JPH0225688B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for attaching a spacer, and more particularly to a method for effectively attaching a spacer to a hole in an object without the risk of cracking.

Conventionally, a spacer is attached to a hole in a product for the purpose of protecting the hole, and the product is fixed to another member via the spacer. As an example of a method for attaching this spacer, a method for attaching an eyelet clip to a hole in a plate material by caulking is described. As shown in FIG. Insert the eyelet clip 6 in the shape of , and then insert the guide pin 8 with cushion.
After setting the molds between the lower mold 10 and the upper mold 12 having the same shape as shown in FIG. 1, the molds are clamped using an ordinary press machine as shown in FIG. will end.

However, natural cracks are inevitably formed in the eyelet clip 6 when it is crimped. Therefore, when such caulking products are used with vibration, the cracks may become enlarged during use, and rust may occur in the cracks if the product is in a corrosive environment where rust is likely to occur. There is a possibility that Moreover, when the eyelet clip 6 is a plated product, corrosion progresses from the cracks, and depending on the place of use, a decrease in strength may become a problem. Furthermore, in this attachment method, the cylindrical portion of the eyelet clip 6 must be pushed and expanded so that a crack occurs at its tip, which not only requires a large caulking load but also causes the middle portion of the cylindrical portion to bulge. A mechanism that would not blind was required, making the crimping mechanism complicated and the equipment cost unavoidably high. In addition, since the shape of the crimped part of the product after crimping is not uniform, the shape of the product is not consistent, resulting in disadvantages such as poor appearance of the product.

Further, when attaching the spacer 24 to the hole 22 of the plastic plate 20 as shown in FIG. 4, the situation is exactly the same as in the case described above, and in this case, the crimping is not performed. If it is too strong, there is a risk that the plastic plate 20 itself will be damaged.

The present invention has been devised in view of the above circumstances, and is designed to simplify the structure, use inexpensive equipment, and allow the spacer to be attached to an object to be attached without the risk of cracking or rusting. The purpose of this invention is to provide a method for attaching a spacer.

In order to achieve this object, the present invention involves inserting a predetermined spacer having a flange part and a cylindrical part into a hole provided in a product made of a relatively soft material such as resin, When fixing the spacer in the hole, the inner circumferential surface of the product hole is tapered or shaped on the flange side of the spacer to be inserted so as not to interfere with the curved base of the spacer. While cutting with a curved surface, the cylindrical portion of the spacer inserted into the hole is pushed outward in the radial direction from the base to the tip by the pressing action of a punch having a tapered surface. By simultaneously deforming the side portion of the hole and making the cylindrical portion of the spacer into a reversely tapered cylindrical portion, the flange portion of the spacer and the reversely tapered cylindrical portion are formed on the side of the hole. The purpose of the present invention is to adopt a spacer mounting method characterized in that the spacer parts are sandwiched.

In this way, the cylindrical part of the spacer inserted into the product hole is pushed outward to form a reversely tapered cylindrical part, and the periphery of the product hole is sandwiched between it and the flange part of the spacer. Therefore, since the cylindrical part is fixed, no cracks occur in the cylindrical part as in the conventional case, the cracks do not expand, and no rust or corrosion occurs due to the cracks. Since the processing is only done by expanding, the number of processing steps is reduced, the processing is easy, the equipment is simple, and the equipment cost can be reduced, which is an excellent effect. Furthermore, there is no longer any need to consider the possibility of damage to the product itself.

Moreover, according to the method of the present invention, the inner circumferential surface of the hole is
Since the tapered or curved surface is cut out, the sides of the hole do not interfere with the base of the cylindrical portion of the spacer, which is expanded by the pressing action of the punch. This exhibits a feature that makes it easy to deform the side portion and, furthermore, to make the cylindrical portion of the spacer into a reverse tapered shape.

Hereinafter, an example of the spacer attachment method according to the present invention will be explained in detail with reference to the drawings.

First, as shown in FIG.
The product 32, which is the attached object to which it is fixed, is made of a relatively soft material such as resin or wood.
Further, the hole portion 34 into which the spacer 30 is inserted is constituted by a through hole consisting of a large diameter portion 36, a truncated conical portion tapered surface cut portion 38, and a cylindrical portion 40. The spacer 30 is a pressed product of a metal plate, and consists of a flange portion 42 and a cylindrical portion 44. The thickness t of the flange portion 42 is such that it can be accommodated in the cavity formed by the large diameter portion 36 of the hole portion 34, and the height H of the spacer 30 is set to a thickness that allows the flange portion 42 to be accommodated in the cavity formed by the large diameter portion 36 of the hole portion 34. height H
It is said to be slightly larger in height.

