JPS6218732Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a driven fastener.

There are various types of synthetic resin fasteners that are used to connect objects by driving, and there is one such as shown in FIG. 1, for example. This driving fastener 1 has a leg part 6 inserted into the mounting holes 4 and 5 of the laminated mounting plates 2 and 3, and a flange part 7 for a stopper that extends from above the leg part 6 to the periphery. It is equipped with a hollow main body 8 and a pin 10 that is press-fitted into the hollow part 9 of the main body 8 to spread the legs 6 in the radial direction or to prevent the legs 6 from bending inward. Main body 8 and pin 1
0 is connected via a thin film 11 that can be easily cut during implantation, and the entirety is integrally molded from a synthetic resin material. As shown in the figure, this thin film 11 connects the lower edge of the pin 10 and the upper edge of the hollow portion 9 of the main body 8, and the bottom surface 12 of the pin 10 is located approximately at the same position as the top surface of the flange portion 7. However, in such a conventional driving fastener 1, the pin 10 may fall off from the main body 8 during driving. That is, if the pin 10 is driven in a direction away from the axial direction of the pin 10 or the main body 8 (for example, in the direction of arrow A in FIG. 1), the entire thin film 11 will be cut. First, as shown in FIG. 3, a portion 11a of the thin film is cut, and a portion 11b of the thin film is not cut, and the bottom surface 12 of the pin 10, which is located at approximately the same height as and close to the flange portion 7, is not cut. This is because, as it is bent, it ends up riding on the flange portion 7 (FIGS. 2 and 3). Therefore, a large amount of loss is likely to occur during the driving process, and in some cases, the mounting plates 2 and 3 may be damaged.

Therefore, although not shown, the lower edge of the pin 10 and the main body 8
The bottom surface 12 of the pin 10 is extended into the hollow part 9 while being connected to the upper edge of the hollow part 9 by the thin film 11, and the lower part of the pin 10 that has entered the hollow part 9 is connected to the inner surface of the hollow part 9. By making it a guide for
It may be possible to prevent the pin 10 from bending during driving so that the pin 10 can be driven straight, but this would prevent the hollow part of the main body 8 from being cut if the thin film 11 is difficult to cut during driving. The upper edge of the pin 9 may be pulled inward and buckled or deformed at the same time as the pin 10 is driven in. If this buckling or deformation occurs, it will not only interfere with the driving of the pin 10, but also
Since the buckled/deformed portion attempts to restore itself in the opposite direction to the driving direction of the pin 10, the resistance becomes large and the driving force of the pin 10 becomes large, and furthermore, the surrounding area is damaged due to the buckling/deformation. The flange portion 7 was also deformed and the appearance was unfavorable.

The present invention was made with attention to these points, and consists of a body that is entirely hollow and has a leg that can be inserted into the mounting hole and a flange for a stopper that protrudes from above the leg. In a driving fastener that is integrally molded from synthetic resin and has a pin that can be press-fitted into the part connected by a thin film, the pin is inserted into the hollow part of the main body in advance and has a long driving head that protrudes upward from the main body. and a short guide portion that is recessed, and the outer diameter of the guide portion is smaller than the outer diameter of the head to form a gap between the outer circumferential surface of the guide portion and the inner circumferential surface of the main body. The purpose of this invention is to solve the above-mentioned conventional problems by forming the thin film between the inner circumferential surface of the main body located below the upper edge of the hollow part of the main body and the corresponding guide part. .

The details of this invention will be explained below based on FIGS. 4 to 7. In addition, in FIGS. 4 to 7, the same parts are indicated by the same reference numerals, and among the driven fasteners according to the present invention, the same parts as the conventional driven fasteners (FIGS. 1 to 3) This section is limited to a general explanation and mainly describes the improved parts in detail.

First, the driving fastener 13 according to the present invention is roughly divided into a hollow main body 14 and a pin 15. The hollow body 14 has a leg portion 28 and a flange portion 16, while the pin 15 has an elongated driving head 17 projecting upwardly from the body 14 and is previously inserted into the hollow portion 18 of the body 14. A short guide portion 19a is provided for positioning. Hollow body 14
and the pin 15 are connected by a thin film 20a, and the entire driving fastener 13 is integrally molded from a synthetic resin material. That is, the lower part of the pin 15 is positioned in the hollow part 18 of the main body from the beginning, and this lower part is formed as a guide part 19a for the inner surface 21 of the hollow part 18.

In the specific example shown in FIG. 4, the lower outer circumferential surface of the guide part 19a and the inner circumferential surface in the middle of the hollow part 18 of the main body 14 are connected by a thin film 20ba, and furthermore, in the specific example shown in FIG. Outer surface and main body 1
The inner peripheral surface of the hollow portion 18 of No. 4 is connected to the intermediate inner circumferential surface of the hollow portion 18 by a thin film 20b. Therefore, even if the thin films 20a and 20b are difficult to cut when driving the pin 15, the main body 14 is prevented from buckling or deforming. Note that the thin film needs to be formed at least between the inner circumferential surface of the main body located below the upper edge of the hollow part of the main body and a corresponding position. And pin 1
5 and the main body 14 are integrally molded from a synthetic resin material so as to be connected through thin films 20a and 20b. Hollow part 1 of main body 14
There is a slight gap 2 between the outer peripheral surfaces of the guide portions 19a and 19b that are inserted into the inner peripheral surface of the hollow portion 18.
2 is formed so that the pin 15 can be driven easily and reliably. In addition, the guide parts 19a, 19b
The outer diameter size of the upper head 17 is larger than the size of the guide part, but it is made to be the same as or slightly smaller than the inner diameter size of the hollow part 18.

