JPH11165550A - Transfer device for four-wheel drive vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hydraulically control a wet multiple disk clutch by a single oil hydraulic pump, so as to distribute drive force to a front wheel. SOLUTION: In a transfer device for a four-wheel drive vehicle, pressing force of a hydraulically-operated wet multiple disk clutch 4 is controlled, so as to change distribution of drive force. An input shaft 14 of an oil hydraulic pump 17 is connected to an intermediate shaft 2 of an always driven transmission. A shaft 20 of an electric motor 21 is arranged coaxial to the input shaft 14, and the oil hydraulic pump 17 is driven by either one of the intermediate shaft 2 or the electric motor 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device for a four-wheel drive vehicle in which a single hydraulic pump hydraulically controls a wet multi-plate clutch and distributes driving force to front wheels.

[0002]

2. Description of the Related Art In a transfer device for a four-wheel drive vehicle, a wet multi-plate clutch is used to distribute driving force to front wheels.
As a result, the driving force of the front wheels can be freely changed during traveling, and the traveling of the vehicle can be optimized.

[0003] However, the conventional transfer device requires two systems of hydraulic pressure generating devices, a main hydraulic pump driven by a rear wheel drive shaft and a sub hydraulic pump driven by an electric motor. This is because when the vehicle stops, the main hydraulic pump also stops, and it becomes impossible to supply hydraulic pressure, so that the electric motor generates hydraulic pressure from the sub hydraulic pump. The main hydraulic pump alone may be used for normal running of the vehicle, but if the driving force is not transmitted to the front wheels when the vehicle starts, the rear wheels may slip and cannot start. In order to solve this problem, the two-system hydraulic pressure generating device as described above is essential.

As described above, the conventional transfer device requires two hydraulic pumps, which complicates the structure of the hydraulic pressure generating device and increases the manufacturing cost. If all hydraulic pressures are supplied only by a hydraulic pump driven by an electric motor, a large-capacity electric motor is required, resulting in a shortage in the capacity of a power battery of the vehicle.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the object of the present invention is to provide a four-wheel drive vehicle in which a single hydraulic pump hydraulically controls a wet multi-plate clutch and distributes driving force to front wheels. To provide a transfer device.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a configuration of the present invention is a transfer device for a four-wheel drive vehicle in which a driving force distribution is changed by controlling a pressing force of a wet multi-plate clutch by hydraulic pressure. , An input shaft of a hydraulic pump is connected to an intermediate shaft of a transmission that is constantly driven, an electric motor shaft is arranged coaxially with the input shaft, and the hydraulic pump is driven by the intermediate shaft and the electric motor. It is characterized by the following.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, in order to make a conventional two-system hydraulic pump into one system, the auxiliary hydraulic pump is eliminated, and the conventional main hydraulic pump is provided with a one-way clutch and an electric motor. Even when the vehicle is stopped, the hydraulic pump is driven by the electric motor to generate hydraulic pressure, while the vehicle is running, the electric motor is disconnected, and the hydraulic pump is driven by the rear wheel drive shaft. The hydraulic pump is driven by an input shaft connected to the rear wheel drive shaft and an electric motor coaxial with the input shaft. When the vehicle stops,
When the electric motor rotates, the one-way clutch idles, and the hydraulic pump is driven only by the electric motor. When the vehicle runs, the one-way clutch is locked, and the power from the rear wheel drive shaft is transmitted to the hydraulic pump.

When a vane type hydraulic pump is used instead of the external gear type hydraulic pump, a rotating body coaxial with the input shaft of the hydraulic pump rotates and the case is fixed. The case is fixed with a one-way clutch, and the input shaft of the hydraulic pump is driven by an electric motor. When the electric motor rotates while the vehicle is stopped, the one-way clutch idles, and the hydraulic pump is driven by the electric motor. When the vehicle runs, the shaft of the electric motor is locked to the case by a one-way clutch, and the hydraulic pump is driven by the power from the rear wheel drive shaft.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An intermediate shaft 2 of a transmission which constantly receives the rotational force of an engine
, The endless chain 23 is bridged between the gear 3 and a gear 35 of a front wheel drive shaft 34 that transmits a driving force to the front wheels. The right end of the intermediate shaft 2 transmits driving force to the rear wheels via a propulsion shaft (not shown). In order to transmit the rotation of the intermediate shaft 2 to the front wheel drive shaft 34, a wet multi-plate clutch 4 is formed between the intermediate shaft 2 and the gear 3. The wet-type multi-plate clutch 4 has an annular friction plate 7 spline-connected to a case 5 integral with the gear 3 between a number of friction disks 6 spline-connected to the intermediate shaft 2, and a piston 8 of a hydraulic actuator 25. Accordingly, when the friction plate 7 and the friction disk 6 are pressed to the left and frictionally engage with each other, the rotation of the intermediate shaft 2 is transmitted to the gear 3.

