibly increasing the amount of air supplied to the engine by the electronically controlled throttle valve. did. In an engine having an actuator for opening and closing the throttle valve and having an electronically controlled throttle valve configured to electronically control the opening of the throttle valve, the intake air is increased by forcibly increasing the opening of the electronically controlled throttle valve. By increasing the amount, the torque is increased to reduce the shift shock.

According to a sixth aspect of the present invention, the shift shock reducing means forcibly increases the engine torque by forcibly increasing the amount of air supplied to the engine bypassing the throttle valve. And A general configuration is to provide an auxiliary air passage that bypasses the throttle valve and control the opening of an idle control valve interposed in the auxiliary air passage to adjust the intake air amount during idling operation. By forcibly increasing the opening degree of the idle control valve, the amount of intake air is increased, thereby increasing the torque for alleviating the shift shock.

According to a seventh aspect of the present invention, there is provided a fuel supply stopping means for stopping the fuel supply in a deceleration operation state at a predetermined engine rotation speed or more, wherein the auto downshift means is configured to reduce the engine rotation speed in the deceleration operation state. The automatic downshift is performed according to a preset downshift schedule so as to be equal to or higher than a predetermined engine rotation speed at which the fuel supply is stopped, and the shift shock reducing means is provided by the fuel supply stopping means. The fuel supply is stopped to increase the engine torque.

When a means for performing a fuel cut during deceleration operation is provided, downshifting is performed to maintain the rotational speed at which the fuel cut is performed, so that the period during which the fuel cut is performed is made as long as possible, and fuel consumption performance is improved. At the time of a downshift during the fuel cut, the fuel supply is temporarily restarted to increase the torque, thereby alleviating a shift shock accompanying the downshift. Here, at the time of an automatic downshift for extending the fuel cut period and at the time of a downshift in response to a manual shift operation during the fuel cut, fuel supply is temporarily resumed to alleviate a shift shock. However, by appropriately reducing the amount of torque increase during a manual downshift, an appropriate feeling of deceleration can be obtained.

[0017]

Embodiments of the present invention will be described below. In FIG. 2 showing a system configuration of the embodiment, an automatic transmission 2 is connected to an engine 1. A control unit 10 is provided to solenoid valves 2A to 2E for controlling hydraulic pressures to various transmission elements of the automatic transmission 2.
Outputs a control signal, whereby the speed change operation is controlled.

On the other hand, a throttle valve 12 which opens and closes in conjunction with an accelerator pedal (not shown) is provided in an intake passage 11 of the engine 1. Also, the throttle valve
An idle speed control valve (hereinafter, referred to as an ISC valve) 14 for adjusting the amount of auxiliary air supplied to the engine via the auxiliary air passage 13 is provided in the auxiliary air passage 13 provided by bypassing the auxiliary air passage 13. ing.

On the other hand, the control unit 10 includes:
Detection signals from various sensors are input. The various sensors include a throttle sensor 3 including an idle switch 3A that is turned on when the throttle valve 12 is fully closed, and an air flow that detects an intake air flow rate Q of the engine 1 while detecting the opening degree θ of the throttle valve 12. A meter 4 is provided. Further, a rotation sensor (crank angle sensor) 5 for detecting the engine rotation speed N is provided in a distributor or the like. Further, a vehicle speed sensor 6 for detecting a vehicle speed VSP and a gear position sensor 7 for detecting a speed (gear position) of the automatic transmission 2 are provided. In addition, there are provided a brake switch 8 which is turned on when the foot brake is operated, and an inhibitor switch 9 which detects a range selected by an A / T select lever operated by the driver.

The A / T select lever allows any one of the ranges P, R, N, D, 3, 2, and 1, for example, to be arbitrarily selected. The shift is controlled according to the range selected by the A / T select lever. Here, for example, an operation such as D → 3, 3 → 2 may cause a downshift request.
The downshift according to the operation of the T select lever corresponds to a manual downshift means.

In the case of an automatic transmission having a manual mode, the function of performing a downshift in response to a downshift instruction in the manual mode corresponds to a manual downshift means. Also, S
In the case where a low speed range such as a range or an L range is provided, a function of performing a downshift by a selection operation from the normal traveling range to the S range or the L range corresponds to a manual downshift means. Will be.

The control unit 10 controls the fuel supply amount to the engine 1 based on the detection results of the intake air flow rate Q and the engine rotation speed N, while the throttle valve is fully closed (idle switch 3A is ON) and The fuel supply is stopped in the deceleration operation state where the engine speed N (rpm) is equal to or higher than the set speed N _C , and the fuel supply is restarted when the engine speed becomes equal to or lower than the set speed N _R. It corresponds to a supply stopping means).

