JP2008273402A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device restraining a large displacement of a wheel while lowering longitudinal rigidity for supporting the wheel. <P>SOLUTION: An axle 2 is connected with a suspension member 3, and two lower links 4, 5 aligned in a vehicle longitudinal direction are connected with each other by two connecting bushes 20, 21. The wheel side connecting bush 20 is coupled with a first mounting bush 9 connecting the front lower link 4 to the axle by fastening. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

As a conventional rear wheel suspension device, for example, there is a device described in Patent Document 1. In this apparatus, the lower region of the wheel support member and the vehicle body side member are connected to each other, and the pair of rigid arms arranged at intervals in the vehicle front-rear direction and the pair of rigid arms are respectively rigidly connected to the pair of rigid arms. And a coupling member constructed between the rigid arms. The coupling member is formed of a flat plate-shaped steel plate extending in the vehicle front-rear direction so as to be deformable in a direction parallel to the plane including the connecting portion to the vehicle body side member and the wheel support member.
As a result, the longitudinal rigidity for supporting the wheel is lowered and the toe characteristic at that time is optimized.
JP 62-234705 A

The wheel needs to be displaced to some extent in consideration of the riding comfort and the like, but if the amount of displacement becomes too large, harmful effects will occur, and it is necessary to regulate a large displacement.
However, since there is nothing in the prior art that regulates the amount of deformation of the coupling member, a means for regulating the displacement in the front-rear direction is required separately.
The present invention has been made paying attention to the above points, and it is an object of the present invention to regulate large displacement of a wheel while lowering the longitudinal rigidity for supporting the wheel.

  In order to solve the above-mentioned problems, the present invention connects a wheel support member and a vehicle body side member and swings two links arranged side by side in the vehicle front-rear direction by one or more elastic connecting portions. It connects so that one of the 1 or 2 or more elastic connection parts may be connected to the said one link via the connection part to the wheel support member in one link of two links.

  According to the present invention, the large displacement of the wheel can be regulated while reducing the longitudinal rigidity for supporting the wheel.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a top view showing a suspension device for a rear wheel according to the present embodiment, and FIG. 2 is a schematic diagram for explaining the arrangement of links as viewed from the front of the vehicle.
(Constitution)
The suspension device includes two lower links 4 and 5 that connect between a lower region of an axle 2 that rotatably supports a wheel 1 and a suspension member 3 that is a vehicle body member, an upper region of the axle 2, and a suspension. And an upper link 8 connecting the member 3.

  The two lower links 4 and 5 are attached to the axle 2 by a single bushing 9 and 10 so as to be swingable up and down, and also to the suspension member 3 by a single bushing 11 and 12, respectively. It is connected so that it can swing up and down. The upper link 8 is also attached to the axle 2 so as to be swingable up and down by one bush 13 and is also connected to the suspension member 3 so as to be swingable up and down by one bush 14.

The two lower links 4 and 5 are arranged so as to be aligned in the longitudinal direction of the vehicle and are connected to each other so as to be able to swing only within a predetermined range. When the two lower links 4 and 5 are described separately, the lower link 4 on the front side in the vehicle front-rear direction is referred to as the front lower link 4 and the lower link 5 on the rear side in the vehicle front-rear direction is referred to as the rear lower link 5. I will decide.
Each of the bushes 9 to 14 is configured such that an elastic body made of a rubber body is interposed between an outer cylinder and an inner cylinder arranged in a nested manner. In the present embodiment, the outer cylinder is fixed to the ends of the links 4, 5, and 8, and the inner cylinder is attached to the suspension member 3 or the axle 2 via bolts.

The front lower link 4 is a rod-like member extending linearly along the link axis L1, and the bushes 9 and 11 having the above-described configuration are provided at both end mounting portions thereof.
The rear lower link 5 is integrated with the link main body portion 6 extending along the link axis L2 and the link main body portion 6 and is connected to the front lower link 4 from the link main body portion 6 toward the front lower link 4. And a projecting portion 7 projecting forward in the direction. The overhang 7 is a plate-like member, for example, and has a substantially trapezoidal shape when viewed from above.

