JPH0976715A - Rear suspension structure - Google Patents

Abstract

[PROBLEMS] To provide a rear suspension structure that uses a leaf spring as a spring element of a suspension and can widen a space in a vehicle compartment and reduce the number of parts. SOLUTION: A rear suspension 1 includes a pair of leaf springs 6 and 7 and a pair of rods 8 and 9 to form rear left and right wheels 2.
Support 3 independently. The leaf springs 6 and 7 function as arms that support the spring elements and the wheels 2 and 3. The pair of leaf springs 6 and 7 and the pair of rods 8 and 9 constrain the degrees of freedom of the left and right wheels 2 and 3 in each of the six directions to establish a suspension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear suspension structure in which left and right rear wheels are independently supported by leaf spring members.

[0002]

2. Description of the Related Art Independent suspension suspensions, in which the left and right axles move independently of each other, are used for the front wheels of passenger cars because of their superior riding comfort and maneuverability compared to suspensions for fixed axles. Has also been adopted.

[0003]

However, in the independent suspension suspension, a coil spring having a large diameter is concentrically arranged outside the shock absorber as a spring element of the suspension arm to elastically support the wheel support member. Therefore, a considerable amount of space is required for.
In the case of the front wheels, it can be arranged in the engine room, but when it is adopted as the rear wheels, it will largely project into the vehicle compartment or the trunk, and the space will be greatly divided and narrowed. In particular, in a wagon vehicle and the like, not only dead space is likely to occur, but also there is a problem such as interference when loading and unloading luggage. In addition, the number of parts is large due to the structure, and it is expensive.

The present invention has been made in view of the above points, and uses a leaf spring as a spring element of a suspension arm to allow a large space in a vehicle compartment and reduce the number of parts. It is intended to provide a suspension structure.

[0005]

In order to achieve the above object, according to the present invention, in claim 1, a pair of wheel supporting members for rotatably supporting a wheel and one ends thereof are coupled to a vehicle body side, A pair of wide leaf spring members each having the other end connected to the respective wheel support members on the opposite side across the center of the vehicle body and intersecting each other at the vehicle center in a plan view of the vehicle body; And a pair of rod members arranged so as to cross each other at substantially the vehicle center, the other end being swingably supported by the wheel supporting members on the opposite side across the center of the vehicle body, At least one point of the attachment portion of the rod member is elastically supported.

According to a second aspect, the pair of leaf spring members are
Either or both of them are bent at the intersection of the vehicle center and are vertically offset. Claim 3
Then, the pair of rod members has a structure in which one or both of the rod members are bent and offset at the intersection of the vehicle center. According to a fourth aspect of the present invention, the pair of leaf spring members have a structure in which a first elastic member is interposed at an intersection of the vehicle center so as to abut both leaf spring members.

According to a fifth aspect of the present invention, a first elastic member is interposed between the upper leaf spring member and the lower leaf spring member at the intersection of the pair of leaf spring members, and is attached to the upper leaf spring member. A second connecting member extending below the lower leaf spring member;
The elastic member is provided, and the lower plate spring member is sandwiched by the upper plate spring member and the connecting member via both elastic members.

According to a sixth aspect of the present invention, the leaf spring has a structure in which the plate thickness gradually changes along the longitudinal direction. The rear suspension independently supports the left and right rear wheels by a pair of leaf springs and a pair of rods. The leaf spring functions as an arm that supports the spring element and the wheels.
The pair of leaf springs and the pair of rods support the left and right wheels by constraining the degrees of freedom in each of the six directions. The pair of leaf springs and the pair of rods are offset at the intersections to prevent interference, and the left and right turning characteristics are matched in a symmetrical layout. In addition, the pair of leaf springs has a stabilizer effect due to the elastic member interposed at the intersecting portion so as to come into contact with the both leaf spring members. Furthermore, the camber change can be adjusted by changing the plate thickness of the plate spring along the longitudinal direction to change the spring constant.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an outline of a rear suspension structure of the present invention, and FIG. 2 is a plan view of FIG. 1 and 2, the rear suspension 1 includes wheel support members 4 and 5 that respectively support left and right rear wheels 2 and 3 (hereinafter referred to as "wheels 2 and 3"), and these wheel support members 4 and 5. It is composed of a pair of wide and long leaf spring members 6 and 7 which independently support the above, a pair of long rod members 8 and 9, and shock absorbers 10 and 11.

