Suspension arm member and manufacturing method of the same

Abstract

To provide a suspension arm member and a manufacturing method of the same in which a bush is press-fitted without welding a steel pipe member to form a cylindrical part so that difficulty in the manufacturing is largely decreased.SOLUTION: A suspension arm member is given in which a body part and a cylindrical part for bush press-fit are constituted of one steel plate. The cylindrical part is a through hole at a side wall part standing in a press direction in the body part in which a peripheral edge part of the through hole is formed by burring process. Thereby, weldment of the cylindrical part for bush press-fit that is a steel pipe member is unnecessary to provide the suspension arm member that is further easily manufactured.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a suspension arm member and a method for manufacturing the same. [Background technology]

[0002] For example, the vehicle lower arm disclosed in Patent Document 1 is manufactured by welding a steel pipe member for press-fitting a bush to a main body made of a press-formed steel plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-137037 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of suspension arm components such as the lower arm, when welding a steel pipe member to the main body, it is required to weld the steel pipe member perpendicular to the pressing direction of the main body. In this case, the steel pipe weld is processed in a separate process and then welded to the steel pipe member, but manufacturing is difficult due to the need to ensure dimensional accuracy when processing the steel pipe weld, the need to ensure weld quality when welding the steel pipe member, and the fact that the shape is difficult to form.

[0005] The present disclosure has been made in consideration of the above-described circumstances, and provides a suspension arm member that can be manufactured more easily, and a method for manufacturing a suspension arm member. [Means for solving the problem]

[0006] A suspension arm member according to one aspect of the present disclosure includes: a main body made of a press-formed steel plate; a cylindrical portion provided on the main body portion so that a bushing can be press-fitted into the cylindrical portion in a direction perpendicular to a pressing direction of the main body portion, The main body and the cylindrical portion are made of a single steel plate, The cylindrical portion is formed by burring the peripheral edge of a through hole provided in a side wall portion of the main body portion that rises in the pressing direction.

[0007] In one aspect of the suspension arm member of the present invention, the main body and the tubular portion for press-fitting the bushing are made from a single steel plate, and the tubular portion is formed by burring the periphery of a through hole provided in a side wall portion of the main body that rises in the pressing direction. This eliminates the need to weld the tubular portion for press-fitting the bushing, i.e., the steel pipe member, making manufacturing easier.

[0008] A method for manufacturing a suspension arm member according to one aspect of the present disclosure includes: A step of press-forming a steel sheet; providing a through hole in the steel plate; a step of locally inductively heating a peripheral portion of the through hole; a step of forming a cylindrical portion into which a bushing is press-fitted by burring a peripheral portion of the through hole; and bending the portion of the steel plate where the cylindrical portion is formed to form a side wall portion that rises in the pressing direction.

[0009] In one aspect of the present invention, a method for manufacturing a suspension arm member includes locally inductively heating the periphery of a through hole in a steel plate, then forming a cylindrical portion for press-fitting a bushing by burring, and bending the steel plate at the location where the cylindrical portion is formed to form a side wall portion that rises in the pressing direction. This eliminates the need to weld the cylindrical portion for press-fitting the bushing, i.e., the steel pipe member, making it easier to manufacture the suspension arm member.

[0010] In addition, in the step of forming the cylindrical portion, the flange portion may be elongated by repeatedly performing induction heating on the peripheral edge of the through hole and burring on the peripheral edge of the through hole. With this configuration, it is possible to ensure that the cylindrical portion has a length sufficient to support the bushing. [Effects of the Invention]

[0011] The present disclosure provides a suspension arm member that can be manufactured more easily, and a method for manufacturing a suspension arm member. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic perspective view of a suspension arm member according to the present disclosure. [Figure 2] 1 is a schematic side view of a suspension arm member according to the present disclosure. FIG. [Figure 3] 1 is a flowchart illustrating a method for manufacturing a suspension arm component according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, specific embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings have been simplified as appropriate for clarity of explanation.

[0014] <Configuration of suspension arm components> First, the configuration of a suspension arm member according to one embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a schematic perspective view of the suspension arm member according to the present disclosure. Figure 2 is a side view of Figure 1. The type of suspension arm is not particularly limited, but examples include a front lower arm, a front upper arm, a rear lower arm, a rear upper arm, and a trailing arm. Figure 1 shows a schematic perspective view of a front lower arm as an example.

[0015] The right-handed xyz Cartesian coordinate system shown in Figures 1 and 2 is for the convenience of showing the positional relationship of the components. In Figures 1 and 2, the positive direction of the z axis is vertically upward, and the xy plane is the horizontal plane, which is common to all the drawings.

[0016] The suspension arm member shown in Fig. 1 comprises a main body 1 made from a press-formed steel plate, and a cylindrical portion 2 provided on the main body so that a bushing is press-fitted in a direction perpendicular to the pressing direction of the main body (positive direction of the y-axis). The cylindrical portion 2 is formed on the periphery of a through-hole 12 provided in a side wall portion 11 of the main body 1 that rises in the pressing direction.

