JPH0323019A - Die structure of opposed hydraulic forming device - Google Patents

Abstract

PURPOSE:To generate a force to press a die plate to a room forming member, to improve the sealing properties and to prevent the upward deformation of the die plate by arranging sealant between the die plate and the room forming member nearer to the central side of the hydraulic room than the forming profile of a forming opening part. CONSTITUTION:A blank is mounted on the die plate 2 so that the hydraulic room 4 is clogged and as the external circumferential part of the blank is clamped by a push plate, the punch is lowered so that it advances from the upper part to the hydraulic room 4. The blank is bent by the forming profile 7 at the top end of the forming opening part 1 of the die plate 2 and while the surface of a punch is covered with the blank, the blank plunges into the hydraulic room 4, receives opposed liquid pressure, sticks to the surface of the punch and is drawn in a prescribed shape. In this time, the internal circumferential surface of the forming opening part 1 of the die plate 2 takes a downward drawing shape, the sealant S1 between the die plate and a room forming member 5 is positioned nearer to the side of the center IC of the hydraulic room than the forming profile 7, pressure to the die plate is higher than the bearing on a joint surface A1 and sealing action is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a die structure of an opposed hydraulic forming apparatus for forming automobile parts, electrical parts, etc. by drawing a blank material such as a thin plate.

(Prior Art) As a conventional opposed hydraulic molding apparatus of this type, there is one shown in FIG.

This device comprises a die plate l2 having a forming opening 11;
A chamber forming member 15 defining a hydraulic pressure chamber l4 is interposed between the bottom plate 13 and the bottom plate 13, and these members 12. 13.
Sealing materials St and S2 surrounding the hydraulic pressure chamber l4 are provided between the holes 15 and 15 to protect the die structure.

Then, a blank material 18 is placed on the die plate 12 so as to close the hydraulic chamber 14, and the outer periphery of this blank material 18 is sandwiched between the presser plates 19 that descend in opposition to the die plate 12. Insert the punch 20 into the hydraulic chamber 1 from above.
4, the blank material 18 is drawn into a predetermined shape by the pressing force of the bunch 20 and the hydraulic pressure in the hydraulic pressure chamber 14. (Problems to be Solved by the Invention) In the conventional device, the molding opening 11 of the die plate 12
The molding contour 17 at the upper end and the lower end have the same area and are parallel to the hydraulic pressure chamber center CL, that is, form a straight inner peripheral surface, and the sealing material S1 between the die plate 12 and the chamber-shaped control member 15 is located outside the forming contour 17, so when opposing hydraulic pressure is generated in the hydraulic pressure chamber, hydraulic pressure acts on the lower surface of the die plate 12, generating hydraulic pressure that presses the die plate l2 upward, and the joining surface The opening may become too loose, which may impair the sealing performance of the sealing material S1, or the die plate 12 may deform upward, changing the condition of the die plate, which may impair moldability.

Also, each part! 2, 13. 15 sealing material Sl,
The sealing position by S2 is equidistant from the center CL and the inner peripheral surface of the hydraulic pressure chamber 14, and the areas of the joint surfaces AI and A2 are approximately the same, so the same hydraulic pressure acts on those joint surfaces. If the downward force of the die plate 12 is small, an upward force will also be generated on the chamber-shaped hollow member 15 due to the lack of restraint from above, and the sealing performance of the lower sealing material s2 may deteriorate. By the way, as a means of applying downward force to the die plate 12, a method of fastening the die plate 12, the chamber forming member 15, and the bottom plate 13 with bolts is adopted, but the bolts are subjected to repeated stress and elongate. When bolts are used, their elongation is large, so the holding effect of the die plate is reduced.

The first object of the present invention is to form the molding opening of the die plate into a constricted shape toward the chamber forming member, and to place the sealing material between the molding opening and the chamber forming member closer to the center of the hydraulic chamber than the molding contour at the upper end of the molding opening. It is an object of the present invention to provide a die structure for a facing hydraulic forming device in which a pressing force is generated on a die plate toward a chamber-shaped control member using facing hydraulic pressure. A second object of the present invention is to arrange the sealing material provided between the die plate, the chamber forming member, and the bottom plate so that the area of the joint surface surrounded by the bottom plate is smaller than that of the die plate, It is an object of the present invention to provide a die structure for an opposed hydraulic molding device in which a chamber forming member generates a pressing force toward a bottom plate.

