Screw member

Abstract

A bolt (100) is provided with a screw part, a screw head part (20), and a flange part (30) that is provided between the screw head part (20) and the screw part (10) and that projects annularly with respect to the screw head part (20). The bolt (100) is provided between the flange part (30) and the screw part (20), has a fastening surface (S2) in contact with a fastened member (200), and is provided with a fastening part (40) having a smaller diameter than the flange part (30). In a state in which the fastening surface (S2) of the bolt (100) is in contact with the fastened member (200), a space (A1) is formed between the fastened member (200) and the flange part (30).

Description

Screw material CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-44320 filed in Japan on March 20, 2024, the contents of which are incorporated by reference in their entirety.

[0002] The present disclosure relates to a screw member.

[0003] An example of a screw member is the bolt disclosed in Patent Document 1. The bolt in Patent Document 1 has a pressing surface formed around the bearing surface of the head, which is recessed from the bearing surface by a step. The bolt also has an annular portion formed from the periphery of the bearing surface to the tip of the flange portion so as to cover the pressing surface.

[0004] JP 2010-133446 A

[0005] The bolt in Patent Document 1 has an annular member, which increases the number of parts and manufacturing steps. Incidentally, a screw member may have a head, a flange that protrudes annularly from the head, and a threaded portion that protrudes from the flange. The surface of the flange facing the threaded portion serves as the fastening surface that contacts the fastened members.

[0006] However, the flange of the screw member may be deformed due to dents made during the manufacturing process. Furthermore, the deformation of the flange may form a protrusion on the fastening surface of the screw member. Therefore, there is a risk that the screw member may damage the fastened member with the protrusion.

[0007] One disclosed object is to provide a screw device that can reduce damage to fastened members.

[0008] The screw member disclosed herein comprises a threaded portion, a screw head, a flange portion provided between the screw head and the threaded portion and protruding annularly from the screw head, and a fastening portion provided between the flange portion and the threaded portion, having a fastening surface that contacts the fastened member and has a smaller diameter than the flange portion, and when the fastening surface is in contact with the fastened member, a space is formed between the fastened member and the flange portion.

[0009] In this way, the screw member has a flange portion and a fastening portion. That is, the flange portion is provided to protrude further than the fastening portion. Therefore, in the manufacturing process of the screw member, a protrusion is more likely to be formed on the flange portion than on the fastening portion.

[0010] Furthermore, when the fastening surface of the screw member is in contact with the fastened member, a space is formed between the fastened member and the flange portion. Therefore, even if a protrusion is formed on the flange portion of the screw member, the protrusion can be prevented from contacting the fastened member. Therefore, the screw member can reduce damage to the fastened member.

[0011] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify correspondences with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings.

[0012] Fig. 2 is a plan view showing a schematic configuration of a bolt. Fig. 3 is a plan view from the direction of arrow II in Fig. 1. Fig. 4 is a cross-sectional view taken along line III-III in Fig. 1. Fig. 5 is a plan view showing the bolt attached to fastened members. Fig. 6 is a plan view showing the bolt in contact with equipment. Fig. 7 is an enlarged plan view showing the end of the bolt. Fig. 8 is an enlarged plan view showing the screw head, flange portion, and fastening portion.

[0013] Hereinafter, an embodiment of the present disclosure will be described with reference to Figures 1 to 7. In this embodiment, an example is adopted in which the threaded member is applied to a bolt 100. However, the threaded member may also be applied to a screw.

[0014] 1 and 2, the bolt 100 includes a threaded portion 10, a screw head 20, a flange portion 30, and a fastening portion 40. The bolt 100 is made primarily of metal, for example. The bolt 100 can also be called a flange bolt.

[0015] As shown in Figure 4, the bolt 100 fastens the fastened members 200. In other words, the bolt 100 fastens the fastened members 200 to an object. The male thread 11 of the bolt 100 is fitted into the female threads of the fastened members 200 and the object.

