JPH0728961Y2 - Vehicle rear suspension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an improvement in the structure of a rear suspension device of a vehicle mounted on a vehicle such as an automobile.

(Prior Art) Generally, for example, a rear suspension device of a vehicle such as an automobile is known as shown in Japanese Patent Publication No. 60-42041. This is a longitudinal stay (front link arm) having one end connected to the vehicle body side and the other end attached to the wheel side, and one end side rotatably attached to the vehicle body at a position rearward of the longitudinal stay. , Lateral stay with the other end attached to the wheel side (rear link arm)
Respectively, the lateral stays are formed by elastic members such as leaf springs, and a swivel support is disposed between the longitudinal stays and the vehicle body side. One end side of the swivel support body is rotated to the vehicle body side. It is movably mounted and hinged between the other end of the swivel bearing and the longitudinal stay via a pin that forms a vertical swivel axis. In this case, a cylindrical sleeve is formed on the longitudinal stay, and a bush formed by an elastic body is arranged between the sleeve and the swivel support. further,
The bush has a notch extending horizontally.

Then, when a braking force is applied to the rear wheels, a reaction force in the direction opposite to the traveling direction is applied to the longitudinal stays, and this reaction force causes the swivel bearing body to face inward about the pin that forms the swivel axis. The rear wheel is swung in the toe-in direction via the longitudinal stay in accordance with the turning motion of the swivel bearing, thereby compensating for the toe-out direction deviation acting on the rear wheel by the braking force. There is.
In this case, the toe change of the rear wheel is performed according to the amount of bending of the lateral stay formed by the leaf spring, and the lateral stay is in the normal position when the leaf spring is not deformed. .

(Problems to be Solved by the Invention) Generally, when the vehicle body is turning (when cornering), an external force (lateral force) is applied to the rear wheel on the outer wheel side from the lateral direction. Need to receive. However, in the above-mentioned conventional structure, since the lateral stay is formed by an elastic member such as a leaf spring, the plate thickness of the leaf spring cannot be reduced due to the buckling strength of the lateral stay. was there. Therefore, since the plate spring of the lateral stay tends to be relatively thick, there is a problem that a relatively large force is required when elastically deforming the plate spring of the lateral stay. If a large force is required for elastic deformation of the leaf spring of the lateral stay, the leaf spring of the lateral stay is caused by the lateral force when the lateral force acts on the rear wheel on the outer wheel side during turning of the vehicle body. Since it becomes difficult to elastically deform the vehicle, it is difficult to obtain the toe-in effect on the rear wheel on the outer wheel side, and there is a problem that the vehicle tends to oversteer.

In addition, since the lateral force acting on the rear wheel on the outer wheel side is received by the lateral stay formed by the leaf spring during the turning operation of the vehicle body, it is necessary to dispose the lateral stay in the vehicle width direction. Therefore, there is a problem that the entire rear suspension device becomes large.

Further, the toe change of the rear wheel is performed according to the amount of bending of the lateral stay formed by the leaf spring, but this lateral stay is in the normal position when the leaf spring is not deformed. Therefore, it is impossible to extend the length of the leaf spring forming the lateral stay longer than the normal position, as in the case of moving the rear wheel to the toe-out position. Therefore, it is impossible to cause the rear wheels on the inner wheel side to perform the toe-out operation during the turning operation of the vehicle body, and it is difficult to improve the turning performance.

This invention was made with attention to the above-mentioned problems, and even if a lateral force acts on the outer wheel side rear wheel during the turning operation of the vehicle body, the toe-in effect can be obtained on the outer wheel side rear wheel,
An object of the present invention is to provide a rear suspension device for a vehicle, which can improve the turning performance and safety by generating an understeer tendency in the vehicle and can improve the maintainability.

