JP3136958B2 - Vehicle rear suspension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear suspension device for a vehicle in which a body support member such as a coil spring can be arranged on a lower arm.

[0002]

2. Related Art As a rear suspension device of this type, a double wishbone type suspension having a trailing arm, an upper arm and a lower arm is known. There is a type in which a shock absorber having a coil spring is disposed at an end portion, and a type in which a coil spring is separated from a shock absorber and the coil spring is disposed on a trailing arm. In this type of suspension, the trailing arm extends from the carrier of the wheel in the front-rear direction of the vehicle body.

In the latter suspension, the coil spring can be disposed below the vehicle body, so that a larger space in the vehicle compartment can be secured than in the former suspension. However, when the trailing arm moves up and down together with the vehicle body, the reaction force of the coil spring is increased. Is applied directly downward to the trailing arm. For this reason, the reaction force is converted via the trailing arm into a moment that causes the wheel to fall inward. Therefore, a compressive force acts on the upper arm of the suspension, and a tensile force acts on the lower arm. Therefore, it is necessary to reinforce the upper and lower arms.

[0004] In particular, the upper arm generally has a bent shape in general in order to avoid interference with the vehicle body, the drive shaft, and the like. For this reason, the effect of the additional compressive force on the upper arm must be avoided since the upper arm has reduced strength against compression.

[0005]

Therefore, it is conceivable to dispose a coil spring on the lower arm instead of the trailing arm. However, since the drive shaft and the upper arm are disposed above the lower arm, Arranging the coil spring on the lower arm becomes difficult.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it difficult for a reaction force from a vehicle body support member such as a coil spring to be converted into a compression force of an upper arm. It is another object of the present invention to provide a rear suspension device for a vehicle in which a vehicle body support member can be arranged and a toe change of a wheel can be led to linear characteristics.

[0007]

The above object is achieved by a vehicle rear suspension device according to the present invention. The device of claim 1 is capable of rotatably supporting a wheel at one end, and is capable of supporting a wheel from one end. A wheel support member extending forward of the vehicle body and having the other end pivotally supported by the vehicle body; one end rotatably connected to the wheel support member and the other end pivotally supported by the vehicle body; An upper arm extending to the vehicle body, a lower arm pivotally supported at one pivot point on the vehicle body side and connected to the wheel support member, and connecting between the vehicle body side and the lower arm to resilient the vehicle body in a vertical direction. And a vehicle body supporting member that supports the vehicle body. In the case of the device of claim 1, the lower arm is connected to one pivot point on the vehicle body side, a first pivot point located on one end side of the wheel support member on the wheel support member, and from the first pivot point. It has an A-shape which is pivotally connected at a second pivot point located forward in the front-rear direction of the vehicle body, and is provided between the first pivot point of the lower arm and the pivot point at the other end of the wheel support member. When considering a connecting line segment, the second pivot point is located near the line segment.

According to the rear suspension device of the first aspect, when the wheel support member and the A-shaped lower arm move up and down together with the vehicle body, the lower arm rotates around an imaginary axis connecting the first and second pivot points. Move up and down while moving. Thus, when the reaction force of the vehicle body support member is transmitted to the wheel support member from the lower arm, the rotation of the lower arm is transmitted to the vehicle wheel support member toward the reaction force of the vehicle body support member in a direction of a line segment as described above, and The transmission force acts on the wheel from one end of the wheel support member. As a result, the point of action of the reaction force is positioned closer to the wheel than the point of disposition of the vehicle body support member, and the above-mentioned moment acting on the wheel is greatly reduced, and the reaction force of the vehicle body support member is applied to the upper arm. It is difficult to convert to a compression force.

According to the second aspect of the present invention, the second pivot point of the lower arm is located on the aforementioned line segment. In this case, the virtual axis of the lower arm completely overlaps the line segment. The rotation of the lower arm about the virtual axis and the vertical movement of the wheel support member are smoothly guided. In the device according to the third aspect, when considering a plane formed by the pivot point on the vehicle body side of the lower arm and the first and second pivot points, the normal extending from the ground contact point of the wheel to this plane is as described above. Intersects the line segment or its extension, or
It passes near the line segment or the extension line. In this case, geometrically, the first pivot point of the lower arm is located at one end of the wheel supporting member, so that the horizontal distance between the point of application of the reaction force and the ground point of the wheel is substantially reduced. And the generation of the above-mentioned moment is suppressed.

