JPH105888A - Method and device for sheet metal work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a plurality of shafts on a chassis at one time by a press die by pressing a bottom surface of a corresponding recessed part to form a projected part into a cylindrical projected body while the pressing force is applied to a top surface of a projected part. SOLUTION: A stock sheet of uniform thickness (t) over the whole surface is used as a sheet metal 1 to be worked. A recessed part 2 is formed on one surface side from the sheet metal 1, and at the same time, a projected part 3 is formed in a raised manner on the other surface side to make an intermediate formed article 4. A cylindrical projected body 5 is erected on the projected part 3 to form a final formed article 6 by pressing a bottom surface 2a of the recessed part 2 while the pressing force is applied to a top surface 3a of the projected part 3. In a case of a chassis such as one for VTR, 5-8 projected bodies 5 (shaft-shaped bodies) which are different in outer diameter and height are provided. The cost can be greatly reduced compared with the conventional working method where a shaft-shaped body is implanted one by one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet metal working method and a sheet metal working apparatus for forming a cylindrical projection on a chassis of precision equipment or the like.

[0002]

2. Description of the Related Art Conventionally, in order to provide a rotating body (lever, arm, etc.) or a rotating body (gear, roller, rotation transmitting body) shaft on a sheet metal chassis of precision equipment such as a VTR, audio equipment, computer equipment, etc. The most common method is to establish a shaft formed by processing on the sheet metal chassis by screwing or caulking.

In the case of a shaft having a low height, a technique of forming the shaft from a sheet metal material for a chassis by press molding has been put to practical use.

[0004]

However, in the processing method by screwing or crimping, there are problems that the steps are complicated in many ways and that an increase in cost is unavoidable. Further, as described above, a technique of forming a shaft from a sheet metal material by integral molding has been put to practical use, but it is impossible with the conventional technique to raise the thickness of the sheet metal material only at a position where an axis is to be established. Therefore, the rising height from the chassis sheet metal (shaft height) is 2
There is a problem that only a product as low as about three times can be realized, and the use of the molded shaft is limited.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is possible to form a sheet-like material having various shaft heights higher than a sheet metal thickness by sheet metal integral molding. An object of the present invention is to provide a working method and a sheet metal working apparatus.

[0006]

In order to achieve the above-mentioned object, a sheet metal working method according to the present invention comprises:
A sheet metal working method in which a sheet metal is sandwiched between an upper mold and a lower mold to form a cylindrical protruding body on the sheet metal, and (a) forming a concave portion on one surface side of the sheet metal and simultaneously forming a material of the sheet metal. A first clamping step in which the sheet metal is raised to the other surface side to form a convex portion on the other surface side, and (b) a bottom surface of the concave portion corresponding to the top surface while applying a pressing force to the top surface of the convex portion And a second pressing step of pressing the convex portion to form the convex portion into a cylindrical protrusion.

In the present invention, first, in the first pressing step, a concave portion is formed on one surface side of the sheet metal by plastic deformation by pressing the sheet metal between the upper die and the lower die. The sheet metal material is raised to the other surface side of the sheet metal, and a convex portion is formed on the other surface side. Next, in a second pinching step, the bottom surface of the concave portion corresponding to the top surface is pressed while applying a pressing force to the top surface of the convex portion by another upper mold and a lower mold, whereby the sheet metal material is pressed. A cylindrical projection is formed by integral molding. According to the present invention, particularly in the second pinching step, since the bottom surface of the concave portion is pressed while applying a pressing force to the top surface of the convex portion and the molecules of the sheet metal are fluidized, the height of the cylindrical protrusion is increased. Can be made about 5 to 9 times the sheet thickness, and shafts for various uses can be formed by sheet metal integral molding. According to this working method, it is also possible to instantaneously form and establish a plurality of (6 to 8) axes at a time. Thus, the cost can be significantly reduced as compared with the conventional method of planting the shafts one by one on the chassis.

In the present invention, it is preferable that in the first pressing step, the outer peripheral side of the concave portion formed on one surface side of the sheet metal is pressed with high pressure so that the sheet metal material easily flows to the convex portion. By doing so, when forming a convex portion on the other surface side of the sheet metal, material molecules of the sheet metal can be effectively flowed to the convex portion, and the convex portion can be formed more easily.

Next, a sheet metal working apparatus according to the present invention, to which the above-described sheet metal working method is specifically applied, presses the sheet metal between an upper mold and a lower mold to establish a cylindrical projecting body on the sheet metal. A machine tool comprising: (a) a male mold having a concave portion formed on one surface side of the sheet metal, and a concave portion having a smaller diameter than the male mold, the convex portion being formed on the other surface side of the sheet metal by the concave portion. A first tool comprising: a female mold to be formed; and a pressing tool slidably provided on an outer peripheral portion of the male mold and pressing one surface side of the sheet metal with high pressure during molding.
And (b) a convex male mold having an outer diameter smaller than that of the convex portion formed on the sheet metal by the first molding device, and a pressing force applied to the top surface of the convex portion when pressed by the convex male mold. A second molding device having a core press to be added is provided.

