JP2595910Y2 - Punch for upsetting joining of thin metal plates - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punch for upsetting and joining thin metal sheets.

[0002]

2. Description of the Related Art As an integrated apparatus for joining thin metal sheets instead of welding, two or more superposed thin metal sheets are pushed into the upset holes of a die with a punch to form an embossed joint. There is known a method of pressing the space.

Hereinafter, the structure and operation sequence of the conventional apparatus will be described with reference to FIG. The upsetting joining device (8) is shown in FIG.
As shown in (A), a support surface (5B) for two thin metal sheets (1) and (2) is provided, and a bottomed cylindrical upset hole (5A) is arranged below the support surface (5B). Die (5)
A cylindrical punch (7) arranged coaxially with the upset hole (5A) and capable of ascending and descending above the support surface (5B).
A cylindrical stripper (6) slidably inserted at the tip of the punch (7); and a coil spring (4) mounted around the punch (7) as a means for applying a pressing load to the stripper (6). ).

[0004] In the upsetting joining of the metal sheets (1) and (2), first, as shown in FIG.
The metal sheets (1) and (2) are placed on top of each other in a superposed state, and the bottom surface of the stripper (6) is brought into close contact with the upper surface of the metal sheet (1), and transmitted from the coil spring (4) in this state. By applying a pressing load, the die (5)
The metal thin plates (1) and (2) are positioned and fixed on the surface.

Next, as shown in FIG. 2 (B), a hydraulic drive device (not shown) is activated to generate a downward stroke on a punch (7) mounted on the tip thereof. Punch (7)
Moves down while sliding against the shaft hole of the stripper (6) against the restoring force of the coil spring (4), and moves the tip end (7A) of the stripper (6) into the upset hole (5) provided in the die (5).
A). Thereby, the upset hole (5A)
The metal sheets (1) and (2) located above are pushed into the upset holes (5A) while maintaining the superposed state,
This part is embossed upset joint site (1A) (2
A).

After the embossed joints (1A) and (2A) are formed on the two metal sheets (1) and (2), FIG.
As shown in (C), the hydraulic drive device (not shown) is reversely started to generate a rising stroke in the punch (7). The rise of the punch (7) raises the metal thin plates (1) and (2) while keeping the inner peripheral side wall surface of the embossed upset joint portion (1A) in contact with the outer peripheral side wall surface of the punch (7). The upset joints (1A) and (2A) of the
Pull up above A). Since the metal sheets (1) and (2) are pressed downward by the coil spring (4) via the stripper (6), the upset joint portion (1A)
Immediately after lifting (2A) upward, the embossed joining portions (1A) and (2A) of the metal sheets (1) and (2) are separated from the tip (7A) of the punch (7), and a series of upsetting joining operations is completed. I do.

[0007]

In the conventional device (8) shown in FIG. 2, a punch (7) has a tip (7A).
From the base end (7B) to the front end (7A) of the punch (7), the embossed upset joints (1A) (2A) are formed with respect to the tip (7A) of the punch (7). Pressure contact with a relatively large contact area. For this reason, the punch (7)
A biting phenomenon occurs due to a strong pressing load between the tip (7A) of the steel sheet and the embossed upset joint, and it is difficult to release the thin metal plates (1) and (2) from the punch (7). Becomes In order to avoid this problem, it is conceivable to increase the spring pressure of the coil spring (4). However, in this case, the descending reaction force of the punch (7) increases, which increases the power consumption and the size of the device. Inconvenience occurs.

[0008]

According to the present invention, as a means for solving the above-mentioned problems, there is provided a punch which pushes two or more superposed thin metal sheets into a set-up hole of a die and inserts and joins into an integrated structure. and forming a reverse tapered reduced diameter portion position which tapers toward the base end portion between the tip portion and the proximal portion, about the axial direction at the tip portion of the punch 2m
m, forming a cylindrical pressing part with a thickness of
In this case, the thin metal plate is
A punch for upsetting joining of a thin metal plate, characterized in that the punch is spread outward in the radial direction so as not to be stuck.

[0009]

By forming an inversely tapered diameter-reduced portion which becomes narrower toward the proximal end portion between the distal end portion and the proximal end portion of the punch, the distal end portion of the punch can be moved during the downward stroke and the upward stroke of the punch. The press contact area between the metal sheet and the embossed joint of the metal sheet is reduced, and the metal sheet is easily released from the tip of the punch.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In the following description, the same components as those in FIG. 2 showing the related art are denoted by the same reference numerals, and the description of the same items will not be repeated.

