JP2011204642A - Electrodeless discharge lamp and lighting fixture using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp capable of preventing damage on a bulb caused by vibration of an exhaust thin tube, and a lighting fixture using the electrodeless discharge lamp.SOLUTION: The electrodeless discharge lamp includes a light-transmitting bulb 1 wherein a rare gas as a discharge gas and mercury are enclosed, an induction coil for generating a high-frequency electromagnetic field, and a phosphor film 4 arranged at an inner wall surface side of the bulb 1 and converting an ultraviolet ray generated with discharge caused by an action of the high-frequency electromagnetic field into visible light. The bulb 1 is formed by joining ends at a base 2 side between a bulb body 1a formed at an electric bulb-shape and opening an end at a base 2 side and a cavity formation section 1b opening the base 2 side and formed at a cylindrical shape with a bottom, and prepares a thin-walled section 9 thinner than the other portion containing a first portion 6 at the other end rather than the first portion 6 where the maximum shearing stress is added to the exhaust thin tube 7, while one end is connected to a bottom 5a of the cavity formation section 1b and the exhaust thin tube 7 sealing the other end is arranged on the cavity formation section 1b.

Description

  The present invention relates to an electrodeless discharge lamp and a lighting fixture using the same.

  Conventionally, as an electrodeless discharge lamp, for example, as shown in FIG. 3A, a light-transmitting material such as a rare gas (for example, argon gas or krypton gas) that is a discharge gas and glass in which mercury is enclosed. A valve 1 made of a material, an induction coil (not shown) that generates a high-frequency electromagnetic field when a high-frequency current is applied, and a philite core (not shown) around which the induction coil is wound. There has been proposed one including a coupler 16 (see, for example, Patent Document 1). A protective film 3 for protecting the valve 1 is attached to the inner wall surface of the valve 1. Further, on the side opposite to the inner wall surface side of the bulb 1 in the protective film 3, a phosphor film 4 that converts ultraviolet rays generated by discharge gas discharge by the action of a high-frequency electromagnetic field into visible light is deposited.

  The bulb 1 is formed by joining the end portions on the base 2 side of a bulb body 1 a formed in a bulb shape and having an end on the base 2 side opened, and a bottomed cylindrical cavity forming portion 1 b opened on the base 2 side. It is comprised by doing.

  The cavity forming portion 1b is provided with an exhaust thin tube 7 having one end connected to the bottom 5a of the cavity forming portion 1b, the internal space communicating with the internal space of the valve body 1a, and the other end sealed. . A metal container 12 in which a mercury amalgam 11 for supplying mercury vapor into the valve 1 is enclosed is accommodated inside the exhaust thin tube 7.

  As shown in FIG. 3 (b), the bottom 5a of the cavity forming portion 1b is formed with a welded portion 5b in which the one end of the exhaust thin tube 7 is welded. The actual welded portion 5b is shown in FIG. As shown, the bottom portion 5a of the cavity forming portion 1b made of glass and the one end portion of the exhaust thin tube 7 are melted and welded, so that it has a curved shape with a curvature.

  Here, not only the electrodeless discharge lamp described above, but a lamp having a bulb formed of glass must be configured to prevent the glass fragments of the bulb from scattering even if the lamp is broken. What is not necessary is defined in the Japan Light Bulb Industry Association Standard JEL218, Japan Industrial Standard JIS C7601, and the like.

  As a lamp having a bulb formed of glass, for example, a fluorescent lamp formed of a light-transmitting resin (polyester resin or the like) and covered with a bulb for preventing scattering of glass fragments has been commercialized. Yes.

  In addition, as another lamp having a bulb formed of glass, a high-intensity discharge lamp in which the outer surface of a bulb formed of hard glass is covered with a film made of a fluororesin has been proposed (for example, Patent Document 2). As another high-intensity discharge lamp, a glass tube made of hard glass with viscosity that prevents scattering of glass fragments is placed so as to cover an arc tube filled with mercury, metal halide, and rare gas. What has been proposed is proposed. (For example, refer to Patent Document 3).

  In addition, a lamp having a bulb formed of glass is housed in a housing made up of a bowl-shaped reflector that reflects light from the lamp and a front panel formed of a light-transmitting material. There is known a lighting fixture that prevents glass fragments from being scattered at the time of breakage.

