JP2007324054A - Thermal switch and high-pressure discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Bi-thermal switch capable of narrowing fluctuation ranges of a pressing force P of a movable contact to a fixed contact in the case of mass production. <P>SOLUTION: The thermal switch is provided with an insulator 15 to form a support body, a pair of conductors 16, 17 supported with a prescribed spacing by the insulator, a bimetal plate 19 of which one end part is joined/fixed by one conductor and supported in parallel with the insulator, the movable contact 20 installed at the other end part of the bimetal plate, and the fixed contact 18 installed at the other conductor and faced with the movable contact. The conductor 17 to which the bimetal plate is joined has a bent L-shape, a fixed piece Y formed by one side of the L-shape is supported by the insulator, one end part of the bimetal plate is joined to an adjustment piece X formed by the other side, and so that a prescribed pressing force P will act between the movable contact and the fixed contact, the conductor is plastically deformed and the adjustment piece forms a prescribed angle α to the fixed piece. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermally responsive switch using a bimetal, and more particularly, to a configuration of a thermally responsive switch suitable as a switching element constituting an outer tube built-in type starter for a high pressure discharge lamp.

  In the energy saving era, new high-efficiency metal halide (MH) lamps or high-pressure sodium (NH) lamps are used for indoor and outdoor lighting in place of the relatively low-efficiency conventional high-pressure mercury lamp in the field of high-pressure discharge lamps. Has been popularized.

  Conventional high-pressure mercury lamps are started with a commercial power supply voltage of 100 V or 200 V by a simple means of attaching an auxiliary electrode adjacent to one of the main electrodes at both ends of the quartz arc tube. On the other hand, MH / NH lamps are classified into the following two types from the starting system.

  Type (1) requires a starting device for applying a high voltage pulse of 1.5 to 3.5 kV for lamp starting, and this occupies most of the MH / NH lamp. In this case, in addition to the starting device, for example, an MH lamp made of a quartz arc tube is provided with an auxiliary electrode similar to a high-pressure mercury lamp. For example, in an NH lamp, a starting auxiliary conductor for assisting lamp starting may be attached to the outer wall of the arc tube. In order to turn on the lamp of type (1), a system in which a starter is provided in a dedicated ballast has been developed. Usually, the starter is built in an outer bulb glass bulb of the lamp. Are widely used in combination with a relatively simple copper-iron type reactance ballast. This is characterized by a relatively low overall system cost.

  For type (2), neon / argon penning is enclosed as a rare gas for starting auxiliary to the arc tube without using an extra starting device, and this is combined with at least one of auxiliary electrode and auxiliary starting conductor. To start the lamp.

  In any of the above-mentioned two types of lamps having different starting methods, generally, a bimetal thermal responsive switch using bimetal (hereinafter abbreviated as Bi-thermal responsive switch) performs the following different functions: It is incorporated in the outer tube glass bulb.

  First, the outer tube built-in type starter in type (1) is basically composed of a series circuit of a current interrupting switching element, a starting element opening switching element, and a current limiting resistor. Connected in parallel to the arc tube of the lamp. As an operation at the time of starting, first, the arc tube is started by the high-pressure pulse induced in the reactance ballast by the opening / closing operation of the “current blocking switching element”, and after starting the lamp, the “starting device opening switching element” is turned off. In operation, the starting device is released from the lighting circuit. In this case, in addition to so-called glow switches and ferroelectric ceramic capacitors having non-linear characteristics, Bi-thermally responsive switches are also used in particular for NH lamps and the like as switching elements for interrupting current. In addition, as a starter opening switching element, a Bi-thermally responsive switch is mainly used (for example, see Patent Document 1).

  In addition, both the auxiliary electrode and the starting auxiliary conductor provided in both types (1) and (2) are released from the lighting circuit by the switching element OFF operation in steady lighting after starting the lamp, and are maintained in a so-called floating potential state. Need to be drunk. That is, when the auxiliary electrode sealed at the tube end of the quartz arc tube is in an unreleased state, a so-called ionic current is induced between the main electrode and the auxiliary electrode lead wire at the tube end, thereby Damage to the edge occurs. In addition, when the starting auxiliary conductor attached to the outer wall of the arc tube is in an unreleased state, the luminescent material sealed in the arc tube is lost to the outside of the tube. In this case as well, a Bi-thermally responsive switch is mainly used as a “switching element for opening the auxiliary electrode and the starting auxiliary conductor” (see, for example, Patent Document 1).

