JP7562095B2 - Suspension arms - Google Patents

Description

The present invention relates to a suspension arm.

Suspension devices that independently suspend the left and right wheels of an automobile are widely used. Such suspension devices include suspension arms that support the wheels so that they can swing up and down, and springs and shock absorbers that absorb the load input from the wheels. When the automobile travels over an uneven road surface, the suspension device absorbs the shock, allowing the passengers to ride in comfort.

In a suspension device like the one described above, if the wheel swings significantly above the vehicle body, it can cause damage to the suspension device. To prevent such excessive swinging, a component called a bump stopper is provided on the suspension arm or the vehicle frame.

For example, Patent Document 1 describes a lower arm that is composed of an upper member and a lower member, and that has a bump stopper provided at a predetermined position on the upper member. The lower arm is hollow, and has a first reinforcement and a second reinforcement built in at the position of the bump stopper.

Patent No. 4396854

In the lower arm of Patent Document 1, a first reinforcement and a second reinforcement are provided to reinforce the lower arm against the load input from a member called a bump stopper. When the lower arm swings up and down due to the load input from the wheel, the bump stopper abuts against the chassis frame, suppressing the impact while restricting the swinging of the lower arm. In the lower arm of Patent Document 1, the reinforcing member is composed of two members, so the work of assembling the reinforcing member to the lower arm is complicated.

In addition, a configuration is known in which the end of a shock absorber is fixed to a suspension arm in a swingable state. The shock absorber regulates the expansion and contraction of the coil spring. Since a load is input from the shock absorber to the suspension arm, a reinforcing member is provided at the position where the shock absorber is fixed to the suspension arm.

If both the reinforcing member for the bump stopper and the reinforcing member for the shock absorber are mounted on the suspension arm, the weight of the suspension arm increases, the structure of the suspension arm becomes complicated, and the manufacturing process becomes cumbersome.

The present invention aims to provide a suspension arm in which a reinforcing member for resisting loads input from members that regulate the swing of the suspension arm, such as bump stoppers, is constructed from fewer parts, and the reinforcing member functions to reinforce both the loads input from members that regulate the swing of the suspension arm and the loads input from shock absorbers.

The above problem is solved by a suspension arm having one end connected to a wheel support member and the other end connected to a vehicle body, the suspension arm having a hollow shape with a plate-shaped upper member having a shock absorber mounting portion and a plate-shaped lower member, the suspension arm having a reinforcing member disposed between the upper member and the lower member, the reinforcing member having a shape with a plate-shaped first receiving portion extending along the extension direction of the suspension arm, a pair of plate-shaped wall portions extending from an end of the first receiving portion in the vertical direction of the vehicle body, and a pair of plate-shaped second receiving portions extending from an end of the wall portions along the extension direction of the suspension arm, the second receiving portions contacting the inner surface of the lower member, the wall portions having a shape extending in the extension direction of the suspension arm so as to overlap the shock absorber mounting portion, and the first receiving portion being disposed so that a regulating portion that regulates the swing of the suspension arm contacts the inner surface of a portion where the upper member is in contact.

In the above suspension arm, the reinforcing member has a second receiving portion that extends along the extension direction of the suspension arm. The second receiving portion is configured to contact the inner surface of the inner surface of the lower member. In this configuration, the wall portion of the reinforcing member contacts the inner surface of the lower member via the second receiving portion, so no separate reinforcing member such as the above-mentioned first reinforcement is required. In addition, the wall portion of the reinforcing member is shaped to extend in the extension direction of the suspension arm so as to overlap the mounting portion of the shock absorber. Therefore, the reinforcing member can support and reinforce not only the load input from the bump stopper, but also the load input from the shock absorber. With this configuration, the suspension arm can be reinforced against the load input from the bump stopper and the load input from the shock absorber with a smaller number of parts.

In the above suspension arm, it is preferable that the upper surface of the upper member is shaped to have an inclined portion so that a height difference is created in the amount of protrusion from the bottom surface of the lower member. By forming a height difference in the upper member, the rigidity of the surface of the upper member can be improved. This makes it less likely to break when a load is input to the upper member from a bump stopper or shock absorber.

