JPH0789468B2 - Manufacturing method of ring-shaped fluorescent lamp - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a ring-shaped fluorescent lamp, and more particularly to a heating method in a straight bulb heating step which is a pretreatment step for straight bulb bending.

BACKGROUND ART The heating and bending process of a straight bulb in the manufacture of an annular fluorescent lamp is generally performed in the following manner. For example, two sets of two straight valves (3) are provided from a predetermined position to the heads (2) (2), which are provided around the turntable (1), which rotates intermittently, two sets each at a regular interval. Supply each.
The straight valve (3) has a fluorescent film formed on the inner peripheral surface and has stems with electrodes attached at both ends, and the exhaust pipe (4) led out from the stem at the upper end is connected to the head (2). In addition, the straight valve (3) is vertically suspended and supported by gripping the gripping concave portion at the upper end with a chuck (not shown), and the two valves are intermittently moved as one set to move the heating furnace. It is sent into the inside of (5) and the two are heated at the same time, and is bent when it leaves the heating furnace (5). It is effective in terms of mass productivity and energy saving to heat-bend two straight valves (3) as one set, and the two array pitches m of one set are small, for example, set to about 180 mm. It is set to be smaller than the array pitch between the other two adjacent straight valves. In the oven (5) heating position within the example 7 position P ₃ to P _9, 10 position P ₁₀ is the position closest to the song formed processed into the outlet of the heating furnace (5).
Of the _{3rd to} 9th positions P _{3 to} P ₉ , the 9th position P ₉ may be an electric furnace and the other may be a gas furnace using a burner, but in order to enhance the energy saving effect, the _{3rd to} 9th positions are used.
Position P ₃ to P continued along connexion Description ₉ all this latter scheme below it is desirable to heating using the burner.

Furnace (5) is in the third to ninth position P ₃ cotton for all to P ₉ connexion Figure 3 or a plurality of burners as illustrated in FIG. 5 (6) (6) ... are each position Two parallel valves (3) and (3) in P _{3 to} P ₉ are arranged on the inside and outside of the two parallel valves (3) and (3). Has been installed. If the two inner burner rows at one position are (7a) and (7b) and the outer two burner rows are (8a) and (8b), the two straight valves ( 3) One of the (3) is located in the middle of the burner rows (7a) and (8a), and the other one is located in the middle of the burner rows (7b) and (8b), and each is in the respective burner row (7a). The burner flames from (8a), (7b) and (8b) simultaneously heat the inner and outer surfaces. 2 straight valves (3)
(3) is the first position while the internal pressure is controlled
Is heated stepwise from P _3, and sent to the 10 position P ₁₀ is heated to above the valve softening point in the ninth position P _9.

At the bottom of the tenth position P ₁₀ 2 two mounting pins (1
0) (10) and curved roller (11) (11) of two-division structure are arranged, and the straight valve (3) (3) is provided at the 10th position P _10.
When it comes over, first mount pin (10) as shown in Fig. 6.
(10) rises and is fitted into the lower end of the straight balts (3) (3) to position the straight balts (3) (3). The upper end surface of the mount pins (10) (10) is, for example, a conical surface, so that a slight displacement of the straight palves (3) (3) is corrected. Next, the curved roller (11) (1
1) is overlapped, and the gripping recess at the lower end of the straight valve (3) (3) is supported by a chuck, and as it is shown in FIG. 7, it rotates along the straight valve (3) (3). While rising, the straight valves (3) and (3) are bent into an annular shape.

By the way, two sets of straight valves (3) and (3) that are close to each other in this way are connected to two sets of parallel burner rows (7a) and (7b),
If the burners (6), (6) ... of (8a) and (8b) are heated at the same time, the pitch m of the two straight valves (3) and (3) is small. The height of the two straight valves (3) and (3) is higher than the opposite side, and the lower part of the two straight valves (3) and (3) is in the shape of a figure as opposed to the valve advancing direction and the opposite direction as shown by the two-dot chain line in FIG. I got it. The warp of the straight valve (3) (3) Many occur in the lower little rather than the top, also filed a tendency to warp appears even more conspicuously in the eighth position P ₈ or 9 position P ₉ heating temperature is high It was Such Jikajo valve (3) (3) of the bow-mounted pin of the 10-position P ₁₀ if small (1
It is corrected by 0) (10), but when it gets a little larger, the mount pins (10) (10) do not enter the lower end of the straight valve (3) (3) and the lower end is damaged, or the bending roller (11) ) (11) check becomes inaccurate and cannot be composed,
At the time of bending, the shoulders of the bending rollers (11) (11) may ride on the straight valves (3) (3) to make defective bending products. Actually, the defective product occurrence rate of valve bending products due to occurrence of straight valve warpage during heating is as high as 4 to 5%, and improvement measures have been demanded.

DISCLOSURE OF THE INVENTION The present invention meets the above-described demands, and improves the arrangement of burners for heating a straight valve having two vertically suspended and supported so as to prevent warpage during heating of the straight valve. A method for manufacturing a ring-shaped fluorescent lamp is provided.

According to the present invention, a plurality of straight valves are arranged on the movement locus as two sets, and the plurality of sets are arranged at equal intervals. Vertically suspended so as to be smaller than the interval between the straight valves, and a plurality of burners arranged corresponding to the straight valves on both sides of the moving path before bending the pair of straight valves. In the method for manufacturing a ring-shaped fluorescent lamp in which two straight bulbs are heated at the same time, the plurality of burners are arranged in a C-shape that expands outward from the upper part to the lower part. A method for manufacturing a ring-shaped fluorescent lamp, comprising the steps of:
This is a heating method in which heating is performed simultaneously by each burner in a burner row that spreads in an eight-shape from the top to the bottom of each straight valve in a plane parallel to the straight valves of the book. According to this heating method, the lower the distance between the two straight valves is from the burner row, the lower the temperature rise rate is and the lower the warp of the straight valves is suppressed. Therefore, the conventional problems can be solved easily.

