JPH09180680A - Discharge lamp and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent discharge lamp of long life, by preventing electric breakdown of the base of the discharge lamp due to a high voltage pulse. SOLUTION: An emitting tube 1 has a pair of electrodes 3, 4 in the inside, further an emitting part 2 of elliptic shape formed with a discharge space, and seal parts 5, 6 in both ends of this emitting part 2. The inside of the emitting part 2 is sealed with an emitting metal as a shape of halide. Molybdenum foils 9, 10 are respectively sealed in the seal parts 5, 6, the electrodes 3, 4 and external lead wires 11, 12 are respectively connected to one end and the other end of the molybdenum foils 9, 10. Unseal parts 7, 8 are successively provided in an opposite emitting tube side of the seal parts 5, 6. A base 15, consisting of insulating material, has a receiving part 16. An external/internal peripheral surface 13, 14 of the unseal part 7 is brought into contact with the base 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp used for automobile headlamps and the like.

[0002]

2. Description of the Related Art Conventionally, as a discharge lamp of this type, FIG.
As shown in FIG. 3, a light emitting portion 2 having a pair of electrodes 3 and 4 therein, sealing portions 5 and 6 continuously provided at both ends of the light emitting portion 2, and a non-sealing portion 7 continuously provided to the sealing portion 5. It is known that the non-sealing portion 7 of the arc tube 1 is held by the base 24 via the metal plate 25, and the arc tube 1 having (Japanese Patent Laid-Open No. 4-2
29545).

Such a conventional discharge lamp has a base 24.
The non-sealing portion 7 of the arc tube 1 is inserted into the housing portion 23 of the above, and the metal plate 25 is provided between the base 24 and the non-sealing portion 7. At least the housing portion 23 region of the base 24 is made of meltable plastic, and the melting point of the plastic is higher than the temperature of the non-sealing portion 7 during lamp lighting and lower than the melting point of the arc tube material. is there. Therefore, when the lamp is assembled, the metal plate 2 is heated by high frequency induction heating.
The plastic is melted by heating 5 and the base 2
4 and the non-sealing portion 7 are fixed, whereby the arc tube 1 is fixedly held by the base 24.

[0004]

However, in such a conventional discharge lamp, since the metal plate 25 is located between the base 24 and the non-sealing portion 7, a high voltage pulse necessary for starting the discharge lamp is generated. When applied, creeping discharge from the external lead wire toward the metal plate 25 along the inner surface of the base 24 (see FIG. 3).
(Indicated by the middle arrow), causing dielectric breakdown.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a discharge lamp having an excellent long life by preventing the dielectric breakdown caused in the base of the discharge lamp by a high voltage pulse. It is intended.

[0006]

DISCLOSURE OF THE INVENTION The discharge lamp of the present invention comprises:
An arc tube having a light emitting part having a pair of electrodes therein, a sealing part continuously connected to both ends of the light emitting part, and a non-sealing part continuously connected to at least one of the sealing parts; A non-sealing portion having an outer peripheral surface and an inner peripheral surface in contact with the base in the housing so that the arc tube is held by the base.

As a result, since the outer peripheral surface and the inner peripheral surface of the non-sealing portion are securely held by the accommodating portion,
It has excellent shock resistance and vibration resistance, and since the cylindrical non-sealing part is held only by the base made of an insulating material, creeping discharge in the base is eliminated and the discharge lamp is It is possible to prevent the dielectric breakdown of the base and provide a long-life discharge lamp.

The method of manufacturing a discharge lamp of the present invention is
An arc tube having a light emitting part having a pair of electrodes therein, a sealing part continuously provided at both ends of the light emitting part, and a cylindrical non-sealing part continuously provided at least one of the sealing parts; When obtaining a discharge lamp provided with a base having a housing made of an insulating material, after heating one of the non-sealing parts, the heated non-sealing part is used as the housing part of the base. By inserting under pressure, the outer peripheral surface and the inner peripheral surface of the non-sealing portion are brought into contact with the base in the accommodation portion to hold the arc tube in the base.

As a result, the discharge lamp of the present invention can be easily manufactured.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises: a light emitting part having a pair of electrodes therein; a sealing part continuously provided at both ends of the light emitting part; An arc tube having a cylindrical non-sealing portion continuously provided on at least one side,
A base having an accommodating portion made of an insulating material, wherein the outer peripheral surface and the inner peripheral surface of the non-sealing portion are in contact with the base in the accommodating portion and the arc tube is held by the base. doing.

This has the effect that the outer peripheral surface and the inner peripheral surface of the non-sealing portion can firmly hold the arc tube by the accommodating portion of the base.

Further, according to a second aspect of the present invention, at least one of the light emitting portion having a pair of electrodes therein, the sealing portions connected to both ends of the light emitting portion, and the sealing portion. In obtaining a discharge lamp including an arc tube having a continuous cylindrical non-sealing portion and a base having a housing made of an insulating material, after heating one of the non-sealing portions, By inserting the heated non-sealing portion into the housing portion of the base under pressure, the outer peripheral surface and the inner peripheral surface of the non-sealing portion are brought into contact with the base metal in the housing portion to form the arc tube. It is configured to be held by the base.

As a result, the number of parts of the discharge lamp and the manufacturing process can be reduced, the cost can be reduced, and the discharge lamp according to the present invention can be easily manufactured.

