JPH07139532A - Nut joining structure - Google Patents

Abstract

PURPOSE:To join a nut to a base material so that the shear strength at a caulked part is excellent and the nut does not project from the base material. CONSTITUTION:A metallic nut 10 with a lateral groove formed on the outside is enaged with a nut engaging hole 21 formed on a base material 20 made of a metal capable of being caulked, a standing wall 22 circumferentially provided on the circumferential edge of the nut engaging hole 21 is crushed in the lengthwise direction by a punch so as to squeeze a part of the plastically deformed standing wall 22 in the lateral groove 14, and hence the nut 10 and the base material 20 are joined together into one body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut joining structure in which a metal nut is caulked and fixed to a metal base material.

[0002]

2. Description of the Related Art As a conventional technique of this kind, a pierce nut as shown in FIG. 10 is generally known. This is provided with a lateral groove 2 on the opposing outer surface of a rectangular nut 1, and by crimping the peripheral edge portion of the nut engaging hole 4 of the base material 3 to the lateral groove 2, the nut 1 and the base material 3 are integrally joined. Has been done.

11 (a), 11 (b) and 11 (c) are shown in FIG.
It is a figure explaining the process of joining the pierce nut 1 shown in FIG. First, as shown in FIG. 11A, the nut 1
To the die 5 having a rectangular hole 6 aligned with the base material 3
11B, the nut 1 positioned above the base material 3 is pressed down by the plunger 7 so that the edge corner portion 1a of the nut 1 and the die 5 are engaged with each other. The base material 3 is sheared at the nut contour matching position by the hole peripheral edge corner portion 5a. Next, as shown in FIG.
By pressing the cut edge portion of the base material 3 with the rib 5b formed on the periphery of the hole 6 on the die 5 side and the flange 1b on the nut side, and swaging the cut edge portion in the lateral groove 2 of the nut 1, The nut 1 is joined and integrated with the base material 3.

[0004]

However, in the above-mentioned conventional joining structure, the cutting edge of the base material 3 is crushed in the plate thickness direction so that the cutting edge of the base material 3 is lateral groove 2 of the nut 1. As they enter and are caulked and fixed to each other, the thickness d in the shearing direction of the caulking portion becomes equal to or less than the plate thickness t (see FIG. 10), so that the joint is applied to the load acting in the axial direction of the nut. There is a problem that the shear strength of the part is weak.

Further, since the end edge corner portion 1a of the nut 1 has a function of shearing the base material 3, it is sharp at a right angle and may be injured by touching. Furthermore, FIG.
As shown in, the bolt 8 is screwed into the pierce nut 1 to fix the member 9 to be fastened, but the cut end portion of the base material 3 is caulked and fixed to the lateral groove 2 of the nut 1. ,
Since the nut 1 projects from the base material 3, the base material 3 cannot be in contact with the fastened member 9. In order to make the base material 3 and the member 9 to be fastened flush with each other, as shown in FIG. 13, the peripheral area 3b of the nut 1 may be embossed, but the number of steps is increased and the processing is troublesome. There's a problem.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a nut joining structure which is excellent in shear strength at a crimped portion and which can be joined in a form in which a nut does not protrude from a base material. It is in.

[0007]

In order to achieve the above object, in the nut joining structure according to claim 1, a nut engaging hole formed in a base material made of a crimpable metal is provided with an outer surface. The metal nut having the lateral groove formed therein is engaged with the vertical wall, and the standing wall circumferentially provided around the periphery of the nut engaging hole is crushed in the vertical direction, so that a part of the plastically deformed standing wall enters the lateral groove and the nut member is formed. The base material and the base material are joined and integrated.

[0008]

When the groove width of the lateral groove of the upright wall is equal to or larger than the plate thickness, the thickness of the caulking portion in the axial direction of the nut can be equal to or larger than the plate thickness, and the shear strength of the joint portion can be increased accordingly. Also, a part of the vertical wall that has been crushed and plastically deformed enters the lateral groove of the nut to join the nut and the base material, so that the nut does not protrude from the surface of the base material on the side where the vertical wall is not formed. Can be configured.