In the above suspension arm, it is preferable that the first receiving portion is in contact with the upper portion formed by the inclined portion, and the tip portion of the wall portion in the suspension arm extension direction is in contact with the lower portion formed by the inclined portion. In this configuration, the reinforcing member is in contact with the upper member at both the upper portion and the lower portion, so that the load input from the bump stopper or shock absorber can be efficiently transmitted to the reinforcing member and supported by the reinforcing member.

In the above suspension arm, it is preferable that the wall portion is cut out so that the height from the bottom surface of the second receiving portion at the end opposite the second receiving portion, which does not have the first receiving portion, is smaller than the height at the point where the first receiving portion is provided. With this configuration, the weight of the reinforcing member can be reduced, thereby achieving weight reduction.

The present invention makes it possible to provide a suspension arm in which a reinforcing member for resisting loads input from members that regulate the swing of the suspension arm, such as bump stoppers, is constructed from fewer parts, and the reinforcing member functions to reinforce both the loads input from members that regulate the swing of the suspension arm and the loads input from shock absorbers.

FIG. 1 is a diagram showing an embodiment of a suspension device including a suspension arm according to the present invention, and is a diagram showing the suspension device as viewed from the rear of a vehicle body. FIG. 2 is an exploded perspective view of a lower arm constituting the suspension device of FIG. 1 . FIG. 3 is a plan view of the lower arm of FIG. 2 . FIG. 3 is a perspective view showing a reinforcing member built into the lower arm of FIG. 2 . FIG. 4 is a cross-sectional view taken along line AA in FIG. 3 . FIG. 4 is a cross-sectional view taken along line BB in FIG. 3 . 1 is a plan view showing a pattern for cutting an original sheet of a reinforcing member from a metal plate. FIG.

Below, an embodiment of the present invention will be described with reference to the drawings. The suspension arm described below is merely one example of an embodiment of the present invention.

In this embodiment, a reinforcing member is built into the lower arm, which is one component of the suspension device shown in Figure 1. The suspension device 9 shown in Figure 1 is a double wishbone type suspension device. The device 9 has an upper arm 1, a lower arm 2, a wheel support member 3, a shock absorber 4, a coil spring 5 attached to the outer periphery of the shock absorber 4, and a restricting portion 6 that restricts excessive swing of the suspension arm.

As shown in FIG. 2, the lower arm 2 is constructed by overlapping the side edge of a plate-shaped upper member 21 with the side edge of a plate-shaped lower member 22 and fixing the overlapped portion by welding. The lower arm 2 has a hollow shape. The side edge of the upper member 21 or the side edge of the lower member 22 has a shape in which the end of a metal plate is bent upward or downward from the vehicle body. Like the lower arm 2, the upper arm 1 is also constructed by welding the overlapped portion of the side edge of the plate-shaped upper member 11 with the side edge of the plate-shaped lower member 12.

As shown in FIG. 1, one end of the lower arm 2 has an attachment portion 23 for the wheel support member 3. The other end of the lower arm 2 has an attachment portion 24 for the vehicle body. Similarly, the upper arm 1 has an attachment portion 13 for the wheel support member 3 and an attachment portion 14 for the vehicle body.

As shown in Figs. 2 and 3, the lower arm 2 is substantially triangular in plan view and bottom view, and includes a first arm portion 25 extending between an attachment portion 23 for the wheel support member 3 and an attachment portion 24 for the vehicle body, and a second arm portion 26 extending between the attachment portion 23 for the wheel support member 3 and the attachment portion 24 for the vehicle body. A wide portion 27 having a predetermined area is disposed in the middle of the lower arm 2. The wide portion 27 has a width larger than the width of the first arm portion 25 or the width of the second arm portion 26. A bracket 41 that supports the end of the shock absorber 4 is provided on the wide portion 27 as an attachment portion of the shock absorber 4. The first arm portion 25 and the second arm portion 26 described above are shaped like hollow arms protruding toward the other end in plan view and bottom view, and are shaped to have a smaller width than the wide portion 27 described above, and are shaped to communicate with the hollow wide portion 27.

