JP2017157351A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp which, even if a luminous tube is expanded due to temperature rising at end-of-life of the lamp, suppresses the occurrence of cracks and holes in the luminous tube and is capable of preventing an outer tube from being damaged beforehand.SOLUTION: A discharge lamp includes a luminous tube 10, an outer tube 20 inwardly accommodating the luminous tube 10, and a linear member 30 held to the external surface 10a of the luminous tube 10 in an elastically deformable manner.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a discharge lamp.

  In rare cases, a discharge lamp such as a metal halide lamp used for a wide range of illumination or the like may break the arc tube.

  Therefore, the outer tube is provided with an arc tube having a pair of electrodes inside and containing a metal halide inside, and an electrically non-connected metal wire spirals on the outer surface of the arc tube. A wound metal halide lamp has been proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-135072

  However, in the invention described in Patent Document 1, when the arc tube expands due to a temperature rise at the end of the lamp life, the arc tube digs in along the metal wire to form a crack or a hole in the arc tube, and as a result, the arc tube is damaged. Since noble gases, metal halides, etc. in the arc tube leak to the outside of the arc tube before reaching the lamp, it is possible to make the lamp unlit and to prevent scattering of the arc tube material that has conventionally occurred However, when a crack or a hole is generated in the arc tube, there is a concern that a fragment of the arc tube is generated. Moreover, there exists a concern that an outer tube | pipe may be damaged by the said fragment.

  The present invention has been made to solve the above problems, and suppresses the occurrence of cracks and holes in the arc tube even when the arc tube expands due to a temperature rise at the end of the lamp life, and breaks the outer tube. It is an object of the present invention to provide a discharge lamp capable of preventing the above-mentioned problem.

  The discharge lamp according to the present invention includes an arc tube, an outer tube that accommodates the arc tube inside, and a linear member that is elastically held on an outer surface of the arc tube.

  It is preferable that the linear member be elastic in the surface direction of the outer surface of the arc tube.

  The linear member is preferably a knitted member.

  There is provided a discharge lamp capable of suppressing the occurrence of cracks and holes in the arc tube even when the arc tube expands due to a temperature rise at the end of the lamp life and can prevent the outer tube from being damaged.

It is a conceptual diagram which shows the structure of the discharge lamp 1 which concerns on embodiment of this invention. It is a conceptual diagram which shows the cross section of the arc tube 10 of FIG. It is a conceptual diagram which shows one form of a structure of the linear member 30 of FIG. 2 is a conceptual diagram showing an embodiment of a preferred configuration in which the linear member 30 can be made elastic in the surface direction of the outer surface 10a of the arc tube 10. FIG. It is a conceptual diagram which shows the structure of the discharge lamp 1A which concerns on other embodiment of this invention.

  Hereinafter, a discharge lamp according to an embodiment of the present invention will be described with reference to the drawings. Note that each of the embodiments described below shows a preferred specific example of the present invention. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, manufacturing steps, order of manufacturing steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements. Also, the following figures are schematic diagrams and are not necessarily shown strictly.

  When the arc tube expands due to an increase in temperature at the end of the lamp life, the present inventor, as a cause of the arc tube biting along the metal wire, stress concentration of the metal wire on the tube wall of the arc tube when the arc tube expands Therefore, the present invention has been completed.

  That is, even when the arc tube expands at the end of the lamp life, the linear member such as the metal wire is elastic while being held on the outer surface of the arc tube. Since the member also expands, it has been found that the stress concentration of the linear member on the tube wall of the arc tube can be suppressed.

  FIG. 1 is a conceptual diagram showing a configuration of a discharge lamp 1 according to the present embodiment. FIG. 2 is a conceptual diagram showing a cross section of the arc tube 10 of FIG. FIG. 3 is a conceptual diagram showing an embodiment of the configuration of the linear member 30 of FIG.

  As shown in FIG. 1, the discharge lamp 1 according to the present embodiment is elastically held on an arc tube 10, an outer tube 20 that accommodates the arc tube 10 inward, and an outer surface 10 a of the arc tube 10. The linear member 30 is provided.

