WO2011089650A1

WO2011089650A1 - Fastener member and fastening structure

Info

Publication number: WO2011089650A1
Application number: PCT/JP2010/000368
Authority: WO
Inventors: 廣田秀行
Original assignee: 三菱電機株式会社
Priority date: 2010-01-22
Filing date: 2010-01-22
Publication date: 2011-07-28
Also published as: JPWO2011089650A1

Abstract

A fastener member has resilient legs (13a,13b) that are bent radially inwardly by latch portions (14a,14b) when the legs are inserted into through holes (21,31) and return to normal to engage the bottom edge of the hole (31) whereby fastening a circuit board (20) and a metal plate (30) between the legs and a top latch (11) when the legs go beyond the holes (21,31). To remove the fastener member (10), a tool is inserted in a hole (12) to bend the resilient legs (13a,13b) inwardly to disengage the latch portions (14a,14b).

Description

Fastening parts and fastening structure

The present invention relates to a fastening part for fastening a plurality of parts and a fastening structure for a plurality of parts using the fastening parts.

Threads are the main component for fastening multiple parts. However, for example, when a circuit board on which an electronic component is mounted and a sheet metal component are fastened with a screw, a threaded residue is generated, and the threaded residue comes into contact with the electronic component and often causes a short circuit. Therefore, in Patent Document 1, for example, a resin female screw is attached to a screw through hole of a sheet metal part, and a male screw is fastened thereto to suppress the occurrence of thread cutting residue.

JP 2008-42134 A

Since the conventional fastening structure uses a screw in any case, there is a problem that it is not possible to prevent the occurrence of threading scraps, and it is also impossible to prevent problems due to threading scraps. In addition, it took man-hours for assembly and further man-hours for disassembly.

The present invention has been made to solve the above-described problems, and provides a fastening part that can be easily and quickly fastened while preventing the occurrence of threading scraps, and a fastening structure using the fastening part. For the purpose.

The fastening component according to the present invention includes a pair of elastic legs inserted into the through-holes of the parts to be fastened, a bent portion having a shape in which each tip side of the pair of elastic legs is alternately bent inward, and an elastic leg. Retention protrusions that protrude from the outer surfaces of the holes, bend the elastic legs inward when inserted into the through holes, restore after passing through the through holes, and lock to the edges on the back side of the through holes And a hook portion that is formed on the base end side of the elastic leg portion and hooks on the edge on the surface side of the through hole and clamps the fastened component between the retaining protrusion.

The fastening structure of the present invention is to fasten a plurality of parts to be fastened using the fastening parts described above.

According to the fastening component of the present invention, when the pair of elastic leg portions are inserted into the through holes, the retaining protrusions bend the elastic leg portions inward, and are restored after passing through the through holes. Locked to the edge of the surface and configured to clamp the part to be fastened between the retaining protrusion and the hooking part, so it can be fastened without using a screw, preventing the generation of thread scraps be able to.

According to the fastening structure of the present invention, a plurality of parts to be fastened can be fastened easily and quickly by using the fastening parts described above.

It is an external appearance perspective view which shows the structure before the assembly | attachment with respect to the to-be-fastened component of the fastening component which concerns on Embodiment 1 of this invention. It is sectional drawing which cut | disconnected the fastening component before an assembly | attachment along the AA line shown in FIG. It is sectional drawing which cut | disconnected the fastening component after an assembly | attachment along the AA line shown in FIG. It is sectional drawing which cut | disconnected the fastening component made into the removal state along the AA line shown in FIG. FIG. 8 is a cross-sectional view showing a modification of the fastening component according to Embodiment 1 and cut at a position corresponding to the AA line shown in FIG. 1. FIG. 8 is a cross-sectional view showing a modification of the fastening component according to Embodiment 1 and cut at a position corresponding to the AA line shown in FIG. 1.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is an exploded perspective view showing a circuit board 20 and a sheet metal part 30 which are parts to be fastened, and a fastening part 10 to be assembled to a through hole 21 and a through hole 31 which are respectively drilled. 2 to 4 are cross-sectional views cut along the line.

A fastening part 10 made of resin such as polyacetal (POM) and having elasticity is provided on the back side of the sheet metal part 30 through a hooking part 11 that is hooked on the front side of the circuit board 20 and through

holes

21 and 31. It is comprised from a pair of

elastic leg part

13a, 13b which penetrates. In the middle of these

elastic leg portions

13a and 13b, retaining

projections

14a and 14b that are caught on the edge of the back surface of the through hole 31 are formed. The upper and lower sides of the

retaining protrusions

14a, 14b are

tapered surfaces

16a, 16b, 17a, 17b. Further, the ends of the

elastic legs

13a and 13b are bent inward to form the

bent portions

15a and 15b. The

elastic legs

13a and 13b have the same shape as each other. However, since one of them is inverted and shifted, the

bent portions

15a and 15b do not come into contact with each other and are alternated.
Further, a jig insertion hole 12 for inserting a jig for releasing the fastening of the fastening component 10 is formed in the hook portion 11.

