JP3101658B2 - Manufacturing method of stem for tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing various types of tube stems, such as fluorescent lamps and electric bulbs, and more particularly to a method for detecting and removing morphological defects of a sealing portion generated in the process of manufacturing the stem.

[0002]

2. Description of the Related Art As shown in FIGS. 1 and 2, a stem 1 for a tube such as a fluorescent lamp or a light bulb is provided with a pair of flared glass 2 having one end flared at the inner end. Electrode lead
A structure is adopted in which the exhaust lines 4 are implanted outside the flared glass 2 whose diameter has been increased while sealing with a pinch seal. Tube stem 1 of this shape
Although not shown, an electrode filament is attached to the inner ends of the pair of electrode lead wires 3 and 3, and a glass bulb of a bulb is sealed to the outer end of the expanded flared glass 2. The inside is evacuated and used for manufacturing a bulb.

[0003] By the way, a tube stem 1 having such a structure.
Is, for example, as shown in FIG. Material supply, b. First heating, c. First molding, d. Second heating, e. Second molding,
f. Third heating, g. Third molding, h. Cooling, i. Distortion removal,
j. Cooling, k. It is manufactured by an automatic stem machine having a process such as removal. That is, the flare glass 2 in which the pair of electrode lead wires 3 and 3 and the exhaust pipe 4 are arranged in a standing state inside by the material supply of a, and the flare glass 2 by the first heating of b
Are heated and melted by the burners arranged on both sides of the flared glass 2, and the sealing portion 5 on the inner end side of the flared glass 2 is crushed by a pincher in the first molding of c, thereby forming the general shape of the stem 1. Next, it is heated and melted again by the second heating of d, and the sealing portion 5 is formed by the second molding of e.
Is completely pinch-sealed, and if necessary, heating and forming of f to g are repeated, and the sealing portion 5 is formed into a predetermined shape so that the electrode lead wire 3 is finally tightly sealed. I do. In the manufacture of the tube stem 1 on the exhaust side of the tube,
During the second heating of d or the third heating of f, air blow is performed from the upper side of the exhaust pipe 4 implanted, and the flare glass 2 is blown.
And the exhaust hole 6 is opened. The tube stem 1 thus formed is completed through steps such as cooling with the air blower h, removing strain i, and final cooling j.

[0004]

However, the tube stem 1 which is automatically manufactured in this way is not suitable because of insufficient burning of the flare glass 2 by a burner or glass breakage during the manufacturing process of the stem 1. In addition, various morphological defects may occur. For example, as shown in FIG. 4, due to insufficient burning of the flare glass 2 or deterioration of air-blowing conditions, the opening of the exhaust hole 6 becomes insufficient, and the exhaust hole 6 is not provided or becomes extremely small. I do. Further, as shown in FIG. 5, the sealing portion 5 is shouldered and the thickness is uneven due to the glass breakage of the flare glass 2. If such a poor shape of the stem is sealed to the bulb valve as it is, the former will result in poor exhaust of the bulb, and the latter will cause a glass crack in the sealed part,
This was the main cause of lowering the tube production yield. For this reason, in the past, morphological defects in the manufacture of such tube stems were mainly removed visually by the operator, but it was considered difficult to completely remove them, and automation and labor saving could not be performed. .

Accordingly, the present invention has been made in view of the above-described method of selecting and removing the defective shape of the tube stem, and detects and removes the defective shape of the tube stem without visual inspection of an operator. An object of the present invention is to provide a method for manufacturing a stem for a tube.

[0006]

For this reason, the present inventors have made intensive studies and as a result, in the cooling process during the production of the tube stem, the temperature of the stem sealing portion is reduced by the shape of the tube stem. It was found that there was a great difference between the normal one and the poorly formed one. That is, according to the study results of the present inventors, the temperature difference of the stem sealing portion in the stem cooling step depending on the presence or absence of the exhaust hole is 80% less in the case of the holeless product than in the case of the normal stem.
It was found that the temperature of the stem became higher by about 50 ° C. and that the thickness of the stem sealing portion became uneven and the shoulder became higher than the normal stem by about 50 ° C. Therefore, the present invention
In the manufacturing process of the tube stem, the temperature of the stem sealing portion is detected by a temperature sensor, and the quality of the shape of the tube stem is determined based on the detected temperature.

