JPH0420088B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a screw grommet used for connecting panels, etc. More specifically, even when applied to a circular mounting hole, it does not work as a bolt. Concerning screw grommets that do not rotate together.

[Conventional technology]

As a connecting member for connecting panels,
A plastic screw grommet having a screw insertion hole bored in the flange body, and two legs protruding from the outer periphery of the lower end of the insertion hole, facing each other at a predetermined distance. is known (Utility Model Application Publication No. 49-55907). When using this screw grommet, insert the above-mentioned legs into the square mounting holes of the first panel while bending them inward. By elastically returning both legs to their original states upon release, the first panel is supported at the proximal ends of these legs and brought into contact with the lower surface of the flange, and in this state, the shaft of the screw is moved to the second By sequentially passing the screw through the mounting hole of the panel and the insertion hole of the flange body and inserting it between the legs, the screw formed on the outer periphery of the screw shaft can be inserted into the inner surface of the legs. The screw shaft is advanced between these two legs while the corresponding threaded portion is screwed, and the first panel is pressed by the two legs whose lower portions are spread outward, thereby fixing it to the connector. , which connects the two panels mentioned above to each other, but since this grommet is a self-tapping type, if the mounting hole is circular, it will rotate with the screw, so it cannot be applied to circular mounting holes. The drawback is that it cannot be done.

On the other hand, as a screw grommet that can be applied to a circular mounting hole, a structure as shown in FIG. 10 is known (Japanese Patent Laid-Open No. 192908/1983). This screw grommet has a bolt insertion hole b formed in the flange body a, and a bolt insertion hole b formed in the flange body a.
A pair of legs c, c facing each other at a predetermined distance are integrally provided on the outer peripheral edge of the lower end, and threads d are screwed into the inner peripheral wall at the inner edge of the lower end of these legs c, c. The cylindrical nut bodies e are integrally connected through thin wall portions f, f.

To use this screw grommet, insert the nut body e and both leg bodies c and c into the circular mounting hole h of the first panel g, as shown in FIG. After bringing the lower surface into contact with the first panel g and temporarily fixing the grommet to the first panel g by the engaging protrusions i, i of the legs c, c, in this state, the shaft of the screw j is moved to the first panel g. 2. Sequentially pass through the mounting hole l of panel k and the insertion hole b of flange body a, screw onto nut body e, and rotate screw j. Then, after the screw j advances and its head abuts on the second panel k, the nut part e is pulled up in the direction of the legs c, c, the thin parts f, f break, and the nut part e moves between the legs c and c while pushing the lower portions of the legs c and c outward, and as a result, the legs spread outward press the first panel g and push it into the screw groove. The two panels g and k are connected to each other. In this case, when the legs c, c are pushed apart, the outer surfaces of the legs c, c press the peripheral wall of the mounting hole h of the first panel g, but this pressing force is caused by the nut body e pushing the legs c, The pressure becomes stronger as the grommet progresses through C, so this pressing force prevents the grommet from rotating together with the screw.

[Problem to be solved by the invention]

However, the screw grommet described in Japanese Patent Application Laid-open No. 61-192908 mentioned above has both leg bodies c and c.
Since it has a structure in which a nut body e is connected to the tip of the
As the axial length of the grommet becomes longer, a relatively long screw j must be used, and after connecting both panels g and k, the screw j
Since the shaft portion of the first panel g protrudes for a long time on the back side of the first panel g, there is a drawback that it cannot be used unless there is sufficient space on the back side of the first panel g.
Further, since the nut body e is pulled up by the screw j and the leg bodies c and c are spread apart, there is a problem that the working time for rotating the screw j is long and the working efficiency is poor.

The present invention has been made in view of the above circumstances, and has a short shaft length, so it is possible to use a screw with a relatively short shaft, and therefore, when there is no large space on the back side of the panel to be mounted (first panel). In addition to being able to reduce the work time required to rotate the screw and improve work efficiency, it also allows the screw to rotate with the screw even if the mounting hole of the panel to which it is mounted is circular. The purpose is to provide screw grommets that are free of screw grommets.