A front end portion of the overhanging portion 7 facing the front lower link 4 in the vehicle front-rear direction is connected to the front lower link 4 via two bushes 20 and 21 arranged offset in the vehicle width direction. .
In the following description, the bushes 20 and 21 that connect the two lower links 4 and 5 are referred to as connect bushes 20 and 21. The bushes 9 to 12 that connect the lower links 4 and 5 to the axle 2 and the suspension member 3 are referred to as mounting bushes 9 to 12.

The two connect bushes 20 and 21 are arranged with their axes substantially in the vehicle front-rear direction when viewed from above. Here, when distinguishing between the two connect bushes 20, 21, the wheel-side connect bush 20 is referred to as a wheel-side connect bush 20, and the vehicle-body-side connect bush 21 is referred to as a vehicle-body-side connect bush 21.
The vehicle body side connect bush 21 has an outer cylinder fixed to the midway position of the front lower link 4 in the axial direction, and an inner cylinder fixed to the projecting portion 7 via a mounting bolt.

The wheel-side connect bush 20 is connected to the front lower link 4 via an attachment bush 9 disposed at the wheel side end of the front lower link 4. Here, the mounting bush 9 disposed at the wheel side end of the front lower link 4 is referred to as a first mounting bush 9.
The wheel side connect bush 20 is connected to the front lower link 4 via the first mounting bush 9, for example, the wheel side connect bush 20 and the first mounting bush 9 are attached to the axle 2 by tightening together. This is realized.

Next, the joint fastening structure for the axle 2 of the wheel-side connect bush 20 and the first mounting bush 9 will be described.
As described above, the first mounting bush 9 is configured such that an elastic body made of a rubber body is interposed between an outer cylinder and an inner cylinder arranged in a nested manner. As shown in FIG. 2, the first mounting bush 9 is configured such that the outer cylinder 9 a is fixed to the wheel side end of the front lower link 4, and the inner cylinder 9 b is provided on the axle 2 via the bolt 31. It is attached to the U-shaped bracket 30 in a both-sided state. That is, the U-shaped bracket 30 includes two side wall portions 30a arranged in the vehicle longitudinal direction. The first mounting bush 9 is disposed between the two side wall portions 30a, and the mounting bolt 31 penetrating the inner cylinder 9b is fixed to the two side wall portions 30a. In FIG. 2, reference numeral 31 a represents the head of the bolt, and reference numeral 32 represents a nut that is screwed to the shaft portion of the bolt 31.

Here, the inner cylinder 9b of the first mounting bush 9 protrudes toward the rear lower link 5 and also serves as the inner cylinder of the wheel-side connect bush 20.
A wheel side front portion (hereinafter referred to as a protruding front end portion 7 a) in front of the vehicle front-rear direction in the protruding portion 7 is disposed in the U-shaped bracket 30. By forming an annular hole concentric with the inner cylinder 9b in the projecting front end 7a, an outer cylinder 20a of the wheel-side connect bush 20 is formed in the projecting front end 7a.

  The hole diameter of the outer cylinder portion 20a is set to be equal to or substantially equal to the inner diameter of the outer cylinder 9a of the first mounting bush 9. The hole diameter of the outer cylinder portion 20a may be different from the inner diameter of the outer cylinder 9a of the first mounting bush 9. In short, the end surface of the outer cylinder part 20a should just oppose the outer cylinder 9a of the 1st attachment bush 9 in a bush axial direction (vehicle front-back direction). And between the outer cylinder part 20a and the inner cylinder 9b, the elastic body 20c of the connection side which consists of rubber materials is interposed. The connecting-side elastic body 20c has a cylindrical shape, and an inner diameter surface is set to a shape and a diameter capable of press-fitting the inner cylinder 9b. Note that the connecting-side elastic body 20c may be slidably assembled to the inner cylinder 9b.

