JPS58155623A - Manufacture of curved type fluorescent lamp - Google Patents

Abstract

PURPOSE:To surely prevent a prearranged part for curving from deformation or the like by a method wherein the prearranged part, whose partial peripheral surface is flatly formed, is heated and said prearranged part for curving is curved while holding the flatly shaped part of the prearranged part inwardly. CONSTITUTION:When a prearranged part for curving 5 in the axial center of a linear tube-shaped glass bulb 1 is held between molding jigs 6a and 6b, the prearranged part for curving 5 is gradually heated and softened while a peripheral part projected from a molding groove 7 is flatly crushed by a holding surface of the molding jig 6b of the other side to form a flatly shaped part 8 on one peripheral part of the prearranged part for curving. Next, said prearranged part 5 is heated up to the temperature at which curving is made possible, and both sides of said prearranged part for curving 5 are wound up in the direction making both sides to come near each other. Then the prearranged part for curving 5 is made to curve in the U-shape to form a curved part 9 while the winding up is stopped when linear parts 10 and 10 connecting the curved part 9 to both end parts are faced at both sides of said curved part 9. In this way of curving, the linear tube type glass bulb 1 is molded in the almost U-shape wherein both end parts are adjacent each other to complete a curved tube type fluorescent lamp 11.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for manufacturing a curved tube-shaped fluorescent rung; [Technical background of the invention and problems thereof] Conventionally, for example, a U-shaped curved tube shape has been manufactured. One way to manufacture a fluorescent lamp is to coat the inner surface of a straight glass bulb with a phosphor coating, which produces 4K.

The openings at both ends of this glass pulp are firmly attached to the mount, and then the portion of this glass pulp to be bent is heated with a burner, etc., and then the heated and softened portion to be bent is wrapped approximately halfway around the tube forming drum. A method is known in which a lever is bent into a U-shape.

By the way, in this method, a forming drum is used to maintain the circular cross-sectional shape of each part of the forming part during bending, but this forming drum is removed from the bent part of the glass pulp after bending. This results in problems such as the need for this rounding drum to be divided in the thickness direction, which complicates the structure of the relum. Moreover, in order to maintain the circular cross-sectional shape of the curved portion, the heating source FjIL of the portion to be curved must be
It is necessary to control the curved area with high precision and to heat it over a wide area on the area to be curved, which complicates the manufacturing process and also causes a large thermal effect during heating, so the phosphor coating is It has disadvantages such as being susceptible to thermal deterioration and having a negative effect on light efficiency.

[Purpose of the invention]

The method of the present invention was developed based on these circumstances, and its purpose is to reliably prevent deformation of the portion to be bent during bending of glass pulp, and to prevent heating of the portion to be bent. The present invention aims to provide a method for manufacturing a tubular fluorescent lamp, which requires only a narrow range and allows easy temperature control.

[Summary of the invention]

That is, in the present invention, at least a part of the periphery of the portion to be bent of the straight glass pulp is formed into a flat shape, and after heating the portion to be bent, the flat portion of the portion to be bent is bent. The above objective is achieved by curving the portion to be curved on the inside.

[Embodiments of the invention]

The method of the present invention will be explained below based on a first embodiment shown in FIGS. 1 to 3.

First, the phosphor coating 2 is applied to the inner surface of the straight glass pulp 1, and the mounts 3.3t are sealed to the openings at both ends of the glass pulp 1.

After exhausting the inside of the gas pulp 1 through the exhaust pipe 4 of this mount 3.3, fill the required amount of mercury and inert gas through this exhaust pipe 4f, and then seal the exhaust pipe 4 airtight. Stop.

Next, a heater is installed inside each of the forming jigs 6a, gbFi, which are sandwiched from the radial direction by a pair of forming jigs 6m, s, 6b for the axially central bending portion 5f of the straight glass pulp 1. A molding tar having a substantially semicircular cross section into which the glass pulp 1 is inserted is provided on the clamping surface of one of the molding jigs 6a. Therefore, when the part to be bent 5 is held between the forming jigs 6m and 4b, the part to be bent 5 is gradually heated and softened, and the wind direction portion protruding from forming #I7 is held by the other forming jig 6b. It is crushed into a flat shape by the surface and becomes a flat surface. Therefore, a flat portion 8 is formed on a part of the circumferential surface of the curved portion s5, and the cross-sectional shape in the radial direction becomes approximately semicircular.

Next, when this portion 5 to be bent is heated to a temperature at which it can be bent, both sides of this portion 10 to be bent are rolled up in a direction toward each other, with the flat slt curved on the inside. As a result, the part to be formed 5 is bent into a U-shape to form a bent part, and straight parts 10 and 10 are formed on both sides of this bent part 9 to connect the bent part and both ends. , the straight part 10.
10 is opposed, the above-mentioned winding is stopped. By such bending, the straight glass pulp 1 is formed into a substantially U-shape with both ends adjacent to each other and positioned in the same direction, and a curved fluorescent lamp 11 is completed.

