JPH11208233A - Vehicle suspension device - Google Patents

Abstract

An object of the present invention is to provide a suspension device capable of improving the riding comfort by lowering the support rigidity in the front-rear direction while accurately positioning in the front-rear direction by a leaf spring. SOLUTION: A leaf spring 9 is arranged to support a wheel load and extend substantially in the front-rear direction of the vehicle and perform a positioning operation of the wheel 3 in the front-rear direction. While being movably attached, the longitudinal intermediate portion C and the front end portion B are swingably attached to the vehicle body 6 via first and second intermediate members 11 and 13, respectively. The intermediate portion C of the leaf spring 9 is attached to the upper support point 11a and the lower support point 11b
Is attached to the vehicle body 6, and the second intermediate member 13 has an upper support point 13a attached to the vehicle body 6 and a front end of the leaf spring 9 attached to the lower support point 13b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a suspension device used for a vehicle.

[0002]

2. Description of the Related Art A conventional suspension device is disclosed in, for example, Japanese Utility Model Laid-Open No. 3-103804. In this conventional example, a leaf spring member that is disposed substantially in the front-rear direction of the vehicle and supports the vehicle weight is provided between the vehicle body and the lower link, and performs positioning of the lower link in the vehicle front-rear direction, thereby providing a suspension. The positioning operation in the front-rear direction is performed.

[0003]

However, such a conventional suspension apparatus has the following problems. That is, as shown in FIG. 14A, the mounting structure of the leaf spring member on the vehicle body side is such that the opposite end 202 of the leaf spring member 201 on the wheel support side is rigidly connected to the vehicle body 203,
Alternatively, as shown in FIG. 14B, two elastic members 207 and 20 spaced from each other in the longitudinal direction of the leaf spring member 205.
9, the leaf spring members 201 and 205 are attached to the vehicle bodies 203 and 211 with relatively high rigidity in the longitudinal direction, so that the longitudinal rigidity of the suspension is increased. As a result, there is a problem that a shock when the vehicle gets over a protrusion on the road surface is increased, and the riding comfort is deteriorated.

In order to reduce the supporting rigidity of the leaf spring members 201 and 205 in the longitudinal direction by changing the amount of deformation of the elastic members to be large, the leaf spring members 201 and
Since a relatively large preload is applied to No. 5, a problem arises in that the durability of the elastic member is impaired, and there is a limit to greatly lowering the support rigidity and improving the riding comfort.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suspension device capable of improving the ride comfort by reducing the support rigidity in the front-rear direction while ensuring the positioning in the front-rear direction by a leaf spring.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention according to claim 1 supports a wheel load and extends substantially in the front-rear direction of a vehicle to perform a positioning operation of the wheels in the front-rear direction. In a suspension device for a vehicle including a leaf spring, one end of the leaf spring is attached to a wheel support or a suspension link, and a longitudinal intermediate portion of the leaf spring is connected to a first intermediate member. An end is swingably attached to the vehicle body by a second intermediate member. The first intermediate member has an intermediate portion of a leaf spring attached to an upper support point of the intermediate member, and the lower support point is attached to the vehicle body. And the second intermediate member is characterized in that an upper support point of the intermediate member is mounted on the vehicle body side and the other end of the leaf spring is mounted on the lower support point. That.

According to a second aspect of the present invention, there is provided a suspension system for a vehicle including a leaf spring which supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation of the wheel in the front-rear direction. One end of the leaf spring is attached to the wheel support or the suspension link, and the longitudinal middle part of the leaf spring is swung toward the vehicle body by the first intermediate member, and the other end is swung toward the vehicle body by the second intermediate member. The first intermediate member is freely attached, the upper support point of the intermediate member is attached to the vehicle body side, and the intermediate portion of the leaf spring is attached to the lower support point, and the second intermediate member is The upper support point of the intermediate member is attached to the vehicle body side, and the other end of the leaf spring is attached to the lower support point to reduce the input load of the wheel load to the first and second intermediate members. When the W _1, W _2, respectively, between the first support point of the upper and lower portions of the second intermediate member distances S _1,
S ₂ is characterized by comprising a set so as to satisfy the _{W 1 / S 1 <W 2} / S 2 the relationship.

According to a third aspect of the present invention, there is provided a vehicle suspension apparatus including a leaf spring which supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation of the wheel in the front-rear direction. One end of the leaf spring is attached to a wheel support or a suspension link, and a longitudinal middle portion of the leaf spring is swingable on a vehicle body by a first intermediate member, and the other end is swingable by a second intermediate member. Attached to the first intermediate member, an intermediate portion of the leaf spring is attached to an upper support point of the intermediate member, the lower support point is attached to the vehicle body side, the second intermediate member, The other end of the leaf spring is attached to the upper support point of the intermediate member, and the lower support point is attached to the vehicle body to reduce the input load of the wheel load to the first and second intermediate members. Re when the W _1, W _2, first, as between the support points of the upper and lower portions of the second intermediate member distances S _1, S ₂ satisfies _{W 1 / S 1> W 2} / S 2 the relationship It is characterized by being set.

