JPH07114111B2 - Method of manufacturing low pressure metal vapor discharge lamp - Google Patents

Description

The present invention relates to a method for manufacturing a low-pressure metal vapor discharge lamp in which a plurality of glass tubes each having a discharge section having a flat cross section are connected to form a curved discharge path. Regarding

[Conventional technology]

Conventionally, U-shaped, W-shaped, saddle-shaped, etc. bending fluorescent lamps as well as ballasts, lighting tubes, and lighting circuit components such as capacitors are housed in an envelope, and this envelope is used for incandescent light bulbs. A fluorescent lamp device with a base attached has been developed, and since it has compatibility with an incandescent lamp, it is becoming popular as an energy-saving light source.

This type of fluorescent lamp device is currently under development toward further compactness and higher output.

The means usually used for compactification are to make the glass tube thin and to reduce the bending curvature.To make the bending curvature small, in other words, to make the glass tubes close to each other as close as possible to a meandering discharge It is to form a path. And, in some cases, the glass tubes are stuck together.

On the other hand, in order to increase the output, since the discharge path is made as long as possible in a limited space, the tube is made thin and the bending curvature is made small as in the case of the compact size.

When the tube diameter becomes smaller as described above, the temperature of the glass wall of the glass tube rises even if the lamp input is the same. Even if the lamp input that determines the heat generation amount of the lamp is constant, the surface area of the lamp that determines the heat radiation efficiency of the lamp becomes smaller as the diameter of the glass tube becomes smaller, so that the wall temperature of the glass tube rises.

Further, when the bending curvature becomes small, the glass tubes are arranged close to each other, which is the same as the presence of a heating element near the glass tube requiring heat dissipation, and the heat dissipation efficiency of each glass tube further decreases.

Therefore, the wall temperature of the glass tube rises, and as a result,
There is a drawback that the thermal deterioration of the phosphor becomes significant.

Further, the temperature rise of the glass tube brings about a problem that it becomes difficult to control the mercury vapor pressure as a fluorescent lamp.

Such a drawback is more remarkable when the entire fluorescent lamp is covered with a globe.

As means for improving such problems, flattening the cross-sectional shape of the discharge path has been studied. By making the cross-sectional shape of the discharge path flat, it is possible to increase the surface area of the glass tube without changing the cross-sectional area of the discharge path, that is, without changing the thinness of the tube, as compared with the case where the cross-sectional shape is circular. Therefore, the heat dissipation area of the glass tube is increased, and the temperature rise can be suppressed to a small level. Further, there are advantages that the area covered by the phosphor can be increased and the light emitting area can be increased.

By the way, in order to increase the output of a lamp, as described above, it is advantageous to make the discharge path as long as possible in a limited space. It is extremely difficult in terms of processing technology to form an arc tube having a flat discharge discharge path in cross section. Therefore, a means for connecting a plurality of glass tubes in which the cross-sectional shape of the discharge path is formed flat in advance is adopted.

A means for connecting a plurality of glass tubes to each other is disclosed in
As shown in Japanese Patent Publication No. 55-133730, there is known a method in which the wall of a glass tube is heated and softened and blown through, and the openings formed by this blow are fused together.

[Problems to be solved by the invention]

However, when connecting a plurality of glass tubes having flat discharge sections, the method disclosed in the above publication is used, for example, a glass tube having a flat discharge section as shown in FIG. When 90, 90 are made to communicate with each other by their fusion parts 91, it is not only difficult for the heating burner flame to reach evenly over the entire circumference of the fusion point, but this heating A wide area with a flat cross section is heated and easily deformed by the burner flame, and thermal strain remains on the blown peripheral wall surface, and cracks occur when baking after applying the phosphor in a later process. It causes it to occur.

Note that 92 is the base.

Therefore, an object of the present invention is to provide a method for manufacturing a low-pressure metal vapor discharge lamp capable of connecting glass tubes having discharge paths having a flat cross section to each other without leaving thermal strain.

