JPS6368225A - Press metal die for burring work - Google Patents

Abstract

PURPOSE:To prevent burring cracks and to improve burring work by installing a means uniformly pushing out projected top faces by use of three knockouts and always and uniformly pushing out the projected top faces even if the height of the embossed faces are uneven. CONSTITUTION:Three knockouts 13a, 13b, 13c pushing out projected top faces 9a, 9b, 9c of a stock 8 to be worked are independently installed. The stock 8 is previously drawn and then is burred. At the burring, the embossed top faces 9a and 9c at both sides are concurrently pressed by the knockouts 13a and 13c. The center projected top face 9b is pressed by the knockout 13b through a rod 14. The top of a 1st base 15 is a tapered projection 16 and presses the knockouts 13a, 13c by the force of a spring loaded on a 2nd base 17. The burring work limitation is improve and burring cracks are reduced by the press metal die.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a press mold that performs burring while pressing each of three projecting crests arranged in-line like a burring part for an electron gun of a color cathode ray tube. Regarding the improvement of

[Conventional technology]

This will be explained by taking the main lens electrode of a color cathode ray tube in-line electron gun as an example.

Conventionally, such a main lens electrode component has been made into a single flat plate, which is stretched out and then burred to form a three-dimensional shape as shown in FIG.
The electrode 3 is formed by integrally molding a lens part 2 having two cylindrical parts 1 in close proximity in an in-line manner. The structure of a press die for performing this burring process is shown in FIG. As shown in this figure, three projecting zenith surfaces 9a,
The upper mold knockout 4 that presses 9b and 9C is the base 5
The structure of the mold was such that the spring 6 was used to press and burr the projecting top part.

[Problem that the invention seeks to solve]

However, because the plate thickness of the three overhanging zenith parts was reduced, the surfaces were not necessarily flat and the overhanging heights were uneven. For this reason, a uniform suppressing force could not be exerted at the tip of the upper mold knockout 4, resulting in the problem of cracking of the bar link, which was a cause of quality deterioration.

Therefore, an object of the present invention is to provide a press die that improves the burring process limit.

[Means for solving problems]

In order to achieve the above object, the present invention provides a mold in which three protruding crests are burred in close proximity in an inline manner, and the burring is performed while pressing the protruding crests with a knockout against the processing direction of the burring punch. The knockout that presses the three overhanging crests is characterized by a knockout structure that can always be suppressed uniformly even if the overhang heights are uneven due to the reduced plate thickness of the overhanging crests.

[Effect]

With this configuration, even if the height of the overhang is uneven, the three knockouts can always suppress the top of the overhang evenly, improving the burring processing limit.
Burring cracks can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. still,
The same members and portions as in FIGS. 2 and 3 will be described with the same reference numerals.

FIG. 1 shows a mold for performing three burring operations on an oval irregularly shaped cup drawing. The workpiece 8 is a part before burring that has three overhangs. Three knockouts l pressing the overhanging zenith surfaces 9a, 9b, and 9c
3a + 13b + 13c are independent, the projecting zenith surfaces 9a and 9c on both sides are suppressed by knockouts 13a and 13c, and the center projecting zenith surface 9b is suppressed via a rod 14 movable by a spring. ,
Press with knockout 13b. The upper part of the first base 15 has a convex taper 16 and presses the knockouts 13a and 13c with a spring force applied to the second base 17. This causes the zenith surfaces 9a and 9b to protrude.

Even if the projecting heights are uneven due to the reduced thickness of the plate 9c, the three knockouts 13a, 13b, and 13c can always press the projecting top portion evenly.

〔Effect of the invention〕

According to the present invention, even if the height of the overhang is uneven, the three knockouts always press the top of the overhang evenly, improving the burring processing limit, reducing burring cracks, and improving quality. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the mold structure for burring according to the present invention, and FIG. 2 is a main lens electrode of an integrated in-line electron gun, (a) is a plan view, (b) is a sectional view, and FIG. 3 is a sectional view showing a conventional burring mold structure. 1... Burring cylindrical part, 2... Lens part, 3...
-Electron gun electrode, 6...upper spring. 7... Burring die, 8... Workpiece, 9a, 9
b, 9c...Protruding zenith surface, 10...Lower die knockout, 11...Lower die spring, 12---Punch, 13a, 13b, 13c...Upper die knockout, 1
4... Rod, 15... First base, 16...
convex taper, 17... second base, 18... lower die;

Claims (1)

[Claims] 1. In a mold in which burring is performed on the overhanging zenith surface of three in-line rows, the knockouts that press the overhanging crest on both sides are , has a tapered first base with a flat knockout side, a spring force is applied to the tapered convex portion of the first base via a second base whose both sides are flat; There is a knockout in the hole in the center of the base that presses the overhanging top of the center.
A press mold for burring processing, characterized in that a spring force different from the spring applied to the second base is applied, and burring is performed while uniformly pressing each of the three projecting crests.