JPH03258415A - Drawing die - Google Patents

Abstract

PURPOSE:To reduce the cost of equipment and to allow the improvement of productivity by arranging the divided die retractabily, arranging the lever in freely moving on the lower die and setting the 1st pin whose upper end can be brought in contact with the upper die and the 2nd pin whose upper end can be brought in contact with the divided die on the both end parts of the lever. CONSTITUTION:The forming surface 2a for general shape forming and the forming surface 2b for projecting surface forming are made on the upper die 2. The forming surface 3a for general shape forming is made on the lower die 3. The forming surface 4a for projecting part forming is made on the divided die 4. The divided die 4 is arranged at the forming surface 3a of the lower die 3 in freely retractable. The transverse lever 8 is arranged at the lower die in freely moving. The 1st pin 13 whose upper end can contact with the upper die 2 and the 2nd pin 20 whose upper end can contact with the divided die 4 are arranged at both end parts of the lever 8. Therefore, the generation of wrinkles at the foot of projecting parts can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a draw mold for forming a general shape part having a large curved surface and a protrusion within the general shape part from a single blank material in one step.

(Prior art) Press forming of automobile bonnets, etc., especially draw forming, involves clamping the periphery of a blank material with an upper mold and a blank holder, and then forming the desired shape by lowering the upper mold further. .

(Problem to be Solved by the Invention) However, when an attempt is made to not only mold a general shape part having a large curved surface but also to mold a protrusion inside this general shape part by the above-mentioned draw molding, the upper mold descends and first Since the uppermost protrusion is embossed, wrinkles are generated at the bottom of the protrusion due to this local narrowing.

(Means for Solving the Problems) In order to solve the above problems, the present invention has an upper die having one side for shaping the general shape part and the protrusion, and one side for shaping the general shape part. It is equipped with a lower mold and a split mold having one side for shaping the protrusion, and the split mold is disposed so as to be freely retractable from the molding surface of the lower mold. It is movably arranged, and a first pin whose upper end can come into contact with the upper mold and a second pin whose upper end can come into contact with the split mold are provided at both ends of this horizontal rod.

(Function) The upper mold descends and shapes the general shape part between it and the lower mold,
When the upper mold further descends to near the bottom dead center, the first pin is pushed down, one end of the horizontal rod descends, the horizontal rod swings, and the other end of the horizontal rod rises, causing the second pin to move. By rising, the split metal mold rises and protrudes from the molding surface of the lower die, and the rising split metal mold and the upper mold that descends relative to each other cooperate to form the protruding portion.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figure 1 is an overall sectional view of the draw mold according to the present invention, Figure 2 is a front view of the main parts of the draw mold, Figure 3 is an enlarged view of the main parts of the draw mold, and Figure 4 is molding using the draw mold. FIG. 5 is a cross-sectional view showing the process, and a perspective view showing a workpiece formed by the same draw die.

The draw die l has a forming surface 2a for forming a general shape part in the center, a forming surface 2b for forming a protrusion, and one side on which a protrusion 2C for clamping the blank is formed on the periphery. An upper mold 2 that can be raised and lowered freely, a lower mold 3 disposed opposite to the upper mold 2 and having one side forming a molding surface 3a for shaping a general shape part, and a molding for shaping a protrusion. A split mold 4 having one side forming a surface 4a is provided, and the split mold 4 is disposed so as to be freely protrusive and retractable from the molding surface 3a of the lower mold 3. Furthermore, a blank holder 5 is provided around the four circumferences of the lower die 3, and a groove 5a that fits into the protrusion 2c of the upper die 2 is formed in the blank holder 5.

A box portion 6 is provided on the abbreviated portion 3b of the lower die 3, a support shaft 7 made of a round bar or the like is rotatably provided at the front end of the box portion 6, and a horizontal rod 8 is mounted on the support shaft 7. It is mounted so that it can swing freely.

A contact portion 12 is connected to one end of the horizontal rod 8 via a rotating shaft 11.
is integrally provided, and a first pin 13 whose upper end can come into contact with the contact plate 2d of the upper die 2 is suspended in the blank holder 5 by a pin 5b above the contact part 12. The lower end of the pin 13 is brought into contact with the contact portion 12 so as to be able to come into contact with and separate from it.