The sheet metal part 30 is subjected to burring processing (processing to open a hole and raise its periphery) or bending to form a through hole 31, and the edge of the entrance portion is formed into a curved surface 32. This is to prevent the fastening component 10 from being scraped in contact with the sheet metal edge. Since one circuit board 20 uses a resin substrate, the edge of the through hole 21 does not have to be a curved surface.

As shown in FIG. 2, when the fastening part 10 is assembled to the circuit board 20 and the sheet metal part 30, the

elastic legs

13a and 13b of the fastening part 10 are pushed into the through holes 21 of the circuit board 20. At this time, since the

taper surfaces

17a and 17b enter while abutting against the inlet portion of the through hole 21, the

elastic leg portions

13a and 13b automatically bend inward. Moreover, since the entrance part of the through-hole 31 is the curved surface 32, the

elastic leg parts

13a and 13b are not caught, and the resin fastening parts 10 are not scraped to the sheet metal edge.

As shown in FIG. 3, when the

retaining protrusions

14a and 14b pass through the through hole 31 and come out to the back side of the sheet metal part 30, the bent

elastic legs

13a and 13b return to their original shapes. Therefore, the

retaining projections

14a and 14b are locked to the edge of the through hole 31 to prevent the fastening component 10 from being detached, and the circuit board 20 and the sheet metal component 30 are interposed between the hook portion 11 and the

retaining projections

14a and 14b. Tighten it in between. At this time, since the surfaces of the

retaining projections

14a and 14b that contact the sheet metal part 30 are tapered

surfaces

16a and 16b, the thicknesses of the circuit board 20 and the sheet metal part 30 and the hole diameters of the through holes 31 vary. Can also be securely locked.

As shown in FIG. 4, when disassembling the fastening structure, the jig 40 is inserted from the jig insertion hole 12 of the fastening part 10 and the

bent portions

15a and 15b are pushed. Then, since the

elastic leg portions

13a and 13b bend inward, the

locking projections

14a and 14b and the through hole 31 are unlocked, and the fastening component 10 can be removed.
Since the jig 40 does not require a special structure, a minus driver or the like can be used.

Alternatively, from the back side of the sheet metal part 30, the

elastic surfaces

13a and 13b are bent inward by picking the

tapered surfaces

17a and 17b with a finger or pushing them with the cylindrical jig 41, and removing the fastening part 10 May be. In this case, it is not necessary to provide the jig insertion hole 12.

As described above, according to the first embodiment, the fastening component 10 includes the pair of

elastic leg portions

13a and 13b inserted into the through

holes

21 and 31 of the circuit board 20 and the sheet metal component 30, and the pair of

elastic leg portions

13a and 13a. 13b protrudes on the outer surfaces of the

bent portions

15a and 15b and the

elastic leg portions

13a and 13b, each of which is alternately bent inward, and is elastic when inserted into the through

holes

21 and 31.

Detachment protrusions

14a and 14b that bend the

leg portions

13a and 13b inward, restore after passing through the through

holes

21 and 31 and engage with the edge on the back side of the through hole 31, and

elastic leg portions

13a and 13b. A hook portion 11 is formed on the base end side and hooked to the edge on the surface side of the through hole 21 to hold the circuit board 20 and the sheet metal part 30 between the

retaining projections

14a and 14b. did. For this reason, since no screw is used, thread scraps do not occur, and problems due to thread scraps can be prevented. Further, the circuit board 20 and the sheet metal part 30 can be easily fastened simply by pushing the fastening part 10 into the through

holes

21 and 31.

Further, according to the first embodiment, the

elastic legs

13a and 13b are provided with the

tapered surfaces

17a and 17b whose outer surfaces on the distal end side with respect to the

retaining projections

14a and 14b are inclined inward toward the distal ends. It was. For this reason, when the

elastic leg portions

13a and 13b are pushed into the through

holes

21 and 31, the

tapered surfaces

17a and 17b enter while abutting against the inlet portion of the through hole 21, so that the

elastic leg portions

13a and 13b automatically move. Bends and becomes easy to push.

Further, according to the first embodiment, the

bent portions

15a and 15b are pressed against the hooking portion 11 from the hooking portion 11 side to bend the

elastic leg portions

13a and 13b inward, and the retaining protrusion 14a. 14b and the through

holes

21 and 31 are provided with a jig insertion hole 12 for inserting a jig 40 for releasing the locking. For this reason, the fastening component 10 can be easily removed simply by inserting the jig 40.

Further, according to the first embodiment, the through hole 31 of the sheet metal part 30 is configured to be formed by burring or bending. For this reason, since the entrance part of the through-hole 31 becomes the curved surface 32, when inserting the

elastic leg parts

13a and 13b, the catch to a sheet metal edge can be eliminated.