JP 2007-317571 A Japanese Patent Publication No.7-111946 Japanese Patent Laid-Open No. 11-288696

  By the way, in the electrodeless discharge lamp illustrated in FIGS. 3 and 4, the bottom 5a of the cavity forming portion 1b made of glass and the one end of the exhaust thin tube 7 are melted, and the bottom 5a of the cavity forming portion 1b and the exhaust thin tube 7 are melted. The one end part of the exhaust pipe 7 is welded, and the exhaust thin tube 7 has a cantilever structure with the welded part 5b as a fixed end. Therefore, for example, when an impact is applied from the outside during transportation or use of the above electrodeless discharge lamp or a lighting fixture equipped with this electrodeless discharge lamp, the exhaust thin tube 7 vibrates with the welded portion 5b as a fixed end, The stress generated by vibration may concentrate on the welded part 5b. As a result, there is a concern that cracks may occur in the welded portion 5b. Here, regarding the above-mentioned electrodeless discharge lamp, in the cross section orthogonal to the radial direction of the exhaust thin tube 7, the curved portion of the welded portion 5 b having a curvature in a part of the exhaust thin tube 7 and the straight portion of the exhaust thin tube 7. The stress generated by the vibration of the exhaust thin tube 7 may concentrate on the boundary portion 6 (see FIG. 4), which is a boundary, and there is a concern that cracks may occur in the boundary portion 6.

  In the above electrodeless discharge lamp, the internal pressure of the bulb 1 is lower than the atmospheric pressure, and the inner wall surface of the cavity forming portion 1b is pressed by the atmospheric pressure (the inner wall surface of the cavity forming portion 1b is shown in FIG. ) And the atmospheric pressure in the direction of the arrow shown in FIG. 4 is pressed at about 9.8 [N] per unit area). Therefore, since the bottom 5a of the cavity forming portion 1b is pressed by atmospheric pressure, there is a concern that the bottom 5a of the cavity forming portion 1b may be damaged if cracks occur in the welded portion 5b or the boundary portion 6. As a result, there is a concern that glass fragments on the bottom 5b of the cavity forming portion 1b jump into the bulb 1 and collide with the inner wall surface of the bulb 1 to damage the bulb 1.

  Further, in a high-intensity discharge lamp covered with a coating made of a fluororesin, if the bulb is broken, glass fragments of the bulb can be prevented from scattering, but this does not prevent the bulb from being broken.

  In the high-intensity discharge lamp having the other configuration described above, when the arc tube is ruptured, glass fragments of the arc tube can be prevented from being scattered, and the bulb can be prevented from being damaged. However, in an electrodeless discharge lamp having a complicated bulb shape, it is difficult to dispose a glass tube that prevents glass fragments from scattering at the cavity forming portion.

  The present invention has been made in view of the above-mentioned reasons, and an object thereof is to use an electrodeless discharge lamp capable of preventing a bulb from being damaged due to vibration of an exhaust tube, and the same. It is to provide a luminaire.

  The electrodeless discharge lamp of the present invention includes a bulb formed of a light-transmitting material in which a rare gas and mercury as discharge gases are enclosed, an induction coil that generates a high-frequency electromagnetic field when energized with a high-frequency current, And a phosphor film that converts ultraviolet rays generated by the discharge of the discharge gas by the action of the high-frequency electromagnetic field provided on the inner wall surface side of the bulb into visible light, and the bulb is formed in a bulb shape and has a base side The end portion on the base side of the valve body having an open end, and a cavity forming portion that is formed in a bottomed cylindrical shape with the base side open at a portion other than the valve body and inserted into the valve body The cavity forming portion is configured such that one end of the cavity forming portion is connected to the bottom of the cavity forming portion, the inner space communicates with the inner space of the valve body, and the other end. A sealed exhaust tubule is provided, and the exhaust tubule is closer to the other end than the first portion where the maximum shear stress is applied to the exhaust tubule from other portions including the first portion. Is also provided with a thin thin portion.

  The luminaire of the present invention includes an electrodeless discharge lamp and a housing that holds the electrodeless discharge lamp.

  The electrodeless discharge lamp of the present invention has an effect that it is possible to prevent the bulb from being damaged due to the vibration of the exhaust thin tube.

  In the lighting fixture of the present invention, since the breakage of the bulb of the electrodeless discharge lamp is prevented, it is possible to prevent the casing from being damaged or broken.

The electrodeless discharge lamp of embodiment is shown, (a) is a schematic sectional drawing, (b) is the principal part enlarged view of (a). It is a schematic explanatory drawing which shows the lighting fixture of embodiment. The electrodeless discharge lamp of a prior art example is shown, (a) is a schematic sectional drawing, (b) is the principal part enlarged view of (a). It is a principal part enlarged view which shows the electrodeless discharge lamp of another structure same as the above.

