JP3267856B2 - Discharge lamp - Google Patents

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 various kinds of illumination, and more particularly to a discharge lamp of a socket insertion type.

[0002]

2. Description of the Related Art Since discharge lamps can emit high-intensity light, they are widely used not only as outdoor lighting and road lighting, but also as vehicle headlights and store lighting. I have.

As one form of the configuration of this discharge lamp, the following socket insertion type is known. That is,
2. Description of the Related Art There is known a discharge lamp configured to support a pair of lead wire supporting members supporting a lead wire of an arc tube serving as a light source in a reflecting mirror by a socket in a state where the pair of lead wire supporting members are inserted into an opening of the reflecting mirror. I have.

In such a socket-insertion type discharge lamp, there is a problem that the socket is easily deteriorated by ultraviolet rays emitted from the light emitting portion of the arc tube. To solve such a problem, Japanese Utility Model Laid-Open No. 7-524
No. 9 discloses a ceramic member and a resin member.
A socket made of members has been proposed. In this socket, the ceramic member is fixed to the opening of the reflector with both lead wire supporting members inserted, and the resin member is made of ceramic with both lead wire supporting members supported. It is designed to be fixed to a member. A ceramic member that is not likely to be deteriorated by ultraviolet rays cuts ultraviolet rays from the light emitting portion to protect the resin member, while a relatively complicated structure is required to support both lead wire supporting members. In this case, the portion which is difficult to mold is made of a resin member, so that an inexpensive socket free from deterioration due to ultraviolet rays can be obtained.

[0005]

However, when the above-mentioned double-structured socket is employed, a new problem peculiar to the following socket-insertion type discharge lamp arises.

That is, in a discharge lamp, lighting is performed by applying a high voltage to an arc tube, so that a high voltage is also applied to a pair of lead wire supporting members for supporting the lead wires. At this time, if the resin member supporting the pair of lead wire supporting members is formed using a normal resin material, a sufficient interval between the two lead wire supporting members is not secured. In this case, a dielectric breakdown may occur inside the resin member and a short circuit may occur between the two lead wire supporting members (or between the two lead wires when these are insulating members surrounding the lead wires). For this reason, the socket cannot be made compact, and the opening for inserting and mounting the socket becomes large, so that the effective area of the reflecting mirror is reduced by that much, and the lamp efficiency of the discharge lamp is reduced. . In particular, in the case of a small discharge lamp, the lamp efficiency is greatly reduced.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a discharge lamp in which a socket can be made compact.

[0008]

According to the present invention, the above object is achieved by devising a resin member among the two members constituting the socket.

That is, a discharge lamp according to the present invention comprises a reflector having an opening, an arc tube having a pair of lead wires, a pair of lead wire supporting members for supporting each of the lead wires, and a lead wire. A wire support member, and a socket for supporting the reflecting mirror in a state where the wire support member is inserted through the opening portion.In the discharge lamp, the socket is inserted into the opening portion while each of the lead wire support members is inserted. A first member made of ceramics fixed and a second member made of high withstand voltage resin fixed to the first member while supporting each of the lead wire supporting members, wherein the second member is injection-molded. Wherein the gate mark generated by the injection molding is located at an intermediate portion between the pair of lead wire support member support portions in the second member.

The "lead wire supporting member" may be an insulating member arranged to support the lead wire when the lead wire extends to the second member of the socket.
The conductive member may be arranged to extend from the end of the lead wire to the second member of the socket instead of the lead wire.

[0011]

As described above, according to the present invention, the second member constituting the socket together with the first member made of ceramics is made of a member made of high withstand voltage resin. Even when the distance between the lead wire support members is set to be relatively small, the second member causes insulation breakdown due to the high voltage applied between the two lead wire support members, and the second member (or both the lead wires). The short circuit can be prevented from occurring during the period.

Therefore, according to the present invention, the socket of the discharge lamp can be made compact. In addition, since the opening for inserting and mounting the socket can be reduced, the effective area of the reflector increases accordingly, and the lamp efficiency of the discharge lamp improves. In particular, in the case of a small discharge lamp, the lamp efficiency is greatly improved.

