WO2004012224A1

WO2004012224A1 - Bulb type electrodeless fluorescent lamp and method of manufacturing the fluorescent lamp

Info

Publication number: WO2004012224A1
Application number: PCT/JP2003/009519
Authority: WO
Inventors: Akira Hochi; Koichi Katase
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2002-07-30
Filing date: 2003-07-28
Publication date: 2004-02-05
Also published as: JP2006054054A; AU2003252707A1

Abstract

A bulb type electrodeless fluorescent lamp (220), comprising a luminescent tube (100) having luminescent gas sealed therein, an induction coil (30) inserted into the recessed part (24) of the luminescent tube (100), a lighting circuit (40), a case (50) storing the lighting circuit (40), and a ferrule (60), the luminescent tube (100) further comprising a generally spherical outer tube (10) and an inner tube (20), wherein a neck recessed part (14) and a neck projected part (16) are formed at the neck part (13) of the outer tube (10) positioned around a sealed part (12) formed by connecting the outer tube (10) to the inner tube (20) in that order from the sealed part (12) side.

Description

Satsuki Itoda Bulb-shaped electrodeless fluorescent lamps and their manufacturing methods

The present invention relates to a bulb-type electrodeless fluorescent lamp and a method for producing the same. Background art

In recent years, from the perspectives of global environmental protection and economics, bulb-type fluorescent lamps with electrodes, which are approximately five times more efficient than incandescent lamps, have been widely used as substitutes for light bulbs in houses and hotels. Such a bulb-shaped fluorescent lamp having electrodes is disclosed, for example, in Japanese Patent Application Laid-Open No. 2001-196194. The bulb-type fluorescent lamp has a built-in lighting circuit and a base, so it has a structure that can be directly substituted for an incandescent lamp.

Furthermore, recently, electrodeless bulb-type fluorescent lamps have begun to spread in addition to the existing electrode-type bulb-type fluorescent lamps. The feature of electrodeless fluorescent lamps is that they have a longer service life than electrodeed fluorescent lamps because they have no electrodes, and are expected to become more widespread in the future. Such a bulb-type electrodeless fluorescent lamp is disclosed, for example, in US Pat. No. 5,959,405. Figure 7 shows the bulb-type electrodeless fluorescent lamp.

The bulb-shaped electrodeless fluorescent lamp 100 shown in FIG. 7 is a bulb-shaped electrodeless fluorescent lamp that is an alternative to a reflective bulb (reflamp). This lamp 1000 is composed of an arc tube (valve) 110, a case 150 with a reflecting surface 152, and a base 160. An induction coil 130 is inserted into the recess of the arc tube 110. In the case of the lamp for replacement of the reflex lamp 100, most of the external appearance (especially the side) of the arc tube 110 can be covered by the reflective surface 152 attached to the case 150. It is not necessary to pay special attention to the external shape of the arc tube. In other words, since most of the light emitting tube 110 can be covered by the case, it is relatively easy to design a bulb-shaped electrodeless fluorescent lamp having the shape of a glass bulb type R (JISC 7110). is there.

However, in the case of electrodeless fluorescent lamps that can be directly substituted for ordinary incandescent lamps, there is no reflective surface, so most parts of the arc tube need to have the same appearance and dimensions as incandescent lamps. There is. In other words, it is necessary to manufacture the bulb-shaped electrodeless fluorescent lamp in the same manner as the glass bulb type A (JISC 7110), which is widely used as an incandescent bulb shape (so-called eggplant type). Required. The arc tube of an electrodeless fluorescent lamp is often manufactured as a smooth, almost elliptical shape due to the manufacturing method, but it is difficult to resemble an A-shaped incandescent lamp with such a shape. In other words, in the case of a smooth arc tube having a substantially elliptical shape, a gap is often formed between the arc tube and the case, which causes an aesthetic problem. Also, if an arc tube with a shape that does not create a gap with the case is made, the arc tube portion that must be housed in the case becomes too large, and the space for arranging the lighting circuit in the case Is lost. If a lighting circuit is to be arranged, the case must be made even larger. As a result, the shape of the bulb-shaped electrodeless fluorescent lamp differs from the shape of an incandescent lamp, which also causes an aesthetic problem.