The mounting portion 24 for the vehicle body described above is composed of a hollow tubular member arranged so that its axial direction coincides with the front-rear direction of the vehicle body. A rubber bushing is built into the inside of the tubular member. By inserting the shaft on the vehicle body side into the rubber bushing, the lower arm 2 is supported on the vehicle body in a state in which it can swing in the up-down direction of the vehicle body. The tubular member is fixed by welding to the end of the first arm portion 25 and the end of the second arm portion 26.

As shown in FIG. 1, an attachment member 23 for the wheel support member 3 is fixed to one end of the lower arm 2. The attachment member 23 is composed of a ball joint having a case for receiving a ball, a ball stored in a slidable state relative to the case, and a rod connected to the ball. One end of the lower arm 2 is provided with a plurality of through holes for fixing the ball joint. The ball joint may be fixed to the lower arm by welding.

The upper arm 1 is constructed in the same manner as the lower arm 2. An attachment member 13 for the wheel support member 3 is fixed to one end of the upper arm 1. As shown in FIG. 1, the attachment member 13 is composed of a ball joint having a case that receives a ball, a ball that is stored in a slidable state relative to the case, and a rod to which the ball is connected. One end of the upper arm 1 is provided with multiple through holes for fixing the ball joint. In the lower arm, the rod portion of the ball joint protrudes downward. In the upper arm, the rod portion of the ball joint protrudes upward, which is a difference.

As shown in Figures 3 and 6, an inclined portion 211 is formed in the upper member 21 constituting the lower arm 2. The inclined portion 211 is a boundary between an upper portion 212 provided toward the rear of the vehicle body and a lower portion 213 provided toward the front of the vehicle body, and has a shape that extends in the vehicle width direction. The upper portion 212 is shaped so that the amount of protrusion of the upper portion 212 based on the bottom surface of the lower member 22 constituting the lower arm is greater than the amount of protrusion of the lower portion 213.

As shown by the two-dot chain circle in FIG. 3, the upper portion 212 of the upper member 21 constituting the lower arm 2 near the rear of the vehicle body is the portion that abuts against the restricting portion 6 that restricts excessive swinging of the lower arm 2. This portion is provided at the base of the second arm portion 26. Since an inclined portion 211 is provided adjacent to the portion that abuts against the restricting portion 6, when a load from the restricting portion 6 is input to the upper member 21, the surface of the upper member 21 is less likely to deform or break.

As shown in FIG. 3, the wide portion 27 of the upper member 21 constituting the lower arm 2 is provided with a bracket 41 for fixing the lower end of the shock absorber 4. The bracket 41 is provided in the middle of the vehicle body in the front-rear direction, and is provided on the lower portion 213 described above. The bracket 41 is composed of a plate-shaped first wall 41a arranged toward the front of the vehicle body and a plate-shaped second wall 41b arranged toward the rear of the vehicle body. The first wall 41a and the second wall 41b extend in the vehicle width direction and have a shape that extends upward from the part connected to the upper member as a base end. The first wall 41a and the second wall 41b each have a through hole. A shaft for supporting the lower end of the shock absorber 4 is inserted and fixed in the through hole.

As shown in FIG. 1, the upper arm 1 differs in that the portion corresponding to the wide portion of the lower arm 2 is a space for passing the shock absorber 4 and the coil spring 5 attached thereto. The space is located between the first arm portion and the second arm portion of the upper arm 1. The first arm portion is located toward the front of the vehicle body, and the second arm portion is located toward the rear of the vehicle body.

As shown in FIG. 1, the wheel support member 3 has a ball joint mounting portion 31 that extends inward in the vehicle width direction, and a connecting portion 32 that connects the upper and lower mounting portions 31. A support portion for supporting the wheel is disposed in the middle of the connecting portion 32. Examples of the wheel support member include parts such as knuckles. Examples of the wheel support portion include parts such as hubs.

