JP7103022B2 - Suspension structure - Google Patents

Description

The present invention relates to a suspension structure.

Generally, an independent suspension type suspension structure is known as a vehicle suspension structure, and a multi-link type suspension structure is further known as a kind of independent suspension type suspension structure. In the multi-link suspension structure, the knuckle is supported by the vehicle body by a plurality of arms, and the wheels are held by the knuckle. These plurality of arms are set so that the wheels move appropriately with respect to the input (toe-in, toe-out, etc.).

As such a multi-link suspension structure, one provided with a watt link has been proposed (see, for example, Patent Document 1). In the suspension structure described in Patent Document 1, the suspension member that supports the wheel hub by a plurality of arms has an elastic bush having high rigidity in the lateral direction and a watt link that rotates in the axial direction in the front-rear direction. It is attached to the car body via. As a result, the suspension member is easily moved by the force in the vertical direction or the front-rear direction, and is difficult to move by the force in the lateral direction, so that the riding comfort and the steering response are improved.

Japanese Unexamined Patent Publication No. 7-132720

However, in the suspension structure described in Patent Document 1, although the operation of the suspension member is limited, the camber angle of the support of the wheel hub itself may change depending on the vertical movement due to the arm arrangement. When the camber angle changes, the contact area between the tire and the road surface fluctuates, making it difficult to keep the tire grip constant. On the other hand, for example, if the wheel hub is simply made difficult to operate with respect to the input to the wheel by using a stiff bush, it becomes difficult to change not only the camber angle but also the toe angle, which may reduce the maneuvering performance of the vehicle. (That is, with a multi-link suspension, it was difficult to increase both the change in camber angle during bumping and the change in camber angle during rolling).

An object of the present invention is to provide a suspension structure capable of improving the maneuvering performance of a vehicle while suppressing fluctuations in tire grip.

The suspension structure of the present invention is a suspension structure including a pair of left and right knuckles that rotatably hold the wheels, and a cross member that extends along the vehicle width direction and connects the pair of knuckles to each other. The connection portion between the knuckle and the cross member defines a first rotation axis which is a rotation center of relative rotation between the knuckle and the cross member, and the first rotation axis extends in the vertical direction. It further comprises a watt link connected to the pair of knuckles, the watt link having a center link supported by the vehicle body between the pair of knuckles and each of the center link and the pair of knuckles. It has a pair of link arms to be connected, and the center link is supported by the vehicle body so as to be rotatable about a second rotation axis extending in a vertical direction.

According to the suspension structure of the present invention, it is possible to improve the maneuvering performance of the vehicle while suppressing the fluctuation of the tire grip.

It is a perspective view which shows the suspension structure which concerns on embodiment of this invention. It is a top view which shows the suspension structure. It is a rear view which shows the suspension structure. It is a side view which shows the suspension structure. It is a bottom view which shows the suspension structure. It is a top view which shows the state of the suspension structure when bumps are generated in both wheels. It is a rear view which shows the state of the suspension structure when bumps are generated in both wheels. It is a top view which shows the state of the suspension structure at the time of turning a vehicle. It is a rear view which shows the state of the suspension structure at the time of turning a vehicle. It is a perspective view which shows the suspension structure which concerns on the modification of this invention.

The invention according to claim 1 is a suspension structure including a pair of left and right knuckles that rotatably hold the wheels, and a cross member that extends along the vehicle width direction and connects the pair of knuckles. The connection portion between the knuckle and the cross member defines the first rotation axis which is the rotation center of the relative rotation between the knuckle and the cross member, and the first rotation axis extends in the vertical direction . Further equipped with a watt link connected to a pair of knuckles, the watt link includes a center link supported by the vehicle body between the pair of knuckles, a pair of link arms connecting the center link and each of the pair of knuckles, and a pair of link arms. The center link is a suspension structure characterized by being supported by a vehicle body so as to be rotatable about a second rotation axis extending in the vertical direction .

