JP4935557B2 - Suspension device - Google Patents

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 problems, the present invention provides two links for connecting a wheel support member and a vehicle body side member arranged side by side in the vehicle front-rear direction, and providing a connecting body between the two links. The connecting body and each link are individually and elastically connected to each other so as to be relatively displaceable within a predetermined range at least in the vehicle width direction and the vehicle vertical direction . The link and each link are connected via individual bushes, and the individual bushes connecting the links and the link are individually arranged at two or more locations separated in the vehicle width direction. Consists of two or more bushes.

  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)
Two lower links 4 and 5 that connect the lower region of the axle 2 that rotatably supports the wheel 1 and the suspension member 3 that is a vehicle body side member, and the upper region of the axle 2 and the suspension member 3 are connected. The upper link 8 is provided.

  The wheel side end portions of the two lower links 4 and 5 are attached to the axle 2 by a single bushing 9 and 10 so as to be vertically swingable, and the vehicle body side end portions are also respectively connected to the suspension member 3. The bushes 11 and 12 are connected in a vertically swingable state. 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 vehicle front-rear direction at a predetermined interval. Here, when the two lower links 4 and 5 are described separately, the lower link 4 on the front side in the vehicle longitudinal direction is the front lower link 4 and the lower link 5 on the rear side in the vehicle longitudinal direction is the rear lower link. Let's call it 5.
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 this 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 two lower links 4 and 5 are rod-like members extending linearly along the link axis lines L1 and L2, respectively, and the bushes 9 to 12 having the above-described configuration are provided on the both end mounting portions.
Further, when viewed from above, the connecting plate 6 is disposed between the two lower links 4 and 5. The connecting plate 6 is individually and elastically connected to the lower links 4 and 5.

  That is, the front side of the connecting plate 6 and the front lower link 4 are elastically connected via the two bushes 20 and 21 arranged offset in the vehicle width direction, and the rear portion of the connecting plate 6 The side and rear lower links 5 are also elastically connected via two bushes 22 and 23 arranged offset in the vehicle width direction. As a result, the relationship between the lower links 4 and 5 and the connecting plate 6 and the relationship between the lower links 4 and 5 are three-dimensionally swingably connected by the bushes 20 to 23 which are elastic connecting portions. At the same time, the amount of oscillation is also regulated by the span between the outer cylinder and the inner cylinder, the rigidity of the elastic body, and the like.

Here, the bushes 20 to 23 that individually and elastically connect the two lower links 4 and 5 and the connecting plate 6 are referred to as connect bushes 20 to 23, and the lower links 4 and 5, the axle 2, and the suspension are called. The bushes 9 to 12 that connect the member 3 are referred to as mounting bushes 9 to 12.
In the present embodiment, the connect bushes 20 to 23 that elastically connect the lower links 4 and 5 and the connecting plate 6 have the bush shafts oriented substantially in the vehicle front-rear direction. The connect bushes 20 to 23 are set to have low rigidity in the vehicle width direction by adopting an elastic body having lower rigidity than the elastic bodies of the mounting bushes 9 to 12.

Further, as shown in FIG. 2, the connect bushes 20 to 23 are formed by connecting the inner cylinders 20 b to 23 b in the elastic bodies 20 c to 23 c made of rubber interposed between the outer cylinders 20 a to 23 a and the inner cylinders 20 b to 23 b. The currants 20d to 23d (cavities) are formed above and below the sandwiched portion. Accordingly, when the connect bushes 20 to 23 are focused on the vertical deflection, the rigidity is low in the vertical deflection range until the currants 20d to 23d are crushed. In the vertical deflection deformation after the currants 20d to 23d are crushed, The rigidity is set high.
The bush is usually deformed linearly in proportion to the load up to a predetermined deformation region (elastic region) by a spring of an elastic body made of rubber, and is nonlinearly deformed (in an elastic-plastic region) when the threshold is exceeded. .

