WO2014147834A1

WO2014147834A1 - Suspension arm and manufacturing method for suspension arm

Info

Publication number: WO2014147834A1
Application number: PCT/JP2013/058383
Authority: WO
Inventors: 豊黒井; 真二川野
Original assignee: 株式会社ヨロズ
Priority date: 2013-03-22
Filing date: 2013-03-22
Publication date: 2014-09-25
Also published as: JPWO2014147834A1; JP6317330B2

Abstract

[Problem] To provide a vehicle suspension arm that is constructed by connecting a pair of arm plates together and has a stable mounting bush-supporting function. [Solution] A first arm plate (3) is constructed so as to have a first connection part (7) that is formed in an intermediate section in the length direction thereof, first offset parts (9) that are formed at either end in the length direction of the first connection part (7), and first bush mounting parts (11) that are formed on the outer side of the first offset parts (9) in the length direction, and a second arm plate (5) is constructed so as to have a second connection part (23) that is formed in an intermediate section in the length direction thereof, second offset parts (25) that are formed at either end in the length direction of the second connection part (23), and second bush mounting parts (27) that are formed on the outer side of the second offset parts (23) in the length direction. The first connection part (7) and the second connection part (23) are connected together with the first bush mounting parts (11) and the second bush mounting parts (27) being separated from each other in order to construct a suspension arm (1).

Description

Suspension arm and method for manufacturing suspension arm

The present invention relates to a suspension arm used in a vehicle wheel suspension system and a method for manufacturing the suspension arm.

As a suspension arm used in a wheel suspension system, for example, a suspension arm described in Patent Document 1 is known. This suspension arm has a structure in which collars are fixed to both ends of the arm body, and bracket mounting bushes are fixed in each collar by press-fitting, and one bush is a support bolt or support for the bracket on the wheel side. The other bush is rotatably connected to the support bolt or support shaft of the bracket on the vehicle body side and used. The collar is fixed to the arm body by, for example, welding.

In such a suspension arm, since the arm body and the collar are fixed by welding, if a poor welding occurs, the suspension arm may be damaged and a serious accident may occur. In addition, since there is a sudden cross-sectional change in the length direction, stress concentration is likely to occur, and it is necessary to increase the thickness of the collar and arm body to ensure strength and prevent breakage. The weight of the arm must be large.

Therefore, for example, a suspension arm as described in Patent Document 2 (FIG. 1) has been developed. Since the suspension arm here is constructed by connecting a pair of arm plates in which the collar part and the arm body part are integrally formed back to back, there is a problem of insufficient welding between the arm body and the collar. It does not occur and excessive stress concentration does not occur at the connection point to the bracket. A suspension arm constructed by joining a pair of arm plates, in which a collar portion and an arm main body portion are integrally formed, back to back is also described in Patent Document 3 (FIGS. 5 and 6).

JP-A-8-133357 JP 2002-192261 A Japanese Patent No. 4465346

However, in such a suspension arm, since the collar portions of the pair of arm plates are adjacent to each other, it is necessary to make the burring flange of the collar portion protrude outwardly (see Patent Document 2). That is, in order to stably support the bush press-fitted into the collar portion, both ends in the axial direction of the bush must be supported by the collar portion, but the collar portion of the arm plate is in an adjacent state. If the protruding amount of the burring flange of the collar portion is reduced as described in Patent Document 3 (FIGS. 5 and 6), the bush fixing structure supports only the axial middle portion of the bush. . However, even if the burring flange is protruded largely outward as in Patent Document 2, the support strength on the tip side of the burring flange is low, so that the bush cannot be supported sufficiently stably. Here, when a cylindrical suspension arm having a rectangular cross section as described in FIG. 11 of Patent Document 2 is used, both axial ends of the bush can be supported even if the protrusion amount of the burring flange is reduced. However, in the case of a cylindrical suspension arm, the burring flange forming operation becomes complicated.

The present invention provides a suspension arm for a vehicle configured by connecting a pair of arm plates, and provides a suspension arm that can stably support a mounting bush, and a method for manufacturing such a suspension arm for a vehicle. With the goal.

