JP2004063244A - Manufacturing method of fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a manufacturing method of a fluorescent lamp in which the generation of floating type glass wool or the like is prevented and strength of a bridge coupling part can be improved. <P>SOLUTION: A bridge coupling planned portion 7 of glass tubes 3, 4 is softened by heating and hot air of an inert gas is let flow in the glass tubes 3, 4, and by blowing off and breaking the softened bridge coupling planned portion 7 by pressurizing from the inside of the glass tubes 3, 4, the blown off and broken part 9 is formed. This blown off and broken part 9 and a blown off and broken part 9 formed on the other glass tube 4 to be coupled to the glass tube 3 are mutually fusion bonded, and the bridge coupling part 5 is formed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a fluorescent lamp.
[0002]
[Prior art]
Conventionally, as a method of manufacturing a fluorescent lamp in which adjacent glass tubes are bridge-connected to form one arc tube, for example, a portion to be connected between adjacent glass tubes is heated and softened from the outside with a burner and introduced into the glass tube. A method is known in which the softened portion is blown off by gas to form a collar, and the collar is fused to a collar formed on the other glass tube (Japanese Patent Laid-Open No. 55-133730).
[0003]
[Problems to be solved by the invention]
Although such conventional bridge connecting means is generally employed with good productivity, it has been found that the strength of the bridge connecting portion is insufficient. That is, as a result of examining a fluorescent lamp in which the strength of the bridge-connected portion is insufficient, when forming the bridge-connected portion, a large number of fine floating glass cotton in the form of a thread, a film, or a balloon is generated. It was found that it was present in the bridge connection part, and it was found that the presence of such impurities reduced the strength of the bridge connection part. Also, before the glass tube is blown out, a phenomenon occurs in which the glass expands like a balloon at the stage before the glass tube is blown. It has been found that those which are welded without being broken and do not form a discharge path between the electrodes are formed. And it turned out that the intensity | strength of a bridge connection part falls because such a thin part exists. In addition, the presence of such floating glass cotton and thin parts, and those that have been fused without being blown out cannot be confirmed with the naked eye, so they are often found by testing after completion, etc. It was.
[0004]
The present invention has been made to solve such a problem, and an object of the present invention is to provide a method of manufacturing a fluorescent lamp capable of preventing the occurrence of floating glass wool and improving the strength of a bridge connection portion. It is assumed that.
[0005]
[Means for Solving the Problems]
The method for manufacturing a fluorescent lamp according to the present invention is a method for manufacturing a fluorescent lamp in which a plurality of glass tubes are bridge-connected to form a single arc tube. The hot air of an inert gas flows into the glass tube, and the softened bridge connecting portion is pressurized and blown from the inside of the glass tube to form a blown portion, and the blown portion, the glass tube and It has a configuration in which a blow-off portion formed on the other glass tube to be connected is fused together to form a bridge connection portion.
[0006]
Thereby, since the inert gas which comes into contact with the inner surface of the glass tube at the portion where the bridge is to be heated and softened has a warm atmosphere, the smoothness is maintained without causing a sense of temperature discomfort on the glass surface, and the required dimensions are maintained. A blow-off portion having a diameter and a length is formed, and an effect of suppressing the generation of fine floating glass wool can be exhibited. In particular, since the continuous flow of the hot air exerts a strain-relieving annealing action after the formation of the bridge connection portion, there is an advantage that the action of preventing the generation of fine floating glass cotton and the action of preventing the occurrence of cracks due to residual strain are provided.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a fluorescent lamp obtained by a method for manufacturing a fluorescent lamp according to one embodiment of the present invention.
[0008]
In the fluorescent lamp shown in FIG. 1, two glass tubes 3 and 4 in which one end is closed and a stem 2 having an electrode 1 is sealed at the other end are connected by a bridge connecting portion 5 to be integrated. The glass tube 3 and the other glass tube 4 have an internal space connected by a bridge connecting portion 5, thereby forming one discharge path between the electrodes 1. Three-wavelength region phosphors 3a, 4a (see FIG. 4) are adhered to the inner surfaces of the glass tubes 3, 4, and a gas such as argon is sealed therein. Then, there is a configuration in which there is no floating matter, for example, floating glass wool 11 or film-like glass film 11a, which is adhered to the inner surface of the bridge connecting portion 5 shown in FIG. I have.
