Steel plate member and method for manufacturing the same

Abstract

To provide a method for manufacturing a steel plate member having a pair of opposed flange portions, the method making it unnecessary that the opposed flange portions are concentrically arranged.SOLUTION: A method for manufacturing a steel plate member according to one embodiment described in the disclosure comprises: a step of burring a peripheral edge portion of a through-hole formed in a first steel plate to form a flange portion, after induction-heating the peripheral edge portion to remove flexure thereof; and a step of press-fitting a bush into the flange portion by making the first steel plate and a second steel pate which have been integrated oppose to each other with the flange portion set inside. In the step of forming the flange portion, the flange portion is extended by repeatedly induction-heating and burring the peripheral edge portion. In the step of press-fitting the bush, a through-hole or a notched portion through which the bush is passed is formed at a site opposing to the flange portion in the second steel plate, and only the flange portion supports the bush.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] As disclosed in Patent Document 1, the inventors developed a method of removing strain from the peripheral portion of a through hole formed in a steel plate by punching by induction heating, and then burring the peripheral portion. Burring is also called stretch flanging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-116635 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have been studying a method for manufacturing a steel plate member in which flange portions of a pair of steel plates, each having flange portions formed by burring, are opposed to each other and bushings are press-fitted into the opposed pair of flange portions. However, in such a steel plate member, the opposed pair of flange portions must be coaxial, which poses a problem of difficulty in manufacturing.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a method for manufacturing a steel plate member that is easy to manufacture and does not require a pair of opposing flange portions to be coaxial. [Means for solving the problem]

[0006] A method for manufacturing a steel plate member according to one embodiment of the present disclosure includes: a step of induction heating a peripheral portion of a through hole formed in a first steel plate to remove distortion, and then burring the peripheral portion to form a flange portion; and a step of placing the integrated first steel plate and second steel plate so that the flange portions face each other and press-fitting a bush into the flange portions, In the step of forming the flange portion, Repeating induction heating and burring of the peripheral edge portion to elongate the flange portion; In the step of press-fitting the bushing, A through-hole or a notch through which the bushing passes is provided in a portion of the second steel plate facing the flange portion, and the bushing is supported only by the flange portion.

[0007] In a method for manufacturing a steel plate member according to one aspect of the present invention, in the step of forming a flange portion on a first steel plate, the flange portion is elongated by repeatedly performing induction heating and burring. Then, in the step of press-fitting a bushing into the flange portion, a through-hole or notch through which the bushing passes is provided in a portion of the second steel plate facing the flange portion of the first steel plate, and the bushing is supported only by the flange portion of the first steel plate. Therefore, there is no need to make the pair of opposing flange portions coaxial, making it easy to manufacture the steel plate member.

[0008] The method may further include a step of welding the first steel plate and the second steel plate to each other with the flange portions facing inward, after the step of forming the flange portions and before the step of press-fitting the bushing. With this configuration, it is not necessary to make the pair of opposed flange portions coaxial in the welding step either, making it easier to manufacture the steel plate member.

[0009] The first and second steel plates may be made of a single flat plate, and after the step of forming the flange portions and before the step of press-fitting the bushings, the flat plate may be formed into a C-shaped cross section with the flange portions on the inside, and the first steel plate and the second steel plate may be arranged to face each other. With this configuration, the welding step can be omitted, making it easier to manufacture the steel plate member.

[0010] When induction heating the peripheral edge portion, an induction heating coil may be inserted into the through hole, thereby making it possible to heat the peripheral edge portion of the through hole with a simple configuration.

[0011] A steel plate member according to one embodiment of the present disclosure includes: a first steel plate having a through hole and a flange portion rising from a peripheral portion of the through hole; a second steel plate disposed opposite the flange portion side of the first steel plate; A steel plate member in which the first and second steel plates are integrated, comprising: a bushing press-fitted into the flange portion; A through-hole or a notch through which the bushing passes is provided in a portion of the second steel plate facing the flange portion, and the bushing is supported only by the flange portion.

[0012] In a steel plate member according to one aspect of the present invention, a through-hole or notch for passing a bush is provided in the second steel plate at a location facing the flange portion of the first steel plate, and the bush is press-fitted into and supported only by the flange portion of the first steel plate. This eliminates the need to make the pair of facing flange portions coaxial, making the steel plate member easier to manufacture. [Effects of the Invention]

[0013] The present disclosure makes it possible to provide a method for manufacturing a steel plate member that is easy to manufacture and does not require a pair of opposing flange portions to be coaxial. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a partial plan view of the steel plate member according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along the line II-II in FIG. [Figure 3] FIG. 10 is a partial plan view showing a modified example of the second steel plate 20. [Figure 4] 3 is a flowchart showing a method for manufacturing a steel plate member according to the first embodiment. [Figure 5] FIG. 6 is a cross-sectional view of a steel plate member according to a second embodiment. [Figure 6] 10 is a flowchart showing a method for manufacturing a steel plate member according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] 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 appropriately for clarity of explanation.