According to a fourth aspect of the present invention, there is provided a suspension system for a vehicle including a leaf spring which supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation of the wheel in the front-rear direction. One end of the leaf spring is attached to a wheel support or a suspension link, and a longitudinal middle portion of the leaf spring is swingably attached to the vehicle body via an intermediate member, and the other end of the leaf spring is Is attached to the vehicle body via an elastic member, wherein the intermediate member has an upper support point of the intermediate member attached to the vehicle body side and an intermediate portion of the leaf spring attached to the lower support point. And

According to a fifth aspect of the present invention, there is provided a suspension system for a vehicle including a leaf spring that supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation of the wheel in the front-rear direction. One end of the leaf spring is attached to a wheel support or a suspension link, a longitudinal middle portion of the leaf spring is attached to the vehicle body via an elastic member, and the other end of the leaf spring serves as an intermediate member. The intermediate member is swingably attached to the vehicle body side, and the other end of the leaf spring is attached to an upper support point of the intermediate member, and the lower support point is attached to the vehicle body side. Features.

According to a sixth aspect of the present invention, there is provided a vehicle suspension device according to any one of the first to fifth aspects,
The intermediate member has opposite ends of the two arms integrated with each other via a rubber bush in which rubber is interposed between the inner and outer cylinders, and is swingably attached to a bracket on the vehicle body side via the rubber bush. The arm is provided with a connecting shaft portion at each of the opposite ends thereof, and the shaft portion swingably supports the plate spring via a rubber bush provided on the plate spring.

According to a seventh aspect of the present invention, in the vehicle suspension device according to the second or fourth aspect, the upper support point is attached to the vehicle body side, and the lower support point is provided between the leaf spring and the intermediate portion. A first intermediate member for attaching the portion, a vehicle body-side member fixed to the vehicle body side and having a concave portion in the center, a leaf spring side member having the central portion attached with the leaf spring, and rubber interposed between the two members; And a core material provided in the rubber, and both ends of which are made of a core material opposed to the two concave portions with a part of the rubber therebetween.

According to an eighth aspect of the present invention, there is provided a vehicle suspension device according to any one of the first to seventh aspects,
One end of the leaf spring is swingably attached to a wheel support or a suspension link.

According to a ninth aspect of the present invention, there is provided a vehicle suspension device according to any one of the first to seventh aspects,
One end of the leaf spring is fixed to a wheel support or a suspension link.

[0015]

According to the first aspect of the present invention, when one end of the leaf spring is displaced in the front-rear direction together with the wheel support or the suspension link, the intermediate portion and the other end of the leaf spring are displaced accordingly. Since the first and second intermediate members are both subjected to a tensile load, a restoring force acts to return the displacement to the leaf spring support points of the two intermediate members, and a reliable positioning operation of the suspension device in the front-rear direction is obtained. Can be

By appropriately selecting the distance between the upper and lower support points of each intermediate member, the restoring force (spring constant in the front-rear direction) can be set small. Riding comfort can be improved.

According to the second aspect of the present invention, since the first intermediate member receives a compressive load and the second intermediate member receives a tensile load, one end of the leaf spring is supported by the wheel support or the suspension. When the link is displaced in the front-rear direction together with the link, a force that promotes the displacement acts on the leaf spring support point (lower support point) of the first intermediate member, and the leaf spring support point (lower support point) of the second intermediate member. , A restoring force acts to pull back the displacement. Since the distance between the support points of the upper and lower portions of each intermediate member is set so that (promoting force) <(restoring force), a reliable positioning operation of the suspension device in the front-rear direction can be obtained. Since the spring constant in the direction can be set smaller, shocks such as when the vehicle gets over a protrusion can be further reduced, and the riding comfort can be improved.

According to the third aspect of the present invention, since the first intermediate member receives a tensile load and the second intermediate member receives a compressive load, one end of the leaf spring has a wheel support or a suspension. When the link is displaced in the front-rear direction together with the link, a restoring force acts on the leaf spring support point of the first intermediate member to pull back the displacement, and a force (negative force) promoting the displacement is applied to the leaf spring support point of the second intermediate member. Restoring force) acts. And
The distance between the support points of the upper and lower portions of each intermediate member is set so that (promoting force) <(restoring force).
The same effect as that of the invention is obtained.