  Here, “held elastically on the outer surface 10a of the arc tube 10” means that the linear member 30 is held elastically in contact with the outer surface 10a of the arc tube 10 itself; This includes a case in which a part of the outer surface 10a of the arc tube 10 is elastically contacted and held by another part (for example, the support member 40). In the present embodiment, the former will be described for the sake of convenience.

  The term “contact” refers to the case where the linear member 30 is in contact with the outer surface 10a of the arc tube 10 before the discharge lamp 1 is turned on, and the arc tube while the arc tube 10 is expanding due to the temperature rise. The case where it contacts the outer surface 10a of 10 is included. In the present embodiment, the former will be described for the sake of convenience.

  Further, the term “elasticity” as used herein refers to deformation that occurs in an object when a force (specifically, a pushing force, a pulling force, a spreading force, etc.) is applied to the object (in the present invention, the linear member 30). However, it means the property of returning to the original state when the force is removed.

  As described above, in the discharge lamp 1 according to this embodiment, the linear member 30 is elastically held on the outer surface 10a of the arc tube 10, so that the arc tube 10 expands due to a temperature rise at the end of the lamp life. However, since the linear member 30 expand | swells in connection with it, the stress concentration to the tube wall of the said arc tube 10 of the linear member 30 can be suppressed. Therefore, the occurrence of cracks and holes in the arc tube can be suppressed, and the outer tube can be prevented from being damaged. Further, since the linear member 30 is held on the outer surface 10a of the arc tube 10, it has a reinforcing effect on the arc tube 10 itself.

  The arc tube 10 has a configuration as shown in FIG. 2, for example.

  As shown in FIG. 2, the arc tube 10 is provided between the main tube portion 10A, the narrow tube portion 10B provided at both ends of the main tube portion 10A, and between the main tube portion 10A and the thin tube portion 10B. A reduced diameter portion 10C having an inner diameter reduced from the portion 10A toward the thin tube portion 10B is provided. That is, the main tube portion 10A, the narrow tube portions 10B and 10B, and the reduced diameter portions 10C and 10C constitute the tube wall of the arc tube 10.

  The tube wall of the arc tube 10 is made of translucent alumina ceramics, for example.

  A pair of electrodes 12 and 14 are provided inside the narrow tube portions 10B and 10B so as to face each other. The pair of electrodes 12 and 14 includes electrode cores 12a and 14a, tip coils 12b and 14b, in-capillary coils 12c and 14c, electrode supports 12d and 14d, and sealing materials 12e and 14e.

  The electrode cores 12a and 14a are rod-shaped bodies made of a heat-resistant metal such as tungsten. The tip coils 12b and 14b are coil bodies wound around the tip portions of the electrode cores 12a and 14a, and are made of a heat-resistant metal such as tungsten. The narrow tube coils 12c and 14c are coil bodies wound around the base ends of the electrode cores 12a and 14a, and are made of a heat-resistant metal such as tungsten. The electrode supports 12d and 14d are rod-like bodies connected to the base ends of the electrode cores 12a and 14a, and are made of, for example, cermet having corrosion resistance against metal halides. The electrode supports 12d and 14d are connected to a support member 40, which will be described later, thereby accommodating and supporting the arc tube 10 inside the outer tube 20. The sealing materials 12e and 14e are made of an oxide brazing material having corrosion resistance against metal halides, and fix the electrode supports 12d and 14d to the thin tube portions 10B and 10B. Seal the wall tightly.

  The tube wall of the arc tube 10 is filled with a rare gas as a starting auxiliary gas, a metal halide for generating light by discharge, and a metal as a buffer gas. Argon gas, xenon gas, or the like is used as the rare gas. As the metal halide, halides such as sodium, thallium and calcium, and rare earth metal halides are used. As the rare earth metal, thulium, fornium, dysprosium and the like are preferably used. Mercury is used as the metal as the buffer gas.

  As the outer tube 20, for example, a BT type outer sphere made of transparent hard glass and having one end closed is used. The inside of the outer tube 20 is kept in a vacuum state or is filled with an inert gas (for example, argon gas). The outer tube 20 is not limited to a BT type outer sphere, and may be a straight tube type with one end closed. The material of the outer tube 20 is not limited to transparent hard glass, and any material may be used as long as it can maintain the function as a discharge lamp.