[0016] (First embodiment) <Structure of steel plate components> First, the configuration of a steel plate member according to a first embodiment will be described with reference to Figures 1 and 2. Figure 1 is a partial plan view of the steel plate member according to the first embodiment. Figure 2 is a cross-sectional view taken along the line II-II in Figure 1. The steel plate member shown in Figures 1 and 2 is, but is not limited to, a steel plate member for an automobile, and more specifically, a suspension arm such as a rear upper arm, a rear lower arm, a front upper arm, or a front lower arm.

[0017] Naturally, the right-handed XYZ Cartesian coordinate system shown in Figures 1 and 2 is for the convenience of explaining the positional relationship of the components. In Figure 1 and other figures, the positive direction of the Z axis is vertically upward, and the XY plane is the horizontal plane, which is common to all figures. Furthermore, the steel plate member shown in FIG. 1 is extended in a predetermined direction and has a bent portion, but is not particularly limited thereto.

[0018] The steel plate member shown in FIGS. 1 and 2 includes a first steel plate 10, a second steel plate 20, and a bushing BS. A through hole 11 is formed at the end of the first steel plate 10. As shown in Fig. 2, a cylindrical flange portion 12 rises downward (in the negative direction of the z-axis) from the peripheral edge of the through hole 11. A cylindrical bushing BS is press-fitted into the flange portion 12, as shown in Figs. 1 and 2.

[0019] The through hole 11 is formed, for example, by punching the first steel plate 10. The flange portion 12 is formed by induction heating the peripheral edge of the through hole 11 to remove distortion, and then burring the peripheral edge.

[0020] Here, the flange portion 12 is elongated by repeatedly performing induction heating and burring on the peripheral portion of the through hole 11. For example, the peripheral portion of the through hole 11 is induction heated by inserting a cylindrical induction heating coil into the through hole 11. The peripheral portion of the through hole 11 can be effectively heated with a simple configuration. The heating conditions 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.

[0021] The second steel plate 20 is disposed opposite the flange portion 12 side of the first steel plate 10. A through hole 21 for passing a bushing BS is provided in the second steel plate 20 at a location opposite the flange portion 12 of the first steel plate 10. Therefore, the bushing BS is supported only by the flange portion 12 of the first steel plate 10. The through hole 21 is formed by punching the second steel plate 20, for example.

[0022] Here, Fig. 3 is a partial plan view showing a modified example of the second steel plate 20. In the modified example of the second steel plate 20 shown in Fig. 3, a notch 21a through which a bush BS passes is provided in a portion facing the flange portion 12 of the first steel plate 10. In this way, the through hole 21 shown in Fig. 1 or the notch 21a shown in Fig. 3 is provided in the second steel plate 20 in a portion facing the flange portion 12 of the first steel plate 10.

[0023] As described above, in the steel plate member according to this embodiment, the second steel plate 20 is not provided with a flange portion for supporting the bushing BS, but is provided with the through hole 21 shown in Fig. 1 or the notch 21a shown in Fig. 3. Therefore, it is not necessary to make the pair of opposing flange portions coaxial, which makes it easier to manufacture the steel plate member.

[0024] The first steel plate 10 and the second steel plate 20 are not particularly limited, but may be, for example, high-strength steel plates having a thickness of about 0.5 to 10 mm and a tensile strength of 780 MPa or more. As shown in Fig. 2, the first steel plate 10 and the second steel plate 20 are formed into a square U-shape in cross section in the width direction. Both widthwise ends of the first steel plate 10 and the second steel plate 20 are welded together, and the first steel plate 10 and the second steel plate 20 are integrated together. In other words, the steel plate member is a rectangular tubular member.

[0025] 2, both widthwise end portions of the first steel plate 10 and the second steel plate 20 are overlapped and welded, but this is not particularly limited. For example, both widthwise end portions of the first steel plate 10 and the second steel plate 20 may be butt-welded. Furthermore, as will be described in detail in the second embodiment, the opposing first steel plate 10 and second steel plate 20 may be formed from a single flat plate.

[0026] As described above, in the steel plate member according to this embodiment, the second steel plate 20 has a through hole 21 or notch 21a for passing the bushing BS therethrough in a portion thereof facing the flange portion 12 of the first steel plate 10. The bushing BS is press-fitted into and supported only by the flange portion 12 of the first steel plate 10. That is, in the steel plate member according to this embodiment, the second steel plate 20 does not have a flange portion for supporting the bushing BS, and therefore there is no need to make the pair of opposing flange portions coaxial, making it easier to manufacture the steel plate member.