Since the connecting portion between the knuckle and the cross member can rotate relative to the first rotation axis along the vertical direction, the change in the toe angle is not easily hindered. Therefore, it is easy to intentionally change the toe angle with respect to the vertical movement of the tire, and the maneuvering performance of the vehicle can be improved. Further, since the first rotation axis is defined, the relative rotation around the rotation axis in the other direction is restricted, and the change in the camber angle is suppressed. Therefore, the contact area between the tire and the road surface is unlikely to change, and fluctuations in the tire grip can be suppressed.

Hereinafter, examples of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 5, the suspension structure 1 of this embodiment is a structure on the rear side of a front-wheel drive vehicle, and includes a pair of knuckles 2A and 2B, a cross member 3, and a watt link 4. Be prepared. The suspension structure 1 has a shape that is substantially symmetrical to the left and right. Hereinafter, the structure on the right side (knuckle 2A side) will be mainly described, and unless otherwise specified, the structure on the left side will be the same. do. The suspension structure of this embodiment may be adopted in a rear-wheel drive or four-wheel drive vehicle.

In this embodiment, the traveling direction of the vehicle is the X direction, the vehicle width direction is the Y direction, and the vertical direction is the Z direction. In the following, the front and back in the X direction are simply referred to as front and back, the central side in the Y direction is referred to as the inside, the left and right sides in the Y direction are referred to as the outside, and the top and bottom in the Z direction are simply referred to as up and down.

The knuckle 2A rotatably holds the wheels and has a hub 21 to which the wheels are mounted and a supported portion 22 arranged inside the hub 21 and supported by the vehicle body 10. The supported portion 22 has four arm portions 221 to 224 extending radially outward from the center of rotation of the wheel.

The arm portion 221 extending upward from the center of rotation of the wheel is supported by the vehicle body 10 by the I-shaped upper arm 51. The upper arm 51 extends from the arm portion 221 toward the front side. The arm portion 222 extending from the center of rotation of the wheel toward the front side and the upper side is supported by the vehicle body 10 by the A-shaped lower arm 52. The lower arm 52 includes an arm portion extending forward and inward from the arm portion 222, an arm portion extending inward, and a connecting portion extending in the front-rear direction to connect these two arm portions. The two arm portions are supported by the vehicle body 10, respectively.

The arm portion 223 extending upward from the center of rotation of the wheel and the arm portion 224 extending rearwardly and downwardly from the center of rotation of the wheel are connected to the cross member 3 as described later.

The cross member 3 is formed by connecting a first rod-shaped portion 31 extending linearly along the Y direction and a second rod-shaped portion 32 bent upward when viewed from the X direction at the central portion in the Y direction. Is. That is, the first rod-shaped portion 31 and the second rod-shaped portion 32 are fixed so as not to move relative to each other. Further, since the second rod-shaped portion 32 is bent, a recess 33 is formed on the lower side when the entire cross member 3 is viewed from the X direction. The first rod-shaped portion 31 and the second rod-shaped portion 32 have substantially the same dimensions in the Y direction, and the end portion of the first rod-shaped portion 31 and the end portion of the second rod-shaped portion 32 are in the Z direction. They are lined up.

Both ends of the first rod-shaped portion 31 are connected to the arm portions 223 of the knuckles 2A and 2B to form a connecting portion 61, and both ends of the second rod-shaped portion 32 are connected to the arm portions 224 of the knuckles 2A and 2B, respectively. The portion 62 is formed. The knuckles 2A and 2B and the cross member 3 are connected by two connecting portions 61 and 62, and the two connecting portions 61 and 62 are arranged in the Z direction. The first rotation shaft O1 along the Z direction is formed by the connecting portions 61 and 62, and the knuckles 2A and 2B and the cross member 3 are allowed to rotate relative to the first rotation shaft O1. Rotation around the axis of rotation in the direction is restricted.

The connection structure of the two connection portions 61 and 62 is arbitrary. For example, the ends of the rod-shaped portions 31 and 32 may be formed in a ball shape to form a connection structure that can operate three-dimensionally, or the ends of the rod-shaped portions 31 and 32 and the arm portion 223 may be connected to each other. One of them has a shaft portion extending along the Z direction and the other has a bearing portion so that the ends of the rod-shaped portions 31 and 32 can rotate in the Z direction (two-dimensionally movable). It may be axially supported.

