JPH03260465A - Control device for fluid joint - Google Patents

Abstract

PURPOSE:To solve the problem with poor followup performance by controlling the engagement force of a lockup clutch into slip condition when quick acceleration of a car is sensed, and increasing the drive force transmitted to a torque converter. CONSTITUTION:A torque converter 1 consists of a pump 5 rotating in a single piece with the output shaft 3 of engine, a turbine 6, a stator 7, and a lockup clutch 8. A transmission mechanism 10 is connected with a turbine shaft 9. A control unit 13 is fed with signals about the degree of throttle opening, speed, and engine revolving speed, and sends a control signal to a solenoid 12. When judgement is such that the car is in quick accelerating state, a control signal is given so that the engagement force of the lockup clutch 8 is turned in the slipping state. Thus the rising acceleration of engine revolving is held at a certain specified level to overcome the problem with poor followup response characteristic of the torque converter at the time of quick acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a fluid coupling, and more particularly to a control device for a fluid coupling including a fastening force control means for controlling the fastening force of a lock-up clutch.

(Prior art) Torque converters used in vehicle automatic transmissions include
In order to prevent deterioration of engine fuel efficiency due to so-called slippage of the torque converter, a lock-up clutch that directly connects input and output members is generally used in a predetermined operating range that does not require torque increase action or shift shock absorption action. used.

The torque increasing action of the torque converter is required during acceleration, and for example, Japanese Patent Laid-Open No. 58-37368 discloses that acceleration is detected based on the rate of change over time in the engine load, and when the rate of change is large, That is, a torque converter control method is disclosed in which engagement of a lock-up clutch is released when acceleration is large.

(Problem to be solved by the invention) Torque converters have a problem in that when the vehicle suddenly accelerates, that is, when the accelerator is suddenly depressed, the engine speed suddenly increases.
The energy generated by the engine is consumed by the rapid increase in kinetic energy of the rotating parts of the engine as the engine speed increases, and sufficient driving force is not transmitted to the converter.
For this reason, there is a problem of poor follow-up response during sudden acceleration, in which a time lag occurs between the depression of the accelerator and the increase in driving force, and thus the acceleration.

Therefore, the control method disclosed in Japanese Patent Application Laid-open No. 58-37368, which disengages the lock-up clutch during acceleration, cannot solve the problem of poor follow-up response of the torque converter during sudden acceleration as described above. be.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a control device for a fluid coupling that can overcome the poor follow-up response of a torque converter during sudden acceleration.

(Means for Solving the Problem) In order to solve the above-mentioned problem, the present invention provides a control device for a fluid coupling equipped with a fastening force control means for controlling the fastening force of a lock-up clutch. Provided is a control device for a fluid coupling, characterized in that it is equipped with an acceleration detection means for detecting the acceleration, and a slip means for controlling a lock-up clutch to a slip state for a predetermined period during sudden acceleration.

In a preferred embodiment of the present invention, the slip means is a means for maintaining the increasing acceleration of engine rotation at a predetermined value.

(Function) As described above, in the present invention, when the acceleration detection means detects sudden acceleration of the vehicle, the slip means controls the lock-up clutch to slip for a predetermined period of time. As a result, compared to when the lock-up clutch is disengaged, the rising acceleration of the engine rotation when the accelerator is depressed is reduced, and the driving force transmitted to the torque converter is increased, resulting in poor follow-up response of the torque converter during sudden acceleration. is overcome.

Furthermore, when the acceleration detection means detects sudden acceleration, the slip means controls the lock-up clutch to a slip state for a predetermined period of time to maintain the rising acceleration of engine rotation at a predetermined value. A rise in engine speed can be more reliably prevented, and the poor follow-up response of the torque converter during sudden acceleration can be more reliably overcome.

(Example) The present invention will be described in detail below based on the accompanying drawings.

In FIG. 1, 1 is a torque converter provided with a control device according to an embodiment of the present invention. The torque converter 1 is fixedly installed on one side of a case 4 connected to an output shaft 3 of an engine 2, and includes a pump 5 that rotates integrally with the engine output shaft 3, and the other side of the case 4 facing the pump 5. A turbine 6 is disposed rotatably with respect to the case 4 on the side of the case 4 and is rotationally driven via hydraulic oil by the rotation of the pump 5, and a turbine 6 is interposed between the pump 5 and the turbine 6. The engine includes a stator 7 that increases torque when the ratio of the turbine rotation speed to the pump rotation speed is below a predetermined value, and a lock-up clutch 8 interposed between the turbine 6 and the case 4. The rotation of the turbine 6 is outputted by the turbine shaft 9 and inputted to the gear transmission mechanism IO, and the lock-up clutch 8 is connected to the turbine shaft 9.
When the engine is fastened to the case 4, the engine output shaft 3 and the turbine shaft 9 are directly connected through the case 4.

Hydraulic oil supplied from a pump (not shown) is introduced into the lock-up clutch 8 through an oil path 11, and the oil pressure of the hydraulic oil is controlled by a solenoid 12 installed in the middle of the oil path 11. Lockup clutch 8
The fastening state between the case 4 and the case 4 is controlled.

A control unit 1 basically consisting of a CPU, ROM, and RAM for controlling the engagement state of the lock-up clutch.
3, and the control unit 13 receives an engine rotation signal and a throttle opening signal from an engine rotation sensor 14 and a throttle sensor I5, respectively, and a vehicle speed signal from a vehicle speed sensor (not shown). Further, the control unit 13 outputs a control signal for controlling the operation of the solenoid 12.