The present invention has been made in view of the above points, and a main object thereof is to provide a bulb-type electrodeless fluorescent lamp having the same appearance as an incandescent bulb. Disclosure of the invention

A bulb-type electrodeless fluorescent lamp according to the present invention includes a light emitting tube filled with a luminescent gas and having a recess, an induction coil inserted into the recess, and a lighting circuit electrically connected to the induction coil. A case accommodating the lighting circuit; a base electrically connected to the lighting circuit; and a base attached to the case, wherein the arc tube has a substantially spherical outer tube and an inner portion defining the recess. A neck portion located around a sealing portion formed by joining the outer tube and the inner tube, of the outer tube, in order from the sealing portion, A concave portion and a neck convex portion are formed.

It is preferable that the appearance of the arc tube is substantially a glass sphere type A shape o

It is preferable that the neck protrusion and the upper end of the case are close to or in contact with each other. Good.

It is preferable that the residual stress of the neck projection is 14 MPa or less.

It is preferable that the residual stress in the neck recess is not more than 14 MPa.

It is preferable that a residual stress of the neck portion including the neck convex portion and the neck concave portion is 7 MPa or less.

It is preferable that the residual stress of the entire outer tube in the arc tube is 7 MPa or less.

The method for producing a bulb-type electrodeless fluorescent lamp of the present invention comprises the steps of: (a) preparing an outer tube having a substantially spherical portion at one end and an opening at the other end; and a cylindrical inner tube. (B) setting the inner pipe in the outer pipe, sealing a part of the outer pipe and a part of the inner pipe, and joining the outer pipe and the inner pipe; In the step (b), a step of forming a network concave portion and a neck convex portion in a neck portion located around a sealing portion where the outer tube and the inner tube are joined is performed. After the step (b), a step of reducing the residual stress of the neck projection to 14 MPa or less by heating the neck projection at least.

In one embodiment, the step of reducing the residual stress to 14 MPa or less includes a step of annealing the glass material forming the outer tube at a temperature of an annealing point.

FIG. 1 is a cross-sectional view schematically showing a configuration of an arc tube 100 of a bulb-type electrodeless fluorescent lamp according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing the appearance of the arc tube 100. FIG.

FIG. 3 is a cross-sectional view schematically showing the configuration of the bulb-type electrodeless fluorescent lamp 220 according to the first embodiment.

FIG. 4 is a diagram of the arc tube 100 for explaining the distortion of the neck convex portion 16 and the neck concave portion 14.

FIGS. 5 (a) and 5 (b) are tracings of photographs of strain measurement of the arc tube 100 before and after annealing, respectively.

FIGS. 6A to 6C are views for explaining a manufacturing method according to the second embodiment of the present invention. FIG.

FIG. 7 is a cross-sectional view showing a configuration of a conventional bulb-type electrodeless fluorescent lamp.

FIG. 8 is a chart showing the results of the heat cycle test.

Fig. 9 is a chart showing the difference in strain between cracked and uncracked ones in the heat cycle test.

FIG. 10 is a chart showing the correlation between the strain and the stress in soda glass. Fig. 11 is a chart showing the fatigue parameters of soda glass.

FIG. 12 is a chart showing a change in rupture time due to a decrease in stress. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numeral for simplification of description. Note that the present invention is not limited to the following embodiments.

(Embodiment 1)

A bulb-type electrodeless fluorescent lamp according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 schematically shows a cross-sectional configuration of an arc tube 100 of the bulb-type electrodeless fluorescent lamp of the present embodiment, and FIG. 2 shows an appearance of the arc tube 100.