  A base 50 is attached to the other end of the outer tube 20 that is not closed. The base 50 is a power receiving unit that closes the other end of the outer tube 20 and receives power for causing the arc tube 10 to emit light from the outside of the discharge lamp. The base 50 has a shape that can be detachably attached to the socket of the lighting device, and can supply power to the arc tube 10 in the discharge lamp 1 by being attached to the socket.

  A stem 60 attached to the base 50 is provided inside the outer tube 20. In the stem 60, for example, a plurality of lead wires (not shown) are arranged. This lead wire is a metal wire for supplying electric power for lighting the discharge lamp 1 from the base 50 to the arc tube 10.

  The support member 40 has a structure framed by a metal rod frame extending from a lead wire in the stem 60, one end of which is connected to the stem 60 and the other end is connected to the inner wall of the outer tube 20. They are in contact with each other and are connected to the electrode supports 12 d and 14 d of the arc tube 10. Thus, electric power for lighting the discharge lamp 1 is supplied to the pair of electrodes 12 and 14 in the arc tube 10 and the arc tube 10 is fixed. Thus, the arc tube 10 is supported and accommodated inside the outer tube 20.

  As shown in FIG. 1, the linear member 30 is configured in a mesh shape.

  Note that the net shape here means that, for example, as shown in FIG. 3, the heat resistant wires 30 </ b> A constituting the linear member 30 are alternately intersected.

  By using such a linear member 30, it can be made elastic at least in the direction away from the outer surface 10a of the arc tube 10 (the direction in which the arc tube expands due to the temperature rise at the end of the lamp life). Moreover, even if a broken piece of the arc tube 10 is generated, the rate of stopping the broken piece with the linear member 30 is higher than that of the metal wire wound in a spiral shape as described in Patent Document 1 described above. be able to.

  The linear member 30 is preferably elastic in the surface direction of the outer surface 10 a of the arc tube 10.

  When the discharge lamp is repeatedly turned on and off at the end of the lamp life, the arc tube 10 repeats expansion and contraction. Therefore, by making the linear member 30 elastic in the surface direction of the outer surface 10 a of the arc tube 10, the linear member 30 is generated in one direction due to repeated expansion and contraction of the arc tube 10. Misalignment can be prevented. Therefore, stress concentration on the tube wall of the arc tube 10 of the linear member 30 due to the deviation can be suppressed.

  FIG. 4 is a conceptual diagram showing an example of a preferred configuration in which the linear member 30 can be elastic in the surface direction of the outer surface 10 a of the arc tube 10.

  As shown in FIG. 4, one form of a preferable configuration in which the linear member 30 can be elastic in the surface direction of the outer surface 10a of the arc tube 10 is that the heat resistant wires 30A constituting the linear member 30 are staggered. It is a knitted knitted member that intersects and is knitted into a knitted shape.

  Specifically, the “knitted knitted member” referred to here is a member obtained by knitting a heat-resistant wire 30A into a mesh shape having a plurality of loop portions R1, as shown in FIG. Such a knitted member can be manufactured by hand knitting using a knitting machine, or using a crochet or bamboo needle.

  FIG. 5 is a conceptual diagram showing a configuration of a discharge lamp 1A according to another embodiment of the present invention.

  The discharge lamp 1A shown in FIG. 5 differs from the discharge lamp 1 shown in FIG. 1 in the position where the linear member 30 is disposed. Others are the same as in FIG.

  The discharge lamp 1A according to the present embodiment has a configuration in which the linear member 30 is elastically held on the outer surfaces of both the main tube portion 10A and the reduced diameter portions 10C and 10C of the arc tube 10.

  Expansion of the arc tube 10 in the discharge lamp is likely to occur in the main tube portion 10A in which a large amount of discharge gas is enclosed, but the expansion also occurs in the reduced diameter portions 10C and 10C that are close to the electrodes 12 and 14. It's easy to do. Therefore, it is preferable to hold the linear member 30 elastically on the outer surfaces of both the main pipe portion 10A and the reduced diameter portions 10C and 10C.