In the illustrated example of the first embodiment, the curved surface 32 is formed only in the through hole 31 of the sheet metal part 30. However, the present invention is not limited to this, and the curved surface is also formed in the through hole 21 of the circuit board 20. Also good. By making the entrance part of the through hole 21 into a curved surface, it becomes easier to push the fastening part 10 into the through hole 21.
The through hole 31 may be formed by a method other than burring or bending, and the curved surface 32 may not be formed.

In addition, although the through hole 21 is rectangular, it is not limited to this, and may be any shape such as circular. Although the through-hole 31 is also rectangular, it is sufficient that the two sides for locking the retaining

protrusions

14a and 14b of the fastening part 10 have at least a linear shape, for example, a long hole in which the remaining two sides have an arc shape.

In addition, the fastening part 10 is configured to fasten two fastening parts. However, the fastening part 10 is not limited to this, and the length of the

elastic legs

13a and 13b is adjusted so that three or more fastening parts are provided. You may fasten. In addition, when the length of the

elastic leg portions

13a and 13b is extremely short, there is a risk of breaking when bent inward. Therefore, when the thickness of the component to be fastened is thin, the rising portion of the peripheral edge may be lengthened when burring the through hole 31.

Further, the fastening part 10 may be modified as shown in FIGS. The fastening component 10 shown in FIG. 5 has a shape in which the ends of the

elastic legs

13a and 13b are opened outward. Moreover, the fastening component 10 shown in FIG. 6 is the shape which extended the outer surface of the

elastic leg parts

13a and 13b toward the front-end | tip. In both shapes of the fastening component 10, the outer surfaces from the base end sides of the

elastic leg portions

13a and 13b to the retaining

projections

14a and 14b are inclined outward toward the tip, so that the

elastic leg portions

13a and 13b. Are assembled to the through

holes

21 and 31 so as to be compressed. Then, the circuit board 20 and the sheet metal part 30 sandwiched between the hook portion 11 and the retaining

projections

14a and 14b are always loaded in the sandwiching direction by the restoring force of the

elastic legs

13a and 13b. Therefore, the fastening part 10 having the shape shown in FIGS. 5 and 6 has a fastening force improved as compared with the fastening part 10 having the shape shown in the first embodiment.

As described above, since the fastening part according to the present invention is pushed into the through hole of the part to be fastened instead of the screw, it is used for a fastening structure for fastening the circuit board on which the electronic part is mounted to the sheet metal part. Suitable for

Claims

A pair of elastic legs inserted into the through-holes of the parts to be fastened;
A bent portion having a shape in which the distal ends of the pair of elastic legs are alternately bent inward;
Projecting on the outer surface of each of the elastic legs, the elastic legs are deflected inward when inserted into the through hole, and restored after passing through the through hole. Retaining protrusions that lock to the edges,
A fastening part comprising: a hook part that is formed on a base end side of the elastic leg part and is hooked on a surface side edge of the through hole and sandwiches the fastened part between the retaining protrusion.
The fastening part according to claim 1, wherein the elastic leg portion is a tapered surface whose outer surface on the tip side from the retaining protrusion is inclined inward toward the tip.
The hooking part has a jig insertion hole for inserting a jig that releases the locking protrusion and the through hole by bending the elastic leg part inward by pressing the bent part from the hooking part side. The fastening part according to claim 1, further comprising:
The fastening part according to claim 1, wherein the elastic leg portion has a shape in which an outer surface from the base end side to the retaining protrusion is inclined outward toward the tip.
In a fastening structure for fastening a plurality of parts to be fastened using fastening parts,
The fastening part is
A pair of elastic legs inserted into the through-holes of the fastened parts;
A bent portion having a shape in which the distal ends of the pair of elastic legs are alternately bent inward;
Projecting on the outer surface of each of the elastic legs, the elastic legs are deflected inward when inserted into the through hole, and restored after passing through the through hole. Retaining protrusions that lock to the edges,
A hook portion that is formed on a base end side of the elastic leg portion and is hooked to an edge on a surface side of the through hole and sandwiches the fastened part between the retaining protrusion and the hook portion. Fastening structure to do.
The fastening structure according to claim 5, wherein the through hole of the part to be fastened is formed by burring or bending.
6. The fastening structure according to claim 5, wherein the elastic leg portion of the fastening part is a taper surface whose outer surface on the tip side from the retaining protrusion is inclined inward toward the tip.
The hook part of the fastening part is a jig that inserts a jig that presses the bent part from the hook part side to bend the elastic leg part inward, and releases the locking of the retaining protrusion and the through hole. The fastening structure according to claim 5, further comprising an insertion hole.
6. The fastening structure according to claim 5, wherein the elastic leg portion of the fastening part has a shape in which an outer surface from the base end side to the retaining projection is inclined outward toward the tip.