According to a fourth aspect of the present invention, the second pivot point of the lower arm is elastically supported and includes an elastic support member having a rotation axis in substantially the same direction as the above-mentioned line segment. In this case, the manufacturing error of the wheel support member and the lower arm is elastically supported at the second pivot point, that is, absorbed by the elastic support member, and the above-described rotation of the lower arm is smoothly guided. Further, when the lower arm is rotated, the member for elastically supporting the second pivot point does not become stiff.

According to the fifth aspect of the present invention, the pivot point at the other end of the wheel support member is elastically supported, while the lower arm is located between the first and second pivot points on the wheel support member. There is also a pivotally and resiliently supported third pivot point, which is vertically offset from said line segment. The third pivot point of the lower arm restricts the rotation about the imaginary axis described above.
And the elastic support of the third pivot point allows the lower arm to rotate, and the restraint by the third pivot point elastically displaces the other end of the wheel support member. Such a displacement of the wheel support member also makes it possible to linearly change the toe angle of the wheel.

In the apparatus according to the sixth aspect, the pivot point at the other end of the wheel supporting member and the second pivot point of the lower arm are both elastically supported, while the second pivot point is vertically moved from the line segment. Is deviated in the direction. In this case, the second pivot point functions similarly to the third pivot point described above.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, one rear wheel RW of a vehicle is schematically shown, and the rear wheel RW is supported by a wheel carrier 2. Wheel carrier 2
The is rotatably supported axles (not shown) is attached by the knuckle 4, the axle is connected to a so-called drive shaft (not shown) via a universal joint, the axle by the rotation of the drive shaft, i.e. , The rear wheel RW is driven.

One end of a trailing arm 6 is integrally connected to the knuckle 4, and this one end constitutes a wheel-side support 7 for an upper and lower arm described later. Here, the wheel carrier 2, the knuckle 4, and the trailing arm 6 constitute a wheel supporting member for rotatably supporting the rear wheel RW. Wheel support members,
That is, the trailing arm 6 extends forward and toward the inside of the vehicle body as viewed in the front-rear direction of the vehicle, and a connecting ring 8 is integrally formed at the other end. An elastic bush 10 and a pivot pin 12 are incorporated in the connection ring 8, and the pivot pin 12 is connected to a bracket projecting from a suspension member (not shown) on the vehicle body side. Therefore, the other end of the trailing arm 6 is elastically supported on the vehicle body side.

The pivot pin 12 is inclined with a predetermined retreat angle with respect to the width direction of the vehicle, and the axis of the trailing arm 6 is inclined with a predetermined dihedral angle with respect to the horizontal plane. ing. In FIG. 1, the front of the vehicle is indicated by an arrow F. An upper arm 14 is disposed above the trailing arm 6, and the upper arm 14 has an I-shaped cross section and extends in the width direction of the vehicle body. One end of the upper arm 14 is connected to one end of the trailing arm 6, that is, the above-described wheel-side support 7 via a ball joint 16. A connecting ring 18 is formed integrally with the other end of the upper arm 14, and the connecting ring 18 is elastically supported by a suspension member on the vehicle body side similarly to the connecting ring 8 of the trailing arm 6. As is clear from FIG.
4 generally has a bent shape to avoid interference with the vehicle body and the drive shaft.

A lower arm 20 is arranged below the trailing arm 6, and this lower arm 20 also extends in the width direction of the vehicle body. The lower arm 20 has an A-shape having three ends with the vehicle body as a vertex, and a connecting ring 22 is integrally formed at the vertex end. The connecting ring 22 is elastically supported by a suspension member on the vehicle body side.

The other ends of the lower arm 20 are also integrally formed with connecting rings 24 and 26, respectively. The connecting rings 24 and 26 are resiliently pivotally attached to the lower side of the trailing arm 6. The pivoting of the connecting rings 22, 24, 26 to the vehicle body side and the trailing arm 6 is performed in the same manner, and FIG. 3 specifically shows the pivoting structure between the coupling ring 26 and the trailing arm 6. Have been. That is, the connecting ring 26 incorporates an elastic bush 28 and a pivot pin 30, and both ends of the pivot pin 30 are connected to a pair of brackets 32 protruding from the lower surface of the trailing arm 6.

Referring again to FIG. 1, the lower arm 20
Is connected to the wheel support 7 of the trailing arm 6 and is positioned directly below the knuckle 4. On the other hand, the connection ring 26 of the lower arm 20 is positioned away from the connection ring 24 in front of the vehicle body.
In the lower arm 20, the connecting rings 22, 24
Are parallel to each other.

