US-12624759-B2 - Threaded fastener, and function addition member of threaded fastener

Abstract

To provide a screwing fastener that is capable of preventing damage to a function adding member when tightening, and is capable of maintaining suitable functions of the function adding member and a suitable fastened state. A screwing fastener includes a fastener main body 10, a screw portion 13 for tightening the fastener main body 10 to a fastened member 200, a flange portion 14 provided to the fastener main body 10, and a seal function adding member 20 (function adding member) that is provided to the flange portion 14, in which the seal function adding member 20 comes into contact with the fastened member when tightening. The seal function adding member 20 has at least a two-layer structure of a sliding portion 22 (first adding portion) that is in contact with the flange portion 14, and a seal portion 21 (second adding portion) that comes into contact with the fastened member 200.

Inventors

• Youichi MATSUEDA

Assignees

• TOPURA CO., LTD.

Dates

Publication Date

20260512

Application Date

20210916

Priority Date

20210601

Claims (6)

1. 1 . A screwing fastener, comprising: a fastener main body having a seat face; a screw portion for tightening the fastener main body to a fastened member; a flange portion provided to the fastener main body, the flange portion is provided with a flange main body and an annular protruding portion that protrudes outward from an outer circumference of the flange main body; and a function adding member that is mounted to the flange portion, the screwing fastener configured to be tightened with the function adding member configured to be compressed between the flange portion and the fastened member, wherein the function adding member has at least a two-layer structure of a first adding portion that includes a recessed portion configured to be fit with the annular protruding portion and having slidability, and a second adding portion that is configured to come into contact with the fastened member, wherein the first adding portion is rotationally slidably in contact with the flange portion.
2. 2 . The screwing fastener according to claim 1 , wherein the second adding portion is a seal portion that is configured to have a seal function and that is configured to be in close contact with the fastened member and sealing off fluid.
3. 3 . The screwing fastener according to claim 2 , wherein the function adding member protrudes from the seat face of the fastener main body.
4. 4 . The screwing fastener according to claim 1 , wherein at least one of the first adding portion and the second adding portion is an insulator that has an insulating function.
5. 5 . The screwing fastener according to claim 1 , wherein the function adding member is detachably attachable to the flange portion.
6. 6 . A function adding member of a screwing fastener, the function adding member configured to be attached to a flange portion of the screwing fastener, the flange portion is provided with a flange main body and an annular protruding portion that protrudes outward from an outer circumference of the flange main body, the function adding member comprising: at least a two-layer structure of a first adding portion that includes a recessed portion configured to be fit with the annular protruding portion and having slidability, and a second adding portion that is configured to come into contact with a fastened member, wherein the first adding portion is rotationally slidably in contact with the flange portion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Stage of International Application No. PCT/JP2021/034042, filed Sep. 16, 2021 (now WO 2022/254739 A1), which claims priority to Japanese Application No. 2021-092464, filed Jun. 1, 2021. The entire disclosures of each of the above applications are incorporated herein by reference. FIELD The present disclosure relates to a screwing fastener such as a bolt, a nut, or the like, and particularly relates to a screwing fastener provided with a function adding member that adds sealing functions or insulating functions, and the function adding member used with the screwing fastener. BACKGROUND A bolt such as described in PTL 1, for example, is conventionally known as this type of screwing fastener. That is to say, the bolt described in PTL 1 is made up of a bolt main body that has a screw portion (shaft portion), a head portion that is formed on an upper end portion of the screw portion, and a flange portion that is formed on a lower end portion of the head portion, and a ring-shaped member made of non-electroconductive resin (function adding member) that encapsulates an outer circumferential portion of the flange portion. The ring-shaped member made of resin is provided with an edge portion that is situated on a lower end side of the screw portion from a seat face and on an outer side of the flange main body portion, and an annular skirt portion that increases in diameter toward the edge portion. The annular skirt portion deforms so as to spread when being attached to an attachment object part for the bolt, thereby forming an annular liquid-tight seal portion with respect to the attachment object part. Also, PTL 2 applies a similar configuration to a nut as well. CITATION LIST Patent Literature [PTL 1] Japanese Patent No. 5145226[PTL 2] Japanese Patent No. 5276447 SUMMARY Technical Problem However, with the ring-shaped members made of resin for the bolt described in described in PTL 1 and the nut described in PTL 2 above, frictional force of the annular liquid-tight seal portion increases as tightening progresses, rotation of the annular liquid-tight seal portion is suppressed with respect to rotation of the flange portions of the bolt and the nut, and the ring-shaped member made of resin becomes greatly twisted in a circumferential direction between a portion of joining the flange portion and the annular liquid-tight seal portion. Accordingly, there have been problems such as a joining face that joins to the flange portion peeling away, or ruptures occurring in the ring-shaped member made of resin and tearing. Even if the joining face of the ring-shaped members made of resin does not peel away, deformation becomes great and the seal becomes defective. Also, due to the above phenomenon, fastening cannot be performed up to an axial force that is necessary for fastening, leading to defective fastening. Further, using a hard resin so as to not tear requires a high axial force, necessitating a high axial force to obtain the necessary axial force, consequently resulting in deformation and damage to the bolt due to insufficient bolt strength, and defective fastening. It is an object of the present disclosure to provide a screwing fastener with a function adding member, and the function adding member of the screwing fastener, which are capable of preventing damage to the function adding member when tightening, and capable of maintaining suitable functions of the function adding member and a suitable fastened state. Solution to Problem In order to achieve the above object, the present disclosure is a screwing fastener, including a fastener main body having a seat face, a screw portion for tightening the fastener main body to a fastened member, a flange portion provided to the fastener main body, and a function adding member that is provided to the flange portion, the screwing fastener being tightened with the function adding member being compressed between the flange portion and the fastened member. The function adding member has at least a two-layer structure of a first adding portion that is provided to the flange portion and has slidability, and a second adding portion that comes into contact with the fastened member. According to the present disclosure, as frictional force increases at a contact portion of the second adding portion and the fastened member when tightening, sliding occurs at an interface of the contact portion of the first adding portion and the flange portion, an interface of the contact portion of the first adding portion and the second adding portion, or the like, whereby excessive twisting can be suppressed from occurring at the second adding portion, and there is no concern of the second adding portion being damaged. Also, the contact portion of the first adding portion and the flange portion, and the contact faces of the second adding portion and the first adding portion, are sealed by the tightening force. The second adding por