[0016] The state in which the male thread 11 is fitted into the female thread is also referred to as a screw-fastened state. In the screw-fastened state, the bolt 100 fastens the fastened member 200 to the object. The screw-fastened state can also be called a fastening state. The screw-fastened state can also be called a state in which the fastening surface S2, which will be described later, is in contact with the fastened member 200. The fastened member 200 may also be provided with a through-hole into which the threaded portion 10 is inserted instead of a female thread. The components of the bolt 100, such as the threaded portion 10 and the male thread 11, will be described in detail later.

[0017] The fastened member 200 may be, for example, a circuit board or a bus bar. A circuit board is a printed circuit board on which circuit elements such as semiconductor switches are mounted. The circuit board is attached to a case or the like. Thus, the bolt 100 fastens the circuit board, which is the fastened member 200, to the case, which is the target object.

[0018] The bus bar is a conductive plate member. Some bus bars have a plated surface. The bus bar is attached to a terminal or the like. Thus, the bolt 100 fastens the bus bar as the fastened member 200 to the terminal as the target object. The terminal may be a terminal of an inverter circuit, a terminal of a capacitor, a terminal of a motor, or the like. However, the fastened member 200 is not limited to these.

[0019] The bolt 100 and the fastened member 200 into which the bolt 100 is fitted can also be called a screw-fastening structure. That is, the screw-fastening structure includes the bolt 100 described below and the fastened member 200 provided with a female thread. The screw-fastening structure may also include an object.

[0020] Furthermore, the bolt 100 may be fitted into a nut provided with an internal thread. In this case, the fastened member 200 and the target object only need to be provided with a through-hole into which the threaded portion 10 of the bolt 100 is inserted. The fastened member 200 and the target object are then fastened together while sandwiched between the fastening portion 40 of the bolt 100 and the nut.

[0021] Here, the respective portions 10 to 40 of the bolt 100 will be described. The threaded portion 10, the screw head 20, the flange portion 30, and the fastening portion 40 are configured as a single unit. For example, the threaded portion 10, the screw head 20, the flange portion 30, and the fastening portion 40 all have the same central axis. The bolt 100 is provided with the threaded portion 10, the fastening portion 40, the flange portion 30, and the screw head 20 in this order. The central axis coincides with the arrangement direction of the respective portions 10 to 40.

[0022] 1, the threaded portion 10 is a rod-shaped portion that is provided linearly. The threaded portion 10 has a male thread 11 provided on at least a portion thereof. The threaded portion 10 has a cylindrical shape, and it can also be said that the male thread 11 is provided on the surface.

[0023] 1 and 2, the screw head 20 is a portion that protrudes from a flange portion 30 (described later) on the opposite side from the threaded portion 10. The screw head 20 is provided with a recess 21 into which the tip of a screwdriver or the like is inserted. In this embodiment, as an example, a screw head 20 provided with a cross-shaped (x-shaped) recess 21 is used. The recess 21 can also be called a recess.

[0024] 1 and 2, the flange portion 30 is provided between the screw head 20 and the threaded portion 10. The flange portion 30 is provided so as to protrude in an annular shape from the screw head 20. In other words, the flange portion 30 can also be said to be an annular portion. When the bolt 100 is viewed from the screw head 20 side, the flange portion 30 is provided around the screw head 20.

[0025] As shown in Fig. 4, the flange portion 30 has an opposing surface S1 that faces a fastened surface S3, which is the surface of the workpiece 200, when the screw is fastened. However, the opposing surface S1 does not contact the fastened surface S3 when the screw is fastened. Furthermore, when the screw is fastened, a space A1 is formed between the opposing surface S1 and the fastened surface S3. The opposing surface S1 is the surface opposite the screw head 20. As shown in Fig. 3, the opposing surface S1 is annular.