  Hereinafter, the electrodeless discharge lamp of this embodiment will be described with reference to FIG. 1. The structure of the electrodeless discharge lamp is substantially the same as that of the conventional electrodeless discharge lamp shown in FIG. Constituent elements similar to those of the conventional example shown are denoted by the same reference numerals and description thereof is omitted as appropriate.

  The electrodeless discharge lamp of the present embodiment includes a bulb 1 formed of a light-transmitting material (for example, glass) in which a rare gas (for example, argon gas or krypton gas) that is a discharge gas and mercury are enclosed; And an induction coil (not shown) that generates a high-frequency electromagnetic field when a high-frequency current is applied. Here, a protective film 3 for protecting the valve 1 is attached to the inner wall surface of the valve 1. Further, on the side opposite to the inner wall surface side of the bulb 1 in the protective film 3, a phosphor film 4 that converts ultraviolet rays generated by discharge gas discharge by the action of a high-frequency electromagnetic field into visible light is deposited. The protective film 3 is made of a metal oxide such as aluminum oxide (alumina) or silicon dioxide (silica). Further, the laminated film of the protective film 3 and the phosphor film 4 is formed on substantially the entire inner wall surface of the bulb 1, and only a part thereof is shown in FIG.

  Since the inside of the bulb 1 is evacuated in the manufacturing process of the electrodeless discharge lamp, and the rare gas and the mercury are sealed and kept in a state close to vacuum, the internal pressure of the bulb 1 is higher than the atmospheric pressure. It is low.

  The induction coil is wound around a cylindrical phyllite core (not shown) that is sheathed on the exhaust thin tube 7. Further, a coupler 16 including the induction coil and the philite core is accommodated in the cavity forming portion 1b. Further, a cylindrical base 2 made of synthetic resin for fixing the coupler 16 to the cavity forming portion 1b is attached to the base 2 side of the valve body 1a.

  The exhaust thin tube 7 contains a metal container 12 in which a mercury amalgam (for example, Zn-Hg or Bi-In-Hg) 11 for supplying mercury vapor into the valve 1 is enclosed, and the metal container 12 is connected to the exhaust thin tube 7. A recessed portion 8 is provided in the exhaust thin tube 7 so as to prevent it from coming off on one end side (the upper end side in FIG. 1A).

  As shown in FIG. 1 (b), the exhaust thin tube 7 is located at the other end side of the exhaust thin tube 7 (the lower end in FIG. 1 (a)) than the portion where the maximum shear stress is applied to the exhaust thin tube 7 (first portion). On the part side), a thin part 9 is formed which is thinner than other parts including the above part where the maximum shear stress is applied. The thin portion 9 is formed over the entire circumference of the cavity forming portion 1b and has substantially the same thickness over the entire circumference. Here, the strength of the maximum shear stress is the shape of the cavity forming portion 1b (length, outer diameter and thickness along the longitudinal direction of the cavity forming portion 1b), and the shape of the exhaust thin tube 7 (longitudinal direction of the exhaust thin tube 7b). Length, outer diameter and wall thickness), the weight of the exhaust thin tube 7, the weight of the metal container 12 in which the mercury amalgam 11 is sealed, the position of the metal container 12, and the shape of the bottom 5a of the cavity forming part 1b, etc. The portion where the maximum shear stress is applied to the exhaust thin tube 7 is different from the curved portion of the welded portion 5b having a curvature in a part of the exhaust thin tube 7 in the cross section perpendicular to the radial direction of the exhaust thin tube 7. It is the boundary part 6 vicinity which is a boundary with the straight part. Therefore, when an impact is applied from the outside, the exhaust thin tube 7 vibrates with the boundary portion 6 as a fixed end, and the thin portion 9 is liable to be broken before the portion where the maximum thin shear stress is applied to the exhaust thin tube 7. As a result, the bottom 5a of the cavity forming portion 1b is not damaged, only the exhaust thin tube 7 is damaged, and only the air is sucked into the valve 1, so that the valve 1 is not damaged. That is, it is possible to prevent the valve 1 from being damaged by damaging the thin portion 9.