The control unit 10 usually has a vehicle speed VSP and a throttle valve opening θ (accelerator opening).
The shift control is performed according to a preset shift schedule based on the above, but at the time of deceleration operation, the engine speed is maintained at or above the set rotation speed N _C in the deceleration fuel cut control instead of the normal shift control. The deceleration shift control for controlling the shift in a shift schedule that promotes the execution of the deceleration fuel cut is executed (this function corresponds to an auto downshift means).

On the other hand, the control unit 10 forcibly increases the torque of the engine during a downshift (shift to a gear position where the engine brake is effective) with the throttle valve 12 fully closed, thereby mitigating a shift shock. A function as a shift shock mitigation means is provided, and such a function will be described with reference to the flowchart of FIG. In the flowchart of FIG. 3, first, step 1 (S1 in the figure)
It is written. In the following, the idle switch 3A
Is turned on or not.

If the idle switch 3A is not ON and the throttle valve 12 is open, the routine proceeds to step 2, where, for example, a regular service based on a shift schedule preset according to the opening θ of the throttle valve 12 and the vehicle speed VSP. Is executed. On the other hand, idle switch 3
During the deceleration operation in which A is ON (the throttle valve 12 is in the fully closed state), the routine proceeds to step 3, where the speed reduction control is executed. The details of the deceleration shift control will be described later.

In the next step 4, it is determined whether or not a fuel cut is being performed. In step 5, it is determined whether or not a downshift request (a shift request to a gear position where engine braking is effective) is generated by the driver's A / T select lever operation (for example, an operation to switch from the D range to the three range). .
Hereinafter, the downshift according to the operation of the A / T select lever is referred to as a manual downshift.

If it is a manual downshift, the routine proceeds to step 6, where the target value of the auxiliary air amount (ISC air amount) adjusted by the ISC valve 14 is manually set in advance with respect to a basic value ISCbase corresponding to the engine request. The intake air amount of the engine is increased by the increase allowance ISCmn by increasing the increase allowance ISCmn set as a value for the downshift.
Only to force an increase.

In step 9, the fuel cut is interrupted, and the state in which fuel supply is resumed is maintained until the end of the downshift is determined in step 10, with the increase in the air amount at this time. The combustion of the engine forcibly increases the torque of the engine, thereby alleviating the occurrence of a shift shock accompanying a manual downshift. When the end of the downshift is determined in step 10, the process proceeds to step 11,
After returning to the normal fuel cut state, in step 12, the target value of the auxiliary air amount is returned to the basic value ISCbase.

On the other hand, if it is determined in step 5 that it is not a manual downshift, the process proceeds to step 7 to determine whether or not an automatic downshift by the deceleration shift control (hereinafter referred to as an auto downshift). Determine. If it is determined in step 7 that it is not an automatic downshift, that is, if it is neither a manual downshift nor an auto downshift, there is no need for torque-up control to reduce shift shock. This routine ends as it is.

On the other hand, even during an automatic downshift, a shift for maintaining engine cut is performed by a shift for maintaining the fuel cut rotation. Therefore, it is necessary to reduce a shift shock accompanying the downshift. Therefore, when the automatic downshift is in progress, the routine proceeds to step 8, in which the target value of the auxiliary air amount (ISC air amount) adjusted by the ISC valve 14 is automatically reduced in advance with respect to the basic value ISCbase according to the engine request. The intake air amount of the engine is forcibly increased by the increase allowance ISCauto by increasing the increase allowance ISCauto set as the value for the shift. It should be noted that the setting is made such that ISCauto> ISCmn, so that the air amount is increased more greatly during the automatic downshift than during the manual downshift. Is equivalent to

When the target value of the auxiliary air amount is increased and corrected in step 8, the process proceeds to step 9, in which the fuel cut is interrupted, and the engine torque is increased by restarting the combustion with the air amount increased in advance. Shift shifting is alleviated by downshifting, and the end of downshifting is a step
If it is determined in step 10, the process proceeds to step 11 to return to the fuel cut state, and in step 12, the target value of the auxiliary air amount is returned to the basic value ISCbase.

As described above, when a downshift (shift to a gear position where engine braking is effective) is performed during fuel cut with the throttle valve fully closed, the intake air amount of the engine is reduced by the auxiliary air amount. The fuel supply is temporarily restarted after being increased by the forced increase correction, whereby the engine torque is increased, and the increase in the torque reduces the shift shock accompanying the downshift.