As shown in Figure 1, the ball joint on the lower arm side has a rod that protrudes downward toward the vehicle body. The tip of the rod is connected to the upper surface of the ball joint's mounting part 31. The ball joint on the upper arm side has a rod that protrudes upward toward the vehicle body. The rod is connected to the lower surface of the ball joint's mounting part 31.

5 and 6, a reinforcing member 7 is disposed between the upper member 21 and the lower member 22 that constitute the lower member 22. The reinforcing member 7 has a shape including a plate-shaped first receiving portion 71 extending along the extension direction of the suspension arm (lower arm 2), a pair of plate-shaped wall portions 72 extending from the end of the first receiving portion 71 in the vertical direction of the vehicle body, and a pair of plate-shaped second receiving portions 73 extending from the end of the wall portions 72 along the extension direction of the suspension arm. As shown in FIG. 4, the reinforcing member 7 has a so-called hat-shaped cross section. The end of the wall portion 72 in the extension direction of the suspension arm (lower arm 2) is cut out at the end opposite to the second receiving portion 73, leaving the first receiving portion 71 at the base end. The extension direction of the suspension arm refers to the direction in which the plate material of the upper member or the plate material of the lower member that constitutes the suspension arm extends. Therefore, the extension direction of the suspension arm includes not only the direction in which the first arm portion 25 or the second arm portion 25 extends, but also a direction perpendicular to the direction in which the first arm portion 25 or the second arm portion 25 extends.

The first receiving portion or the second receiving portion is preferably shaped to fit the inner surface of the upper member or the lower member to which it is connected. In the lower arm 2 of this embodiment, the first receiving portion 71 and the second receiving portion 73 are both plate-shaped with flat surfaces. The first receiving portion 71 may be provided with, for example, a circular through hole.

As shown in FIG. 4, due to the above-mentioned cutout, at the tip portion of the reinforcing member 7, the height of the wall portion 72 based on the bottom surface of the second receiving portion 73 is smaller than the height of the wall portion 72 at the base end portion where the first receiving portion 71 is provided. This cutout reduces the amount of material that constitutes the reinforcing member 7, thereby reducing the weight and cost of the suspension device. In addition, by forming a shape with a cutout in the reinforcing member 7, as shown in FIG. 6, an inclined portion 74 is formed in the reinforcing member 7, so that the inclined portion 211 and the reinforcing member 7 do not interfere with each other.

When manufacturing the above-mentioned reinforcing member 7 from a metal plate as a raw material, a mold is made as shown in FIG. 7. In this specification, the planar state of the reinforcing member 7 before it is formed into a three-dimensional shape by bending or press molding is called the original plate. The original plate 8 has a base 81 extending in the left-right direction and protruding portions 82 protruding from both ends of the base 81. A recess 84 is formed between the pair of protruding portions 82.

When making the mold, it is preferable to fit one of the protrusions 82 of one original plate 8 between the recesses 84 of the other original plate 8, as shown in FIG. 7. This reduces the weight of the reinforcing member 7 and also reduces the amount of scrap material generated when cutting the original plate 8 from the metal plate 85, improving yield.

In the suspension device 9 of this embodiment, as shown in FIG. 1, the regulating portion 6 is composed of a cushioning material 61 made of rubber material fixed to a side frame of the vehicle body, and a mounting portion 62 that fixes the cushioning material. The mounting portion 62 is fixed to a side frame 63 of the vehicle body, and is arranged so that the cushioning material 61 is located above the upper member 21 that constitutes the lower arm 2. As shown in FIG. 1, when the lower arm 2 of the suspension device 9 is not swinging, the cushioning material 61 and the upper member 21 are separated from each other. When the lower arm 2 swings excessively, the upper member 21 and the cushioning material 61 come into contact with each other, preventing the suspension device including the lower arm 2 from swinging excessively and interfering with other members.