[0009]
In the method of manufacturing a fluorescent lamp according to the present embodiment, first, as shown in FIG. 2, a phosphor (not shown) is applied to an inner surface, a glass tube having one end closed and an opening 6 at the other end. 3 is heated and softened from the outside by a gas burner 8, and as shown in FIG. 3, a temperature in the range of 60 to 120 ° C. made of an inert gas such as nitrogen, argon, or the like is placed in the glass tube 3. The wind 10 flows from the opening 6 at an inflow pressure in the range of about 0.2 to 1.1 kgf / cm ² , and pressurizes and blows the glass tube wall of the heated and softened bridge connection scheduled portion 7 to blow out and blow the air. To form The blow-off portion 9 and the blow-off portion (not shown) of the other glass tube 4 formed in the same manner as described above are fused to form a bridge connecting portion 5, and the glass tube 3 and the glass The tube 4 is integrated (FIG. 1). In addition, in order to fuse the blown part 9 of the glass tube 3 and the blown part of the glass tube 4, it is necessary to abut the blown parts when each of the blown parts is in a softened state. Therefore, it is preferable that the glass tubes 3 and 4 are arranged at positions close to each other, and that the blow-off portions 9 are formed almost simultaneously. The contact is preferably performed at a temperature (state) at which fusion is possible. Note that the bridge connection scheduled portion 7 may be heated by the gas burner 8 from the inside. Further, it may be softened by heating with a laser or the like other than the gas burner 8. In the case of using a laser, if a portion to be heated and softened (a portion to be bridged 7) is colored, only the colored portion can be heated and softened, so that the blow-off portion 9 can be formed more accurately.
[0010]
As shown in FIG. 4, the bridge connecting portion 5 in the fluorescent lamp thus formed has no residual distortion of glass, has a uniform thickness, and has a thickness that can withstand vibration and impact during transportation or the like. . In addition, there was no generation or presence of fine dust particles made of glass wool in the vicinity of the inside of the bridge connection part 3, and no swelling phenomenon on the glass inner surface was observed. Further, in the method described in the related art, a phenomenon in which the glass swells like a balloon at a stage before the glass tube is blown has occurred, but such a phenomenon in which the glass swells does not occur. Therefore, a thin portion does not occur in the bridge connecting portion, and the strength of the bridge connecting portion can be improved.
[0011]
Hereinafter, a method for manufacturing a fluorescent lamp according to an embodiment of the present invention will be described.
[0012]
Two single-ended glass tubes, each having a length of about 17 mm and an outer diameter of 6 mm, each of which is made of a soda lime glass tube having a tube length of about 410 mm, a tube outer diameter of 20 mm, and a glass wall thickness of 1.2 mm each having a fluorescent substance adhered to the inner surface thereof, A 36 W compact fluorescent lamp (FPL36) integrated with a 1 mm thick bridge connecting portion was manufactured.
[0013]
First, the bridge connection scheduled portion 7 of the glass tube 3 is heated and softened from the outside by the gas burner 8, and nitrogen gas flows into the glass tube 3 from the opening 6 of the glass tube 3 at an inflow pressure of 0.5 kgf / cm ^2. Then, the blown portion of the glass tube 3 (the portion 7 to be bridged) is blown by the pressure, and abuts the blown portion of the other glass tube 4 formed almost at the same time. Was formed.
[0014]
The temperature of the nitrogen gas, which is the hot air 10 flowing into the glass tube 3, is set at (a) 20 ° C., (b) 30 ° C., (c) 50 ° C., (d) 60 ° C., (e) 100 ° C., F) A fluorescent lamp was manufactured as a prototype by setting each temperature to 120 ° C. and (g) 130 ° C., and the connection strength of each bridge connection portion was checked.
[0015]
As a result, in the prototypes (d), (e), and (f), no fine irregularities, swelling phenomenon, and fine floating glass cotton were observed on the inner surface of the bridge connection part, and the glass wall thickness was about 1 mm and uniform. In the manufacturing process of the compact fluorescent lamp FPL36 after the bridge connection and the lighting test of the final finished lamp, no glass breakage such as cracks occurred.
[0016]
In the prototypes (a), (b), and (c), since the temperature difference between the inner surface of the heated and softened portion of the glass tube and the nitrogen gas in contact with the inner surface was large, as shown in FIG. The generation and adhesion of finely suspended glass cotton (glass powder) 11 due to fine crystallization, large variations in glass thickness, residual strain due to inner surface swelling phenomenon, surface unevenness, etc. occur. As a result, it was found that many cracks, breaks, and the like occurred at the bridge connecting portion, which was not suitable for practical use.
[0017]
In the prototype (g), the formation of the bridge connection was normal as in the case of the prototypes (d), (e), and (f). However, when the strain relief annealing after the formation of the bridge connection was performed, high-temperature nitrogen was used. Since the inflow of gas continues, the time required for strain removal becomes longer due to the gradual decrease in temperature, which is not preferable in terms of productivity.
[0018]
The temperature of the nitrogen gas was 60 ° C., which was the inflow pressure to the glass tube and (A) 0.1kgf / cm ^2, which was ^{(B) 0.2kgf / cm 2,} (C) 1. those with 1 kgf / cm ^2, which was (D) 1.2kgf / cm ^2, for was tried each bridge connection as prototype, prototype (B) (C) forms a normal bridge connecting portion The intensity was also normal.