BEST MODE FOR CARRYING OUT THE INVENTION An example in which the present invention is applied to a heating process of a straight bulb (3) in manufacturing the above-mentioned ring-shaped fluorescent lamp will be described with reference to FIGS. Burner (6) (6) ...
The arrangement of, for example, 8th position P ₈ and 9th position P ₉
Change to the following only for other _{3rd to} 7th positions P ₃
~ P ₇ are arranged in parallel in two rows as in the conventional case. Straight valve (3) that has moved to the 7th position P _{7 as} a pair (2)
(3) is preheated to near the softening point, and at this stage the warpage due to heating is very small at all, which is the eighth and ninth.
When heated above the softening point at positions P ₈ and P ₉ , a large amount of warpage occurs, so the burner arrangement at both positions P ₈ and P ₉ is made into an eight-character shape. That is, the two inner burner rows with respect to the burner traveling direction at the eighth position P ₈ are (12a) and (12b), and the outer two burner rows are (13a).
a) and (13b), the inner row of burners (12a) (12b)
As shown in FIG. 9, the lower burner (6) is formed into an eight-character shape in which the upper space is aligned with the arrangement pitch m of the two straight burners (3) and (3) and the space is widened toward the lower part.
(6) ... The outer side surface is heated from the center of the straight valve (3) (3). Burner row (12
a) Since the burner advancing direction side of (12b) is closer to the outlet of the heating furnace (5) than the opposite side and is easily air-cooled, the inclination angle θ _{1 with} respect to the vertical line of the burner row (12a) on the burner advancing direction side is opposite. Set it larger than the inclination angle θ ₂ of the burner row (12b). The outer two burner rows (13a) and (13b) have the same eight-character array that faces the inner burner rows (12a) and (12b) in parallel, and a description thereof will be omitted.

Set the inner burner row at the 9th position P ₉ (14a),
(14b), the outer row of burners (15a), (15b) to the respective row of burners in the same manner as the eighth position P ₈ (14a) (14
Make b), (15a) and (15b) into an eight-letter shape. However, the 9th position P ₉ is a straight valve (3) from the 8th position P ₈
Since (3) is heated to a higher temperature and is closer to the outlet of the heating furnace (5), the inclinations θ ₃ of the burner rows (14a) and (15a) on the burner advancing direction side are larger than θ ₁ , and other burner rows are inclined. (14b),
The inclination angle θ ₄ of (15b) is set larger than θ ₂ .

Two straight valves (3) (3) by the above burner arrangement
Simultaneously heating, the straight valve (3) (3) increases the temperature rise rate of the two opposite side surfaces (3) '(3)' from the upper side to the lower side of the opposite side surface (3) "(3)". It is heated to gradually lower than the rate. Both sides (3) '
(3) ', (3) "(3)" difference in temperature rise rate and two straight valves (3) (3) (3) (3) By determining the inclination angles θ _{1 to} θ ₄ so that the influences on 3) are canceled by each other, the straight valves (3) and (3) almost never warp, and even if warping occurs, the next bending It is so small that there is no problem in processing.

The inclination angles θ ₁ to θ ₄ are θ ₁ = 0.5 to 2.4 ° and θ ₂ = 0.2 to 1.6.
, Θ ₃ = 0.6 to 3.0 °, θ ₄ = 0.5 to 2.4 °, more desirable ranges are θ ₁ = 0.5 to 1.2 °, θ ₂ = 0.2 to 0.8 °, θ
It was experimentally found that ₃ = 0.6 to 1.5 ° and θ ₄ = 0.5 to 1.2 °. Further, according to the experimental results in this latter range, the defective product occurrence rate of the valve bending product was 0.2 to less than 0.3%, demonstrating the remarkable effectiveness of the present invention.

The embodiment of the present invention is not limited to the above example, but the burner arrangement at all heating positions in the heating furnace may be arranged in an eight-character arrangement so that the inclination angle increases toward the rear stage position.

[Brief description of drawings]

1 and 2 are a schematic plan view and a front view for explaining a general heating bending process of a straight valve, and FIG. 3 is a sectional view taken along the line AA in FIG. The drawing is a sectional view taken along the line BB in FIG. 3, FIG. 5 is a sectional view taken along the line CC in FIG. 4,
6 and 7 are side views for explaining the operation in the straight valve bending step, and FIGS. 8 and 9 are partial front views and D- in the straight valve heating step for explaining the present invention.
It is sectional drawing which follows the D line. (3) …… Direct valve, (6) …… Burner, P _{3 to} P ₉ ……
Heating position.

Claims (1)

[Claims] 1. A plurality of straight valves are arranged on a movement locus as a set of two at a regular interval, and the straight valves of one set are arranged at intervals of the other two adjacent ones. Suspended vertically so as to be smaller than the distance between the straight valves of a set, and arranged corresponding to the straight valves on both sides of the moving path before bending processing of a pair of straight valves. In a method for manufacturing a ring-shaped fluorescent lamp in which a pair of straight bulbs are simultaneously heated by a plurality of burners, the plurality of burners are arranged in a V-shape array that spreads outward from an upper portion to a lower portion. A method for manufacturing a ring-shaped fluorescent lamp having a feature.