JPH0550174A - Manufacture of machine parts - Google Patents

Abstract

PURPOSE:To provide manufacturing for machine parts, by which the machine parts, such as nut having wide-applicable range to plate thickness, is manufactured in low cost. CONSTITUTION:In the manufacturing for machine parts, plastic work making tip part of a cylindrical projecting part small diameter, is executed to form the small diameter part 25, and a large diameter part 26 projecting to outside is formed to a base of the above small diameter part 25 and an annular recessed position 28 is formed at near inside of the above large diameter part 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a mechanical part such as a nut, and more particularly to a method of manufacturing a mechanical part such as a crimp nut for fastening a plate-shaped member or interposing a member.

[0002]

2. Description of the Related Art A nut will be described below as an example.
The invention is not limited to nuts.

A so-called crimp nut provided with a cylindrical protrusion on the inside of the seat surface is used. The cylindrical protrusion is formed by backward extrusion or forward extrusion in the screw axis direction.

[0004]

When the nut provided with the above-mentioned cylindrical protrusion is crimped, the crimped portion is not flush with the lower surface of the plate, but rather deformed so as to be located below the lower surface of the plate. I often do it. For this reason, the applicable range for the plate thickness is small, and when fastening to a plate having an inappropriate thickness, inconvenience such as fastening failure occurs.

An object of the present invention is to provide a method for manufacturing a mechanical component, which eliminates such inconvenience and can manufacture a mechanical component such as a nut having a wide range of adaptation to the plate thickness at low cost.

[0006]

According to the present invention, a small diameter portion 25 is formed by performing a plastic working to make the tip of the cylindrical protruding portion 16 small in diameter, and a large diameter portion protruding outward at the base of the small diameter portion 25. The gist is a method of manufacturing a machine part, which is characterized in that a hollow 26 is formed and a return recess 28 is formed near the inside of the large diameter portion 26.

[0007]

The operation will be described with reference to the drawings. First, the cylindrical protrusion 16 shown in FIG. 4 is formed. Next, plastic working is performed to reduce the diameter of the tip of the cylindrical protrusion 16. That is, the so-called drawing process is performed, and as shown in FIG.
The small diameter portion 25 is formed by making the tip of the small diameter. Next, as shown in FIG. 6, a large-diameter portion 26 that protrudes outward at the base of the small-diameter portion and a return-shaped recess 28 near the inside of the large-diameter portion 26 are formed by plastic working that pressurizes in the axial direction. It The drawing process and the axial pressure plastic working may be performed at the same time.

When mounting this mechanical component, the small diameter portion 2
Attach 5 by caulking it to the mating member. At this time, the concave portion of the return letter acts as a caulking space and absorbs the extra thickness, so that the applicable range for the thickness of the mating member becomes large, for example.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A nut manufacturing method as one embodiment of the present invention will be described below with reference to the drawings.

The round bar material, which is the material of the nut, is sheared and the result is shown in FIG.
Many material pieces 10 shown in are obtained. Both ends of each piece are sheared surfaces.

The plastic working performed in the following first to fifth stations is cold forging (preferably performed in cold from an economical point of view), and is performed by, for example, a five-step (5-station) parts homer or a nut homer. You can In FIGS. 2 to 6, the upper side is the punch side and the lower side is the die side, but this may be reversed. Note that FIG.
6 is a cross-sectional view taken along two radii (corner portions and side portions of a hexagonal nut) orthogonal to each other in each molded body. 4 to 6
1, reference numerals 1, 1a and 1b are dies, 2 is a hole punch, 3 is a protruding pin, 4 is a center pin, 5 is a sleeve,
6 and 6a punches, 7 is a protruding sleeve, and 8 is another center pin.

End face shaping is performed at the first station. As a result, the end face of the material piece 10 of FIG. 1 is shaped to form the molded body 11 shown in FIG.

In the second station, preforming for punching is performed. As a result, the preliminary hole 13 is formed in the molded body 11 of FIG. 2, and the molded body 12 having the shape shown in FIG. 3 is obtained.

At the third station, punching and hexagonal molding are carried out to obtain a molded body 14 shown in FIG. That is,
The holes 15 are drilled and the cylindrical protrusions 16 are formed by front extrusion or rear extrusion. A shallow hole 17 is drilled on the opposite surface. In addition, the shallow hole side has a hexagonal shape 18
Is molded into.

At the fourth station, preforming of the caulking portion and hole penetration are performed. As a result, as shown in FIG. 5, the tip of the cylindrical protruding portion becomes the small diameter portion 20. Further, a through hole 23 is formed along the central axis. This step can be carried out by applying the tubular member manufacturing method disclosed in Japanese Patent Application No. 1-218640 filed by the present applicant.