  Further, in the present embodiment, in the top view, the span in the vehicle front-rear direction between the attachment points of the two lower links 4 and 5 to the suspension member 3 (hereinafter simply referred to as vehicle body attachment points P1 and P3). Also, the two lower links 4, 5 are arranged so that the span in the vehicle front-rear direction between the attachment points to the axle 2 (hereinafter simply referred to as wheel-side attachment points P2, P4) is shorter. Yes. That is, in the top view, the intersection P5 between the link axis lines L1 and L2 connecting the wheel side attachment points P2 and P4 and the vehicle body side attachment points P1 and P3 in the two lower links 4 and 5 is from the axle 2. Is also set to be outward in the vehicle width direction, that is, outward in the vehicle width direction from the wheel side attachment points P2 and P4 of the lower links 4 and 5. In the example of FIG. 1, the front lower link 4 is larger than the offset amount (substantially zero in FIG. 1) of the wheel side attachment point P4 with respect to the vehicle body side attachment point P3 in the rear lower link 5 with respect to the vehicle side attachment point P3. So that the offset amount of the wheel side attachment point P2 in the vehicle longitudinal direction rearward relative to the vehicle body side attachment point P1 is larger than the inclination of the link axis L2 of the rear lower link 5 in the vehicle longitudinal direction rearward in the top view. The inclination of the link axis L1 of the front lower link 4 to the rear in the vehicle front-rear direction is set large. By arranging in this manner, the shape connecting the four wheel side attachment points P2, P4 and the vehicle body side attachment points P1, P3 of the two lower links 4, 5 becomes a substantially trapezoidal shape in a top view. ing.

Further, as compared with the rear lower link 5, the front lower link 4 is set so that the wheel side attachment points P2, P4 with respect to the vehicle body side attachment points P1, P3 are largely offset rearward in the vehicle longitudinal direction. The intersection P5 of the two link axes L1 and L2 of the two lower links 4 and 5 is disposed behind the center of the wheel 1 (wheel center W / C) in the vehicle front-rear direction when viewed from above.
Here, the axle 2 constitutes a wheel support member, the suspension member 3 constitutes a vehicle body side member, the connect bushes 20 to 23 constitute an elastic coupling portion, and the coupling plate 6 constitutes a coupling body.

(Function and effect)
(1) By elastically connecting the two lower links 4 and 5 via the connecting plate 6, it is possible to receive the vehicle longitudinal direction input to the wheel 1 by the two lower links 4 and 5. Become. For this reason, in order to receive the vehicle longitudinal direction input, it is not necessary to provide another link for connecting the axle 2 and the suspension member 3.
(2) Even when the two lower links 4 and 5 are elastically connected to each other via the connecting plate 6 in this way, the elastic connecting portion between the lower links 4 and 5 and the connecting plate 6 is connected to the connect bush 20. -23 to be configured to be able to swing only within a predetermined swing range, so that the connecting portion constituted by the bush is at least a predetermined swing range in the vehicle width direction with respect to an input in the vehicle longitudinal direction to the wheel 1. Are connected in a swingable state.

  As a result, the elastic bodies of the connect bushes 20 to 23 constituting the connecting portion are deflected with respect to the front-rear direction input to the wheel 1 (front-rear input to the wheel center W / C) due to road surface irregularities. As shown in FIG. 4, the inner cylinder is slightly swung in the vehicle front-rear direction with respect to the outer cylinder, and is swung in the vehicle width direction so that the wheels of the two lower links 4 and 5 in a top view are obtained. The substantially trapezoidal shape connecting the four side attachment points P2, P4 and the vehicle body side attachment points P1, P3 changes, and the rigidity in the vehicle longitudinal direction of the axle 2 supported by the two connected lower links 4, 5 is changed. 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 to 23 do not swing any more if the elastic body is bent more than a predetermined amount, the connection bushes 20 to 23 are prevented from swinging more than necessary without providing another member.
Further, since the connection bushes 20 to 23 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 to 23, the vibration of the front-rear direction input is good. Further, even if the lower links 4 and 5 are designed to satisfy the strength, the rigidity in the front-rear direction is determined by the rigidity of the connect bushes 20 to 23, so that the degree of freedom in design can be increased.