According to the fourth aspect of the present invention, since the intermediate member of the leaf spring intermediate portion receives a compressive load, when one end of the leaf spring is displaced in the front-rear direction together with the wheel support or the suspension link, the intermediate member is moved. A force that promotes the displacement (negative restoring force) acts on the lower support point of the member. Accordingly, a negative restoring force is added to the restoring force of the elastic member at the other end of the leaf spring, and the restoring force is reduced, so that a shock such as when the vehicle gets over a protrusion is relieved and the riding comfort is improved. Can be.

According to the fifth aspect of the present invention, since the intermediate member at the other end of the leaf spring receives a compressive load, when one end of the leaf spring is displaced in the front-rear direction together with the wheel support or the suspension link, A force that promotes the displacement (negative restoring force) acts on the upper support point of the intermediate member. Therefore, the restoring force is a negative restoring force added to the restoring force of the elastic member in the middle portion of the leaf spring, and the restoring force is reduced. it can.

According to the invention of claim 6, according to claim 1,
And an effect equivalent to that of any one of the inventions is obtained.
Since both the upper support point and the lower support point of the intermediate member are attached via the rubber bush, shocks such as when the vehicle gets over a protrusion are effectively absorbed.

According to the invention described in claim 7, according to claim 2,
Alternatively, in the invention according to the fourth aspect, the first intermediate member receiving the compressive load is formed of the rubber material including the core material, the vehicle body side member and the leaf spring side member, so that the material, hardness and length of the rubber are appropriately selected. By doing so, the spring constant in the front-rear direction can be set small, so that the shock when the vehicle gets over a projection can be reduced, and the riding comfort can be improved.

Further, since a concave portion is provided in the vehicle body side member and the plate spring side member opposed to each other with the core member interposed therebetween, the core member can be stably held in the rubber. Can fulfill the role of.

According to the invention described in claim 8, according to claim 1,
And an effect equivalent to that of any one of the inventions is obtained.
Since one end of the leaf spring can swing on the wheel support or the suspension link, the leaf spring is easily flexed in the vertical direction, and the riding comfort is improved.

According to the ninth aspect of the present invention, the first aspect is provided.
And an effect equivalent to that of any one of the inventions is obtained.
Since one end of the leaf spring becomes a fixed end by being fixed to the wheel support or the suspension link, the vertical deflection of the leaf spring can be suppressed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention.
An embodiment will be described with reference to FIGS. 1 to 3 are views showing the configuration of the suspension device of the present embodiment.
4 to 7 are explanatory diagrams. In FIG. 1, the front left side is the inside of the vehicle, and the rear left side is the front of the vehicle.

First, the configuration will be described. As shown in FIG.
The upper end of the wheel support 1 that rotatably supports the right rear wheel 3 is rigidly connected to a bracket 5 b at the lower end of the cylinder of the strut member 5. The strut member 5 has a piston rod head portion 5 a attached to the vehicle body 6, and expands and contracts as the wheels 3 bounce. Thus, the upper end of the wheel support 1 is restrained by the strut member 5.

The lateral link 7 is arranged in the vehicle width direction,
The outer end 7a is attached to the lower part of the wheel support 1 so as to be swingable, while the inner end 7b is attached to the vehicle body 6 so as to be able to swing vertically. Thus, the lateral link 7 positions the wheel support 1 in the vehicle width direction.

The leaf spring 9 is disposed so as to extend obliquely forward from the wheel support 1, and a rear end (one end) A of the leaf spring 9 can swing on the wheel support 1 via a rubber bush 9a described later. Installed. Then, as shown in FIG. 2, the intermediate portion C and the front end (the other end) B of the leaf spring 9 are respectively connected to the first and second intermediate members 11, 13 and the bracket 15,
17 is attached to the vehicle body 6 via a swingable manner.
The brackets 15, 17 are fixed to the vehicle body 6 by bolts 6a, 6b, respectively.

The leaf spring 9 may be attached to a suspension link (not shown) instead of being attached to the wheel support 1.

FIG. 3 shows an attached state of the intermediate portion C of the leaf spring 9. As shown in the drawing, the lower ends of the two arms 11c, 11c opposed to each other are joined to the outer cylinder 11e of the rubber bush 11d to form the first intermediate member 11 integrally. Rubber 11g is baked between the outer cylinder 11e and the inner cylinder 11f. The bolt 12a is placed in the inner cylinder 11f.
Is inserted. In this way, the first intermediate member 11 is fixed to its lower support point 11b by the bolts and nuts 12a and 12b.
Is attached to the vehicle body 6 in a swingable manner. On the other hand, a leaf spring 9 is swingably attached to the upper end of the first intermediate member 11 by bolts and nuts 14a and 14b via a rubber bush 9b formed integrally therewith, and an upper support point 11a is provided. It is configured.

