JPS5810348A - Manufacture of explosion-proof picture tube - Google Patents

Abstract

PURPOSE:To enable an annular body to be fixed around the largest-diameter part of a picture tube, without performing any troublesome three-dimensional press formation work, by inserting the said largest-diameter part into a heated expanded annular body, and rapidly cooling the said annular body so as to make it to be deformed in accordance with the shape of the outer circumference wall of the picture tube during the cooling contracting process. CONSTITUTION:Picture tube supporting protruding-lug metallic members 17, 18, 19 and 20 are welded to the four corners of an almost rectangular annular body 16, which is formed tow-dimensionally by use of a formation metallic-mold, before the annular body 16 is taken out of the above metallic mold. Next, the annular body 16 taken out of the metallic mold is fixed to the smooth top surfaces of four struts 21, 22, 23 and 24 of a shrink-fit work stand by using the metallic members 17, 18, 19 and 20 provided on the four corners of the annular body 16 as supports, and is heated with a gas burner 25 placed inside the annular body 16. After that, a face panel 28 of a picture tube body 27 is pressed and fitted inside the heated expanded annular body 16, and an air stream or the like is immediately supplied to the press-fit part so as to make the annular body 16 to be rapidly cooled. Thus, quenching fitting work is completed, and the picture tube body 27 is tightly fastened with the annular body 16 attached around the face panel 28.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an explosion-proof picture tube comprising a picture tube body and a metal ring shrink-fitted to the outer peripheral surface of the largest diameter portion of the picture tube body.

Conventionally, a metal ring was shrink-fitted to the outer circumferential surface of the largest diameter part of the picture tube body to create an explosion-proof structure. It has the advantage of not being easily ruptured. The method of shrink-fitting a pre-formed metal ring into the largest diameter part of the picture tube body is not only more efficient in mass production than the so-called tension band method, which is wrapped around the largest diameter part of the picture tube body and tightened. , it is possible to apply a strong and uniform clamping force to the picture tube body. Another advantage is that projecting ear fittings for supporting the picture tube can be attached in advance to the four corners of the metal ring at positive (lrf) positions.

By tightening the outer peripheral surface of the maximum diameter part of the picture tube body with a conventional metal band made of a high tensile strength steel plate, for example, 80KQ/-,
The reinforcing method of welding or clamping the winding start end and end winding end of a metal strip to each other has the following drawbacks. In other words, the metal band for tightening the picture tube is
Because it has a tensile strength that is about 4 to 5 times higher than normal mild steel, it does not deform easily, and even if the picture tube is tightened with great force, it will conform to the shape similar to the outside shape of the picture tube. It does not deform, and the tightening force is unstable. After the tightening, when welding the starting and ending ends of the metal strip, the welding electrode is inserted between the picture tube and the metal strip. After welding is completed, we will remove this electric converter, so
The metal band loosens by this gap, making it impossible to tighten it sufficiently and causing variations in the tightening force. These things lead to serious deficiencies in this reinforcement system. In addition, since the metal fittings for fixing the picture tube are sandwiched between the picture tube and the above-mentioned metal band, the position of the fixing metal fittings cannot be accurately regulated, and the position varies widely. It was difficult to mount it onto the chassis of a TiVision receiver using an automatic machine.

According to the method for manufacturing an explosion-proof picture tube of the present invention, a metal band made of a steel plate with a low yield point of, for example, 23 kg/myi is joined at both ends to form a ring-shaped body, and then a two-dimensional The circumferential length of the band is precisely determined by molding, and a rectangular annular body having an inner circumferential shape very similar to the outer circumferential shape of the maximum diameter portion of the picture tube body is obtained. This annular body is heated and expanded, the largest diameter portion of the picture tube body is inserted into it, and then the annular body is rapidly cooled.

In this way, the annular body that comes into pressure contact with the outer circumferential surface of the maximum diameter part of the picture tube body in the process of cooling and shrinking deforms itself to match the shape of the outer circumferential surface, thereby eliminating the troublesome three-dimensional press forming process. The annular body can be shaped in a three-dimensional manner without the need for additional molding.

Next, a method for manufacturing an explosion-proof picture tube according to the present invention will be explained in detail together with embodiments shown in the drawings.

In FIG. 1, the first and second split molds 1゜2 form a substantially rectangular mold 3, and a metal band 4-:, thickness 0.4 arm-1,
The mold 3 is made of a low tensile strength steel plate with a width of 10m1 to 30m and a U-shaped first and second outer frame 5°6.
It's pressed to the side. Therefore, in this state, when the overlapping portions of both ends of the metal band 40 are welded using the welding rod 7, an annular body 8 of a predetermined size made of the metal band 4 is obtained.

Note that this annular body 8 rotates the first and second outer frames 5°6 about their respective support shafts 9 and 1o, and
By moving the second split p mold 2 toward the first split p mold 1 side, it can be removed from the mold 3.

The annular body 8 is then two-dimensionally molded using a mold as shown in FIG. That is, the annular body placed so as to surround the outer peripheral surface of the molding die 15 consisting of the first to fourth split molds 11, 12, 13° 14,
By moving the first to fourth split molds 11, 12, 13, 14 in the expanding direction of the arrow shown in the figure, the material is plastically worked two-dimensionally beyond its yield point, and its inner surface shape is The shape of the outer peripheral surface at the maximum diameter portion of the tube body is almost similar.