  A Bi-thermally responsive switch is basically composed of a bimetal plate that is a thermally responsive component and a pair of conductors connected via an insulator connected in parallel to both ends thereof (for example, non-patent document). 1).

  FIG. 6 shows the configuration of a typical Bi-thermally responsive switch according to the prior art, which has been used, for example, in a type (1) MH lamp as a starting device and a switching element for opening the auxiliary electrode. (A) is a front view, (b) is a plan view. This Bi-thermally responsive switch 30 has a cylindrical insulator 31 made of glass, and an L-shaped molybdenum (Mo) lead bar 32 at both ends thereof, and a molybdenum (Mo) lead bar that also functions as a fixed contact. 33 are respectively sealed and fixed. A rectangular bimetal plate 34 is joined and fixed to the open end side of the Mo lead rod 32 by spot electric welding at one end 34 a so as to be parallel to the insulator 31. A tungsten (W) pin 35 that functions as a movable contact is joined and fixed to the other end 34b of the bimetal plate 34 by the same welding. Since the W pin 35 functions as a movable contact with respect to the fixed contact of the Mo lead rod 33, the W pin 35 is fixed to the Mo lead rod 33 in a state where a specific pressing force P is applied at room temperature.

  For example, as shown in FIG. 6B, the application of the pressing force P in the manufacturing process of the Bi-thermally responsive switch 30 is a separation distance G between the W pin 35 that is a movable contact and the Mo lead rod 33 that is a fixed contact. Is done by adjusting.

Note that the Bi-thermally responsive switch used as a switching element for other functions also has a basic configuration in accordance with the Bi-thermally responsive switch 30 shown in FIG.
Japanese Utility Model Publication No. 58-19816 National Technical Report, Vol23 No.4, August 1977

  The inventors of the present invention have analyzed the starting operation characteristics of the Bi-thermally responsive switch according to the prior art that has been used as various switching elements in the MH / NH lamp, and found the following problems.

  The biggest problem is that, for example, when the Bi-thermally-actuated switch 30 in FIG. 6 is mass-produced as a switching element for a starter or the like, the pressing force P of the W pin 35 that is a movable contact with respect to the Mo lead rod 33 that is a fixed contact. The fluctuation range is relatively large, for example, 0.20 ± 0.09 Newton. This was thought to have an unfavorable effect on the lifetime characteristics as well as the (re) starting characteristics of the lamp. That is, if the pressing force P becomes too low, for example, the so-called lamp restart time immediately after the lamp is extinguished becomes longer than the specification range, and the lamp may not start in application as a current interrupting switching element. On the other hand, if the pressing force P becomes too high, for example, the opening time of the auxiliary electrode or the starting auxiliary conductor after starting the lamp becomes too long, and the end of the arc tube due to the ionic current in the long-term lamp aging or the disappearance of the luminescent substance. Will be a concern.

  The increase in the fluctuation range of the pressing force P in mass production is due to the fact that the pressing force application in the final process of each Bi-thermally-actuated switch is due to human work. This can be attributed to the configuration of a conventional Bi-thermally responsive switch in which it is difficult to apply a pressing force by a mechanical mechanism.

  Another problem is that in the conventional Bi-thermally responsive switch 30, the pressing force P gradually decreases due to long-term lamp aging with a low generation rate. This occurs particularly when the weld strength at the joint between the bimetal plate 34 and the Mo lead rod 33 is weak. In other words, the joint is subjected to stress due to repeated opening and closing operations of the bimetal plate 34 during long-term lamp aging, and partially peels off. This is also basically the configuration of the Bi-thermally responsive switch 30. It can be said that it originates in itself.

  The present invention has been made in view of the above situation, and an object thereof is to provide a Bi-thermally responsive switch capable of narrowing the fluctuation range of the pressing force P of the movable contact with respect to the fixed contact in mass production. To do. It is another object of the present invention to provide a Bi-thermally responsive switch having a configuration that can reliably prevent a decrease in pressing force P during long-term lamp aging when used in a high pressure discharge lamp.

  It is another object of the present invention to provide a high pressure discharge lamp having improved (re) starting and life characteristics by using such a Bi-thermally responsive switch.