[0027] <Method of manufacturing steel plate members> Next, a method for manufacturing a steel plate member according to the first embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the method for manufacturing a steel plate member according to the first embodiment.

[0028] 4, the peripheral portion of the through hole 11 formed in the first steel plate 10 is induction heated, and then burring is repeatedly performed to elongate the flange portion 12 (step ST1). For example, a cylindrical induction heating coil is inserted into the through hole 11, and the peripheral portion of the through hole 11 is induction heated to remove strain, and then the peripheral portion is repeatedly burred. On the other hand, the second steel plate 20 is provided with a through hole 21 shown in FIG. 1 or a notch 21a shown in FIG.

[0029] Next, as shown in Fig. 4, the first steel plate 10 and the second steel plate 20 are welded to each other while facing each other with the flange portions 12 facing inward (step ST2). More specifically, as shown in Fig. 2, both widthwise end portions of the first steel plate 10 and the second steel plate 20 are welded to integrate the first steel plate 10 and the second steel plate 20.

[0030] Finally, as shown in Fig. 4, the bushing BS is press-fitted into the flange portion 12 of the first steel plate 10 (step ST3). At this time, the second steel plate 20 has a through-hole 21 shown in Fig. 1 or a notch 21a shown in Fig. 3 formed in a portion facing the flange portion 12, and the bushing BS is supported only by the flange portion 12 of the first steel plate 10.

[0031] As described above, in the method for manufacturing a steel plate member according to this embodiment, in the step of forming the flange portion 12 on the first steel plate 10, the flange portion 12 is elongated by repeatedly performing induction heating and burring. Then, in the step of press-fitting the bushing BS into the flange portion 12, a through-hole 21 or cutout 21a through which the bushing BS passes is provided in the second steel plate 20 at a location facing the flange portion 12 of the first steel plate 10, and the bushing BS is supported only by the flange portion 12 of the first steel plate 10. In other words, in the method for manufacturing a steel plate member according to this embodiment, since the second steel plate 20 does not have a flange portion for supporting the bushing BS, there is no need to make the pair of opposing flange portions coaxial, which makes it easier to manufacture the steel plate member.

[0032] (Second embodiment) <Structure of steel plate components> Next, the configuration of a steel plate member according to a second embodiment will be described with reference to Fig. 5. Fig. 5 is a cross-sectional view of the steel plate member according to the second embodiment. Fig. 5 is a cross-sectional view corresponding to Fig. 2 according to the first embodiment. The planar configuration of the steel plate member according to the second embodiment is the same as the planar configuration of the steel plate member according to the first embodiment shown in FIG.

[0033] In the steel plate member shown in Fig. 2, the first steel plate 10 and the second steel plate 20 are welded together, but in the steel plate member shown in Fig. 5, the first steel plate 10 and the second steel plate 20 are formed from a single flat plate. That is, in the steel plate member shown in Fig. 5, the first steel plate 10 and the second steel plate 20 are already integrated together.

[0034] In the steel plate member shown in Figure 5, as in the first embodiment, a flange portion 12 is provided in a first steel plate 10 of one flat plate, and a through hole 21 is provided in a second steel plate 20 of one flat plate.

[0035] 5, a single flat plate is formed into a C-shape in cross section in the width direction so that the first steel plate 10 and the second steel plate 20 face each other with the flange portion 12 on the inside. Therefore, in the steel plate member according to this embodiment, the welding process of the first steel plate 10 and the second steel plate 20 in the first embodiment can be omitted, making the steel plate member easier to manufacture. Also, manufacturing costs and time can be reduced. In FIG. 5, the opening with a C-shaped cross section is provided on the side surface of the steel plate member, but this is not particularly limited, and it may be provided on the bottom surface, that is, the second steel plate 20, for example.

[0036] Here, a through hole 21 for passing the bushing BS is provided in the second steel plate 20 at a location facing the flange portion 12 of the first steel plate 10. Therefore, the bushing BS is supported only by the flange portion 12 of the first steel plate 10. Instead of the through-hole 21, a notch 21a shown in FIG. The other configurations are the same as those in the first embodiment, and therefore the description will be omitted.

[0037] As explained above, in the steel plate member according to this embodiment, the second steel plate 20 has a through hole 21 or notch 21a for passing the bushing BS in a portion facing the flange portion 12 of the first steel plate 10. The bushing BS is press-fitted into and supported only by the flange portion 12 of the first steel plate 10. That is, in the steel plate member according to this embodiment, the second steel plate 20 does not have a flange portion for supporting the bushing BS, so there is no need to make the pair of opposing flange portions coaxial, and the steel plate member is easy to manufacture.