  Further, the linear member 30 of the discharge lamp 1A includes a linear member elastically held on the outer surface of the main tube portion 10A of the arc tube 10 and the outer surfaces of the reduced diameter portions 10C and 10C of the arc tube 10. It is preferable that the linear member held elastically has a resilience interlocked with the linear member.

  Thus, compared with the discharge lamp 1 of FIG. 1, since the linear member 30 is disposed also in the reduced diameter portions 10C and 10C, the rate of preventing the outer tube 20 from being damaged can be further increased. In addition, since the linear member 30 has the interlocked elasticity described above, either the main tube portion 10A or the reduced diameter portions 10C, 10C of the arc tube 10 (for example, the main tube portion 10A) is provided. Even when greatly expanded, the linear member 30 arranged on the other side (for example, the reduced diameter portions 10C and 10C) that is not greatly expanded is elastic and the elasticity of the linear member 30 arranged on the other side is greatly increased. Can be supplemented.

  Therefore, even when the arc tube expands due to an increase in temperature at the end of the lamp life, it is possible to further suppress the occurrence of cracks or holes in the arc tube.

  The linear member 30 has elasticity interlocked between the main tube portion 10A and the reduced diameter portions 10C and 10C while being elastically held on the outer surface 10a of the arc tube 10, and The elastic force of the linear member 30 held on the outer surfaces of the reduced diameter portions 10C and 10C is preferably larger than the elastic force of the linear member 30 held on the outer surface 10a of the main pipe portion 10A.

  The expansion of the arc tube 10 is likely to occur in the main tube portion 10A in which a large amount of discharge gas is sealed on the inner surface. Therefore, the linear member 30 disposed in the main tube portion 10A has high elasticity (that is, between the heat resistant wires 30A). However, since the main tube portion 10A is an emission portion that emits light emitted inside, the above configuration causes a decrease in light emission efficiency. Therefore, there is a limit in increasing the elastic force of the main pipe portion 10A.

  Therefore, the linear member that holds the elastic force of the linear member 30 held on the outer surface 10a of the reduced diameter portions 10C and 10C with a small emission amount of light emitted inside to the outer surface 10a of the main pipe portion 10A. Even if the main pipe part 10A expands greatly, the elastic force held in the reduced diameter parts 10C and 10C is suppressed even if the main pipe part 10A is greatly expanded while suppressing the decrease in the luminous efficiency of the main pipe part 10A. Since the high linear member 30 is greatly elastic and compensates for the elasticity of the linear member 30 disposed in the main pipe part 10A, it is possible to further suppress the heat resistant wire 30A from biting into the pipe wall of the main pipe part 10A. .

  Here, the reduction in luminous efficiency means that when the linear member 30 is held on the outer surface 10a of the arc tube 10, the total light transmittance (%) as a discharge lamp is less than 90%. .

  The wire diameter of the heat resistant wire 30A is, for example, 1.0 mm or less, and the width between the heat resistant wires 30A is, for example, 1.0 mm or more and 15.0 mm or less.

  The material of the heat resistant wire 30A referred to in the present invention is not particularly limited as long as it has heat resistance. For example, a metal wire such as molybdenum or tungsten can be used as the heat resistant wire.

  The heat resistant wire 30A is preferably a molybdenum metal wire from the viewpoint of ease of manufacture.

  For example, the linear member 30 is made of a heat-resistant wire 30A using a knitting machine or the like, or hand-knitted using a crochet or bamboo needle, to produce a cylindrical body or a knit shape, and then expand the tubular body. Then, the outer surface 10a of the arc tube 10 is held in contact with it. However, the diameter of the metal wire of the heat resistant wire 30A and the width between the heat resistant wires 30A are adjusted so as to have elasticity in a state where the cylindrical body is expanded and in contact with the outer surface 10a of the arc tube 10 to be held. Is preferred.

