JPH10305335A - Joint of metal plate and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for joint of metal plates to improve a life of punch and die. SOLUTION: The method for joint of metal plates comprises plastic deformating, with the punch 1 and die 2, two metal thin plates 3 and 4 contacting with the faces and press/expanding, to the radial direction, the bottom of the thin plate 3 at the punch 1 side to bind it to the cavity of the thin plate 4 at the die 2 side, wherein an inclined cavity 5 denting at the center is arranged at the tip part of the punch 1 and an inclined convex 6 projecting at the center is arranged at the bottom of the die 2 and the inclined angle of the covex 6 is arranged to be larger than the inclined angle of the cavity 5, so as to smoothly raise a plastic flow directing from the center to the edge under a pressure less than that to collapse them at a flat part and to uniformly disperse the load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for joining metal plates by mechanical joining in sheet metal working.

[0002]

2. Description of the Related Art In recent years, in sheet metal processing, a processing method using a coated steel plate and omitting a coating step has been performed. At the time of joining these metal plates, welding cannot be performed due to the presence of the coating film, and joining by mechanical joining such as caulking is mainly employed.

A conventional joining method and apparatus disclosed in Japanese Patent Application Laid-Open No. 62-77130 will be described below with reference to FIG. In FIG. 4, 21 is a punch, 22 is a die,
23 and 24 are thin plates to be joined. The center of the tip of the punch 21 is slightly protruded, the bottom of the die 22 is flat, and an annular recess 25 is formed on the outer periphery. And
The thin plates 23 and 24 are stacked and placed on the die 22 and the punch 2
When the sheet 1 is lowered, the punch 21 crushes the thin plates 23 and 24 and pushes the thin plates 23 and 24 toward the bottom of the die 22. At the bottom, the thin plate 23 that has plastically flowed in the radial direction is placed behind the thin plate 24 that has also plastically flowed. Thin plate 2 by entering
The combination of 3 and 24 occurs.

[0004]

However, in the above-mentioned conventional structure, a sufficient surface pressure is required to generate a plastic flow between the tip of the die 22 whose central portion is slightly protruded and the bottom of the flat die 22. 5, a concentrated load is applied to the tip 21a of the punch 21 and a point 22a at the center of the bottom of the die 22 as shown in FIG. 5, so that a crack 26 occurs in the punch 21, a buckling 27 occurs, Die 2
2, a depression 29 shown by a broken line, a chip 30 shown by a diagonal line, etc.
In addition, there is a problem that the life of the die 22 is short.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a method and an apparatus for joining metal plates that can extend the life of a punch and a die.

[0006]

According to the method of joining metal plates of the present invention, two overlapping thin plates are plastically deformed by a punch and a die, and the bottom of the thin plate on the punch side is radially expanded in a radial direction. In the method of joining a metal plate to be bonded to a concave portion of a thin plate on the die side, a central portion is inclined between the tip of the punch and the bottom of the die so as to protrude toward the punch, and a cross-sectional height increases from the central portion to the peripheral portion. Plastic flow occurs in the molding space, and the molding space has a larger cross-sectional height toward the peripheral edge, and the center of the molding space is inclined so as to protrude toward the punch. Because the component force acts effectively, plastic flow is generated smoothly from the center to the peripheral portion, and plastic flow can be generated smoothly with a smaller pressing force than crushing in a flat molding space Since pressure in the broad range of molding spaces at the bottom of the punch tip and die does not act is concentrated load dispersed can prolong the life of the punch and die.

A metal plate joining apparatus according to the present invention is a metal sheet joining apparatus in which two overlapping thin plates are plastically deformed and joined to each other by a punch and a die. An inclined concave portion is provided, an inclined convex portion having a central portion protruding is provided at the bottom of the die, and an inclined angle of the inclined convex portion is set to be larger than an inclined angle of the inclined concave portion. The pressing force is applied on the circumference, and during the crushing, the pressing force is dispersed over a wide range of the inclined concave portion of the punch and the inclined convex portion of the die, and the component force in the radial direction is large because the inclination angle of the inclined convex portion of the die is large. As a result, plastic flow occurs smoothly from the center to the periphery,
When caulking is completed, the pressing force is dispersed over almost the entire surface of the punch and die processing parts, so that plastic flow can be generated smoothly with a smaller pressing force than crushing at the flat part, and the pressing force is dispersed. Since concentrated load does not act,
The service life of the punch and the die can be extended.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method and an apparatus for joining metal plates according to the present invention will be described below with reference to FIGS.