A map of the control area shown in FIG. 2 is stored in the ROM of the control unit 13 of the present control device.

In this map, as a function of the throttle opening degree, that is, the engine load and vehicle speed, there is a lock-up region (2) in which the lock-up clutch is fully engaged in high-speed driving ranges, and a lock-up clutch is disengaged in low-speed driving ranges. Converter areas (3) are defined as shown in the figure.

The operation of the control device according to this embodiment configured as described above will be explained below based on the flowchart shown in FIG. Note that in the following description, S indicates a control step.

Control starts when the engine starts.

The control unit 13 first reads the throttle opening signal θ (SL), then calculates the time differential of the throttle opening θ, that is, the throttle opening speed (S2), and determines whether the throttle opening speed is equal to or higher than a predetermined value α. Determine (S3)
.

If the throttle opening speed is less than the predetermined value α, the control unit h13 determines that the vehicle is not in a rapid acceleration state, and controls the lock-up clutch 8 of the torque converter 1 based on the control area diagram in FIG.

That is, the throttle opening signal θ and the vehicle speed signal V are read (S4), and if the operating range is in the range (3) in FIG. 2, a control signal is sent to the solenoid 12 to fully engage the lock-up clutch (S5). , S6), if not at L, the lock-up clutch is disengaged and the torque converter 1 is placed in the converter state (85.87).

With the above control, during normal driving except during sudden acceleration,
Torque is increased in low speed ranges where acceleration performance is required, and fuel efficiency is improved in high speed ranges where acceleration performance is less required.

When the throttle opening speed is equal to or greater than the predetermined value α, the control unit 13 determines that the vehicle is in a rapid acceleration state, and performs the following control.

First, the control unit 13 reads the engine rotation signal N (S8), calculates the time differential of the engine rotation speed N, that is, the engine rotation acceleration (S9), and determines whether the engine rotation acceleration is equal to or greater than a predetermined value β. (S10).

When the engine rotational acceleration is equal to or higher than the predetermined value β, the control unit 13 sets a built-in timer to a predetermined period T (S11), and then sends a control signal to the solenoid 12 to increase the engagement force of the lock-up clutch 8 ( S l 2)
, On the other hand, if the engine rotational acceleration is less than the predetermined value β, the engagement force of the lock-up clutch 8 is reduced (S13).
. That is, the lock-up clutch 8 is put into a slip state, and its engagement force is controlled. The control unit) 13 is
The slip control of the lock-up clutch 8 performed in steps 8 to 13 is repeated for a predetermined period T (S14.515). With the above control, during sudden acceleration, the engine rotational acceleration is maintained near the predetermined value β for the predetermined period T, so that the engine rotation and, by extension, the kinetic energy of the rotating members of the engine do not sharply increase when the accelerator is depressed. Therefore, the engine torque is transmitted to the torque converter 1 without being consumed by increasing the kinetic energy of the engine rotating members, and the poor follow-up response of the torque converter 1 at the initial stage of acceleration is improved.

Although the present invention has been described in detail above, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and that various modifications can be made within the scope of the invention described in the claims. For example, in the above embodiment, the lock-up clutch 8 is slip-controlled so that the engine rotational acceleration becomes a predetermined value, but the turbine shaft 9 of the torque converter 1
A turbine rotation sensor is provided to input a turbine rotation signal to the control unit 13, and based on the turbine rotation signal and the engine rotation signal, a lock is provided so that the difference between the turbine rotation speed and the engine rotation speed is maintained at a predetermined value. The up clutch 8 may be subjected to slip control (effect) As can be seen from the above explanation, in the control device according to the present invention, when the acceleration detection means detects sudden acceleration of the vehicle, the slip means is controlled for a predetermined period of time. Controls the lock-up clutch into a slip state. As a result, compared to when the lock-up clutch is disengaged, the rising acceleration of the engine rotation when the accelerator is depressed is reduced, and the driving force transmitted to the converter is increased, which reduces the poor follow-up response of the torque converter during sudden acceleration. be overcome.

Furthermore, when the acceleration detection means detects sudden acceleration, the slip means controls the lock-up clutch to a slip state for a predetermined period of time to maintain the rising acceleration of engine rotation at a predetermined value. An increase in engine speed can be more reliably prevented, and poor follow-up response of the torque converter during sudden acceleration can be more reliably overcome.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a torque converter provided with a fluid coupling control device according to an embodiment of the present invention. FIG. 2 is a map showing the control area of the control device of FIG. 1. FIG. 3 is a flow chart of the operation of the control device of FIG. I... Torque converter, 6... Turbine, 8... Lock-up clutch, 12... Solenoid, 13... Control unit. 15...Throttle sensor.

Claims (2)

[Claims] (1) In a fluid coupling control device equipped with a fastening force control means for controlling the fastening force of a lockup clutch, the acceleration detecting means detects a sudden acceleration state of the vehicle, and the lockup clutch is kept in a slip state for a predetermined period during sudden acceleration. 1. A control device for a fluid coupling, comprising: a slip means for controlling. (2) The control device according to claim 1, wherein the slip means is a means for maintaining an increasing acceleration of engine rotation at a predetermined value.