JPH03186412A - Suspension device of vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a suspension device for a vehicle having leaf springs that support a common axle member having left and right rear wheels attached at both ends (prior art). A vehicle suspension device proposed by the applicant and disclosed in Japanese Patent Application Laid-Open No. 63-212109 is movable in the longitudinal direction of the vehicle with its front and rear ends supported by shackle members rotatably attached to the vehicle body frame. The left and right pairs of double shackle leaf springs are arranged on the left and right sides, and when the front wheels are steered, these left and right leaf springs are moved forward and backward in opposite directions by an actuator, thereby causing the rear wheels to move forward and backward. The front wheels are steered in the opposite phase or in the same phase as the front wheels, thereby improving turning performance when the vehicle is running at low speeds and improving running stability when the vehicle is running at high speeds.

By the way, in such a suspension device, when the pair of left and right leaf springs are moved in the longitudinal direction in the same direction (in phase) with each other by the actuator, the wheel path can be changed. However, in vehicles equipped with suspension devices like this, driving stability can be improved by extending the wheelbase when driving straight at high speed, and by shortening the wheelbase when turning. The ability to turn can be improved.

However, in a rear wheel drive vehicle, if the wheelbase is changed while the vehicle is running, a problem arises in that the driving force of the rear wheels changes. In other words, when moving the rear axle backwards to lengthen the wheelbase while driving at a constant speed, the driving force of the rear wheels increases rapidly, accelerating the vehicle body, and also moving the rear axle forwards. When the wheelbase is shortened, the driving force of the rear wheels decreases rapidly and the vehicle decelerates. Such a change in vehicle speed not only causes discomfort to the occupants, but also a sudden increase in rear wheel driving force, especially when the wheelbase is extended, may be dangerous.

(Object of the Invention) Therefore, the present invention aims to prevent acceleration and deceleration of the vehicle body due to a change in the wheelbase in a vehicle equipped with a rear end suspension device whose wheelbase can be changed by an actuator while driving. With the goal.

(Structure of the Invention) The present invention is characterized by providing a driving force control means that can change the driving force of the rear wheels when the wheel base is changed by the actuator.

(Effects of the Invention) According to the present invention, when the wheelbase is extended, the driving force of the rear wheels is reduced to prevent sudden acceleration of the vehicle body, and when the wheelbase is shortened, the driving force of the rear wheels is increased to prevent the vehicle body from accelerating suddenly. Since the occurrence of sudden deceleration can be prevented, it is possible to prevent changes in vehicle body speed when changing the wheelbase and improve ride comfort.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically showing an embodiment of a vehicle suspension device according to the present invention, together with a front wheel steering mechanism of an automobile to which the suspension device is applied. In FIG. 1, a front wheel steering 8g lateral 5 is provided to steer the left and right front wheels 2L, 2R in accordance with the steering by the steering wheel 3, and this front wheel steering mechanism 5 rotates the front ends 2L, 2R. A pair of knuckle members 6 that are freely supported, a pair of tie rods 8 each having one end connected to the knuckle arms 6a of these knuckle members 6, and a rank having the other ends of the pair of tie rods 8 connected to both ends thereof. rank and with axis 9
The steering gear mechanism 10 is of a pinion type.

The left and right rear ends 12L and 12R are rotatably attached to both ends of an axle member 20 extending in the vehicle width direction to which the driving force of the propeller shaft 16 is transmitted via the differential gear device 14.

The vehicle body frame 22, whose front side is omitted in FIG. 1, has a pair of shank members 26L at predetermined left and right positions on its rear side, as is clear from FIGS. 2 and 3. 26R is body frame 2
A pair of shank members 28L, 28R are installed at predetermined left and right positions in front of the positions where the shackle members 26L, 26R are installed in the vehicle body frame 22.
is rotatably attached at its upper end by a shaft 29. The rear ends of leaf springs 30L, 3OR are attached to the lower ends of the shackle members 26L, 26R, and the leaf spring 30L is attached to the middle part of the shackle members 28L, 28H.

The front end of 30R is installed and leaf spring 3OL
, 30R is the shackle member 2617.26R28L,
28R so as to be movable in the longitudinal direction of the vehicle body.

Below the leaf springs 3OL and 30R, a pair of brackets 24 fixed to the axle part 20 are arranged, and in the middle of the leaf springs 30L and 30R,
As is clear from FIG. 3, the through holes 32 are formed in the vertical direction. The bracket 24 and the leaf spring 30 [1, 3OR are the bolts 34 inserted through the transparent holes 32:! Concluded by Erbisyl I-35. In addition, the axle member 20 and the leaf spring 30I7 are located at the position sandwiching the syl-35 in the front and back direction on the upper surface of the leaf springs 30[,,3OR.
．． 30R is fixed to the bullet part 4-3G for preventing the rear wheel 12+4.12R from colliding with the vehicle body frame 22 due to L-down vibration.