The leaf springs 6 and 7 are arranged in front of the rear wheels 2 and 3 in the front-rear direction and at the vehicle center O in a plan view so that the flat springs, that is, the directions in which the springs act are directed vertically. Has been done. And one leaf spring member 6
Has one end 6a fixed to the left side member 12, and the other end 6b extending obliquely rearward across the vehicle center O and fixed to the trailing arm 5a of the right wheel support member 5. Similarly, one end 7a of the other leaf spring 7 is fixed to the right side member 13 and the other end 7b thereof is at the vehicle center O.
The wheel support member 4 on the left side extending diagonally rearward across the vehicle.
Is fixed to the trailing arm 4a. The leaf springs 6 and 7 and the side members 12 and 13 and the trailing arms 4a and 5a of the wheel supporting members 4 and 5 may be fixed to each other by interposing elastic members such as rubber. .

The leaf springs 6 and 7 intersect at intersecting portions 6c and 7
c is bent and offset in a direction (vertical direction) away from each other so that they do not interfere with each other. An elastic member 14 is interposed between the intersections 6c and 7c facing each other. This elastic member 14
The upper and lower surfaces are adhered to the opposing inner surfaces of the intersections 6c and 7c, respectively.

It should be noted that the leaf springs 6 and 7 do not necessarily need to be bent and offset at both intersections 6c and 7c.
Alternatively, for example, only the intersecting portion 6c of the leaf spring 6 may be bent upward. In this case, as shown in FIG. 3, the elastic member 15 is interposed between the intersecting portions 6c and 7c, and the bracket (connecting member) 17 is attached to the lower side of the intersecting portion 7c of the leaf spring 7 via the elastic member 16. It is preferable that both ends are fixed to both sides of the intersecting portion 6c of the leaf spring 6, and the leaf spring 7 is sandwiched between the leaf spring 6 and the bracket 17.
However, the intersections 6c, 7c of both leaf springs 6, 7
It is preferable to bend and offset the same in the same manner so that the layout becomes symmetrical and the characteristics of the leaf springs 6 and 7 (left and right turning characteristics) are matched.

The pair of rods 8 and 9 are lateral rods, which are arranged between the wheel supporting members 4 and 5 and the vehicle body side in a vertically and obliquely upward and downward direction and intersect each other at the vehicle center O. There is. And one rod 8 is
One end 8a is rotatably connected to an arm 4b provided above the left wheel support member 4, and the other end 8b is connected to the vehicle center O.
It extends diagonally upward to the opposite side across the vehicle and is rotatably connected to the vehicle body side via an elastic member (bush). One end 9a of the other rod 9 is rotatably connected to an arm 5b provided on the upper side of the wheel support member 5 on the right side, and the other end 9 is
b extends diagonally upward to the opposite side across the vehicle center O, and is rotatably connected to the vehicle body side via an elastic member (bush). Then, in these rods 8 and 9, the intersecting portions 8c and 9c intersect with each other in a direction in which they are separated from each other (front-rear direction).
It is bent and offset so that it does not interfere with each other when it is moved up and down.

In the rods 8 and 9, it is not always necessary to bend and intersect both of the intersecting portions 8c and 9c, and it is also possible to bend and offset the intersecting portion of either one of the rods. However, it is preferable to bend and offset both rods 8 and 9 in the same manner because the layout becomes symmetrical and the characteristics of the rods 8 and 9 (left and right turning characteristics) can be matched. .

Further, the shock absorbers 10 and 11 are
They are respectively interposed between the wheel support members 4 and 5 and the vehicle body side. The leaf spring 6 and the rod 9 support the right wheel support member 5, and the leaf spring 7 and the rod 8 support the left wheel support member 4. The leaf springs 6 and 7 have both a spring function and an arm function for supporting the wheel supporting members 4 and 5. In this way, the independent suspension type rear suspension 1 using the leaf springs 6 and 7 is configured.

The operation will be described below. On wheels 2 and 3,
Forces in six directions act when the vehicle is running. That is, the forces acting in the front-rear direction (X-axis direction), the left-right (lateral) direction (Y-axis direction), and the vertical direction (Z-axis direction) of the vehicle, and the three-direction forces, and the X, Y, and Z-axis rotations A total of 6 directional forces including 3 directional forces acting on the wheels 2 and 3 are applied to the wheels. For convenience of description, a case where the forces acting on the right wheel 3 in the above six directions are supported will be described below.