The arc tube 100 is composed of a substantially spherical outer tube 100 and an inner tube 20 defining a concave portion (cavity) 24. The outer tube 10 and the inner tube 20 are joined by sealing at the sealing portion 12, and the neck portion 13 is located around the sealing portion 12 c. An induction coil is inserted into 4, and a thin exhaust pipe 22 used in the manufacturing process is attached to the upper part of the inner pipe 20. In the completed arc tube 100, one end of the thin tube 22 is connected to the inside of the arc tube, but the other end is sealed, so that the inside of the arc tube has a sealed structure. Further, a phosphor layer is formed on at least a part of the inner wall of the arc tube 100.

As shown in FIGS. 1 and 2, the neck portion 13 is formed with a neck concave portion 14 and a neck convex portion 16 in this order from the sealing portion 12. In the case of the arc tube 100 in which the neck concave portion 14 and the neck convex portion 16 are formed, a smooth substantially elliptical shape is formed. Compared to the arc tube, the lower part of the arc tube 100 (particularly, the part below the neck convex part 16) can be shortened, so that the shape is substantially the same as the glass ball type A shape. As a result, it is possible to realize a bulb-type electrodeless fluorescent lamp that does not impair the aesthetic appearance as compared with the appearance of the incandescent lamp and that secures a space for disposing the lighting circuit in the case. Here, the glass sphere type A is the shape of a glass sphere specified in JISC770, which is a so-called eggplant shape. The neck portion is a portion that narrows from the maximum diameter portion of the arc tube toward the base.

Next, refer to FIG. FIG. 3 schematically shows a cross-sectional configuration of a bulb-shaped electrodeless fluorescent lamp 220 provided with an arc tube 100. In FIG. 3, the cross section of the recessed portion is shown in two stages on the left and right for easy understanding of the structure.

The bulb-type electrodeless fluorescent lamp shown in FIG. 3 has an arc tube 100, an induction coil 30, a lighting circuit 40, a case 50, and a base 60. The arc tube 100 is filled with a light-emitting gas, for example, mercury and a rare gas. An induction coil is inserted into the recess 24 formed in the arc tube 100.

In the present embodiment, the induction coil 30 includes a ferrite core 32 and a winding 34. The induction coil 30 is electrically connected to the lighting circuit 40, and the lighting circuit 40 is housed in the case 50. A base 60 is attached to a lower portion of the case 50, and the base 60 is electrically connected to the lighting circuit 40.

As shown in FIG. 3, the neck concave portion 14 and the neck convex portion 16 are formed in the arc tube 100, so that the neck convex portion 16 and the upper end 50a of the case 50 are close to each other. Or can be contacted. Therefore, the connection point 80 between the arc tube 100 and the case 50 is aesthetically smooth, and there are no large gaps or large steps that impair the aesthetic appearance. In addition, since the connection portion 80 is smooth and the position of the sealing portion 12 of the arc tube 100 is above the case 50, a space for disposing the lighting circuit 40 in the case 50 is provided. It is possible to secure enough. Therefore, it is possible to avoid the problem that the case 50 must be made large so as to impair the aesthetic appearance.

In this embodiment, the shape of the arc tube 100 is substantially a glass sphere type A, and the diameter of the glass sphere (the maximum diameter of the arc tube 100) is, for example, 55 to 75 mm. It is. The length (total length) from the top of the arc tube 100 to the end of the base 60 is, for example, 120 to 65 mm. The base 60 uses E26 / 25. The rated voltage [V] and the rated power consumption [W] are 100 to 240 V and 7 to 22 W, respectively.

If the arc tube 100 shown in FIGS. 1 to 3 is used, it is possible to provide a bulb-type electrodeless fluorescent lamp having the same appearance as an incandescent lamp without impairing the appearance. It was found that as a result of forming the neck concave portion 14 and the neck convex portion 16, the strength and reliability of the neck portion 13 were reduced. The inventor of the present application has considered the problem and started to solve it.