In the suspension device 9 of this embodiment, the reinforcing member 7 is fixed to the lower arm 2 with the first receiving portion 71 of the reinforcing member 7 contacting the inner surface of the upper member 21 constituting the lower arm 2. The first receiving portion 71 is disposed inside the portion where the restricting portion 6, which restricts excessive swinging of the lower arm 2, contacts the upper member 21. As described above, this portion is indicated by a two-dot chain circle in FIG. 3. The reinforcing member 7 is fixed to the lower arm 2 with a pair of second receiving portions 73 provided on the reinforcing member 7 contacting the inner surface of the lower member 22. Furthermore, the reinforcing member 7 is fixed to the lower member 22 with the tip end portion of the wall portion 72 located on the opposite side of the second receiving portion 73 contacting the inner surface of the upper member 21. The tip portion is located at the tip of the wall portion 72 in the extension direction of the suspension arm. As shown in Figures 2 and 3, the wall portion 72 of the reinforcing member 7 is shaped to extend in the extension direction of the suspension arm so as to overlap the mounting portion of the bracket 41, which is the mounting portion of the shock absorber 4, in plan and bottom views.

As described above, the upper member 21 of the lower arm 2 is shaped to have a height difference between the upper portion 212 and the lower portion 213. The reinforcing member 7 is shaped to be placed in the space between the upper member 21 and the lower member 22, with the first receiving portion 71 of the reinforcing member 7 contacting the upper portion 212 of the upper member 21, the upper end of the tip portion of the wall portion 72 contacting the lower portion 213 of the upper member 21, and the second receiving portion 73 contacting the inner surface of the lower member 22. This allows the load input to the upper member 21 to be efficiently transmitted to the reinforcing member 7.

As shown in FIG. 6, an inclined portion 74 is disposed between the first receiving portion 71 of the reinforcing member 7 and the wall portion 72 disposed on the tip side. The inclined portion 74 of the reinforcing member 7 is configured to have a gentler inclination angle than the inclined portion 211 of the upper member 21. When the reinforcing member 7 is fixed to the upper member 21, the inclined portion 211 and the inclined portion 74 are configured not to interfere with each other. This configuration is less susceptible to the influence of errors during processing, and can improve the workability of assembly. The inclination angle of the inclined portion 74 of the reinforcing member 7 may be set to be equal to the inclination angle of the inclined portion 211 of the upper member 21, so that the inclined portion 211 and the inclined portion 74 are in contact with each other. In this way, the load can be transmitted more efficiently between the upper member and the lower member.

When the lower arm 2 swings excessively in the vertical direction of the vehicle body due to a load being input from the wheels, the above-mentioned restricting portion 6 comes into contact with the upper member 21 constituting the lower arm 2, restricting the excessive swing. At this time, the load input to the upper member 21 is distributed to the lower member 22 via the first receiving portion 71, wall portion 72, and second receiving portion 73 of the reinforcing member 7, and the load is supported by the entire lower arm 2. This prevents the lower arm 2 from being damaged by the load concentrating on one part of the lower arm 2.

When the lower arm 2 swings in the vertical direction of the vehicle body due to a load being input from the wheels, for example, a load is also input to the lower arm 2 from the mounting portion of the shock absorber 4. As described above, the reinforcing member 7 is shaped to extend in the extension direction of the suspension arm so that the wall portion 72 overlaps with the mounting portion of the shock absorber 4. Therefore, the load input from the shock absorber 4 is also distributed to the lower member 22 via the wall portion 72 and the second receiving portion 73, and the load is supported by the entire lower arm 2. This prevents the lower arm 2 from being damaged by the load concentrating on one part of the lower arm 2.

The reinforcing member 7 is configured such that the second receiving portion 73 contacts the inner surface of the lower member 22 with a surface. The load transmitted to the reinforcing member 7 is transmitted to the lower member 22 via the second receiving portion 73. This prevents the load from concentrating locally on the connection portion between the reinforcing member 7 and the lower member 22. By providing the second receiving portion 73, it is no longer necessary to provide multiple reinforcing members such as a first reinforcement and a second reinforcement as in conventional reinforcing members, and it is possible to reduce the number of reinforcing members used. This allows the suspension device to be made lighter and less expensive.

