JPS6191824A - Method for manufacturing u-shape fluorescent lamp - Google Patents

Abstract

PURPOSE:To remove necessity for turn of a valve in application so as to enable high speed application and easy uniformity of fluorescent film thickness by performing application of phosphor suspension to the inner peripheral face and forced drying of the applied liquid by means of a branch pipe in the center of the curved portion of a U-shape valve. CONSTITUTION:A U-shape valve 3 is stood and retained with a curved portion 3c right above and open ends 5a, 5b are closed by plugs 7, 7 of a valve open end opening and closing means 6. In this condition, phosphor suspension 9 is injected from a branch pipe 4 until the valve 3 is filled. At the same time when injection of the suspension 9 is completed, the means 6 is removed to the suspension from the ends 5a, 5b and hot wind is fed from the branch pipe 4 simultaneously with flowing out. As the flowing out speed of this time is constant and flowing out is completed in a short time, the suspension 9 is applied to the inner peripheral face of the valve 3 in a uniform thickness, and forced drying is performed in the same speed in straight pipe portions 3a, 3b and fluorescent film thickness in the straight pipe portions 3a, 3b can be uniformed.

Description

[Detailed Description of the Invention] Cliff 1"J
The present invention relates to a method for forming a fluorescent film on the inner circumferential surface of a letter-shaped bulb.

Conventionally, straight tube and ring-shaped fluorescent lamps have been the mainstream, but recently U-shaped fluorescent lamps have become about half the length of straight tube fluorescent lamps, and ring-shaped fluorescent lamps have become popular. It has been reconsidered due to its advantages such as being able to be made more compact due to its significantly smaller outer diameter compared to the previous one, and is now being widely used in bulb cap type fluorescent lamp devices and the like. The process of forming a phosphor film in this U-shaped fluorescent lamp involves bending a straight tube bulb into a U-shape, and then pouring a phosphor suspension into the U-shaped bulb to suspend the phosphor on the inner peripheral surface of the bulb. It is generally carried out by applying a cloudy liquid, drying it, and then firing it.

As a method for forming a fluorescent film on the inner peripheral surface of this U-shaped bulb,
For example, the following three methods are disclosed in Japanese Unexamined Patent Publication No. 55-124928.

The first method is to hold the U-shaped valve (1) upright with both opening ends facing upward, as shown in Figure 10 (A), and then enter the valve (1) from the Sekiguchi end. Fluorescent suspension (2
) until it is full, then turn the U-shaped bulb (1) upside down as shown in Figure 10 (b) and let the phosphor suspension (2) flow out. It is.

The second method is to use a U-shaped valve (1) as shown in Figure 11.
A method in which the fluorescent suspension (2) is held upright with both open ends facing down, and the phosphor suspension (2) is spouted into the bulb (1) from the open end and flows out from the other open end. It is. In this case, in some cases, the phosphor suspension (2) is simultaneously ejected into the bulb (1) from both openings, and when it becomes full, the ejection is stopped and the liquid flows out from both opening ends. has been done.

The first method mentioned above is to fill the U-shaped bulb with the phosphor suspension and then turn the U-shaped bulb upside down to let it flow out. Although it is easy to apply the phosphor suspension to the inner circumferential surface of the bulb relatively uniformly, the process of inverting the U-shaped bulb is necessary, which slows down the rate of one application of the liquid, resulting in poor mass productivity.

In addition, in the method of box 2 mentioned above, increasing the jetting speed of the phosphor suspension into the U-shaped bulb will increase the speed of one application, but the higher the jetting speed, the more the phosphor will be applied to the inner peripheral surface of the bulb. It became difficult to uniformly apply the suspension, which made it difficult to increase the liquid application speed. Furthermore, it takes a lot of time to naturally dry the phosphor suspension applied to the inner circumferential surface of the U-shaped bulb, so warm air is passed from one open end of the U-shaped bulb to the other. Forced drying is carried out by blowing away the
The work of blowing this hot air into the valve is troublesome, and the temperature of the hot air blown into the valve drops and is applied to the inner peripheral surface of the double-sided pipe section bordering the bent part of the U-shaped valve. There is a problem in that a large difference occurs in the drying speed of the phosphor suspension, which makes it difficult to equalize the thickness of the phosphor film formed by firing after drying.