  Further, an annular recess 20d into which the outer cylinder portion 20a can be fitted is formed on the outer diameter surface of the elastic body 20c on the connect side, and the outer cylinder portion 20a is fitted into the recess 20d. The elastic body 20c on the connection side is assembled to the projecting front end portion 7a which is the outer cylinder portion 20a. The connect-side elastic body 20c is longer in the axial direction than the outer cylinder portion 20a, and the first mounting bush 9 side has a diameter that can be press-fitted into the outer cylinder of the first mounting bush 9, and a convex portion 20e. It has become.

Then, as shown in FIG. 3, the wheel-side connect bush 20 is fitted by inserting the convex portion 20 e of the elastic body 20 c by press-fitting between the outer cylinder 9 a and the inner cylinder 9 b of the first mounting bush 9. 1 It is connected to the front lower link 4 via an attachment bush 9.
At this time, the elastic body portions 20 f located on both sides of the outer cylinder portion 20 a are configured to be interposed between the outer cylinder portion 20 a and the outer cylinder 9 a of the first mounting bush 9.
As described above, the front lower link 4 and the rear lower link 5 are connected to each other in a three-dimensional manner by the connection bushes 20 and 21 that are elastic connection portions, and the amount of the swing is also determined by the connection bushes 20 and 21. 21 is regulated by the span between the outer cylinder and the inner cylinder and the rigidity of the elastic body.

The rigidity of the connection bushes 20 and 21 is set to be lower than the rigidity of the mounting bushes 9 to 12.
Here, the axle 2 constitutes a wheel support member, and the suspension member 3 constitutes a vehicle body side member. The connect bushes 20 and 21 constitute an elastic connection part. The rear lower link 5 constitutes the first link, and the front lower link 4 constitutes the second link. The outer cylinder portion 20 a constitutes an outer cylinder of the wheel side connect bush 20. The 1st attachment bush 9 comprises the connection part to the wheel support member of a 2nd link.
(Function and effect)
(1) By connecting the two lower links 4 and 5 to each other, the vehicle front-rear direction input to the wheel 1 can be received by the two lower links 4 and 5. For this reason, in order to receive the said vehicle front-back direction input, it is not necessary to provide another link.
In addition, even if the two lower links 4 and 5 are connected to each other in this way, the connecting portion is configured to be swingable only within a predetermined swing range by the connect bushes 20 and 21, thereby The two lower links 4 and 5 are connected in a state that can swing at least a predetermined swing range in the vehicle width direction with respect to an input in the vehicle longitudinal direction.

  As a result, the elastic bodies of the connection bushes 20 and 21 constituting the elastic connecting portion are deflected with respect to the longitudinal input to the wheel 1 (front and rear input to the wheel center W / C) due to road surface irregularity. In the connect bushes 20, 21, the inner cylinder swings and displaces in the vehicle width direction while slightly swinging in the vehicle front-rear direction relative to the outer cylinder. As a result, the substantially trapezoidal shape connecting the four wheel side attachment points P2 and P4 and the vehicle body side attachment points P1 and P3 of the two lower links 4 and 5 in the top view changes, and the two lower links connected to each other. The rigidity of the axle 2 supported by the links 4 and 5 in the longitudinal direction of the vehicle is set low. For this reason, the ride comfort is improved, in particular, the shock when riding over the protrusion is reduced.

Further, since the connection bushes 20 and 21 do not swing any more if the elastic body is bent more than a predetermined amount, it is possible to prevent the connection bushes 20 and 21 from swinging more than necessary without providing another member.
In addition, since the connection bushes 20 and 21 are absorbed by bending with respect to the input in the front-rear direction, and attenuation is also obtained by the characteristics of the rubber of the connect bushes 20 and 21, the vibration of the front-rear direction input is good. Further, even if the lower links 4 and 5 are designed so as to satisfy the strength, the rigidity in the front-rear direction is determined by the rigidity of the connect bushes 20 and 21, so that the degree of freedom in design can be increased.