Moreover, the second member is a molded product obtained by injection molding, and the gate mark generated by this injection molding is
Since the second member is located at an intermediate portion between the pair of lead wire support member support portions, the following operation and effect can be obtained.

That is, in the injection molded product, a weld line is inevitably formed at a portion where the resin material finally joins in the mold at the time of injection molding, but this weld line has a relatively low temperature. Since the resin material is formed by merging, the tissue is not completely fused. When such a structure is generated at an intermediate portion between the pair of lead wire support members, the dielectric breakdown is likely to occur due to the high voltage applied between the two lead wire support members. Therefore, when the mold is manufactured, if the gate position is set at an intermediate portion between the support portions of the two lead wire supporting members, the resin material is filled into the mold from the gate. There is no risk of lines being formed. Therefore, in the case where the gate mark is located at an intermediate portion between the pair of lead wire support member support portions when considering the second member as an injection molded product, a weld line is formed at the intermediate portion. Can be prevented, whereby the effect of preventing dielectric breakdown can be enhanced.

The term “high withstand voltage resin” means a resin material having particularly excellent withstand voltage characteristics. Specific examples thereof include polyphenylene sulfide (hereinafter referred to as “PP”).
S ". ), Polyetherimide (trade name “Ultem”), and a resin material such as polyamideimide can be used. At this time, if a PPS resin is adopted as the “high withstand voltage resin”, the PPS resin is a resin material that is also very excellent in heat resistance, so that the second member of the socket is also exposed to high temperatures. Even in a small discharge lamp, a supporting function for a lead wire supporting member can be performed without causing burning or thermal deformation.

In the above structure, the term "intermediate portion" literally means a portion located in the middle of a pair of lead wire support member support portions. This "intermediate portion" is defined as a pair of lead wire support members. It can also be interpreted in a limited manner as being located in a circular region whose diameter is a line segment connecting the member supporting portions. This is because if the fusion property of the tissue in the circular region can be maintained at a high level, it is sufficiently effective in preventing dielectric breakdown.

The above-mentioned "lead wire supporting member" is an insulating member arranged to support the lead wire when the lead wire extends to the second member of the socket, or from an end of the lead wire to the lead wire. Although it has already been described that any one of the conductive members arranged so as to extend to the second member of the socket may be used instead, one of the leads of the pair of lead wire supporting members may be used as a specific configuration of the former. The wire support member is constituted by an arc tube base extension which is formed by extending the base end of the arc tube extending in the optical axis direction of the reflecting mirror, and the other lead wire support member is formed by the base from the tip of the arc tube. It is possible to use a tubular lead wire support that surrounds a lead wire that is folded back toward the end. By adopting a configuration in which the arc tube is directly supported by the socket in this manner, the positional accuracy of the light emitting portion of the arc tube can be increased, and the lamp performance can be improved.

In the case of adopting this configuration, the lead wire supporting member supporting portion for supporting the extension portion of the base end of the arc tube is provided with the second supporting member.
It is preferable to provide the socket substantially at the center of the member in order to make the socket more compact or in terms of lamp performance.
In such a case, the lead wire supporting member supporting portion supporting the arc tube base end extension and the lead wire supporting member supporting portion supporting the lead wire support are relatively close to each other. Since the member is made of a high withstand voltage resin as described above, the above configuration can be adopted without fear of dielectric breakdown.

The method of fixing the first member to the opening of the reflecting mirror is not particularly limited. However, if the first member is fixed with an inorganic adhesive, it can be fixed with an organic adhesive even under an ultraviolet irradiation environment. It is possible to securely fix without causing peeling or the like that occurs when fixing is performed.

Further, the method of fixing the second member to the first member is not particularly limited. If the second member is fixed by screwing, the fixing operation of both members can be performed reliably and easily. It is possible to do.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing a discharge lamp according to an embodiment of the present invention.

The discharge lamp 10 according to this embodiment has a UVA
A small discharge lamp (small lamp) having an outer diameter of 100 mm or less for irradiating (ultraviolet light in a long-wavelength region), for example, used for the purpose of raising the display effect by, for example, raising an exhibit white in a store or the like. It is a lighting fixture.

The discharge lamp 10 includes a lens 12, a reflecting mirror 14, an arc tube 16, and a socket 18.