The inner diameter size of the hollow part 18, especially the leg part 2
The inner diameter size around 8 is the guide part 19a, 19b.
It is necessary to make the outer diameter size smaller than the outer diameter of the leg 28. For this reason, either an interfering bulge 23 is provided on the inner surface 21 of the hollow part near the leg 28, or the leg 28 is made so that the diameter of the hollow part near the bulge 23 is reduced. may be formed in a "tapered" state. In the illustrated example, the leg portion 28 is a cylinder divided into four parts, but the number of divisions is arbitrary, and the leg part 28 may be made into a cylindrical shape instead of being divided into four parts.

Reference numeral 24 indicates a thin wall portion formed on the outer periphery of the flange portion 16, and 25 indicates a protrusion formed on the outer periphery of the leg portion 28.

Next, the action will be explained. With the legs 28 of the main body 14 inserted into the mounting holes 4 and 5 of the mounting plates 2 and 3, from the axial direction [arrow B in Fig. 4] with respect to the driving head 17 of the pin 15. Add driving force. The membranes 20a, 20b are cut in response to the driving, and the pin 15 penetrates into the leg 28 of the main body. In this case, the thin films 20a and 20b are the main body 14 and the hollow part 18.
Since it is connected to the inner peripheral surface in the middle, there is no risk of buckling or deforming the main body 14 during cutting.
The driving force for the pin can also be small. Also, pin 15
Since the lower part of the guide portions 19a and 19b are placed in the hollow portion 18 of the leg portion 28 in advance,
These guide portions 19a, 19b exhibit a guiding function for the inner surface of the hollow portion 18, and the guide portions 19a,
The pin 15 consisting of the head 19b and the head 17 is connected to the gap 22.
Coupled with the presence of , it can be press-fitted into the hollow portion 18 smoothly. Then, the guide portion 19a does not expand or contract the diameter of the leg portion 28 in the radial direction, so that the engagement state with the mounting holes 26 and 27 is securely fixed. If the head 17 of the pin 15 is driven in a direction away from the axis (arrow C in FIG. 4), even if the entire pin 15 becomes slightly inclined 15', Since the guide portions 19a and 19b below the pin 15 are inserted into the hollow portion 18, the outer peripheral surfaces of the guide portions 19a and 19b interfere with the inner surface 21 of the hollow portion 18 to prevent the pin 15 from tilting excessively. Since the pin 15 functions as a guide for the inner surface 21, the pin 15 is press-fitted into the main body 14 without falling off from the main body 14.

As explained above, the structure of this idea is
An integral body made of synthetic resin with a thin film connecting a completely hollow main body with legs that can be inserted into the mounting holes and a flange for a stopper that protrudes from above the legs, and a pin that can be press-fit into the hollow part of the main body. In a molded driving fastener, the pin is formed of a long driving head projecting upward from the main body, and a short guide part that is inserted in advance into the hollow part of the main body, and this guide part The outer diameter of the head is smaller than the outer diameter of the head to form a gap between the outer circumferential surface of the guide part and the inner circumferential surface of the main body, and the thin film is located in the hollow part of the main body below the upper edge. Because it is formed between the inner peripheral surface of the main body and the corresponding guide part, the thin film When cutting, the main body does not buckle or deform, and a good appearance can be maintained during installation.In addition, the driving force is small, and the guide part is always hollow when driving. Since the pin acts as a guide against the inner surface of the body, the pin will enter the hollow part of the main body in the intended state and will not fall out of the main body, and the gap between the guide part and the inner peripheral surface of the main body will prevent the pin from being driven in. It is easy and reliable, and as a result, not only is there no work loss involved in the conventional process, but the risk of damaging the mounting plate is also eliminated, making the molding process easier and cheaper. Combined with the fact that it can be mass-produced, it is highly profitable.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional driving fasteners, with Figure 1 being a partially cutaway front view and Figure 2
3 is an enlarged sectional view of the middle part of FIG. 2, FIGS. 4 and 5 are sectional views showing specific examples of the driving fastener according to the present invention, and FIG. This figure is a sectional view showing the driving state of the driving fastener shown in FIG. 4. In the figure, 13... driving fastener, 14... hollow body, 15... pin, 16... flange part of main body, 17... head of pin, 18... hollow part of main body, 19a, 19b... ...Pin guide part, 20
a, 20b... Thin film connecting the pin and the main body.

Claims (1)

[Scope of Claim for Utility Model Registration] A thin film comprising a wholly hollow main body having legs that can be inserted into mounting holes and a flange for a stopper that protrudes from above the legs, and a pin that can be press-fitted into the hollow part of the main body. In the driving fastener integrally molded with synthetic resin connected by and the outer diameter of the guide portion is smaller than the outer diameter of the head to form a gap between the outer circumferential surface of the guide portion and the inner circumferential surface of the main body, and the thin film is formed in the hollow portion of the main body. A driving fastener characterized by being formed between an inner circumferential surface of the main body located below the upper edge and a guide portion at a corresponding position.