[0019]
However, in the prototype (A), the pressure of the inflowing nitrogen gas is too weak, so that the blow-off of the heat-softened portion of the glass tube does not progress gradually. Further, as shown in FIG. 6, the glass thickness is as thin as 0.3 mm or less. A balloon-like portion 12 was formed and a normal bridge connection portion could not be formed. Also, the prototype (D) was not practical because the pressure of the nitrogen gas flowing into the glass tube was too strong, causing variations in the diameter and glass thickness near the bridge connecting portion, and also in the connecting strength.
[0020]
Therefore, by setting the inflow pressure of the hot air 10 in the range of 0.2 to 1.1 kgf / cm ² , the time from the heat softening to the blow-off and opening at the bridge connection scheduled portion of the glass tube is reduced, It is possible to suppress the thinning of the glass thickness of the bridge connection portion and to form a bridge connection portion having a uniform glass thickness and no residual distortion. That is, the time required from the start of heating to the blow-off can be shortened, and therefore, the thinning of the glass and the generation of the balloon-like shape can be suppressed.
[0021]
The temperature of the nitrogen gas is in the range of 60 to 120 ° C., the pressure of the hot air flowing into the glass tube is in the range of 0.2 to 1.1 kgf / cm ² , and the gas is flowed in two times. It was also found that if the pressure is set to a higher value at first and then to a lower value, formation of a blown portion of the glass, fusion bonding, uniformization of the hole diameter of the bridge connection portion, and the like are smoothly performed.
[0022]
On the basis of the above results, compact fluorescent lamps of 27 W and 55 W rated by JIS, in which two glass tubes were bridge-connected, FPL27, FPL55 and the like were similarly manufactured, and the bridge connection part was confirmed. As a result, similarly to the above, the nitrogen gas flowing into the glass tube is obtained as hot air in the range of 60 to 120 ° C., and the inflow pressure of the hot air is set in the range of 0.2 to 1.1 kgf / cm ^2. The prototype produced no abnormalities in the inner surface of the glass of the bridge connection part, no variation in wall thickness, no residual strain, and the like, and could eliminate a factor that reduces the connection strength of the bridge connection part.
[0023]
However, when the temperature range of the inert gas and the inflow pressure range are not satisfied, the fine floating glass cotton on the inner wall surface of the bridge connection portion, the inner surface irregularities, the inner surface bulge, the glass thickness is uneven, the balloon shape of the glass thin is thin. Swelling and the like occurred, and cracks and breaks due to residual strain occurred in the bridge connecting portion, and the bridge could not be put to practical use.
[0024]
Further, in the present embodiment, the glass tubes 3 and 4 forming the blow-off section 9 have a thickness of 1.2 mm. However, in the case of 0.7 to 1.3 mm, the hot air in the above temperature range is used. It has been confirmed that the same effect can be obtained even in the case where the inflow pressure is satisfied.
[0025]
【The invention's effect】
As described above, the present invention can provide a method for manufacturing a fluorescent lamp capable of increasing the glass strength of the bridge connecting portion of a compact fluorescent lamp having a bridge connecting portion and obtaining stable quality.
[Brief description of the drawings]
FIG. 1 is a sectional front view showing a fluorescent lamp obtained by a method of manufacturing a fluorescent lamp according to an embodiment of the present invention. FIG. 2 is a view for explaining a method of manufacturing a fluorescent lamp. FIG. 4 is an enlarged cross-sectional front view of a bridge connection portion obtained by the same method of manufacturing a fluorescent lamp. FIG. 5 is a view illustrating a bridge connection portion of a fluorescent lamp recognized as defective. FIG. 6 is an enlarged sectional front view for explaining a bridge connecting portion of a fluorescent lamp which is recognized as being defective.
3, 4 Glass tube 5 Bridge connection part 6 Opening part 7 Bridge connection planned part 9 Blow-off part 10 Hot air

Claims (4)

A method for manufacturing a fluorescent lamp in which a plurality of glass tubes are bridge-connected to form one light emitting tube, wherein a bridge connection scheduled portion of the glass tubes is softened by heating and hot air of an inert gas is blown into the glass tubes. Inflow, the softened bridge connecting portion is pressurized and blown from the inside of the glass tube to form a blown portion, and the blown portion and the other glass tube to be connected to the glass tube are formed. A method for manufacturing a fluorescent lamp, comprising: forming a bridge connection portion by fusing the blown-out portions to each other. The method according to claim 1, wherein the hot air is in a temperature range of 60 to 120C. 3. The method according to claim 1, wherein the inert gas is at least one of nitrogen and argon. Fluorescent lamp manufacturing method according to claim 1, the inflow pressure of the hot air, characterized in that the range of 0.2~1.1kgf / cm ^2.

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