Steel sheet member and method for producing same

Abstract

To provide a steel plate member capable of suppressing deformation due to bolt fastening without depending on pipe welding.SOLUTION: A steel sheet member according to an aspect of the present disclosure is a tubular steel sheet member including a first steel sheet including a through-hole and a tubular burring portion rising from a peripheral edge portion of the through-hole, and a second steel sheet disposed to face a burring portion side of the first steel sheet and provided with a through-hole at a portion facing the burring portion, in which the first and second steel sheets are welded. When fastened to another member by a bolt via the through-holes of the first and second steel plates, the burring part abuts on the second steel plate to support the bolt.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] For example, as disclosed in Patent Document 1, in steel plate members such as suspension members having a cylindrical structure (hollow structure), a pipe is welded to the bolt fastening portion to suppress deformation due to bolt fastening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 64-83384 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned method of welding pipes has problems such as the time-consuming task of aligning the welding position and the possibility of welding defects. Therefore, a method of suppressing deformation caused by bolt fastening without using welding is desired.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a steel plate member that can suppress deformation due to bolt fastening without using pipe welding, and a manufacturing method thereof. [Means for solving the problem]

[0006] A steel plate member according to one embodiment of the present disclosure includes: a first steel plate having a through hole and a cylindrical burring portion rising from a peripheral portion of the through hole; A cylindrical steel plate member in which the first and second steel plates are welded together, comprising: a second steel plate arranged opposite the burring portion side of the first steel plate and having a through hole provided in a portion opposite the burring portion; When the first and second steel plates are fastened to another member by bolts passing through the through holes in the first and second steel plates, the burring portion abuts against the second steel plate to support the bolt.

[0007] In a steel plate member according to one aspect of the present invention, when the steel plate member is fastened to another member by a bolt passing through the through holes of the first and second steel plates, the burred portion rising from the periphery of the through hole of the first steel plate abuts against the second steel plate to support the bolt. In other words, deformation of the steel plate member due to bolt fastening can be suppressed by the burred portion formed by burring, rather than by a welded pipe.

[0008] The steel plate member may be a suspension member.

[0009] 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 burred portion; and welding a second steel plate, which has a through hole provided in a portion facing the burring portion, to the first steel plate with the burring portion facing inward to form a tubular steel plate member, When the steel plate member is fastened to another member by a bolt through the through holes in the first and second steel plates, the burring portion abuts against the second steel plate to support the bolt.

[0010] In a method for manufacturing a steel plate member according to one aspect of the present invention, when the steel plate member is fastened to another member with a bolt passing through the through holes in the first and second steel plates, the burred portion formed on the periphery of the through hole in the first steel plate abuts against the second steel plate to support the bolt. In other words, the burred portion formed by burring, rather than a welded pipe, can suppress deformation of the steel plate member due to bolt fastening without welding.

[0011] In the step of forming the burred portion, the burred portion may be elongated by repeatedly performing induction heating of the peripheral edge portion and burring, thereby preventing cracks and the like that may occur due to burring.

[0012] 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. [Effects of the Invention]

[0013] The present disclosure provides a steel plate member and a method for manufacturing the same that can suppress deformation due to bolt fastening without using pipe welding. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of a steel plate member according to a first embodiment. [Figure 2] FIG. 4 is a cross-sectional view of a steel plate member according to a comparative example. [Figure 3] 3 is a flowchart showing a method for manufacturing a steel plate member according to the first embodiment. [Figure 4] 1 is a cross-sectional view showing a method for manufacturing a steel plate member according to a first 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 Fig. 1. Fig. 1 is a cross-sectional view of the steel plate member according to the first embodiment. The steel plate member shown in Fig. 1 has a tubular structure (hollow structure) formed by welding a pair of steel plates. The steel plate member is not particularly limited, but may be, for example, a steel plate member for an automobile, and more specifically, may be, for example, a suspension member.

