JP2555665B2 - Counter hydraulic pressure drawing method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an opposed hydraulic drawing method and apparatus capable of simultaneously performing drawing and trimming.

(Prior Art) As a method of press-forming various metal panels from a single plate, there is a counter-hydraulic forming method that does not require female die processing. An apparatus for carrying out this method is described in Japanese Utility Model Publication Sho 62
No. 92020, Japanese Patent Application No. 61-298646, etc., for example, there is an opposed hydraulic forming device shown in FIG.
In the figure, reference numeral 1 denotes a male die (hereinafter referred to as a punch) having a pressing surface formed in a product shape, which is attached to an inner table 2 and is vertically movable in an outer table 3. Below the punch 1, a hydraulic dome 5 filled with a liquid 4 such as water is placed on the bolster table 6 so as to face the punch 1. Then, the work (product material) W is sandwiched between the upper blank holder 7 and the lower blank holder 8. Furthermore, the product shown in Fig. 4 (door outer panel)
Difficult to form a sharp shape when molding W1 A,
The local female mold 9 is erected on the lower mold 10 of the bottom surface in the liquid facing the B part (recessed R part). 11 is a die plate on which the lower mold 10 is mounted, 1
2 is a cushion pin and 13 is an O-ring. The opposed hydraulic forming device configured as described above operates as follows.

When the work W is clamped by the upper and lower blank holders (7, 8) and the punch 1 is pushed into the hydraulic dome 5 filled with water,
W is brought into close contact with the punch 1 by the liquid pressure generated by the pushing of the punch 1 to form the product shape. In the A and B parts, the shape is surely formed by the local female die 9.

When the liquid pressure is insufficient, a pump (not shown) is used to inject water from the inlet 14 to forcibly increase the liquid pressure and bring the punch 1 into close contact with the pressing surface.

And this molded product is processed in a separate process according to various production conditions.
Trimming was performed by punching, plasma, laser, etc., and flanging, etc. was also performed by a bending die or jig to obtain a finished product.

(Problems to be solved by the invention) Actually, in order to commercialize the product, after molding by the above-mentioned molding method, the peripheral surface is trimmed in the next step.

Therefore, since a drawing tool and a trimming tool are separately required, not only the equipment cost is increased, but also the processing cycle time of the molding is long and it is necessary to move the press work between steps. The work was complicated and it was difficult to increase productivity.

The present invention provides a counter hydraulic drawing method and an apparatus thereof, in which trimming can be performed at the same time when a work is drawn so that the drawing and trimming of the work can be performed by one device. With the goal.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a hydraulic dome 28.
In the counter-hydraulic forming method in which the punch W is lowered into the punch W to press the work W against the punch pressing surface 21 by hydraulic pressure, a final hydraulic pressure is applied to the hydraulic dome 28 to press the work W by punching. It is characterized in that the edge of the molded product of the work W is trimmed almost at the same time as the complete contact with the surface 21. Further, the apparatus for carrying out this method is provided with a cutting edge receiving portion 23 on the side edge portion of the punch 20, and cooperates with the cutting edge receiving portion in the hydraulic dome 28 to form a molded product of the work W. It is characterized in that a cutting blade 33 for trimming the edge is provided upright.

(Operation) When the device for performing the above method is operated,
The punch 20 pushes the work W into the hydraulic dome 28, and the work W is gradually pressed against the pressing surface 21 of the punch 20 by the hydraulic pressure, and the end of the work W is pinched by the cutting edge receiving portion 23 and the cutting edge 33 at the end of the forming. When the work W is formed in close contact with the shape of the pressing surface 21, the edge of the work W is cut out by the cutting blade 33 and trimmed.

(Example) An example of the present invention will be described with reference to FIG.

 FIG. 1 is an apparatus for carrying out the method of the present invention.

In the figure, 20 is a punch (male type) and the pressing surface at the tip
21 is machined into a product shape and both sides are cut at right angles.
And the cutting edge receiving portion 23 is provided on the right-angled convex portion. A spacer 24 lower than the position of the cutting edge receiving portion 23 and a punch block 25 with rounded corners are attached to this step portion 22 with the spacer 24 interposed, and the amount of protrusion of the end of the pressing surface can be adjusted during molding. The work W does not come into contact with the cutting edge receiving portion 23. In addition, the punch 20 is an inner table 26
And is mounted so as to be movable up and down in the outer table 27.