The mounting structure of the upper and lower support points 13a, 13b of the second intermediate member 13 at the front end B of the leaf spring 9 is the same as the mounting structure of the first intermediate member 11. The structure of the rubber bush 9a at the rear end A of the leaf spring 9 and the structure of mounting the wheel spring 1 to the wheel support 1 via the rubber bush 9a are the same as the structure of mounting the lower support point 13b at the front end B.

The distance between the upper and lower support points 11a and 11b and the distance between 13a and 13b of the first and second intermediate members 11 and 13 are set to predetermined dimensions described later.

In this manner, the leaf spring 9 supports the vehicle weight by the spring reaction force and performs the positioning operation of the wheel support 1 in the front-rear direction. The leaf springs 9 may be arranged substantially in the front-rear direction instead of the above-described oblique direction. Conversely, they may be arranged to extend from the wheel support 1 to the rear of the vehicle.

Next, the operation of the suspension device will be described.

Since the leaf spring 9 supports the vehicle weight, a vertical load W is input to the rear end A of the leaf spring 9 as shown in FIG. By this input, the first and second intermediate members 1
The tensile loads W ₁ and W ₂ are input to ₁ and 13, respectively. It is expressed by the following equation of W ₁ and W ₂ .

W ₁ = W (L ₁ + L ₂ ) / L ₂ W ₂ = W · L ₁ / L ₂ where L ₁ is the length between the rear end portion A and the middle portion C, and L ₂ is the middle portion It is the length between C and the front end B. Further, the upper and lower support points 11a of the first intermediate member 11, the length between 11b and S _1, the upper and lower supporting point of the second intermediate member 13 13a, 13b
A length between the S _2.

As shown in FIG. 5, each intermediate member 11, 13
Consider a case in which a small front-back displacement δ occurs in the wheel support 1 with a tensile load applied to the wheel support 1. Both the first and second intermediate members 11 and 13 swing and allow a small displacement δ before and after. In this case, the inclination angle of the axis of the intermediate members 11 and 13 is δ / S in the first intermediate member 11. ₁ , δ in the second intermediate member 13
/ S ₂ . Thus, each intermediate member 11, 13
When the inclination angle of the axis changes, as shown in FIG.
A force component in the longitudinal direction of the leaf spring 9, that is, a longitudinal component, is generated in the force generated in each of the intermediate members 11 and 13.

The magnitude F ₁ of the longitudinal force component of the force generated in the first intermediate member 11 is F ₁ = W ₁ · δ / S ₁ , and the load W _{1 of} the first intermediate member 11 is tensile. since a load, F ₁ acts in a direction to pull back the small displacement δ of the front and rear. Similarly, the magnitude F ₂ of the longitudinal force component of the force generated in the second intermediate member 13 is F ₂ = W ₂ · δ / S ₂ , and the load W _{2 of} the second intermediate member 13 is Since it is a load, F ₂ acts in a direction to pull back the small displacement δ before and after.

Therefore, with the small displacement δ before and after,
A restoring force F in the front-rear direction is generated, and F = F ₁ + F ₂ = (W ₁
/ S ₁ + W ₂ / S ₂ ) δ. That is, this is caused by the action of the intermediate members 11 and 13, and the equivalent spring constant K =
This indicates that (W ₁ / S ₁ + W ₂ / S ₂ ) can be considered to exist. By the action of this equivalent spring, a restoring force acts on the displacement of the leaf spring 9 in the front-rear direction, and the position of the leaf spring 9 can be reliably determined. Also,
By appropriately selecting the distances S ₁ and S ₂ between the upper and lower support points of the first and second intermediate members 11 and 13, the equivalent spring constant K in the front-rear direction can also be reduced.

FIG. 7A shows the shape of the leaf spring 9 and the state of the vertical load when the vehicle is fully bound.
FIG. 3B shows the state when the vehicle is fully rebounded. During full bounce Figure 7a, the load W which is input to the rear end A of the plate spring 9 'is larger than the load W when the normal posture, therefore, W ₁ of each intermediate member 11, 13',
W ₂ ′ is also larger than the load in the normal posture.

As a result, the equivalent spring effect becomes larger than in the normal posture, and the front-rear rigidity of the suspension increases in the full-bound posture in which the input to the suspension tends to increase. I have.

In a normal vehicle, since a rebound stopper is separately provided to limit the rebound stroke of the suspension, W ″ of the leaf spring 9 does not become zero even at the time of full rebound. Since the residual load is applied, the tensile loads W ₁ ″ and W ₂ ″ are also applied to the respective intermediate members 11 and 13, so that it is possible to maintain an appropriate suspension support rigidity in the front-rear direction.