The residual elongation of the annular body material at this time is equal to or higher than the yield point (usually 0.1% or more), and the inner peripheral surface length of the annular body after molding is determined at the maximum diameter part of the picture tube body (pre-wrapped tape). The length of the outer circumferential surface of (including) is also 0.1-0.5%6., -7' shorter. Even if the residual elongation of the annular body material is below the yield point, it has a reinforcing effect, but the degree of this effect varies in proportion to the amount of residual elongation, making it impossible to obtain stable quality. In addition,
The monthly elongation that exceeds yield does not completely go to zero even when the load is removed, and some permanent deformation remains. The yielding phenomenon clearly appears in well-annealed pure iron, but in practically used mild steel and stainless steel, yielding begins at approximately 0.1 to 0.2% elongation. It is desirable that the elongation at yield point be smaller because the residual elongation can be reduced.

The approximately rectangular molded annular body 16 two-dimensionally molded by the molding die 15 is attached to a picture tube supporting ear fitting 17.1B before being taken out from the molding die 15.

19.20 are welded on the four corners. Since this electric welding is performed using the molding die 15 as one electrode, the four ear fittings 17, 18, 19, 20 are attached to the four corners of the molding annular body 16 with great precision.

The molded annular body 16 taken out from the molding die 15 is
As shown in the figure and Fig. 4, on the smooth top surfaces of the four pillars 21.22, 23.24 of the 7 and -7 joints, the four corner ear fittings 17.1B, 19°20 is fixed as a support. There are pins 2i&, 22&, 23a, 241L protruding from the top surface, and the position of the ear fitting 17.1 is adjusted by inserting these pins 21a, 22a, 23a, 24a.
8, 19.20 are presser pieces 21b, 22b.

It is clamped by 23b and 24b. The pressing force exerted by each pressing piece is 5 to 10Kq, and the molded annular body 16 supported in a predetermined position is heated by the gas burner 25 disposed inside the molded annular body 16.

When the molded annular body 16 is sufficiently expanded by this heating, the gas burner 26 is extinguished and lowered, and the picture tube holding stand 26 integrally provided with the gas burner 25 and a predetermined position of this stand 26 are vacuum-adsorbed. The well-supported picture tube body 27 is lowered, and the face panel portion 28, which is the largest diameter portion of the picture tube body 27, is inserted into the molded annular body 16, as shown in FIG. However, face panel part 2
Adhesive tape 2 to prevent thermal shock is attached to the outer circumferential surface of 8 in advance.
9 is wrapped. In addition, since the picture tube body 2, which is vacuum-adsorbed onto the holding table 26, must be correctly positioned at a predetermined position, the alignment point formed on the face channel and funnel of the valve on the picture tube body must be aligned. The position shall be adjusted to the correct value using a jig, etc., using the protrusion (for example) as a reference surface.

The heating temperature for elongating the formed annular body 16 depends on the material of the annular body, but is about 3°C to 800°C, and in the case of mild steel or stainless steel, it is 400°C to 650°C.
A range of is appropriate. If the heating temperature is too high, the annular body will be annealed and softened and will not be able to withstand a certain amount of tension, making it impossible to apply sufficient tightening force to the picture tube body.

If the outer peripheral surface length of the face panel portion 28 is 900 mm or more, the thermal expansion coefficient is 10ox 10'/C~
1 20X10-'/"C, tensile strength 18Kq/-
~36Kg/- mild steel can be used, and the outer circumferential surface length]
For small tubes with less than 900 ms+, the coefficient of thermal expansion,
Stainless steel having a tension strength of 30 Kl; l/- to 3 e Kg/- can be used.

The molded annular body 16 is rapidly cooled by immediately applying air flow to the press-fitted portions of the face panel 28 of the picture tube body 27 into the heated and stretched molded annular body 16. The cooler 3o shown in FIG. 6 has a large number of small nozzles on the surface facing the annular body 16, and the press-fitting section is uniformly cooled by air injected from the small nozzles.

The shrink fitting is thus completed, and the picture tube main body 27 is tightened by the annular body surrounding the face panel portion 28. The molded annular body 16 after shrink fitting is permanently deformed, plastically worked, and tightened at the yield point of the material. The shaped annular body 16, which has been subjected to secondary processing, deforms itself to match the shape of the outer peripheral surface at the maximum diameter portion of the picture tube main body 27, and is thus three-dimensionally processed.

In addition, since the rapid cooling gives a certain degree of burning effect to the annular body (for example, 23Kq/- soft 1o/,
7 steel becomes 32 Kq/-), the mechanical strength of the annular body increases and the amount of material used can be reduced by the increased tensile strength (approximately 40%).

[Brief explanation of drawings]

The drawings show an embodiment of the method for manufacturing an explosion-proof picture tube according to the present invention. FIG. 1 is a plan view showing the relationship between a mold and a metal band in the process of forming an annular body, and FIG. FIG. 3 is a plan view showing the relationship between the mold, the annular body, and the ear fitting in the forming process; FIG. The same perspective view, FIG. 6 is a side sectional view showing the relationship between the molded annular body and the picture tube body in the press-fitting process, and FIG. 6 is a plane view showing the relationship between the molded annular body, the picture tube body, and the cooler in the cooling process. It is a diagram. 3...Mold, 4...Metal band, 8.
...Annular body, 15...Molding mold, 16.
...Molded annular body, 17-20...Protruded ear fitting, 25...Gas burner, 2..... Picture tube body, 30... Cooler. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure ZΦ Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A metal band made of low tensile strength steel plate is two-dimensionally formed,
A step of obtaining a rectangular annular body having an inner peripheral surface shape approximating the outer peripheral surface shape of the maximum diameter part of the picture tube main body, and providing projecting ear fittings for supporting the picture tube at the four corners of the annular body on the mold for molding. a step of heating and elongating the annular body whose four corners are fixed by the ear fittings with a burner provided inside the annular body, and lowering the burner to fix the image receiving member inside the annular body. and a step of rapidly cooling and shrinking the annular body to give three-dimensional shaping to the annular body using the outer peripheral surface of the maximum diameter part. A method for manufacturing a characteristic explosion-proof picture tube.