However, the amount of increase in the amount of auxiliary air, that is, the amount of increase in engine torque, is set to be greater during an automatic downshift than during a manual downshift (ISCauto> ISCmn). As a result, it is possible to sufficiently reduce the shift shock during the automatic downshift, and to provide an appropriate deceleration feeling appropriate for the driver's downshift operation (intention to decelerate) during the manual downshift.

In the above description, the opening of the ISC valve is forcibly increased to increase the intake air amount of the engine, thereby increasing the torque. However, the throttle valve is opened and closed. With an actuator,
In an engine having an electronically controlled throttle valve configured to electronically control the opening of the throttle valve, an increase in the amount of air, that is, a shift shock, is caused by forcibly increasing and correcting the target opening of the electronically controlled throttle valve. It is possible to increase the torque for alleviation, and an embodiment of such a configuration is shown in the flowchart of FIG.

In the flowchart of FIG.
Steps other than steps 16, 18, and 22 perform exactly the same processing as in the flowchart of FIG. 3, and steps 16, 18, and 22 correspond to steps 6, 8, and 12 of the flowchart of FIG. The only difference is that the portion is changed from the target value of the auxiliary air amount to the target opening TVO of the electronically controlled throttle valve.

That is, in step 16, the basic target opening degree TVObase of the electronically controlled throttle valve is increased by an increasing amount TVOMn which is set in advance as a value for manual downshifting. Degree T
VObase is increased by an increment TVOauto which is set in advance as a value for the automatic downshift, and in step 22, a process of returning the target opening to the basic value TVObase is executed.

The deceleration shift control performed in step 3 (step 13 in FIG. 4) will now be described with reference to the flowchart of FIG. First, in step 51, the engine rotational speed N ₄ in the case of control from the current operating state gear position G to the fourth speed, is calculated by the following equation. However, if the current state is the fourth speed, it is sufficient to set N ₄ = N (the same applies to steps 54 and 57 described later).

N ₄ = VSP · K 1 · I ₄ · E where K 1 is a constant for converting the vehicle speed VSP (km / h) into the rotation speed (rpm) of the output shaft of the transmission, and I ₄ is 4 Gear ratios (also I ₃ , I ₂ , I ₁ are 3rd, 2nd, 1st respectively
And E is the speed ratio of the torque converter (assuming constant).

Then, the program proceeds to a step 52, wherein a fourth speed prediction engine is executed.
Gin rotation speed N_FourIn the deceleration fuel cut control
Set rotation speed N_CCompare with And N_Four≧ N_CIn
If it is determined that the
The gear position G when performing the speed control is determined to be the fourth speed, and_X=
I_FourAnd set. On the other hand, at step 52, N_Four<N_CAnd judgment
When it is determined, the process proceeds to step 54, where the same arithmetic expression
 (I_FourTo I_Three3 speed prediction engine
Rotation speed N _Three, And then proceeds to step 55 where N_ThreeTo
N_CCompare with

When it is determined that N ₃ ≧ N _C , the process proceeds to step 56 in the same manner as described above, and the gear position G for performing the speed reduction control is determined to be the third speed, and I _X = I C
₃ is set, and when it is determined that N ₃ <N _C , the process proceeds to step 57. Hereinafter, as compared to the set rotation speed N _C deceleration fuel cut control while seeking a predicted engine speed N _2, N ₁ in the same manner as in Step 57 to Step 62, N ₂ ≧ N _C,
I _X = I ₂ when it is determined that N ₁ ≧ N _C, I _X
= I to ₁ and the set.

When it is determined that N ₁ <N _C , it is impossible to increase the rotation speed N _C or more by the speed change control. Therefore, the speed reduction control is ended while the gear position is kept as it is. . As described above, sequentially predicts the engine speed during the shift from the high-speed side of the gear position, when determined as a gear position of the speed reduction gear change control the fastest side gear position among the gear position at which the above N _C, Proceed to step 63.

In step 63, the deceleration when the gear is shifted to the determined gear position is calculated. This vehicle speed VSP _X after shifting _{(VSP X = K2 · I X} · N X: K2 is a constant)
Is calculated as the deviation ΔVSP from the current vehicle speed VSP. In step 64, the deviation ΔVSP is compared with a predetermined value. If the difference ΔVSP is larger than the predetermined value, it is determined that the deceleration due to the engine brake becomes too large when the shift is performed, the shift is stopped, and the current gear position is maintained. Let it.

On the other hand, when it is determined in step 64 that the difference ΔVSP is equal to or smaller than the predetermined value, the routine proceeds to step 65, in which the speed is controlled to the determined gear position _IX . By such deceleration shift control, a gear position is selected such that the engine rotation speed N becomes equal to or higher than the set rotation speed N _C during the deceleration operation. Therefore, the opportunity for performing the deceleration fuel cut is expanded, and the fuel efficiency is improved. Etc. can be achieved.