To achieve this object, a vehicle suspension arm according to the present invention is a vehicle suspension arm, and includes a first arm plate having a reinforcing rising portion formed at a peripheral edge, and a reinforcing rising edge at a peripheral edge. And a second arm plate connected to the first arm plate, wherein the first arm plate has first end portions in the longitudinal direction in which the first bush mounting holes are formed. 1 bush attachment portion, a first connection portion in the middle in the length direction, and a first offset portion between the first connection portion and the first bush attachment portion, integrally. The second arm plate has a second bush mounting portion at both ends in the length direction in which a second bush mounting hole is formed, and the rising portions of the first connection portion face outward. A second connecting portion of the intermediate portion in the longitudinal direction fixedly connected to the second connecting portion and a second offset portion between the second connecting portion and the second bush mounting portion. The first offset portion and the second offset portion are bent or curved outward so as to separate the first bush attachment portion and the second bush attachment portion, respectively. The bush mounting hole has a first burring flange projecting outward or inward, and the second bush mounting hole has a second burring flange projecting outward or inward. The first bush mounting portion of the first arm plate and the second bush mounting portion of the second arm plate are not adjacent but separated in the axial direction. Therefore, the first bush mounting hole and the second bush mounting hole can firmly support both axial ends of the bush (for example, the outer annular body of the bush), so that the fixing strength of the bush can be increased. It becomes. For example, even if the first burring flange projecting outside the first bush mounting hole and the second burring flange projecting outside the second bush mounting hole are formed low, both axial ends of the bush are formed. The first burring flange and the second burring flange may be formed so as to protrude inward as long as the first bushing mounting portion and the second bushing mounting portion have a large degree of separation. The both ends of the bush in the axial direction can be supported. The first burring flange and the second burring flange can be easily provided when forming the first arm plate and the second arm plate.

When the connection between the first arm plate and the second arm plate is performed using spot welding as described in Patent Document 2 and Patent Document 3, it takes time and effort to manufacture the suspension arm efficiently. The first connection portion or the second connection portion by plastic deformation or caulking (including plastic deformation or caulking of both the first connection portion and the second connection portion). It is preferable to connect the two connecting portions. Specifically, a fixing hole is provided in the first connecting portion, and a fixing burring flange that is passed through the fixing hole is formed in the second connecting portion, and the fixing burring flange that is passed through the fixing hole is formed. The tip end portion is engaged with the fixing hole or the periphery of the fixing hole by plastic deformation or caulking, and the first connecting portion and the second connecting portion are fixed and connected. The fixing hole and the fixing burring flange can be formed in a circular shape, but may have other shapes such as a square shape.

One side mounting bushing is press-fitted into the first bushing mounting hole on one side and the second bushing mounting hole on one side, and the first bushing mounting hole on the other side and the second bushing mounting on the other side are mounted. The suspension arm can be configured by press-fitting the other mounting bush into the hole.

A vehicle suspension arm manufacturing method according to the present invention is a vehicle suspension arm manufacturing method, comprising: a first bushing hole having a first burring flange; The first bush mounting portion, the first connection portion at the intermediate portion in the longitudinal direction, and the first offset portion between the first connection portion and the first bush mounting portion are integrally provided. And second bushing attachments at both ends in the longitudinal direction in which a first arm plate formed with protruding rising portions at the periphery and a second bushing attachment hole having a second burring flange are formed. Part, a second connection part in the middle in the length direction, and a second offset part between the second connection part and the second bush mounting part, and reinforced at the periphery Standing for A preparatory step of preparing a second arm plate formed by protruding a beam portion, and abutting the second connection portion with the first connection portion so that the rising portions of each other face outward The positioning step, the first bush mounting hole on one side and the second bush mounting hole on one side are positioned coaxially, and the first bush mounting hole on the other side and the second bush on the other side A positioning step of coaxially positioning the bush mounting hole and the axial direction of the first bush mounting hole on one side and the second bush mounting hole on one side, or the first bush mounting on the other side By pressing the first connection part or the second connection part in the axial direction of the hole and the second bushing attachment hole on the other side, and plastically deforming or caulking (the first connection part and And connecting the first connecting portion and the second connecting portion fixedly connected to each other. . The reinforcing rising portion of the first arm plate can be formed so as to protrude in the same direction as the first burring flange. The reinforcing rising portion of the second arm plate can be formed so as to protrude in the same direction as the second burring flange. The axial direction of the first bush mounting hole on one side and the second bush mounting hole on one side and the axial direction of the first bush mounting hole on the other side and the second bush mounting hole on the other side are, for example, The same direction. In the axial direction of the first bush mounting hole on one side and the second bush mounting hole on one side, or in the axial direction of the first bush mounting hole on the other side and the second bush mounting hole on the other side, In order to pressurize and plastically deform or caulk the first connection part or the second connection part, for example, the pressure member is moved in the axial direction of the bush mounting hole to thereby make the first connection part or the second connection. The part may be pressurized and plastically deformed or caulked. With this configuration, the connection process and the positioning process can be easily performed at the same time. For example, if a positioning and pressing member that performs positioning (for example, press-fitting of a mounting bush) and pressurization is configured and this positioning and pressing member is moved (for example, lowered) in one direction to perform positioning and pressing, connection The process and the positioning process are performed at the same time. Here, in order to connect the first arm plate and the second arm plate and fix the mounting bush, the positioning pressure member may be operated in one step.