(3) Here, as described above, the connection bushes 20 to 23 shake the displacement between the two lower links due to the longitudinal input to the wheel 1 (the longitudinal input to the wheel center W / C) in the vehicle width direction. In this embodiment, the connection bushes 20 and 21 connected to the front link and the connection bushes 22 and 23 connected to the rear link are connected to each other. 23 is configured to share the deformation and bear the deformation. Therefore, when the connecting plate 6 is rigidly connected to the front lower link 4 or the rear lower link 5, that is, the connect bushes 20 and 21 connected to the front lower link 4 or the connect bush connected to the rear lower link 5. Compared to the configuration in which only one of the 22 and 23 groups is provided, the deformation amount of each of the connect bushes 20 to 23 can be reduced to half.
Since the durability of the elastic body made of rubber is proportional to about the third power of the amount of flexure deformation, the bush durability is improved by suppressing the amount of deformation of the bushes 20 to 23 to about half, that is, the connect bush 20 The life of ~ 23 is improved.

(4) Also, since the connection bushes 20 to 23 are bent with respect to the longitudinal input to the wheel 1 in this way, the rigidity of the longitudinal input can be set low, so the two lower links 4 and 5 are connected to each other. 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, even if the rigidity of the connect bushes 20 to 23 is set low, the lateral rigidity of the axle 2 is set. 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.

(5) Further, by setting the rigidity of the connect bushes 20 to 23 to a predetermined low bending deformation range, the rigidity is positively lowered, so that the following operational effects can be applied to the vehicle longitudinal direction input to the wheels 1. Play.
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 force in the vertical direction is also input to a certain connect bush 20 to 23. At this time, since the vertical rigidity of the connect bushes 20 to 23 is set low as described above, the connect bushes 20 to 23 are positively bent to absorb the vibration input to the suspension.

  At this time, the vertical displacement between the two lower links 4 and 5 is absorbed and displaced by the connect bushes 20 to 23 in the vertical direction. In this embodiment, the front lower link 4 is absorbed. The connection bushes 20 and 21 connected to the rear lower link 5 and the connection bushes 22 and 23 connected to the rear lower link 5 are shared by the connection bushes 20 to 23 to bear the deformation. Therefore, when the connecting plate 6 is rigidly connected to the front lower link 4 or the rear lower link 5, that is, the connect bushes 20 and 21 connected to the front lower link 4 or the connect bush connected to the rear lower link 5. Compared with the configuration in which only one of the 22 and 23 groups is provided, the deformation amount of each of the connect bushes 20 to 23 can be reduced to about half. As a result, the deformation amount of each of the connect bushes 20 to 23 can be reduced to half.

  Since the durability of the elastic body made of rubber is proportional to the third power of the amount of repeated bending deformation, the bush durability is improved by suppressing the amount of deformation of the bush to about half, that is, the connection bushes 20-23. The service life is improved. Here, since there is a crushing margin due to the currants 20d to 23d in the vertical direction, for example, as a comparative example, the connecting bushes 20 and 21 are connected to the front lower link while the connecting plate 6 is rigidly connected to the rear lower link 5. Assuming a configuration that receives the above-described vertical swinging alone, in the comparative example, if the bush deformation amount is 6 mm in total, that is, the collapse amount 2 mm of the currants 20 d to 23 d + the linear deformation region 4 mm, as in this embodiment In the configuration in which both the connect bushes 22 and 23 connected to the rear lower link 5 and the connect bushes 20 and 21 connected to the front lower link 4 receive the above vertical swing, the amount of curling 20d to 23d is 2 mm + linear deformation. The deformation amount is 3 mm in total with an area of 1 mm, and the durability is further improved by the amount of currants 20d to 23d.