  The thermally responsive switch of the present invention includes an insulator that forms a support, a pair of conductors supported by the insulator at a predetermined interval, and one end joined to and fixed to one of the conductors. A bimetal plate supported in parallel with the insulator, a movable contact provided on the other end of the bimetal plate, and a fixed contact provided on the other conductor and facing the movable contact, A predetermined pressing force P is applied between the movable contact and the fixed contact, and in accordance with the thermal response of the bimetal plate, a force that makes the movable contact and the fixed contact contact or separate from each other acts to perform an opening / closing operation. .

  In order to solve the above-mentioned problem, the conductor to which the bimetal plate is bonded is a bent L-shape, and a fixed piece formed by one side of the L-shape is supported by the insulator, and the other side One end of the bimetal plate is joined to the adjustment piece formed by the step, and the conductor is plastically deformed so that the predetermined pressing force P acts between the movable contact and the fixed contact. The piece forms a predetermined angle α with respect to the fixed piece.

  According to the thermally responsive switch of the present invention having the above-described configuration, it is possible to reliably perform the operation of adjusting the adjustment piece so as to have a predetermined angle α with respect to the fixed piece by plastic deformation of the conductor. The fluctuation range of the pressing force P of the movable contact with respect to the fixed contact in mass production can be significantly reduced.

  In the thermally responsive switch of the present invention, the conductor adjustment piece is bent so as to form a double piece, and one end of the bimetal plate is sandwiched between the double pieces of the adjustment piece. It is preferable that it is bonded and fixed.

  With this configuration, it is possible to obtain a thermally responsive switch that reliably prevents a decrease in the pressing force P during long-term lamp aging.

  In a high pressure discharge lamp in which a starting device including a switching element is built in an outer tube bulb, it is preferable that the switching element is constituted by a thermally responsive switch having any one of the above configurations. Thereby, a high-quality high-pressure discharge lamp with improved (re) starting and life characteristics is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 shows an entire assembly structure of a 400 W MH lamp 5 with a built-in starter using a Bi-thermally responsive switch according to an embodiment of the present invention.

  In the arc tube 1, the envelope is made of quartz, a pair of tungsten main electrodes 2 and 3 are arranged at both ends of the tube, and an auxiliary electrode 4 is arranged near one of the main electrodes 2 via a molybdenum foil. Each is hermetically sealed. In the tube, Sc—Na metal halide as a luminescent material and argon Ar as a start assisting rare gas are sealed at 5 kPa.

The arc tube 1 and the starting device 6 having the above configuration are held by a pair of lead wires 7, 8 and the like and assembled in the outer tube glass bulb 9 to constitute the MH lamp 5. Inside the tube of the outer tube glass bulb 9, nitrogen N ₂ is sealed at 47 kPa, and a base 10 is attached to the end of the tube.

  FIG. 2 shows a lighting circuit configuration of the MH lamp 5 by a combination of the starting device 6 incorporated in the MH lamp 5 and the copper iron type reactance stabilizer 11. The starting device 6 is composed of a series circuit of a glow switch 12 that is a switching element for cutting off a current, a Bi-thermally responsive switch 13 that is a switching element for opening the starting device, and a resistor R1 for limiting the current. Connected in parallel. The auxiliary electrode 4 of the arc tube 1 is connected to an intermediate point a of the series circuit of the starting device 6 through a current limiting resistor R2, where the Bi-thermally responsive switch 13 is connected to the auxiliary electrode 4. It also functions as an opening switching element.

  As an operation of the starter 6 at the time of starting the lamp, first, when the glow switch 12 is activated by applying a power supply voltage from the AC power supply 14 (200 V / 220 V), the reactance ballast 11 is switched to 0 by the current interruption by the switching operation of the contact. A high voltage pulse voltage of .9 to 2.0 kV is induced, and the action of this and the auxiliary electrode 4 starts discharge between the main electrodes 2 and 3 of the arc tube 1. After the lamp is started, the glow switch 12 becomes inoperative because the applied voltage is greatly lowered, and the contact opening / closing operation is stopped. Next, after a specific elapsed time from the start of discharge, the Bi-thermally responsive switch 13 is heated by heat radiation from the arc tube 1 and is turned off. As a result, the starting device 6 is released from the lamp lighting circuit, and the auxiliary electrode 4 is also shifted to the floating potential state. In the subsequent steady lighting of the lamp, the Bi-thermal response switch 13 is maintained in the OFF state. Further, in the so-called lamp restart immediately after the lamp is turned off, the Bi-thermally responsive switch 13 is turned on by cooling over a specific time, and the operation of the starter 6 is resumed.