[0017] The main body 1 and the cylindrical portion 2 are made of a single steel plate. The outer shape of the main body 1 may be changed as necessary to fulfill its function as a suspension arm. For example, in Figure 1, the outer shape of the main body is L-shaped extending in the positive x-axis direction and the positive y-axis direction, with projections and recesses provided all over the main body, and multiple holes provided for purposes such as weight reduction, stress distribution, and connection to other components. However, the configuration, such as the outer shape, the presence or absence of projections and recesses, and the size and number of holes, is not limited to that shown in Figure 1.

[0018] The cylindrical portion 2 is provided on the side wall portion 11. The cylindrical portion 2 is formed by elongating it by repeatedly subjecting the peripheral portion of the through hole 12 to induction heating and burring. Note that in FIG. 2, the cylindrical portion 2 is formed by elongating it in the positive direction of the y-axis, but it may also be formed by elongating it in the negative direction of the y-axis. The elongation direction is uniquely determined by the direction in which the bushing BS is press-fitted. Furthermore, the length of the cylindrical portion 2 in the y-axis direction is not particularly limited as long as it is long enough to support the bushing BS, but is, for example, approximately 10 to 15 mm. Furthermore, in FIG. 1, the cylindrical portion 2 is formed at the end of the side wall portion 11, but the formation position is not particularly limited. In addition, multiple cylindrical portions 2 may be provided on the side wall portion 11.

[0019] The side wall 11 is configured to rise at a certain angle in the z-axis direction with respect to the xy plane on which the main body 1 exists. Note that, although the side wall 11 is depicted in Fig. 2 as rising perpendicularly (in the negative direction of the z-axis) with respect to the main body 1, the angle at which the side wall 11 rises with respect to the main body 1 may be changed to the extent that the cylindrical portion 2 and the bushing BS press-fitted into the cylindrical portion 2 do not interfere with the main body 1 and the side wall 11.

[0020] The through hole 12 is formed by punching out a press-formed steel plate, for example. The diameter of the through hole 12 is determined depending on the size of the bushing BS to be press-fitted.

[0021] As explained above, in the suspension arm member according to one aspect of the present invention, the main body 1 and the tubular portion 2 for press-fitting the bushing are made from a single steel plate, and the tubular portion 2 is formed by burring the peripheral edge of the through hole 12 provided in the side wall portion 11 that rises in the pressing direction of the main body 1. In other words, the suspension arm member according to one aspect of the present invention does not require welding of the tubular portion for press-fitting the bushing, i.e., the steel pipe member, and can be manufactured more easily.

[0022] <Method of manufacturing a suspension arm component> Next, a method for manufacturing a suspension arm member will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the method for manufacturing a suspension arm member.

[0023] First, as shown in Fig. 3, a steel plate is press-formed to form the main body 1 (step ST1). At this time, the outer shape is changed and irregularities are provided as necessary so as to fulfill the function of a suspension arm.

[0024] 3, through holes 12 are formed in the main body 1 (step ST2). The through holes 12 are formed, for example, by punching out a press-formed steel plate.

[0025] 3, the peripheral portion of through-hole 12 is induction heated (step ST3). Here, the heating conditions for induction heating are, for example, a heating temperature of about 500 to 830°C and a heating time of 10 seconds or less. However, the heating time may exceed 10 seconds.

[0026] 3, the cylindrical portion 2 is formed by burring the peripheral portion of the through hole 12 (step ST4). Here, in order to ensure the length of the cylindrical portion 2 necessary to support the bushing, the induction heating of the peripheral portion of the through hole 12 and the burring may be repeated to elongate the cylindrical portion 2. Furthermore, there is no particular limitation on the number of times that the induction heating and the burring are repeated.

[0027] 3, the main body 1 with the cylindrical portion 2 formed thereon is folded to form the side wall 11 including the cylindrical portion 2 (step ST5). At this time, it is not limited whether the main body 1 is folded with the surface on the side with the cylindrical portion 2 formed thereon facing inward or outward.

[0028] As described above, in the method for manufacturing a suspension arm member according to one aspect of the present invention, through hole 12 is formed in main body 1 of press-formed steel plate, and tubular portion 2 is formed by burring the periphery of through hole 12. In other words, in the method for manufacturing a suspension arm member according to one aspect of the present invention, welding of tubular portion 2, i.e., steel pipe member, for press-fitting a bushing is not required, and manufacturing is easier. [Explanation of symbols]

[0029] 1 Main body 2 Cylindrical part 11 Side wall 12 Through holes BS Bush

Claims

1. a main body made of a press-formed steel plate; a cylindrical portion provided on the main body portion so that a bushing can be press-fitted into the cylindrical portion in a direction perpendicular to a pressing direction of the main body portion, the main body and the cylindrical portion are made of a single steel plate, The cylindrical portion is formed by burring a peripheral portion of a through hole provided in a side wall portion of the main body portion that rises in the pressing direction. Suspension arm components.

2. a step of press-forming a steel sheet; providing a through hole in the steel plate; a step of locally inductively heating a peripheral portion of the through hole; a step of forming a cylindrical portion into which a bushing is press-fitted by burring a peripheral portion of the through hole; and a step of bending the portion of the steel plate where the cylindrical portion is formed to form a side wall portion rising in the pressing direction. A method for manufacturing a suspension arm component.

3. In the step of forming the cylindrical portion, The cylindrical portion is elongated by repeating induction heating of the peripheral portion of the through hole and burring of the peripheral portion of the through hole. The method for manufacturing a suspension arm member according to claim 2.

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