JPH0668910U - Rear axle support device for vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to increase the rear-axle cornering force when turning the vehicle to obtain stable turning performance. [Structure] The upper front side is supported by a vehicle body 9 via an upper link 8, and the lower left and right lower sides are connected to the vehicle body by a lower link 20 via a support 19, and the upper rear side lower link 2 is connected.
The rear axle 7 is supported by the vehicle body 9 via the lateral link 16 above 0, and the lower link 20 has its rear side located on the upper side, and its plane shape is the rear axle 7.
The mounting widths on the vehicle body 9 side are narrower than the mounting widths on the vehicle body side, and they are formed to have a substantially V shape, while the upper link 8, the lower link 20, and the lateral link 16 are pivotally connected to each other. The bushes made of an elastic body are provided in the respective portions, and the bushes provided in the rear axle 7 side turning connection portion of the lateral link 16 are formed to have a laterally low elastic force.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rear axle support device for a vehicle, and more particularly to a technique for improving the maneuverability and stability of the vehicle.

[0002]

[Prior art]

 BACKGROUND ART Conventionally, as a rear axle support device in which a leaf spring is interposed in a vehicle such as a truck, a technique is known in which an understeer characteristic is provided by a cornering force to increase stability during turning of the vehicle (actual opening flatness). No. 4-45106).

Further, as a rear shaft support device in which an air spring is interposed, there is known a rear shaft support device as shown in FIGS. 14 and 15 (see Automotive Engineering Bulletin vol 45, No. 3). In the figure, a central upper portion of the rear axle 1 is supported by the vehicle body 3 via a pair of upper links 2 which are provided on both sides and which are substantially V-shaped. Further, the left and right lower portions of the rear axle 1 are connected to the vehicle body 3 via a pair of lower links 5 which are parallel to each other via supports 4, respectively. Further, an air spring 6 is interposed between the support 4 and the vehicle body 3.

[0004]

[Problems to be solved by the device]

 However, in the conventional rear axle support device as shown in FIGS. 14 and 15, since the rear axle 1 does not steer (neutral steer) when the vehicle turns, the rear axle cornering force during turning does not increase. It was not possible to expect, and there was the problem that stable turning performance could not be obtained due to tail flow and the like for sudden turning.

In view of the conventional problems as described above, the present invention increases the rear axle cornering force at the time of turning of the vehicle and obtains stable turning performance.

[0006]

[Means for Solving the Problems]

 Therefore, according to the present invention, the upper front side is supported by the vehicle body through the upper link, the lower left and right lower portions are connected to the vehicle body by the lower link through the support, and the upper side of the upper rear side above the lower link is lateral. A rear axle supported by the vehicle body via a link is provided. The lower link is positioned so that its rear side is located on the upper side, and the plane shape of the lower link is substantially V-shaped relative to the rear axle-side mounting width. The upper link, the lower link, and the lateral link are formed into a V-shape, and elastic bushes are respectively provided at the pivotal connection portions of the upper link, the lower link, and the lateral link, and the lateral link is pivoted on the rear axle side. The bush inserted in the connecting part has a shape with a low elastic force in the lateral direction.

[0007]

[Action]

 In such a configuration, since the rear axle becomes oversteer at the start of turning, there is less delay in steering at the start of turning, and the rear axle becomes understeer at the time of turning, and cornering force increases, so stability at the time of turning increases. .

[0008]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 to 3, the central upper portion of the rear axle 7 is supported by the vehicle body 9 via a single upper link 8 extending forward of the vehicle. In this case, ring portions 8a are formed at both ends of the upper link 8 as shown in FIG. 4, and a cylindrical elastic bush, for example, a rubber bush 10 is fitted and fixed to the inner peripheral surface of both ring portions 8a. The inner cylinder 11 is fitted on the inner peripheral surface of the rubber bush 10. A pair of brackets 12 on both sides are formed so as to project obliquely upward at the center upper part of the rear axle 7, and a pair of brackets 13 on both sides are formed so as to project horizontally rearward on the vehicle body 9 side.

The ring portion 8a on the front end side of the upper link 8 is inserted between the bracket portions 13 on the vehicle body 9 side, and the mounting rod 14 having a threaded portion on the tip portion is attached to one of the bracket portion 13 and the rubber portion. The inner cylinder 11 of the bush 10 and the other bracket portion 13 are inserted in this order, and the nut 15 is fitted to the male thread at the tip of the mounting rod 14 to connect the upper link 8 and the vehicle body 9 (see FIG. 4). .

