JP2011243387A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp having a simple structure and capable of suppressing deterioration of a flange portion.
[Solution]
The discharge lamp of the present invention includes a burner BN provided with a light emitting unit 11 and a socket 7 for holding the burner BN so that the light emitting unit 11 is positioned on the front end side. The socket 7 has a flange portion 71 on the front end side. The flange 71 is provided with a metal cover 8 so as to cover the front end surface. In addition, it is desirable that the metal cover 8 is also welded to the metal cover 8 by welding the protruding piece portion 61 formed on the metal band 6.
[Selection] Figure 1

Description

  The present invention relates to a discharge lamp used in an automotive headlamp device or the like.

  As is known from Patent Document 1 and Patent Document 2, a discharge lamp used for an automotive headlamp is composed of a double-tube burner and a resin socket. The burner is provided with a light emitting portion that is a portion that emits light during lighting, and is held by the socket so that the light emitting portion is located on the front end side of the socket.

JP 2003-297226 A JP 2007-323986 A International Publication No. 2009/130654 International Publication No. 2008/110969 International Publication No. 2009/130640

  Here, recently, in order to make the lamp compact, there is a need to make the distance between the light emitting portion and the socket closer than before. However, with such a design, more heat and ultraviolet rays are emitted from the light emitting part during lighting and reach the socket than before, so that the flange part provided on the front end side of the socket deteriorates. Has occurred. When the flange portion deteriorates, gas is generated, and the gas develops a problem such as fogging of the glass portion of the burner and the lens portion of the headlamp device.

  In addition, as described in Patent Literature 3 to Patent Literature 5, the above-described problem may be solved if all the portions corresponding to the flange portion of the conventional socket are made of metal parts. However, even if the problem of the deterioration of the flange portion can be solved by this means, the structure of the flange becomes complicated, and new problems such as an increase in the number of parts and difficulty in assembling occur.

  An object of the present invention is to provide a discharge lamp having a simple structure and capable of suppressing deterioration of a flange portion.

  In order to achieve the above object, a discharge lamp of the present invention is a discharge lamp comprising a burner having a light emitting portion and a socket for holding the burner so that the light emitting portion is positioned on the front end side. The socket includes a flange portion on a front end side, and the flange portion is provided with a metal cover so as to cover a surface on the front end side.

  According to the present invention, it is possible to suppress deterioration of the flange portion with a simple structure.

The figure for demonstrating the discharge lamp of the 1st Embodiment of this invention. The figure for demonstrating the cross section of the discharge lamp of FIG. The figure for demonstrating the state which looked at the discharge lamp of FIG. 1 from the front end side. The figure for demonstrating the expansion | deployment state of the metal cover of 1st Embodiment. The figure for demonstrating the discharge lamp of the 2nd Embodiment of this invention. The figure for demonstrating the discharge lamp of the 3rd Embodiment of this invention. The figure for demonstrating the expansion | deployment state of the metal cover of 3rd Embodiment. The figure for demonstrating the discharge lamp of the 4th Embodiment of this invention. The figure for demonstrating the cross section of the discharge lamp of FIG. The figure for demonstrating the other example of 4th Embodiment. The figure for demonstrating the other example of a socket. The figure for demonstrating the other example of a metal cover. The figure for demonstrating the other example of fixation of a socket and a metal cover.

(First embodiment)
The discharge lamp of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a discharge lamp according to a first embodiment of the present invention, FIG. 2 is a diagram for explaining a cross section of the discharge lamp of FIG. 1, and FIG. 3 is a discharge lamp of FIG. It is a figure for demonstrating the state which looked at from the front end side. In the present invention, for convenience, the side where the burner is located in the discharge lamp will be referred to as the front end side, and the side where the socket is located will be referred to as the rear end side.

  The discharge lamp shown in FIG. 1 is an HID lamp used in an automobile headlamp device, and includes a double-tube structure burner BN including a portion that emits light during lighting as a main part. An inner pipe 1 is arranged inside the burner BN.

  The inner tube 1 has an elongated shape, and a light emitting portion 11 that is a portion that emits light during lighting is formed near the center thereof. The light emitting portion 11 has a substantially elliptical shape, and a plate-like seal portion 12 is formed at both ends thereof, and a cylindrical portion 14 is continuously formed at both ends thereof via a boundary portion 13. Since the inner tube 1 includes a portion that emits light as described above, it is preferable that the inner tube 1 be made of a material having heat resistance and translucency such as quartz glass.

Inside the light emitting portion 11, a discharge space 111 having a substantially cylindrical shape at the center and a tapered shape at both ends is formed. The volume of the discharge space 111, in the case of vehicle headlights ^are, 10mm ^{3 ~30mm 3,} further it is preferred that a 15 mm ³ 25 mm ^3. A discharge medium is enclosed in the discharge space 111. The discharge medium has a mercury-free configuration consisting only of the metal halide 2 and a rare gas.