The reinforcing member 7 and the upper member 21 or the lower member 22 are preferably fixed by welding. In the suspension device 9 of this embodiment, the contact portion between the edge of the first receiving portion 71 and the upper member 21, the contact portion between the edge of the wall portion 72 and the upper member 21, and the contact portion between the edge of the second receiving portion 73 and the lower member 22 are each welded. As shown in FIG. 2, the lower member 22 has multiple through holes for welding.

The configuration of the regulating portion is not limited to that of the above embodiment. For example, the regulating portion may be configured by fixing a buffer material to an upper member constituting the lower arm, and providing a stopper such as a hollow tube on a vehicle body structure such as a side frame to contact the buffer material and regulate the rocking.

The configuration of the bracket supporting the shock absorber is not limited to that of the above embodiment. For example, the bracket may extend in a direction intersecting the first and second walls and have a third wall connecting one end of the first wall to one end of the second wall. The bracket may also extend in a direction intersecting the first and second walls and have a fourth wall connecting the other end of the first wall to the other end of the second wall. The configuration of the mounting part for mounting the shock absorber to the suspension arm is not limited to a bracket, and may be other configurations, such as a bearing provided on the suspension arm.

In the suspension arm 9 of the above embodiment, an inclined portion 211 is provided on the upper member 21. It is preferable that the height difference caused by the inclined portion 211 is provided on the surface on which the restricting portion 6 that limits the swing of the suspension arm or the mounting portion of the shock absorber 4 is provided. By doing so, it is possible to improve the surface strength of the suspension arm against the load input from the restricting portion or the shock absorber.

In the suspension arm of the above embodiment, as shown in FIG. 3, in plan view or bottom view, the pair of wall portions 72 that is closer to the inside of the vehicle body is shaped to extend in the extension direction of the suspension arm so as to overlap the bracket 41. At least a portion of the reinforcing member may be shaped to overlap the mounting portion of the shock absorber in plan view and bottom view. For example, both wall portions 72 may be shaped to overlap the mounting portion of the shock absorber 4.

Reference Signs List 1 Upper arm 11 Upper member 12 Lower member 2 Lower arm 21 Upper member 22 Lower member 4 Shock absorber 7 Reinforcing member 71 First receiving portion 72 Wall portion 73 Second receiving portion 74 Inclined portion 6 Restricting portion 3 Wheel support member 211 Inclined portion 212 Upper portion 213 Lower portion

Claims (3)

A suspension arm having one end connected to a wheel support member and the other end connected to a vehicle body,
The suspension arm has a hollow shape including a plate-shaped upper member having a shock absorber mounting portion and a plate-shaped lower member,
the suspension arm includes a reinforcing member disposed between the upper member and the lower member,
the reinforcing member has a shape including a plate-shaped first receiving portion extending along the extension direction of the suspension arm, a pair of plate-shaped wall portions extending from ends of the first receiving portion in the up-down direction of the vehicle body, and a pair of plate-shaped second receiving portions extending from ends of the wall portions along the extension direction of the suspension arm,
The second receiving portion is in contact with an inner surface of the lower member,
the wall portion has a shape extending in an extension direction of the suspension arm so as to overlap with a mounting portion of the shock absorber,
the first receiving portion is disposed so as to come into contact with an inner surface of a portion where a restricting portion that restricts swing of the suspension arm comes into contact with the upper member ,
A suspension arm in which the wall portion is cut out so that the height from the bottom surface of the second receiving portion at a portion of the end opposite the second receiving portion that does not have the first receiving portion is smaller than the height of the portion where the first receiving portion is provided . The suspension arm according to claim 1, wherein the upper surface of the upper member is formed with an inclined portion so that a height difference is created in the amount of protrusion from the bottom surface of the lower member. The suspension arm according to claim 2, wherein the first receiving portion is in contact with the upper portion formed by the inclined portion, and the tip portion of the wall portion in the direction in which the suspension arm extends is in contact with the lower portion formed by the inclined portion.

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