In this sheet metal working apparatus, it is preferable that the tip end surface of the convex male mold is inclined at a small angle from the peripheral edge toward the center so that the center is convex. In this case, the flow of the sheet metal material molecules can be made smoother, and the molding can be performed more easily.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of a sheet metal working method and a sheet metal working apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a view showing a processing procedure of a sheet metal working method according to one embodiment of the present invention, in which (a) is a cross-sectional view of a sheet metal to be processed (material sheet metal material), and (b) is a first view. FIG. 7C is a cross-sectional view illustrating the shape of the molded product after the completion of the pressing process, and FIG. 7C is a cross-sectional view illustrating the shape of the molded product after the completion of the second pressing process.

In this embodiment, a material having a uniform thickness t (generally 0.8 mm to 1.6 mm) is used as the sheet metal 1 to be processed as shown in FIG. From such a sheet metal 1 to be processed, first, in a first clamping step, a concave portion 2 is formed on one surface side, and at the same time, the material of the sheet metal 1 to be processed is raised on the other surface side and a convex portion 3 is formed on the other surface side. Is formed into an intermediate molded product 4 (see FIG. 1B). Next, in the second pinching step, the intermediate molded product 4
By pressing the bottom surface 2a of the concave portion 2 while applying a pressing force to the top surface 3a of the convex portion 3, a cylindrical protruding body 5 is established on the convex portion 3 and becomes a final molded product 6 (FIG. 1). (C)). In the case of a chassis such as a VTR, for example, the above-mentioned protruding bodies (shafts) 5 having different outer diameters and heights are 5
Approximately 8 are provided.

Next, from the sheet metal 1 to be processed to the final molded product 6
A molding step for molding the slab will be described with reference to FIGS.

First, a first forming apparatus 7 as shown in FIG. 2 is used to form an intermediate molded product 4 from a sheet metal 1 to be processed. The first molding device 7 includes a male mold (upper mold) 8 and a female mold (lower mold) 9, and the work piece 1 is interposed between the male mold 8 and the female mold 9. By pressing down the male mold 8 at an extremely high pressure, the workpiece 1 is plastically deformed by coining.

The contact surface of the male die 8 with the sheet metal 1 to be processed is formed flat, while the upper surface of the female die 9 is formed with a recess 9 a having a smaller diameter than the pressure receiving surface of the male die 8. . Also,
Pressing tool 1 slidable in the vertical direction on the lower outer peripheral surface of male mold 8
0 is fitted. The pressing tool 10 has a cross section V on the lower surface.
It has a U-shaped and annular sheet metal pressing portion 10a, and is constantly urged downward by the action of the compression coil spring 11.

With this configuration, the male mold 8 is held in a state in which the sheet metal 1 is interposed between the male mold 8 and the female mold 9.
As shown in FIG. 3, when the periphery of the formed portion of the sheet metal 1 is pressed with a strong spring force by the sheet metal pressing portion 10a, the sheet metal 1 9 is pressurized to an ultra-high pressure, the material of the sheet metal material of the concave portion 2 in FIG. 1B becomes the material of the convex portion 3, and the material molecules are plastically deformed. At this time, since the sheet metal pressing portion 10a sticks to the surface of the sheet metal 1 around the concave portion 2, the flow of the material molecules does not flow to the outer peripheral portion of the sheet metal 1 but flows to the convex portion 3 effectively. The molding of the molded article 4 is performed smoothly.

Here, the convex portion 3 of the formed intermediate molded product 4
Is preferably about 60% of the inner diameter B of the recess 2.
The height C of the projection 3 from the surface of the sheet metal 1 to be processed can be set to 80 to 130% of the sheet thickness t. FIG.
As shown in (b), after the formation of the intermediate molded product 4, the surface of the sheet metal 1 to be processed has a sheet metal pressing portion 10a.
A dent 12 is formed due to the bite of.

Next, from the intermediate molded product 4 to the final molded product 6
Is molded using a second molding device 13 as shown in FIG. The second molding device 13 includes a convex male mold 14 having an outer diameter smaller than the convex portion 3 of the intermediate molded product 4,
The top surface 3a of the convex portion 3 when pressed by the convex male mold 14
And a core presser 15 for applying a pressing force to the main body.