(2) Since the rigidity of the input and output in the front and rear direction can be set low by bending the connection bushes 20 and 21 with respect to the input and output from the front and rear direction to the wheel 1 in this way, the two lower links 4 and 5 are connected. Even if the two lower links 4 and 5 receive the longitudinal input to the wheel 1, in order to reduce the shock due to road surface irregularities, the wheel side attachment points P2 of the two lower links 4 and 5 There is no need to set the rigidity of the mounting bushes 9 to 12 constituting the P4 and the vehicle body side mounting points P1 and P3 low. That is, the rigidity of the mounting bushes 9 to 12 of the lower links 4 and 5 can be set high. Therefore, by setting the rigidity of the mounting bushes 9 to 12 of the lower links 4 and 5 high, the lateral rigidity (rigidity in the vehicle width direction) of the axle 2 can be increased, and this also increases the camber rigidity. As a result, the steering stability can be improved. In addition, since the lateral direction input to the wheel 1 is applied to the two lower links 4 and 5 substantially in the direction of the link axes L1 and L2, the lateral rigidity of the axle 2 is set even if the rigidity of the connect bushes 20 and 21 is set low. Never lower. As a result, it is possible to achieve both a low rigidity in the front-rear direction and a high rigidity in the lateral direction, and it is possible to achieve a higher level of riding comfort and handling stability.

(3) When a braking force in the vehicle front-rear direction is input to the ground contact surface of the wheel 1 by a braking operation or the like, a moment in the windup direction is generated by the input. Due to this moment, an upward force acts on the rear lower link 5 connected to the axle 2, and a downward force acts on the front lower link 4, so that at the connecting portion of both the lower links 4, 5. A vertical force is also input to a certain connect bush 20, 21.

When the rigidity of the connection bushes 20 and 21 separated in the vehicle width direction is set to be high with respect to the vehicle longitudinal direction input to the wheel 1 as described above, the two lower links 4 and 5 are elastic members. Even if it connects via, it becomes possible to make the rigidity of a windup direction high.
On the contrary, if the vertical rigidity of the connection bushes 20 and 21 is set to be low, the connection bushes 20 and 21 positively and repeatedly deform when the two lower links 4 and 5 are input in the windup direction. Thus, vibration energy can be absorbed, and vibration transmitted from the suspension to the vehicle body can be reduced.

(4) In the present embodiment, of the two points (the set position of the connect bush) that connects the two lower links 4 and 5 in a swingable manner, the connecting point on the wheel side (the wheel side connect bush 20) is The front lower link 4 is structured to be fastened together with the first mounting bush 9 that constitutes a connection point to the axle 2.
For this reason, the vehicle body side connect bush 21 tends to have a cantilevered support structure as the number of parts is reduced, but the wheel side connect bush 20 is supported by the axle 2 via brackets 30 on both sides of the bolt 31. This is a double-supported mounting structure (see FIG. 2). For this reason, it is easy to reduce the weight of the connecting structure using the wheel-side connect bush compared to the connecting structure between the overhanging portion 7 and the front lower link 4 using the vehicle body-side connect bush 21.
Moreover, by using a co-tightening structure, the number of parts can be reduced by sharing bolts and the like with the first mounting bush 9.
As a result, the weight of the vehicle and the number of parts can be reduced.

(5) Even if the wheel-side connect bush 20 is configured to be fastened together with the first mounting bush 9, an elastic body is provided between the outer cylinder portion 20 a of the wheel-side connect bush 20 and the outer cylinder 9 a of the first mounting bush 9. By disposing the portion 20f, the overhanging front end 7a can be reliably swung with respect to the front lower link 4. As a result, the low suspension longitudinal rigidity as described above can be realized.
In the present embodiment, as shown in FIG. 2, the elastic body portion is also interposed between the side wall portion 30 a and the outer cylinder portion 20 a, so that the rocking is further possible.

