JPH01122728A - Hydraulic clutch control device - Google Patents

Abstract

PURPOSE:To restrain heat generation from a hydraulic clutch which transmits a torque in accordance with a fed hydraulic pressure and to enhance the reliability by controlling the hydraulic pressure fed into the hydraulic clutch so that a heating value is set to be less than a predetermined value. CONSTITUTION:The output shaft of a transmission 12 integrally incorporated with an engine 11 is coupled with right and left front wheels 15F through a parallel gear mechanism 13 and a front differential gear mechanism 14, and are also coupled to right and left rear wheels 15R through a bevel gear mechanism 16 and a hydraulic multiple disc clutch 17. Further, rotational speed sensors 19i, 19o and a torque sensor 32 are respectively provided on input and output shafts of the clutch 17, and are connected to a control unit 20. Further, the clutch 17 transmits a torque in accordance with a fed hydraulic pressure. In this arrangement, hydraulic pressure fed into the clutch 17 is controlled so that the heating value of the clutch 17 is set to be less than a predetermined value.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a control device for a hydraulic clutch, particularly a control device for a hydraulic clutch used as a transfer clutch of a single front and rear wheel drive vehicle or a differential limiting clutch of a final reduction gear. Regarding.

(Prior Art) In automobiles, a differential gear is provided with a differential limiting clutch to limit differential differential between the left and right drive wheels, and in four-wheel drive vehicles that drive both front and rear wheels, A transfer clutch is provided to control the driving force distribution ratio between the front and rear wheels. In recent years, clutches used in such automobiles are composed of hydraulic multi-plate clutches, and the control of transmission torque is facilitated. The hydraulic multi-disc clutch used to limit the differential or control the driving force distribution ratio between the front and rear wheels as described above generally controls the hydraulic pressure to adjust the rotational speed difference Δω of the input and output shafts and the transmission torque T to the fifth Maintain a proportional characteristic as shown by the dashed line in the figure.

(Problems to be Solved by the Invention) However, in the hydraulic multi-disc clutch as described above, in order to control the rotational speed difference Δω and the transmitted torque T to have proportional characteristics, as shown in FIG. Another problem is that the amount of heat generated Q increases significantly in a region where the transmitted torque T is large, resulting in an overheating state.

This invention has been made in view of the above problems, and provides a hydraulic clutch control device that controls the hydraulic pressure supplied to the hydraulic clutch so that the amount of heat generated is below a predetermined value, and aims to improve its reliability. The purpose is to

(Means for Solving the Problems) A hydraulic clutch control device according to the present invention is a hydraulic clutch that transmits torque corresponding to supplied hydraulic pressure from an input shaft to an output shaft, in which the hydraulic pressure is transmitted to a predetermined calorific value. The gist is to control it so that it is as follows.

(Function) According to the hydraulic clutch control device according to the present invention, the hydraulic pressure supplied to the hydraulic clutch is controlled so that the amount of heat generated by the hydraulic clutch is equal to or less than a predetermined value. This prevents the device from overheating, resulting in high reliability.

(Example) Embodiments of the present invention will be described below based on the drawings.

1 to 4 show a hydraulic clutch control device according to an embodiment of the present invention, in which FIG. 1 is a schematic diagram of a power transmission system of a front and rear wheel drive vehicle, FIG. 2 is a sectional view of a transfer clutch, FIG. 3 is a circuit diagram of the control device, and FIG. 4 is a flowchart.

In the if diagram, 11 is the engine, 12 is the engine 11
The output shaft of the transmission 12 is connected to the left and right front wheels 15F via a parallel gear mechanism 13 and a front wheel differential mechanism 14, and a bevel gear mechanism 16 and a hydraulic multi-plate clutch 17. and is connected to the left and right rear wheels 15R via a rear wheel differential mechanism 18. The hydraulic multi-disc clutch 17 has rotational speed sensors 19 on the input shaft and output shaft that detect the rotational speed, respectively.
i, 19o are provided, and a torque sensor 32 is provided on the input shaft, and these rotational speed sensors 19i, 19o are provided.
o and torque sensor 32 are the controls) 20
It is connected to the.

