JP2001099117A - Fastening tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved fastening tool having a high mounting workability and retaining force and a high demounting workability. SOLUTION: This is a fastening tool 1 comprising a grommet 2 having a cylindrical part 6 whose both ends are opened axially by the provision of a through hole (female screw hole 4), an axially cut division part 7 formed from one end side of the cylindrical part and a flange formed at the other end of the cylindrical part 6, and a pin 3 to be inserted into the through hole so as to enlarge one end side of the cylindrical part. In the tool 1, a large diameter part 9 than the inner diameter of the through hole is formed at one end of the pin 3, and the pin inserted into the through hole is axially moved in the direction so as to be pulled out from the side of a flange to thereby outwardly push and open the one end side of the cylindrical part. Accordingly, the other end of the pin projecting from the side of flange is striken to thereby push the large diameter part out, resulting in easy releasing of fastening condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastener for fixing a plurality of plate-like members to each other in a state of being overlapped.

[0002]

2. Description of the Related Art For example, when a plurality of plate members are overlapped and fixed to each other as in the case where a washer liquid tank or an air duct assembly is attached to a bracket formed on an automobile body, A rivet-shaped fastener made of synthetic resin may be used. Such a fastener comprises a grommet having a tubular portion whose one end can expand outwardly, and a pin that is inserted into the center hole of the tubular portion to expand one end of the tubular portion. Some are known (see Japanese Utility Model Application Laid-Open No. 64-45020).

Conventionally, it has been emphasized that the rivet-shaped fastener can be attached with a small force and that a high holding force can be obtained, and its detachability has not been considered so far. .

[0004]

In recent years, however, there has been an increasing trend to pay attention to the recyclability of parts and materials, and it is desired to improve not only the workability of mounting but also the workability of dismantling. ing.

[0005] The present invention has been made based on such a viewpoint, and its main purpose is to improve not only the mounting workability and the holding force but also the dismantling workability. It is to provide an improved fastener.

[0006]

In order to achieve the above object, in the present invention, a cylindrical portion (6) whose both ends in the axial direction are opened by a through hole (female screw hole 4 in the embodiment), A grommet (2) having an axial slit (7) formed at one end of the tubular portion and a flange (5) formed at the other end of the tubular portion, and one end of the tubular portion is expanded. A fastener (1) consisting of a pin (3) inserted into the through-hole is inserted into the through-hole by forming an enlarged portion (9) larger than the inner diameter of the through-hole at one end of the pin. By moving the pin in the axial direction so as to be pulled out from the flange side, one end of the cylindrical portion can be pushed outward by the enlarged diameter portion.
According to this, by tapping the other end of the pin protruding from the flange side, the enlarged diameter portion can be brought out of the through hole, so that the fastening state can be easily released.

In particular, if at least a part of the grommet and the pin are screwed to each other, the tightened state and the loosened state can be relatively easily selected by relatively twisting the grommet and the pin. In addition, if the pin is formed by a two-color molding method in which a pre-molded pin is inserted, the manufacturing process can be simplified since a punching core for forming a female screw in the grommet is not required.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a fastener constructed according to the present invention. The fastener 1 is used, for example, when attaching an assembly of a washer liquid tank and an air duct to a bracket formed on the body of an automobile, and has a bonding force between the base material B and the member M to be attached. And a pin 3 for expanding one end of the grommet 2 so that the grommet 2 cannot be removed from the base material B.

The grommet 2 has a female threaded hole 4 penetrating in the axial direction, and has a cylindrical portion 6 having a circular or rectangular flange 5 formed at one end thereof. An axial slit 7 is formed in the cylindrical portion 6 from the other end of the cylindrical portion 6 to the base of the flange 5.

The pin 3 has a male screw shaft 10 having a hexagonal head 8 formed at one end and an enlarged diameter portion 9 having a diameter larger than the inner diameter of the female screw hole 4 at the other end. are doing.

In this fastener 1, a grommet 2 is formed by injecting a material having a relatively low melting point around the pin 3 in a state where a pin 3 previously injection-molded with a material having a relatively high melting point is inserted. It is formed by a so-called two-color molding method. As described above, if the fastener 1 composed of the grommet 2 and the pin 3 is formed by the two-color molding method, the external thread can be molded in a split mold, so that the pin 3 can be formed relatively easily. Since the grommet 2 is formed using the core as a core, the formation of the female screw hole 4 becomes extremely easy. Further, since it is not necessary to remove the core after molding, the number of steps can be significantly reduced. Also, since the melting points are different from each other, the two that are not fused can be easily separated by twisting each other after the die is cut, and since they are formed as one part, they can be supplied to the assembly line as they are. Also, parts management can be simplified.

Next, how to use the fastener 1 will be described.

First, the fastener 1 in a state where the grommet 2 and the pin 3 are sub-assembled is inserted into both holes where the base material B and the member to be mounted M are overlapped and aligned with each other ( (See FIG. 1).

Next, the hexagonal head 8 is twisted with a wrench of a general-purpose tool, and the pin 3 with the male screw shaft 10 screwed into the female screw hole 4 of the grommet 2 is pulled upward. Then, the enlarged diameter portion 9 of the pin 3 enters the cylindrical portion 6 of the grommet 2, so that the slit 7 is pushed and expanded, and the free end of the cylindrical portion 6 is expanded (see FIG. 2). Thereby, mutual fixation of the base material B and the to-be-attached member M via the fastener 1 is achieved.

At the time of normal maintenance, if the hexagonal head 8 is twisted with a wrench and the pin 3 is put in and out of the grommet 2, the base material B and the material to be mounted M can be freely connected and separated. .