  The metal halide 2 is composed of a halide such as sodium, scandium, zinc, or indium. Iodine is optimal as the halogen bonded to these metal halides, but bromine, chlorine, and the like may be combined. The combination of metal halides is not limited to this, and tin or cesium halides may be added.

  The rare gas is composed of xenon. The sealing pressure of the rare gas can be adjusted depending on the purpose. For example, in order to improve characteristics such as the total luminous flux, it is desirable that the sealing pressure is 10 atm or higher, particularly 13 atm or higher at normal temperature (25 ° C.). However, the upper limit is about 20 atm at present in production. In addition to xenon, neon, argon, krypton, or the like can be used as the rare gas, or a combination thereof can be used.

  The electrode mount 3 is sealed to the seal portion 12. The electrode mount 3 includes a metal foil 31, an electrode 32, a coil 33 and a lead wire 34.

  The metal foil 31 is a thin metal plate made of, for example, molybdenum, and is arranged so that its plate-like surface is parallel to the plate-like surface of the seal portion 12.

  The electrode 32 is, for example, an electrode made of so-called tritated tungsten obtained by doping tungsten with thorium oxide. One end of the metal foil 31 is overlapped and connected to the light emitting unit 11 side end, and the other end is disposed in the discharge space 111 so as to face each other with a predetermined distance between the electrodes. Yes. The distance between the electrodes is desirably 3.5 mm to 4.5 mm in terms of appearance in the case of an automotive headlamp. The electrode shape is not limited to a straight rod shape, but may be a non-straight rod shape having a large tip diameter or a shape in which the pair of electrodes have different sizes, such as a direct current lighting type. The electrode material may be pure tungsten, doped tungsten, rhenium tungsten, or the like.

  The coil 33 is a metal wire made of, for example, doped tungsten, and is spirally wound around the axis of the shaft portion of the electrode 32 sealed to the seal portion 12. As the coil design, it is preferable that the coil wire diameter is 30 μm to 100 μm and the coil pitch is 600% or less.

  The lead wire 34 is a metal wire made of molybdenum, for example. One end thereof is overlapped and connected to the metal foil 31 on the opposite side with respect to the light emitting unit 11, and the other end extends to the outside of the inner tube 1 along the tube axis. Among them, one end of an L-shaped support wire 35 made of nickel, for example, is connected to the lead wire 34 extending to the front end side of the lamp by laser welding. For example, a sleeve 4 made of ceramic is attached to the support wire 35 at a portion parallel to the tube axis.

  A cylindrical outer tube 5 is provided concentrically with the inner tube 1 on the outer side of the inner tube 1 configured as described above. These inner and outer pipes are connected by welding the outer pipe 5 near the cylindrical portion 14 of the inner pipe 1. Therefore, a space 51 that is kept airtight is formed between the inner tube 1 and the outer tube 5, and a kind of gas selected from neon, argon, xenon, and nitrogen or a mixed gas is formed in the space 51. It is sealed at a pressure of 0.3 atm or less. As the outer tube 5, it is desirable to use a material having a thermal expansion coefficient close to that of the inner tube 1 and having an ultraviolet blocking property, such as quartz glass to which an oxide such as titanium, cerium, or aluminum is added.

  A metal band 6 made of stainless steel, for example, is provided on the rear end side of the burner BN constituted by these so as to hold the outer peripheral surface thereof. The metal band 6 includes four projecting piece portions 61 extending in a direction substantially perpendicular to the tube axis of the discharge lamp.

  Further, a socket 7 formed of a resin such as PPS or PEI is disposed on the rear end side of the burner BN. On the front end side, a disk-shaped flange portion 71 (diameter = about 31 mm, thickness = about 1.5 mm) formed larger than the main body portion (diameter = 24.7 mm) of the socket 7 is formed. The flange portion 71 is provided with a metal cover 8 so as to cover a front end side surface (hereinafter, front end surface 711).

  On the other hand, at the rear end side of the socket 7, a bottom terminal 91 is formed at the bottom, and a side terminal 92 is formed at the side. A lead wire 34 is formed on the bottom terminal 91, and a support wire 35 is formed on the side terminal 92. It is connected. The bottom terminal 91 and the side terminal 92 are connected to a lighting circuit (not shown) so that the bottom terminal 91 is set to the high voltage side and the side terminal 92 is set to the low voltage side. Is set to about 55 W, which is more than twice the stable power.

  Here, the metal cover 8 will be described in more detail.

