JPH04253530A - Production of drawing die - Google Patents

Abstract

PURPOSE:To exactly correct the shape of a die and a punch of the reference side by inserting interposing materials to be plastically deformed between the die and the punch, parting the die and the punch after fitting and measuring clearances from the thicknesses of the interposing materials. CONSTITUTION:The die 5 is formed to comply approximately with the outer side shape of a semi-finished product so as to fit the punch 3 and the die 5 is used as the reference side. The die 5 and the punch 3 as well as a blank holder 4 are set to a ram 6 and bolster 7 of a press machine. A proper number of the interposing materials 8 which are small pieces of plastically deformable soft metals, such as lead, are inserted between the die 5 and the punch 3 and after the die 5 and the punch 3 are mated in relative positions, the die and the punch are parted. The thicknesses of the respective interposing materials 8 crushed by the die 5 and the punch 3 are measured and the clearances between the respective parts of the die 5 and the punch 3 are measured. The shape of the die 5 on the reference side is so corrected and set in shape as to provide the prescribed clearance corresponding to the thickness of a work in accordance with the results thereof, by which the drawing die is obtd.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a manufacturing method suitable for manufacturing a drawing die for drawing a plate-shaped workpiece by the cooperation of a die and a punch that fit into each other with a predetermined clearance. It is something.

0002

2. Description of the Related Art When manufacturing an automobile body rear side panel 1 as a product, for example, as shown in FIG. 4, from a plate-shaped work, the rear fender portion 1a has a bowl-like cross-sectional shape as shown in FIG. 5, unlike other parts. Since the semi-finished product 2 of the rear side panel is formed by drawing a plate-shaped workpiece in order to perform smooth drawing forming, the semi-finished product 2 of the rear side panel is formed, and the cross-sectional shape of the portion corresponding to the rear fender portion 1a is shown in FIG. The semi-finished product 2 is cut into a bowl shape as shown in FIG.
After that, the part 2a that will become the rear fender part 1a is bent at the edge as shown by the imaginary line in FIG. 6 to complete the rear fender part 1a.

[0003] Conventionally, when manufacturing a drawing die for forming the semi-finished product 2, as shown in FIG.
First, the punch 3 is formed to accurately follow the shape of the inside of the semi-finished product 2, and then a blank holder 4 that can be raised and lowered is formed on the outside of the punch 3, and the punch 3 and blank holder 4 are connected to the reference side. At the same time, a die 5 is formed to roughly follow the outer shape of the semi-finished product 2 so as to fit into the punch 3, and the die 5 is set as the reference side, and then the die 5, the punch 3 and The blank holder 4 is set on the ascending and descending ram 6 of the press machine and the fixed bolster 7, and a small piece of soft metal such as lead that deforms plastically is inserted between the die 5 and each part of the punch 3. An appropriate number of inserts 8 are inserted, and the die 5 and punch 3 are once aligned at a predetermined relative position as the ram 6 moves up and down, and then separated. By measuring the thickness of the insert 8, the clearance between each part of the die 5 and the punch 3 is measured, and then,
Based on the measurement results, a method has been adopted in which the shape of the die 5, which is the reference side, is corrected and matched so that a predetermined clearance corresponding to the thickness of the plate-shaped workpiece is left.

0004

[Problems to be Solved by the Invention] However, when manufacturing a drawing die as described above, generally, the position 5a of the die 5 and the punch 3 where the extra thickness 2b is formed from the plate-shaped workpiece,
3a, in order to allow the material to move smoothly to the part 2a that will become the rear fender part 1a, those walls are curved with a large radius, and the clearance between the walls at those positions is adjusted to allow the material to move smoothly to the part 2a that will become the rear fender part 1a. Position 5 forming part 2a
It is necessary to make the distance between the walls at positions 5b and 3b larger than that between the walls.For this reason, when manufacturing using the conventional method described above, at the positions 5b and 3b, the approximate extension in the downward direction of the die 5 occurs during the mold matching. The vertical walls of the die 5 and the punch 3 are the insert material 8.
On the other hand, at the positions 5a and 3a where the extra thickness 2b is formed, the walls of the die 5 and punch 3 receive the thrust force F1 from the insert 8.
The horizontal thrust force F is not large enough to counteract the
2, the die 5 escapes to the side of the position 5b that forms the part 2a that will become the rear fender part 1a, and the clearance near that position 5b is measured to be larger than the actual one, and the exact shape of the die 5 is incorrect. There was a problem that alignment became difficult.