  The MH lamp 5 is characterized by the improved Bi- in the embodiment of the present invention as a switching element for opening the starting device of the starting device 6, instead of the Bi-thermally responsive switch 30 having the conventional structure shown in FIG. That is, a thermally responsive switch 13 is used. In the Bi-thermally-responsive switch 13, the fluctuation range of the pressing force P of the movable contact with respect to the fixed contact in mass production is greatly narrowed, thereby obtaining a high-quality MH lamp 5 with stable (re) starting and life characteristics. .

  The Bi-thermally responsive switch 13 in the present embodiment is manufactured in two stages, that is, a component assembly process and a subsequent pressing force application process. In the following, the components of the Bi-thermally responsive switch 13 in the present embodiment and the overall configuration in each process will be described in detail sequentially.

  FIG. 3A shows each component constituting the Bi-thermally responsive switch 13, and FIG. 3B shows the entire configuration of the Bi-thermally responsive switch 13 assembled by the component assembling process. In FIG. 3A, the insulator 15, the bimetal plate 19, and the movable contact W pin 20 are illustrated in a planar shape, and the lead plates 16, 17 and the fixed contact W pin 18 are illustrated in a front shape. ing.

  As shown in FIG. 3A, the Bi-thermally responsive switch 13 includes an insulator 15 having a U-shaped planar shape made of ceramic, and a Mn—Ni (manganese. Nickel) lead plates 16 and 17, a fixed contact W (tungsten) pin 18, a rectangular bimetal plate 19, and a movable contact W (tungsten) pin 20. The cross section of the insulator 15 is substantially square. The horizontal sides X and vertical sides Y of the lead plates 16 and 17 are substantially perpendicular.

  These parts are assembled as shown in FIG. That is, the paired Mn—Ni lead plates 16 and 17 are fixed to the opposite side portions 15 a and 15 b of the U-shaped insulator 15, respectively. The Mn-Ni lead plates 16 and 17 are bent so that the vertical sides Y of the Mn-Ni lead plates 16 and 17 are fitted to both side portions 15a and 15b of the insulator 15, and are joined by spot electric welding after being fitted. It is fixed with. That is, the insulator 15 functions as a support for supporting the Mn—Ni lead plates 16 and 17 at a predetermined interval. The vertical sides Y of the Mn—Ni lead plates 16 and 17 form a fixed piece, and the horizontal sides X have open ends.

  A fixed contact W pin 18 is joined and fixed to the lateral X surface of the Mn—Ni lead plate 16 by spot electric welding. The bimetal plate 19 is disposed so as to be substantially parallel to the bottom 15c of the insulator 15, and one end 19a of the bimetal plate 19 is joined and fixed to the lateral X surface of the Mn-Ni lead plate 17 by spot electric welding. The The lateral side X of the Mn—Ni lead plate 17 supports the bimetal plate 19 and forms an adjustment piece for adjusting the angle as described later. The movable contact W pin 20 is joined and fixed to the other end 19b of the bimetal plate 19 by the same welding. The movable contact W pin 20 is disposed so as to form a substantially cross shape with respect to the fixed contact W pin 18 fixed to the Mn—Ni lead plate 16.

  Examples of dimensions of each part are as follows. The insulator 15 has a bottom portion T20 mm × both side portions H8 mm × cross section 2 mm □. The Mn—Ni lead plate 16 has a horizontal side X 8.0 mm × vertical side Y 6.0 mm × width 2.5 mm × thickness 0.3 mm, the Mn—Ni lead plate 17 has a vertical side Y 7.6 mm, and the others are Mn—Ni. It is the same as the lead plate 16. The fixed contact W pin 18 has a pin length of 6 mm and a diameter of 0.8 mm. The bimetal plate 19 is JIS C 2530, plate length 20 mm × width 5 mm × thickness 0.2 mm. The movable contact W pin 20 has a pin length of 6 mm and a diameter of 0.8 mm.