  By the way, the inventors of the present application manufactured an electrodeless discharge lamp of Comparative Example 1 in which the thin tube portion 7 was not provided with the thin portion 9, and applied an external impact to investigate the damaged portion of the thin exhaust tube 7. Here, regarding the electrodeless discharge lamp of Comparative Example 1, the dimensions of the cavity forming portion 1b are as follows: the length along the longitudinal direction of the cavity forming portion 1b is 240 [mm], the outer diameter is 47 [mm], and the thickness is It was set to 1.6 [mm]. In addition, the dimensions of the exhaust tubule 7 were 261 [mm] along the longitudinal direction of the exhaust tubule 7, an outer diameter of 8 [mm], and a wall thickness of 1.6 [mm]. Furthermore, the weight of the metal container 12 in which the mercury amalgam 11 is sealed is 1 [g], the dimension of the bottom 5a of the cavity forming portion 1b is about 1.6 [mm], and the radius of curvature of the welded portion 5b. Was set to 2 to 3 [mm].

  As a result of examining the damaged portion of the exhaust thin tube 7, the damaged portion of the exhaust thin tube 7 is in the range of 5 to 10 [mm] from the bottom 5a of the cavity forming portion 1b in the direction along the longitudinal direction of the exhaust thin tube 7. It was found that damage occurred in the range excluding the welded portion 5b. Therefore, the portion where the maximum shear stress is applied to the exhaust thin tube 7 is in the range of 5 to 10 [mm] from the bottom 5a of the cavity forming portion 1b in the direction along the longitudinal direction of the exhaust thin tube 7, and excludes the welded portion 5b. It is considered a range. Similarly, when the exhaust thin tube 7 is damaged by applying a load to the other end portion of the exhaust thin tube 7 and vibrating, the exhaust thin tube 7 is similarly damaged from the bottom portion 5a of the cavity forming portion 1b in the above-mentioned range. There was found.

  Further, an electrodeless discharge lamp of Example 1 having substantially the same structure as the electrodeless discharge lamp of Comparative Example 1 was produced. Here, in the electrodeless discharge lamp of Example 1, the position of the thin portion 9 is provided in the longitudinal direction of the exhaust thin tube 7 on the other end side from the portion where the maximum thin shear stress is applied to the exhaust thin tube 7. The position of the thin portion 9 of the exhaust thin tube 7 is in the range of 15 [mm] from the bottom 5a of the cavity forming portion 1b and excluding the welded portion 5b. Here, the thin portion 9 of the exhaust thin tube 7 is formed by applying a flame of a burner to a position where the thin portion 9 is to be formed in the exhaust thin tube 7 and slightly pulling the exhaust thin tube 7 from both ends when the glass is softened. is there. The thickness of the thin part 9 was 5 [mm] along the longitudinal direction of the thin part 9 and the minimum thickness was 1.0 to 1.2 [mm].

  Furthermore, an electrodeless discharge lamp of Comparative Example 2 having substantially the same structure as that of the electrodeless discharge lamp of Example 1 and changing the position of the thin portion 9 was produced. Here, in the electrodeless discharge lamp of Comparative Example 2, the position of the thin portion 9 was provided in the longitudinal direction of the exhaust thin tube 7 on the one end side than the portion where the maximum thin shear stress was applied to the exhaust thin tube 7. The position of the thin portion 9 of the exhaust thin tube 7 is in the range of 5 [mm] from the bottom portion 5a of the cavity forming portion 1b and excluding the welded portion 5b.

  Here, 20 electrodeless discharge lamps of each of Comparative Example 1, Example 1 and Comparative Example 2 were prepared, and the exhaust thin tubes 7 were provided on the other end side of the exhaust thin tubes 7 of the respective electrodeless discharge lamps. Table 1 shows the results of applying a load until breakage and damaging the exhaust thin tube 7. The numerical values in Table 1 indicate the number of electrodeless discharge lamps.

  As shown in Table 1, the provision of the thin portion 9 in the exhaust thin tube 7 increased the damage to the exhaust thin tube 7 alone. However, in the electrodeless discharge lamp of Comparative Example 2 in which the thin portion 9 is provided on the one end side of the exhaust pipe 7 where the maximum shear stress is applied, the bulb 1 is compared with the electrodeless discharge lamp of Comparative Example 1. Can be reduced, but the breakage of the valve 1 could not be eliminated. Further, in the electrodeless discharge lamp of Example 1 in which the thin portion 9 is provided on the other end side from the portion where the maximum shear stress is applied to the exhaust thin tube 7, only the exhaust thin tube 7 is damaged, and the bulb 1 is damaged. I was able to lose it. Therefore, it is possible to prevent the valve 1 from being damaged by providing the thin portion 9 of the exhaust thin tube 7 on the other end side with respect to the portion where the maximum thin shear stress is applied to the exhaust thin tube 7.