In the positioning step, the first bush mounting hole on the one side and the second bush on the one side are pressed by press-fitting the mounting bush on the one side into the first bush mounting hole on the one side and the second bush mounting hole on the one side. The first bushing on the other side is press-fitted into the first bushing mounting hole on the other side and the second bushing mounting hole on the other side by press-fitting the bushing mounting hole on the other side. The mounting hole and the second bushing mounting hole on the other side are preferably positioned coaxially.

In addition, a fixing hole is formed in the first connecting portion, and a fixing burring flange that is passed through the fixing hole is formed in the second connecting portion, and the fixing burring flange penetrates the fixing hole in the arranging step. The second connecting portion is brought into contact with the first connecting portion, and in the connecting step, the tip of the fixing burring flange is pressurized and plastically deformed or caulked, and the fixing hole or the periphery of the fixing hole is engaged. The first connecting portion and the second connecting portion can be fixed and connected together. The fixing hole and the fixing burring flange can be formed in a circular shape, but may have other shapes such as a square shape.

According to the suspension arm and the manufacturing method of the suspension arm of the present invention, it is possible to provide a suspension arm composed of a pair of arm plates capable of firmly fixing the mounting bush.

1 is a perspective view of a suspension arm according to the present invention. It is a disassembled perspective view of a suspension arm. It is sectional drawing of a suspension arm. It is an enlarged view which shows a fixing hole and a burring flange part for fixing. It is an enlarged view which shows the bush part for attachment. It is a figure which shows the use condition of a suspension arm. It is a figure which shows the preparatory process of a 1st arm plate and a 2nd arm plate. It is a figure which shows the arrangement | positioning process of a 1st arm plate and a 2nd arm plate. It is a figure which shows the positioning process of a 1st arm plate and a 2nd arm plate, and is a figure which shows the press injection start state to the bush attachment hole of the bush for attachment. It is a figure which shows the positioning process of a 1st arm plate and a 2nd arm plate, and is a figure which shows the state which press-fitted the bush for attachment to the bush attachment hole to the middle. It is a figure which shows the positioning process and connection process of a 1st arm plate and a 2nd arm plate, and is a figure which shows the state which press-fits the whole bush for attachment to the bush attachment hole, and crimped the burring flange for fixation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the configuration of the suspension arm according to the present invention will be described with reference to FIGS.

The suspension arm 1 is configured by connecting a first arm plate 3 and a second arm plate 5.

The first arm plate 3 is made of steel and is formed in a thin and thin plate shape. The first connecting portion 7 in the middle portion in the longitudinal direction and the first connecting portions 7 on both sides in the longitudinal direction of the first connecting portion 7 are formed. Of the first offset portion 9 and the first bush mounting portion 11 on the outer side in the longitudinal direction of each first offset portion 9, and the rising portion 13 is integrally formed on the outer peripheral edge over the entire circumference. ing. The first connection portion 7 is formed in a flat plate shape and has fixing holes 15 on both sides in the length direction. Each first offset portion 9 is inclined outward by 7 to 10 degrees from the outer end in the length direction of the first connecting portion 7 and extends outward in the length direction, and the first bush attachment portion 11 is The first offset portion 9 extends outward in the longitudinal direction in a stepped state in parallel with the first connecting portion 7 from the outer end in the length direction. Each first bush attachment portion 11 is formed with a first bush attachment hole 17, and the first bush attachment hole 17 has a burring flange (first burring flange) 19 rising outward. Yes. In addition, the outer edge (upper edge) 21 of the rising part 13 is located at the same or substantially the same height over the entire circumference except for both end edges in the length direction. Further, the burring flange 19 may be formed so as to protrude inward.