Also, a contact portion 1 is connected to the other end of the horizontal rod 8 via a rotating shaft 15.
6 are integrally provided with locking devices 18 and 19 attached with bolts 17, and a second pin 20 is interposed between this contact portion 16 and the split mold 4. As shown in FIG. 2, this second pin 20 has flanges 20a on both sides of its lower end, is biased downward by a spring 21 interposed between it and the inner surface of the box part 6, and is pushed along the slide base 22. It can be raised and lowered freely.

The operation of forming a bonnet using the draw die configured as described above will be explained below.

First, a blank B is inserted between the upper die 2 and the lower die 3 by a work setting device (not shown), and when the insertion of the blank B is completed, the upper die 2 is lowered as shown in Fig. 4 (A, ). Then, the peripheral edge of the blank B is held between the protrusion 2d of the upper die 2 and the groove 5a of the blank holder 5. At this time, the blank holder 5 is urged upward by a cushion pin (not shown) of the press.

In this state, the upper die 2 is further lowered, and as shown in FIG. 2B, the general shape portion 26 of the bonnet 25, which is the product portion, is generally shaped between it and the lower die 3. At this time, the split mold 4 is recessed from the molding surface 3a of the lower mold 3.

Then, when the upper die 2 further descends and reaches close to the bottom dead center, the first pin 13 abuts against the contact portion 12 and pushes it down, so that the horizontal rod 8 swings around the support shaft 7. At this time, the abutting surfaces of the abutting part 12 and the first pin 13 and the abutting surfaces of the abutting part 16 and the second pin 20 each slide against each other, and the downward stress is reliably converted into rotational force and the lever is In principle, it is converted into an upward stress.

This swinging of the horizontal rod 8 causes the second pin 20 to move against the spring 2.
The molding surface 2 of the upper mold 2 is pushed up against the urging force of the upper mold 2, and as shown in FIG.
b, to form the protrusion 27 within the general shape portion 2e of the bonnet 25.

After the molding is completed in this way, the upper mold 2 rises, and the split mold 4 sinks into the molding surface 3a of the lower mold 3 by the restoring force of the spring 21.

(Effects) As explained above, according to the present invention, an upper mold having one side for shaping the general shape part and the protrusion, a lower mold having one side for shaping the general shape part, A split mold having one side for shaping the protrusion is provided, and this split mold is made to protrude from the molding surface of the lower mold by utilizing the lowering of the upper mold, so that the general shape part and the protrusion can be shaped. It is possible to mold a product with a single process in one step, reducing equipment costs and improving productivity.Also, after the general shape part has been molded just before the bottom dead center of the upper mold, the split mold rises and the protruding part Since the molding of the protrusion starts, it is possible to prevent wrinkles from forming at the hem of the protrusion with a simple configuration.

[Brief explanation of drawings]

Figure 1 is an overall sectional view of the draw mold according to the present invention, Figure 2 is a front view of the main parts of the draw mold, Figure 3 is an enlarged view of the main parts of the draw mold, and Figure 4 is molding using the draw mold. FIG. 5 is a cross-sectional view showing the process, and a perspective view showing a workpiece formed by the same draw mold. In the drawings, 1 is a draw mold, 2 is an upper mold, 3 is a lower mold, 4 is a split mold, 8 is a horizontal rod, 13 is a first pin, and 20 is a second pin. Special representative applicant

Claims (1)

[Claims] In a draw mold for forming a general shape part having a large curved surface and a protrusion within this general shape part from one sheet of blank material in one step, a top having one side for shaping the general shape part and the projection part. A mold, a lower mold having one side for shaping the general shape part, and a split mold having one side for shaping the protrusion, the split mold having a molding surface of the lower mold. Further, a horizontal rod is swingably arranged on the lower mold, and at both ends of the horizontal rod, a first pin whose upper end can come into contact with the upper mold and the split mold are provided. A draw type characterized in that it is provided with a second pin that can come into contact with the.