According to the first embodiment, a part of the surface of the part 50 to be formed is crushed into a flat tube shape, and this flat part 8 is bent to the extent that it is planned to be bent. There is no undesirable wrinkles in the schedule.-
The molded shape is maintained perfectly. In other words, since the inner side of the bending portion 1 that receives the force in the compressive direction due to the bending is a flat surface, it appears that an unreasonable force is applied to this inner side of the bend, and as a result, the injury progresses. Even if the curved portion 5 is bent, the cross-sectional shape of the portion 5 will be distorted. Therefore, there is no need for a special forming drum like in the past for bending.
Manufacturing equipment can be simplified. Further, because of this, the straight portions 10 and 10 on both sides of the curved portion 9 can be brought very close to each other, and even if the actual pulp overall length is the same, the entire runde can be made into a continuous four-piece structure.

In this case, by appropriately setting the tube axis length and tube diameter of the pulp 1, it is possible to suppress the overall size to about the same size as a 60 to 100 W class incandescent light bulb). If this run is integrated with a screw-in cap such as the E26 type and circuit parts for lighting and starting such as a lighting tube or ballast, it can be used by screwing into an existing incandescent light bulb socket as is. .

Furthermore, according to this method, the radius of curvature of the bending portion 9 can be reduced, and the heating range of the portion to be bent 5 can be narrowed, in combination with the fact that the forming drum is not required. In particular, when the phosphor coating 2 is applied and bent after death as in the first embodiment, the phosphor coating 2
Therefore, deterioration of the phosphor cover III can be prevented, and a decrease in light efficiency can be suppressed.

Note that the method of the present invention is not limited to the first embodiment described above, and a second embodiment of the method of the present invention is shown in FIGS. 4 to 6.

This second embodiment shows the case where not only the flat part s't * planned to be formed 5 but also 12 continuous parts are provided along the entire length of the glass pulp 10. Condition 5
Since the flat portions 8' and 81 in 10 and 1 eIK are closely opposed and have a good shape, the cross-sectional shape of this portion along the radial direction is as shown in Fig. 6 despite the straight portions 10 and 10 being juxtaposed. As shown in the figure, the tube has a substantially circular shape, and the appearance is upward, and the surrounding layer is approximately even with respect to the tube axis. In other words, in the bending method using a forming drum, the distance between the straight parts 10 and 10 is equal to the diameter of the forming drum, so the illuminance distribution with respect to the tube axis of the straight parts 1o and 1o is approximately cocoon-shaped. However, according to the second embodiment, since the illuminance distribution becomes approximately circular, good results can be obtained in terms of light distribution characteristics.

Further, in each of the above embodiments, the bending portion is provided at one location, but the bending portion may be provided at multiple locations between both ends of the t-bulb. Therefore, the shape of the bent tube-shaped fluorescent rung is also specified to be U-shaped. Not done.

Furthermore, the present invention is not limited to the case where the acid part is formed into a U-shape.

Furthermore, in the above example, the pulp was bent after the sealing of the mount and the application of the phosphor coating were completed, but in contrast to this, the sealing of the mount and the application of the phosphor coating were performed after the pulp was bent. It is good practice to do this.

〔Effect of the invention〕

The present invention described in detail above forms a portion of at least four curved portions of a straight tube-shaped glass pulp into a flat shape, and heats the curved portions. This is a method of manufacturing a curved tube-shaped fluorescent lamp in which a portion to be bent is bent with the flattened portion being bent inside. According to this method, the inner side of the part to be bent, which is subjected to compressive force due to bending, is a flat flat surface, so no excessive force is applied to this inner side, and the cracking progresses. 11 The cross-sectional shape of the part to be bent is less likely to be distorted, and therefore no special jig is required for conventional forming drums, and manufacturing equipment can be simplified. Also, from this, it is possible to reduce the radius of the part to be formed, which allows the entire rung to be made more compact, and the heating range of the part to be grown is narrower than in the conventional method, so when heating It has excellent effects such as easy temperature control.

[Brief explanation of the drawing]

1 to 3 show the first embodiment of the method O of the present invention,
Fig. 1 is a perspective view, Fig. 2 is a sectional view, Fig. 3 is a side view of the lamp, Figs. 4 to 6 show a second embodiment of the method of the present invention, and Fig. 4 is a perspective view; Figure 5 is a view of Lang OS, Figure 6
The figure is a sectional view taken along the fifth middle line MM. 1...Glass pulp, 5...-Planned part, ##"・
... Squamous part, 9... Curved part.

Claims (1)

[Claims] In the method of manufacturing a curved fluorescent lamp ff by forming a straight glass pulp tube, at least a part of the surface of the straight glass pulp in the portion to be bent is formed into a flat shape; 1. A method for manufacturing a curved tube-shaped fluorescent rande, characterized in that after heating the portion, the flat portion of the upper portion to be bent is bent inside and the portion to be bent is bent.