JP2002035858A - Caulking hole forming method for caulking nut and caulking nut fitting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a caulking hole for fitting a caulking nut with excellent accuracy. SOLUTION: In a caulking hole forming method for a caulking nut for forming the caulking hole 2 for fitting the caulking nut on a plate 1, the caulking hole 2 includes the same shaped portion 3 connected to a face S1 of one side face of the plate 1 orthogonally to the face S1 and in the same shape, and a tapered portion 4 whose shape becomes gradually larger from the inner edge of the same shaped portion 3 to the other face S2. By bore- driving a punch 5 provided with a boring portion 5a for boring a bore having the same shape as the same shaped portion 3 and the plate 1, and a stepped portion 5b connected to the bored portion 5a and forming the tapered portion 4 by squashing obliquely the inner peripheral edge into the plate 1 placed on the dies 6 having the same center as the bored portion 5a and approximately the same shape as the same shaped portion 3, the caulking hole 2 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a nut caulking hole for mounting a nut on a plate-like body and a method for mounting a caulking nut.

[0002]

2. Description of the Related Art The applicant of the present invention has disclosed, for example, Japanese Patent Application No. 11-22 / 1990.
No. 479 proposes a nut fixing structure. For example, as shown in FIGS. 9A and 9B, a caulking hole b is previously formed in a plate-like body a, and a caulking nut c is attached to the caulking hole b. The caulking hole b is an equal-shaped part b1 that is connected in an equal shape from one surface of the plate-shaped body a.
And a tapered portion b2 whose size gradually increases from the inner end of the uniform portion b1 to the other surface.

The caulking nut c integrally has a nut base c1 having a screw hole d and a cylindrical portion c2 concentric with the nut base c1. Then, the cylindrical portion c2 is inserted into the caulking hole b from the isomorphic portion b1 side, and the portion where the cylindrical portion c2 extends from the isomorphic portion b1 to the tapered portion b2 is pressed by the caulking punch f. The diameter is expanded and pressed against the tapered portion b2 to cause plastic deformation. Thereby, the caulking nut c can be attached to the caulking hole b. The caulking nut c is supported concentrically with the caulking hole b by a nut holder g from below. In this manner, by attaching the nut to the plate-shaped member a in advance, the workability when attaching another member to the plate-shaped member a using a bolt or the like can be improved.

[0004]

By the way, as shown in FIGS. 10A and 10B, the caulking hole b has a punch i.
And a die j. The punch i is formed of a perforated portion i1 having an outer diameter D1 that is substantially the same shape as the uniform portion b1 and has an outer diameter D1 in an arbitrary vertical cross section including the axis. On the other hand, the die j has a die hole j1 having an inner diameter D2 larger than the outer diameter D1 in the cross section.

When forming the caulking hole b, the punch i and the die j are aligned concentrically, and the punch i is pressed against the plate-like body a. At this time, the inner diameter D2 of the die hole j1
And the difference between the outer diameter D1 of the punched portion i1 of the punch i,
It is possible to form a caulking hole b in which the uniform portion b1 is formed on the punch i side and the tapered portion b2 is formed on the die j side.

However, the caulking hole b configured as described above is formed by the tapered portion b2 formed by the punched portion i of the punch i.
Since the processed surface is torn as a result of the shearing force associated with the pushing of 1, the tapered portion b2 is hardly provided with sufficient processing accuracy. That is, there is a problem that the attachment of the caulking nut c becomes unstable, for example, a tapered portion having insufficient expansion or an irregular shape is formed. Further, in the conventional caulking hole forming method, there is a limit in increasing the spread angle of the tapered portion b2.

The present invention has been devised in view of the above-mentioned problems, and can improve the processing accuracy of the tapered portion and can make the tapered portion uniform, so that the caulking nut can be attached with good stability. It is an object of the present invention to provide a method for forming a hole and a method for mounting a caulking nut.

[0008]

The invention according to claim 1 of the present invention is a method for forming a caulking hole of a caulking nut in which a caulking hole for fixing a caulking nut is formed in a plate-like body. The hole has a shape portion that is continuous from the one surface of the plate-shaped body at right angles to the surface and is formed in the same shape, and a tapered portion whose shape gradually increases from the inner end of the shape portion toward the other surface. And a perforated portion having substantially the same shape as the isomorphic portion and perforating the plate-like body, and the tapered portion formed by obliquely crushing an inner peripheral edge of the perforated hole provided continuously with the perforated portion. Forming a punch having a stepped portion that forms a plate-shaped body placed on a die having a die hole concentric with the perforated portion and having the same shape as the uniform portion. It is characterized by forming.