[0026] As shown in Figures 1, 6, etc., the corners 31 of the flange portion 30 have a rounded shape. The corners 31 can also be said to be R-chamfered. Therefore, the corners 31 can also be said to be rounded portions. The flange portion 30 is R-chamfered around the entire periphery. However, the present disclosure is not limited to this. The corners 31 may be provided at right angles. Furthermore, the corners 31 may be C-chamfered. The corners 31 are portions that connect to the opposing surface S1. Furthermore, the corners 31 are end portions of the flange portion 30. The corners 31 correspond to the first end portion.

[0027] 1 and 2, the fastening portion 40 is provided between the flange portion 30 and the threaded portion 10. The fastening portion 40 is a portion that protrudes from the flange portion 30 (opposing surface S1) on the side opposite to the screw head 20. In other words, the fastening portion 40 is a portion that protrudes toward the threaded portion 10 side relative to the opposing surface S1.

[0028] The fastening portion 40 is a portion that comes into contact with the fastened member 200 when fastened with the screw. The fastening portion 40 is also a portion that presses the fastened member 200 when fastened with the screw. Therefore, the fastening portion 40 can also be called a pressing portion.

[0029] The fastening portion 40 has a smaller diameter than the flange portion 30. Therefore, a step is formed between the fastening portion 40 and the flange portion 30 of the bolt 100. In other words, the fastening surface S2, which will be described later, is positioned in a different position in the central axis direction from the opposing surface S1. Therefore, the flange portion 30 and the fastening portion 40 together can be called a stepped flange.

[0030] The fastening portion 40 has a fastening surface S2 that contacts the fastened surface S3 when screwed. The fastening surface S2 is the surface opposite to the screw head 20. As shown in FIG. 3 , the fastening surface S2 is annular. The fastening surface S2 is a surface that presses against the fastened member 200. Therefore, the fastening surface S2 can also be called a contact surface or a pressing surface. The threaded portion 10 is provided so as to protrude from the fastening surface S2.

[0031] As described above, the fastening surface S2 contacts the fastened member 200. Therefore, it is desirable that the fastening portion 40 does not have any portions (protrusions) that protrude beyond the fastening surface S2. The protrusions here can be referred to as burrs or scuff marks. The protrusions are not intentionally provided. They are formed as a result of dents made during the manufacturing process of the bolt 100. The male thread 11 of the bolt 100 is formed by the rolling process. After the rolling process is completed, the bolt 100 scatters into the surrounding area. At that time, the bolt 100 collides with other bolts 100, the manufacturing equipment 300, etc. Protrusions are formed on the bolt 100 due to this collision. Hereinafter, protrusions will be referred to as scuff marks.

[0032] The fastening portion 40 is preferably provided so as not to form burrs even when it collides with the manufacturing equipment 300. Fig. 5 shows a state in which the bolt 100 has collided with the equipment surface S4 of the manufacturing equipment 300. The equipment surface S4 is assumed to be a flat surface.

[0033] Therefore, it is preferable that the fastening portion 40 be located at a position that does not contact the imaginary line connecting the corner 31 of the flange portion 30 and the tip corner 12, which is the end of the threaded portion 10. As a result, when the bolt 100 collides with the equipment surface S4, the corner 31 and the tip corner 12 come into contact with the equipment surface S4. In other words, the fastening portion 40 does not come into contact with the equipment surface S4. Therefore, even when the bolt 100 collides with the equipment surface S4, the formation of burrs in the fastening portion 40 can be suppressed. In other words, the bolt 100 is configured so that burrs are formed in the flange portion 30, not in the fastening portion 40, when it collides with the equipment surface S4.

[0034] The straight line along the equipment surface S4 can be regarded as a virtual straight line. The tip corner 12 corresponds to the second end.

[0035] The size of the dents on the bolt 100 varies depending on the mass of the bolt 100 and the speed at which the bolt 100 is discharged during the rolling process. Therefore, it is preferable that the thickness T1 of the flange portion 30 and the thickness T2 of the fastening portion 40 be set to values ​​that prevent burrs from interfering with the fastened surface S3 through analysis and actual machine confirmation.