[0017] Naturally, the right-handed XYZ Cartesian coordinate system shown in Fig. 1 is a convenient way to explain the positional relationships of the components. In Fig. 1 and other figures, for example, the positive direction of the Z axis is vertically upward, and the XY plane is a horizontal plane, which is common to all figures.

[0018] The steel plate member shown in FIG. 1 includes a first steel plate 10 and a second steel plate 20 . As shown in Fig. 1, through holes 11a and 11b are formed in a first steel plate 10. Cylindrical burred portions 12a and 12b extend upward (in the positive direction of the Z axis) from the periphery of each of the through holes 11a and 11b. Bolts B1 and B2 are inserted into the burred portions 12a and 12b, respectively, and fastened to other members (not shown).

[0019] The through holes 11a and 11b are formed, for example, by punching the first steel plate 10. The burred portions 12a and 12b are formed by induction heating the peripheral portions of the through holes 11a and 11b, respectively, to remove distortion, and then burring the peripheral portions.

[0020] Here, the burred portions 12a, 12b may be elongated by repeatedly performing induction heating and burring on the peripheral portions of the through holes 11a, 11b. This can prevent cracks and other problems that may occur during the burring process. Alternatively, the peripheral portions of the through holes 11a, 11b may be induction heated by inserting a cylindrical induction heating coil into the through holes 11a, 11b. This simple configuration allows the peripheral portions of the through holes 11a, 11b to be effectively heated. The heating conditions are, for example, a heating temperature of approximately 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 burred portions 12a, 12b side of the first steel plate 10. Through holes 21a, 21b for passing bolts B1, B2 are provided in the second steel plate 20 at locations facing the burred portions 12a, 12b of the first steel plate 10. The through holes 21a, 21b are formed by punching the second steel plate 20, for example.

[0022] As shown in Figure 1, when the steel plate member is fastened to another member by a bolt B1 through the through hole 11a of the first steel plate 10 and the through hole 21a of the second steel plate 20, the tip of the burring portion 12a of the first steel plate 10 abuts against the second steel plate 20 to support the bolt B1.

[0023] Similarly, when the steel plate member is fastened to another member by bolt B2 through the through hole 11b of the first steel plate 10 and the through hole 21b of the second steel plate 20, the tip of the burring portion 12b of the first steel plate 10 abuts against the second steel plate to support the bolt B2.

[0024] Although the bolts B1 and B2 shown in FIG. 1 are inserted from the second steel plate 20 side via washers W1 and W2, they may be inserted from the first steel plate 10 side. Furthermore, the number and arrangement of the through holes and burring portions for bolt fastening are not limited in any way and may be determined appropriately.

[0025] 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 440 MPa or more. As shown in Fig. 1, 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 (X-axis direction). Both widthwise ends of the first steel plate 10 and the second steel plate 20 are welded together. That is, the steel plate member is a rectangular tubular member.

[0026] 1, 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.

[0027] Here, FIG. 2 is a cross-sectional view of a steel plate member according to a comparative example. As shown in Fig. 2, in the steel plate member according to the comparative example, pipes P1 and P2 are welded to the periphery of each of through holes 11a and 11b in a first steel plate 10. More specifically, as shown in Fig. 2, the roots of the pipes P1 and P2 are welded to the first steel plate 10 at welds WP1 and WP2 that are annular in plan view.

[0028] As shown in Figure 2, when the steel plate member is fastened to another member by a bolt B1 through the through hole 11a of the first steel plate 10 and the through hole 21a of the second steel plate 20, the tip of the pipe P1 abuts against the second steel plate 20 to support the bolt B1.

[0029] Similarly, when the steel plate member is fastened to another member by bolt B2 through the through hole 11b of the first steel plate 10 and the through hole 21b of the second steel plate 20, the tip of pipe P2 abuts against the second steel plate to support bolt B2.

[0030] Here, the steel plate member according to the comparative example shown in FIG. 2 has the problem that it takes time and effort to align the welding positions of the pipes P1 and P2, and welding defects may occur at the welded portions WP1 and WP2.