At the time of disassembly, if the enlarged diameter portion 9 of the pin 3 is pushed out from the female screw hole 4 of the grommet 2 by hitting the hexagonal head 8 with an appropriate hitting tool such as a hammer, the cylindrical portion 6 is elastically formed of the material itself.
Is restored to the original shape, that is, the slit 7 is closed (the state of FIG. 1), so that the fastener 1 can be easily removed. At this time, the screw portion is broken, but there is no need to consider the reuse of the fastener 1 after disassembly, so there is no problem.

The hexagonal head 8 may be provided with an engaging groove 11 for engaging with a Phillips screwdriver, or the male screw shaft 10 may be provided with a hexagonal hole (not shown) for engaging with an Allen wrench. good.

FIGS. 3 and 4 show a second embodiment of the present invention. In this case, the grommet 2 and the pin 3 are not screwed, but are connected by a simple frictional force between the through hole 14 and the shaft portion 15. In this case, the hexagonal head 8 is replaced with a flange-shaped one. The enlarged diameter head 12 may be formed at one end of the pin 3, and the pin 3 may be pulled up by a lever 13 having a bifurcated engagement with the enlarged diameter head 12. Other functions and the procedure for releasing the fastening are the same as described above.

Since the fastener 1 of the present invention breaks by applying a blow to the tip of the pin 3 protruding from the grommet 2, if an unintended external force is applied to the tip of the pin 3, the member to be attached may be damaged. M does not necessarily fall off from the base material B. In order to cope with such inconvenience, as shown in FIG. 5, a locking piece 21 having a thickness that can be inserted into the gap G between the flange 5 and the hexagonal head 8 in the fastened state is prepared, and this is provided. It is good to be inserted in the gap G. This locking piece 21
Can also be used as a gauge for an appropriate amount of lifting of the pin 3. Needless to say, the locking piece 21 is removed in advance during the removal. Also, as shown in FIG.
Is formed integrally with the wire harness clip 22, for example, the gap G between the flange 5 and the hexagonal head 8 is formed.
Can be used as a holding portion of the wire harness clip 22.

As means for preventing the grommet 2 from dropping off, as shown in FIG. 7, an annular wall having its end surface on the flange 5 of the grommet 2 on a plane substantially equal to the top surface of the pin 3 projecting in the mounted state. 8, an annular wall 24 surrounding the flange 5 is provided on the mounting portion of the grommet 2 of the member M to be mounted, as shown in FIG. Operation may be prevented. In this case, the torsion of the shaft 10 is
The inner diameter of the annular wall 23 (24) may be set so that a box wrench can be inserted, or a Phillips screwdriver or an Allen wrench may be used. Also, when leaving,
What is necessary is just to hit the pin 3 via a punch etc.

[0022]

As described above, according to the present invention, the function and the holding force as the fastener do not need to be reduced as compared with the conventional one.
In addition, since the fastening state can be easily released simply by hitting the end of the pin protruding from the flange side of the grommet, a great effect can be achieved in improving the disassembly without impairing the mounting property and the holding force. .

In particular, if at least a part of the grommet and the pin are screwed to each other, the tightened state and the loosened state can be relatively easily selected by relatively twisting the grommet and the pin. Therefore, usability can be improved. In addition, if the fastener is formed by a two-color molding method in which a pre-molded pin is inserted, a punching core for forming a female screw is not required, so that the manufacturing process can be simplified.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state in which a fastener in a sub-assembly state has passed through holes of a base material and a member to be mounted.

FIG. 2 is a longitudinal sectional view showing a final state of fastening of the fastener.

FIG. 3 is a longitudinal sectional view similar to FIG. 1 showing another embodiment.

FIG. 4 is a longitudinal sectional view similar to FIG. 2, showing another embodiment.

FIG. 5 is a vertical cross-sectional view showing an example of a stopper preventing means of the fastener.

FIG. 6 is a perspective view showing a form in which a means for preventing a fastener from falling off is provided on a wire harness clip.

FIG. 7 is a longitudinal sectional view showing another embodiment of the stopper preventing means of the fastener;

FIG. 8 is a longitudinal sectional view showing still another embodiment of a stopper preventing member from falling off.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fastener 2 Grommet 3 Pin 4 Female screw hole 5 Flange 6 Cylindrical part 7 Cutting 8 Hexagonal head 9 Large diameter part 10 Male screw shaft 11 Engagement groove 12 Large diameter head 13 Lever

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tomoaki Sato 184-1, Maioka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Nifco Corporation (72) Inventor Tomoo Eguchi 184-1, Maioka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Nifco F-term (reference) 3J025 AA02 AA07 BA02 BA32 CA01 DA01 3J036 AA05 FA06

Claims (3)

[Claims] 1. A cylindrical portion having both ends opened in the axial direction by a through hole, an axial cut formed from one end of the cylindrical portion, and a flange formed at the other end of the cylindrical portion. A fastener comprising a grommet and a pin inserted into the through hole so as to expand one end of the cylindrical portion, wherein an enlarged portion having a diameter larger than the inner diameter of the through hole is provided at one end of the pin. One end side of the cylindrical portion is pushed outward by the enlarged diameter portion by axially moving the formed pin inserted into the through hole in a direction to be pulled out from the flange side. Fastener. 2. The fastener according to claim 1, wherein at least a part of the grommet and the pin are screwed to each other. 3. The fastener according to claim 1, wherein the fastener is formed by a two-color molding method in which the preformed pin is inserted.