When observing the strain (residual stress) of the arc tube 100, as shown in FIG. 4, compressive strain exists in the region of the neck convex portion 16, while pulling occurs from the neck concave portion 14 to the region of the sealing portion 12. It was found that there was distortion. This is a result of the manufacturing process, and is due to the fact that compressive strain remains in the part that was previously cooled during processing. In other words, since the neck convex portion 16 in a region apart from the sealing portion 12 in which the outer tube 10 and the inner tube 20 are sealed by heating cools first, compressive strain remains there, and the compressive strain is The tensile strain corresponding to the above remains in the region from the neck concave portion 14 to the sealing portion 12. In Fig. 4, the area with the oblique line from the upper right to the lower left is shown as the area where the compressive strain is present, and the area with the oblique line from the upper left to the lower right is where the tensile strain is present. This is shown as a region to be used.

When compression strain and tensile strain are present, cracks usually enter from the tensile strain, and cracks progress along the interface with the compressive strain. As a result, the life of the arc tube 100 is earlier than when there is no distortion. In order to improve the strength and reliability of the arc tube 100, the compressive residual stress at the neck convex portion 16 must be 14 MPa or less (preferably 7 MPa or less, more preferably substantially OMPa (1.4 MPa or less). )) Is desirable. Further, it is desirable that the residual tensile stress in the neck recess 14 is 14 MPa or less (preferably 7 MPa or less, more preferably substantially OMPa (1.4 MPa or less)). Further, it is more desirable that the residual stress of the entire outer tube 10 in the light emitting tube 100 is 7 MPa or less (preferably, substantially OMPa (1.4 MPa or less)). Remove residual stress To remove the arc, a process (annealing) of heating the arc tube to the annealing point of the glass (eg, soda glass) constituting the arc tube 100 is performed. The annealing point of soda glass is 520 ° C.

The inventor of the present application observed and measured the residual stress (skewness) of the arc tube 100 before and after performing the annealing treatment. Figures 5 (a) and (b) show the results. FIG. 5 (a) is a traced photograph of the arc tube 100 before the anneal treatment when the strain was measured, and FIG. 5 (b) is a diagram where the distortion of the arc tube 100 after the anneal treatment was measured. It is the figure which traced the photograph. To explain the measuring instruments used here, a distortion tester (manufactured by Toshiba) SVP-10-II (sensitive color method) was used for photography, and a strain tester (manufactured by Luceo) L SM was used for measuring the skewness. —701 (reflective Senarmont method) was used.

In the arc tube 100 before the annealing treatment shown in FIG. 5 (a), the residual stress of the neck convex portion 16 was 34 MPa (strain degree 25 °). On the other hand, in the arc tube 100 after the annealing treatment shown in FIG. 5 (b), the residual stress of the neck convex portion 16 was 1.4 MPa (a skewness of 1 ° or less). The residual stress in the entire arc tube was 1.4 MPa (strain less than 1 °).

In order to examine the difference depending on the presence (or degree) of residual stress, the present inventors conducted a heat cycle (hot / cold water) test on the arc tube 100. This test is

(Approximately 90 ° C) and cold water (approximately 0 ° C) for 30 seconds alternately for 5 cycles. The samples prepared for the experiment are the following four types of arc tubes 100.

(a) Arc tube 100 heat-treated at 520 ° C (slow cooling point of soda glass) for 10 minutes

(b) Arc tube 100 heat-treated at 520 ° C (slow cooling point of soda glass) for 5 minutes

(c) Arc tube 100 without the above annealing process

(d) Not only the annealing process, but also a luminous tube without a slow cooling wrench during glass processing.

Figure 8 shows the results of the heat cycle (hot / cold water) test.

All the arc tubes 100 that were not gradually cooled by the burner were cracked (crack occurrence rate 100%), while all the arc tubes 100 that were annealed at 520 ° C were not cracked (crack incidence rate 0%). The arc tube 100, which was gradually cooled by the burner but not subjected to the annealing treatment, cracked or did not crack (crack occurrence rate: 37.5%). From the above results, it was found that anneal treatment at 520 ° C showed a sufficient effect for preventing cracking even with a holding time of 5 minutes.