According to a second aspect of the present invention, there is provided a method of mounting a caulking nut for fixing a caulking nut to a caulking hole formed according to the first aspect of the present invention, wherein a cylindrical portion formed on the caulking nut and concentric with a screw hole is provided. The tapered portion is inserted into the isomorphic portion and the extended portion where the tubular portion extends from the isomorphic portion to the tapered portion is formed by expanding the diameter with a caulking punch and pressing the tapered portion. It is characterized in that the caulking nut is fixed by being clamped between the nut base and the elongated portion.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. An embodiment of the method for forming a caulking hole of a caulking nut according to the present invention is schematically illustrated in FIGS. Figure 1
FIG. 1A is a cross-sectional view of a swaging hole 2 provided in a plate-like body 1 and FIG.
(B) shows a plan view thereof. The plate-like body 1 is made of a metal material, and its thickness, material, and the like are appropriately set as necessary. The caulking hole 2
Is formed from one surface S1 of the plate-like body 1 at a right angle to the surface S1 and continuous in an equal shape, and the shape is formed from the inner end 3a of the equal portion 3 toward the other surface S2. And a taper portion 4 that gradually increases in size. In the present example, an example composed of the equal-shaped portion 3 and the tapered portion 4 is illustrated. However, for example, due to the thickness of the plate-like body 1 and the like, the tapered portion 4 has a small length on the other surface S2 side. Other contours may be formed.

In the present embodiment, the uniform portion 3 is formed in a rectangular shape with four corners rounded. As described above, by making the shape of the equal-shaped portion 3 non-circular, it is preferable in that it serves to prevent a swaging nut to be described later from rotating. The tapered portion 4 is formed in a substantially rectangular shape whose contour on the other surface S2 is concentric with the isomorphic portion 3 and substantially enlarged at the same magnification. Is formed by joining the portion from to the uniform portion 3 with a tapered surface.

In the present invention, the caulking hole 2 is formed by using a punch 5 and a die 6 as shown in FIG. The punch 5 is provided at its tip with the caulking hole b
A hole 5a for drilling the plate-like body 1 having substantially the same shape as the contoured portion 3 and a stepped portion 5b connected to the rear end of the hole 5a and forming the tapered portion 4. are doing. The die 6 has a receiving surface 6b for supporting one surface S1 of the plate-like body 1 and a die hole 6a having an axis C2 concentric with the perforated portion 5a and having substantially the same shape as the uniform portion 3. are doing. In any vertical cross section including the axis C1 of the punch, the outer diameter D1 of the perforated portion is the same as that of the die hole 6 in the cross section.
It is formed to be the same as or slightly smaller than the inner diameter D2 of a. The outer diameter D3 of the stepped portion 5b in the cross section is larger than the inner diameter D2 of the die hole 6a.

[0013] In the caulking hole forming method of the present invention,
As shown in FIGS. 3 and 4, the punch 5 is inserted into the plate-like body 1 placed on the die 6 so that the caulking hole 2 is formed.
In this case, the stepped portion 5b forms the tapered portion 4 by obliquely crushing the inner peripheral edge 7 of the hole H formed by the perforated portion 5a. In this example, as shown in FIG. 4, the plate-like body 1 can be pressed between the stepped portion 5b and the receiving surface 6b of the die 6, and the crushing can be made more reliable. The tapered portion 4 formed by such a process
Can be pressed and deformed by being crushed under the compressive force and firmly sandwiched between the receiving surface 6b of the die 6;
Compared with the conventional method formed by shearing, the processing accuracy of the tapered portion 4 is improved, the shape thereof is made uniform, and the processed surface is beautifully finished. As a result, the mounting of the caulking nut c can be stabilized. The tapered portion 4 is also preferable in that the crystal structure becomes denser by pressing and the strength of the tapered portion 4 can be improved by work hardening. Further, since the tapered portion 4 is processed by crushing, the spread angle θ of the tapered portion 4 is easily increased, for example, 4
It can be greater than or equal to 0 degrees, thus helping to further enhance engagement with the swage nut (described below).

Next, a caulking nut attached to the caulking hole 2 is, for example, as shown in FIGS.
It comprises a nut base 9a having a screw hole 10 formed therein, and a cylindrical portion 9b formed concentrically and integrally with the screw hole 10. The outer shape of the cylindrical portion 9b is formed in a rectangular shape corresponding to the uniform portion 3. For this reason, the relative rotation of the cylindrical portion 9b inserted into the equal-shaped portion 3 with the plate-like body 1 can be effectively prevented. This prevents the caulking nut from rotating around when bolting. As described above, when the rotation with the plate-shaped body 1 is realized by using the cylindrical portion 9b, the head shape of the nut base 9a is a general hexagonal shape (shown by a broken line in FIG. 6). The present invention is not limited thereto, and may be formed in a square shape as shown by a broken line in FIG.