The lens 12 and the reflecting mirror 14 are made of glass and are fixed to each other by an organic adhesive. The lens 12 transmits visible light and U among wavelength components of light from the arc tube 16 reflected by the reflecting mirror 14.
UV by removing VB / UVC (ultraviolet light in the medium and short wavelength region)
It has a filter function that transmits a lot of A. The reflecting mirror 14 has a reflecting surface composed of a paraboloid of revolution having the optical axis Ax as a central axis, and an opening 14a is formed at the top thereafter. The filter function of the lens 12 is shown in the graph of FIG. This graph shows discharge lamp 1
7 shows data obtained by comparing the irradiance of 0 when the lens 12 is mounted (broken line) and when the lens 12 is not mounted (solid line). From this graph, it is clear that by mounting the lens 12, it is possible to transmit only a large amount of UVA.

As shown in FIG. 1, the arc tube 1
6 is a glass tube 20, a pair of electrode rods 22, a pair of molybdenum foils 24, and a pair of lead wires 26A and 26B.
It consists of

The glass tube 20 is disposed so as to extend on the optical axis Ax, and an elliptical spherical discharge chamber 28 is formed at an intermediate portion thereof. The pair of electrode rods 22
Are placed in the discharge chamber 28 on the optical axis Ax.
2 are provided so as to protrude therefrom, and a high-intensity light source is configured by causing a discharge between the two electrode rods 22. The opposite ends of the pair of electrode rods 22 are sealed to the glass tube 20 in a state of being superposed on one end of the pair of molybdenum foils 24. 1 above
The pair of lead wires 26 </ b> A and 26 </ b> B are also sealed in the glass tube 20 with one end thereof being overlapped with the other end of the pair of molybdenum foils 24. The above glass tube 2
Reference numeral 0 indicates that the base end side is formed longer than the distal end side with respect to the position of the discharge chamber 28, and is supported by the socket 18 at the extended arc tube base end extension 20a. .

Of the pair of lead wires 26A and 26B, the lead wire 26A at the base end extends to the rear side of the lamp from the arc tube base extension 20a of the glass tube 20, while the tip end extends. The lead wire 26B on the side extends forward from the front end of the glass tube 20 to the lamp, and is connected to the second lead wire 26B2. This second lead wire 26B2
Is formed in an L-shape, and extends parallel to the glass tube 20 so as to be folded from the distal end portion of the glass tube 20 to the base end side. The second lead wire 26B2 is formed by a ceramic lead wire support 30 formed in a cylindrical shape.
It is surrounded over its entire length. In addition, about the said lead wire 26B and the 2nd lead wire 26B2, these may be comprised by one lead wire.

The socket 18 comprises a ceramic disk 32 and a resin plug 34,
And the lead wire support 30 to the opening 1
4a is supported by the reflecting mirror 14 in a state where it is inserted through. The ceramic disk 32 is made of ceramics, and is fixed to the opening 14a with the inorganic adhesive 36 with the arc tube 16 and the lead wire support 30 inserted therethrough. This inorganic adhesive 3
6 include silica (SiO ₂ ) and alumina (Al
₂ O ₃₎ inorganic adhesives based on (trade name "SUMICERAM S-31AK" {Asahi Chemical Industry Co., Ltd.}) are used. On the other hand, the resin plug 34 is a molded product formed by injection molding a PPS resin material,
While supporting the lead wire support 6 and the lead wire support 30, the ceramic disk 32 is fixed to the ceramic disk 32 with screws 38.

FIGS. 2 and 3 show the ceramic disk 32 and the resin plug 34, respectively, as a single item.
It is a direction arrow view.

As shown in FIGS. 1 and 2, a portion near the center of the ceramic disk 32 is formed to be thick, and an insertion hole 3 through which the arc tube 16 is inserted is formed in the center thereof.
2a are formed, and below the lead support 30a.
An insertion hole 32b through which the screw 38 is inserted is formed at three places around the insertion hole 32a. An annular flange 32d for holding the inorganic adhesive 36 is formed on the outermost peripheral portion of the ceramic disk 32. As shown by a broken line in FIG. 2, on the back surface (rear surface) of the ceramic disk 32, a circular counterbore surface 32e for axial alignment with the resin plug 34 and a pin for positioning in the rotational direction with respect to the resin plug 34 are provided. 32f are formed.

