JPH04300098A - Press die device - Google Patents

Abstract

PURPOSE:To prevent the position gap of the upper die part and the lower die part by receiving the sliding surface of the guide post and the bush partially with the plane surface, and attaching the plane structured part of plural pieces of guide post in the different direction mutually. CONSTITUTION:The punch 18 and the pad 19 of the upper die 13 are lowered, combinated with the lower die part 12, then the shedder 16 having the bush 17 of the lower die 12 is lowered along plural pieces of the guide post 14, and the shadow mask material is formed to the prescribed shape. In this time, because plural pieces of the guide posts 14 are formed to the plane surface at its surrounding and respectively different directions, so the clearance of the bushes 17 and the guide posts are kept against the thermal expansion of the shedder 16, the smooth lowering motion of the lower die 12 is allowable. That is, because one part of the surrounding surface of the guide posts are made to the plane surface structure, if the shedder 16 is expanded with heat, the structure becomes so as to escape the elongation of the shedder having the tubular bush 17, so the moving can be done and the position gap of the upper and lower dies 12, 13 can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press mold apparatus, and particularly to a guide post structure for a warm press mold suitable for press molding shadow masks for color cathode ray tubes.

0002

2. Description of the Related Art Conventionally, a press mold used for forming a shadow mask for a color cathode ray tube has been a molding method using a room temperature press mold in which the mold is not heated. As shown in FIG. 4, this cold press mold has a guide post 4 for receiving the mold, and this guide post structure has a cylindrical shape. The bush 7 that slides and is fitted into this guide post has a similar shape and is cylindrical.

0003

[Problems to be Solved by the Invention] In recent years, in color cathode ray tubes, the absolute amount of the electron beam emitted from the electron gun colliding with the shadow mask has increased due to higher definition and flattening, and the shadow caused by this has increased. Thermal expansion of the mask also became significant. For this reason, a new problem has arisen in that the relative positional relationship between the electron beam passing light and the fluorescent film changes, resulting in a doming phenomenon on the screen. To address this issue, we adopted an Invar material with extremely low thermal expansion for the shadow mask plate.

However, invar material shadow masks have the disadvantages of a large degree of springback due to the low Young's modulus of the material, poor formability in press molding, and unstable curvature. Improvements in the molding method have been desired.

[0005] For example, a method has been considered in which the processing temperature is raised to a high temperature in the dulling step, which is pre-treatment of the material, but this has the drawbacks of increased costs due to the heat-resistant structure of the equipment and deterioration of working conditions.

[0006] Therefore, the present invention has been proposed to solve the above-mentioned drawbacks, and an object of the present invention is to propose a new and improved warm press mold.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention adopts a structure in which the sliding surfaces of the guide post and the bush are partially supported by a flat surface, thereby absorbing the elongation due to temperature expansion of the mold. Provide mold equipment.

In particular, in order to improve the positioning accuracy of the shedder section of the lower mold, a mold device is provided in which the planar structure parts of a plurality of guide posts are attached in different directions.

[0009]

[Operation] According to the above structure, since the sliding surfaces of the guide post and the bush are received by a flat surface, the escape direction due to thermal expansion of the guide post is restricted.

Furthermore, by attaching a plurality of guide posts in different directions, it is possible to absorb the backlash of the mold, leading to an improvement in the accuracy of the combination of the upper mold part and the lower mold part.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A warm press mold apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is an exploded cross-sectional structural view of the warm press mold apparatus of the present invention.

FIG. 2 is a plan view of the lower mold in FIG. 1. In FIG. 1, the press mold apparatus of the present invention is comprised of a back plate 11 which is a substrate, a lower mold part 12 on this plate, and an upper mold part 13 opposite to the lower mold part 12. A guide post 14, which is a feature of the present invention, is fixed to the back plate 11, and a die 15 and a shedder 1 are fixed to the back plate 11.
It supports the lower mold part 12 consisting of 6. That is, the bush 17 integrated with the shedder 16 is connected to the guide post 1.
Although the die 15 is fitted into the guide post 4 and is slidable, the die 15 is stopped at the top surface of the guide post 14. Upper mold part 13
consists of a punch 18 facing the shedder 16 and a pad 19 facing the die 15, and the molding member between the mold parts 12 and 13, for example, a shadow mask plate for a cathode ray tube, is pressed down into a predetermined shape by the upper mold part. Molded into.

As shown in FIG. 2, the present invention is characterized by the cross-sectional shape of the guide post 14 and its arrangement structure, and also by the cross-sectional shape of the bush 17 of the lower mold part 12. More specifically, it is a combination of the guide post 14 of the substrate plate 11 and the bush 17 of the lower mold part 12 as shown in FIG.

Next, the operation of the above-mentioned warm press mold apparatus will be explained. Punch 18 and pad 19 of upper mold part 13
is lowered and engaged with the lower mold part 12, and then the shedder 16 having the bush 17 of the lower mold part is lowered along the plurality of guide posts 14 to mold the shadow mask material into a predetermined shape. At this time, as shown in FIG. 2, since the plurality of guide posts 14 form a plane around the periphery and are oriented in different directions, the clearance between the bush 17 and the guide post 14 is maintained against thermal expansion of the shedder 16. This allows the lower mold part 12 to move downward smoothly. That is, by forming a part of the peripheral surface of the guide post 14 into a planar structure, even if the shedder 16 expands thermally, the structure allows the extension of the shedder having the cylindrical bush 17 to escape.
It is operational. In addition, as shown in FIG. 2, by arranging the planes of the plurality of guide posts 14 in different directions, it is possible to eliminate misalignment between the upper mold part 13 and the lower mold part 12, making assembly easier. Leads to improved accuracy.

[0015]

As described above, in the present invention, the circumferential surface of the guide post is partially flat, and by receiving the bush on this flat surface, the escape direction due to thermal expansion is restricted. In addition, the lower mold can operate smoothly. In addition, by arranging the flat parts of the multiple guide posts in different directions, it is possible to prevent misalignment between the upper mold part and the lower mold part, resulting in extremely high precision, especially in the molding of shadow masks for color cathode ray tubes. was gotten.

[Brief explanation of drawings]

[Fig. 1] A sectional view showing the disassembled state of the warm press mold device according to the present invention.

[Figure 2] A plan view showing the arrangement of multiple guide posts in the lower mold part of the warm press mold device.

[Figure 3] Enlarged perspective view of the guide post and bushing in the lower mold section of the mold device

[Figure 4] Enlarged perspective view of a conventional guide post and bushing

[Explanation of symbols]

11 Back plate 12 Lower mold part 13 Upper mold part 14 Guide post 17 Bush

Claims (3)

[Claims] 1. A mold device that combines an upper mold part having a punch and a pad, and a lower mold part having a bush supporting a guide post upright on a plate, wherein the guide post is attached to a part of the outer periphery. While forming the part into a planar shape,
A press mold device characterized in that a part of the inner periphery of the bush is formed into a planar shape so as to fit the guide post, and each of the planar surfaces are arranged in different directions. 2. The warm press mold apparatus according to claim 1, for press-molding a shadow mask plate for a color cathode ray tube. 3. A press metal comprising a guide post fixed to a back plate and a bushing of the mold part slidingly fitted therein, the sliding portion of the guide post being partially chamfered. type device.