[Means for solving problems]

According to the present invention, each glass tube has an opening formed by heating and softening a part of a narrow surface having a flat cross-sectional shape and blowing it off, and these openings are communicated directly or by using a communicating pipe. It is characterized in that the discharge paths of the respective glass tubes are communicated with each other through the connecting holes.

[Action]

According to such a method, the heating burner flame during fusion is less likely to be disturbed by a wide surface having a flat cross section, so that it is likely to be uniformly heated over the entire circumference of the fusion location, and the glass Only a narrow surface with a flat cross section needs to be heated for the tube, and residual strain is less likely to remain on the peripheral wall surface blown by the heating burner flame, thus reducing the occurrence of cracks.

Example of Invention

The present invention will now be described with reference to the first embodiment shown in FIGS.
A description will be given based on the embodiment of.

In the figure, 1 and 1 are glass tubes constituting an arc tube, and these glass tubes 1 and 1 are discharge paths 2 and 2 of substantially U-shape, respectively.
Is equipped with. As shown in FIG. 2, the discharge paths 2 and 2 have a flat cross section, and the discharge paths 2 and 2 of adjacent straight portions of each glass tube 1 are arranged so that their flat major axis directions coincide with each other. In other words, each glass tube 1 is formed in a substantially plate shape.

The glass tubes 1 and 1 having the above-described shapes can be integrally formed by heating and softening a glass tube having a large diameter and pressing the glass tube with a pair of molds.

The electrodes 3, 3 are sealed to one end of each glass tube 1, and the exhaust tubes 4, 4 are joined. The other end of each glass tube 1 is closed.

In connecting the glass tubes 1 and 1 configured in this way to each other, the following method is adopted. That is, the glass tube 1,
The side wall on the closed end side in 1 is heated by the heating burner 5. In this case, the side wall to be heated is a narrow surface having a flat cross section, that is, a flat side wall in the long axis direction, and heats a part at a position close to the closed end side.

The side wall heated by the heating burner 5 is softened.

The heating burner 5 shown in FIG. 1 has a bifurcated shape, and one burner can heat and soften two glass tubes 1, 1 at a predetermined position at the same time. May be softened by heating.

When the side wall is softened, a gas suitable for an inert gas is blown through the exhaust pipes 4, 4. This allows the glass tube 1,1
The gas pressure inside rises, and the softened portion is blown by the gas pressure as shown in FIG. Therefore, due to this blowout, the opening 6, which protrudes outward,
6 is formed.

Next, the glass tubes 1 and 1 are butted against each other at the openings 6 and 6, and are heated and fused by a burner 7 as shown in FIG.

By doing so, the glass tube having the discharge path 2 having a substantially U-shape
1, 1 are connected to each other at their end portions, and are electrically connected to each other through a connection hole 8 formed by fusion bonding. Therefore, the arc tube 9 having a long curved discharge path is formed.

A phosphor is applied to the inner surface of the arc tube 9 as described above, dried, and then baked.

Then, the fluorescent lamp is completed by evacuating the inside of the arc tube 9, sealing mercury and a rare gas for starting, and sealing the exhaust tube.

According to the above example, the heating burner 5 for blow-through
In either case of heating the glass tube 1 in the case of heating with the burner 7 for fusion bonding, the burner flame hits only the narrow surface where the cross section has a flat shape. Since it does not hit a wide surface as in the case of FIG. 9, the strain around the fused portion is reduced, and even if the glass tube is heated in the baking step after coating on the phosphor,
Less cracking occurs.

In such a fluorescent lamp, since the cross-sectional shape of the discharge path 2 is formed flat, the glass tube around the discharge path 2 has a flat cross section, and the cross-sectional area is the same as that of the circular shape. In addition, since the surface area is larger than that of the circular shape, the heat dissipation area is also increased, and the temperature rise of the fluorescent lamp can be reduced. In addition, the surface area is increased, so that the area covered by the phosphor can be increased and the light emitting area is increased.

When the shape is as shown in FIG. 4 and FIG. 5, the light emitting surface having a large area is directed outwards as compared with the case of FIG. It becomes a surface-shaped light emitting surface with a large area and becomes bright. That is, in the case of FIG. 9, since the light emitting surface of one glass tube faces the light emitting surface of the other glass tube, the lights emitted from these facing portions are mutually shielded and are not effectively emitted to the outside. In the shapes shown in FIGS. 4 and 5, since all the light emitting surfaces having a flat and wide area face outward, the amount of light effectively emitted to the outside increases.