The second rod-shaped portion 32 has an arm support portion 321 to which the link arms 42A and 42B described later of the watt link 4 are connected in the vicinity of the end portion thereof. The arm support portion 321 has a structure in which the ends of the link arms 42A and 42B are sandwiched and supported from the X direction.

The watt link 4 has a center link 41 and a pair of link arms 42A, 42B. The center link 41 is supported by the vehicle body 10 at the supported portion 411 so that it can rotate about the second rotation shaft O2 extending in the Z direction. Further, as shown in FIG. 2, the second rotation shaft O2 has the connection portions 61 and 62 of the knuckle 2A on the right side and the cross member 3 and the knuckle 2B and the cross member 3 on the left side when viewed from the Z direction. It is located at the center of the line segment (shown by the alternate long and short dash line) connecting the connecting portions 61 and 62.

The center link 41 has arm support portions 412A and 412B to which each of the pair of link arms 42A and 42B are connected, and the distances from the two arm support portions 412A and 412B to the supported portion 411 are substantially equal to each other. There is. The arm support portions 412A and 412B have a structure in which the ends of the link arms 42A and 42B are sandwiched and supported from the Z direction. Further, as shown in FIG. 3, the center link 41 is arranged between both ends of the second rod-shaped portion 32 when viewed from the X direction, that is, is arranged in the recess 33 of the cross member 3.

The link arms 42A and 42B extend in a rod shape while having a slight inclination with respect to the Y direction. The link arm 42A extending from the center link 41 to the right side is connected to the arm support portion 412A located on the rear side of the second rotation shaft O2, and the link arm 42B extending to the left side from the center link 41 is the second. It is connected to the arm support portion 412B located on the front side of the rotation shaft O2.

The inner ends of the link arms 42A and 42B are formed in a ball shape and are supported by arm support portions 412A and 412B so as to be able to operate three-dimensionally. The outer ends of the link arms 42A and 42B are formed in a ball shape and are supported by the arm support portion 321 so as to be able to operate three-dimensionally.

The center link 41 rotates clockwise when the arm support portion 321 of the cross member 3 approaches the second rotation axis O2 of the center link 41, and rotates counterclockwise when the center link 41 moves away from the center link 41. Here, the closeness between the arm support portion 321 and the center link 41 means a three-dimensional distance. Since the pair of arm support portions 412A and 412B are arranged so as to sandwich the second rotation shaft O2, when the right arm support portion 321 approaches (or moves away from) the second rotation shaft O2, the left side The arm support portion 321 of the above also approaches (or moves away from) the second rotation shaft O2.

That is, the distance from the right arm support portion 321 to the second rotation shaft O2 and the distance from the left arm support portion 321 to the second rotation shaft O2 are kept substantially equal to each other. As a result, it is restricted that the entire cross member 3 moves in parallel to the right side or the left side.

Here, the operation of each part of the suspension structure 1 when there is an input to the wheels will be described. In the following, the reference state is a state in which the vehicle is stopped on the horizontal plane (that is, gravity is mainly applied to the wheels due to the weight of the vehicle).

First, in the reference state, the lower arm 52 extends substantially parallel to the XY plane (see FIG. 4). When the knuckles 2A and 2B move from the reference state to either of the Z directions and the inclination angle (absolute value) of the lower arm 52 with respect to the Y direction becomes large, the front arms 221 and 222 of the knuckles 2A and 2B become large. , Pulled inward by the lower arm 52. Since the cross member 3 does not translate in the Y direction as described above, the rear arm portions 223 and 224 of the knuckles 2A and 2B hardly move in the Y direction. Therefore, only the front side of the knuckles 2A and 2B moves inward, and the toe angle of the wheels held by the knuckles 2A and 2B changes (toes in) to the inward side.

As a specific example of this, FIGS. 6 and 7 show the state of the suspension structure 1 when bumps are generated on both wheels. The knuckles 2A and 2B move upward with respect to the vehicle body 10 as compared with the reference state. At this time, the lower arm 52 is inclined with respect to the Y direction so that the outer end portion is located above the inner end portion. Similarly, the link arms 42A and 42B are also inclined with respect to the Y direction so that the outer end portion is located above the inner end portion.