In the deceleration shift control described above, the engine speed N is controlled so as to be equal to or higher than a set rotation speed N _C which is a fuel cut start condition. However, after the deceleration fuel cut is started. May be configured such that the shift speed is selected so as to be equal to or higher than the set rotation speed N _R at which fuel supply is restarted.

[0045]

As described above, according to the first and second aspects of the present invention, at the time of a downshift with the throttle valve fully closed, the downshift corresponds to a manual shift operation (manual downshift). shift)
Or an automatic shift (auto downshift) according to a preset shift schedule, the amount of torque increase for alleviating the shift shock is varied. Correspondingly, there is an effect that the shift shock mitigation control can be appropriately executed.

According to the third aspect of the invention, at the time of an automatic downshift, the shift shock is sufficiently reduced while
At the time of a manual downshift, there is an effect that an appropriate deceleration feeling can be given according to the driver's intention to decelerate. According to the fourth aspect of the present invention, by forcibly increasing the intake air amount of the engine, the torque of the engine can be increased and the shift shock accompanying the downshift can be reduced.

According to the fifth aspect of the present invention, there is an effect that the torque can be increased by using the electronically controlled throttle valve to reduce the shift shock caused by the downshift. According to the sixth aspect of the present invention, there is an effect that the mechanism for adjusting the amount of air at the time of idling can be used to increase the torque to reduce the shift shock caused by the downshift.

According to the seventh aspect of the invention, there is an effect that the speed change shock during downshift during the fuel cut can be appropriately mitigated while promoting the deceleration fuel cut.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the invention described in claim 2;

FIG. 2 is a system configuration diagram of the automatic transmission according to the embodiment.

FIG. 3 is a flowchart showing a state of a shift shock mitigation control by an ISC valve.

FIG. 4 is a flowchart showing a state of a shift shock mitigation control by an electronically controlled throttle.

FIG. 5 is a flowchart showing a state of deceleration shift control.

[Explanation of symbols]

 Reference Signs List 1 engine 2 automatic transmission 3A idle switch 3 throttle sensor 4 air flow meter 5 rotation sensor 6 vehicle speed sensor 7 gear position sensor 9 inhibitor switch 10 control unit 11 intake passage 12 throttle valve 13 auxiliary air passage 14 ISC valve

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // F16H 59/08 F16H 59/08

Claims (7)

[Claims] 1. A control device for an engine with an automatic transmission, configured to increase a torque of an engine during a downshift with a throttle valve fully closed to reduce a shift shock. A control device for an engine with an automatic transmission, wherein the amount of increase in the torque is changed between a shift and an automatic downshift according to a preset shift schedule. 2. A shift shock mitigation means for forcibly increasing engine torque to reduce a shift shock when a downshift is performed with the throttle valve fully closed, and a manual shiftdown operation performed in response to a manual shift operation. Downshift means, automatic downshift means for performing an automatic downshift in accordance with a preset shift schedule, at the time of downshift by the manual downshift means, and at the time of downshift by the automatic downshift means. A control device for an engine with an automatic transmission, characterized by comprising: a torque increase changing means for changing an amount of increase in torque in the shift shock reducing means. 3. The apparatus according to claim 2, wherein said torque increase changing means increases the amount of increase in torque at the time of downshifting by said automatic downshifting means, as compared with at the time of downshifting by said manual downshifting means.
A control device for an engine with an automatic transmission according to the above. 4. The automatic transmission according to claim 2, wherein the shift shock mitigation means forcibly increases the engine torque by forcibly increasing the intake air amount of the engine. Engine engine control device. 5. The shift shock reducing means forcibly increases the engine torque by forcibly increasing the amount of air supplied to the engine by an electronically controlled throttle valve. A control device for an engine with an automatic transmission according to the above. 6. The engine according to claim 1, wherein the shift shock mitigation means forcibly increases the amount of air supplied to the engine by bypassing the throttle valve, thereby forcibly increasing the torque of the engine. A control device for an engine with an automatic transmission according to claim 4. 7. A fuel supply stopping means for stopping fuel supply in a deceleration operation state higher than a predetermined engine rotation speed, wherein the auto downshift means stops the fuel supply in an engine rotation speed in a deceleration operation state. Automatic downshift is performed according to a preset downshift schedule so as to be equal to or higher than a predetermined engine rotation speed, and the shift shock mitigation means interrupts the stop of fuel supply by the fuel supply stop means. The control device for an engine with an automatic transmission according to any one of claims 2 to 6, wherein the engine torque is increased.