Further, the rear end side ring portion 8a of the upper link 8 is inserted between the bracket portions 12 on the rear axle 7 side, and like the front end side ring portion 8a of the upper link 8, the front end portion has a screw thread. A mounting rod having a portion is inserted in the order of the one bracket portion 12, the inner cylinder 11 of the rubber bush 10 and the other bracket portion 12, and a nut is fitted to the tip of the mounting rod to fit the upper rod. The link 8 and the rear axle 7 are connected.

An upper rear side of the rear axle 7 above a lower link 20 described later is supported by the vehicle body 9 via a lateral link 16. The structure of the lateral link 16 will be described with reference to FIGS. The lateral link 16 is composed of a tube. Ring portions 16A and 16B are provided at both ends of the lateral link 16.

The ring portion 16B includes a cylindrical outer cylinder 16a, a cylindrical elastic bushing, such as a rubber bush 16b, which is fitted and fixed to the inner peripheral surface of the outer cylinder 16a, and an inner peripheral surface of the rubber bush 16b. And a cylindrical inner cylinder 16c fitted to The other ring portion 16A is fitted into an elongated cylindrical outer cylinder 16d, an oblong rubber bush 16e fitted and fixed to the inner peripheral surface of the outer cylinder 16d, and a center hole of the rubber bush 16e. And a cylindrical inner cylinder 16f. In this case, semicircular curled portions 16g are formed at two positions of the oblong rubber bush 16e that face each other in the longitudinal direction, and the rubber bush 16e has a laterally low elastic force. Is formed.

A bracket portion 17 is formed at an upper center of the rear axle 7, and a mounting rod portion 17a is formed to project from the bracket portion 17 toward the rear of the vehicle. On the vehicle body 9 side, a pair of bracket portions 18 on both sides are formed so as to project downward. Then, the rubber bush 16b of the one ring portion 16B of the lateral link 16 is inserted between the bracket portions 18 on the vehicle body 9 side, and the mounting rod 22 having a threaded portion at the tip end is attached to the one bracket portion 18 The cylinder 16c and the other bracket portion 18 are inserted in this order, and the nut 23 is fitted to the male screw portion at the tip of the mounting rod 22 to connect the lateral link 16 and the vehicle body 9.

The inner cylinder 16f of the rubber bush 16e of the other ring portion 16A of the lateral link 16 is inserted into the mounting rod portion 17a on the rear axle 7 side, and a nut is attached to the male screw portion at the tip of the mounting rod portion 17a. 24 is fitted to connect the lateral link 16 and the rear axle 7. The lower left and right sides of the rear axle 7 are connected to the vehicle body 9 by a lower link 20 via a support 19.

That is, below the left and right portions of the rear axle 7, supports 19 extending in the vehicle front-rear direction are provided, respectively. Air springs 21 are interposed between the upper surfaces of the front and rear portions of the support 19 and the lower surface of the vehicle body 9, respectively. The pair of lower links 20 are configured such that their rear portions are located on the upper side and their planar shapes are substantially V-shaped so that the mounting width on the vehicle body 9 side is narrower than the mounting width on the rear axle 7 side. It Ring portions are respectively formed at both ends of each lower link 20, and cylindrical rubber bushes (not shown) are fitted and fixed to the inner peripheral surfaces of both ring portions, and inner cylinders are formed on the inner peripheral surfaces of the rubber bushes. It is fitted. Although not shown, a mounting rod portion having a threaded portion on the tip end is formed on the outer surface of the front end portion of the support 19, and the tip end male threaded portion is similarly formed on the vehicle body 9 side. A mounting rod portion having a protrusion is formed.

Then, the inner cylinder of the rubber bush of the ring portion on the rear end side of the lower link 20 is inserted into the mounting rod portion on the support 19 side, and the nut is fitted to the male screw portion at the tip of the mounting rod portion. Together, the lower link 20 and the support 19 are connected. Similarly, the inner cylinder of the rubber bush of the ring portion on the front end side of the lower link 20 is similarly inserted into the mounting rod portion on the vehicle body 9 side, and the nut is fitted to the male screw portion at the tip of the mounting rod portion. Then, the lower link 20 and the vehicle body 9 are connected.