[Means to solve the problem]

That is, in order to achieve the above object, the present invention provides a flange body with a screw insertion hole, and a plurality of legs protruding from the outer peripheral edge of the lower end of the insertion hole at a predetermined distance from each other. Insert the legs into the attachment holes of the object to be attached, bring the object into contact with the lower surface of the flange body, enter the shaft of the screw between the plurality of legs through the screw insertion holes, and insert the screw. By rotating the screw, the threaded portion formed on the outer periphery of the shaft portion of the screw threads a threaded portion corresponding to the threaded portion on the inner surface of each of the legs, and the screw shaft portion is advanced between these legs. In a coupling device that fixes an object to be attached by pressing the object to be attached with legs whose lower portions are spread outward, an inverted U-shaped slit hole is bored in each of the legs. A claw part is formed inside the slit hole, the upper end of which is a free end, into which the screw is screwed, and the middle part of the outer surface length direction of both claw parts is bulged outwardly to form a claw part. The upper part of the outer surface of each of the upper and lower outer surfaces thereof is formed into a tapered surface that gradually protrudes outward as it goes downward.

Further, in this case, as a preferred embodiment of the present invention, there is provided a screw grommet in which a slip resistance member made of a soft material is disposed on the lower surface of the flange body.

[Effect]

The screw grommet of the present invention has a claw portion in which the upper end of the leg body is a free end, the middle part of the outer surface bulges outward, and the upper part of the outer surface has a tapered surface that gradually projects outward as it goes downward. By providing this, when the screw is screwed in between the legs, the upper part of the claw expands outward at the initial stage of screwing in, and the tapered surface directs the peripheral wall of the mounting hole of the object to be mounted toward the flange. This pressing force presses the lower surface of the flange against the object to be mounted, and the surrounding wall of the mounting hole is strongly clamped by the tapered surface and the lower surface of the flange. Even if the hole is circular, it will not rotate with the screw. In addition, as the screwing progresses and the lower part of the entire leg expands outward, the tapered surface presses the peripheral wall of the mounting hole more strongly, and the lower surface of the flange body is pressed more strongly against the object to be attached, which prevents co-rotation. This will further increase the power of prevention.

In this case, by arranging a slip resistance member made of a soft material on the lower surface of the flange body, the slip resistance generated by sandwiching the peripheral wall of the mounting hole between the tapered surface and the lower surface of the flange body will be increased, making it more reliable. Co-rotation can be prevented.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples.

〔Example〕

1 to 6 show one embodiment of the present invention, in which the screw grommet is integrally molded from flexible plastic.

In the figure, 1 is a disc-shaped flange body having a circular screw insertion hole 2 in the center. This flange body 1 has a circular ring-shaped protrusion 3 at the center of the lower surface,
As a result, a circular ring-shaped soft material arrangement groove 4 is formed outside the protrusion 3, and a circular ring-shaped slip resistance member 5 made of a soft material is disposed within this groove 4. There is. Note that the lower end of the circular slip resistance member 5 projects further downward than the lower end of the protrusion 3. Further, on the outer peripheral edge of the lower end of the insertion hole 2 of the flange body 1, there are two legs 6, 6 having a substantially semicircular cross section that face each other with a predetermined distance apart, with the distal end side being more mutually disposed than the proximal end side. They are protruded from each other and spaced apart from each other.