As shown in FIGS. 1 and 3, in the center of the resin plug 34, a support hole 34a for supporting the arc tube 16 and an insertion hole for inserting a lead wire 26A projecting rearward from the arc tube 16 are inserted. 34b are formed concentrically, and the lead wire support 3
0 and a through hole 34d for inserting the second lead wire 26B2 protruding rearward from the lead wire support 30 are formed concentrically. Further, at three places around the support hole 34a, A tap hole 34e for fixing the screw 38 is formed. Also,
At a position corresponding to the pin 32f of the ceramic disk 32, an engagement groove 34f that engages with the pin 32f is formed.

As shown in FIG. 1, the lead wire 26A and the second lead wire 26B2 extend through the resin plug 34, and the lead wire 26A is connected to a boss 34g formed on the rear surface of the resin plug 34. The second lead wire 2 is fixed to the fitted metal cap 40 by laser welding.
6B2 is fixed by laser welding to a metal band 42 wound around the peripheral surface of the resin plug 34.

In FIG. 3, the crosses indicated by broken lines indicate the positions of the gate marks formed when the resin plug 34 is injection-molded. The crosses indicate the positions of the through holes 34b of the lead wire 26A and the first holes. The two lead wires 26B2 are set so as to be located on a straight line connecting the insertion hole 34d.

Next, the operation of the present embodiment will be described.

In this discharge lamp 10, the socket 18
When a connector (not shown) is attached to the resin plug 34, the cap 40 and the band 42 are connected to the power supply side circuit. When a voltage is applied between the cap 40 and the band 42, the arc tube 16 Discharge occurs between the pair of electrode rods 22 to emit light, but immediately after the lighting, a high voltage is applied between the cap 40 and the band 42, so that the high voltage causes the lead wire 26A and the second lead wire. It is important to prevent a short circuit from occurring with 26B2.

However, the lead wire 26A and the second lead wire 26B2 are connected to the cap 40 and the band 4
2, the rear end is exposed from the arc tube base end extension 20a and the lead wire support 30, and in this exposed state, the insertion hole 34 of the resin plug 34 is formed.
b and the insertion hole 34d. Therefore, if the resin plug 34 is made of a normal resin material, a short circuit may occur between the lead wire 26A and the second lead wire 26B2 due to a high voltage at the time of lighting. Therefore, in order to prevent a short circuit in this case, it is necessary to set the interval between the lead wire 26A and the second lead wire 26B2 to be considerably larger than the illustrated size.
For this reason, it is difficult to employ a configuration in which the arc tube base end extension 20a is supported at the center of the resin plug 34, so that the socket 18 can be made compact, and the light emitting portion of the arc tube 16 (in the discharge chamber 28). It is difficult to improve the lamp performance by increasing the positional accuracy of the portion between the pair of electrode rods 22).

On the other hand, in the present embodiment, since the resin plug 34 is made of a member made of PPS resin, which is a resin material having particularly excellent withstand voltage characteristics, as shown in FIG. Even when the interval between the lead wire 26B2 and the lead wire 26B2 is set relatively small, the high voltage at the time of lighting causes the resin plug 34 to cause dielectric breakdown, and
It is possible to prevent a short circuit from occurring between 6A and the second lead wire 26B2.

Therefore, according to the present embodiment, the socket 18 of the discharge lamp 10 can be made compact. And, by this, the opening 14 for inserting and inserting the socket is formed.
a can also be reduced, so that the reflecting mirror 1
4, the effective area of the discharge lamp 10 is increased, and the lamp efficiency of the discharge lamp 10 is improved. In particular, in a small discharge lamp as in this embodiment, the lamp efficiency is greatly improved.

Further, since the PPS resin is a resin material which is very excellent also in terms of heat resistance, not only the ceramic disk 32 of the socket 18 but also the resin plug 34 is exposed to a high temperature. In discharge lamps,
By using the resin plug 34 made of the PPS resin, a function of supporting the arc tube base end extension 20a and the lead wire support 30 can be achieved without causing burnout or thermal deformation.