The fifth station is for forming a large-diameter brim, a recess, and a triangular mountain serration. By pressure molding in the axial direction at the fifth station, a brim 26 (large diameter portion) protruding outward is formed at the base of the small diameter portion 25 as shown in FIG. The seat surface 2 is provided on the bottom of the brim 26.
7 is formed. In addition, a return-shaped recess 28 is formed near the inside of the brim 26. Further, about 40 triangular mountain serrations are formed on the outer peripheral surface of the small diameter portion 24, but they are omitted in FIG. 6 (see FIG. 7). The triangular mountain serration has an action of preventing relative rotation (incapability of screwing) of the plate and the nut when the screw is screwed into the nut.
The biting strength of the triangular mountain into the plate can be adjusted by the angle α and the length h of the caulking tool shown in FIG.

Finally, a caulking nut shown in FIGS. 7, 8 and 9 is obtained by forming an internal thread in a predetermined portion of the through hole with a tapping machine. Further, depending on the use of the crimp nut, surface treatment may be appropriately performed.

FIG. 7 shows an example of the geometrical dimensions of the nut before crimping.

10 and 11 show caulking tools 41 and 43 and plates 40 and 42 having wall thicknesses of 2 mm and 0.5 mm, respectively. At the time of crimping, the deforming pressure is applied from the lower side of the drawing by using the crimping tools 41 and 43. Height of caulking part 0.1
5d is set based on the plate thickness.

At the time of mounting, the caulked portion is made flush with the surface of the plate or is dented from the plate surface so that the components to be mounted are in close contact with the plate surface. Then, the protrusion of the caulking portion is plastically caulked to the same plane as the plate by the pressure applied to the caulking tool, and the pressed surplus is pushed into the recess.

FIG. 12 shows an example of the nut 50 when the crimping pressure at the time of manufacture is lowered. In this case, the recess 51 is formed slightly larger.

[0022]

According to the present invention, the small diameter portion 25 is formed by performing the plastic working for reducing the diameter of the tip of the cylindrical protruding portion 16, and the large diameter portion 26 protruding outward is formed at the base of the small diameter portion 25. ,
Since the method of manufacturing a mechanical component is characterized in that a return-shaped recess 28 is formed in the vicinity of the inside of the large-diameter portion 26, a highly versatile mechanical component can be manufactured at low cost.

Here, high versatility means that, for example, the range of adaptation to changes in plate thickness is wide. High versatility is obtained by pressing the inner wall of the hole of the plate on which the nut is to be mounted and allowing the excess thickness to flow into the recess.

The molding process (the fourth and fifth in the previous embodiment)
By appropriately setting the shape and volume of the recess provided in the nut (corresponding to the station), it is possible to realize the crimping strength according to the change of the material.

The present invention is not limited to the above embodiment. For example, the fourth and fifth stations may be performed in a series of operations to form the small diameter portion, the brim, and the recess almost at the same time. Further, the present invention can be applied not only to nuts but also to manufacture pipes, collars, spacers and the like.

[Brief description of drawings]

FIG. 1 is a sectional view showing a material piece according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a molded body in the first station according to the embodiment of the present invention.

FIG. 3 is a sectional view showing a molded body in the second station according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a molded body in a third station according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a molded body at a fourth station according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a molded product at a fifth station according to the embodiment of the present invention.

FIG. 7 is a side view showing a cross section of one side of a nut molded according to the present invention.

FIG. 8 is a top view of the nut of FIG.

9 is an end view of the nut of FIG. 7 as seen from the lower surface.

FIG. 10 is a cross-sectional view showing a crimped state of a nut manufactured according to an embodiment of the present invention.

11 is a diagram in which the plate thickness is changed in FIG.

FIG. 12 is a side view of another nut formed according to the present invention with a cross section taken only on one side.

[Explanation of symbols]

 16 Cylindrical protrusions 25, 34, 54 Small diameter parts 26, 32, 32 Large diameter parts 28, 31, 51 Return recesses 30, 50 Nuts 24 Molded bodies ◆

Claims (1)

[Claims] 1. A small diameter portion (25) is formed by performing a plastic working for reducing the tip of the cylindrical protrusion (16) to a small diameter, and a large diameter portion (26) protruding outward at the root of the small diameter portion (25). ) Is formed, and a concave portion (2) is formed near the inside of the large diameter portion (26).
8) A method for manufacturing a machine part, characterized by molding.