  As shown in FIG. 4A (the same state as FIG. 3B), the main point of the configuration of the Bi-thermally responsive switch in the component assembling process is that the bimetal plate 19 fixes the movable contact W pin 20. The pressing force P against the contact W pin 18 is substantially zero, and is welded and fixed to the X side of the L-shaped Mn—Ni lead plate 17 (the horizontal side X and the vertical side Y are substantially right angles). . Accordingly, no stress is applied to the bimetal plate 19 and the shape thereof is kept flat before being assembled.

  FIG. 4B schematically shows the Bi-thermally responsive switch 13 having the final configuration obtained as a result of the deformation of the bimetal plate 19 in the pressing force application process. The feature of this configuration is that a fixed Mn− at one end 19a of the bimetal plate 19 is applied in order to apply a specific pressing force P between the movable contact W pin 20 and the fixed contact W pin 18 in the Bi-thermally responsive switch 13. That is, the lateral side X of the Ni lead plate 17 is expanded at a specific angle α with respect to the longitudinal side Y by a mechanical mechanism and is plastically deformed. Stress is applied to the bimetal plate 19 in this final configuration due to plastic deformation of the Mn—Ni lead plate 17, and the bimetal plate 19 is deformed from a flat shape in the component assembling process to a gentle arc surface shape. Thereby, in the Bi-thermally responsive switch 13 of the final configuration, the fluctuation range of the pressing force P of the movable contact W pin 20 with respect to the fixed contact W pin 18 in mass production can be significantly narrowed. By using this Bi-thermally responsive switch 13, a high-quality high-pressure discharge lamp with stable (re) starting and life characteristics can be obtained.

  In order to confirm the effect of the above configuration, the angle α formed by expanding the horizontal side X of the Mn—Ni lead plate 17 with respect to the vertical side Y in the pressing force applying step is set to 6 °, and Bi−heat A mass production trial of the responsive switch 13 was performed, and the fluctuation range of the pressing force P was measured. As a result, it was confirmed that the fluctuation range of the pressing force P of the Bi-thermally responsive switch 13 can be suppressed to a relatively narrow range of 0.20 ± 0.03 Newton. This is significantly narrower than the fluctuation range 0.20 ± 0.09 Newton of the pressing force P in the case of the Bi-thermally responsive switch 30 having the conventional structure shown in FIG.

  In addition, the MH lamp 5 built in the starter 6 using the Bi-thermally responsive switch 13 according to the embodiment of the present invention was mass-produced and prototyped, and the start operation characteristics were measured. At the same time, as a comparative example, an MH lamp 5 'in which only the Bi-thermally responsive switch 13 is replaced with the conventional Bi-thermally responsive switch 30 of FIG. The results were as follows.

  (1) In the case of the MH lamp 5 of the embodiment, the fluctuation range of the opening time te of the starting device 6 and the auxiliary electrode 4 due to the OFF operation of the Bi-thermally responsive switch 13 after starting the lamp is 1.0 ± 0.2 min. there were. On the other hand, the te fluctuation range in the case of the MH lamp 5 'of the comparative example was 1.3 ± 0.4 min.

  (2) In the case of the MH lamp 5 of the example, the fluctuation range of the restart time tr due to the ON operation of the Bi-thermally responsive switch 13 immediately after the lamp is turned off was 9.0 ± 1.0 min. On the other hand, the tr fluctuation width in the case of the MH lamp 5 'of the comparative example was 8.5 ± 2.0 min.

  As described above, it was confirmed that both the fluctuation range of the opening time te and the fluctuation range of the restart time tr can be suppressed to a significantly narrower range in the MH lamp 5 of the embodiment than in the MH lamp 5 ′ of the comparative example. .

  Next, regarding the Bi-thermally responsive switch 13 in this embodiment, whether or not the pressing force P gradually decreases with long-term lamp aging as in the case of the conventional Bi-thermally responsive switch 30 is indirectly determined by MH. The change was examined from the change in the restart time tr with the long-term lamp aging of the lamp 5. As a result, for one of the 50 aging lamps, it was observed that the restart time tr changed from the initial value of 6.5 min to 7.6 min at 5000 hrs aging, which was the Bi− used for the lamp. It was determined that this was due to a decrease in the pressing force P of the thermal response switch 13.

  In order to cope with this experimental result, a means for preventing the change of the pressing force P accompanying the long-term lamp aging was examined. As a result, it has been found that the structure of the Mn—Ni lead plate 17 to which the one end 19a of the bimetal plate 19 is fixed may be improved with respect to the Bi-thermally responsive switch 13 in the present embodiment as described below. .

