JPH01172029A - Controller for four-wheel-drive vehicle - Google Patents

Abstract

PURPOSE:To usually obtain precise transmission torque by providing a pressure detecting means in a hydraulic circuit for an actuator which hydraulic-circuit for an actuator which hydraulic-controls a transfer clutch and feedback- controlling the transmission torque of above-mentioned clutch by the detected signal. CONSTITUTION:A four-wheel-drive vehicle has a transfer clutch 3 which is able to change transmission torque quantity by hydraulic control at the rear end of a transmission directly connected to an engine E and power is transmitted to a rear wheel 4 via the clutch 3. Pressurized oil flowing out of a transfer control valve 9 is supplied via a hydraulic line 11 to the transfer clutch 3 and the valve 9 is controlled by pressurized oil supplied via a pressure regulating side hydraulic line 7 provided with a duty solenoid valve 5. In this case, a hydraulic sensor 12 is provided near the transfer clutch 3 of the hydraulic line 11, and based on its output signal, a duty signal impressed to above-mentioned solenoid valve 5 is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a full-time four-wheel drive vehicle or the like. [Prior art 1] This type of four-wheel drive device is disclosed in Japanese Patent Application Laid-Open No. 58-3083
As described in Publication No. 5 and Japanese Unexamined Patent Publication No. 56-86825, a transfer clutch is provided in the middle of the drive transmission system to the front and rear wheels, and an actuator that hydraulically controls the transfer clutch provides the driving force to the rear wheels. There is a variable torque clutch configuration that performs distribution, and in this case, the transfer pressure is corrected depending on the voltage for driving the actuator and the temperature conditions of the oil in the transmission. [Problems to be Solved by the Invention] However, in the actuator that adjusts the control pressure of the transfer clutch, there are variations in the accuracy of the solenoid valve, and corrections using oil pressure, voltage, etc. are not always performed appropriately. Therefore, the present invention checks the pressure in the hydraulic path connecting the transfer clutch and the actuator and performs feedback control of the transfer pressure, thereby correcting the oil pressure, voltage, etc. based on the variation in accuracy of the strain/idle valve. The present invention aims to provide a control device for a four-wheel drive vehicle that allows values to be corrected. [Means for Solving the Problems] Therefore, in the present invention, a transfer clutch is provided in the middle of the drive power transmission system to the front and rear wheels, and an actuator that hydraulically controls the transfer clutch is used to control the drive force distribution of the drive shaft. In a hydraulic control device equipped with a variable torque clutch, a pressure detection means is provided in an output side hydraulic circuit of the hydraulic control device, and a correction control is performed to correct an input signal to the actuator based on an output signal of the pressure detection means. A means is provided to constitute a feedback control means for preventing changes in the transmitted torque due to temperature changes and voltage changes of the control device. [Function] Therefore, even if there are variations in accuracy in the pressure valve in the actuator, the pressure resulting from control by the actuator is measured by the pressure sensor, and this is fed back to the control means, so voltage changes and temperature changes can occur. This means that the correction value of the transmitted torque depending on (oil temperature) can be corrected appropriately. [Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings. In the figure, reference numeral 1 is a transmission directly connected to the engine E, and front wheels 2 of the automobile are driven by the output taken from the transmission. Further, a transfer clutch 3 is provided at the rear end of the transmission 1, and the amount of transmitted torque can be varied by hydraulic control, and output is transmitted to the rear wheels 4 via the transfer clutch 3. The operating hydraulic circuit of the transfer clutch 3 is configured as shown in FIG. 2, and a duty solenoid valve 5 is provided as an actuator in the pressure regulating side hydraulic path 7 of the pilot valve 6 to control the amount of discharge to the drain 8. That's what I do. The pressure in the hydraulic path 7 acts on the transfer control valve 9, and a switching operation between the drain 10 and the hydraulic path 11 is performed depending on the pressure value. This hydraulic path 11 is
The oil pressure sensor 12 is connected to the oil pressure control chamber 3a of the transfer clutch 3, and is installed near the transfer clutch 3. FIG. 3 shows a transmission control unit, in which the oil pressure sensor 12, throttle opening sensor 13, battery voltage sensor 14, ATF oil filter sensor 15, etc. send signals to an interface circuit 16, from which the A/ A signal is given to the central processing circuit 18 via the D converter 17. Also, vehicle speed sensor (rear wheel rotation speed sensor) 19, vehicle speed sensor (front wheel rotation speed detection) 201, shift range sensor 21, idle switch 22, ist hold switch 23, forced 2WD switch 24, ABS signal sensor 25
etc. provide signals to the central processing circuit 18 via the input interface circuit 26. Further, a constant voltage is applied to the central processing circuit 18 from a constant voltage power supply 27, and an output interface circuit 28 is connected to the central processing circuit 18. A signal is given to the solenoid coil 5a to control the torque transmission force of the transfer clutch 3. Next, feedback control of the control means according to the present invention will be explained with reference to the flowchart of FIG. In the control unit, when a duty signal corrected based on signals from the battery voltage sensor 14, ATF oil temperature sensor 15, etc. is supplied to the solenoid coil 5a of the solenoid valve 5, in step 5101, the central processing circuit At step 18, the transfer pressure corresponding to the set value at that time is retrieved from the memory as a map value. Then, when the above duty signal is output in step 5102, in the next step 5103, the oil pressure sensor 12
Then, measure the transfer operating oil pressure at that time. The result is compared with the above map value in step 5104, and if it is the same as the map value, the process goes to ExIT, but if there is a difference, this is treated as an error in the accuracy of the solenoid valve 5 and the process goes to the next step 5105. Here, it is determined whether the transfer pressure is greater than the map value (-6=), and if it is greater, 1% is subtracted from the value of the duty signal in step 8106, and step 510
If not, 1% is added or subtracted to the value of the duty signal in step 5107, and the process returns to step 5102. In this way, the hydraulic pressure sensor (pressure sensor) 12 provided in the hydraulic pressure path 11 of the transfer clutch allows
By detecting the transfer clutch operating pressure, it is determined whether or not the desired operating pressure is being generated, and the signal can be corrected using feedback control. Effects of the Invention The present invention has been described in detail above, and errors due to variations in accuracy of the solenoid valve that controls transfer 1 pressure are directly captured by transfer pressure detection and feedback control is performed, so that the voltage change is reduced. , appropriate corrections are made to the transmission torque control due to changes in oil temperature, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a four-wheel drive vehicle showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a hydraulic circuit, FIG. 3 is a block diagram of a control unit, and FIG. 4 is a flow chart. 1...Transmission, 3...Transfer clutch, 5...Solenoid valve, 11...Hydraulic pressure path, 12...Hydraulic pressure sensor Patent applicant Fuji Heavy Industries Co., Ltd. Agent Nobu Kobashi Slag amount Patent Attorney Susumu Murai

Claims (1)

[Claims] In a hydraulic control device that includes a transfer clutch in the middle of a drive power transmission system to front and rear wheels, and a variable torque clutch that distributes the driving force to the drive wheels using an actuator that hydraulically controls the transfer clutch, the output of the hydraulic control device A pressure detection means is provided in the side hydraulic circuit, and a correction control means is provided for correcting the input signal to the actuator based on the output signal of the pressure detection means,
A control device for a four-wheel drive vehicle, comprising feedback control means for preventing changes in transmission torque due to temperature changes and voltage changes in the control device.