In FIG. 1, 1 is a punch, 2 is a die,
Reference numerals 3 and 4 are thin plates to be joined. At the tip of the punch 1, an inclined concave part 5 whose central part is dented is formed, and at the bottom of the die 2, an inclined convex part 6 whose central part protrudes is formed. Assuming that the inclination angle of the inclined concave portion 5 with respect to the horizontal plane is a and the inclination angle of the inclined convex portion 6 with respect to the horizontal plane is b, the angle b is set to be larger than the angle a by the angle c as shown in FIG.

With the above configuration, when the punch 1 enters, the load 7 of the pressing force is on the circumference of the outer periphery of the punch 1 as shown in FIG. Distributed. Next, during the crushing, as shown in FIG. 2, the regions 8 and 9 to which the pressing force is applied move toward the inclined surfaces of the inclined concave portion 5 of the punch 1 and the inclined convex portion 6 of the die 2 and have a wide range. Are distributed. Further, since the inclination angle b of the inclined convex portion 6 of the die 2 is large, the component force in the radial direction is increased, and plastic flow occurs smoothly from the center to the edge. Furthermore, upon completion of swaging,
As shown in FIG. 3, in the regions 10 and 11 to which the pressing force is applied, the pressing force is dispersed over substantially the entire processing portion of the punch 1 and the die 2. Therefore, a plastic flow can be smoothly generated with a smaller pressing force than crushing in a flat portion,
Since the pressure is dispersed and no concentrated load acts, the service life of the punch 1 and the die 2 can be extended.

In the above-described embodiment, an example is shown in which the inclined recess 5 is formed at the tip of the punch 1. However, the tip of the punch 1 may have a flat shape and only the inclined convex 6 may be provided on the bottom surface of the die 2.

[0012]

According to the metal plate joining method and apparatus of the present invention, as is apparent from the above description, the forming space between the tip of the punch and the bottom of the die has a larger sectional height toward the peripheral portion, In addition, since the central portion of the molding space is inclined so as to protrude toward the punch side, a radial component force effectively acts, so that plastic flow smoothly occurs from the center portion to the peripheral portion, and a small amount of force is applied. The plastic flow can be smoothly generated by pressure, and the pressure is dispersed over a wide area of the molding space between the punch tip and the bottom of the die, so that concentrated load does not act and the life of the punch and the die is extended. Can be.

Further, according to the metal plate joining apparatus of the present invention, an inclined concave portion whose central portion is recessed is provided at the tip of the punch, an inclined convex portion whose central portion protrudes is provided at the bottom of the die, and the inclined concave portion is provided. Since the inclination angle of the inclined convex portion is set to be larger than the inclined angle, a pressing force is applied on the circumference of the punch outer periphery when the punch enters, and the inclined concave portion of the punch and the inclined convex portion of the die are wider during the crushing. Since the pressing force is dispersed in the range and the inclination angle of the inclined projection of the die is large, the component force in the radial direction increases, and plastic flow occurs smoothly from the center to the periphery, and the punch and Since the pressing force is dispersed over almost the entire processing area of the die, plastic flow can be generated smoothly with a smaller pressing force than crushing at the flat portion, and the pressing force is dispersed and concentrated load does not act So punch It can prolong the life of the die.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an initial stage of a process in an embodiment of a metal plate joining method according to the present invention.

FIG. 2 is a cross-sectional view in the middle of a step in the embodiment.

FIG. 3 is a cross-sectional view at the time of completion of a process in the embodiment.

FIG. 4 is a cross-sectional view of a conventional method for joining metal plates.

FIG. 5 is an explanatory diagram of a problem of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Punch 2 Die 3 Thin plate 4 Thin plate 5 Inclined concave portion 6 Inclined convex portion

Claims (2)

[Claims] 1. A joining method of a metal plate in which two overlapping thin plates are plastically deformed by a punch and a die, and the bottom of the thin plate on the punch side is radially expanded and connected to a concave portion of the thin plate on the die side. Wherein a plastic flow is produced in a molding space in which a central portion is inclined between the tip of the punch and the bottom of the die so as to protrude toward the punch side, and a sectional height increases from the central portion toward the peripheral edge. How to join metal plates. 2. A joining apparatus for a metal plate in which two overlapping thin plates are plastically deformed and joined to each other by a punch and a die, an inclined concave portion having a central portion recessed at the tip of the punch, and a central portion formed at the bottom of the die. An apparatus for joining metal plates, characterized in that an inclined convex portion from which a portion protrudes is provided, and an inclined angle of the inclined convex portion is set larger than an inclined angle of the inclined concave portion.