[0036] For example, thicknesses T1 and T2 are set so as to make it difficult for burrs to form in the fastening portion 40. As shown in FIG. 6 , thickness T1 of flange portion 30 is preferably thicker than thickness T2 of fastening portion 40. This makes it difficult for fastening portion 40 to come into contact with an imaginary line. Therefore, even if bolt 100 collides with equipment surface S4, it is possible to prevent burrs from forming in fastening portion 40. Note that bolt 100 with this thickness relationship can also be said to have a thin structure in which thickness T2 of fastening portion 40 is thin. However, the present disclosure is not limited to this.

[0037] Alternatively, the thicknesses T1 and T2 may be set so that burrs formed on the flange portion 30 are less likely to protrude beyond the fastening surface S2 when the screws are fastened. For example, the thickness T2 of the fastening portion 40 is made thicker than the thickness T1 of the flange portion 30. Alternatively, the thickness T2 of the fastening portion 40 is made equal to the thickness T1 of the flange portion 30. This is preferable because it makes it less likely that burrs formed on the flange portion 30 will protrude beyond the fastening surface S2 than in the case of a thin structure.

[0038] As shown in Figures 1, 6, etc., the corners 41 of the fastening portion 40 have a rounded shape. The corners 41 can also be said to be R-chamfered. The fastening portion 40 is R-chamfered around the entire periphery. However, the present disclosure is not limited to this. The corners 41 may be provided at right angles. The corners 41 may also be C-chamfered. The corners 41 are portions that connect to the fastening surface S2.

[0039] 1, 6, etc., the side wall 42 of the fastening portion 40 has a tapered shape. That is, the cross-sectional area of ​​the fastening portion 40 gradually narrows from the flange portion 30 side toward the threaded portion 10 side. In other words, the side wall 42 is inclined so that the angle it forms with the opposing surface S1 is an obtuse angle. The cross-sectional area here is the area of ​​a cross section perpendicular to the central axis.

[0040] This further reduces the formation of burrs in the fastening portion 40 even when the bolt 100 hits the equipment surface S4. In other words, the bolt 100 can reduce the formation of burrs more effectively than a configuration in which the side wall 42 does not have a tapered shape. However, the side wall 42 does not have to have a tapered shape.

[0041] 7, the relationship between the diameter D1 of the flange portion 30, the diameter D2 of the fastening portion 40, and the diameter D3 of the screw head 20 is preferably D1 > D2 ≥ D3. This makes it easier for the bolt 100 to ensure axial tension.

[0042] <Effects> As described above, the bolt 100 includes the flange portion 30 and the fastening portion 40. In other words, the flange portion 30 is provided to protrude further than the fastening portion 40. Therefore, in the bolt 100, burrs are more likely to form in the flange portion 30 than in the fastening portion 40 during the manufacturing process.

[0043] Furthermore, the bolt 100 has a step formed between the flange portion 30 and the fastening portion 40. Therefore, as shown in Fig. 4, when the bolt 100 is screwed, a space A1 is formed between the fastened member 200 and the flange portion 30. In other words, the bolt 100 has a gap between the opposing surface S1 and the fastened surface S3. For example, it is preferable that the space A1 be formed even when the fastening portion 40 of the bolt 100 is partially embedded in the fastened member 200.

[0044] Therefore, even if burrs are formed on the flange portion 30, the bolt 100 can prevent the burrs from coming into contact with the fastened members 200. Therefore, the bolt 100 can reduce damage to the fastened members 200. The bolt 100 can also reduce the generation of shavings that accompany damage to the fastened members 200. Furthermore, the bolt 100 can be used without changing the conditions of the existing manufacturing process.

[0045] However, circuit boards and bus bars serving as fastened components 200 may be damaged by burrs on the bolt 100, and shavings may be generated as a result of the damage. The shavings may adhere to the circuit board, inverter circuit, or the like, and cause electrical malfunctions. In other words, damage to the fastened components 200 and the generation of shavings associated with the damage are undesirable. However, the bolt 100 can reduce the generation of shavings as described above. Therefore, the bolt 100 is suitable for fastening circuit boards and bus bars.

