JPH076561B2 - Clutch control device for vehicles equipped with automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch control device for a vehicle equipped with an automatic transmission, which controls the amount of engagement of a wet clutch that lubricates a clutch friction surface with circulating lubricating oil by means of the lubricating oil temperature.

<Prior Art> In recent years, a vehicle equipped with an automatic transmission has been widely used in order to facilitate a driving operation of the vehicle. An automatic clutch is used in such a vehicle, and a dry type single plate is mainly used as hardware, but recently in a large-sized vehicle, as a hardware for clutch friction surface and other lubrication and cooling, There have been many examples of using a wet clutch of the type in which lubricating oil is circulated in a clutch device.

<Problems to be Solved by the Invention> However, in this type of wet Kutch device, the lubricating oil is circulated to lubricate the clutch friction surface and other clutch mechanisms and to cool the clutch friction surface and the like. However, the friction coefficient of the clutch changes remarkably as shown in FIG. 4 because the viscosity changes when the lubricating oil temperature changes. That is, when the temperature of the lubricating oil becomes high and the viscosity thereof extremely decreases, an oil film is cut off on the friction surface of the clutch when the clutch is engaged (during so-called time slip), which causes undesirable phenomena such as seizure and deterioration of the friction surface of the clutch. It happens.

Further, the clutch facing is swollen due to the oil immersion of the lubricating oil, but the thickness of the facing changes depending on the oil temperature. Furthermore, in the facing, when the amount of work applied to the clutch increases, frictional heat is generated and the circulating oil temperature rises,
The practical upper limit temperature of facing may be exceeded.

As described above, in a vehicle equipped with an automatic transmission using a wet clutch, the connection / disconnection characteristics during clutch connection / disconnection change significantly due to changes in the oil temperature of the lubricating oil that circulates so as to lubricate and cool the wet clutch. There was a problem that it would end up. Further, if the half-clutch state (clutch slip state) is frequently used on a congested road, a sloping road, etc., the facing temperature rises excessively, and in the worst case, seizure of the clutch may cause the vehicle to be unable to run.

In view of the above problems, the present invention maintains the clutch engagement / disengagement characteristics in a good state by correcting the clutch engagement amount (specifically, for example, by correcting the stroke of the clutch actuator, corresponding to the lubricating temperature, Seizure of clutch friction surface,
An object of the present invention is to provide a clutch control device for a vehicle equipped with an automatic transmission that attempts to prevent deterioration and the like.

<Means for Solving the Problems> In order to achieve the above object, the present invention uses a wet clutch that lubricates a clutch friction surface with a circulating lubricating oil, and a control device connects and disconnects the clutch via a clutch actuator. In the clutch control device for a vehicle equipped with the automatic transmission described above, an oil temperature sensor for detecting the temperature of the lubricating oil is provided, and the control device includes means for obtaining a normal clutch engagement amount, and a signal from the oil temperature sensor. A means for obtaining a correction amount of the clutch engagement amount set in advance based on the above, a means for calculating the clutch engagement amount corrected from the correction amount and the normal clutch engagement amount are provided, and the clutch is further connected. In this case, means for controlling the clutch actuator so that the clutch has the corrected clutch engagement amount is provided. .

<Operation> In an automatic transmission control device having a clutch, the clutch engagement amount is usually determined according to the engine speed, the transmission input shaft speed, the engine load, and the like. In the present invention, first, the normal clutch engagement amount fl is obtained from a memory or the like, then the lubricating oil temperature is detected by the oil temperature sensor, and the clutch engagement amount to be hydraulicized corresponding to the lubricating oil temperature. Extract f (T) from memory. The desired clutch engagement amount F with respect to the detected lubricating oil temperature is obtained by subtracting the correction amount f2 from the normal clutch engagement amount fl which has not been corrected at all, so in the next step the clutch engagement amount f1 is calculated. The engagement correction amount f2 is subtracted from this to obtain the clutch engagement target amount F. Next, the clutch actuator is energized so that the clutch disc of the clutch reaches the clutch engagement target amount F.

Accordingly, even if the oil temperature changes, the clutch engagement amount is corrected by the function f (T) of the oil temperature and the clutch actuator is operated so as to obtain the desired clutch engagement amount F. Even if it changes, the friction coefficient of the clutch friction surface is kept almost constant.

<Examples> Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of a wet clutch and its control device.
In FIG. 1, 1 is an oil tank for storing lubricating oil that circulates through a clutch, 2 is a pump that sucks up and supplies lubricating oil from the oil tank 1, 3 is a nozzle that injects lubricating oil from the pump 2, and 4 is Main drive shaft, which is the drive shaft of the vehicle, 5 is a sleeve retainer, 6 is a hula wheel, 7
Is a housing for accommodating the clutch, 8 is a pressure plate pressed by the flywheel 6, 9 is a clutch disc, 10 is an oil cooler for cooling the lubricating oil injected from the nozzle 3, 11 is a strainer, and 12 is a lubricating oil. An oil temperature sensor for detecting the temperature, 13 is a clutch actuator for controlling the amount of engagement between the clutch disc 9 and the flywheel 6,
Reference numeral 14 is an electronic control device that controls the operation of the clutch actuator 13, and reference numeral 15 is a clutch stroke sensor.