  Further, when the thin thin portion 9 is provided at a position less than 1/3 of the length along the longitudinal direction of the thin exhaust tube 7 from the bottom portion 5a of the cavity forming portion 1b, the thin exhaust portion 7 Could be damaged. However, when the position of the thin portion 9 of the exhaust thin tube 7 becomes a position of 1/3 or more of the length along the longitudinal direction of the exhaust thin tube 7 from the bottom 5a of the cavity forming portion 1b, the maximum thin shear stress is applied to the exhaust thin tube 7. In some cases, the exhaust tube 7 may be damaged at the above-mentioned site.

  Here, the dimensions of the cavity forming portion 1b, the exhaust thin tube 7, the bottom portion 5a of the cavity forming portion 1b, and the thin portion 9 are the dimensions in the test results of this time, and are not limited thereto. Further, the portion where the maximum shear stress is applied to the exhaust thin tube 7 and the strength of the maximum shear stress vary depending on the dimensions and the processing state of the cavity forming portion 1b, the exhaust thin tube 7, the bottom 5a of the cavity forming portion 1b and the thin portion 9. However, the position of the thin portion 9 of the exhaust thin tube 7 is still provided on the other end side of the portion where the maximum shear stress is applied to the exhaust thin tube 7.

  In the electrodeless discharge lamp of the present embodiment described above, it is possible to prevent the bulb 1 from being damaged due to the vibration of the exhaust thin tube 7.

  Hereinafter, an example of the lighting fixture provided with the electrodeless discharge lamp of this embodiment is demonstrated based on FIG.

  A housing 10 composed of a bowl-shaped reflector 10a that reflects light and a front panel 10b formed of a translucent material, and the above-described electrodeless discharge lamp disposed in the housing 10; The electrodeless discharge lamp includes a lighting device 20 that supplies a high-frequency current (for example, a current having a frequency of 13.56 MHz) to the induction coil, and a tube lamp wire 19 that electrically connects the electrodeless discharge lamp. Yes. The lighting device 20 is connected to a plug 22 connected to an AC power source (not shown) including a commercial power source via an electric wire 21.

  By supplying electric power from the AC power source to the lighting device 20 and causing the high-frequency current to flow from the lighting device 20 to the induction coil, a high-frequency electromagnetic field is generated in the bulb 1 and the discharge gas is discharged by the action of the high-frequency electromagnetic field. The ultraviolet rays generated by the above are converted into visible light by the phosphor film 3 (see FIG. 1), and the visible light is emitted to the outside of the bulb 1.

  Here, in the luminaire shown in FIG. 2, the bulb 1 is prevented from being damaged even if the exhaust tube 7 of the electrodeless discharge lamp is damaged. It is possible to prevent the body 10 from being damaged or the housing 10 from being damaged.

  In the lighting fixture of this embodiment described above, since the breakage of the bulb 1 of the electrodeless discharge lamp is prevented, it is possible to prevent the housing 10 from being damaged or broken.

DESCRIPTION OF SYMBOLS 1 Valve 1a Valve body 1b Cavity formation part 2 Base 4 Phosphor film 5a Bottom part 6 1st part 7 Exhaust thin tube 9 Thin part 10 Case

Claims (2)

  Provided on the inner wall side of the bulb, a bulb made of a translucent material enclosing a rare gas and mercury as a discharge gas, an induction coil that generates a high-frequency electromagnetic field when energized with a high-frequency current And a phosphor film that converts ultraviolet rays generated by the discharge of the discharge gas due to the action of the high-frequency electromagnetic field into visible light, and the bulb is formed in a bulb shape and has an end on the base side opened. And by connecting the end portions on the base side to a cavity forming portion inserted into the valve body and formed in a bottomed cylindrical shape with the base side opened at a portion other than the valve body. The cavity forming portion is provided with an exhaust thin tube having one end connected to the bottom of the cavity forming portion, the internal space communicating with the internal space of the valve body, and the other end sealed. The exhaust tubule is provided with a thin part thinner than other parts including the first part on the other end side of the first part where the maximum shear stress is applied in the exhaust tubule. An electrodeless discharge lamp characterized by comprising: A lighting fixture comprising: the electrodeless discharge lamp according to claim 1; and a housing for holding the electrodeless discharge lamp.

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