JPS6127332B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing an envelope-shaped glass flat plate by heating a glass circular tube.

The envelope-shaped flat glass plate is used, for example, as a discharge electrode in a silent discharge device. Glass circular tubes are produced in large quantities using a well-known glass tube drawing machine known as a Danner machine, which is cut into appropriate lengths and coated with a conductive coating on the inner surface of the glass tube.
Alternatively, after wrapping a conductive metal film inside a glass tube, place it on a heat-resistant mold and heat it in an electric furnace to the softening temperature of the glass, the glass tube becomes flat and becomes an envelope-shaped glass flat plate. can be obtained. In a silent discharge device, a discharge electrode made of an envelope-shaped glass flat plate is inserted into a separately provided metal sheath, keeping an appropriate gap between the sheath and the glass flat plate.
The sheath is used as a ground electrode, and the conductive film in the glass plate is used as a high voltage electrode to generate a discharge.

By the way, when heating a glass circular tube to manufacture an envelope-shaped glass flat plate, the glass circular tube is placed on a smooth mold and moved into an electric furnace together with the mold. Traditionally, a stopper was placed on top of the mold to prevent it from rolling, but when the envelope-shaped glass was completed, the stopper remained and the glass flat plate became concave in that area. I end up. FIG. 1 is an explanatory diagram of this conventional example, in which 1 is a heat-resistant mold, 2 is a glass circular tube, and 3 is a stopper. , FIG. 1A shows the state before heating, and FIG. 1B shows the state after heating.
2' is a state in which the glass circular tube has become an envelope-shaped flat plate. In addition, in order to improve the envelope-like shape, the conventional method was to place an upper mold on top of the glass cylinder 2 and heat it while applying pressure to the glass cylinder 2, as shown in the cross-sectional view of Figure 2. Since the glass tube was prone to rolling, the upper mold shifted during heating, making it difficult to manufacture the product.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks and provide an apparatus for manufacturing a perfectly shaped envelope-shaped glass flat plate.

In order to achieve this object, the present invention provides a support part to prevent the glass circular tube from rolling on the mold when it is placed on the mold before heating, and also provides a support part to prevent the glass circular tube from rolling on the mold when it is placed on the mold before heating. It is characterized by a structure in which it does not come into contact with this support part when it becomes a flat plate.

The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 3 is a plan view thereof, and FIGS. 4A and 4B are sectional views taken in the direction A and B of FIG. 3, respectively. In the figure, 1 is a lower mold made of a heat-resistant material such as heat-resistant steel, graphite plate, ceramic plate, etc., and its upper surface is finished smooth. Reference numeral 2 denotes glass circular tubes, and although three tubes are shown lined up in the figure, there is no limit to the number in the present invention. 4 is an upper mold, which is made of a heat-resistant material like the lower mold, and its lower surface is finished smoothly. A shaft 5 is fixed to the lower die 1 and is made of a heat-resistant material. Reference numeral 6 denotes a glass circular tube support that is rotatable around an axis 5, and has claws 7 on one side, and the claws maintain a distance from each other so that they do not come into contact with each other when the glass circular tubes 2 are heated and become flat. Support the upper half of the glass tube obliquely. 8 is the support 6
It is fixed to the shaft 5 with a stopper to prevent the support from moving along the shaft.

When the apparatus configured as described above is gradually heated in a heating furnace to the softening temperature of the glass circular tube, the glass circular tube gradually becomes flattened, and the upper die 4 gradually becomes lower in position. At this time, the upper die 4 is attached to the claw 7 of the support 6.
As the support member 6 is pushed downward, the support member 6 rotates around the shaft 5, and the claws are finally removed from the glass circular tube. In this state, the glass circular tube is already flat, so it does not roll and move on the mold, but is crushed into a predetermined envelope-shaped flat glass plate.
The next step is to slowly lower the temperature to avoid damaging the glass, and the process is complete.

FIGS. 5A and 5B are sectional views corresponding to FIGS. 4A and 4B showing this state.

Although not shown, the inside of the glass circular tube 2 is subjected to necessary treatments in advance depending on the use of the envelope-shaped glass flat plate. For example, in the case of a silent discharge electrode, a conductive coating film mainly made of carbon is applied to the inner surface of a glass circular tube, or a conductive lead wire is installed and then heated. Further, by placing a spacer on the lower mold 1 to regulate the distance from the upper mold 4, the thickness of the envelope-shaped glass flat plate can be made constant. In addition, if there is a possibility that the glass circular tube 2 and the upper and lower molds may be welded together, you can apply a carbon-based mold release agent to the mold or insert seceramic paper between the mold and the glass. good.

In the figure, the support 6 is arranged in a Yajirobee manner so that the weight of the claw 7 and the opposite side of the claw are balanced, but a spring made of a heat-resistant material may be used to lightly push the claw toward the glass circular tube.

According to the present invention, the glass circular tubes can be kept in extremely stable positions, so that they can be stacked in two, three or more layers. FIG. 6 shows a case where it is assembled in two stages. The symbols in the figure are the same as in FIG. 4, and 9 is the medium size. FIG. 7 shows a state in which the apparatus shown in FIG. 6 is heated and the glass is softened and becoming flat. Similarly, by assembling three or more stages, a large amount of envelope-shaped flat glass plates can be manufactured at one time.

As is clear from the above description, according to the present invention, a highly accurate envelope-shaped glass flat plate can be efficiently manufactured from a glass circular tube.

[Brief explanation of the drawing]

Figure 1 is a diagram for explaining the drawbacks of the conventional device.
Figure 2 is an explanatory diagram of the conventional manufacturing method, Figures 3 and 4.
5 and 5 show one embodiment of the present invention, and FIGS. 6 and 7 show other embodiments of the present invention. DESCRIPTION OF SYMBOLS 1...Lower mold, 2...Glass circular tube, 3...Stopper, 4...Upper die, 5...Shaft, 6...Glass circular tube support, 7...Support claw, 8... Support stopper, 9...medium size.

Claims (1)

[Claims] 1. A manufacturing device for manufacturing an envelope-shaped flat glass plate by heating a glass circular tube, which includes a lower mold that is located approximately horizontally and is made of a heat-resistant material with a smooth upper surface, on which the glass circular tube is placed, and an end portion of the lower mold. A cross-linked shaft made of a heat-resistant material is fixed to the shaft, and a heat-resistant material is attached to the shaft and is rotatable around the shaft and capable of supporting the end of the glass circular tube with the glass tube placed on the lower mold. and an upper mold made of a heat-resistant material and having a smooth lower surface for weighting the glass circular tube, and the upper half of the glass tube is supported by the nails. Glass flat plate manufacturing equipment.