The cylindrical portion 9b has a circular inner hole 11 through which a bolt (not shown) and the like pass. The inner diameter D4 of the inner hole 11 is formed to be larger than the root diameter D5 of the screw hole 10. Thereby, a screw shaft such as a bolt (not shown) can easily enter the screw hole 10 through the inner hole 11 of the cylindrical portion 9b and be screwed. As a material of the nut base 9a, for example, a steel material that can be easily plastically deformed can be used as appropriate, in addition to, for example, ordinary nut and bolt steel.

The caulking nut 9 can be attached to the caulking hole 2 in the same procedure as in the prior art. That is, as shown in FIG. 8, the cylindrical portion 9b of the caulking nut 9 is inserted from the one surface S1 into the caulking hole 2 and the cylindrical portion 9b extends from the uniform portion 3 to the tapered portion 4. The expanded portion 9b2 is formed by caulking the portion 9b1 and expanding the diameter with the punch f and pressing the tapered portion 4 against the expanded portion 9b1. Thus, the tapered portion 4 can be fixed by being clamped between the nut base 9a of the caulking nut 9 and the extended portion 9b2. Further, at this time, since the tapered portion 4 is formed into a uniform shape and is firmly processed, the extended portion 9b2 can be reliably formed, and the caulking nut 9 can be attached with good stability.

[0017]

As described above, according to the first aspect of the present invention, caulking holes are formed by punching a punch into a plate-like body placed on a die. At this time, a step formed in the punch is formed. The attaching portion forms a tapered portion in the caulking hole by obliquely crushing the inner peripheral edge of the hole formed by the punching portion on the tip side of the punch. Since the tapered portion formed by such a process is crushed by receiving a compressive force, the processing accuracy of the tapered portion is improved and the shape thereof is made uniform, as compared with the conventional method formed by shearing. As a result, the machined surface is beautifully finished, and the installation of the caulking nut can be stabilized. Further, since the tapered portion is machined by crushing, the spread angle of the tapered portion can be easily increased, which further helps to further enhance the engagement with the caulking nut.

According to the second aspect of the present invention, the cylindrical portion of the caulking nut is pushed and expanded to the tapered portion using the caulking hole as described above, so that the cylindrical portion of the caulking nut is reliably tapered. It can be locked to the part, and the mounting property can be improved.

[Brief description of the drawings]

1A is a cross-sectional view of a caulking hole, and FIG. 1B is a plan view thereof.

FIG. 2 is a cross-sectional view illustrating a caulking hole forming method of the present invention.

FIG. 3 is a cross-sectional view illustrating a caulking hole forming method of the present invention.

FIG. 4 is a cross-sectional view illustrating a caulking hole forming method of the present invention.

FIG. 5 is a sectional view of a caulking nut.

FIG. 6 is a bottom view thereof.

FIG. 7 is a bottom view of a caulking nut showing another example.

FIG. 8 is a cross-sectional view showing a state where a caulking nut is attached to a caulking hole.

FIGS. 9A and 9B are cross-sectional views showing a conventional method of mounting a caulking nut.

FIGS. 10A and 10B are cross-sectional views showing a conventional method for forming a caulking hole.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 plate-shaped body 2 swaged hole 3 uniform part 4 tapered part 5 punch 5 a punched part 5 b stepped part 6 die 6 a die hole 6 b receiving surface 9 swage nut 9 a nut base 9 b tubular part

Claims (2)

[Claims] 1. A method for forming a caulking hole of a caulking nut for forming a caulking hole for fixing a caulking nut in a plate-like body, wherein the caulking hole is formed at a right angle from one surface of the plate-like body. And a tapered portion whose shape gradually increases from the inner end of the shaped portion toward the other surface, and the plate has substantially the same shape as the shaped portion. A punch having a perforated portion for perforating the body, and a stepped portion which is connected to the perforated portion and obliquely crushes an inner peripheral edge of the perforated hole to form the tapered portion, A method for forming a caulking hole of a caulking nut, characterized in that the caulking hole is formed by penetrating the plate-like body placed on a die having a concentric and substantially the same shape as the die hole. 2. A method for mounting a caulking nut to fix a caulking nut in a caulking hole formed according to claim 1, wherein a cylindrical portion formed in the caulking nut and concentric with a screw hole is inserted into the equal-shaped portion. And, by extending the cylindrical portion extending from the equal-shaped portion to the tapered portion, by expanding the diameter by a caulking punch and pressing the tapered portion, the tapered portion,
A method of mounting a caulking nut, wherein the caulking nut is fixed by being clamped between a nut base of the caulking nut and the extended portion.