The present invention was proposed in view of the above-mentioned problems, and uses a branch pipe connected and integrated at the center of the outside of the curved portion of the U-shaped bulb to inject a fluorescent substance onto the inner circumferential surface of the U-shaped bulb. The above problems are solved by applying a suspension and forcing the coating film to dry.

That is, in the present invention, the U-shaped bulb having the above-mentioned branch pipes is held upright with the curved part facing upward, and the bulb is filled with a phosphor suspension from the branch pipes with both opening ends of the bulb closed. Next, open both ends of this U-shaped valve to let the phosphor suspension inside flow out, and then blow warm air into the U-shaped bulb from a branch pipe to close the valve. To provide a method for forcibly drying a phosphor suspension applied to an inner peripheral surface.

, 1ffl According to the above means, it is possible to fill the U-shaped bulb with the phosphor suspension and then drain it without turning the U-shaped bulb upside down. It becomes easier to increase speed and make the coating film uniform. In addition, the branch pipe connected to the bent part of the U-shaped bulb is eventually chipped off and removed, but this branch pipe is used to set the exhaust pipe of the U-shaped bulb and the coldest point when lighting the U-shaped fluorescent lamp. It can be used as a section.

A specific apparatus for carrying out the method of the present invention and its operation will be described below with reference to FIGS. 1 to 4.

First, a U-shaped valve (3) with a branch pipe as shown in FIG. 1 is prepared. This U-shaped valve (3) is made up of two approximately parallel straight pipe parts (3a) and (3b) connected by a curved part (3c), with one tube located at the center of the outside of the curved part (3C). Branch pipe (4)
are connected and integrated. Also, for the U-shaped valve (3), both open ends (5a) (5b
) is prepared. Valve opening end opening/closing means (6) for appropriately closing the The valve opening end opening/closing means (6) is suitably joined to both opening ends of the U-shaped valve (3), for example, so that both opening ends (5a)
It is composed of an elastic stopper (7) (7) that closes the stopper (5b), and a pillar support (8) that fixes the stopper (7) (7) to the upper surface.

Next, to explain the operation, first, the U-shaped valve (3) is held upright with the bent part (3c) directly above, and both openings of the U-shaped valve (3) are held as shown in Fig. 2. End (5a)
(5b) of the valve opening end opening/closing means (6) (7) (
Close with 7). In this state, the phosphor suspension (9) is injected into the bulb (3) from the branch pipe (4) at a liquid injection rate of about 100 cal/sec. 9
) is full, stop the liquid injection. Next, as soon as the liquid injection is completed, as shown in Fig. 3, both opening ends (5a) of the valve are opened.
Remove the bulb opening end opening/closing means (6) from (5b) to open the opening ends (5a) (51)), and transfer the phosphor suspension (9) in the bulb (3) to both opening ends (5a). ) (5b)
At the same time, hot air (1
0) is sent. Since the liquid outflow speed at this time is almost constant and is carried out in a short period of time, the phosphor suspension (9) is coated on the inner circumferential surface of the bulb (3) with an approximately uniform thickness as in the method shown in Fig. 10. applied. The liquid application speed from liquid injection to liquid outflow can be approximately 10 times faster than the method shown in FIG.

By sending hot air, the hot air (10) passes through the valve (3).
) is divided into two parts from the curved part (3c) and both straight pipe parts (3a
) (3b) and is discharged to the outside from the opening ends (5a) (5b), during which time the phosphor suspension (9°) applied to the inner peripheral surface of the bulb (3) is forced to dry. . Since this drying is carried out at substantially the same speed in both the straight pipe parts (3a) and (3b), it is possible to make the thickness of the fluorescent film uniform in both the straight pipe parts (3a and 3b).

FIG. 5 shows a modification of the valve opening end opening/closing means (6), which is a modification of the valve opening end opening/closing means (6).
a) Provide liquid and air passages (12) (12) that fit the open ends (5a) (5b) in the block (11), which is appropriately attached to (5b), so that a part of the passages (12) (12) On-off valves (13) (13) are provided to open and close the passages (12) (12>) as appropriate.