[0046] Furthermore, the corners 31 of the flange portion 30 are rounded. Therefore, even if the manufacturing equipment 300 or the like collides with the rounded corners 31 of the bolt 100, the bolt 100 can more easily absorb the impact than a configuration in which the corners 31 are not rounded. Furthermore, it can be said that even if the manufacturing equipment 300 or the like collides with the rounded corners 31 of the bolt 100, the bolt 100's behavior is more likely to change along the rounded shape. In other words, the bolt 100 can reduce the impact on the rounded corners 31. Therefore, even if burrs are formed on the corners 31 of the bolt 100, the burrs can be smaller than a configuration in which the corners 31 are not rounded.

[0047] Furthermore, the corners 41 of the fastening portion 40 are rounded. Therefore, for the same reason as the flange portion 30, the bolt 100 can reduce burrs formed on the fastening portion 40.

[0048] The present disclosure has been described with reference to the embodiments. However, the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and spirit of the present disclosure.

[0049] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0050] (Technical Idea 1) A screw member comprising: a threaded portion (10); a screw head (20); a flange portion (30) provided between the screw head and the threaded portion and protruding annularly relative to the screw head; and a fastening portion (40) provided between the flange portion and the threaded portion, having a fastening surface (S2) that contacts a fastened member (200) and has a diameter smaller than that of the flange portion, wherein when the fastening surface is in contact with the fastened member, a space is formed between the fastened member and the flange portion.

[0051] (Technical Idea 2) A screw member according to Technical Idea 1, wherein the fastening portion is provided at a position that does not touch an imaginary line connecting a first end (31) that is an end of the flange portion and a second end (12) that is an end of the threaded portion.

[0052] (Technical Concept 3) The screw member according to Technical Concept 1 or 2, wherein the thickness (T1) of the flange portion is greater than the thickness (T2) of the fastening portion.

[0053] (Technical Concept 4) A screw member according to any one of Technical Concepts 1 to 3, wherein the side wall (42) of the fastening portion has a tapered shape.

[0054] (Technical Idea 5) A screw member according to any one of Technical Ideas 1 to 4, wherein the relationship between the diameter (D1) of the flange portion, the diameter (D2) of the fastening portion, and the diameter (D3) of the screw head is D1>D2≧D3.

[0055] (Technical Concept 6) A screw member according to any one of Technical Concepts 1 to 5, wherein the corners (31) of the flange portion have a rounded shape.

[0056] (Technical Concept 7) A screw member according to any one of Technical Concepts 1 to 6, wherein the corners (41) of the fastening portion have a rounded shape.

Claims

1. A screw member comprising: a threaded portion (10); a screw head (20); a flange portion (30) provided between the screw head and the threaded portion and projecting annularly relative to the screw head; and a fastening portion (40) provided between the flange portion and the threaded portion, having a fastening surface (S2) that contacts a fastened member (200) and has a diameter smaller than that of the flange portion, wherein when the fastening surface is in contact with the fastened member, a space is formed between the fastened member and the flange portion.

2. A screw member as described in claim 1, wherein the fastening portion is provided at a position that does not touch an imaginary line connecting a first end (31) which is the end of the flange portion and a second end (12) which is the end of the threaded portion.

3. A screw member according to claim 1 or 2, wherein the thickness (T1) of the flange portion is greater than the thickness (T2) of the fastening portion.

4. A screw member according to claim 1 or 2, wherein the side wall (42) of the fastening portion has a tapered shape.

5. A screw member according to claim 1 or 2, wherein the relationship between the diameter (D1) of the flange portion, the diameter (D2) of the fastening portion, and the diameter (D3) of the screw head is D1 > D2 ≥ D3.

6. A screw member according to claim 1 or 2, wherein the corners (31) of the flange portion are rounded.

7. A screw member according to claim 1 or 2, wherein the corners (41) of the fastening portion are rounded.

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