(Means for solving the problem) The first specific means for solving the problem in the present invention is as follows:
A facing hydraulic forming apparatus in which a chamber forming member for forming a hydraulic chamber is interposed between a die plate having a forming opening and a bottom plate, and a sealing material surrounding the hydraulic chamber is provided between these members. In the die structure, the inner circumferential surface of the molding opening of the die plate is drawn toward the chamber forming member, and the sealing material between the die plate and the chamber forming member is placed closer to the center of the hydraulic pressure chamber than the molding contour of the molding opening. It was placed in

A second specific means is to interpose a chamber forming member that forms a hydraulic chamber between a die plate having a molding opening and a bottom plate, and a seal that surrounds a hydraulic chamber between these members. In the die structure of the opposed hydraulic forming apparatus, each sealing material is placed at a position closer to the center of the hydraulic chamber so that the sealing material on the bottom plate side surrounds a smaller joint surface area than the sealing material on the die plate side. It is placed in

(Function) In Fig. 1, a blank material is placed on the die plate 2 so as to close the hydraulic chamber 4, the outer periphery of this blank material is sandwiched between the presser plates, and in this state, the punch is applied from above with the liquid. It is lowered so as to enter the pressure chamber 4.

The blank material is bent at the forming contour 7 at the upper end of the forming opening 1 of the die plate 2, rushes into the hydraulic pressure chamber 4 while covering the punch surface, receives the opposing hydraulic pressure, and adheres tightly to the punch surface to a predetermined position. It is drawn into a shape.

At this time, the inner circumferential surface of the molding opening 1 of the die plate 2 has a downward drawing shape, and the sealing material S1 between it and the chamber-shaped restraining member 5 is located closer to the hydraulic pressure chamber center CL than the molding contour 7. Because of this position, the pressure pressing the die plate 2 downward is higher than the surface pressure at the joint surface A1, and the sealing action by the sealing material S1 is ensured, and the die plate 2 is pressed against the chamber forming member 5.
is backed up by , and the downward deformation is suppressed.

Further, regarding the chamber forming member 5, the area of the joint surface A2 surrounded by the seal material S2 between the bottom plate 3 and the bottom plate 3 is larger than the area of the joint surface A1 surrounded by the seal material S1 between the die plate 2 and the bottom plate 3. are the same or smaller, the chamber-shaped member 5
A force is generated that presses the die plate 3 against the bottom plate 3, and the sealing action by the sealing material S2 is ensured, and no force is generated that pushes the die plate 2 up. (Example) Hereinafter, an example of the present invention will be described based on the drawings.

In the first embodiment shown in FIG. 1, a chamber forming member 5 forming a hydraulic pressure chamber 4 is interposed between a die plate 2 having a molding opening 1 and a flat bottom plate 3. The three members 2, 3, and 5 are fastened together with a plurality of bolts 6.

The chamber forming member 5 is formed of one chamber 5a, and a groove is formed on the surface that joins the die plate 2 and the bottom plate 3 so as to surround the hydraulic chamber 4, and a seal such as an O-ring is formed on the surface that joins the die plate 2 and the bottom plate 3. Materials Sl and S2 are inserted, and each member 2,
3. The joint surface between the two parts is sealed. The upper end of the forming opening 1 of the die plate 2 is a forming contour 7 that forms the outline of the drawn product, and the forming opening 1 communicates with the hydraulic chamber 4 and constitutes a part thereof. ,
Its inner circumferential surface is tapered to the end, and has a drawn shape with a smaller area on the chamber forming member 5 side than the molding contour 7.

The upper sealing material S1 is located at approximately the same distance from the inner circumferential surface of the hydraulic chamber 4 all around the circumference, and is located closer to the center CL of the hydraulic chamber 4 than the molded contour 7 of the molded opening 1.

