JP2708984B2 - Control device for front and rear wheel drive vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a two-wheel drive system for driving only one of a front wheel drive shaft system and a rear wheel drive shaft system of a front-rear wheel drive vehicle (so-called four-wheel drive vehicle). The present invention relates to a control device for a front-rear wheel drive vehicle that minimizes friction loss of a drive shaft system that is not transmitted.

[0002]

2. Description of the Related Art A front-rear wheel drive vehicle switches between a four-wheel drive mode in which both front and rear wheels are driven and a two-wheel drive mode in which only front wheels or rear wheels are driven in accordance with a traveling road surface or the like.
Equipped with control device.

[0003] For example, as shown in FIG.
Of the clutch 51 and the transmission 5
2, a transfer 55 for distributing the transmission to the front wheel drive shaft system 53 and the rear wheel drive shaft system 54 when transmitted via
A switching clutch 56 operated by an actuator is provided between the front drive shaft system 53 and a propeller shaft 53a.
And is equipped with. In FIG. 3, reference numeral 53b denotes a front axle, 53c denotes a front wheel, 54a denotes a rear axle,
54b is a rear wheel, and 54c is a universal joint.

During four-wheel drive, the transfer clutch 55 and the front wheel drive shaft system 53 are operated by the switching clutch 56.
To transmit the rotational driving force of the engine 50 to the front wheel drive shaft system 53 and the rear wheel drive shaft system 54. In two-wheel drive, the switching clutch 56 transfers the transfer 55 and the front wheel drive shaft system. 53, and the rotational driving force of the engine 50 is transmitted only to the rear wheel drive shaft system 54.

[0005]

However, according to the control system for a front-rear wheel drive vehicle, the front wheels 53 are used in the two-wheel drive mode in which the rotational drive force is transmitted only to the rear wheel drive shaft system 54.
In addition to the rotation of the front wheel drive shaft system 53c, the front wheel drive shaft system 53 between the front wheel 53c and the switching clutch 56 is also dragged and rotated.
Friction loss has occurred due to the need for rotational power.

[0006] For this reason, when the front and rear wheel drive vehicle is driven by the two wheels by the control device, the fuel efficiency is inferior to that of the two wheel drive vehicle.

Accordingly, an object of the present invention is to reduce the friction loss as much as possible when a two-wheel drive of a front and rear wheel drive vehicle does not rotate the drive shaft system other than the wheels on the side where the rotational driving force is not transmitted. An object of the present invention is to provide a control device for a front and rear wheel drive vehicle.

[0008]

In order to achieve the above-mentioned object, the present invention provides an output of a transmission (10).
A front-wheel drive shaft system (20) and a rear-wheel drive shaft system (40) or a front-wheel drive shaft system for switching a switching clutch (12) so as to transmit to either one of the front-wheel drive shaft system and the rear-wheel drive shaft system. In the control device, the pinion (31) is fixed.
Axle shaft (21) and wheel hub (38)
Is fixed and has a first clutch portion in a plane orthogonal to the axis.
Same as the joint shaft (23).
The pinion (3) is provided axially and rotatable separately.
The gear part which always meshes with 1) and the hollow cylinder part (3
2a), and a gear of the gear (32).
A shaft is rotatable integrally with the gear in a cylinder portion (32a).
Slidably provided in the first clutch unit.
The face clutch part (24b) can be connected and separated
Piston section having a second clutch section in a plane orthogonal to the axis
(24a), and in four-wheel drive, the piston
The part (24a) slides in a predetermined direction and
The latch (24b) is switched to the coupled state, and
By switching the change clutch (12), the transformer
The output of the transmission is the front and rear wheel drive shaft system (20, 4
0), and at the time of two-wheel drive,
By switching the change clutch (12), the transformer
The output of the mission is one of the two drive shaft systems
Not transmitted to (20 or 40), and
The piston portion (24a) of the drive shaft system (20 or 40)
Slides in the opposite direction to the predetermined direction and
To switch the clutch part (24b) to the disengaged state
It was, characterized in that there is provided a control device for a front and rear wheel drive vehicle.

[0009]

According to the present invention, by switching the switching clutch,
In a two-wheel drive mode in which the output of the transmission is transmitted to one of the front wheel drive shaft system and the rear wheel drive shaft system, a clutch mechanism (24) provided on the drive shaft system on the side to which the output of the transmission is not transmitted is provided. The connection between the axle shaft of the drive shaft system and the joint shaft to which the wheel hub is fixed is separated. Therefore, the drive shaft system on the side to which the output of the transmission is not transmitted only rotates with the joint shaft being pulled, and other drive shaft system parts such as other axle shafts do not rotate.

Further, in a four-wheel drive mode in which the output of the transmission is transmitted to both the front wheel drive shaft system and the rear wheel drive shaft system, the clutch mechanism causes the disengaged axle shaft and the joint shaft to move from each other. Are linked.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of a control device for a front and rear wheel drive vehicle according to the present invention. FIG. 1 shows a control device of the present embodiment, which is a drive shaft equipped with a clutch mechanism. FIG. 2 is an enlarged side view of a main part showing a part of the drive wheel portion of the system as a cross section, and FIG. 2 is an explanatory view of a front and rear wheel drive vehicle equipped with the control device of the present embodiment.