Unlike the pierce nut, the nut does not need to have a function of shearing the base material. Therefore, it is not necessary to sharply form the edge corner portion of the nut, which is safer for the operator.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 7 show an embodiment of a nut joint structure according to the present invention. FIG. 1 is a perspective view of a nut joint portion, and FIG.
Is a vertical cross-sectional view of the nut joining portion, FIG. 3 is a plan view of the nut joining portion, FIG. 4 is a vertical cross-sectional view of a joining device for joining a nut to a base material, and FIG. 5 is placed on a base of the joining device. 6 is a perspective view showing how the nut is positioned in the standing wall of the formed base material, FIG.
FIG. 7 is a perspective view of a punch tip that plastically deforms the standing wall, and FIG. 7 is a cross-sectional view illustrating the operation of the joining device.

In these drawings, reference numeral 10 is a cylindrical metal nut having an internal thread portion 12 formed on the inner periphery thereof, and a base material 2 described later is provided at four circumferential positions on the outer peripheral surface of the nut 10.
A lateral groove 14 having a groove width W larger than the plate thickness t of 0 is formed. Reference numeral 16 is a cross-shaped V groove provided on the lower end surface of the nut 10 and extending in the radial direction.
It is a positioning groove for positioning the lateral groove 14 of the nut 10 with respect to the protruding tip portion 46 at one place.

A circular hole 21 matching the outer shape of the nut 10 is provided in the base material 20, and a peripheral wall 22 raised by drawing is provided around the peripheral edge of the circular hole 21. While the nut 10 is engaged in the standing wall 22,
A position of the standing wall 22 corresponding to the lateral groove 14 is pressed in the axial direction, and a part of the vertically deformed standing wall 22 enters the lateral groove 14,
The standing wall 22 and the nut 10 are joined and integrated.

Since the thickness W of the portion 22a of the standing wall 22 that joins the nut 10 and the base material 20 into the lateral groove 14 of the nut 10 is larger than the plate thickness t of the base material 20, FIG.
It can be said that the shear strength against the force acting in the axial direction of the nut is higher than that of the conventional joint structure using the pierce nut shown in FIG. To join the nut 10 to the upright wall 22, see FIG.
Use the joining device shown in.

Reference numeral 30 in FIG. 4 is a base for carrying the base material 20, and a base material carrying surface 31 of the base 30 has a triangular cross section at the center of the base material carrying surface 31 which engages with the V groove 16 of the nut 1a at the head end surface. The bolt 32 provided with the ridge portion 33 is screwed. Reference numeral 40 denotes a ram that can be moved up and down, and the ram 40 is urged downward by a compression coil spring 42 so that the nut 1
A cylindrical pressing member 41 having an outer shape matching the outer shape of 0,
A cylindrical pressing member 43 having an inner diameter that is urged downward by a compression coil spring 44 and engages with the outer shape of the standing wall 22.
And has the same cross-sectional shape as the standing wall 22, is fixed to the ram 40, and is interposed between the pressing members 41 and 43,
A cylindrical punch 45 that is slidable in the axial direction relative to both members 41 and 43 is provided.

As shown in FIG. 6, the tip of the punch 45 is formed in a shape in which four circumferentially equally divided positions project in an arc shape, and this projecting portion 46 pushes the standing wall 22 in the axial direction. A part of the vertical wall 22 that is crushed and plastically deformed by this is inserted into the lateral groove 14, and the vertical wall 22 and the nut 10 are joined. When the punch 45 crushes the standing wall 22, the holding member 41 holds the nut 10 and the holding member 43 surrounds the standing wall 22 of the base material 20 around the base material carrying surface 31 of the base 30.
The nut 10 and the base material 20 are prevented from rotating relative to each other by pressing.