Thus, according to the present embodiment, when the rear end portion A of the leaf spring is displaced in the front-rear direction together with the wheel support 1, for example, the intermediate portion c and the front end portion B of the leaf spring 9 are displaced accordingly. Since both intermediate members 11 and 13 are both subjected to a tensile load, the leaf spring support point 1 of both intermediate members 11 and 13
A restoring force acts on 1a and 13b to return the displacement, and a reliable positioning operation of the suspension device in the front-rear direction can be obtained.

Further, the restoring force (supporting rigidity) can be set small by appropriately selecting the distances S ₁ and S ₂ between the upper and lower support points of the intermediate members 11 and 13, so that the vehicle can be used when the vehicle goes over a protrusion. It can reduce shocks and improve ride comfort.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing a configuration of the suspension device of the present embodiment. This embodiment is different from the first embodiment in that a leaf spring is rigidly connected to a wheel support, and the other configuration is the same as the first embodiment. Therefore, only the differences will be described, and redundant description will be omitted.

As shown in FIG. 8, the leaf spring 29 is fixed to the wheel support 21 at its rear end A.

With such a configuration, when the leaf spring 29 supports the vehicle weight, the load acting on the first and second intermediate members 31, 33 is limited only by the geometrical relationship as in the first embodiment. Can not be obtained, but each intermediate member 31, 33
Are subjected to tensile loads _W1a and _W2a .

Thus, also in this embodiment, an equivalent spring constant K = (W _1a / S ₁ + W _2a / S ₂ ) exists due to the action of the intermediate members 31 and 33 as in the first embodiment. By the action of this equivalent spring, a restoring force acts on the displacement of the leaf spring 29 in the front-rear direction, and the position of the leaf spring 29 can be reliably determined.

Further, by appropriately selecting the lengths S ₁ and S ₂ between the support points of the intermediate members 31 and 33, the equivalent spring constant K in the front-rear direction can be reduced.

[Third Embodiment] A third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a diagram conceptually showing a mounting structure of a leaf spring of the suspension device of the present embodiment to a vehicle body. This embodiment is different from the above-described first embodiment (FIG. 2) in the mounting structure of the intermediate portion of the leaf spring to the vehicle body, and the other configuration is the same as the first embodiment. Therefore, this difference will be described, and redundant description will be omitted.

As shown in FIG. 9, the intermediate portion C of the leaf spring 49
Is attached to the vehicle body 6 via the first intermediate member 51 so as to be swingable. However, unlike the first embodiment, the leaf spring 49 is swingable to the lower support point 51b of the first intermediate member 51. And the upper support point 5 of the first intermediate member 51
1a is swingably attached to the vehicle body 6 side. The method of supporting the front end B of the leaf spring 49 is the same as in the first embodiment.

The first and second intermediate members 51, 53
The distances S ₁ and S ₂ between the upper and lower support points are set so as to satisfy the relationship of W ₁ / S ₁ <W ₂ / S ₂ unlike the first embodiment. W ₁ and W ₂ are loads applied to the first and second intermediate members 51 and 53.

With such a support structure, the compressive load W ₁ is input to the first intermediate member 51 and the second intermediate member 5
3, a tensile load is input. While the front-rear direction of the spring effect generated by the load acting on each intermediate member 51 and 53 is similar to the principle shown in FIG. 6, since the load acting on the first intermediate member 51 is a compression load W _1, When the longitudinal displacement δ occurs in the first intermediate member 51, the longitudinal component W ₁ · δ / S ₁ that acts acts in a direction that promotes the displacement δ.

Therefore, according to the present embodiment, the spring effect generated by the first intermediate member 51 on the longitudinal displacement of the leaf spring 49 is a negative spring effect. Since the spring effect generated by the second intermediate member 53 is in the direction of restoring the spring constant of W ₂ / S ₂ , the equivalent support rigidity in the front-rear direction is K = (W ₂ / S ₂ ) − (W ₁ / S ₁ ), (K> 0 due to the above condition setting), the positioning in the front-rear direction is reliably performed, and the equivalent spring constant in the front-rear direction is different from that of the first and second embodiments. By reducing the size, shocks such as when riding over a protrusion can be further alleviated, and riding comfort can be improved.

[Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a view conceptually showing a mounting structure of a leaf spring of the suspension device of the present embodiment to a vehicle body. This embodiment is different from the first embodiment (FIG. 2) in the mounting structure of the front end portion B of the leaf spring to the vehicle body.
Other configurations are the same as those of the first embodiment. Therefore, this difference will be described, and redundant description will be omitted.

As shown in FIG. 10, the intermediate portion C of the leaf spring 69 is provided with a first intermediate member 71 as in the first embodiment.
The lower support point 71b of the first intermediate member 71 is swingably attached to a bracket 75 extending downward from the vehicle body.