A hydraulic dome 28 is located below the punch 20 and is filled with a liquid (for example, water containing an anticorrosive agent) 29. The lower die 31 on the die plate 30 in the liquid is placed on both sides of the pressing surface 21. An elastic body 32 is erected below the cutting portion, and a cutting blade 33 is erected below the cutting blade receiving portion 23. Further, depending on the shape of the pressing surface 21, the local female mold 34
Is provided. Then, at each height position, the height of the cutting edge is set so that the side portion of the work W is cut out when the work W (pressing surface) is molded, and the elastic body 32 is positioned before the cutting edge 33. It abuts the work, elastically deforms and urges upward.

Further, an upper blank holder 35 is provided on the lower end of the outer table 27, and a lower blank holder is provided on the upper peripheral edge of the hydraulic dome 28.
36 is provided, and the work W is clamped by these two members. 34 is a sealing material.

When the work W is sandwiched between the upper blank holder 35 and the lower blank holder 36 and the punch 20 is lowered, the work W is immersed in the liquid 29 while being acted on the pressing surface 21. The work W is further pressure-bonded to the pressing surface by the hydraulic pressure generated at this time, and is molded while controlling the pressure appropriately. The elastic body 32 contacts the work W before the work W comes into close contact with the pressing surface (FIG. 2). Then, the hydraulic pressure is increased to bring the work W into close contact, and the edge is trimmed by the cutting blade 33. By applying the final pressure at this time, the opposing work portions of the cutting edge receiving portion 23 of the punch 20 project toward the cutting edge receiving portion 23 side against the pressing of the punch block 25, and adhere to the surface thereof. Then, almost simultaneously with this contact, the cutting edge 33 acts on the work W and cooperates with the cutting edge receiving portion 23 to cut out the edge. Then
A work, that is, scrap, outside the cut portion is instantaneously pressed against the punch block 25, and a gap is formed between the work and the end portion of the work as a product (FIG. 3).

After that, when the punch 20 is pulled upward, the formed work can be removed from the cutting blade 33 by the upward force of the elastic body 32 without being caught by the end of the scrap.
After that, the upper blang holder 35 is pulled up, and the lower die is raised to lift the formed work W to a predetermined height.

The elastic body 32 may be a spring, a cylinder, etc.
When the force for pressing the work W against the pressing surface is weak, a method of slightly increasing the hydraulic pressure from the beginning may be used.

(Effects of the Invention) The present invention is one in which the above method is carried out by the present apparatus.
The edges can be surely trimmed at the point when drawing is completed by the counter-hydraulic molding, the mold tool for trimming is not required, the equipment cost is reduced by about 1/3 of the conventional one, and the equipment can be Since the process can be divided, the trimming time is shortened, and the work transfer between processes is also reduced, improving the machining efficiency,
Labor costs for operating the equipment can also be reduced. In addition, a clean cut surface can be obtained as compared with the conventional punching process, which ensures more reliable separation of the product work and scrap, and eliminates the need for manual scrap division.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold part of an opposed hydraulic drawing device according to the present invention, FIGS. 2 and 3 are cross-sectional views of a main part when the punch position of FIG. 1 is moved, and FIG. Is a perspective view of a product obtained by molding a work, and FIG. 5 is a cross-sectional view of a conventional opposed hydraulic molding apparatus. 20 …… Punch, 21 …… Pressing surface, 23 …… Cutting edge receiving part 28 …… Hydraulic dome, 31 …… Lower mold, 33 …… Cutting edge W …… Workpiece

Claims (2)

(57) [Claims] 1. A counter-hydraulic molding method in which a work is pushed by a punch into a hydraulic dome filled with a liquid, and the work is hydraulically brought into close contact with a punch pressing surface to form the work.
A counter hydraulic squeezing method, characterized in that the final hydraulic pressure is applied to the hydraulic dome to bring the work into close contact with the punch pressing surface, and at the same time, the edge of the molded product of the work is trimmed. 2. A hydraulic dome filled with a liquid, and a punch capable of moving up and down in the hydraulic dome, the work is pushed by the punch into the hydraulic dome, and the work is brought into close contact with the punch pressing surface by the hydraulic pressure. In the opposed hydraulic forming device, a cutting edge receiving portion is provided on a side edge portion of the punch, and a cutting blade that cooperates with the cutting edge receiving portion to trim the edge of the work is provided upright in the hydraulic dome. A counter hydraulic drawing device.