[0005]

[Means for Solving the Problems] An object of the present invention is to provide a method for manufacturing a die that advantageously solves the above-mentioned problems. When manufacturing a drawing die that performs drawing on a plate-shaped workpiece by working together with a die and a punch that fit into each other with a gap in between, the die and punch are placed at the position where excess metal is to be formed from the workpiece. and a punch, each of which has a reference surface extending in the direction in which the die and the punch approach each other, and is plastically deformed between the reference surfaces of the die and the punch and between a position where a product is formed from the workpiece. The clearance between the positions of the die and punch where a product is formed from the workpiece is measured by inserting the die and punch, fitting the die and punch together, and then separating them and measuring the thickness of the insert. Based on the measurement results, the shapes of the die and punch on the reference side are corrected and matched so that the predetermined clearance is left.

[0006]

[Operation] According to this method, when the die and the punch are fitted together and the molds are matched, the reference plane extending in the direction in which the die and the punch approach each other is interposed at the position where excess thickness is to be formed from the workpiece. The thrust force received from the insert material is sufficiently counteracted by the wall portion extending generally in the direction in which the die and punch approach each other at the position where the product is formed from the workpiece, so that the thrust force received from the insert material is sufficiently counteracted by the die or punch. can be prevented from escaping due to the influence of thrust force, and therefore, the clearance measurement results can be made more accurate.
The shape of the reference side of the die and punch can be accurately corrected, and the shapes can be precisely matched.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a drawing die for a semi-finished product 2 used in manufacturing the rear side panel 1, manufactured by applying an embodiment of the drawing die manufacturing method of the present invention. In the figure, parts similar to those in the conventional example are designated by the same reference numerals. Further, FIG. 2 is a longitudinal sectional view showing the cross-sectional shape of a portion 2a that will become the rear fender portion 1a of the rear side panel 1 and an excess thickness 2b of the semi-finished product 2. As shown in FIG.

The method of manufacturing the drawing die in this embodiment is basically the same as the conventional method. First, the punch 3 is formed to accurately follow the shape of the inside of the semi-finished product 2, and then A blank holder 4 that can be moved up and down is formed outside the punch 3, and the punch 3 and blank holder 4 are used as a reference side, and a die 5 is placed outside the semi-finished product 2 so as to fit into the punch 3. The die 5 is formed to roughly follow the shape of the die 5, and the die 5 is set as the reference side.Then, the die 5, the punch 3, and the blank holder 4 are set on the ram 6 and bolster 7 of a press machine, respectively. An appropriate number of inserts 8, which are small pieces of soft metal such as lead that deform plastically, are inserted between each part of the die 5 and the punch 3, and the die 5 and the punch 3 are temporarily moved to a predetermined relative position as the ram 6 moves up and down. The clearance between each part of the die 5 and the punch 3 can be calculated by measuring the thickness of each insert 8 that has been crushed by being pinched between the die 5 and the punch 3. After that, based on the measurement results, the shape of the die 5 on the reference side is corrected and matched so that a predetermined clearance corresponding to the thickness of the plate-like workpiece is left.

However, in this method, when setting the shape of the semi-finished product 2 formed by drawing, unlike the conventional method, as shown in FIG. A vertical wall portion 2c extending in the vertical direction, which is the approach direction, is set, so that when the die 5 and punch 3 are initially formed, the extra wall portion 2b of the die 5 and punch 3 is formed from the plate-shaped workpiece. On the punch 3 side, as shown in a perspective view in FIG. 3 by cutting a part of the punch 3, reference planes 5c and 3c, which are approximately parallel to each other and extend in the vertical direction, are provided at positions 5a and 3a, respectively. The intervening material 8 is also inserted between the reference surfaces 5c and 3c when performing the above mold matching.