The hydraulic actuator 25 is mounted on the wall 2 of the transmission.
4, an annular cylinder 9 arranged concentrically with the intermediate shaft 2,
An annular piston 8 is fitted, and pressure oil is supplied to or discharged from a cylinder 9 from an oil passage 10.

The hydraulic pump 17 for supplying pressure oil to the hydraulic actuator 25 is of an external gear type in the illustrated embodiment, and comprises a gear 18 connected to a shaft 19. The gear 18 is a gear 1 connected to a hollow shaft 20 of an electric motor 21.
6 is engaged. A gear 13 is connected to an input shaft 14 arranged concentrically with the shaft 20 and a gear 12 connected to the intermediate shaft 2.
Is engaged with.

According to the present invention, in order to transmit the rotation of the input shaft 14 to the hydraulic pump 17, the rotating body 26 of the input shaft 14 is used.
Is transmitted to the hollow shaft 20 of the electric motor 21 via the one-way clutch 15. Although the electric motor 21 may be constantly rotated, it is preferable that the electric motor 21 be driven when the rotation of the engine is not transmitted to the hydraulic pump 17 due to the stop of the vehicle. One-way clutch 1
5 is that the rotation of the input shaft 14 is not transmitted to the hydraulic pump 17 when the rotation speed transmitted from the engine to the input shaft 14 via the transmission is smaller than the rotation speed of the hollow shaft 20 of the electric motor 21. The rotation of the input shaft 14 is transmitted to the hydraulic pump 17 via the hollow shaft 20 only when the rotation speed of the input shaft 14 is higher than the rotation speed of the hollow shaft 20.

In the embodiment shown in FIG. 2, the hydraulic pump 17A
Is a rotating body 3 of the input shaft 14 receiving rotation from the intermediate shaft 2 of the transmission in a case 32 connected to the shaft 20 of the electric motor 21.
1, a one-way clutch 33 is supported between the non-rotating part 28 of the apparatus and the shaft 20, and the input shaft 14 and the shaft 24 are driven in opposite directions.

In a normal operation of the vehicle, the electric motor 21 is stopped, and the case 32 is prevented from rotating (locked) by the one-way clutch 33. That is, the case 32 does not rotate because it receives a torque reaction force in the opposite direction to the rotation of the electric motor 21. The rotator 31 is rotated by the input shaft 14 receiving the driving force from the transmission, and thereby the hydraulic pump 17A
Pressure oil is supplied to each section such as the hydraulic actuator 25.

When the vehicle stops, the rotation of the input shaft 14 is stopped, and when the electric motor 21 is rotated, the case 32 is rotated by the shaft 20, and hydraulic oil is supplied from the hydraulic pump 17A to the hydraulic actuator 25 and the like. You.

[0016]

As described above, the present invention relates to a transfer device for a four-wheel drive vehicle in which the driving force distribution is changed by controlling the pressing force of a wet multi-plate clutch by hydraulic pressure.
The input shaft of the hydraulic pump is connected to the intermediate shaft of a constantly driven transmission, and the shaft of the electric motor is arranged coaxially with the input shaft.
The hydraulic pump is driven by the intermediate shaft and the electric motor. By using two conventional hydraulic pumps as one system, the transfer device can be simplified and manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a schematic configuration of a main part of a transfer device of a four-wheel drive vehicle according to the present invention.

FIG. 2 is a side sectional view showing a schematic configuration of a main part of a transfer device of a four-wheel drive vehicle according to a modified embodiment of the present invention.

[Explanation of symbols]

2: intermediate shaft 3: gear 4: wet multi-plate clutch 5: case 6: friction disk 7: friction plate 8: piston 9:
Cylinder 10: Oil path 12: Gear 13: Gear 14: Input shaft 15, 33: One-way clutch 16: Gear 17, 17A: Oil pump 18: Gear 19: Shaft
20: Hollow shaft 21: Electric motor 23: Endless chain 24: Wall 25: Hydraulic actuator 26: Rotating body 28: Non-rotating part 31: Rotating body 32: Case
34: front wheel drive shaft 35: gear

Claims (2)

[Claims] 1. An intermediate shaft of a transmission in which an input shaft of a hydraulic pump is constantly driven in a transfer device of a four-wheel drive vehicle in which a driving force distribution is changed by controlling a pressing force of a wet multi-plate clutch by hydraulic pressure. , A shaft of an electric motor is arranged coaxially with the input shaft, and the hydraulic pump is driven by the intermediate shaft and the electric motor. 2. The transfer device for a four-wheel drive vehicle according to claim 1, wherein a one-way clutch is provided between a shaft of said electric motor and said input shaft.