(6) When the connecting point of the two lower links 4 and 5 is elastically connected at a single point, the two lower links 4 and 5 are relatively displaced such as being relatively twisted. There is a fear. On the other hand, in this embodiment, even if two lower links 4 and 5 are elastically connected by elastically connecting two points offset in the vehicle width direction, The relative fluctuation can be suppressed within a predetermined range, and the load at each connection point can be reduced.
In particular, since the connecting point on the wheel side is located at the wheel side end of the front lower link 4 or in the vicinity thereof, the distance between the two connect bushes 20 and 21 can be increased, and the twisting direction is increased accordingly. It becomes possible to reduce the load of each connection bush 20 and 21 with respect to relative displacement.

(application)
(1) As shown in FIG. 4, at least one lower part of a suspension spring or a damper with its axis directed up and down is attached to the front lower link 4. It is arranged so as to overlap with the link axis. In FIG. 4, the code | symbol 35 has illustrated the bush for attaching at least one lower part of a suspension spring or a damper to a front side lower link.

In general, in order to secure a large cargo space, it is effective to dispose the suspension spring and the lower attachment point of the damper not on the axle but on the lower link in the lower region.
As described above, since the distance between the two connect bushes 20 and 21 can be increased, it is possible to dispose a suspension spring and a damper with respect to the front lower link 4 within a limited link length. The degree increases. In addition, by disposing the suspension spring and the lower attachment point of the damper on the front lower link 4, it is possible to secure a cargo room of a predetermined size.

At this time, the reaction force from the suspension spring and the damper is input to the front lower link 4 and is not input to the two connect bushes 20 and 21 or the input is kept small. As a result, it is possible to use an elastic body of the connect bushes 20 and 21 having a low rigidity.
In addition, when a damper etc. are arrange | positioned at the rear side lower link 5 side provided with the overhang | projection part 7, reaction force of the direction which rotates the rear side lower link 5 seeing from a vehicle width direction is a damper depending on arrangement position. In some cases, the input to the two connect bushes 20 and 21 increases.

(2) In the above embodiment, the inner cylinder 9b of the first mounting bush 9 also serves as the wheel-side connect bush 20, but the inner cylinder of the first mounting bush 9 and the inner cylinder of the wheel-side connect bush 20 May be separate. Whether the inner cylinder is integral or separate, the inner cylinder of the first mounting bush 9 and the inner cylinder of the wheel-side connect bush 20 are arranged coaxially by allowing the bolt 31 to penetrate the inner cylinder together. Is done.

Moreover, in the said embodiment, although the structure which contact | abutted the elastic body 20c of the wheel side connection bush 20 to one side wall part 30a like FIG. 2 is illustrated, the inner cylinder 9b is long in the vehicle front-back direction back. In the no-load state, the rigidity of the wheel-side connect bush 20 may be further lowered by bringing the elastic body 20c of the wheel-side connect bush 20 and the one side wall portion 30a into a non-contact state.
Moreover, although the structure which the elastic body 20c of the wheel side connection bush 20 and the elastic body 9c of the 1st attachment bush 9 contact | abut directly is illustrated in the said embodiment, the wheel side connection bush 20 and the 1st attachment bush are illustrated. 9, an annular third elastic body interposed at least between the outer cylinder portion 20 a of the wheel-side connect bush 20 and the outer cylinder 9 a of the first mounting bush 9 may be disposed.

(3) FIGS. 5 and 6 show another example of a co-fastening structure for coupling the first mounting bush 9 and the wheel-side connect bush 20.
In this example, the elastic body 9c of the first mounting bush 9 is extended rearward in the vehicle front-rear direction, and the elastic bodies of the first mounting bush 9 and the wheel-side connect bush 20 are integrated.
That is, as shown in FIG. 6, an annular concave portion 20d for fitting the outer cylindrical portion 20a is formed in the extended elastic body 9c, and the outer cylindrical portion 20a is fitted into the concave portion 20d. Assemble.
Even with such a configuration, it is possible to achieve the same effects as the above-described enhancement. Moreover, the elastic body 9c becomes one and leads to the reduction of the number of parts.