The forward and backward movement of the wheel 3 is supported by the tension of the leaf spring 6, and the upward and downward movement is supported by the spring force (flexing force) of the leaf spring 6 bending up and down. At this time, the shock absorber 11 suppresses the rebound of the wheel 3 and accelerates the damping of vibration. The left-right (lateral) movement of the wheel 3 is supported by the tension of the leaf spring 6 and the tension of the rod 9. This restrains the degrees of freedom in the three directions.

Next, the force in the rotational direction (rotation around the Z axis) when the wheel 3 is viewed from above is supported by the tension of the leaf spring 6 and the rod 9. The force applied in the twisting direction when the wheel 3 is viewed from the lateral direction is supported by the twisting force of the leaf spring 6. The force applied in the falling direction when the wheel 3 is viewed from the front-rear direction is supported by the spring force (flexing force) of the leaf spring 6 that bends up and down. As a result, the degrees of freedom in the three directions of the wheel are constrained, and together with the degrees of freedom constrained in the three directions, the degrees of freedom in all six directions are constrained, and the suspension is realized.

By the way, the suspension 1 has a rod 9
Even if there is no, only the leaf spring 6 holds. That is, the leaf spring 6 alone can restrain the degrees of freedom in the six directions. However, since the leaf spring 6 is bent at the intersection 6c, the leaf spring 6 does not have sufficient strength against the input in the direction of buckling at the intersection 6c. Therefore, the rod 9 enhances the lateral rigidity.

However, if the rod 9 is used in addition to the leaf spring 6 in order to restrain all the degrees of freedom in the above six directions,
Suspension 1 is over-restrained. Since the one end 6a is fixed to the side member 12, the leaf spring 6 draws a certain arc around the vehicle body side (fixed portion with the side member 12). One end 6a of the leaf spring 6 is fixed to the vehicle body side (rigid connection)
The other end 6b of the wheel side 3 is also fixed to the wheel support member 5. Therefore, the wheel 3 tries to move in accordance with the arc of the leaf spring 6, but the locus of the leaf spring 6 and the locus of the rod 9 at this time do not always coincide with each other, and they interfere with each other.

In order to avoid this interference, it is necessary to elastically support any one of the vehicle body side 6a or the wheel side 6b of the leaf spring 6 or the vehicle body side 9b or the wheel side 9a of the rod 9. Therefore, in the present application, as described above, the ends 8b and 9b of the rods 8 and 9 on the vehicle body side are elastically supported by the elastic member (bush) by the elastic member (bush). In the over-restrained type,
It is possible to escape the excessive restraint by elastically supporting any one of the restraint points.

Further, by extending the leaf spring 6 diagonally rearward to the opposite side across the vehicle center O, the length thereof can be made longer, and accordingly, the angle change position (alignment change) of the wheel 3 is increased. ) Becomes gentler. As a result, stable wheel performance (vehicle body behavior) is obtained. The left wheel 2 is also supported by the leaf spring 7 and the rod 8 in the same manner as the left wheel 3 described above.

At the intersections 6c and 7c of the leaf springs 6 and 7, when the elastic member 14 is not interposed, the left and right wheels 2 and 3 are independently suspended and vertically stroked. , 7c are connected by the elastic member 14, a stabilizer effect can be obtained. For example, in the case of a left turn in which the right wheel 3 bumps and the left wheel 2 rebounds, the stroke amount of the left and right wheels 2, 3 is limited, that is, the body roll is pressed. Considering the spring constant of each wheel 2, 3, in the case of in-phase stroke, the leaf spring 6,
7 is calculated by the bending rigidity of the entire length, but in the case of a reverse phase stroke, only the wheels are closer to the intersections 6c and 7c (more accurately, the springs closer to the wheels 3 and 2 from the intersections 6c and 7c). The bending rigidity is calculated by the sum of the force + the force of the left and right springs from the vehicle body from the intersections 6c and 7c), so that the rigidity is increased.

Further, due to a change in alignment, since the radius of curvature of the locus is small as a short leaf spring with respect to the entire length of the leaf springs 6 and 7, the amount of retraction inside the vehicle body on the front side of the wheel to which the leaf spring is fixed increases. It has a large toe-in characteristic. From the aspect of straightness of the vehicle, it is preferable that the toe change is small in the in-phase, and the toe-in is preferably large in the reverse phase from the aspect of the turning performance. Therefore, it is preferable to interpose the elastic member 14 between the intersecting portions 6c and 7c of the leaf springs 6 and 7 and elastically couple them.