[0038] Furthermore, in the steel plate member according to this embodiment, the first steel plate 10 and the second steel plate 20 are formed from a single flat plate. This eliminates the need for the welding process between the first steel plate 10 and the second steel plate 20 in the first embodiment, making the steel plate member easier to manufacture. This also reduces manufacturing costs and time.

[0039] <Method of manufacturing steel plate members> Next, a method for manufacturing a steel plate member according to a second embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the method for manufacturing a steel plate member according to the second embodiment.

[0040] First, as shown in FIG. 6, the peripheral portion of a through hole 11 formed in a portion of a flat plate corresponding to the first steel plate 10 is induction heated, and then burring is repeatedly performed to elongate the flange portion 12 (step ST21). On the other hand, a through hole 21 shown in FIG. 5 or a notch 21a shown in FIG. 3 is provided in a portion of one flat plate that corresponds to the second steel plate 20 and faces the flange portion 12 in step ST22.

[0041] Next, as shown in Fig. 6, the single flat plate is formed into a C-shape in cross section in the width direction, with the flange portion 12 facing inward, so that the portion of the single flat plate corresponding to the first steel plate 10 faces the portion of the single flat plate corresponding to the second steel plate 20 (step ST22). This eliminates the need for the welding process of the first steel plate 10 and the second steel plate 20 in the first embodiment, making it easier to manufacture the steel plate member. Furthermore, this reduces manufacturing costs and time.

[0042] Finally, as shown in Fig. 6, the bushing BS is press-fitted into the flange portion 12 of the first steel plate 10 (step ST3). At this time, the second steel plate 20 has a through-hole 21 shown in Fig. 5 or a notch 21a shown in Fig. 3 formed in a portion facing the flange portion 12, and the bushing BS is supported only by the flange portion 12. This step ST3 is common to the first embodiment. The other configurations are the same as those in the first embodiment, and therefore the description will be omitted.

[0043] As explained above, in the method for manufacturing a steel plate member according to this embodiment, in the step of forming the flange portion 12 on the first steel plate 10, the flange portion 12 is elongated by repeating induction heating and burring. Then, in the step of press-fitting the bushing BS into the flange portion 12, a through-hole 21 or cutout 21a through which the bushing BS passes is provided in the second steel plate 20 at a location facing the flange portion 12 of the first steel plate 10, and the bushing BS is supported only by the flange portion 12 of the first steel plate 10. In other words, in the method for manufacturing a steel plate member according to this embodiment, since the second steel plate 20 does not have a flange portion for supporting the bushing BS, there is no need to make the pair of opposing flange portions coaxial, which makes it easier to manufacture the steel plate member.

[0044] Furthermore, in the method for manufacturing a steel plate member according to this embodiment, the first steel plate 10 and the second steel plate 20 are formed from a single flat plate. Therefore, the welding process between the first steel plate 10 and the second steel plate 20 in the first embodiment can be omitted, making it easier to manufacture the steel plate member. Also, manufacturing costs and time can be reduced.

[0045] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0046] 10 First Steel Plate 11 Through hole 12 Flange 20 Second Steel Plate 21 Through hole 21a Notch BS Bush

Claims

1. a step of induction heating a peripheral portion of a through hole formed in a first steel plate to remove distortion, and then burring the peripheral portion to form a flange portion; and a step of placing the integrated first steel plate and second steel plate opposite each other with the flange portions facing inward, and press-fitting a bush into the flange portions, In the step of forming the flange portion, Repeating induction heating and burring of the peripheral edge portion to elongate the flange portion; In the step of press-fitting the bushing, a through-hole or a notch through which the bushing passes is provided in a portion of the second steel plate facing the flange portion, and the bushing is supported only by the flange portion; Manufacturing method of steel plate components.

2. After the step of forming the flange portion and before the step of press-fitting the bushing, further comprising a step of welding the first steel plate and the second steel plate to each other while facing each other with the flange portion facing inward. The method for manufacturing a steel plate member according to claim 1 .

3. The first and second steel plates are formed from a single flat plate, After the step of forming the flange portion and before the step of press-fitting the bushing, The flat plate is formed into a C-shaped cross section with the flange portion facing inward, and the first steel plate and the second steel plate are placed opposite each other. The method for manufacturing a steel plate member according to claim 1 .

4. When induction heating the peripheral portion, an induction heating coil is inserted into the through hole. The method for manufacturing a steel plate member according to any one of claims 1 to 3.

5. a first steel plate having a through hole and a flange portion rising from a peripheral portion of the through hole; a second steel plate disposed opposite the flange portion side of the first steel plate; A steel plate member in which the first and second steel plates are integrated, comprising: a bushing press-fitted into the flange portion; a through-hole or a notch through which the bushing passes is provided in a portion of the second steel plate facing the flange portion, and the bushing is supported only by the flange portion; Steel plate components.

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