Unlike the first embodiment, the front end portion B of the leaf spring 69 is swingably attached to the upper support point 73a of the second intermediate member 73, and the lower support point 73b of the second intermediate member 73. Is fixed to the vehicle body, and is swingably attached to a bracket 77 extending downward.

Then, the first and second intermediate members 71 and 73
The distance between the upper and lower support points S ₁ and S ₂ is W ₁ / S ₁ > W ₂
/ S ₂ . W ₁ ,
W ₂ is a load applied to the first, second intermediate members 71 and 73.

The first intermediate member 71 receives a tensile load W ₁ , and the second intermediate member 73 receives a compressive load W ₂ . Since although the longitudinal direction of the spring effect generated by the load acting on the intermediate member 71 and 73 is similar to the principle shown in FIG. 6, the compressive load W ₂ is input to the second intermediate member 73, the second When the longitudinal displacement δ occurs in the intermediate member 73,
The generated longitudinal component W ₂ · δ / S ₂ acts in a direction that promotes the displacement δ.

Therefore, according to the present embodiment, the spring effect generated by the second intermediate member 73 on the longitudinal displacement of the leaf spring 69 is a negative spring effect. Since the spring effect generated by the first intermediate member 71 is in the direction of restoring the spring constant of W ₁ / S ₁ , the equivalent support rigidity in the front-rear direction is K = (W ₁ / S ₁ ) − (W ₂ / S ₂ ), (K> 0 due to the above condition setting), the positioning in the front-rear direction is reliably performed, and the equivalent spring constant in the front-rear direction is different from that of the first and second embodiments. By reducing the size, shocks such as when riding over a protrusion can be further alleviated, and riding comfort can be improved.

[Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a diagram showing a structure of attaching the leaf spring of the suspension device of the present embodiment to the vehicle body.

As shown in FIG. 11, the intermediate portion C of the leaf spring 89 is connected to the lower support point 9 of the first intermediate member (intermediate member) 91.
1b is swingably attached via a rubber bush 9b, and an upper support point 91a of the first intermediate member 91 is swingably attached via a rubber bush 11d to a bracket 6b fixed to the vehicle body 6. . The front end B of the leaf spring 89 is attached to the vehicle body 6 via a rubber bush (elastic member) 9a.

With this configuration, according to the present embodiment, the compressive load W ₁ is input to the first intermediate member 91. Accordingly, the spring effect caused by the compression load W ₁ that acts on the first intermediate member 91 with respect to longitudinal displacement of the leaf spring 89, a negative spring effect of the magnitude of W ₁ / S _1.
If the rigidity in the front-rear direction of the rubber bushing 9a and K _b, equivalent support rigidity of the front and rear _{direction, K = K b - (W} 1 /
S ₁ ), and the spring constant in the front-rear direction is smaller than that in the conventional example, so that the shock at the time of climbing over a protrusion or the like can be reduced, and the riding comfort can be improved.

As in this embodiment, the upper support point 91a of the first intermediate member 91 is swingably attached to the bracket 6b fixed to the vehicle body 6 via the rubber bush 11d, and receives a compressive load. In the case of the configuration, for example, the following elastic support member may be used instead of the first intermediate member 91.

FIG. 13 shows an embodiment of the elastic support member. The elastic support member 121 includes a base portion (body-side member) 1
27 is fixed to the vehicle body 6 by bolts 129. A lower support point (leaf spring side member) 125 for supporting a leaf spring is provided at the lower end of the elastic support member 121, and a rubber portion 131 is provided between the elastic support member 121 and the base 127. And the rubber part 13
1 includes an insert (core material) 123 made of a plate-like metal or the like as shown in the figure. Concave portions 127a and 125a as shown are formed at the center of the base portion 127 facing the upper and lower ends of the insert 123 and the lower support point 125, respectively, and a rubber portion 131 is provided between the upper and lower ends of the insert 123. It is formed with interposition. Thus, the insert 123 is stably held in the rubber portion 131,
Plays the role of reinforcement against compressive loads.

With such a structure, when the lower support point 125 of the elastic support member 121 receiving the compressive load is displaced in the front-rear direction together with the vehicle body support, the rubber portion 13 is accordingly moved.
1 exerts a restoring force to return the displacement to the leaf spring, thereby obtaining a positioning function of the vehicle body support in the front-rear direction, and restoring by appropriately selecting the material, hardness and length of the rubber portion 131. Since the force can be set to a small value, it is possible to relieve a shock such as when the vehicle gets over a protrusion and improve the ride comfort.

[Sixth Embodiment] A sixth embodiment of the present invention will be described with reference to FIG. FIG. 12 is a view showing a structure for attaching a leaf spring of the suspension device of the present embodiment to a vehicle body.