[0007]

The sealing portion of the stem glass is relatively thick and has a heat capacity. In a cooling process of manufacturing a stem having a substantially completed morphological structure, a normal stem shape and a poor stem shape are obtained.
As described above, a large temperature difference occurs in the sealing portion temperature. Therefore, the temperature of the stem sealing portion is detected by the temperature sensor, and a temperature equal to or higher than a predetermined temperature can be determined as a defective configuration,
It can be automated without human visual inspection.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 6 is an explanatory diagram of a detection state of a morphological defect of the tube stem 1 used in the fluorescent lamp according to the embodiment of the present invention.
The temperature sensor 7 is provided in, for example, the cooling step h or j of the automatic stem machine shown in FIG. That is, the temperature sensor 7 is an infrared temperature sensor that is not in contact with the tube stem 1 to be measured, and is disposed at a position facing the stem sealing portion 5.

Table 1 shows the observation results of the temperature of the stem sealing portion 5 when the hole diameter of the exhaust hole 6 of the stem 1 with the exhaust pipe hole according to the present invention is changed. Sample # 1 having a normal hole diameter has no hole. About 80 ° C. higher than that of sample # 2. Therefore, a temperature slightly higher than the temperature of the stem sealing portion 5 observed in the sample # 1 having a normal pore diameter, for example, 480 ° C., is set as the reference temperature, and a higher observation value is rejected as a holeless defect. do it.

[0010]

[Table 1] Sample exhaust pipe hole diameter Observation temperature # 1 3-4mm (normal) 440-450 ° C # 20-1mm (no hole) 520-530 ° C

As shown in FIG. 5, Table 2 shows the results of observation of the stem 1 in which the sealing portion 5 was shouldered and the thickness of the stem 1 was deviated due to glass breakage and the like. Sample No. 3 is about 50 ° C. higher than Sample # 4 with uneven thickness. Therefore, a temperature slightly higher than the temperature of the stem sealing portion 5 observed in the normal-shaped sample # 3, for example, 510 ° C., is set as the reference temperature, and a higher observed value is regarded as a morphological defect and is rejected. .

[0012]

[Table 2] Sample sealing part shape Observation temperature # 3 Normal product 480-500 ° C # 4 Shoulder item 530-550 ° C

[0013]

As described above, according to the present invention, the temperature of the stem sealing portion is detected by the temperature sensor in the cooling process during the production of the stem, and the temperature of the stem sealing portion is removed to remove the temperature above the predetermined temperature. Poor morphological defects, such as tubeless defects and shoulder drop, can be effectively rejected. In addition, conventionally, the morphological defects of these stems have been relied on visual inspection by an operator, but can be mechanized, and the effects of automation and labor saving are great.

[Brief description of the drawings]

FIG. 1 is a front view of a tube stem to which the present invention is applied.

FIG. 2 is a side view of the tube stem of FIG. 1;

FIG. 3 is a front view of an automatic stem machine for manufacturing a tube stem to which the present invention is applied.

FIG. 4 is a front view showing an example of a defective shape of the tube stem.

FIG. 5 is a front view showing an example of a defective shape of the tube stem.

FIG. 6 is a side view showing a configuration of a main part of manufacturing a stem for a tube according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube stem 2 Flare glass 3 Electrode lead wire 4 Exhaust pipe 5 Sealing part 6 Exhaust hole 7 Temperature sensor

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Shinji Amano 1-4-4 Shiromi, Chuo-ku, Osaka-shi, Osaka NEC Home Electronics Co., Ltd. In-house (58) Field surveyed (Int. Cl. ⁷ , DB (Name) H01J 9/42 H01J 9/32 H01K 3/08

Claims (3)

(57) [Claims] In a stem manufacturing process in which an exhaust pipe and a lead wire are arranged in a flare and softened and melted by a burner to seal the lead wire, the temperature of the sealing portion is reduced. A method for manufacturing a stem for a tube, characterized in that the temperature is detected by a temperature sensor, and the defective form of the sealing portion is detected by the detected data. 2. The method for manufacturing a stem for a tube according to claim 1, wherein the morphological defect is a defective hole in a sealing portion of the exhaust pipe. 3. The method for manufacturing a tube stem according to claim 1, wherein the defective shape is defective deformation of the sealing portion due to burning or glass breakage.