The second arm plate 5 is also made of steel and is formed in a thin and thin plate shape. The second connecting portion 23 in the middle portion in the longitudinal direction and the second connecting portions 23 on both sides in the longitudinal direction of the second connecting portion 23. Of the first offset portion 25 and the second bushing mounting portion 27 on the outer side in the longitudinal direction of each of the second offset portions 25, and the rising portion 29 is integrally provided on the outer peripheral edge over the entire circumference. ing. The second connection portion 23 is formed in a flat plate shape, and has burring flanges 31 protruding on the opposite side to the rising portion 29 on both sides in the length direction corresponding to the fixing hole 15. Each second offset portion 25 extends outward in the length direction by inclining 7 degrees to 10 degrees outward from the outer end in the length direction of the second connection portion 23, and the second bush mounting portion 27 is The second offset portion 25 extends outward in the longitudinal direction in a stepped state parallel to the second connection portion 23 from the outer end in the length direction. Each second bush mounting portion 27 is formed with a second bush mounting hole 33, and the second bush mounting hole 33 has a burring flange (second burring flange) 35 that rises outward. Yes. The outer end edge (lower end edge) 37 of the rising portion 29 is located at the same or substantially the same height over the entire circumference except for both end edges in the length direction. Further, the burring flange 35 can be formed so as to protrude inward.

The second arm plate 5 has the same shape as the first arm plate 3 except for the difference between the fixing hole 15 and the burring flange 31. In addition, although the fixing hole 15 and the burring flange 31 are circular here, it can also be formed in square shape, for example.

In the first arm plate 3 and the second arm plate 5, the first connection portion 7 and the second connection portion 23 are back to back (the surface on the opposite side of the rising portion 13 of the first connection portion 7 ( (The back surface) 39 and the surface (the back surface) 41 opposite to the rising portion 29 of the second connecting portion 23), the second connecting portion 23 in the fixing hole 15 of the first connecting portion 7. The burring flange 31 is connected by caulking the tip of the burring flange 31 with the burring flange 31 inserted. Here, the crimped tip end portion of the burring flange 31 is engaged with the surface side peripheral edge of the fixing hole 15 of the first connecting portion 7 or the surface around the fixing hole 15 of the first connecting portion 7 to prevent the burring flange 31 from coming off. Since the outer periphery of the base portion of the burring flange 31 is curved and has a larger diameter than the fixing hole 15 at the base end, the back surface 39 of the first connection portion 7 and the back surface 41 of the second connection portion 23 are not It is in a contact state (see FIG. 4). Therefore, it is possible to prevent the back surface 39 of the first connection portion 7 and the back surface 41 of the second connection portion 23 from being rubbed and peeling off the paint in a wide range.

The first bush mounting hole 17 on one side and the second bush mounting hole 33 on one side, and the first bush mounting hole 17 on the other side and the second bush mounting hole 33 on the other side are respectively brackets. A mounting bush 43 is press-fitted and fixed. The mounting bush 43 includes a metal outer annular body 45 and a metal mounting pipe 49 attached to the outer annular body 45 via a rubber ring 47 so as to penetrate the outer annular body 45. The outer annular body 45 has one end edge in the axial direction and the other end edge in the axial direction at the outer end edge (axial outer end edge) of the first burring flange 19 of the first bush mounting hole 17 and the second bush. The mounting hole 33 is press-fitted into the first bush mounting hole 17 and the second bush mounting hole 33 so as to coincide with the outer end edge (axial outer end edge) of the second burring flange 35 of the mounting hole 33. That is, the outer annular body 45 of the mounting bush 43 has an outer edge of the first burring flange 19 of the first bush mounting hole 17 and an outer edge of the second burring flange 35 of the second bush mounting hole 33. And both ends in the length direction (axial direction) are press-fitted and supported by the first bush mounting hole 17 and the second bush mounting hole 33 (see FIG. 5, FIG. 5). Represents 43 mounting bushes on one side, but the 43 mounting bushes on the other side have the same structure). Both ends of the attachment pipe 49 in the length direction (axial direction) protrude outward from both axial ends of the outer annular body 45.