[Construction of the Invention] (Means and Actions for Solving Problems) That is, the invention is a trailing arm which is arranged substantially in the front-rear direction of the vehicle and which rotatably supports rear wheels at the rear part, and an outer side which is arranged substantially in the vehicle width direction. A pair of upper and lower lateral arms whose parts are pivotally attached to the rear part of the trailing arm and whose inner ends are pivotally attached to the vehicle body side; and the trailing arm is a rod whose front end part is pivotally attached to the vehicle body side. It is divided into an assist link formed in a shape and a trailing link having a cylindrical portion having a rear end connected to the rear wheel side and a rear end of the assist link loosely fitted to the front end. The link is rotatably connected to each other about a rotary shaft whose axial center direction is oriented in a substantially vertical direction,
A bush made of an elastic material is interposed between the trailing link and the assist link, and the front end portion of the assist link is arranged on the inner side in the vehicle width direction with respect to the rear end portion, and in the horizontal plane of the vehicle body. An extension line passing through the center of the pivoting portion at both ends of the assist link and an extension line passing through the centers of the pivoting portions at both ends of the lateral arm inside and outside of the lateral arm are crossed behind the center of the rear wheel and outward in the vehicle width direction. In the rear suspension device for a vehicle in which the arms are arranged in the rear end portion of the trailing link, the assist link has the rear end portion to which the bush is fitted, and the rear end portion to which the bush is fitted. It is configured to be press-fitted into a cylindrical body that is fitted into the portion and is connected to the trailing link by the rotating shaft.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.
1 and 2 show a schematic configuration of a main part of a rear suspension device of a vehicle such as an automobile. 1 is a tire of a rear wheel, 2 is a propeller shaft on a vehicle body side, 3 is a body frame, 4 is a It is a suspension cross member.
The suspension cross member 4 is arranged along the vehicle width direction, and is mounted in a erected state between a pair of body frames 3 arranged on the left and right of the vehicle body. further,
The suspension cross member 4 is bent and formed with its central portion side curved toward the rear side of the vehicle body. In this case, the suspension cross member 4 is attached to the body frame 3 side via a cross member bush 5 formed of an elastic body.

6 is a trailing arm for supporting the rear wheels, 7a, 7b
Is a pair of upper and lower lateral arms (upper link 7a and lower link 7b). The trailing arm 6 is divided into an assist link (vehicle body side arm) 8 pivotally attached to the vehicle body side and a trailing link (wheel side arm) 9 connected to the rear wheel side. In this case, the assist link 8 is arranged inside the trailing link 9 in the vehicle width direction. Further, a cylindrical portion 10 is formed at the front end of the trailing link 9 as shown in FIG. 3, and the tip end side of the rod-shaped assist link 8 is inserted into the cylindrical portion 10. The base end side of the assist link 8 is elastically pivoted to the suspension cross member 4 via a bush formed of an elastic body. In addition, the tip end side of these assist links 8 and the trailing links 9
A rotating shaft 11 is attached to the cylindrical portion 10 in a penetrating state. The axis of rotation of the rotating shaft 11 is arranged substantially in the vertical direction, and the rotating shaft 11 rotates between the tip of the assist link 8 and the cylindrical portion 10 of the trailing link 9. It is movably connected. Further, a bush 12 formed of an elastic body is interposed between the cylindrical portion 10 of the trailing link 9 and the tip end side of the assist link 8 by means described below.

That is, FIGS. 3 to 5 show a connecting structure of the assist link 8 and the trailing link 9, wherein 80 is a shaft portion of the assist link 8, and a shaft portion 80 has a ball portion.
81 is provided. The outer circumferences of the shaft portion 80 and the ball portion 81 of the assist link 8 are covered with the bush 12, and a through hole 82 is formed in the ball portion 81 at right angles to the axis center of the assist link 8. Further, a collar 83 penetrating the bush 12 is inserted into the through hole 82 to form an inserting portion into which the rotating shaft 11 is inserted. Then, the bush 12 that covers the shaft portion 80 and the ball portion 81 of the assist link 8
Is press-fitted into the cylinder 84, and the collar
A through hole 85 facing the end of 83 is provided. The assist link assembly 86 configured as described above is inserted into the cylindrical portion 10 of the trailing link 9, and in this state,
Rotating shaft 11 consisting of bolts and nuts via washers 87, 87
The assist link 8 and the trailing link 9 are connected by inserting the above into the collar 83. That is, the trailing arm 6 is configured by connecting the preassembled assist link assembly 86 to the trailing link 9 by the rotating shaft 11.

A substantially cylindrical axle housing 13 and a hub carrier 14 fitted to the outer peripheral surface of the axle housing 13 are integrally fixed to the rear end of the trailing link 9 by means such as welding. An upper support portion 15 that pivotally supports the upper link 7a of the lateral arm is formed on the upper portion of the hub carrier 14, and a lower support portion 16 that pivotally supports the lower link 7b of the lateral arm is formed on the lower portion of the hub carrier 14. ing.