At this time, the front sides of the knuckles 2A and 2B move inward as described above, and the wheels 20A and 20B toe in. Further, since the arm support portion 321 of the cross member 3 moves away from the second rotation shaft O2, the center link 41 rotates counterclockwise when viewed from above.

When the vehicle turns, a large force is applied to the outer wheel side of the turn, and the magnitude of the force applied to the left and right wheels is different. As a specific example, FIGS. 8 and 9 show the state of the suspension structure 1 when the vehicle turns (turns left) toward the left side. Since a large upward force is applied to the right wheel 20A on the turning outer ring side, the right knuckle 2A moves upward with respect to the vehicle body 10 as compared with the reference state. At this time, since the right arm support portion 321 moves away from the second rotation shaft O2, the center link 41 rotates counterclockwise when viewed from above. Due to the rotation of the center link 41, the left arm support portion 321 also tries to move away from the second rotation shaft O2. Since the force applied to the left wheel 20B is relatively small, the left arm support portion 321 moves downward. Therefore, the cross member 3 inclines upward to the right with respect to the Y direction.

In this specific example, as the right knuckle 2A moves upward, the lower arm 52 on the right side is tilted with respect to the Y direction so that the outer end is located above the inner end. .. As a result, the front side of the knuckle 2A moves inward, and the wheel 20A toe-in. Further, the connecting portions 61 and 62 allow the knuckles 2A and 2B and the cross member 3 to rotate relative to each other about the first rotation shaft O1, so that the knuckles 2A and 2B can rotate about the rotation shaft in the other direction. Due to the regulation, the camber angles of the wheels 20A and 20B hardly change. That is, the contact area between the tire and the road surface R hardly changes.

According to this embodiment, there are the following effects. That is, the connecting portions 61 and 62 of the knuckles 2A and 2B and the cross member 3 are capable of relative rotation of the knuckles 2A and 2B and the cross member 3 about the first rotation axis O1 along the Z direction. Therefore, it is difficult to prevent the change in toe angle. Therefore, it is easy to intentionally change the toe angle with respect to the vertical movement of the wheels, and the maneuvering performance of the vehicle can be improved. Further, the connecting portions 61 and 62 of the knuckles 2A and 2B and the cross member 3 regulate the relative rotation around the rotation axis in the other direction, so that the change in the camber angle is suppressed. Therefore, the contact area between the tire and the road surface R is unlikely to change, and fluctuations in the tire grip can be suppressed.

Further, by connecting the watt link 4 to the pair of knuckles 2A and 2B, it is possible to suppress the roll of the suspension while suppressing the toe angle from changing outside the setting. Further, in the watt link 4, the second rotation axis O2 of the center link 41 extends along the Z direction, so that the followability of the suspension in the Z direction is suppressed from being lowered, and the watt link 4 is saved in space. Can be placed with.

Further, the second rotation shaft O2 of the center link 41 is located at the center of the line segment connecting the connecting portions 61 and 62 on both sides in the Y direction, so that the second rotation shaft O2 is used as the roll center. Can be done. Further, the lengths of the left and right link arms 42A and 42B can be made substantially equal, and it is easy to suppress lateral displacement of the suspension.

Further, since the center link 41 is arranged in the recess 33 of the cross member 3, the watt link 4 can be arranged in a small space. Further, the cross member 3 has a second rod-shaped portion 32 bent when viewed from the X direction, and the link arms 42A and 42B are connected to the second rod-shaped portion 32, so that Y generated when the vehicle turns. The strength of the cross member 3 can be improved with respect to the force in the direction.

The present invention is not limited to the above-described embodiment, but includes other configurations and the like that can achieve the object of the present invention, and the following modifications and the like are also included in the present invention.