As shown in FIG. 6, the suspension arm 1 having such a structure is inserted into the mounting pipe 49 of the mounting bush 43 on one side by inserting the support bolts 53 of the vehicle body side bracket 51 and tightened with the nuts 54. The pipe 49 is rotatably attached to the vehicle body side bracket 51, and the support bolt 57 of the wheel side bracket 55 is inserted into the attachment pipe 49 of the attachment bush 43 on the other side and tightened with the nut 58. It is attached to the wheel side bracket 55 so as to be rotatable.

Next, a method for manufacturing the suspension arm 1 will be described with reference to FIGS.

First, as shown in FIG. 7, the first arm plate 3 is formed from one thin steel plate 59 by press molding, and the second arm plate 5 is formed from one thin steel plate 61 by press molding. Necessary coating is applied to the molded first arm plate 3 and second arm plate 5 (preparation step).

Next, as shown in FIG. 8, the first connection portion and the second connection portion are back to back so that the burring flange 31 of the second connection portion is inserted into the fixing hole 15 of the first connection portion. In contact (placement step). Then, as shown in FIG. 9, separately prepared mounting bushes 43 are placed on the first bush mounting holes 17 on one side and the other side, and the mounting bushes 43 on one side and the other side are placed on the first arm. A press-fitting member (pressurizing member, pressurizing positioning member) 63 is positioned so that it can be pushed down with respect to the plate 3 and the second arm plate 5. The press-fitting member 63 is a thick plate body, has bush pressing portions 65 on both sides in the length direction, and has a pair of frustoconical punches 67 corresponding to the burring flange 31 in the middle portion. Each of the portions 65 is formed with an insertion hole 69 having a diameter smaller than that of the outer annular body 45 of the mounting bush 43 and larger than that of the mounting pipe 49, and each bush pressing portion 65 is inserted into the insertion pipe 69. It is comprised so that the upper end edge of the outer side annular body 45 of the bush 43 for attachment may be pressed in the state which accommodated this protrusion end part. As shown in FIG. 10, the press-fitting member 63 descends (in the direction of arrow A, also described in FIG. 9) to press the mounting bushes 43 on one side and the other side with the respective bush pressing portions 65. Each of the mounting bushes 43 is pushed into the first bushing mounting hole 17 on the one side and the other side and the second bushing mounting hole 33 on the one side and the other side (FIG. The state where it is press-fitted halfway into the bush mounting hole 33 is shown). The first bush mounting hole 17 on one side and the first bush mounting hole 17 on one side are inserted by press-fitting the one mounting bush 43 into the first bush mounting hole 17 on one side and the second bush mounting hole 33 on one side. The second bushing mounting hole 33 is positioned coaxially (in the same direction as the arrow A), and the other side mounting bushing 43 into the first bushing mounting hole 17 on the other side and the second bushing mounting hole 33 on the other side. The first bush mounting hole 17 on the other side and the second bush mounting hole 33 on the other side are also positioned coaxially (in the same direction as the arrow A). When each mounting bush 43 is press-fitted halfway into the second bush mounting hole 33, the punch 67 reaches the height position of the tip of the burring flange 31. Then, as shown in FIG. 11, the press-fitting member 63 contacts the outer edge 21 of the rising portion 13, and the lower end of the mounting bush 43 (outer annular body 45) reaches the lower end of the second bush mounting hole 33. Sometimes, the press-fitting of the mounting bush 43 is completed, and the caulking of the tip of the burring flange 31 by the punch 67 is also completed. Thereafter, the press-fitting member 63 rises, but the positioning step and the connecting step started by the lowering of the press-fitting member 63 are finished by this rise of the press-fitting member 63.

The suspension arm of the present invention can be used, for example, in a wheel suspension device for a private car.