An embodiment of the present invention will be described below with reference to the drawings. An arc tube 1 of a discharge lamp A according to an embodiment of the present invention shown in FIG. 1 has a pair of electrodes 3 and 4 made of, for example, tungsten inside, and has an ellipsoidal light-emitting portion that forms a discharge space. 2 and sealing portions 5 and 6 at both ends of the light emitting portion 2 and non-sealing portions 7 and 8 that are connected to the sealing portions 5 and 6, respectively. Inside the light emitting portion 2, a light emitting metal such as sodium and scandium is enclosed in the form of a halide together with xenon and mercury. The electrodes 3 and 4 are connected to one ends of molybdenum foils 9 and 10, which are introduction foils, and the other ends of the molybdenum foils 9 and 10 are connected to one ends of external lead wires 11 and 12, respectively. The molybdenum foils 9 and 10 are sealed in the sealing portions 5 and 6, respectively. The other ends of the external lead wires 11 and 12 are led out to the outside of the arc tube 1. The circular tube-shaped outer tube 22 can block the ultraviolet rays emitted from the light emitting section 2 during lighting, and is provided so as to cover the light emitting section 2 of the arc tube 1. Both ends of the outer tube 22 are fixed to the non-sealed portions 7 and 8 of the arc tube 1. In addition, the arc tube 1 and the outer tube 22
Is made of quartz glass.

The outer peripheral surface 13 and the inner peripheral surface 14 of the non-sealing portion 7 of the discharge lamp A are in contact with the housing portion 16 of the base 15 so that the arc tube 1 is fixedly held by the base 15. External lead wire 1
The other end of 2 is connected to one end of the power supply line 17,
The other end of the power supply line 17 and the other end of the external lead wire 11 are connected to the electrical connection portions 18 and 19. The discharge lamp A is supplied with electric power from the outside through the electric connecting portions 18 and 19. In addition, as a material of the base 15,
For example, it is made of a thermoplastic resin which is an insulating material such as polyetherimide. The heat distortion temperature of this thermoplastic resin is 210 ° C. The power supply line 17 is covered with a ceramic sleeve 20, and the base 15 is a lid 21 made of ceramic.
Having.

With such a structure, in the discharge lamp A of this embodiment, the non-sealing portion 7 of the arc tube 1 is directly contacted with the base 15 made of an insulating material without using a conductor such as a metal plate. Since it is fixed in place, the creeping discharge in the base 15 can be prevented, the occurrence of dielectric breakdown can be suppressed, and the life can be extended. Further, since it is possible to block the ultraviolet rays emitted from the light emitting unit 2,
It is possible to prevent the arc tube 1 from rattling due to deterioration of the cap 15 due to ultraviolet rays, and it is possible to firmly hold the arc tube 1 by the cap 15 for a long period of time. The method of fixing the arc tube 1 and the outer tube 22 is as follows. Both ends of the outer tube 22 are heated and softened, and the both ends are fixed to the sealed parts 5 and 6 or the non-sealed parts 7 and 8 of the arc tube 1. doing.

Next, a method of manufacturing the discharge lamp of this embodiment will be described. Non-sealing part 7 of arc tube 1 and base 15
As shown in FIG. 2, of the non-sealing parts 7 and 8 of the arc tube 1, after heating the non-sealing part 7 on the base 15 side to 300 ° C.,
The heated non-sealing portion 7 can be obtained by pressing the non-sealing portion 7 into the housing portion 16 of the die 15 while melting the die 15 made of a thermoplastic resin. The non-sealing portion 7 of the base 15 has an outer diameter of 4 mm, and the hole of the accommodating portion 16 has an outer diameter of 3.8 mm. Further, the material of the die 15 may be entirely formed of a thermoplastic resin, or the housing portion 16 and its vicinity may be formed of a thermoplastic resin.

With such a structure, since a metal plate or the like is not used, the number of parts of the discharge lamp and the manufacturing process can be reduced, the cost can be reduced, and the discharge lamp according to the present invention can be easily performed. It can be manufactured.

[0019]

INDUSTRIAL APPLICABILITY As described above, the discharge lamp of the present invention has excellent impact resistance and vibration resistance, prevents creeping discharge in the base, and insulates the base of the discharge lamp by a high voltage pulse. Breakage can be prevented and the life can be extended.

Further, the manufacturing method of the discharge lamp of the present invention can reduce the number of parts of the discharge lamp and the manufacturing process, can reduce the cost, and can easily manufacture the discharge lamp according to the present invention.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a discharge lamp according to an embodiment of the present invention.

FIG. 2 is a view for explaining a method of manufacturing a discharge lamp.

FIG. 3 is a partially cutaway front view of a conventional discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 luminous tube 2 luminous part 3,4 electrode 5,6 sealing part 7,8 non-sealing part 13 outer peripheral surface 14 inner peripheral surface 15 base 16 accommodating part

Claims (2)

[Claims] 1. A light emitting part having a pair of electrodes inside, a sealing part continuous with both ends of the light emitting part, and a tubular non-sealing part continuous with at least one of the sealing parts. And a base having an accommodating portion made of an insulating material, wherein the outer peripheral surface and the inner peripheral surface of the non-sealing portion are in contact with the base in the accommodating portion so that the arc tube is attached to the base. Discharge lamp characterized by being held. 2. A light emitting part having a pair of electrodes inside, a sealing part continuous with both ends of the light emitting part, and a cylindrical non-sealing part continuous with at least one of the sealing parts. When obtaining a discharge lamp comprising a light emitting tube having: and a base having a housing made of an insulating material, after heating one of the non-sealing parts, the heated non-sealing part is connected to the base. Discharge characterized in that the outer peripheral surface and the inner peripheral surface of the non-sealing portion are brought into contact with the base in the housing to press and hold the arc tube in the base by pressure-inserting into the housing. Lamp manufacturing method.