For example, in the above embodiment, it is assumed that the A-shaped lower arm 52 is connected to the arm portions 222 of the knuckles 2A and 2B, but the lower arm may have another shape. As in the suspension structure 1B of the modified example shown in FIG. 10, the L-shaped lower arm 53 may be connected to the arm portion 222. The lower arm 53 has an arm portion extending along the X direction and an arm portion extending along the Y direction, and the two arm portions are not connected and can be deformed independently. .. Further, the arms of each part may have an appropriate shape and length.

Further, in the above embodiment, the cross member 3 has a recess 33 on the lower side, but a recess may be formed on the upper side and a center link may be arranged in the recess. Further, the recess of the cross member is not limited to that formed by the bent rod-shaped portion. For example, the entire cross member may be formed in a plate shape, and a recess may be formed on the upper side or the lower side thereof. Further, the installation height of the center link may be shifted with respect to the cross member, and in this case, it is not necessary to form a recess in the cross member. Further, an opening may be formed in the cross member, and a center link may be arranged in the opening.

Further, the upper arm 51 as a link arm may function as follows. The upper arm 51 extends from the arm portions 221 of the knuckles 2A and 2B toward the front side, and the front end thereof is supported by the vehicle body 10. As a result, when the front side of the knuckles 2A and 2B is pulled inward by the lower arm 52 and the wheel toe-in as described above, the upper arm 51 is less likely to interfere with the toe-in operation and is in the front-rear position of the wheel. Work to determine.

Further, in the above embodiment, the second rotation shaft O2 of the center link 41 is located at the center of the line segment connecting the connecting portions 61 and 62 on both sides in the Y direction, but the second rotation shaft O2 The position may be arranged at an appropriate position according to the suspension setting, may be arranged in front of or behind the line segment connecting the connecting portions, or may be arranged shifted to the left or right from the central portion. good.

Further, in the above embodiment, the watt link 4 is connected to the pair of knuckles 2A and 2B, but for example, the movement of the cross member in the Y direction is restricted by another arm, and the movement is linear in the Z direction. If possible, the watt link may be omitted.

Further, in the above embodiment, two connecting portions 61 and 62 arranged in the Z direction are formed between the knuckles 2A and 2B and the cross member 3, thereby defining the first rotation shaft O1. , Not limited to such a configuration. For example, the first rotation shaft O1 may be defined by three or more connecting portions arranged in the Z direction, or the first rotation shaft O1 may be defined by the connecting portions extending along the Z direction.

In addition, the best configuration, method, and the like for carrying out the present invention are disclosed in the above description, but the present invention is not limited thereto. That is, the present invention is mainly illustrated and described with respect to specific embodiments, but without departing from the scope of the technical idea and purpose of the present invention, the shape with respect to the above-described embodiments. , Materials, quantities, and other detailed configurations can be modified by those skilled in the art. Therefore, the description that limits the shape, material, etc. disclosed above is merely an example for facilitating the understanding of the present invention, and does not limit the present invention. Therefore, those shapes, materials, etc. The description by the name of the member excluding a part or all of the limitation such as is included in the present invention.

1 Suspension structure 2A, 2B Knuckle 3 Cross member 33 Recess 4 Watt link 41 Center link 42A, 42B Link arm 61, 62 Connection part 10 Body

Claims (3)

A suspension structure including a pair of left and right knuckles that rotatably hold the wheels and a cross member that extends along the vehicle width direction and connects the pair of knuckles to each other.
The connection portion between the knuckle and the cross member defines a first rotation axis which is a rotation center of relative rotation between the knuckle and the cross member.
The first rotation shaft extends in the vertical direction and extends .
Further equipped with a watt link connected to the pair of knuckles
The watt link has a center link supported by the vehicle body between the pair of knuckles and a pair of link arms connecting the center link and each of the pair of knuckles.
The center link is a suspension structure characterized in that it is supported by the vehicle body so as to be rotatable about a second rotation axis extending in the vertical direction. The suspension structure according to claim 1 , wherein the second rotating shaft is located at the center of a line segment connecting the left and right connecting portions in a top view. The cross member has a recess on the upper side or the lower side when viewed in the front-rear direction.
The suspension structure according to claim 1 or 2 , wherein the center link is arranged in the recess.

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