The tip surface 14a of the convex male mold 14 is inclined at a small angle from the peripheral edge toward the center so that the central portion becomes convex, so that the material molecules are directed outward during molding. It is designed to flow smoothly. The core presser die 15 is always pushed upward by a plurality of compression coil springs 16 having a strong spring force inserted downward.

With such a configuration, when a strong pressing force is applied to the top surface 3a of the convex portion 3 of the intermediate molded product 4 by the core pressing die 15 and the convex male die 14 is pressed down at an extremely high pressure,
As shown in FIG.
The raw material molecules flow so that a hole having an inner diameter D (see FIG. 1 (b)) is formed at the end, and a final molded product 6 as shown in FIG. 1 (c) is formed. Thus, the height H of the cylindrical protrusion 5 from the surface of the sheet metal 1 to be processed can be set to 3 to 9 times the plate thickness t. When the plate thickness t is 1.2 to 1.6 mm, the outer diameter A of the protrusion 5 is 4 to 8 mm, and the inner diameter D of the protrusion 5 is A-.
(0.4 to 0.7) mm.

In the molding by the second molding device 13, it is necessary to accurately control the pressing force applied to the core pressing die 15 to a constant value. Specifically, this pressing force is about 400 kg when the outer diameter of the protruding body 5 is 2 mm,
Approx. 500 kg at 3 mm, approx. 6 at 4 mm
The spring force of the compression coil spring 16 is set so as to be 00 kg.

According to the sheet metal working method of this embodiment, the sheet thickness t
Since a shaft 3 to 9 times as large as the above can be formed by sheet metal integral molding, low-cost production of a shafted chassis for precision equipment has become possible. That is, the conventional machined shaft is placed on the chassis
Since a plurality of shafts can be formed on the chassis at once with a press die as compared with the method of planting one by one, a significant cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a view showing a processing procedure of a sheet metal working method according to one embodiment of the present invention, wherein (a) is a cross-sectional view of a sheet metal to be processed (raw sheet metal material), and (b) is a sectional view; FIG. 4 is a cross-sectional view showing the shape of the molded product after the completion of the first pressing process, and FIG. 4C is a cross-sectional view showing the shape of the molded product after the completion of the second pressing process.

FIG. 2 is a cross-sectional view illustrating a first pinching step.

FIG. 3 is a cross-sectional view illustrating a first pinching step.

FIG. 4 is a sectional view illustrating a second pinching step.

FIG. 5 is a sectional view illustrating a second pinching step.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet metal to be processed 2 concave portion 2 a bottom surface 3 convex portion 3 a top surface 4 intermediate molded product 5 tubular protrusion 6 final molded product 7 first molding device 8 male mold (upper mold) 9 female mold (lower mold) DESCRIPTION OF SYMBOLS 10 Pressing tool 10a Sheet metal pressing part 11 Compression coil spring 12 Depression 13 Second forming device 14 Convex male die 15 Core pressing die 16 Compression coil spring

[Procedure amendment]

[Submission date] August 27, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (5)

[Claims] 1. A sheet metal working method for clamping a sheet metal between an upper mold and a lower mold to establish a cylindrical projecting body on the sheet metal.
(A) a first pressing step of forming a concave portion on one surface side of the sheet metal and simultaneously floating the material of the sheet metal on the other surface side of the sheet metal to form a convex portion on the other surface side; A second pressing step of pressing the bottom surface of the concave portion corresponding to the top surface while applying a pressing force to the top surface of the portion to form the convex portion into a cylindrical protrusion. Method. 2. The method according to claim 1, wherein in the first pinching step, an outer peripheral side of a concave portion formed on one surface side of the sheet metal is pressed with high pressure to make it easier for the sheet metal material to flow to the convex portion. The sheet metal working method described. 3. The sheet metal according to claim 1, wherein a height of the cylindrical protrusion from the other surface of the sheet metal is 3 to 9 times a thickness of the sheet metal. Sheet metal working method. 4. A sheet metal working apparatus which presses a sheet metal between an upper mold and a lower mold to establish a cylindrical projecting body on the sheet metal.
(A) a male mold having a concave portion on one surface side of the sheet metal, and a female mold having a concave portion having a smaller diameter than the male mold and forming a convex portion on the other surface side of the sheet metal by the concave portion; A first molding device having a pressing tool slidably provided on the outer peripheral portion of the male mold and pressing one surface side of the sheet metal with high pressure during molding; and (b) forming the sheet metal by the first molding device. A second male molding device having a convex male mold having an outer diameter smaller than that of the convex part, and a core pressing die for applying a pressing force to the top surface of the convex part when pressed by the convex male mold. Sheet metal working equipment. 5. The sheet metal according to claim 4, wherein the tip surface of the convex male mold is inclined by a small angle from the peripheral edge toward the center so that the center is convex. Machine tools.