According to this method, when performing the above-mentioned die matching, the thrust force F3 that the reference surfaces 5c and 3c of the die 5 and the punch 3, which extend in the above-mentioned vertical direction, receive from the insert 8 is
is the part 2a that will become the rear fender part 1a from the plate-shaped workpiece.
Since the vertical wall portions extending approximately vertically at the positions 5b and 3b forming the die 5 sufficiently counter the thrust force F1 received from the intervening member 8, it is possible to prevent the die 5 from escaping due to the influence of the thrust force. Therefore, since the clearance measurement result can be made accurate, the shape of the die 5 can be accurately corrected and the shape can be accurately matched.

[0011] According to the drawing die manufactured by the method of the above embodiment, even when forming the semi-finished product 2 by drawing a plate-like work, the reference planes 5c, 3c extending in the vertical direction are
Since this balances the thrust force in the horizontal direction, breakage of the plate-like workpiece and generation of wrinkles in the semi-finished product 2 can be effectively prevented.

Although the above has been explained based on the illustrated example, the present invention is not limited to the above-mentioned example. For example, when performing die matching, the die may be placed below the punch and the punch side may be lowered. It is also possible to use the punch as the reference side. The present invention can also be applied to the production of drawing dies for products other than the above examples.

[0013]

[Effects of the Invention] Thus, according to the drawing die manufacturing method of the present invention, it is possible to prevent the die or punch from escaping due to the influence of thrust force, and therefore, it is possible to make the clearance measurement results accurate. , the shape of the reference side of the die and punch can be accurately corrected and the shapes can be precisely matched.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a semi-finished drawing die used in manufacturing a rear side panel, manufactured by applying an embodiment of the drawing die manufacturing method of the present invention.

FIG. 2 is a longitudinal cross-sectional view showing the cross-sectional shape of a portion of the semi-finished product that will become the rear fender portion of the rear side panel and the excess thickness.

FIG. 3 is a partially cutaway perspective view of the punch of the drawing die.

FIG. 4 is a front view showing a rear side panel as an example of a product manufactured using drawing forming.

5 is a cross-sectional view taken along line A-A in FIG. 4, showing the cross-sectional shape of the rear fender portion of the rear side panel.

FIG. 6 is a longitudinal cross-sectional view showing the cross-sectional shape of a portion of a rear side panel that will become a rear fender portion and excess thickness of a conventional semi-finished product.

FIG. 7 is a longitudinal sectional view showing a semi-finished drawing die used in manufacturing a rear side panel, manufactured by a conventional drawing die manufacturing method.

[Explanation of symbols]

1 Rear side panel 1a Rear fender section 2 Semi-finished product 2a Part that will become the rear fender section 2b Extra thickness 2c Vertical wall section 3 Punch 3a Position 3b for forming extra thickness 2b from the plate-shaped workpiece
Position 3c for forming the part 2a that will become the rear fender part 1a from the plate-shaped workpiece Reference surface 4 Blank holder 5 Die 5a Position 5b for forming the extra thickness 2b from the plate-shaped workpiece
Position 5c for forming the part 2a that will become the rear fender part 1a from the plate-shaped workpiece Reference surface 6 Ram 7 Bolster 8 Interposition material

Claims (1)

[Claims] 1. When manufacturing a drawing die that performs drawing on a plate-shaped workpiece by working together with a die and a punch that fit into each other with a predetermined clearance, the die and the punch,
A reference surface extending in the direction in which the die and punch approach each other is formed at a position where extra thickness is to be formed from the workpiece, and the product is removed between the reference surfaces of the die and punch and from the workpiece. By inserting inserts that plastically deform between the positions to be formed, fitting the die and punch together, and then separating them and measuring the thickness of the insert, the thickness of the die and punch is measured. The method is characterized in that the clearance between the positions where the product is formed from the workpiece is measured, and based on the measurement result, the shape of the reference side of the die and punch is corrected and matched so that the predetermined clearance is left. , How to make a drawing die.