Next, the operation of this configuration will be described. When the vehicle starts to turn in the direction shown in FIG. 7, the cornering force acts on the vehicle. At this time, the positions of the rear axle 7 side rotary connection portion (pivot portion) A of the lateral link 16 and the support 19 side rotation connection portion (pivot portion) B, C of the lower link 20 which are laterally low in elastic force are displaced. . As a result, the rear axle 7 is steered to the oversteer side where the rear-shaft steer angle becomes the-side as shown in FIG. 8 (see FIG. 9X).

When the roll of the vehicle body 9 gradually increases, the position of the vehicle body 9 side (front side) pivotal connecting portion (pivot portion) E of the lower link 20 on the outside of the turn is low, and the vehicle body side of the lower link 20 on the inside of the turn ( The position of the (front side) rotation connecting portion (pivot portion) D becomes higher. Since the length of the lower link 20 does not change, the rear axle 7 is eventually pulled forward on the outside of the turning and pulled backward on the inside of the turning.

As a result, as shown in FIG. 8, the rear axle 7 is steered to the understeer side where the rear axle steer angle is on the + side (see FIG. 9Y). As described above, since the rear axle 7 has the oversteer characteristic at the start of turning, the delay in steering at the start of turning is reduced, and the rear axle 7 has the understeer characteristic at the time of turning, and the tires and the road surface on the rear axle side are reduced. The slip angle increases and the cornering force increases. Therefore, stable vehicle turning performance can be obtained.

10 to 13, the rear axle 7 side pivotal connection portion (pivot portion) A of the lateral link 16, the support side pivotal connection portions (pivot portion) B and C of the lower link 20 and the lower link 20 are shown. 3 shows changes in the positions of the vehicle body 9 side (front side) rotation connecting portions (pivot portions) D and E, respectively, which change in the order of 1-2-3 in the figure. Further, the illustration of the upper link 8 which is not directly involved in the steering of the axle is omitted.

As described above, the present invention has been described with reference to the specific embodiments, but the present invention is not limited to this, and is attached to the present invention by a person skilled in the art. It should be noted that various changes and modifications can be made without departing from the scope of the utility model registration claim.

[0022]

[Effect of device]

 As described above, according to the vehicle rear axle support device of the present invention, since the oversteer characteristic is provided at the start of turning, the steering delay at the start of turning is reduced, and the understeer characteristic is provided at the time of turning, resulting in cornering force. It is possible to obtain a stable turning performance of the vehicle, which is a practical effect that can improve the maneuverability and stability of the vehicle.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a rear axle support device for a vehicle according to the present invention.

[Figure 2] Side view

[Figure 3] Rear view

FIG. 4 is a cross-sectional view showing a connecting structure between an upper link and a vehicle body of the above embodiment.

FIG. 5 is a plan view showing the structure of the lateral link according to the embodiment.

FIG. 6 is a sectional view thereof.

FIG. 7 is a plan view showing the turning direction of the vehicle.

FIG. 8 is a characteristic diagram showing steer characteristics.

FIG. 9 is a plan view showing a turning operation of the vehicle.

FIG. 10 is a plan view showing changes in the positions of the lateral link and the lower link.

[Figure 11] Rear view

[Figure 12] Left side view

[Figure 13] Right side view

FIG. 14 is a plan view showing an example of a conventional rear axle support device for a vehicle.

[Figure 15] Side view

[Explanation of symbols]

 7 Rear Axle 8 Upper Link 9 Vehicle Body 10 Rubber Bushing 16 Lateral Link 16b Rubber Bushing 16e Rubber Bushing 19 Support 20 Lower Link

Claims (1)

[Scope of utility model registration request] 1. An upper front side is supported by a vehicle body via an upper link, lower left and right lower portions are connected to a vehicle body by a lower link via supports, and a lateral link is provided above the lower link on the upper rear side. A rear axle is supported by the vehicle body through the rear link, and the lower link is positioned so that its rear side is located at the upper side and the plane shapes thereof are substantially V-shaped so that the vehicle body side mounting width is narrower than the rear axle side mounting width. While being formed so as to form an elastic bush at each of the rotational coupling portions of the upper link, the lower link and the lateral link, and at the rear axle side rotational coupling portion of the lateral link. A rear axle support device for a vehicle, wherein the inserted bush has a shape having a low elastic force in a lateral direction.