  Note that the linear member 30 shown in FIG. 5 is elastic even in the main tube portion 10A and the reduced diameter portions 10C and 10C in a state where, for example, the cylindrical body is expanded and held in contact with the outer surface 10a of the arc tube 10. A knitted tubular body in which the diameter of the metal wire of the heat-resistant wire 30A and the width between the heat-resistant wires 30A is adjusted, and the tubular body is widened to contact the outer surface 10a of the arc tube 10. Hold.

  The discharge lamp preferably has a rated lamp power of 500 W or more and 1500 W or less.

  The discharge lamp having such a rated lamp power has a larger arc tube 10, and accordingly, the amount of start-up auxiliary gas, metal halide, buffer gas, etc. sealed in the arc tube 10 increases. The internal pressure of the arc tube 10 during light emission increases. Therefore, since the probability that the arc tube 10 is damaged is higher than that of a lamp of less than 500 W, a higher effect can be obtained by applying the present invention to such a discharge lamp.

  The rated lamp power represents the lamp power (W) at the time of lighting determined for each lamp model in a catalog or the like.

Example 1
A discharge lamp having a rated lamp power of 680 W was manufactured with the basic structure shown in FIGS.

(1) Arc tube 10
The total length in the axial direction is 80 mm, the maximum inner diameter of the main pipe part 10A is 20 mm, the inner diameters of the thin pipe parts 10B and 10B are 1.5 mm, and the tube wall widths of the main pipe part 10A and the thin pipe parts 10B and 10B are 2 mm. The material is translucent alumina ceramics.

(2) A pair of electrodes 12, 14
The electrode cores 12a and 14a have a diameter of 1 mm, and the thin tube coils 12c and 14c are wound with a metal wire of tungsten (W) having a diameter of 0.3 mm for about 3 turns. The electrode supports 12d and 14d are about 1 mm in diameter and the material is cermet.

(3) Auxiliary auxiliary gas Argon gas.

(4) Sealing materials 12e, 14e
Oxide brazing material.

(5) Linear member 30
A cylindrical body having a network structure as shown in FIG. 3 made of a molybdenum (Mo) metal wire having a wire diameter of 0.3 mm (average width between Mo metal wires: 4 mm).

(6) Outer tube 20
BT type made of hard glass. The outer diameter of the largest part is about 150mm and the total length is about 300mm.

(Example 2)
A cylindrical body (between Mo metal wires) having a basic structure shown in FIGS. 1, 2 and 4 and a Mo metal wire having a wire diameter of 0.3 mm as a linear member 30 having a knitted structure as shown in FIG. The discharge lamp 1 having a rated lamp power of 680 W was manufactured in the same manner as in Example 1 except that the average width of 4 mm was used.

(Example 3)
2, 3, and 5, and a cylindrical body (between Mo metal wires) in which a Mo metal wire having a wire diameter of 0.3 mm as a linear member 30 has a mesh structure as shown in FIG. 3. A discharge lamp 1 having a rated lamp power of 680 W, which was the same as that of Example 1, except that the average width was 4 mm, was produced.

Example 4
2, 4, and 5 have a basic structure, and a linear body 30 is formed of a Mo metal wire having a wire diameter of 0.3 mm in a knitted structure as shown in FIG. 4 (between Mo metal wires). The discharge lamp 1 having a rated lamp power of 680 W was manufactured in the same manner as in Example 1 except that the average width of 4 mm was used.

(Comparative Example 1)
A discharge lamp 1 having a rated lamp power of 680 W, which is the same as that of Example 1, except that the basic structure shown in FIGS.

  When the total light transmittance (%) of the discharge lamp 1 of Examples 1 to 4 and Comparative Example 1 was evaluated, it was 98% in Comparative Example 1 and 95% in Example 1. Example 2 was 93%, Example 3 was 93%, and Example 4 was 91%, both of which were satisfactory levels.

1 discharge lamp 10 arc tube 20 outer tube 30 linear member

Claims (3)

Arc tube,
An outer tube that houses the arc tube inside;
A linear member elastically held on the outer surface of the arc tube;
A discharge lamp comprising:   The discharge lamp according to claim 1, wherein the linear member is elastic in a surface direction of an outer surface of the arc tube.   The discharge lamp according to claim 2, wherein the linear member is a knitted member.

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