Further, the outer end of the upper link 7a of the lateral arm is ball-jointed to the upper support portion 15 of the hub carrier 14.
The inner end portion of the suspension cross member 4 on the vehicle body side is elastically pivoted via a bush formed of an elastic body at a portion near the rearward projecting portion 4a of the curved portion. Has been done. Similarly to the upper link 7a, the lower link 7b of the lateral arm has an outer end pivotally attached to the lower support portion 16 of the hub carrier 14 via a ball joint 16a, and an inner end portion of the suspension cross on the vehicle body side. The member 4 is elastically pivotally attached to the vicinity of the rearward projecting portion 4a at the tip of the curved portion of the member 4 via a bush formed of an elastic body. In this case, the upper link 7a and the lower link of the lateral arm
The connecting portion between 7b and the suspension cross member 4 on the vehicle body side is disposed on the vehicle body front side with respect to the connecting portion between the upper link 7a and the lower link 7b of the lateral arm and the trailing link 9 side. The assist link 8, trailing link 9 and lateral arm (upper link 7a and trailing link 9) of the trailing arm 6 constitute a four-section link as shown in FIGS. 6 and 7. There is. Further, the connecting portion between the upper link 7a of the lateral arm and the trailing link 9 side is disposed on the vehicle body front side with respect to the connecting portion between the lower link 7b of the lateral arm and the trailing link 9 side, and in the vehicle width direction. It is located inside. Further, a shock absorber bracket is formed at the rear end of the trailing link 9, and the lower end of the strut type shock absorber 17 is connected to the shock absorber bracket.

On the other hand, a differential device 18 is attached to the rear protruding portion 4a at the tip of the curved portion of the suspension cross member 4. A rear end portion of the differential device 18 is supported by a differential support member 19 mounted between the left and right body frames 3 and 3 in an installed state. Further, the diff support member 19 is elastically connected to the body frame 3 side via a diff support member bush 20 formed of an elastic body. Reference numeral 21 is a drive shaft, and 22 is a rear wheel spindle.

Therefore, in the above-mentioned structure, the trailing arm 6 has the assist link 8, the trailing link 9 and the lateral arm (upper link 7a and trailing link 9) as shown in FIGS. 6 and 7. The rear wheel spindle 22 is caused by the relative rotation between the trailing link 9 and the assist link 8 about the rotation shaft 11 connecting the assist link 8 and the trailing link 9 of the arm 6. Since I constructed the link of Section 4 to move the position of to change the toe of the rear wheel,
For example, when a rearward force is applied to the vehicle body such as during braking operation, the trailing link 9 is applied by the rearward force.
And the assist link 8 are caused to rotate relative to each other about the rotating shaft 11, and the link is virtually moved from the normal position shown by the solid line in FIG. The toe change of the rear wheels can be performed by deforming to the toe-in position shown by the line.

Further, the connecting portion between the upper link 7a and the lower link 7b of the lateral arm and the suspension cross member 4 on the vehicle body side should be closer to the vehicle body than the connecting portion between the upper link 7a and the lower link 7b of the lateral arm and the trailing link 9 side. Since it is arranged on the front side, the center line 01 of the assist link 8 of the trailing arm 6 and the center line of the lateral arm (center line 03 of the upper link 7a and center line of the lower link 7b)
The instantaneous center P of the suspension arm formed by the intersection with the center line (between 04 and 02) is set to the rear side of the axle. Therefore, for example, when a lateral force acts on the rear wheel on the outer wheel side from the outside as indicated by an arrow F in FIG. 1 during the turning operation of the vehicle body, the trailing link 9 is applied by this lateral force.
And the assist link 8 are caused to rotate relative to each other about the rotary shaft 11, and the link is deformed in accordance with this rotary motion to cause a toe-in effect on the rear wheel on the outer wheel side and a rear wheel on the inner wheel side. When a lateral force is applied to the wheels from the inside, a toe-out effect can be applied to the rear wheels on the inner wheel side, so that an understeer tendency can be reliably generated in the vehicle during the turning operation of the vehicle body. Therefore, it is possible to improve the turning performance and safety of the vehicle during the turning operation of the vehicle body.

Further, the connecting portion between the upper link 7a of the lateral arm and the trailing link 9 side is arranged on the vehicle body front side and inward in the vehicle width direction with respect to the connecting portion between the lower link 7b of the lateral arm and the trailing link 9 side. Therefore, as shown in FIG. 8, a virtual kingpin shaft that supports wheels (a connecting portion between the upper link 7a of the lateral arm and the trailing link 9 side, a connecting portion between the lower link 7b of the lateral arm and the trailing link 9 side). It is possible to hold a shaft 23 oriented in a direction along a line connecting the line and the line 23 in a state of being inclined forward. Therefore, for example, when a forward force is applied to the vehicle body during normal traveling, an inward moment can be generated around the virtual kingpin shaft 23, and a toe-in effect can be given to the rear wheels.

Further, the connecting portion between the upper link 7a and the lower link 7b of the lateral arm and the suspension cross member 4 on the vehicle body side should be closer to the vehicle body than the connecting portion between the upper link 7a and the lower link 7b of the lateral arm and the trailing link 9 side. Placed on the front side, lateral link upper link
Since the 7a and the lower link 7b are arranged obliquely with respect to the vehicle width direction, it is possible to reduce the size of the entire rear suspension device as compared with the case where these are arranged in the vehicle width direction.