The lower sealing material S2 is also located at approximately the same distance from the inner peripheral surface of the hydraulic pressure chamber 4 all around the circumference, and is located closer to the center CL of the hydraulic pressure chamber than the upper sealing material S1. The size of the hydraulic chamber 4 is the same from the upper end to the lower end, and its inner circumferential surface is parallel to the hydraulic chamber center CL. Therefore, the joint surface A1 surrounded by the upper sealing material S1 is Surrounding joint surface A
When the area becomes larger than 2 and opposing hydraulic pressure is applied to the hydraulic pressure chamber 4,
A pushing force acts from the top to the bottom.

In the second embodiment shown in FIG. 2, the inner circumferential surface of the hydraulic pressure chamber 4 is tapered downward, and even if the intervals between the upper and lower sealing materials Sl, S2 and the inner circumferential surface of the hydraulic chamber 4 are equal, , the area of the joint surface A2 surrounded by the lower seal material S2 is smaller than the area of the joint surface ^l surrounded by the upper seal material S1. As a result, only a force that presses the chamber-shaped restraining member 5 downward, that is, toward the bottom plate 3 is generated.

Note that most of the molded products have a tapered tip, and the punch usually has a shape that tapers downward, so even if the hydraulic chamber 4 is narrowed downward, there is no problem with molding. The die plate 2 is the same as that of the first embodiment. In the third embodiment shown in FIG. 3, the chamber-shaped control member 5 is formed of a chamber 5a and an inserter 5b fitted into the inner circumferential side of the chamber 5a. A chamber 4 is formed, an upper sealing material S3 is provided on the upper surface thereof, and a lower sealing material S4 is provided on the lower surface thereof, the area of the surrounding joining surface A2 is smaller than the area of the surrounding joining surface A1 of the upper sealing material S3.

Note that the inner peripheral surface of the chamber 5a is parallel to the center CL of the hydraulic pressure chamber,
The areas of the surrounding joint surfaces of the upper and lower sealing materials Sl and S2 are the same, but the inner peripheral surface of the chamber is made parallel to the inner peripheral surface of the insert 5b, and the surrounding joint surface area of the lower sealing material S2 is made equal to that of the upper sealing material S1. You can make it smaller than . Die plate 2
is the same as that of the first embodiment. In the fourth embodiment shown in FIG. 4, the chamber forming member 5 and the die plate 2 are fixed with upper bolts 6a, and the chamber forming member 5 and the bottom plate 3 are fixed with lower bolts 6b. By fastening 2.3.5 in two parts at a time, it is possible to use short bolts and the elongation of the bolts due to repeated loads is reduced. Although the die plate 2 and the chamber forming member 5 are those of the second embodiment, they may be those of the first or third embodiment. In the fifth embodiment shown in FIG. 5, the die plate 2 is similar to the prior art in which the molding opening l has an inner circumferential surface parallel to the hydraulic pressure chamber center CL, and the chamber forming member 5 has an inner circumferential surface. has a larger Taber angle than the second to fourth embodiments, and the downwardly tapered shape is noticeable. Although the lower sealing material S2 is farther from the hydraulic chamber 4 than the upper sealing material S1, the area of the joint surface A2 that it surrounds is smaller than the area of the surrounding joint surface A1 of the upper sealing material S1. The pressure presses the chamber forming member 5 toward the bottom plate 3 side.

