JPS59215632A - Manufacture of circular fluorescent lamp - Google Patents

Abstract

PURPOSE:To prevent deformation of a stem mount by cooling the stem mount section in a furnace in the bending process of a circular fluorescent lamp. CONSTITUTION:An encapsulated tube 7 is fixed to be suspended by a work head at the position C of a bending system. Through continual counter-clockwise rotation of said work head, said tube 7 is heated above the softening point as it passes through a furnance 11, and upon reaching to the positions F and G the lower stem mount section will face against a cooling air blow nozzle 14 to be cooled by cooling air. The timing for blowing the cooling air is controlled by a solenoid valve 15. Upon reaching to the position D, it is bent into a circle by means of a conventional bending roller 12.

Description

[Detailed description of the invention] This invention relates to a method of manufacturing an annular fluorescent lamp.

In particular, it relates to the bending process for valve pipes using soda nochorus.

As shown in Fig. 1, the annular fluorescent lamp has a flare il+ consisting of a crow and an exhaust pipe (81 and lead wire +2); c-
A pair of stem mount H41% straight valve pipes (2) are pierced and the filament (3) is connected to this lead wire (2).
5) At the same time as sealing both ends of the valve g (5), a step of obtaining a control tube (7) having four gripping parts (61) formed on the outer periphery of both ends of the valve g (5), as shown in FIG. Exhaust pipe (8)
After going through the process of bending the valve pipe and cutting the sealing pipe (7) and the lower exhaust pipe (8) into short pieces, the valve pipe is heated and softened in the bending process (9), and then bent into an annular shape. can get.

Figure 3 shows this bending process, where (a) shows the bending device in plan view, (b) shows the A-A cross section, (
C) shows the B-B cross section of the 5-sealed tube (7)
is the position of C of this bending device.

The four gripping parts (6) at the upper end are attached to the work head (9) so that the holder 0 is chucked and suspended. At the same time, the exhaust pipe (8) exhausts the inside of the stop pipe (7).
For this purpose, it is connected to one working head (9). By intermittent rotation of the working head (9) counterclockwise, the sealing tube (7) passes through the heating furnace Qlli, during which time it is heated above its softening point. Next, the sealing tube (7) that has reached the position D is held in the gripping recess (
6) is chucked and bent into an annular shape by the vertical movement of the bending roller a'A. still.

This bending roller (12) is divided into two parts as shown in Figure (a), and has a structure that opens left and right after bending the sealing tube (7). Also, the upper exhaust pipe (8) The reason for the bending is to prevent the lower part of the sealing pipe from coming into contact with the exhaust pipe during this bending process.
Lead glass was used for 1) and valve pipe (5) due to its ease of processing, but recently there has been a trend to use soda glass for valve pipes due to the need to reduce manufacturing costs. A bottleneck arose as described in . In other words, lead glass has a softening point of around 615°C, but soda glass has a softening point of around 705°C, so it is necessary to raise the temperature of the valve tube in the heating furnace, and the temperature inside the heating furnace is higher than that of lead glass. If the temperature is not higher than 70 to 90 degrees Celsius, the bend cannot be processed properly.And under the temperature condition of 70 to 90 degrees Celsius, the temperature of the stem mount sealed at the end of the valve pipe is also required. As a result of the above rise, a defect occurred in which the stem mount was deformed as shown in Fig. 4.This was because when the valve pipe (5) was heated in the heating furnace, the stem mount (4) was also heated.

The flare (1) made of lead glass softens and tilts due to the weight of the stem mount itself, and this filament (3) comes into contact with the inner wall of the valve pipe (5).
The invention of 1°C is a manufacturing method of an annular fluorescent lamp which prevents defects during bending of the annular fluorescent lamp as described above. The purpose of this system is to provide a mini-mini valve that cools the lower stem mount while heating the valve pipe in a heating furnace.

Hereinafter, an embodiment will be described with reference to the drawings. In FIG. 5(a), the sealing tube (7) is attached to the working head so as to be suspended and supported at the position C of the bending operation. By this intermittent rotation of the working head in the anti-clockwise direction, the clay pipe (7) is heated above the softening point as it passes through the heating furnace 01), and when it reaches the positions F, Q, and G, the 5
As shown in Figure (b), the lower stem mount part has a cooling air flow nostle +141 (!: counter-rotation).

Cooled by cooling air. (151ij This is a solenoid valve that controls the output timing of the cooling air.Next, when the position D is reached, the bending roller Q7JI performs the bending process into an annular shape as in the conventional case.

A 30 watt annular fluorescent lamp with a stem mount made from a bulb made of soda glass with a softening point of 705°C and a flare tube made of lead glass with a softening point of 615°C.
A test was conducted to confirm the effect of blowing cooling air in a heating furnace using a J clay pipe. As a result, the stem mount is cooled by cooling air flow from the position where the temperature of the valve pipe exceeds 720°C to position 1 just before it is bent into an annular shape.

It was confirmed that there were no defects such as deformation of the stem mount. Incidentally, by making the air blow flow only while the working head 9 is moving and the sealing tube is stationary, it is possible to suppress a drop in the temperature inside the heating furnace.

In addition, to prevent the stem mount from cooling rapidly and causing cracks, we adjusted the air flow rate and flow rate.

As explained above, according to one aspect of the present invention, an annular fluorescent lamp is heated in a heating furnace during a bending process.

By cooling the steno mount part, it is possible to prevent the stem mount from becoming deformed by suppressing the temperature rise in the stem mount part. You can get the future.

[Brief explanation of drawings]

Figures 1 and 2 show a sealed tube of an annular 1st't->°t lamp. Figure 1 is a partial sectional view, Figure 2 is a front view showing the state immediately before bending, and Figure 3 ( a) to (C) are diagrams for explaining the bending process, and FIG. 4 is a partial sectional view showing deformation of the stem mount. (a) is a plan view showing the configuration of the power oI equipment, and (b) is a sectional view taken along line E-E in (a). In the figure, (4) is the stem mount, (5) is the system. Valve pipe r
Qtl is a heating furnace. In each figure, the same numbers indicate corresponding parts. Agent Masu Oiwa in Figure 1 Figure 21 ¥1 Figure 3 (2) (Plan)

Claims (1)

[Claims] A straight valve pipe with stem mounts fixed at both ends is suspended vertically, and when the valve pipe is heated in a heating furnace to above its softening point and bent into an annular shape, a cooling air blow is applied to the stem mount part. A current method of manufacturing a firefly lamp, characterized in that the bulb tube is heated from the base.