Further, the base end portion side of the assist link 8 of the trailing arm 6 is elastically pivotally attached to the suspension cross member 4 via a bush formed of an elastic body, and the upper link 7a and the lower link 7b of the lateral arm are also attached.
Since the inner end of the suspension cross member 4 is elastically pivotally attached to a portion of the suspension cross member 4 in the vicinity of the rearward projecting portion 4a at the tip of the curved portion, the suspension cross member 4 is attached to the body frame 3 side. The rear suspension device can be mounted on the suspension cross member 4 before mounting on. Therefore, the workability of assembling the vehicle body can be improved. Further, since the central portion side of the suspension cross member 4 is curved to the rear side of the vehicle body, the workability is improved when the differential device 18 is mounted on the rear protrusion 4a at the tip of the curved portion of the suspension cross member 4. It can also be planned.

[Advantage of the Invention] According to this invention, when a rearward force is applied to the rear wheel during braking, a rotational moment force around the instantaneous center outside the rear wheel center acts to deform the trailing link and the assist link. As a result, when the rear wheels toe-in and the lateral force is applied to the rear wheels on the outer wheel side during the turning operation of the vehicle body, the turning outer wheel can be toe-in and the inner turning wheel can be toe-out. Can be achieved. Further, both the improvement of the turning performance and the improvement of the braking stability as a toe-in during braking can be achieved at the same time. That is, there is an effect that the rear wheels toe-in act extremely effectively during braking and turning, and the steering stability of the vehicle is improved. In addition, the bush covering the assist link is press-fitted into the cylindrical body to form the assist link assembly, and the assist link assembly is inserted into the trailing link, so that the assembly can be assembled and the assembling workability and the maintainability can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic structure of a main part of a vehicle rear suspension device showing an embodiment of the present invention, FIG. 2 is a perspective view of the same, and FIGS. 3 to 5 are assist links and trailing links. FIG. 3 and FIG. 4 are perspective views, FIG. 5 is a cross-sectional view, FIG. 6 is a perspective view showing a linking state of the links, and FIG. 7 is a plan view of the same. FIG. 8 is a side view of the same. 6 ... Trailing arm, 8 ... Assist link, 9
...... Trailing link, 11 …… Rotary axis, 12 …… Bush, 84 …… Cylinder body.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Shoji Yamamoto, Shoji Yamamoto, No. 1 Nakashinri, Hashime-cho, Okazaki-shi, Aichi Inside Passenger Car Technology Center, Mitsubishi Motors Corporation (72) Hiroaki Yoshida, Hashime-cho, Okazaki, Aichi Shinriki No. 1 in Mitsubishi Motors Corporation Passenger Car Technology Center (72) Inventor Masayoshi Nishimori Nakamiri No. 1 in Hashime-cho, Okazaki City, Aichi Prefecture Mitsubishi Motors Co., Ltd. Passenger Car Technology Center (72) Inventor Shinichi Eto Aichi No. 1 Nakashiniri, Hashime-cho, Okazaki-shi, Japan (56) References in the Passenger Vehicle Technology Center, Mitsubishi Motors Corporation (57) Reference: JP-A-57-51508 (JP, A) Actually published: JP-A-57-163404 (JP, U) 60-42041 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A trailing arm which is arranged substantially in the front-rear direction of a vehicle and rotatably supports a rear wheel at a rear portion, and an outer portion which is arranged substantially in the vehicle width direction and whose outer portion is pivotally attached to the rear portion of the trailing arm and whose inner end portion is formed. Includes a pair of upper and lower lateral arms pivotally attached to the vehicle body side, and the trailing arm is connected to an assist link formed in a rod shape with its front end portion pivotally attached to the vehicle body side and its rear end connected to the rear wheel side. The trailing link is divided into a trailing link having a cylindrical portion in which a rear end portion of the assist link is loosely fitted to the front end, and the trailing link and the assist link are arranged with their axial center directions oriented in a substantially vertical direction. A bush made of an elastic material is interposed between the trailing link and the assist link, and the front end of the assist link is connected to each other so as to be rotatable about a rotary shaft. Is arranged on the inner side in the vehicle width direction with respect to this rear end portion, and in the vehicle body horizontal plane, an extension line passing through the center of the pivot portion at both ends of the assist link and an extension line passing through the center of the pivot portion at both ends of the lateral arm. However, in a rear suspension device for a vehicle in which the arms are arranged so as to intersect with the rear of the rear wheel center and outward in the vehicle width direction, the assist link may have the bush fitted at its rear end. The rear end portion, to which the bush is fitted, is fitted into the cylindrical portion of the trailing link and is press-fitted into a tubular body connected to the trailing link by the rotating shaft. Rear suspension system for vehicles.