Although the pressing force on the chamber-shaped restraining member side due to the opposing hydraulic pressure does not act on the die plate 2, by using a short upper bolt 6a, the fastening force can be maintained for a long period of time, and the die plate 2 and the chamber are The sealing effect between the forming members 5 is maintained. That is, a force in the -L direction is generated on the die plate 2, but
After making sure that the force acting on the chamber-shaped member 5 is directed downward and that the total force acting on both of them is directed downward, use short bolts with a small amount of elongation to fasten the die plate 2. By suppressing the upward force of the die plate 2, the opening at the joint surface A1 becomes smaller, and the sealing effect can be improved. The sixth embodiment shown in FIG. 6 uses the die plate 2 of the fifth embodiment and the chamber forming member 5 of the third embodiment. The fastening means fastens the die plate 2 and the insert 5b with an upper bolt 6a, and the chamber 5a and the bottom plate 3 with a lower bolt 6b. The upper bolt 6a is shorter than those in the fourth and fifth embodiments. In the case of this sixth embodiment, the above-mentioned bolts}6a. In addition to 6b, die plate 2 and chamber 5
Bolts that fasten the parts 2.3.5 together with bolts 2.3.5 are also used. The seventh embodiment shown in FIG. 7 is a chamber forming member 5 of the fourth embodiment.
is formed by two upper and lower chambers 5a+ + 5a, and the sealing material S1 located between the die plate 2 and the upper chamber 5a+ is located closer to the hydraulic pressure chamber center CL than the molding contour 7, and the upper and lower chambers Seal material S between 5a++ and 5a2
5 has a smaller surrounding bonding surface area than the sealing material S1,
The sealing material S2 located between the lower chamber 5ax and the bottom plate 3 is set to have a smaller surrounding bonding surface area than the sealing material S5, and is
It is arranged so that a downward force due to the opposing hydraulic pressure acts on all of a+ and 5az, and on top of that, 6a and 6b
is shortened. It should be noted that making the chamber-shaped member 5 multi-layered vertically can be applied to the first to sixth embodiments, and the number of layers may be three or more. The present invention is not limited to the above embodiments, and can be modified in various ways. For example, the inserter 5b of the third embodiment and the die plate 2 may be additionally fastened with short bolts, or the lower bolts 1-6b of the seventh embodiment may be used to connect the upper and lower chambers 5.
a+. 5ag and the bottom plate 3. (Effects of the Invention) According to the present invention described in detail above, the inner circumferential surface of the molding opening of the die plate is shaped to draw toward the chamber-forming member, and the sealing material between the die plate and the chamber-forming member is molded. Since it is located closer to the center of the hydraulic chamber than the molding contour of the opening, the opposing hydraulic pressure during drawing forming can generate a force that presses the die plate toward the chamber forming member, improving sealing performance and sealing the die. Upward deformation of the plate can be prevented.

In addition, each sealing material is placed close to the center of the hydraulic chamber so that the sealing material on the bottom plate side has a smaller surrounding joint surface area than the sealing material on the die plate side. As a result, the surface pressure on the joint surface on the bottom plate side of the chamber forming member is lower than that on the joint surface on the die plate side, and the chamber forming member receives a force that is pressed against the bottom plate side, thereby improving the sealing performance between the chamber forming member and the bottom plate. Upward deformation can also be prevented.

[Brief explanation of drawings]

Figures 1 to 7 are cross-sectional views showing the first to seventh embodiments of the present invention, and Figure 8 is a cross-sectional view of a conventional device, showing each half of the device with different phases when the punch is raised and lowered. It is. 1. Molding opening, 2. Die plate, 3.. Bottom plate, 4. Hydraulic pressure chamber, 5. Chamber shaped control member, 5a.
-...-Chamber, 5b-1 insert, 6-bolt, 7-molded contour, s-sealing material, A-1 joint surface,
CL: Center of one hydraulic pressure chamber.

Claims (2)

[Claims] (1) A chamber forming member forming a hydraulic chamber is interposed between a die plate having a molding opening and a bottom plate,
In the die structure of the opposed hydraulic forming apparatus in which a sealing material surrounding the hydraulic chamber is provided between these members, the inner circumferential surface of the molding opening of the die plate is drawn toward the chamber forming member, and the die plate and A die structure for an opposed hydraulic molding device, characterized in that a sealing material between the chamber forming member and the molding opening is placed closer to the center of the hydraulic chamber than the molding contour of the molding opening. (2) A chamber forming member forming a hydraulic chamber is interposed between the die plate having the molding opening and the bottom plate,
In the die structure of the opposed hydraulic forming apparatus in which a sealing material surrounding the hydraulic chamber is provided between these members, each of the sealing materials has a joint surface area that is larger than the sealing material on the bottom plate side surrounding the sealing material on the die plate side. A die structure of an opposed hydraulic molding device characterized by being arranged close to the center of the hydraulic chamber in order to reduce the size of the die.