The positions where the connecting rings 24 and 26 of the lower arm 20 are connected to the trailing arm 6, respectively, that is, the pivot points of the lower arm 20 are A and B, respectively, and the connection of the trailing arm 6 to the vehicle body side. When the pivot point to which the ring 8 is connected is C, and a line segment connecting the pivot point C and the pivot point A is considered, the pivot point B is located on this line segment. Connecting ring 2 at pivot point B
The axis 6 is arranged on the line segment.

[0020] Referring to FIGS. 4 and 5, the line segments described above are indicated by reference numeral L, also, the axis of the pivot point B in the lower arm 20 is shown in FIG. 3 M. Further, assuming that a pivot point at which the coupling ring 22 of the lower arm 20 is coupled on the vehicle body side is D, a triangular plane P formed by the pivot point D and the pivot points A and B as shown in FIG. When the normal H to the plane P is extended from the ground contact point of the rear wheel RW, the normal H intersects with the above-described line L or its extension, or the vicinity of the line L or the extension. Has passed.

As shown in FIG.
A coil spring 34 serving as a vehicle body support member is disposed between the vehicle and the vehicle body on the trailing arm 6 side. The coil spring 34 elastically supports the vehicle body in the vertical direction. FIG. 2 also schematically shows a shock absorber 36 connecting between the vehicle body side and the wheel side support 7 of the trailing arm 6. In addition,
As is clear from FIGS. 1 and 2, the lower arm 20 is formed with two triangular openings 38 to reduce the weight.

According to the above-described rear suspension device, when the vehicle body moves up and down relatively with respect to the rear wheel RW, the trailing arm 6, the upper arm 14 and the lower arm 20 move up and down with the expansion and contraction of the coil spring 34 together with the vehicle body. Rotate in the direction. Here, regarding the movement of the trailing arm 6 and the lower arm 20, when the trailing arm 6 is considered as a center, the so-called link interference occurs because the pivot point B of the lower arm 20 is located on the line L described above. 7, the lower arm 20 is connected to the virtual axis M connecting the pivot points A and B, as indicated by the arrow X in FIG.
Will rotate around. Therefore, the lower arm 20
The reaction force UF of the upper coil spring 34 is lower arm 2
The rotation of 0 causes the light to be transmitted to the trailing arm 6 in the direction of the line segment L. Therefore, the transmission force transmitted to the trailing arm 6 due to the reaction force UF has an action point on the line segment L of the trailing arm 6,
Since the distance Y between the line segment L and the normal H extending from the contact point of the rear wheel RW is short, the moment defined by the transmission force and the distance Y, that is, the rear wheel RW is tilted inward. No moment is substantially generated. As a result, the moment is not converted into a compressive force on the upper arm 14, and the upper arm 14 does not need to be reinforced.

Since the pivot point B of the lower arm 20 is elastically supported as described above, an imaginary axis line between the pivot points A and B of the lower arm 20 due to a manufacturing error of the lower arm 20 and the trailing arm 6 and the like. Even if M does not completely overlap the line segment L, the above-described rotation of the lower arm 20 can be smoothly ensured by the elastic displacement of the pivot point B.

Further, since the pivot point B, that is, the elastic bush 28 (see FIG. 3) is arranged concentrically with respect to the line segment L, when the lower arm 20 rotates, the elastic bush 28 The stiffness does not occur, and the hysteresis of the elastic return force due to the stiffness can be prevented. next,
Referring to FIG. 8, a modification of the lower arm 20 is shown. In this modification, the lower arm 20 has pivot points A and B
And a pivot point E pivotally connected to the trailing arm 6, which pivot point E is indicated by a solid line and a two-dot chain line in FIG. Pivot points A and B
It is positioned so as to be deviated downward or upward with respect to the virtual axis M connecting between them. The structure of the pivot point E is the same as the structure at the pivot point B, so that the lower arm 20 is also elastically supported by the trailing arm 6 at the pivot point E.

When the pivot point E is added to the lower arm 20, the pivot point E restricts the rotation of the lower arm 20 to cause link interference. In this case, the pivot point B , E, any of the elastic bushes is bent, and the rotation of the lower arm 20 is allowed, so that the above-described function can be secured. Further, since the pivot point E is displaced downward or upward, the link interference given to the rotation of the lower arm 20 exerts a force on the trailing arm 6 in the vehicle body width direction of the line segment L. Will be added. Therefore, due to the elastic deformation of the elastic bush 10 at the other end of the trailing arm 6, its pivot point C, that is, the trailing arm 6 is forcibly displaced in the direction indicated by the arrow Z in FIG.
As a result, it is possible to linearly change the toe angle of the rear wheel RW, and it is easy to set the toe angle.