The valve opening end opening/closing means (6”) shown in Fig. 5 is the opening/closing valve (
13) Close the passage (12) (12) with (13) and attach it to the U-shaped valve (3).
) is injected with the desired liquid, and when it is full, the on-off valve (1
3) (13) opens at the chain line position in Figure 5 and opens the passage (1).
2) (12) opens, liquid flows out, and then warm air (
10) Drying is performed.

After the fluorescent film is formed as described above, the U-shaped bulb (3) is sent to a subsequent process such as a stem sealing process, and the branch pipe (
4) is chipped off at the root and removed. by the way,
This branch pipe (4) has the following utility value.

For example, the branch pipe (4) is used as an exhaust pipe for the U-shaped valve (3). In this case, as shown in Figure 6, electrodes (14) are connected to both open ends (5a) and (5b) of the U-shaped bulb (3).
(14) After sealing the stem (15) (15), the branch pipe (4) is used for evacuation and necessary gas filling, and finally the branch pipe (4) is shown in Fig. 7. Tip off as shown.

Note that the branch pipe (4) is tipped off first and the U-shaped valve (3
) can be finished by sealing the stem with exhaust pipe.

A U-shaped fluorescent lamp made in the manner described above has a variety of uses, two sides of which are shown in FIGS. 8 and 9. Figure 8 shows a U-shaped fluorescent lamp device (18) with a socket (17) fixed to both ends of the U-shaped fluorescent lamp (16), and Figure 9 shows a U-shaped fluorescent lamp (16) with a spherical shade ( 19) shows the bulb cap type fluorescent lamp device (20) housed in the interior of the device. These two fluorescent lamp devices (1B) (20) are connected to the U-shaped fluorescent lamp (1B) (20).
6) When used with the curved part facing down, a U-shaped fluorescent lamp (
The protrusion (m) at the base of the tipped-off branch pipe in the center of the dividing part of 16) is directly below, and this becomes the coldest point of the tube wall temperature when the lamp is lit, and the protrusion (m) Excess mercury in the bulb condenses inside the bulb, and the mercury vapor pressure is controlled so that the light output approaches its maximum value. However, in the fluorescent lamp device (20) shown in Fig. 9, a ventilation hole (19) is provided directly below the shade (19) in order to make the projection (m) the coldest point.
”) is necessary.

By applying a phosphor suspension to the inner circumferential surface of the bulb using a branch pipe at the center of the defining part of the U-shaped bulb as in the present invention, and forcing drying of the coating solution, as in the present invention, There is no need to reverse the valve during liquid application, which speeds up liquid application, and the coating liquid can be dried in the double-sided tubes of the U-shaped bulb under the same conditions, making it easier to make the thickness of the fluorescent film uniform. . Furthermore, the branch pipes of the U-shaped valve can be used for things such as exhaust pipes and determining the coldest point when lighting lamps, which has great added value.

[Brief explanation of the drawing]

1 to 4 are schematic front views of a specific implementation device for explaining the present invention in detail during each operation, and FIG. 5 is a schematic front view showing an example of the implementation device of the method of the present invention. , 6th
Fig. 7 and Fig. 7 are front views of pulp showing an example of production after drying by the method of the present invention, Fig. 8 and Fig. 9 are two sides of a lighting device using a U-shaped fluorescent lamp obtained by the method of the present invention. FIG. FIGS. 10(a) and 11(b) are front views of pulp for explaining two sides of the conventional U-shaped fluorescent lamp manufacturing method. (3) - U-shaped pulp, (3c) - bend, (41 - branch pipe, (5a) (5bL - open end), (9) - phosphor suspension, (10) - warm air. Octopus Pilgrimage N5I1 I's@1 611th 711th r(2) 11th-

Claims (1)

[Claims] (1) A U-shaped valve with a branch pipe connected to the outside center of the bent part is held upright with the bent part facing up and both opening ends closed, and the U-shaped valve is inserted from the branch pipe. After injecting the phosphor suspension into the tube until it is full, open both opening ends to let the phosphor suspension flow out, and then blow warm air through the branch pipe to blow the phosphor suspension into the U-shaped bulb. 1. A method for manufacturing a U-shaped fluorescent lamp, comprising the step of drying a phosphor suspension applied to a phosphor suspension.