  FIG. 5 is an enlarged view of the structure of the improved Mn—Ni lead plate 21 where the bimetal plate 19 is bonded and fixed. The feature of this configuration is that the lateral side X of the Mn—Ni lead plate 21 is double-folded to form a double piece portion 21a, and one end 19a of the bimetal plate 19 is sandwiched between the double lateral sides X. In other words, it is joined and fixed by spot electric welding. Thereby, the welding strength of the joint part of the bimetal plate 19 and the Mn—Ni lead plate 21 can be remarkably increased, and as a result, the change of the pressing force P accompanying the long-term lamp aging can be surely prevented. In fact, it was confirmed that the MH lamps that were mass-produced by the Bi-thermally responsive switch 22 using the Mn-Ni lead plate 21 were stable with almost no change in the restart time tr over the long-term lamp aging. did.

  As described above, the Bi-thermally-responsive switch used as a switching element in a starter or the like with a built-in outer tube of a high-pressure discharge lamp such as an MH / NH lamp has a configuration based on this embodiment. The variation range of the pressing force P of the movable contact with respect to the fixed contact in mass production of the thermally responsive switch can be greatly reduced. Further, it is possible to reliably prevent a decrease in the pressing force P during long-term lamp aging, and as a result, it is possible to improve (re) starting and life characteristics of the high-pressure discharge lamp.

  According to the present invention, a Bi-thermally responsive switch capable of narrowing the fluctuation range of the pressing force P of the movable contact with respect to the fixed contact is obtained, and the (re) starting and life characteristics are improved. Useful.

The figure which shows the whole assembly structure of the metal halide lamp using the Bi-thermally-responsive switch in one embodiment of this invention. A circuit diagram showing a lighting circuit configuration of a metal halide lamp using the Bi-thermally responsive switch (A) is a figure which shows each component of the same Bi-thermally responsive switch, (b) is a front view which shows the whole structure after a component assembly process. (A) is a front view which shows the state before the pressing force adjustment of the Bi-thermally responsive switch, (b) is a front view which shows the state after a bimetal plate deformation | transformation by pressing force adjustment. The front view of the principal part which shows the fixing method of the improved bimetal plate of the same Bi-thermally responsive switch The whole structure of the Bi-thermally responsive switch by a prior art is shown, (a) is a front view, (b) is a top view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arc tube 2, 3 Main electrode 4 Auxiliary electrode 5 Metal halide lamp 6 Starting device 7, 8 Lead wire 9 Outer tube glass bulb 10 Base 11 Copper iron type reactance ballast 12 Glow switch 13, 22 Bi-thermally-responsive switch 14 AC power supply DESCRIPTION OF SYMBOLS 15 Insulator 16, 17, 21 Mn-Ni lead plate 18 Fixed contact W pin 19 Bimetal plate 20 Movable contact W pin 21a Double piece part

Claims (3)

An insulator forming a support;
A pair of conductors supported by the insulator at a predetermined interval;
A bimetal plate having one end joined and fixed to one of the conductors and supported in parallel with the insulator;
A movable contact provided at the other end of the bimetal plate;
A fixed contact provided on the other conductor and facing the movable contact;
A predetermined pressing force P is applied between the movable contact and the fixed contact. As the bimetal plate is thermally activated, a force that makes the movable contact and the fixed contact contact or separate from each other acts to perform an opening / closing operation. In the heat responsive switch
The conductor to which the bimetal plate is bonded has a bent L-shape, and a fixed piece formed by one side of the L-shape is supported by the insulator, and the adjustment piece formed by the other side is added to the adjustment piece formed by the other side. One end of the bimetal plate is joined,
The conductive piece is plastically deformed so that the predetermined pressing force P acts between the movable contact and the fixed contact, and the adjustment piece forms a predetermined angle α with respect to the fixed piece. Thermally responsive switch.   The adjustment piece of the conductor is bent so as to form a double piece portion, and is joined and fixed in a form in which one end of the bimetal plate is sandwiched between the double piece portions of the adjustment piece. The heat responsive switch according to 1. In a high-pressure discharge lamp in which a starting device including a switching element is built in an outer bulb,
The high-pressure discharge lamp characterized in that the switching element is constituted by the thermally responsive switch according to claim 1 or 2.

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