JPH0287880A - Forming of enclosure in television receiver - Google Patents

Abstract

PURPOSE:To obtain a strong structure by applying effectively secondary pressure by forming a bezel one-body type cabinet by using a thimbleless formation, and also, injecting high pressure gas to at least a holding part of a CRT. CONSTITUTION:A bezel integrated cabinet 10 is formed by a dies 19, 20 by using a thimbleless forming method. From an injection cylinder 22, a molten resin 24 is injected to a cavity of the dies 19, 20 through a gate 21, and subsequently, a little later, gas in a gas press-in cylinder 25 is compressed by a piston 26, and this gas is injected into a cavity through a torpedo 28 and a gas injection port 29. As for the cabinet 10 which is formed in such a manner, especially to a wall thickness part 16 of its corner, secondary pressure is applied by gas, therefore, not only a piping defect can be prevented but also a thick stop boss can be formed by gas pressure. In such a manner, only a holding part of a CRT can be formed to a storing structure by a short forming cycle, and also, by the plate thickness of the same degree as that of a regular formed part.

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD will face the opening of the bezel. A mounting piece is provided at the corner of the CRT, and this mounting piece is fixed to a holding part of a cabinet or bezel. As the CRT becomes larger, its mm also becomes larger, so it is necessary to adopt a strong structure for mounting the CRT. Therefore, an independent bracket made of a molded body is prepared and installed at the corner of the cabinet. Another method is to use low-foaming molding to reduce the thickness of the holding part. K Problems to be Solved by the Invention] If a molded bracket made of separate members is used to mount a large CRT, not only will the number of parts increase, but the means for fixing the bracket to the cabinet will be required. , which increases costs. Low-foam molding involves injecting a resin containing a foamed material together with a normal resin, but the molding cycle is long, which has the disadvantage of reducing molding productivity. The present invention was made in view of these problems, and does not require the use of a bracket made of a separate member, does not require a long molding cycle like low-foam molding, and, moreover, does not require the use of a bracket made of a separate member. It is an object of the present invention to provide a method for molding a casing of a television receiver that has a high strength.

[Means to solve the problem]

The present invention uses a thin press molding method in a method of molding a housing such as a bezzle-integrated cabinet having a holding part for holding a CRT or a pezil by injection molding of synthetic resin.
The system is designed to inject high pressure gas into the holding section. 1 Effect] Therefore, high pressure gas is injected into the inside of the CRT holding part, and this gas pressure effectively applies secondary pressure to the CRT holding part to make the CRT holding part a strong structure. becomes possible.

【Example】

FIG. 4 shows a cabinet 10 for a television receiver molded by a method according to an embodiment of the present invention. It makes up a cabinet. A rectangular opening 11 is formed in the bezel portion at the front end of the cabinet 10, and the CRT 12 is housed in the cabinet 10 so that the screen surface faces the opening 11. The CRT 12 has mounting pieces 13 at each of its four corners, and these mounting pieces 13 are formed at the four corners of the cabinet 10, as shown in FIGS. 1 and 2. It is fixed to a stop boss 14 with a tapping screw. stop boss 1
4 are reinforced by ribs 15 and are provided in thick walled portions 16 at four corners of the cabinet 10. As shown in FIGS. 2 and 3, such a bezel-integrated cabinet 10 is molded by a thin press molding method using molds 19 and 20. Mold 1
As shown in FIG. 3, the mouthpiece of an injection cylinder 22 is connected to the gate 21 for injecting the resin 9.20. A screw 23 is held within the injection cylinder 22, and the screw 23 extrudes the molten resin 24. Further, a gas injection cylinder 25 is connected to the injection cylinder 22 . A piston 26 is held in the gas injection cylinder 25 so as to be openable. A gas supply source is further connected to this cylinder 25 via a valve 27. In addition, the discharge side of the gas press-in cylinder 25 is an injection cylinder 22.
The torpedo 28 is connected to the torpedo 28 held at the discharge port. Two gas injection ports are attached to the tip side of the torpedo 28. Furthermore, cabinet 1
The mold for molding the cabinet 10 is provided with four gates 21 at its corners, as shown in FIGS. will be used. In the above configuration, the molten resin 24 passes through the gate 21 from the injection cylinder 22 shown in FIG. 3 and enters the mold 19.
Injected into 20 cavities. Then, a little later than the injection of the molten resin 24, the piston 26
The gas in the gas injection cylinder 25 is compressed, and this gas is injected into the cavity through the torpedo 28J5 and the gas injection port 29. The supply of gas pressure by the cylinder 25 continues even after the pressurization of the molten resin 24 has ended. Gate 21 of cabinet 10 formed in this way
A space 32 is formed by the injected gas in the thick wall portion 16, which is near the thick wall portion 16 and is particularly thick. And this space 3
Since secondary pressure is applied by gas pressure to the thick wall portion 16 through the cabinet 10, pressure is applied to the inside of the cabinet 10 at its corners without any loss. The cabinet 10 formed by such thin press molding is not only able to prevent sink marks, but also to prevent sink marks, especially since the thick corners 16 are subjected to secondary pressure due to the gas pressure. It becomes possible to form a thick stop boss 14. In other words, conventionally it was only possible to form a stop boss for screwing in a tapping screw with a diameter of 5 nm, but by applying secondary pressure from gas, it is now possible to form a boss 14 into which a tapping screw with a diameter of 7 nm can be screwed. become. In addition, by forming a space 32 in the thick corner part 16 and applying secondary pressure through this space 32,
The strength of the corner part is improved, and this improves the strength of the stop boss 1.
4, it becomes possible to securely hold the heavy CRT 12. Therefore, is it a normal molded product P? ! This makes it possible to design the vicinity of the holding portion 14 of the CRT 12 to be as thick as possible and to be strong. By employing such thin press molding, the cycle time does not improve as with low foam molding, and the cabinet 10 to which the large CRTI 2 is directly attached and fixed can be efficiently molded. K Application Example] Although the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the technical idea of the present invention. For example, although the above embodiment relates to a method for molding a cabinet with an integrated bezel, the present invention is also applicable to a method for molding a bezzle having a CRT holding portion. Effects of the Invention 1 As described above, the present invention uses the thin press molding method and injects high-pressure gas into at least the holding portion of the CRT. Therefore, it is possible to provide a television receiver casing in which only the CRT holding part has a strong structure, with a short molding cycle, and with the same plate thickness as a normal molded product.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a cabinet according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line ■ to ■ in Fig. 1, and the third factor is a cross-sectional view of the main part of the resin injection device; Fig. 4 FIG. 2 is an external perspective view showing how a CRT is attached to a molded cabinet. The names of the main parts in the drawings are as follows. 10φ...Cabinet 12...CRT 13...Mounting on piece 14...Stopping boss 16...Thick wall part 22...Injection cylinder 25... ...Gas pressure cylinder 32...Space

Claims (1)

[Scope of Claims] 1. In a method in which a housing having a holding portion for holding a CRT is molded by injection molding of synthetic resin, a thin press molding method is used, and at least the holding portion for holding the CRT is A method for molding a casing of a television receiver, characterized in that high pressure gas is injected into the casing of a television receiver. 2. The method for molding a cabinet for a television receiver according to claim 1, wherein the casing is a bezzle-integrated cabinet or a bezzle.