The resin plug 34 is an injection-molded product. As shown by crosses in FIG. 3, gate traces generated by the injection molding indicate the insertion hole 34b for the lead wire 26A and the insertion hole for the second lead wire 26B2. 34d, the weld line is not formed between the insertion hole 34b and the insertion hole 34d of the resin plug 34 during injection molding. Therefore, the effect of preventing dielectric breakdown between the lead wire 26A and the second lead wire 26B2 against a high voltage during lighting can be enhanced.

Further, in the present embodiment, the fixing of the ceramic disk 32 and the opening 14a of the reflecting mirror 14 is performed by an inorganic adhesive.
Even in an ultraviolet irradiation environment, it is possible to reliably fix without peeling or the like that occurs when fixing with an organic adhesive. Further, since the resin plug 34 and the ceramic disk 32 are fixed by screwing, the resin plug 34 and the ceramic disk 32 are fixed.
Can be reliably and easily performed.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a discharge lamp according to an embodiment of the present invention.

FIG. 2 is a diagram showing the ceramic disk of the embodiment as a single item, as viewed in the direction of arrow II in FIG. 1;

FIG. 3 shows the resin plug of the embodiment as a single item.
View in the direction of arrow II

FIG. 4 is a graph for explaining a filter function of the lens according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Discharge lamp 12 Lens 14 Reflector 14a Opening 16 Arc tube 18 Socket 20 Glass tube 20a Arc tube base end extension part (lead wire support member) 22 Electrode bar 24 Molybdenum foil 26A, 26B Lead wire 26B2 2nd lead wire (Lead 28) Discharge chamber 30 Lead wire support (lead wire support member) 32 Ceramic disk (first member) 32a, 32b, 32c Insertion hole 32d Annular flange 32e Counterbore face 32f Pin 34 Resin plug (second member) 34a, 34c Support hole 34b, 34d Insertion hole 34e Tapped hole 34f Engagement groove 34g Boss 36 Inorganic adhesive 38 Screw 40 Cap 42 Band × mark Gate mark Ax Optical axis

Continuation of the front page (56) References JP-A-6-20652 (JP, A) JP-A-64-82911 (JP, A) JP-A-7-224223 (JP, A) JP-A-7-5249 (JP) , U) Shokai 56-60272 (JP, U) Shogun 46-29588 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01R 33/02-33/965 H01J 5/48

Claims (7)

(57) [Claims] A reflector having an opening, an arc tube having a pair of lead wires, a pair of lead wire support members for supporting each of the lead wires, and the lead wire support member being mounted in the opening. And a socket that is supported by the reflector when the lead wire is inserted. The first socket made of ceramics, wherein the socket is fixed to the opening while the respective lead wire support members are inserted. And a second member made of a high withstand voltage resin fixed to the first member while supporting each of the lead wire supporting members, wherein the second member is a molded product by injection molding. A discharge lamp, wherein a gate mark generated by injection molding is located at an intermediate portion between the pair of lead wire support member support portions in the second member. 2. The discharge lamp according to claim 1, wherein the high withstand voltage resin is a polyphenylene sulfide resin. 3. The discharge device according to claim 1, wherein the intermediate portion is located in a circular region having a diameter corresponding to a line connecting the pair of lead wire support members. Electric lights. 4. The arc tube is disposed so as to extend in an optical axis direction of the reflecting mirror, and one of the pair of lead wires extends from a distal end to a proximal end of the arc tube. A pair of lead wire support members, the pair of lead wire support members being formed by extending a base end of the arc tube; and a base end side from a tip end of the arc tube. The discharge lamp according to any one of claims 1 to 3, further comprising: a tubular lead wire support surrounding the lead wire that extends back. 5. A lead wire support member supporting portion for supporting the arc tube base end extension portion of the pair of lead wire support member support portions of the second member is provided substantially at the center of the second member. The discharge lamp according to claim 4, wherein 6. The fixing of the first member to the opening,
The discharge lamp according to any one of claims 1 to 5, wherein the discharge lamp is made of an inorganic adhesive. 7. The discharge lamp according to claim 1, wherein the second member is fixed to the first member by screwing.