  As shown in FIG. 4, the metal cover 8 is formed by cutting out a metal plate made of, for example, aluminum and having a thickness of about 0.5 mm. The metal cover 8 protrudes from the potch portion 81, the inner fixing portion 82, the outer fixing portion 83, and the like. The shape is provided with a piece 84.

  The potch portions 81 are projections provided on the surface located on the front end side of the metal cover 8, and three are formed at equal intervals. This potch portion 81 is a portion serving as a base point when measuring dimensions. For example, LCL (Light Center Length), which is a standard for a discharge lamp, is defined by a distance D1 from the tip of the potch portion 81 to the center between the electrodes. The inner fixing portion 82 is a plurality of fixing pieces made of metal formed on the inner frame of the metal cover 8 and the outer fixing portion 83 is formed on the outer frame of the metal cover 8. When the metal cover 8 is attached to the socket 7, these are bent along the wall surface so as to sandwich the flange portion 71, so that the metal cover 8 is firmly fixed to the socket 7. It can prevent coming off. The protrusions 84 are four metal pieces formed on the inner frame of the metal cover 8, and are formed so as to be substantially perpendicular to the tube axis, like the protrusions 61 of the metal band 6. Has been. Therefore, it is possible to make surface contact with the projecting piece portion 61, and the metal band 6 and the metal cover 8 can be fixed by welding the overlapping portion by laser welding or the like. That is, by using the metal cover 8 also as a welding part, the burner BN can be easily fixed to the socket 7 while reducing the number of parts.

  Here, with the LCL shortened from the conventional length D1 = 27.1 mm to 18.0 mm (comparative example) and the metal cover 8 provided on the front end side of the flange portion 71, the LCL is D1 = 18. A lamp (Example) having a thickness of 0.0 mm was hermetically mounted on an automobile headlamp device, and a test was performed for continuous lighting for 1000 hours.

  As a result, in the lamp of the comparative example, the front end surface 711 of the flange portion 71 deteriorated and discolored, and clouding was confirmed inside the lens of the headlamp device. However, in the lamp of the example, the front end surface 711 deteriorated and discolored. It was not confirmed that the lens was cloudy. As a result, considering that the temperature of the light emitting section 11 during lighting of both lamps is about 900 ° C. and the amount of ultraviolet radiation is almost the same, only the front end face 711 is deteriorated due to the shortening of the LCL. It means that. That is, when the flange portion 71 is viewed from the light emitting portion 11 as in the lamp of the embodiment, the flange portion 71 is covered with the metal cover 8 so that almost all of the front end surface 711 is hidden. The deterioration of 71 can be sufficiently suppressed.

  Therefore, in the present embodiment, the lamp design of the lamp is short by adopting a simple structure in which the metal cover 8 is provided on the flange portion 71 of the socket 7 so as to cover the front end surface 711 thereof. In addition, deterioration of the flange portion 71 and the like can be suppressed.

  Further, the burner BN is provided with a metal band 6 having a protruding piece portion 61 protruding in a direction substantially perpendicular to the tube axis, and the protruding piece portion 61 and the protruding piece portion 84 of the metal cover 8 are welded. As a result, the metal cover 8 can also serve as a function of fixing the burner BN to the socket 7, so that the burner BN can be easily fixed to the socket 7 while reducing the number of parts.

(Second Embodiment)
FIG. 5 is a diagram for explaining a discharge lamp according to a second embodiment of the present invention. About each part of this 2nd Embodiment, the same part as each part of the discharge lamp of 1st Embodiment is shown with the same code | symbol, and the description is abbreviate | omitted.

  In the present embodiment, at least a part of the metal band 6 is positioned in the socket 7. Specifically, a portion of the projecting piece portion 84 that comes into surface contact with the projecting piece portion 61 is formed so as to be positioned on the rear end side with respect to the front end side surface of the socket 7, and The rear end side of the metal band 6 is positioned in the space of the socket 7 by welding.

  With this structure, the distance D2 between the light emitting portion 11 (interelectrode center) and the front end side portion of the metal band 6 can be separated as compared with the discharge lamp of the first embodiment having the same LCL. Become. Since the metal band 6 becomes higher in temperature as the distance D2 is shorter, when the metal band 6 and the metal cover 8 are mechanically connected, the heat is transmitted to the flange portion 71 and causes deterioration earlier. End up. Therefore, as in the present embodiment, the welding point between the metal band 6 and the metal cover 8 is arranged on the rear end side with respect to the front end side surface of the socket 7, and the distance between the light emitting unit 11 and the metal band 6 is increased, for example, By making the distance D2 15 mm or more, the effect of suppressing deterioration of the flange portion 71 can be enhanced.