(6) In this way, the connect bushes 20 to 23 connecting the two lower links 4 and 5 can be set to two groups of the front connect bushes 20 and 21 and the rear connect bushes 22 and 23. As a result, the amount of bending deformation generated in each of the connect bushes 20 to 23 can be reduced as compared with the case where only one connect bush 20, 21, or 22, 23 group is used. As a result, the relative change between the two lower links 4 and 5 can be reduced. Can be increased by a factor of approximately two. As a result, the characteristic change can be set to a linear state in a wide load range.
(7) Also, the bush rigidity characteristics of the front-side connect bush 20 to 23 group and the rear-side connect bush 20 to 23 group may all be the same characteristic, or a part or all of them may be set to different characteristics. As a result, the degree of freedom of bush rigidity increases, so that the suspension characteristic setting range can be widened.

(8) Further, if the vertical rigidity of the connect bushes 20 to 23 to the predetermined threshold is positively lowered, the following effects can be obtained.
Since the two lower links 4 and 5 are offset downward from the wheel center in a side view, the vertical component is applied when inputting in the front-rear direction such as when overriding the protrusion as described above. Is also input. At this time, the vertical rigidity of the connect bushes 20 to 23 is set to be low, so that the connect bushes 20 to 23 are moved in the left-right direction (vehicle width direction or As a result of absorbing the vibration by swinging in the vertical direction (in the direction of the link axis L1 of the front lower link 4) and swinging in the vertical direction, as described above, the suspension vibration fits well with respect to the longitudinal input to the wheel. Furthermore, as a result of suppressing the vibration propagating to the passenger compartment side, the shock when riding over the protrusion is further reduced.

Here, with regard to the swinging of the connect bushes 20 to 23 when the protrusions are overtaken, the torsional displacement mainly occurs in the vertical direction of the connect bushes 20 to 23 on the wheel side, and both of them are subjected to shear. A swing displacement in the left-right direction is generated in the connect bushes 20 to 23 to absorb the vibration.
In addition, when a large swing displacement that causes the currants 20d to 23d to be crushed is input, the rigidity is increased, so that the swing amount is suppressed to a predetermined value or less.

(9) In addition, when viewed from above, the intersection P5 of the link axes L1 and L2 of the two lower links 4 and 5 connected to each other is attached to the wheel side outside the axle 2 in the vehicle width direction, that is, in the vehicle longitudinal direction. By setting the span between the points P2 and P4 to be narrower than the span between the vehicle body side attachment points P1 and P3, the following operational effects can be obtained.
When there is an input in the vehicle longitudinal direction rearward with respect to the wheel 1 due to braking or the like, the wheel side attachment points P2 and P4 of the two lower links 4 and 5 are both oscillated and displaced by substantially the same amount rearward in the vehicle longitudinal direction. However, a toe change in the toe-in direction is caused by the difference in vehicle lateral displacement of the wheel side attachment points P2 and P4 of the two lower links 4 and 5, and the stability during braking is improved.

  In the example of FIG. 1, the rear lower link 5 has a link axis L2 set substantially in the vehicle width direction, but the front lower link 4 has a link axis L1 in the vehicle longitudinal direction so that the wheel 1 side is rearward in the vehicle longitudinal direction. As a result of tilting backward in the front-rear direction, the wheel side attachment points P2, P4 of the two lower links 4, 5 both swing and displace by substantially the same amount rearward in the vehicle front-rear direction, but on the wheel side of the rear lower link 5 The wheel 1 changes in the toe-in direction when the wheel side attachment point P2 of the front lower link 4 is drawn to the vehicle side from the attachment point P4.

(10) Further, in the top view, the intersection P5 of the link axes L1 and L2 of the two lower links 4 and 5 is positioned rearward in the vehicle front-rear direction from the center of the wheel 1 (wheel center W / C). The rotation center of the axle 2 is located behind the wheel center W / C. For this reason, with respect to the input in the tire lateral direction at the time of turning of the vehicle, a torque for directing the wheel 1 on the turning outer wheel side in the toe-in direction works, and stability at the time of turning of the vehicle is improved.