In such a wet clutch, the lubricating oil in the oil tank 1 is sucked up by the pump 2 and cooled by the oil cooler 10, and the cooled lubricating oil is injected from the nozzle 3 to each part of the Kutch including the clutch friction surface. Further, an oil temperature sensor 12 for lubricating oil is provided in the clutch housing 7 to detect the oil temperature, and the electronic control unit 14 is configured to control the clutch engagement amount based on the detected oil temperature.

The operation of the electronic control unit 14 for adjusting the clutch engagement amount based on the oil temperature will be described below with reference to the flowchart of FIG.

The electronic control unit 14 is composed of a microprocessor, which has a read-only memory (RO
It is controlled according to the program stored in M). The flowchart of FIG. 2 shows the flow of processing of the microprocessor according to the control program stored in this ROM.

In FIG. 2, in step ST1, a normal clutch engagement amount f1 which is not corrected at all is obtained. Next, at step ST2, the lubricating oil temperature T is detected by the oil temperature sensor 12. The clutch engagement amount f (T) to be corrected with respect to the oil temperature T is stored in advance in the memory in a relationship as shown in FIG.
In step ST3, the clutch engagement amount f (T) to be corrected is obtained from the oil temperature detected in step ST2 by referring to the memory, and this is set as the clutch engagement amount correction amount f2. Now
The desired clutch engagement amount F with respect to the lubricating oil temperature T is calculated from the normal clutch engagement amount f1 which is not corrected at all in steps.
It is a value obtained by subtracting the correction amount f2 obtained in ST3. Therefore, in step ST4, the clutch engagement target amount F is obtained by subtracting the engagement correction amount f2 from the clutch engagement amount f1. Next, at step S5, the clutch actuator 13 is urged so that the clutch disc 9 reaches the clutch engagement target amount F. As a result, even if the oil temperature T changes, the clutch engagement amount is corrected by the function f (T) of the oil temperature T so that the desired clutch engagement amount F can be obtained.
Since 13 is operated, even if the oil temperature T changes, the friction coefficient of the clutch friction surface is always kept substantially constant, and there is no difference in the dynamic friction torque of the clutch.

<Effects of the Invention> As described above, the clutch control device of the vehicle equipped with the automatic transmission of the present invention uses a wet clutch that lubricates the friction surface of the clutch with the circulating lubricating oil, and the clutch is operated by the control device via the clutch actuator. In a clutch control device for a vehicle equipped with an automatic transmission that connects and disconnects, the control device detects an uncorrected normal clutch engagement amount and a lubricating oil temperature when connecting the clutch. The clutch engagement amount corrected for the lubricating oil temperature is calculated by calculating the difference between the lubricant oil temperature and the set correction amount obtained based on the signal from the sensor, and the wet clutch is corrected for the clutch engagement amount. Since the clutch actuator is controlled so as to obtain the above, even if the lubricating oil temperature of the clutch changes, the clutch engagement By adjusting the total amount, the friction coefficient of the clutch friction surface is always kept almost constant, and it is possible to effectively prevent shocks or unnecessary clutch slips when the clutch is engaged or disengaged or when the clutch is half-clutch. If it is improved, there is an effect that the simultaneous clutch facing can be effectively protected.

[Brief description of drawings]

FIG. 1 is a block diagram of a clutch control device for a vehicle equipped with an automatic transmission according to the present invention, FIG. 2 is a flowchart showing the flow of the processing, and FIG. 3 is a lubricating oil temperature T and a clutch engagement amount f (T). 4 is a diagram showing the relationship between the oil temperature T and the friction coefficient. 6; flywheel, 8; pressure plate, 9; clutch disc, 10; oil cooler, 12; oil temperature sensor, 13; clutch actuator, 14; electronic control unit.

Claims (1)

[Claims] 1. A clutch controller for a vehicle equipped with an automatic transmission, wherein a wet clutch that lubricates a clutch friction surface with circulating lubricating oil is used, and the clutch is disengaged via a clutch actuator by a controller. With an oil temperature sensor to detect the temperature of
The control device includes a means for obtaining a normal clutch engagement amount, a means for obtaining a correction amount of the clutch engagement amount set in advance based on a signal from the oil temperature sensor, the correction amount and the normal clutch engagement amount. And means for calculating the corrected clutch engagement amount from the above, and further, when connecting the clutch, means for controlling the clutch actuator so that the clutch has the corrected clutch engagement amount. A clutch control device for a vehicle equipped with an automatic transmission.