(4) In the above embodiment, the case where the upper link 8 is constituted by one bar-like link is illustrated, but there may be two or more, or another shape such as an A arm.
(5) Moreover, in the said embodiment, although the axis | shaft of the vehicle body side connection bush 21 is arrange | positioned so that it may face substantially the vehicle front-back direction, it is not limited to this. For example, the axis of the connect bush 21 may be arranged along the vehicle width direction or the link axis L1.

(6) Moreover, in the said embodiment, by providing the overhang | projection part 7 which protrudes in the vehicle front-back direction front side with respect to the rear side lower link 5, the connection part of the two lower links 4 and 5 is made into the front side lower link 4. FIG. Although it arrange | positions at the side, it is not limited to this.
An overhanging portion that protrudes rearward in the vehicle front-rear direction with respect to the front lower link 4 may be provided, and the connecting portion of the two lower links 4 and 5 may be disposed on the rear lower link 5 side in a top view. Even in this case, the wheel-side connect bush may be fastened together with the attachment bush 10 that is a connecting portion of the rear lower link 5 to the axle 2.

(7) The connect bushing that constitutes the elastic connecting portion of the two lower links 4 and 5 is not limited to two locations, and may be three or more locations.
(8) In the above embodiment, the lower links 4 and 5 are exemplified as the two links arranged in the vehicle front-rear direction, but the two links may be an upper link or other links.
(9) Although the rear wheel suspension device is illustrated as the suspension device, the suspension device to which the present invention is applied may be a front wheel suspension device.

It is a top view which shows the suspension apparatus for rear wheels which concerns on embodiment based on this invention. It is a top view which shows the attachment structure of a wheel side connection bush. It is the exploded view which shows the attachment structure of a wheel side connection bush. It is a top view explaining attachment positions, such as a damper. It is a top view which shows another attachment structure of a wheel side connection bush. It is the exploded view which shows another attachment structure of a wheel side connection bush.

Explanation of symbols

1 wheel 2 axle (wheel support member)
3 Suspension member (vehicle body side member)
4 Front Lower Link 5 Rear Lower Link 6 Link Body 7 Overhang 7a Overhang Front End 8 Upper Link 9 First Mounting Bush 9a Outer Cylinder 9b Inner Cylinder 9c Elastic Body 20 Wheel Side Connect Bush 20a Outer Cylinder (Outside Tube)
20c Connect side elastic body 20d Recess 20e Protrusion 20f Elastic body portion 21 Car body side connect bush 30 Bracket 30a Side wall 31 Bolt

Claims (5)

A suspension device in which a first link and a second link, which are two links connecting a wheel support member that rotatably supports a wheel and a vehicle body side member, are arranged side by side in the vehicle longitudinal direction,
1 or 2 or more elastic connection parts which connect the 1st link and the 2nd link so that rocking is possible, and one of the 1 or 2 or more elastic connection parts is to the wheel support member of the 2nd link. The suspension device is connected to the second link through a connecting portion.   2. The suspension device according to claim 1, wherein the first link includes an overhang portion that projects toward the second link, and the overhang portion and the second link are connected by the elastic connection portion. .   The suspension device according to claim 2, wherein a lower part of at least one of a suspension spring and a damper is attached to the second link. In the suspension device in which the wheel side end of the second link is connected to the wheel support member via the bush,
The elastic coupling part is composed of a bush,
When the bush of the second link is referred to as a mounting bush, and the bush constituting the elastic connecting portion is referred to as a connect bush,
The suspension device according to any one of claims 1 to 3, wherein the attachment bush and the connection bush are coupled together by fastening. The bush is configured such that an elastic body is interposed between an inner cylinder and an outer cylinder arranged in a nested manner,
The inner cylinder of the mounting bush and the inner cylinder of the connect bush are arranged coaxially, and an elastic body is interposed between the outer cylinder of the mounting bush and the outer cylinder of the connect bush. Suspension device.

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