(application)
(1) In the above embodiment, the case where the connecting plate 6 is directly connected to the lower links 4 and 5 via the elastic body is illustrated, but the present invention is not limited to this. It is also possible to provide an overhanging portion that projects from the lower links 4 and 5 toward the connecting plate 6 and to elastically connect the overhanging portion and the connecting plate 6 via a bush.
(2) Moreover, a connection body is not limited to the said connection plate 6, ie, plate shape, You may become frame shape and other shapes.
Moreover, the connection body may be divided | segmented into plurality. For example, the first connecting body for connecting the wheel-side connect bushes 20, 22 of the two lower links 4, 5 and the vehicle-side connect bushes 21, 23 of the two lower links 4, 5 are connected. You may comprise from two connection bodies of a 2nd connection body.

(3) In the above embodiment, the connecting plate 6 has a shape that fits between the two lower links 4 and 5 when viewed from above, but is not limited thereto. For example, the lower links 4 and 5 and the connecting plate 6 may be individually elastically connected in a state where the lower links 4 and 5 and a part of the connecting plate 6 face each other in the vertical direction. .
(4) Moreover, the connection bush which comprises the elastic connection part which connects each lower link 4 and 5 and the connection board 6 is not limited to two places, There may be three or more places.
(5) 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.

(6) In the above embodiment, the two lower links 4 are arranged by arranging the link axis L2 of the rear lower link 5 in the vehicle width direction and tilting the link axis L1 of the front lower link 4 rearward in the vehicle front-rear direction. Although the intersection point P5 of the five link axis lines L1 and L2 is set to be outward in the vehicle width direction from the axle 2, it is not limited to this. For example, the link axis L1 of the front lower link 4 is arranged substantially in the vehicle width direction and the link axis L2 of the rear lower link 5 is arranged such that the wheel side attachment point P4 is closer to the front side in the vehicle longitudinal direction than the vehicle body side attachment point P3. In addition, the intersection P5 of the link axes L1 and L2 of the two lower links 4 and 5 may be set to be more outward in the vehicle width direction than the axle 2 by inclining to the front side.

(7) Moreover, in the said embodiment, although the axis | shafts of the connect bushes 20-23 are arrange | positioned so that it may face substantially vehicle front-back direction, it is not limited to this. For example, the shafts of the connect bushes 20 to 23 may be arranged along the vehicle width direction or the link axis lines L1 and L2.
(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.
Further, 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 sectional drawing which shows the connect bush based on this invention. It is a top view which shows the behavior with respect to the input to a vehicle front-back direction.

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 Connecting Plate 8 Upper Link 20-23 Connect Bush 20-23
20c-20c elastic body 20d-23d currant

Claims (4)

In the suspension device in which the two links that connect the wheel support member that rotatably supports the wheel and the vehicle body side member are arranged side by side in the vehicle front-rear direction,
With a connector,
The link and each link are connected via individual bushes, and the individual bushes connecting the links and the link are individually arranged at two or more locations separated in the vehicle width direction. A suspension device characterized by comprising a bush to elastically connect the connecting body and each link in such a manner that they can be relatively displaced at least within a predetermined range in the vehicle width direction and the vehicle vertical direction . The bush, for bending deformation in the vertical direction, the suspension device according to claim 1 until a predetermined bending deformation low rigidity, characterized in that the relatively rigid exceeds the predetermined bending deformation increases . In the top view, the intersection of the link axes connecting the attachment points to the respective wheel support members and the attachment points to the vehicle body side members of the two links is greater than the attachment points of the links to the wheel support members. suspension device according to claim 1 or claim 2, characterized in that it positioned outward in the width direction. In the top view, the intersection of the link axes connecting the attachment points to the respective wheel support members and the attachment points to the vehicle body side members in the two links is located rearward in the vehicle longitudinal direction from the center of the wheels. The suspension device according to any one of claims 1 to 3 , wherein:

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