Next, the procedure for joining the nut 10 to the standing wall 22 of the base material 20 will be described with reference to FIGS. First, a circular hole 21 and a standing wall 22 having a predetermined height are formed in the base material 20 by drawing in advance. Next, as shown in FIG. 4, the base material 20 is placed on the base material carrying surface 31 of the base 30. At this time, the base material 20 is positioned so that the ridges 33 projecting from the base material carrying surface 31 of the base 30 are located inside the standing wall 22, so that the base material 20 is automatically positioned with respect to the base material carrying surface 31. It Next, the nut 10 is inserted into the standing wall 22 from above the standing wall 22, the V groove 16 is aligned with the protruding portion 33, and the nut 10 is positioned in the circumferential direction. Next, when the ram 40 is lowered, the pressing members 41 and 43 are moved to the nut 1
0, the base material 20 is pressed against the base 30, the punch 45 is pressed down, the protruding end portion 46 of the punch 45 axially crushes the standing wall 22, and a part of the plastically deformed standing wall 22 enters the lateral groove 14 and stands up. 22 and the nut 10 are joined.

8 and 9 show a nut joint portion according to a second embodiment of the present invention, FIG. 8 is a perspective view of the nut joint portion, and FIG. 9 is a plan view of the nut joint portion. First mentioned above
In the embodiment of the above, the lateral grooves 1 are provided at four positions equally divided in the circumferential direction of the nut 10.
4 was formed, the nut 10A in the present embodiment
Then, since the lateral groove 14A is provided around and the entire circumference of the nut 10A is joined by the standing wall 22, it can be said that the shear strength against a load acting in the axial direction of the nut is high. Others are the same as those in the first embodiment described above, and the description thereof will be omitted by giving the same reference numerals.

Needless to say, the punch used in the structure of this embodiment is of a cylindrical type having a tip portion capable of uniformly pressing the tip surface of the standing wall 22. Also, the above 2
In each of the embodiments, the nuts 10 and 10A are formed in a cylindrical shape, but the nuts are not limited to the cylindrical shape, and may be a commonly used hexagonal nut. In the case of a hexagonal nut, it is sufficient to provide a plurality of lateral grooves on the outer surface of the existing hexagonal nut or to provide a circumferential groove. When the existing nut is processed and used, the cost of the nut can be reduced by that much. .

[0019]

As is apparent from the above description, according to the nut joining structure of the present invention, the thickness of the caulking portion in the nut axial direction is set by setting the groove width of the lateral groove of the standing wall to the plate thickness or more. Can be made thicker than the plate thickness, whereby a nut joint structure with high shear strength can be obtained. Further, in the present invention, the nut can be configured not to project from the surface of the base material on the side where the standing wall is not formed without embossing the base material. Can be attached closely to the base material.

Further, unlike the conventional pierce nut, it is not necessary to form the edge corner portion into an acute angle shape, so that the processing accuracy of the edge edge corner portion is not required and the operator is not injured even if touched, which is safe. Is.

[Brief description of drawings]

FIG. 1 is a perspective view of a nut joint portion having a nut joint structure according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the nut joint portion.

FIG. 3 is a plan view of the nut joint portion.

FIG. 4 is a vertical sectional view of a joining device for joining a nut to a base material.

FIG. 5 is a perspective view showing how the nut is positioned in the standing wall of the base material placed on the base of the joining device.

FIG. 6 is a perspective view of the punch tip that plastically deforms the standing wall.

FIG. 7 is a cross-sectional view illustrating the operation of the joining device.

FIG. 8 is a perspective view of a nut joint portion according to a second embodiment of the present invention.

FIG. 9 is a plan view of the nut joint portion.

FIG. 10 is a perspective view of a nut joint portion using a pierce nut which is a conventional technique.

FIG. 11 is an explanatory diagram illustrating a procedure for joining a pierce nut to a base material.

FIG. 12 is a sectional view showing a state in which another member is bolted to the pierce nut joint portion.

FIG. 13 is a sectional view showing a state in which other members are fastened to the base material embossed around the pierce nut with bolts and nuts.

[Explanation of symbols]

 10, 10A nut 14, 14A lateral groove 20 base material 21 circular hole which is a nut engagement hole 22 standing wall 45 punch 46 protruding end of punch

Claims (1)

[Claims] 1. A nut made of metal capable of being caulked is engaged with a nut engagement hole formed in a base material, and a metal nut having a lateral groove formed on its outer surface is engaged with the nut engagement hole. A nut joining structure characterized in that the provided standing wall is crushed in the vertical direction, and a part of the plastically deformed standing wall enters the lateral groove to join and integrate the nut member and the base material.