And the product 3 previously formed in this way
The spacer 30 is inserted into the hole 34 of No. 2, and its flange portion 42 is accommodated in the large diameter portion 36 of the hole 34. Then, as shown in FIG. 6, they are set between a lower die 46 having a smooth upper surface and an upper die 50 having a punch 48 having a tapered convex surface in the shape of a truncated cone, and then a normal press machine is used. The mold is clamped as shown in FIG. It is pushed outward and deformed into a truncated cone shape. At this time, since the product 32 is made of a soft material, the cylindrical portion 4
The hole 34 circumscribing the cylindrical portion 4 is also deformed into a reverse tapered shape at the same time as the cylindrical portion 44 is deformed.
That is, the spacer 30 is distinctive in that it is not bent but is pushed out in a tapered shape from its base.

Thus, the spacer 30 has its flange portion 4
The side portion of the hole 34 is sandwiched between the cylindrical portion 44 having an inversely tapered shape and fixed to the hole 34 .

After the spacer 30 is fixed to the hole 34 in this way, the height H of the spacer 30, which is slightly higher than the height h of the hole 34, is
Since the cylindrical portion 44 has a truncated conical shape, the heights are almost the same.

In this way, if such a method is followed, the spacer 3
Since the 0 is not bent but merely expanded from its base to form a tapered shape, no cracks occur as in the conventional case. Therefore, there is no propagation of cracks, and therefore there is no risk of rust or corrosion occurring from the cracks. Moreover, since this process is simply a process of pushing and expanding the tapered shape, the press load is relatively small, and can usually be completed within about 350 kg. Therefore, the process is extremely easy, and the process is comparable to conventional ones. This has the great advantage of being shorter. Furthermore, it is not affected by the thickness of the product and can be suitably applied in any case, and is especially effective in battery supports in terms of corrosion resistance, durability, and ease of processing. be. Furthermore, problems such as the negative effects on products caused by excessive crimping, especially cracks around holes in resin products, etc., which occur in conventional crimping methods, have all been resolved.

In addition, in the above description, the height H of the spacer 30
is slightly higher than the height h of the hole 34 so that the height is the same after the spacer 30 is attached, so that it does not interfere with bolt tightening etc. through the spacer 30. However, the present invention is not limited to this in any way, and as long as there is no adverse effect, H>h or H<h is possible after installation, and in particular H<h. In the case h, the tip end 54 of the spacer 30 bites into the side surface of the hole 34 of the product 32, which makes it possible to achieve a unique effect in which the spacer 30 is more securely fixed.

In addition, since the truncated conical portion 38 as the tapered surface cut portion in the hole portion 34 of the product 32 does not interfere with the curved portion (base) of the spacer 30,
Even if it is not a truncated conical taper shape, there is no problem as long as it is a cutout that provides a curved surface similar to or that does not interfere with the curved portion, and furthermore, even if it is in the large diameter portion 36,
It's not necessarily what you need, spacer 3
If it is acceptable for the flange portion 42 of 0 to protrude from the surface of the product 32, the large diameter portion 36 may be omitted.

In addition, it goes without saying that various modifications and improvements can be made to the present invention based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

Fig. 1 is an explanatory cross-sectional view showing the set state immediately before the crimping process in the conventional spacer installation method, Fig. 2 is an explanatory cross-sectional view showing the state after the crimping process, and Fig. 3 is a perspective view of the crimped product. It is a diagram. FIG. 4 is an explanatory sectional view showing a set state before the crimping process in another conventional spacer attachment method, and FIG. 5 is an explanatory sectional view after the crimping process. FIG. 6 is an explanatory cross-sectional view showing a set state before attachment processing in the spacer attachment method according to the present invention, and FIG. 7 is an explanatory cross-sectional view showing a state after the attachment processing. 30: Spacer, 32: Product, 34: Hole, 4
2: Flange part, 44: Cylindrical part, 46: Lower mold, 5
0: upper mold, 52: base, 54: tip, t: flange thickness, H: spacer height, h: hole height.

Claims (1)

[Claims] 1. When inserting a specified spacer having a flange portion and a cylindrical portion into a hole provided in a product made of a relatively soft material such as resin, and fixing the spacer in the hole, the product The inner circumferential surface of the hole is cut out as a tapered surface or a curved surface at a portion on the flange side of the spacer to be inserted so as not to interfere with the curved base portion of the spacer, while the inner peripheral surface of the spacer to be inserted is The cylindrical part of the spacer is pushed outward in the radial direction from the base to the tip by the pressing action of a punch having a tapered surface, thereby simultaneously deforming the side part of the hole, A spacer installation characterized in that the cylindrical part of the spacer is formed into an inverted tapered cylindrical part so that the side part of the hole is sandwiched between the flange part of the spacer and the inverted tapered cylindrical part. Method.