As shown in FIGS. 1 and 2, the control system for a front and rear wheel drive vehicle of the present embodiment performs four-wheel drive for transmitting the output of the transmission 10 to the front wheel drive shaft system 20 and the rear wheel drive shaft system 40. , Transfer 11 and front wheel drive shaft system 2
Switching clutch 12 and the front wheel drive shaft system, which separates the transfer 11 and the front wheel drive shaft system 20 during two-wheel drive for transmitting the output of the transmission 10 only to the rear wheel drive shaft system 40. The driving force transmission path between the axle shaft 21 (FIG. 1) of the front axle 36 (FIG. 2) of FIG. 20 and the joint shaft 23 to which the wheel hub 22 (FIG. 1) of the front wheel 37 (FIGS. 1 and 2) is fixed. And a clutch mechanism 24 for connecting and disconnecting the axle shaft 21 and the joint shaft 23 in conjunction with switching of the switching clutch 12.

The axle shaft 21 is rotatably supported by an axle housing 25 as shown in FIG. It is supported by.

The wheel hub 22 and the joint shaft 2
The driving force transmission path to the steering knuckle 2 is
7, a constant velocity joint 30 connected to an end of the axle shaft 21 on the wheel hub 22 side, and a pinion 31 attached to a shaft of the constant velocity joint 30. And a gear portion having a cylinder portion 32a and meshing with the pinion 31.
And a gear 32 having the same.

The clutch mechanism 24 includes a piston portion 24a which is disposed in the cylinder portion 32a of the gear 32 so as to be movable only in the axial direction by engaging with a spline 32b provided on the inner peripheral surface of the cylinder portion 32a. And the piston portion 24
a face clutch 24b, comprising a clutch portion provided on a surface orthogonal to the outer periphery near the axis a and another clutch portion provided on the same surface orthogonal to the outer periphery near the joint shaft 23 to face the clutch portion; And a spring 24c disposed between the joint shaft 23 and the joint shaft 23 and biasing the piston portion 24a in a direction in which the face clutch 24b is disengaged.

The cylinder portion 32a is connected to an air hole 28 provided in the steering knuckle 27 via an air pipe 33. The air hole 28 is connected to a solenoid valve 34 (FIG. 2 ).
Through the air tank 35.

When the solenoid valve 34 is opened during four-wheel drive, compressed air is supplied from the air tank 35 to the cylinder portion 32a through the air hole 28 and the air pipe 33, and the piston portion 24a is 24c
Moves toward the joint shaft 23 against the elastic force of the above, and the face clutch 24b is engaged.

When the solenoid valve 34 is closed during two-wheel drive, the compressed air in the cylinder portion 32a is discharged from the solenoid valve 34, and the piston portion 24a is separated from the joint shaft 23 by the elastic force of the spring 24c. And the face clutch 24b is disengaged.

The switching clutch 12 is not shown, but
The switching operation is performed by an actuator including an air cylinder. The actuator is supplied with compressed air from the air tank 35 via the electromagnetic valve 34. Therefore, at the time of four-wheel drive, the electromagnetic valve 34 is opened, and not only the face clutch 24b is engaged, but also the air tank 35
, Compressed air is supplied to the actuator, and the switching clutch 12 connects the transfer 11 and the front wheel drive shaft system 20 by the actuator. Further, at the time of two-wheel drive, not only the solenoid valve 34 is closed and the face clutch 24b is disengaged, but also the compressed air of the actuator is discharged from the air tank 35, and the switching clutch 12
Disconnects the transfer 11 from the front wheel drive shaft system 20.

In FIG. 2, reference numeral 13 is an engine, 14 is a clutch, 36 is a front axle, 37 is a front wheel, 41 is a propeller shaft, 42 is a universal joint, 43
Is a rear axle, and 44 is a rear wheel. In FIG. 1, reference numeral 38 denotes a wheel.

Next, the operation of the control device for a front and rear wheel drive vehicle will be described.

When the electromagnetic valve 34 is closed and the supply of compressed air from the air tank 35 to the actuator and the cylinder portion 32a is stopped. In two-wheel drive, the switching clutch 12 disconnects the transfer 11 and the front wheel drive shaft system 20 by the actuator. Spring 24c of clutch mechanism 24
Of the joint portion 23 by the elastic force of
And the face clutch 24b is disengaged.

Accordingly, the front wheel drive shaft system 20 is rotated only by the joint shaft 23 and the wheel hub 22 being dragged, and the other axle shaft 21, constant velocity joint 30, pinion 31, gear 32, etc. The drive shaft part does not rotate, so the friction loss is very small,
In terms of fuel efficiency, it is almost the same as a two-wheel drive vehicle.

The solenoid valve 34 is opened, and the air tank 35 is opened.
In the four-wheel drive, the switching clutch 12 connects the transfer 11 and the front wheel drive shaft system 20 by the actuator, while the piston portion 24a of the clutch mechanism 24 uses the elasticity of the spring 24c. The face clutch 24b moves toward the joint shaft 23 against the force and meshes.