[0031] In contrast, in the steel plate member according to this embodiment shown in FIG. 1, deformation of the first steel plate 10 and the second steel plate 20 due to bolt fastening can be suppressed by the burring portions 12a and 12b formed by burring processing, rather than by the welded pipes P1 and P2 shown in FIG. 2.

[0032] As described above, in the steel plate member according to this embodiment, when the steel plate member is fastened to another member by the bolts B1 and B2, the burring portions 12a and 12b of the first steel plate 10 come into contact with the second steel plate 20 to support the bolts B1 and B2. Therefore, deformation of the first steel plate 10 and the second steel plate 20 (i.e., the steel plate members) due to bolt fastening can be suppressed.

[0033] In this way, in the steel plate member according to this embodiment, the burred portions 12a, 12b formed by burring processing, rather than by welded pipes, can suppress deformation of the steel plate member due to bolt fastening.

[0034] <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. 3 and Fig. 4. Fig. 3 is a flowchart showing the method for manufacturing a steel plate member according to the first embodiment. Fig. 4 is a cross-sectional view showing the method for manufacturing a steel plate member according to the first embodiment.

[0035] First, as shown in FIGS. 3 and 4, the peripheral portions of the through holes 11a and 11b formed in the first steel plate 10 are induction heated, and then burred to form the burred portions 12a and 12b (step ST1).

[0036] For example, a cylindrical induction heating coil is inserted into the through holes 11 a and 11 b, and the peripheral portions of the through holes 11 a and 11 b are induction heated to remove distortion, and then the peripheral portions are burred. The induction heating of the peripheral portions and the burring process may be repeated to elongate the burred portions. On the other hand, through holes 21a and 21b are provided in the second steel plate 20 at locations facing the burred portions 12a and 12b.

[0037] 3 and 4, the first steel plate 10 and the second steel plate 20 are welded together while facing each other with the burring portions 12a, 12b facing inward (step ST2). More specifically, as shown in Fig. 4, both ends in the width direction (X-axis direction) of the first steel plate 10 and the second steel plate 20 are welded together to form a tubular steel plate member.

[0038] 1, when the steel plate member manufactured in this manner is fastened to another member with bolts B1 and B2, the burred portions 12a and 12b of the first steel plate 10 come into contact with the second steel plate 20 to support the bolts B1 and B2. Therefore, deformation of the first steel plate 10 and the second steel plate 20 (i.e., the steel plate members) due to bolt fastening can be suppressed.

[0039] In this way, by using the method for manufacturing a steel plate member according to this embodiment, the burred portions 12a, 12b are formed by burring rather than pipe welding, and deformation of the steel plate member due to bolt fastening can be suppressed.

[0040] 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]

[0041] 10 First Steel Plate 11a, 11b through hole 12a, 12b Burring section 20 Second Steel Plate 21a, 21b through hole B1, B2 bolts P1, P2 pipes W1, W2 washers

Claims

1. a first steel plate having a through hole and a cylindrical burring portion rising from a peripheral portion of the through hole; A cylindrical steel plate member in which the first and second steel plates are welded together, comprising: a second steel plate arranged opposite the burring portion side of the first steel plate and having a through hole provided in a portion opposite the burring portion; When the first and second steel plates are fastened to another member by a bolt through the through holes of the first and second steel plates, the burring portion abuts against the second steel plate to support the bolt. Steel plate components.

2. The steel plate member is a suspension member. The steel plate member according to claim 1 .

3. 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 burred portion; and welding a second steel plate, which has a through hole formed in a portion facing the burring portion, to the first steel plate, with the burring portion facing inward, to form a tubular steel plate member. When the steel plate member is fastened to another member by a bolt through the through holes of the first and second steel plates, the burring portion abuts against the second steel plate to support the bolt. Manufacturing method of steel plate components.

4. In the step of forming the burring portion, The induction heating and burring of the peripheral portion are repeated to elongate the burred portion. The method for manufacturing a steel plate member according to claim 3 .

5. 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 claim 3 or 4.

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