As shown in FIG. 12, the intermediate portion C of the leaf spring 109 is connected to the vehicle body 6 via a rubber bush (elastic member) 9b.
The front end portion B of the leaf spring 109 is swingably attached to an upper support point 113a of a second intermediate member (intermediate member) 113 via a rubber bush 9b, and a lower support point of the second intermediate member 113. 113b is swingably attached to a bracket 117 extending downward from the vehicle body 6.

With such a configuration, according to the present embodiment, the compression load W ₂ is input to the second intermediate member 113. Accordingly, the second displacement with respect to the longitudinal displacement of the leaf spring 109 is
Spring effect caused by compressive load W ₂ acting on the intermediate member 113, a negative spring effect of the magnitude of W ₂ / S _2. If the rigidity in the front-rear direction of the rubber bushing 9b and K _b, equivalent support rigidity of the front and rear _{direction, K = K b - (W} 2
/ S ₂ ), and the spring constant in the front-rear direction is smaller than that of the conventional example, so that the shock at the time of climbing over a protrusion or the like can be reduced, and the riding comfort can be improved.

In each of the above embodiments, the strut member 5 restrains the upper region of the wheel support 1 and the leaf springs 9, 29, 49, 6 restrain the wheel support 1 in the toe angle direction.
Although the configuration performed at 9, 89, and 109 has been described, the upper region of the wheel support may be restricted by providing an upper arm, and the restriction in the toe angle direction may be performed by providing another link.

Also, without attaching the leaf spring to the wheel support,
You may attach to a link member. In this case, the attachment method of the link member and the leaf spring may be changed, but the leaf spring is a suspension device that supports all or a part of the vehicle weight, and the leaf spring is arranged in the front-rear direction of the wheel support. With the configuration that performs the positioning operation, the same operation and effect as the present invention can be obtained.

Further, as the first and second intermediate members, instead of the shackle member as shown in FIG. 3, any structure can be used as long as it can transmit a load in a substantially vertical direction in a certain axial direction. Depending on the structure of the suspension (restriction of the degree of freedom), a so-called connecting rod member is connected on both sides by a spherical joint, or only one side is connected by a spherical joint and the other side is rotatably connected around a specific axis. Such an intermediate member may be used.

In the first and second embodiments, the structure of the non-steered wheel suspension device is shown, but the present invention is also applicable to steered wheels. Further, although the leaf spring is arranged to extend obliquely forward from the wheel support 1, a similar effect can be obtained if it is arranged to extend rearward of the vehicle.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a view illustrating a mounting structure of a leaf spring according to the first embodiment.

FIG. 3 is a diagram illustrating a mounting structure of a central portion of a leaf spring according to the first embodiment.

FIG. 4 is an explanatory diagram of the first embodiment.

FIG. 5 is an explanatory diagram of the first embodiment.

FIG. 6 is an explanatory diagram of the first embodiment.

FIG. 7 is an explanatory diagram of the first embodiment.

FIG. 8 is a configuration diagram of a second embodiment of the present invention.

FIG. 9 is a view conceptually showing a mounting structure of a leaf spring according to a third embodiment of the present invention.

FIG. 10 is a view conceptually showing a mounting structure of a leaf spring according to a fourth embodiment of the present invention.

FIG. 11 is a view showing a mounting structure of a leaf spring according to a fifth embodiment of the present invention.

FIG. 12 is a view showing a leaf spring mounting structure according to a sixth embodiment of the present invention.

FIG. 13 is a diagram illustrating an example of an intermediate member that receives a compressive load.

FIG. 14 is a view showing a mounting structure of a conventional leaf spring.

[Explanation of symbols]

1, 21 Wheel support 3 Wheel 6 Body 9, 29, 49, 69, 89, 109 Leaf spring 9a, 9b, 11d Rubber bush (elastic member) 11, 31, 51, 71, 91 First intermediate member 11a, 13a, 51a, 71a, 73a, 91a, 1
13a Upper support point 11b, 13b, 51b, 71b, 73b, 91b, 1
13b Lower support point 11c Arm 13, 33, 53, 73, 113 Second intermediate member 15, 17, 117 Bracket 121 Elastic support member 123 Insert (core material) 125 Lower support point (leaf spring side member) 125a, 127a Recess 127 Base part (body side member) 131 Rubber part A Rear end (one end) of leaf spring B Front end (other end) of leaf spring C Middle part of leaf spring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiteru Minagawa Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa

Claims (9)