Therefore, The output of the transmission 10 is transmitted to both the front wheel drive shaft system 20 and the rear wheel drive shaft system 40.

It should be noted that the present invention is not limited to the embodiment shown in the above-described embodiment, but the point is that the transmission output of the transmission is transmitted to either the front wheel drive shaft system or the rear wheel drive shaft system. In this case, it is sufficient that a clutch mechanism for connecting and disconnecting the axle shaft and the joint shaft is provided on the drive shaft system on the side to which the output of the transmission is not transmitted.

[0028]

As described above, according to the present invention,Next
This has the effects described below.  In two-wheel drive, the output of the transmission
In the drive shaft system on the side that is not transmitted,Face clutch
The joint shaft 23 and the axle shaft 2
Because one side is cut off, Friction loss as much as possible
With less, fuel efficiency can be improved.The face clutch portion 24b is a so-called face type clutch.
Since it is a latch, for example,
As shown in FIG.
Sleeve) 11 is an axial groove in an outer peripheral portion of the wheel side portion 31.
So-called circumferential type that slides into and switches and engages
Movement of the clutch member at the time of switching to constitute the clutch
The moving distance is inevitably large and clutch switching operation is not possible.
Face clutches are more shaft-friendly than those that are more stable.
Movement of the clutch switching coupling
Short working time, stable switching operation, reliability and durability
Will be higher. In addition, the face type clutch has a simple meshing area
Can be adapted to various loads and the application range is wide.
No. Piston part 2 constituting reciprocating part of clutch mechanism
4a is stored in the cylinder portion 32a of the gear wheel 32
The gear wheel 32 and the clutch mechanism 24
Can be miniaturized. For axle shaft pinion and joint axis
And the coaxial gear meshes with it, and decelerates even in this area.
The transmission deceleration rate
The size of the transmission can be reduced, and the transmission can be downsized.
Therefore, the distance between the transmission part and the ground
(Vehicle height) is large enough for off-road vehicles
It can be used to expand the applicable range The reciprocating operation of the piston portion 24a is based on pneumatic pressure and split.
The clutch connection by pneumatic pressure.
The change operation is quick and stable, and the spring
The clutch disengagement operation is stable and the configuration is simple.
Can be downsized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a part of a drive wheel portion of a drive shaft system equipped with a clutch mechanism, which is a control device of the present embodiment.
It is an enlarged side view of a principal part.

FIG. 2 is an explanatory diagram of a front and rear wheel drive vehicle equipped with the control device of the present embodiment.

FIG. 3 is an explanatory view similar to FIG. 2, illustrating a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Transmission 11 Transfer 12 Switching clutch 20 Front wheel drive shaft system 21 Axle shaft 22 Axle hub 23 Joint shaft 24 Clutch mechanism 24a Piston 24b Face clutch 24c Spring 28 Air hole 30 Constant velocity joint 31 Pinion 32 Gear 33 Air pipe 34 Electromagnetic valve 35 Air tank 40 Rear Wheel drive shaft system

Claims (2)

(57) [Claims] 1. The output of a transmission (10)
A front-wheel drive shaft system (20) and a rear-wheel drive shaft system (40) or a front-wheel drive shaft system for switching a switching clutch (12) so as to transmit to either one of the front-wheel drive shaft system and the rear-wheel drive shaft system. In the control device, the axle shaft (2) to which the pinion (31) is fixed is attached.
1), the wheel hub (38) is fixed and the first
Joint shaft (23) having a clutch portion, and coaxially and separately rotatable with the joint shaft (23).
A gear portion provided and constantly meshed with the pinion (31)
(3) having a hollow cylindrical portion (32a)
2) and one of the gears in the cylinder portion (32a) of the gear (32).
The body is provided so as to be rotatable and slidable in the axial direction,
A face clutch that can be brought into and out of contact with the first clutch portion.
Second clutch part in a plane orthogonal to the axis constituting the part (24b)
And a piston portion (24a) having the following configuration. In four-wheel drive, the piston portion (24a)
To connect the face clutch (24b).
The switching clutch (12).
By switching, the output of the transmission changes to the front wheels
And the rear wheel drive shaft system (20, 40), and at the time of two-wheel drive, the switching clutch (12)
By switching, the output of the transmission
Transmitted to one of the two drive shaft systems (20 or 40).
And any one of the drive shaft systems (20 or 40)
The piston portion (24a) is in a direction opposite to the predetermined direction.
To connect the face clutch (24b).
Characterized in that it is switched to the canceling state ,
Control device for front and rear wheel drive vehicles. 2. A control device for a front and rear wheel drive vehicle according to claim 1.
In the above, the piston portion (24a) is pneumatically moved in the predetermined direction.
An air operating mechanism (28, 33) for sliding,
Attach the piston (24a) in the direction opposite to the predetermined direction.
A spring (24c) for biasing is further provided.
Controller before rear wheel drive vehicle according to claim.