Here, an inverted U-shaped slit hole 7, 7 is bored in each of the leg bodies 6, 6 from the lower part to the upper end, so that the upper end becomes a free end inside the slit hole 7, 7. Square claw portions 8, 8 are formed to face each other, and these claw portions 8,
The longitudinally intermediate portion of the outer surface of 8 is bulged outward in a chevron shape, thereby forming an engaging protrusion 9 in the intermediate portion.
9 are respectively formed, and upper tapered surfaces 10, 10 are formed above the engaging protrusions 9, 9 on the outer surface of the claw portions 8, 8 and gradually protrude outward toward the lower end.
Below, there are lower tapered surfaces 11, 11 that gradually protrude outward toward the upper end. In addition,
Round grooves 12, 12 for screw shaft insertion are formed in the inner surfaces of the claws 8, 8 along the axial direction so as to face each other. In addition, the bases of the legs 6, 6 (portions where the claws 8, 8 are not formed) 6
The intermediate portions in the longitudinal direction of a, 6a are also slightly bulged outward in a mountain shape, thereby forming the base portions 6a, 6a.
On both sides of the engaging protrusions 9, 9 of the claws 8, 8, both engaging protrusions 13, 13 and 13, 13 are formed.

Furthermore, when inserting both legs 6, 6 of the grommet of this embodiment into the circular mounting hole of the object to be mounted, the claws 8, 8 and the bases 6a, 6 are inserted as shown in FIG. 8, which will be described later.
A is the diameter of the circular mounting hole, and B is the distance between the outermost edges of the claws 8 and 8 when the grommet is in its normal state and when inserted.
Assuming that B' is the distance between the outermost edges of both base parts 6a and 6a when the grommet is in its normal state and when it is inserted, C and C' (see Figures 2 and 8), in this embodiment, each of the above dimensions is B> C, B>A, B′≧A, B′=
It is set to be C′. In this case, the distance B between the outermost edges of the claws 8, 8 in the normal state is considerably larger than the diameter A of the attachment hole, and is formed to have the maximum width that can pass through the attachment hole.

When using the screw grommet described above, first, as shown in FIG.
5, the legs 6, 6 are inserted, and grommets are attached to the first panel 14. In this case, when the legs 6, 6 are inserted into the mounting hole 15, both the claws 8, 8 will move into the mounting hole 1 as the legs 6, 6 move forward, as shown in FIG.
5 bends inward due to the pressing force of the surrounding wall, then both bases 6
a, 6a bend inward together with both claws 8 due to the above-mentioned pressing force, and when the pressing force is released after insertion, both leg bodies 6, 6 elastically return to their original state, and as shown in FIG. As shown in FIG.
The slip resistance member 5 of the flange body 1 comes into contact with the first panel 14 and is temporarily fixed, but in this state, the claws 8, 8
The upper end of the upper tapered surfaces 10, 10 is the mounting hole 15.
The grommet contacts the peripheral wall portion and is securely locked to the first panel 14.

Next, the second panel 16 is arranged with its mounting hole 17 aligned with the screw insertion hole 2 of the flange body 1, and as shown in FIG. 2 in turn, enter between the round grooves 12, 12 of both claw parts 8, 8, and rotate the screw 18. As a result,
A threaded portion 18c formed on the outer periphery of the screw shaft portion 18a spirally engraves the inner surface of the round grooves 12, 12, and a threaded portion corresponding to the threaded portion 18c is formed in the round groove 1.
2, 12 are threaded on the inner surfaces thereof, and as the screw shaft portion 18a advances into the space between the round grooves 12, 12, the lower portions of both leg bodies 6, 6 open outward, and these leg portions press the first panel 14. As shown in FIG. 9, the first panel 14 is fixed to the grommet, whereby the first and second panels 14,
16 are connected to each other.

In this case, in the above grommet, a slip resistance member 5 made of a soft material is provided on the lower surface of the flange body 1, and the upper ends of the leg bodies 6, 6 are made free ends, and the upper ends of the outer surfaces have tapered surfaces 10, 10. By forming the claw parts 8, 8, the claw parts 8, 8 are formed as shown in FIG.
8 opens outward and presses the peripheral wall of the mounting hole 15 (see arrows X, 10 bites into the first panel 14, and therefore, the sliding resistance of the slip resistance member 5 and the biting of the upper tapered surfaces 10, 10 into the first panel 14 prevent the grommet from rotating together with the screw. Also, as the screw advances, the legs 6, 6 as a whole expand outward as shown in FIG. 9 (see arrows Y and Y).
As a result, due to the lever principle, the upper tapered surface 10,
10 strongly presses the first panel 14 (arrows Z, Z
As a result, the slip resistance member 5 is pressed more strongly against the first panel 14, increasing the slip resistance, and the first panel 14 bites into the upper tapered surfaces 10, 10 more, so that the co-rotation is stronger. Prevented. Furthermore, the grommet is firmly fixed to the first panel 14 by the biting.