(Third embodiment)
FIG. 6 is a diagram for explaining a discharge lamp according to a third embodiment of the present invention.

  In the present embodiment, a tongue piece 85 protruding in the direction of the metal band 6 is formed on the metal cover 8 instead of the projection piece 84 as shown in FIG. 7, and the tube axis of the tongue piece 85 and the metal band 6 is formed. The surface parallel to the surface is welded. Even with this structure, the same effects as those of the first embodiment can be obtained.

(Fourth embodiment)
FIG. 8 is a diagram for explaining a discharge lamp according to a fourth embodiment of the present invention.

  In the present embodiment, a plurality of spacers 9 made of a metal such as stainless steel are provided on the front end surface 711 of the flange portion 71 (for example, four at intervals of 90 degrees), so that a space is formed between the front end surface 711 and the metal cover 8. 10 is formed. Since the space 10 can reduce the amount of heat transferred from the metal cover 8 that has become high temperature during lighting to the flange portion 71, deterioration of the flange portion 71 can be suppressed. In addition, since the space 10 is formed, a predetermined notch or the like is provided on the front end surface of the metal cover 8 so that the reflector can be attached to and detached from the reflector having a lock member on the back side as in Patent Document 5. It can also be a lamp.

  The length D3 of the space 10 (the distance between the front end surface 711 and the metal cover 8) D3 is 0.1 mm to 1.0 mm, particularly 0.3 mm to 0, considering deterioration suppression of the flange portion 71 and the fixing strength of the metal cover 8. .8 mm is desirable. In addition, as for the spacer 9, you may make it substitute a part of flange part 71 like FIG.

  Although several embodiments have been described above, the present invention is not limited to the above, and may be modified as follows, for example.

  The socket 7 may be a circuit component having a flange portion 71 on the front end side as shown in FIG. In short, the socket 7 is an instrument for mechanically and electrically connecting the burner BN, and may have a structure having a flange portion 71 on the front end side.

  The potch portion may be formed on the front end surface 711 as a part of the flange portion 71. In this case, if a hole is formed in a part of the metal cover 8 and the potted portion is taken out from the hole, the measurement reference point such as LCL can be obtained as in the first embodiment. Thus, when the potch portion is formed by molding, the variation in height can be reduced, so that various dimensions can be measured accurately.

  The metal cover 8 is not limited to stainless steel but may be iron, stainless steel, nickel, or the like. That is, any material having excellent heat resistance and workability can be used for the metal cover 8. The same applies to the metal band 6. Further, as shown in FIG. 12, the metal cover 8 may be provided so as to cover almost the entire front end side of the socket 7 excluding a portion through which the burner BN passes, and in this configuration, a space for accommodating the burner BN. It is also possible to suppress the deterioration of the inner side of the socket 7 forming the.

  In the embodiment, the metal cover 8 is fixed to the socket 7 by adopting a structure in which the flange portion 71 is sandwiched or crimped by the outer fixing portion 83. However, the present invention is not limited to this. May be. A plurality of recesses may be formed on the back side of the flange portion 71, and the outer fixing portion 82 may be fitted into these recesses. Further, as shown in FIG. 13A, a metal piece 86 may be disposed so as to be in surface contact with each outer fixing portion 83, and each outer fixing portion 83 may be welded to the metal piece 86. Further, as shown in FIG. 13 (b), an arc-shaped metal piece 86 is formed in a certain outer fixing portion 83, folded, and brought into surface contact with the adjacent outer fixing portion 83, and then the overlapping portion is welded. It may be. Alternatively, as shown in FIG. 13C, a metal piece 86 may be embedded in the socket 7, and each outer fixing portion 83 may be brought into surface contact with the metal piece 86 and then the overlapping portion may be welded. If these structures are adopted, the metal cover 8 can be further prevented from being detached from the socket 7.

BN burner 1 Inner tube 11 Light emitting portion 5 Outer tube 6 Metal band 61 Projection piece 7 Socket 71 Flange portion 711 Front end surface 8 Metal cover 84 Projection piece

Claims (3)

A discharge lamp comprising: a burner provided with a light emitting part; and a socket for holding the burner so as to position the light emitting part on the front end side,
The discharge lamp according to claim 1, wherein the socket includes a flange portion on a front end side, and a metal cover is provided on the flange portion so as to cover a surface on the front end side.   The burner is provided with a metal band so as to hold an outer peripheral surface thereof, and the metal band includes a protruding piece portion protruding in a direction substantially perpendicular to the tube axis, and the protruding piece portion is the metal piece. The discharge lamp according to claim 1, wherein the discharge lamp is welded to the cover.   The discharge lamp according to claim 1, wherein a space is provided between the front end surface of the flange portion and the metal cover.

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