The rotational speed sensors 19i and 19o each detect the rotational speed of the input shaft and the output shaft, and output a detection signal representing the rotational speed to the control unit 20. Further, the torque sensor 32 is composed of a non-contact sensor such as a magnetostrictive sensor, detects the input shaft torque, that is, the transmission torque of the clutch 17, and outputs a detection signal representing the transmission torque to the control unit 20. The control unit 20 includes an electric control circuit composed of a one-chip microcomputer, etc., and a hydraulic circuit 35 driven by the electric control circuit.
(described later), and each of the above-mentioned sensors 19i, 19o, -
The hydraulic multi-disc clutch 17 is controlled based on the output signal of 32.

As shown in FIG. 2, the hydraulic clutch 17 has an input shaft 22 and an output shaft 23 coaxially supported in a hollow housing 21 on the left and right sides in the figure, respectively. The input shaft 22 is mounted in the housing 21 on the right side in the figure with a needle bearing 24a.
, 24b, and is rotatably supported through the housing 21
The driven bevel gear of the bevel gear mechanism 16 described above is fixed to the right end in the drawing that protrudes from the top, and the clutch drum 25 is spline-coupled to the left end in the drawing. The output shaft 23 has a pole bearing 27a inside the housing 21.

A hollow shaft 26 rotatably supported by 27b is fitted, and the left end in the figure protrudes outside the housing 21 and is connected to the rear wheel differential mechanism 18, and is held at the right end in the figure. Part 2
8 are spline-coupled. A plurality of drive plates 29 are spline-coupled to the inner circumference of the clutch drum 25.

A plurality of driven plates 30 are provided on the outer periphery of the holding member 28.
are connected by splines. These plays) 29.3
0 are arranged alternately in the axial direction so as to be able to make frictional contact, and a pressing member 31 is pressably engaged on the left side in the figure. The pressing member 31 is supported so as to be movable in the axial direction on the outer circumference of the hollow shaft 26, and the above-mentioned pole bearing 27 is attached to the left end in the figure.
The piston 33 is engaged via b. piston 33
is supported by the inner circumferential wall of the housing 21 so as to be slidable in the axial direction, and defines an oil chamber 34 between the inner circumferential wall of the housing 21 and communicating with a hydraulic control circuit to be described later via an oil passage 21a. This piston 33 presses the plates 29, 30 via the pressing member 31 with a force corresponding to the oil pressure in the oil chamber 34.

The hydraulic control circuit 35, as shown in FIG.
The pump 37 driven by pressurizes and discharges the oil in the reservoir tank 38, and the pressure oil discharged by the bomb 37 is stored in the accumulator 39, and is controlled by the center-close type "Wt magnetic pressure control valve 40. The motor 36 is connected to the control unit 20, the accumulator 39 is provided with a pressure sensor 41 connected to the control unit 20, and the motor 36 is connected to the pressure sensor 41. It is controlled based on the oil pressure detected by and is activated when the oil pressure falls below a predetermined value. 42 is a one-way valve.

The pressure control valve 40 has an inlet port 43i connected to the accumulator 39, a drain port 43d connected to the reservoir tank 38, an outlet port 430 connected to the oil chamber of the hydraulic multi-disc clutch 17, and a control port 4.3c connected to the valve body 43. A spool 44 formed in the valve body 43 and slidably housed in the valve body 43 is energized by a solenoid 45 connected to the control unit 20, and the hydraulic pressure H supplied from the outlet port 430 to the hydraulic multi-disc clutch 17 is applied to the solenoid 45. linearly control the current value applied to the That is, this pressure control valve 40 causes the hydraulic pressure in the oil chamber 34 of the hydraulic multi-disc clutch 17 led through the control port 43c and the biasing force of the solenoid 45 to act against the spool 44, thereby controlling the hydraulic multi-disc clutch 17. The hydraulic pressure supplied to the oil chamber 17 is maintained at a value corresponding to the current value supplied to the solenoid 45.

Next, the operation of this embodiment will be explained with reference to FIG.

This hydraulic clutch control device controls the hydraulic pressure H supplied to the hydraulic clutch 17 by repeating a series of processes shown in the flowchart of FIG.
Controls the driving force distribution ratio of 5F and 15R.

First, when the ignition key is turned ON, after initialization processing, in step 1, the rotation speed sensor 19
f, 19o and the output signal of the torque sensor 32, and in step P2, the rotation speed sensor 1
The rotational speed difference Δω between the input and output shafts 22 and 23 of the hydraulic multi-disc clutch 17 is calculated from the output signals of 9i and 19o. In the subsequent step P3, the value of the flag F is determined, and if the flag F is O, the target transmission torque T (T=f(Δω)) is determined in correspondence with the rotational speed difference Δω in step P4, and the step In step P5, the expected heat generation amount Q is calculated by multiplying the target transmission torque T and the rotational speed difference Δω, and if the flag F is 1, in step P6, the target transmission torque Tp and rotational speed calculated during the previous routine execution are calculated. The expected heat generation ff1Q is calculated by multiplying by the difference Δω. It goes without saying that the target transmission torque T in step P3 can be determined by either a table lookup method or an algorithm.