That is, in this example, by disposing a slip resistance member made of a soft material on the lower surface of the flange body, the slip resistance increased and co-rotation could be more effectively prevented. Of course, the present invention also includes those in which no slip resistance member is provided on the lower surface of the body. The type of soft material constituting the slip resistance member is not limited, but a material with high slip resistance such as a nylon elastomer is preferably used. Further, the means for disposing the slip resistance member is not limited, but there are methods such as disposing a ring-shaped slip resistance member made of a soft material at the lower part of the flange body, or providing a soft material at the lower part of the flange body by two-color molding. is preferably adopted.

In addition, in the above example, two legs were formed, but
Three or more may be formed. Moreover, although the flange body is formed into a disk shape, it may be formed into a square plate shape, and other configurations may be modified in various ways without departing from the gist of the present invention.

〔Effect of the invention〕

As explained above, by having the screw grommet of the present invention configured as described above, it is reliably prevented from rotating together with the screw.
It can be applied not only to rectangular mounting holes but also to circular mounting holes. In this case, the grommet of the present invention has a short axis and a relatively short screw can be used, so it can be used even when there is not a large space behind the panel to which it is attached, and the working time for screw rotation can be shortened. , which can improve work efficiency.

[Brief explanation of drawings]

1 to 6 each show an embodiment of the present invention. FIG. 1 is a front view, FIG. 2 is a side view, FIG. 3 is a plan view, FIG. 4 is a bottom view, and FIG. The figure is a cross-sectional view taken along the line of FIG. 3, FIG. 6 is an end view taken along the line of FIG. 1, and FIG. A sectional view showing the initial state of screwing in, FIG. 8 is an explanatory view showing the state in which the leg of the grommet is inserted into the mounting hole, and FIG. 9 is a sectional view showing the state in which the panels are connected to each other using the same grommet. , 10th
The figure is a cross-sectional view of a conventional screw grommet.
FIG. 11 is a sectional view showing a state in which the panels are connected to each other using the same grommet. 1...Flange body, 2...Screw insertion hole,
5... Slip resistance member, 6... Leg body, 7... Slit hole, 8... Claw portion, 10... Upper tapered surface, 1
4...First panel, 15...Mounting hole, 16...Second panel, 17...Mounting hole, 18...Screw, 18a...Screw shaft portion, 18c...Threaded portion.

Claims (1)

[Scope of Claims] 1. A screw insertion hole is formed in the flange body, and a plurality of legs are provided protruding from the outer peripheral edge of the lower end of the insertion hole at a predetermined distance from each other, and these legs are connected to the object to be attached. The screw is inserted into the mounting hole and the object to be mounted is brought into contact with the lower surface of the flange body, the shaft of the screw is inserted between the plurality of leg bodies through the screw insertion hole, and the screw is rotated. The threaded portion formed on the outer periphery of the shaft portion is threaded into the inner surface of each of the legs, and the screw shaft portion is advanced between these legs, so that the lower part of each leg is moved outwardly. In a coupling device that fixes the object to be attached by pressing the object with the spread legs, an inverted U is attached to each of the legs.
A letter-shaped slit hole is bored inside the slit hole, the upper end is a free end, and a claw portion into which a screw is screwed is formed. A screw grommet characterized in that the upper part of the outer surface of the claw part is formed into a tapered surface that gradually projects outward as it goes downward. 2. The screw grommet according to claim 1, wherein a slip resistance member made of a soft material is disposed on the lower surface of the flange body.