Soya nocle member 28+7 that supports the vehicle body frame 224
．． A pair of right hydraulic cylinders 38L and 38R are installed via brackets 39L and 39R at a predetermined position on the front side of the position where 28R is removed.
Piston rods 40*1.40R extending from the hydraulic cylinders 38L and 38R have their ends attached to the lower ends of the shackle members 28L and 28R, respectively.

Therefore, when the piston rod 4011.40R protrudes from the hydraulic cylinders 38L, 38R, the shank members 28L, 28R and the shackle members 26L, 2
6R rotates about shafts 29 and 27, respectively, and as a result, leaf springs 30L and 30R move toward the rear of the vehicle body, extending the wheel heath. In addition, the piston rod 4015.40R is the hydraulic cylinder 38L,
When pulled into 38R, leaf spring 3
0L1.30R moves to the front of the vehicle body, shortening the wheel height.

The hydraulic cylinder 38L2.38R has a piston rod 40
Hydraulic chambers 38a and 38b are respectively partitioned by a piston 41 fixed to I7.40R, and these hydraulic chambers 38a and 38b communicate with each other via an oil passage 45. The oil passage 45 is provided with an oil pump 46I7.46R controlled by the control unit 50.

In addition, a clutch 60 is provided in the middle of the propeller shaft 16, and when this clutch 60 is operated, the driving force is transmitted from the propeller shaft 16 to the rear wheels 1211.121?4. is reduced or blocked.

The control unit 50 includes a steering angle sensor 4J that is arranged in relation to the front wheel steering mechanism 5 and detects the steering angle θ of the front wheels 2L and 2R.
Detection signal Sθ from 52 and front wheel 2L.

(or 2I?) Detection No. 13 SV is supplied from a medium speed sensor 54 that detects the vehicle speed based on the rotation speed. Based on the detection signals Sθ and S■, the control unit 50 outputs control signals Sff and Sr to the oil pumps 46L and 46R in order to operate the hydraulic cylinders 38I1.38R.

For example, the oil pump 4615.46R receives the control signal 51
When 1Sr takes a predetermined height, the hydraulic cylinder 38
Hydraulic chamber 38 from each hydraulic chamber 38a of I7.38R
1) Introduce oil to the piston rods 40L, 40
R is retracted into the hydraulic cylinders 38L, 38R, thereby shortening the wheelbase, and the control signal S7! ,
When Sr takes a predetermined low level, the hydraulic cylinder 38L
, 38R are introduced into the hydraulic chamber 38a from the respective hydraulic chambers 38b, and the piston rods 40L, 40R are protruded from the hydraulic cylinders 38L, 38R, thereby extending the wheel heath.

In addition, the control 1 unit 50 sends low level control signals Sf and Sr to the oil pump 46 when extending the wheel height.
When outputting to 1.46R, at the same time, Cura and Chiro 0
A drive signal Sc is supplied to the clutch 60 to operate the clutch 60. By the operation of this clutch 60, the rear wheels 12L,
The driving force for 12R is reduced or cut off to prevent acceleration of the vehicle body when the wheelbase is extended.

Although illustrations and detailed explanations are omitted, the propeller shaft 16 is provided with a spline joint that allows the length of the propeller shaft 16 to be changed, and allows for movement of the axle member 20 in the longitudinal direction of the vehicle body. is absorbed by the spline joint.

The above explanation has clarified the structure and operation of one embodiment of the vehicle suspension device according to the present invention. In the above embodiment, the clutch 60 is installed in the middle of the propeller shaft 16 as a rear wheel drive force control means. By providing this clutch, the driving force of the rear wheels 12L and 12R is reduced or cut off when the wheelbase is extended, but instead of providing the clutch 60, an engine output control means that reduces the engine output when the wheelbase is extended may be provided. By using this engine output control means, it is also possible to increase the engine output when the wheelbase is shortened, thereby preventing deceleration of the vehicle body.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram schematically showing an embodiment of a vehicle suspension device according to the present invention, together with a front wheel steering mechanism of an automobile to which the suspension device is applied, and FIGS. 2 and 3 are perspective views of the main parts thereof. FIG. 3 is a diagram and a side view. 2L, 2R - front wheel 12L, 12R - rear wheel 20 -
Axle member 22-body frame 26L, 26
R, 28L, 28R---Shankle member 30L, 30R-Leaf spring 38L, 38R-Hydraulic cylinder 46L, 46R---Oil pump

Claims (1)

[Scope of Claims] 1. A pair of left and right double shackle leaf springs whose front and rear ends are supported by shackle members rotatably attached to the vehicle body frame and are disposed so as to be movable in the longitudinal direction of the vehicle; A suspension of a vehicle configured such that the pair of leaf springs are moved forward and backward in the same direction by an actuator, thereby moving the rear axle supported by the leaf springs back and forth, thereby changing the wheelbase. A suspension device for a vehicle, characterized in that the device is provided with a driving force control means that can change the driving force of the rear wheels when the wheel base is changed by the actuator. 2. The suspension device according to claim 1, wherein the driving force control means reduces the driving force of the rear wheels when the wheel base is extended by the actuator.