Further, since both flat side surfaces having a large area face the outside, heat dissipation is also improved.

In the case of the above embodiment, the electrodes 3 and 3 were sealed to the glass tubes 1 and 1 in advance and the glass tubes 1 and 1 were joined together, but the glass tubes 1 and 1 were joined together. After forming the arc tube, the phosphor may be applied and baked to seal the electrodes 3 and 3.

Further, in the case of the above embodiment, the openings 6, 6 formed by blowout are directly butted, and they are fused so as to communicate with each other.However, when it is desired to separate the glass tubes 1, 1 from each other,
In the case where it is desired to connect them in a bent shape, a communicating tube 20 made of a glass thin tube as shown in FIG. 6 may be used as an intermediate connecting member to be fused with each other.

In addition, each glass tube has a U-shaped discharge path.
The present invention is not limited to the one provided with 2, 2 and can be implemented even when the glass tubes 30, 30 having a linear discharge path are connected as shown in FIG. 7.

Further, the number of glass tubes is not limited to two, and for example, as shown in FIG. 8, a large number of glass tubes 40 ... Can be connected in a circular shape as a whole. , In that case, the connection hole 8 formed by fusion bonding ...
In the case of a narrow surface having a flat cross-section, the meandering discharge paths can be formed as a whole by alternately connecting them in the vertical position. In FIG. 8, 41 is a case in which a lighting circuit component (not shown) is housed, and 42 is a base.

〔The invention's effect〕

As described above, according to the present invention, an opening is formed in a glass tube by heating and softening a part of a narrow surface having a flat cross-sectional shape and blowing it off. Alternatively, a fusion tube is used for fusion, and the connection holes formed by this fusion are used to connect the discharge paths of the glass tubes to each other.Therefore, when the fusion is performed, the heating burner flame has a wide surface with a flat cross section. Since it is not disturbed by the heat, it can be heated evenly over the entire circumference of the fusion-bonded part, and the part to be heated by the glass tube is only a narrow surface with a flat cross section. Residual strain is less likely to remain on the surrounding wall surface blown away by, and the occurrence of cracks is reduced.

[Brief description of drawings]

1 to 5 show a first embodiment of the present invention, FIG. 1 is a front view showing the constitution of each glass tube, FIG. 2 is a sectional view taken along line II-II in FIG. 3 is a front view of the blown state,
FIG. 4 is a front view of a fused state, FIG. 5 is a sectional view taken along line VV in FIG. 4, and FIG. 6 is a front view showing a second embodiment of the present invention, FIGS. 7 and 8. The drawings are perspective views of the third and fourth embodiments of the present invention, and FIG. 9 is a perspective view showing a defective example. 1, 30, 40 ... Glass tube, 2 ... Discharge path, 3 ... Electrode,
4 ... Exhaust pipe, 6 ... Opening part, 8 ... Connection hole, 9 ... Arc tube.

Claims (3)

[Claims] 1. A method of manufacturing a low-pressure metal vapor discharge lamp, comprising: connecting a plurality of glass tubes each having a flat discharge section to form an arc tube having a discharge path which is bent as a whole. The glass tube has an opening formed by heating and softening a part of the narrow surface having the flat cross-sectional shape to blow the openings, and the openings are made to communicate with each other. A method of manufacturing a low-pressure metal vapor discharge lamp, characterized in that the paths are electrically connected to each other. 2. The communication hole is formed by directly abutting and fusing the openings formed by blowing the narrow surface of each glass tube. A method of manufacturing a low-pressure metal vapor discharge lamp according to the item. 3. Each of the glass tubes has a discharge path having a flat cross section formed in a substantially U shape in advance. By connecting the glass tubes with each other in a narrow plane, a meandering shape is formed as a whole. A method of manufacturing a low-pressure metal vapor discharge lamp according to claim 1 or 2, wherein a discharge path is formed.