Next, in step P7, the expected calorific value Q is set to a predetermined value Q.
It is determined whether the expected heat generation 1 Haruka Q is less than the predetermined value QO, the flag F is set to O in step P8, and if it exceeds the predetermined value QO, the previous routine is executed in step P3. After correcting to increase the torque T by adding a predetermined value α to the target transmission torque Tp at step PI
Set flag F to 1 at O. In step File,
Determine the oil pressure H based on the target transmission torque T Next, in step P12, the deviation ΔT (ΔT = l
Determine the magnitude of Tp - Ts l). In this step P12, if the deviation ΔT is smaller than a predetermined value (-@), the process of step P15 is performed after the process of step P13, and if the deviation ΔT is within a predetermined range (-ε≦ΔT≦ε), the process is performed directly. The process of step P15 is performed, and if the deviation ΔT is larger than the predetermined value ε, step P1 is performed after step P14.
In step P13, a predetermined value Δh is added to the oil pressure H to increase the oil pressure H. In step P14, the oil pressure H is reduced by a predetermined value Δh, and in step P15, the oil pressure is corrected to decrease. Then, in step P1B, the target transmission torque T is stored as comparison data Tp in preparation for the next execution of the routine. Thereafter, a series of processes are repeatedly executed at a predetermined period.

As mentioned above, in the control device of this embodiment, the input/output shaft 2
2. Target transmission torque T based on the rotational speed difference Δω between
is determined and the hydraulic multi-disc clutch 17 is controlled. However, if it is expected that the amount of heat generated Q is excessive, the transmitted torque is increased so that the amount of heat generated does not exceed a certain value, as shown by the solid line in Fig. 5. As a result, the amount of heat generated is suppressed and high reliability is achieved.

In FIG. 5, the broken line indicates a line in which the calorific value Q, that is, the torque T, the rotational speed Δω, and the product T×Δω are constant, and in particular, in this embodiment, the detected transmitted torque Ts
is compared with the target transmission torque T, and the command value is corrected based on the comparison result. Therefore, it is possible to compensate for individual variations in the characteristics of the hydraulic multi-disc clutch 17 or deterioration due to wear, etc., resulting in higher reliability. It will be done.

In addition, in the above-mentioned embodiment, a hydraulic multi-disc clutch used as a transfer clutch for a front-wheel drive vehicle is shown.
It goes without saying that the present invention can also be applied to hydraulic multi-plate clutches used as differential limiting clutches in differential gears, and can also be controlled not only to keep the amount of heat generated constant, but also to reduce the amount of heat generated. It goes without saying that there is nothing you can do.

(Effects of the Invention) As explained above, according to the hydraulic clutch control device according to the present invention, the hydraulic pressure supplied to the hydraulic clutch is controlled so that the amount of heat generated is equal to or less than a predetermined value, so that high reliability can be achieved. can get.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the hydraulic clutch control device according to the present invention, in which FIG. 1 is a schematic diagram of a power transmission system, FIG. 2 is a cross-sectional view of the hydraulic clutch, and FIG. 3 is a hydraulic clutch diagram. The circuit diagram and FIG. 4 are flowcharts. FIG. 5 is a diagram showing the control characteristics of the hydraulic clutch, and FIG. 6 is a diagram showing the heat generation characteristics. 11...Engine 17...Hydraulic multi-plate clutch 19i, 19o...Rotational speed sensor 20...Control unit 29...Drive rate 30...Driven plate 32...Torque sensor Patent application Person Honda Motor Co., Ltd. Agent
Patent Attorney, Part 2 1) Patent Attorney, Kuni Ohashi, Part 1, Patent Attorney, Udou Koyama, Part 1)
Shigeru Figure 5 Figure 6 0 I Yun Run f-+v R T

Claims (1)

[Scope of Claims] A hydraulic clutch that transmits torque corresponding to supplied hydraulic pressure from an input shaft to an output shaft, characterized in that the hydraulic pressure is controlled so that the amount of heat generated is below a predetermined value. Control device.