In the heat cycle test, the cracks were classified into those that did not crack and those that did not, and the correlation between the cracks and the strain (measured at four locations of the neck convex portion) was examined. At the level where no cracking occurred, the maximum skewness was about 20 ° or less. This is about 27 MPa or less when converted to stress. Figure 10 shows the correlation between the strain gauge angle (skewness) and the stress (residual stress) for soda glass (thickness lmm) for reference.

Here, theoretical considerations on cracking of the arc tube are given. The time t until the specimen breaks is given by the following equation. And

σa: constant stress applied to the test piece

σιο: Critical stress in an inert environment

K ic: Critical value of stress intensity factor for aperture mode I

Y: Dimensionless coefficient determined by the shape of cracks and test pieces, load type, etc. A, n: Overnight fatigue parameters

The fatigue parameter, n, is called the crack growth susceptibility coefficient and is a measure of the difficulty of crack growth, and varies depending on the material and environment. Figure 11 shows the fatigue parameters of soda glass (Source: Glass Engineering Handbook (Asakura Shoten)).

Next, Fig. 12 shows the change in rupture time due to a decrease in stress when the glass thickness is 1 mm.

In the case of fatigue parameters of n = 13-16, the life is 8000-650,000 times at 1/2 stress and 60-40 million times at 1Z4 stress. If the stress is set to about 14Mpa or less, it will be able to withstand a thermal cycle more than 8000 times the heat shock test. This means that it can withstand more than 40,000 heat cycles. If the residual stress can be further reduced to half, it can withstand a heat cycle of 300 million times or more, which means that the probability of crack generation is almost zero. Means something new. As described above, the arc tube of the present embodiment is also theoretically considered.

The technical significance of reducing the residual stress for 100 to 14 MPa or less (preferably 7 MPa or less) becomes clear.

According to the bulb-shaped electrodeless fluorescent lamp 220 of the present embodiment, since the neck portion 13 is formed with the neck concave portion 14 and the neck convex portion 16, the light bulb-shaped non-fluorescent lamp having the same appearance as the incandescent lamp is provided. An electrode fluorescent lamp can be realized. When the residual stress of the net convex portion 16 is 14 MPa or less (preferably 7 MPa or less), cracking of the arc tube 100 of the bulb-type electrodeless fluorescent lamp 220 can be suppressed. I can go.

(Embodiment 2)

Next, a method for manufacturing a bulb-type electrodeless fluorescent lamp (particularly, arc tube 100) according to the embodiment of the present invention will be described with reference to FIGS. 6 (a) to 6 (c). 6 (a) to 6 (c) are process diagrams for explaining the manufacturing method of the present embodiment.

First, an outer tube 10 made of soda glass and a cylindrical inner tube 20 are prepared. The outer tube 10 prepared here has a substantially spherical portion at one end and an opening at the other end, and the size (typically, diameter) of the opening is the inner tube 2. It is made larger than the diameter of the cylinder of 0. In addition, a thin tube 22 for exhaust is attached to the inner tube 20.

Next, as shown in FIG. 6 (a), after setting the inner pipe 20 in the outer pipe 10, the two ends are rotated, and the end of the inner pipe 20 and the outer pipe 10 at the corresponding position are rotated. And a part of the mixture is heated by a burner 70.

Then, as shown in FIG. 6 (b), the heating part (sealing part) melts, and the lower side (cullet part) 10a of the outer tube 10 extends by its own weight.

Thereafter, as shown in FIG. 6 (c), the cullet portion 10a melts down, and the outer tube 10 and the inner tube 20 are joined to form a sealing portion, thereby forming the sealed arc tube. 1 0 0 'is obtained. Further, the neck recess 13 and the neck projection 16 can be formed in the neck 13 by adjusting the wrench 70 between FIGS. 6 (a) to 6 (c). Thereafter, at least the neck portion 13 is gradually cooled by the burner 70.

Thereafter, the arc tube 100 is placed in a furnace and subjected to an annealing process. Annealing treatment The temperature of the furnace for the heating may be around the annealing point (eg, about 520 ° C). Next, the inside of the tube is evacuated and filled with a sealed gas, and the sealing of the thin tube 22 is also completed, so that a completed arc tube 100 is obtained.