[Claims] 1. A suspension device for a vehicle, comprising a leaf spring that supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation in the front-rear direction of the vehicle, wherein the leaf spring is one end of the leaf spring. Is attached to a wheel support or a suspension link, and a longitudinally intermediate portion of the leaf spring is swingably attached to the vehicle body by a first intermediate member, and the other end is attached to a vehicle body by a second intermediate member. In the first intermediate member, an intermediate portion of a leaf spring is attached to an upper support point of the intermediate member, and the lower support point is attached to the vehicle body. The second intermediate member has an upper support point of the intermediate member. A suspension device for a vehicle, wherein the suspension device is attached to a vehicle body and the other end of a leaf spring is attached to the lower support point. 2. A suspension system for a vehicle, comprising: a leaf spring that supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation in the front-rear direction of the vehicle. Is attached to a wheel support or a suspension link, and a longitudinally intermediate portion of the leaf spring is swingably attached to the vehicle body by a first intermediate member, and the other end is attached to a vehicle body by a second intermediate member. In one intermediate member, an upper supporting point of the intermediate member is attached to the vehicle body side, and an intermediate portion of the leaf spring is attached to the lower supporting point, and the second intermediate member is an upper supporting point of the intermediate member. Is attached to the vehicle body side, and the other end of the leaf spring is attached to the lower support point, and the input loads of the wheel loads to the first and second intermediate members are W ₁ and W ₂ , respectively. At this time, the distances S ₁ and S ₂ between the upper and lower support points of the first and second intermediate members are W ₁ / S ₁ <W
Suspension apparatus for vehicles according to claim set be to satisfy ₂ / S ₂ the relationship. 3. A suspension device for a vehicle, comprising a leaf spring that supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation in the front-rear direction of the vehicle, wherein the leaf spring is one end of the leaf spring. Is attached to a wheel support or a suspension link, and a longitudinally intermediate portion of the leaf spring is swingably attached to the vehicle body by a first intermediate member, and the other end is attached to a vehicle body by a second intermediate member. The intermediate member has an intermediate portion of the leaf spring attached to an upper support point of the intermediate member, and the lower support point is attached to the vehicle body, and the second intermediate member has an upper support point of the intermediate member. The other end of the leaf spring is attached, the lower support point is attached to the vehicle body side, and the input loads of the wheel load to the first and second intermediate members are W ₁ and W ₂ , respectively. And the distances S ₁ and S ₂ between the upper and lower support points of the first and second intermediate members are W ₁ / S ₁ > W
Suspension apparatus for vehicles according to claim set be to satisfy ₂ / S ₂ the relationship. 4. A suspension apparatus for a vehicle, comprising a leaf spring that supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation in the front-rear direction of the vehicle, wherein the leaf spring is one end of the leaf spring. Is attached to a wheel support or a suspension link, a longitudinal middle portion of the leaf spring is swingably attached to the vehicle body side via an intermediate member, and the other end of the leaf spring is attached to the vehicle body via an elastic member. A suspension device for a vehicle, wherein the intermediate member has an upper support point of the intermediate member attached to the vehicle body and an intermediate portion of the leaf spring attached to the lower support point. 5. A suspension apparatus for a vehicle, comprising a leaf spring that supports a wheel load and extends substantially in the front-rear direction of the vehicle and performs a positioning operation in the front-rear direction of the vehicle, wherein the leaf spring is one end of the leaf spring. Is attached to a wheel support or a suspension link, a longitudinal middle portion of the leaf spring is attached to the vehicle body via an elastic member, and the other end of the leaf spring swings toward the vehicle body via the intermediate member. A suspension device for a vehicle, wherein the intermediate member has the other end of the leaf spring attached to an upper support point of the intermediate member, and the lower support point is attached to a vehicle body. . 6. The vehicle suspension device according to claim 1, wherein the intermediate member includes a rubber bush in which rubber is interposed between inner and outer cylinders at opposite ends of two arms. The arm is swingably attached to the bracket on the vehicle body side via the rubber bush, and the other end of the arm is provided with a connecting shaft portion, and the shaft portion is connected to the leaf spring. A suspension device for a vehicle, wherein the leaf spring is swingably supported via a rubber bush provided. 7. The vehicle suspension device according to claim 2, wherein the upper support point is mounted on a vehicle body side, and a middle portion of the leaf spring is mounted on the lower support point. The member is a vehicle body-side member fixed to the vehicle body side and having a concave portion in the center, a plate spring side member having the concave portion mounted in the center and attaching the plate spring, a rubber interposed between the two members, and provided in the rubber. A suspension device for a vehicle, wherein both end portions are made of a core material opposed to the two concave portions with a part of the rubber therebetween. 8. The suspension device for a vehicle according to claim 1, wherein one end of the leaf spring is swingably attached to a wheel support or a suspension link. Vehicle suspension device. 9. The vehicle suspension device according to claim 1, wherein one end of the leaf spring is fixed to a wheel support or a suspension link. apparatus.