When adjusting the camber change,
Adjustment is performed by changing the plate thickness of the leaf springs 6 and 7. That is, the leaf springs 6 and 7 are formed in a tapered shape over the entire length in the longitudinal direction. For example, if the plate thickness on the one end 6a side (vehicle body side) of the plate spring 6 is thick and the plate thickness on the other end 6b side (wheel support member 3 side) is thin, the rotation center of the wheel support member 3 becomes small and the camber change. Grows larger. On the contrary, when the plate thickness on the one end 6a side (vehicle body side) of the leaf spring 6 is thin and the plate thickness on the other end 6b side (wheel support member 3 side) is thick, the rotation center of the wheel support member 3 increases and the camber The change is small.

When it is difficult to secure the rigidity in the caster direction, one side wheel support member, for example, the right side wheel support member 5 and the right side member 13 is indicated by the dotted line in FIG.
The rod 18 may be added between (the vehicle body side). This rod 18 is vertically offset from the leaf springs 6 and 7,
It is provided so as to face the direction of taking the force mainly applied in the front-back direction,
Remove caster rotation moment. The rod 18
Is added, the interference is increased by that amount, so that it is necessary to elastically support one end of the rod 18.

Further, the leaf springs 6 and 7 may be made of a sheet metal leaf spring member or a resin leaf spring member formed of a resin member.

[0028]

As described above, according to the present invention, in claim 1, as the spring element of the suspension arm,
By using the leaf spring, the coil spring can be eliminated, and moreover, the space in the vertical direction is hardly required, and the space of the vehicle compartment can be widened. Moreover, the number of parts is reduced, and the cost is reduced.
Further, since the leaf spring can have a long length as an arm for supporting the wheel supporting member, the curvature of alignment change becomes gentle, and stable wheel performance (vehicle body behavior) is achieved.
Is obtained.

According to the second and third aspects, since the layout can be symmetrical, the right and left turning characteristics can be matched. In the fourth and fifth aspects, since the intersecting portions of the leaf springs are connected by the elastic member, the stabilizer effect is obtained and the stability is improved. In claim 6, by changing the plate thickness of the plate spring along the longitudinal direction,
The camber change can be adjusted.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing an outline of a rear suspension structure according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a cross-sectional view showing another example of the intersection of the leaf springs 6 and 7 in FIG.

[Explanation of symbols]

 1 Rear suspension 2, 3 Wheels 4, 5 Wheel support members 6, 7 Leaf springs 8, 9, 18 Rods 10, 11 Shock absorbers 12, 13 Side frames 14, 15, 16 Elastic members 17 Brackets

Claims (6)

[Claims] 1. A pair of wheel supporting members for rotatably supporting wheels, one end of which is connected to a vehicle body side, and the other end of which is connected to the wheel supporting members on the opposite side across the center of the vehicle body. A pair of wide leaf spring members arranged so as to intersect each other substantially in the center of the vehicle in a plan view, and one end of each of them is coupled to the vehicle body side, and the other end of each wheel support member on the opposite side across the center of the vehicle body. And a pair of rod members disposed so as to intersect with each other substantially at the vehicle center, and at least one point of the mounting portions of the rod members is elastically supported. Rear suspension structure. 2. The rear suspension structure according to claim 1, wherein one or both of the pair of leaf spring members are bent at an intersection of vehicle centers and are vertically offset. 3. The rear suspension structure according to claim 1, wherein one or both of the pair of rod members are bent and offset at an intersection of vehicle centers. 4. The rear suspension according to claim 2, wherein the pair of leaf spring members are provided with a first elastic member at an intersection of the vehicle center so as to abut both leaf spring members. Construction. 5. A first elastic member is interposed between an upper leaf spring member and a lower leaf spring member at an intersection of the pair of leaf spring members, and the lower leaf plate is attached to the upper leaf spring member. A second elastic member is provided on the connecting member extending to the lower side of the spring member, and the lower plate spring member is sandwiched by the upper plate spring member and the connecting member via both elastic members. The rear suspension structure according to Item 4. 6. The plate spring according to claim 1, wherein the plate spring has a plate thickness gradually changing along a longitudinal direction.
The rear suspension structure according to any one of 4 and 5.