By assembling the arc tube 100 with the residual stress reduced in this way, the induction coil 30, the lighting circuit 40, the case 50, and the base 60, a bulb-type electrodeless fluorescent lamp 220 is obtained.

The lighting circuit 40 preferably generates a relatively low frequency of 1 MHz or less (for example, 40 to 500 kHz). In other words, it is preferable that the frequency of the high-frequency voltage applied to the light emitting tube 100 by the lighting circuit 40 be in a relatively low frequency range of 1 MHz or less (for example, 40 to 500 kHz). This means that when operating in the frequency range from 40 kHz to 1 MHz, compared to operating in a relatively high frequency range such as 13.56 MHz or several MHz, Inexpensive general-purpose products used as electronic components for general electronic devices can be used as members that constitute the circuit, and members with small dimensions can be used, resulting in cost reduction and miniaturization. This is because the advantages are great. However, the configuration of the present embodiment is not limited to operation at 1 MHz or less, and can operate in a frequency region such as 13.56 MHz or several MHz.

According to the present invention, at the neck portion of the outer tube located around the sealing portion, the neck concave portion and the neck convex portion are formed in order from the sealing portion. A bulb-type electrodeless fluorescent lamp having an excellent appearance can be provided. When the residual stress of the neck projection 16 is 14 MPa or less, cracking of the arc tube of the bulb-type electrodeless fluorescent lamp can be suppressed. Industrial applicability

INDUSTRIAL APPLICABILITY The bulb-type electrodeless fluorescent lamp of the present invention and its manufacturing method are useful when used as a substitute for incandescent lamps, and have high industrial applicability in that they have good appearance and can suppress cracking of the arc tube.

Claims

Scope of Word

1. A luminous tube filled with luminous gas and having a concave portion;

An induction coil inserted into the recess,

A lighting circuit electrically connected to the induction coil;

A case for housing the lighting circuit,

A base electrically connected to the lighting circuit, and a base attached to the case;

The arc tube comprises a substantially spherical outer tube and an inner tube defining the recess.

In the neck portion of the outer tube, which is located around a sealing portion formed by joining the outer tube and the inner tube, a neck concave portion and a neck convex portion are formed in order from the sealing portion. Is a bulb-shaped electrodeless fluorescent lamp.

2. The spherical spherical electrodeless fluorescent lamp according to claim 1, wherein an appearance of the arc tube is substantially a glass sphere type A shape.

3. The bulb-type electrodeless fluorescent lamp according to claim 1, wherein the neck convex portion and the upper end of the case are close to or in contact with each other.

4. The bulb-shaped electrodeless fluorescent lamp according to any one of claims 1 to 3, wherein a residual stress of the neck projection is 14 MPa or less.

5. The bulb-shaped electrodeless fluorescent lamp according to any one of claims 1 to 4, wherein the residual stress in the neck recess is 14 MPa or less.

6. The bulb-shaped electrodeless fluorescent lamp according to any one of claims 1 to 3, wherein a residual stress of the neck portion including the neck convex portion and the neck concave portion is 7 MPa or less.

7. The bulb-type electrodeless fluorescent lamp according to claim 6, wherein a residual stress of the entire outer bulb in the arc tube is 7 MPa or less.

8. A step (a) of preparing an outer tube having a substantially spherical portion at one end and an opening at the other end, and a cylindrical inner tube;

After setting the inner pipe in the outer pipe, a part of the outer pipe and a part of the inner pipe are separated. Sealing and joining the outer tube and the inner tube (b);

,

In the step (b), a step of forming a neck concave portion and a neck convex portion in a neck portion located around a sealing portion where the outer tube and the inner tube are joined is performed. ), After which at least the neck convex portion is heated to reduce the residual stress of the neck convex portion to 14 MPa or less.

9. The step of reducing the residual stress to 14 MPa or less,

9. The method for producing a bulb-type electrodeless fluorescent lamp according to claim 8, further comprising a step of annealing the glass material constituting the outer tube at a temperature of an annealing point.