The punch (3) used in the upsetting device (9) according to the present invention is placed on the support surface (5B) of the die (5) in an overlapping state as shown in FIG. Two metal sheets placed, for example, aluminum sheets (1) (2)
In addition, the tip of the punch (3) for applying a compressive load for upsetting joining is relatively thin in the axial direction, for example, about 2 mm.
An intermediate body portion of the punch (3) formed at the cylindrical pressing portion (3A) having the thickness (L) and extending from the pressing portion (3A) toward the small-diameter base end portion (3B), It is formed in a non-press-contact section (3C) composed of an inversely tapered reduced diameter portion (taper angle is indicated by θ). The small-diameter base end (3B) is chamfered with a predetermined radius of curvature (R) to avoid stress concentration when a compressive load is applied.

Next, the operation of the joining device (9) will be described. First, as shown in FIG. 1 (A), thin aluminum plates (1) and (2) are positioned and fixed on a die (5) in a superimposed state by using pressure by a stripper (6). Next, as shown in FIG. 1 (B), a hydraulic drive device (not shown) is activated, and a downward stroke is generated in the punch (3) mounted on the tip thereof. The tip portion (3A) of the punch (3) descends while slidingly contacting the shaft hole of the stripper (6) against the restoring force of the coil spring (4), and the upset hole provided in the die (5). The aluminum thin plates (1) and (2) are pushed into (5A). As a result, embossed upset joint portions (1A) and (2A) are formed in the aluminum thin plates (1) and (2).

Finally, as shown in FIG. 1 (C), a hydraulic drive device (not shown) is reversely started to generate a rising stroke in the punch (3). Due to the rise of the punch (3), the aluminum thin plates (1) and (2) press the inner peripheral side wall surface of the embossed upset joint (1A) against the outer peripheral side wall surface of the cylindrical pressing portion (3A) of the punch (3). The embossed upsetting joints (1A) and (2A) are lifted above the upsetting holes (5A) while being raised. In the upsetting joining device (9) according to the present invention, the intermediate body (3C) extending from the cylindrical pressing portion (3A) of the punch (3) toward the small-diameter base end (3B) is attached to the base (3C). The intermediate body (3C) and the embossed upset joint (1) are formed in the reverse taper-shaped reduced diameter portion whose diameter gradually decreases toward the end.
A) and a certain gap is secured. As a result, at the time of the downward stroke and the upward stroke of the punch (3), only the outer periphery of the cylindrical pressing portion (3A) at the tip of the punch (3) is the embossed upset joining portion ( 1A) is pressed against the inner peripheral surface, and the pressed area of the entire punch (3) is greatly reduced.
Accordingly, the punch (3) and the aluminum thin plates (1) and (2) are prevented from being bitten at the time of release, and the aluminum thin plate (1) is restored by the restoring force of the coil spring (4).
(2) is released. Even if the intermediate body part (3C) comes into contact with the joint part (1A), the contact pressure is considerably smaller than before, so that the aluminum thin plate (1)
It does not hinder the release of (2).

[0014]

[Effects of the Invention] In the present invention, since the diameter of the tapered portion in the reverse taper is formed at the tip of the punch, the contact area with the thin metal plate at the time of upset joining can be reduced, and the punch bites into the thin metal plate. Can be prevented, and the punch can be easily pulled out. Further, according to the present invention, a practically satisfactory releasability can be ensured without increasing the spring pressure of the coil spring (4). Upsizing is also avoided. As a result, a remarkable effect is exerted on the improvement of the productivity and the simplification of the apparatus.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are front views of an upsetting apparatus for explaining an operation sequence of an upsetting punch according to the present invention;

2 (A), 2 (B), and 2 (C) are front views of an upsetting apparatus for explaining the operation sequence of a conventional upsetting punch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal thin plate 2 Metal thin plate 3 Punch 3A Cylindrical trapezoidal pressing part 3B Small diameter base end part 3C Reverse taper-shaped reduced diameter part (non-pressing section, middle body part) 4 Coil spring 5 Die 5A Uphole 6 Stripper 9 Upset joining equipment

Claims (1)

(57) [Scope of request for utility model registration] 1. A punch which presses two or more superposed metal thin plates into an upset hole of a die and upsets and joins them into an integral structure, wherein the base end portion is located between a distal end portion and a base end portion of the punch. When forming a reverse tapered reduced diameter portion that becomes thinner toward
The tip of the punch has a thickness of about 2 mm in the axial direction.
Form a cylindrical pressing part with
Do not allow the metal sheet to bite into the reduced diameter area at the pressed area
A punch for upsetting joining of thin metal sheets, characterized in that the punch is spread outward in the radial direction .