FIG. 9 shows a lower arm 20 according to still another modification.
Is replaced by a pivot point B ′ whose pivot point B is deviated downward or upward from the line segment L like the pivot point E described above. Also in this case, since the pivot point B ′ restricts the rotation of the lower arm 20 in the same manner as the pivot point E,
Functions similar to those of the suspension device of FIG. 8 can be exhibited.

In the embodiment described above, the axes of the connecting rings 22 and 24 are set parallel to each other with respect to the lower arm 20, but the axis of the connecting ring 24 may be set in the same direction as the axis of the connecting ring 26. Also, the openings 38 are not limited to triangles, but may be of any shape, and the number thereof is not limited to two.

[0028]

As described above, according to the rear suspension device of the first aspect of the present invention, the lower arm
As a mold, since it is rotatable by being connected to the wheel support member at two pivot points, even when the vehicle body support member is disposed on the lower arm, the reaction force of this vehicle body support member is expressed by the line segment. To the wheel support member. As a result, the moment of tilting the wheel inward is reduced, and the reaction force of the vehicle body support member is less likely to be converted into a compressive force applied to the upper arm.

According to the device of the second aspect, the rotation of the lower arm can be smoothly guided, and according to the device of the third aspect,
The generation of the moment can be substantially prevented. According to the device of the fourth and fifth aspects, since the rotation of the lower arm is restrained while allowing the rotation, the forced elastic displacement can be given to the pivot point at the other end of the wheel support member. Therefore, it is possible to generate a linear toe change on the wheel.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a rear suspension device according to one embodiment.

FIG. 2 is a schematic rear view of the apparatus of FIG. 1 as viewed from the rear of the vehicle.

FIG. 3 is a sectional view specifically showing the structure of one pivot point in the lower arm.

FIG. 4 is a configuration diagram of an apparatus corresponding to FIG.

FIG. 5 is a configuration diagram of an apparatus corresponding to FIG. 2;

FIG. 6 is a diagram for explaining a geometrical arrangement of a lower arm.

FIG. 7 is a schematic configuration diagram of an apparatus for explaining an operation of one embodiment.

FIG. 8 is a schematic configuration diagram showing a modification of the device.

FIG. 9 is a schematic configuration diagram showing another modification of the device.

[Explanation of symbols]

 Reference Signs List 6 trailing arm 7 wheel side support 10 elastic bush 14 upper arm 20 lower arm A pivot point B pivot point C pivot point (trailing arm) D pivot point (lower arm) E pivot point (lower arm) B 'pivot point ( Lower arm) 34 Coil spring (body support member) RW Rear wheel

Claims (6)

(57) [Claims] A wheel support member rotatably supported at one end, extending forward from the one end to the front of the vehicle body, and the other end pivotally supported by the vehicle body; One end is rotatably connected and the other end is pivotally supported on the vehicle body side, and extends substantially in the width direction of the vehicle body.
A lower arm that is pivotally supported at one pivot point on the vehicle body side and is connected to the wheel support member; and connects the vehicle body side and the lower arm with each other to vertically move the vehicle body. A lower body, the lower arm having one pivot point on the vehicle body side, and a first pivot attached to the wheel support member at one end of the wheel support member. A point and a second pivot point located forward of the first pivot point in the longitudinal direction of the vehicle body with respect to the first pivot point. A rear suspension device for a vehicle, wherein the second pivot point is disposed near a line segment connecting a pivot point at the other end of the member. 2. The vehicle rear suspension apparatus according to claim 1, wherein the second pivot point of the lower arm is located on the line segment. 3. A normal extending from a ground contact point of the wheel with respect to a plane formed by the vehicle body-side pivot point of the lower arm and the first and second pivot points, The vehicle rear suspension device according to claim 2, wherein the vehicle passes near a line segment or an extension line thereof. 4. The apparatus according to claim 2, wherein the second pivot point of the lower arm is elastically supported, and includes an elastic support member having a rotation axis substantially in the same direction as the line segment.
The vehicle rear suspension device according to claim 1. 5. A pivot point at the other end of the wheel support member is elastically supported, while the lower arm is pivotally attached to the wheel support member between the first and second pivot points. The rear of a vehicle according to claim 4, further comprising a third pivot point that is formed and elastically supported, and the third pivot point is vertically displaced from the line segment. Suspension device. 6. A pivot point at the other end of the wheel support member and the second pivot point of the lower arm are both elastically supported, while the second pivot point is vertically moved from the line segment. The vehicle rear suspension device according to claim 1, wherein the vehicle is displaced.