DESCRIPTION OF SYMBOLS 1 Suspension arm 3 1st arm plate 5 2nd arm plate 7 1st connection part 9 1st offset part 11 1st

bush attachment part

13, 29 Standing part 17 1st bush attachment hole 19 1st Burring flange 23 Second connecting portion 25 Second offset portion 27 Second bush attachment portion 29 Standing portion 33 Second bush attachment hole 35 Second burring flange

Claims

A suspension arm for a vehicle,
A first arm plate having a rising portion for reinforcement formed on the periphery, and a second arm plate formed with a rising portion for reinforcement on the periphery and connected to the first arm plate,
The first arm plate includes a first bush attachment portion at both ends in the length direction in which a first bush attachment hole is formed, a first connection portion at an intermediate portion in the length direction, and the first connection. And a first offset part between the first bushing attaching part and the first bushing attaching part,
The second arm plate has a second bush attachment portion at both ends in the length direction in which a second bush attachment hole is formed, and the rising portions of the first connection portion are directed outward. The second connecting portion of the intermediate portion in the length direction fixedly connected and the second offset portion between the second connecting portion and the second bush mounting portion are integrally provided. And
The first offset portion and the second offset portion are bent or curved outwardly so as to separate the first bush attachment portion and the second bush attachment portion, respectively.
The first bush mounting hole has a first burring flange protruding outward or inward, and the second bush mounting hole has a second burring flange protruding outward or inward. Features suspension arm.
2. The first connection part and the second connection part are fixed and connected by plastic deformation or caulking of the first connection part or the second connection part. The suspension arm described.
The first connecting portion is provided with a fixing hole, and the second connecting portion is formed with a fixing burring flange that is passed through the fixing hole, and the distal end portion of the fixing burring flange is plastically deformed. 3. The suspension according to claim 2, wherein the fixing hole or the periphery of the fixing hole is engaged by caulking to fix and connect the first connection portion and the second connection portion. arm.
The first bush mounting hole on one side and the second bush mounting hole on one side are fitted with a mounting bush on one side, and the first bush mounting hole on the other side and the other side are attached. 4. The suspension arm according to claim 1, wherein a mounting bush on the other side is press fitted into the second bush mounting hole.
A method for manufacturing a suspension arm for a vehicle,
A first bush mounting portion at both ends in the length direction in which a first bush mounting hole having a first burring flange is formed; a first connection portion at a middle portion in the length direction; and the first connection portion. And a first offset portion between the first bush mounting portions, and a first arm plate formed by protruding a rising portion for reinforcement on the periphery, and a second burring flange A second bush mounting portion at both ends in the length direction in which a second bush mounting hole is formed, a second connection portion at a middle portion in the length direction, the second connection portion, and the second connection portion. A second arm plate integrally having a second offset portion between the bush mounting portions, and a second arm plate formed by protruding a rising portion for reinforcement on the periphery;
An arrangement step of bringing the second connection portion into contact with the first connection portion so that the rising portions of the first connection portion face outward.
The first bush mounting hole on one side and the second bush mounting hole on one side are positioned coaxially, and the first bush mounting hole on the other side and the second bush mounting hole on the other side are positioned. Positioning step for coaxially positioning,
The axial direction of the first bush mounting hole on one side and the second bush mounting hole on one side, or the first bush mounting hole on the other side and the second bush mounting hole on the other side. A connection that fixes and connects the first connection portion and the second connection portion by pressing the first connection portion or the second connection portion in the axial direction to cause plastic deformation or caulking. And a suspension arm manufacturing method comprising the steps of:
6. The method of manufacturing a suspension arm according to claim 5, wherein the connecting step is performed simultaneously with the positioning step.
In the positioning step, the first bushing mounting hole on one side and the one side are pressed by press-fitting the mounting bushing on one side into the first bushing mounting hole on one side and the second bushing mounting hole on one side. Positioning the second bushing mounting hole on the side coaxially, and press fitting the mounting bushing on the other side into the first bushing mounting hole on the other side and the second bushing mounting hole on the other side 7. The method for manufacturing a suspension arm according to claim 5, wherein the first bush mounting hole on the other side and the second bush mounting hole on the other side are positioned coaxially.
A fixing hole is formed in the first connection portion, and a fixing burring flange that is passed through the fixing hole is formed in the second connection portion,
In the arranging step, the second connecting portion is brought into contact with the first connecting portion so that the fixing burring flange penetrates the fixing hole,
In the connecting step, the first connecting portion and the second connecting portion are pressed and plastically deformed by caulking the tip of the fixing burring flange or engaged with the fixing hole or the periphery of the fixing hole. The suspension arm manufacturing method according to claim 5, wherein the suspension arm is fixed and connected.