JP5846504B2 - Ceramic metal halide lamp and manufacturing method thereof - Google Patents

Description

  The present invention relates to a ceramic metal halide lamp and a method for manufacturing the same, and more particularly to a configuration of an end portion of a discharge vessel.

  In recent years, ceramic metal halide lamps using a ceramic discharge vessel have become widespread. In the ceramic metal halide lamp, since the discharge vessel is made of ceramic such as translucent alumina, there is little deterioration of the discharge vessel due to the reaction with the encapsulated material, and the lamp life can be improved.

  A discharge vessel of a ceramic metal halide lamp includes a light-emitting portion having a substantially spheroid shape and narrow tubes (capillaries) on both sides thereof. Electrode systems are respectively attached to the thin tube portions. A seal portion is formed by sealing a gap between the narrow tube portion and the electrode system with a sealant. The inside of the discharge vessel is sealed by the seal portion, and an inert gas such as argon and a luminescent material are sealed.

  An electrode system typically has an electrode formed by a tungsten rod, a current supply conductor including a conductive cermet rod, and a lead formed by a conductive material. The electrode, current supply conductor, and lead wire are connected by butt welding.

  In the examples disclosed in Patent Documents 2, 3, and 4, the current supply conductor protrudes from the thin tube portion of the discharge vessel, and the weld portion between the current supply conductor and the lead wire is located outside the thin tube portion of the discharge vessel. In such a structure, a structure for reinforcing the welded portion is provided in order to prevent the welded portion from being broken. For example, Patent Document 2 describes an example of a reinforcing member obtained by winding a tungsten wire in a coil shape.

Special Table 2003-532259 JP2003-100254 JP 2002-367564 A JP 2012-043542 A

  In the example disclosed in Patent Document 1, the current supply conductor is housed inside the thin tube portion of the discharge vessel, and the current supply conductor and the welded portion of the lead wire are inside the thin tube portion of the discharge vessel. A part of the lead wire is housed inside the thin tube portion of the discharge vessel, and the remaining lead wire protrudes from the thin tube portion of the discharge vessel. In such a structure, no reinforcing member is provided in the welded portion. On the other hand, the lead wire is formed of a metal niobium rod having excellent malleability and ductility.

  However, even if the lead wire is made of metal niobium, it may break in the assembly process of the ceramic metal halide lamp. Even after the product is completed, it is conceivable that the lead wire may be disconnected due to vibration or impact during lamp transportation or continuous vibration or impact depending on the lamp installation location.

  An object of the present invention is to prevent a niobium lead wire protruding from a thin tube portion of a discharge vessel from being easily broken in a lamp manufacturing process and the like, and to improve the efficiency of the lamp manufacturing process. It is to provide a lamp and a manufacturing method thereof.

The inventor of the present application first investigated the cause of the niobium lead wire being easily broken. Niobium Nb is known to be relatively stable at room temperature, but embrittles by absorbing carbon, hydrogen, and the like at high temperatures. As described in Patent Document 3, in the process of forming the seal portion in the narrow tube portion of the discharge vessel, when the frit molded body melts, gas such as carbon monoxide CO, carbon dioxide CO ₂ may be generated. Are known. The inventor of the present application considered that the lead wire becomes brittle when the metal niobium absorbs these gases.

  Therefore, in order to avoid embrittlement of the lead wire, these gases may be removed in advance so that the lead wire does not absorb. The inventor of the present application diligently studied a method for removing these gases. The inventor of the present application has conceived of providing a gas absorbing member on a lead wire. That is, the gas generated by melting the frit molded body may be absorbed by a gas absorbing member provided on the lead wire before the lead wire absorbs it. Patent Document 3 describes that the stopper is made of niobium or tantalum in order to avoid generation of bubbles in the glass frit of the seal portion.

  The gas absorbing member may be made of any material that can absorb the gas generated by melting the frit molded body. However, the gas absorbing member is preferably made of niobium metal. The cause of the embrittlement of the lead wire is that the gas generated by melting the frit molded body is absorbed by the lead wire made of niobium. Therefore, it is efficient to absorb and remove such gas by a gas absorbing member made of niobium made of the same material. Furthermore, even if the type of gas generated by melting the frit molded body cannot be specified, it can be removed.

  The gas absorbing member is preferably made of the same metal as that constituting the lead wire, that is, metal niobium, but is made of another metal having a gas absorbing action equivalent to metal niobium, for example, tantalum. May be. Niobium and tantalum belong to Group 5 elements called semimetals and have similar chemical properties.

According to an embodiment of the present invention, a translucent outer tube, a discharge vessel having a light emitting portion and a thin tube portion, and an electrode system mounted on the thin tube portion of the discharge vessel, the electrode system comprising tungsten In a ceramic metal halide lamp configured to have an electrode, a current supply conductor, and a lead wire made of niobium,
The connecting portion between the current supply conductor and the lead wire is disposed inside the narrow tube portion, a part of the lead wire is disposed within the thin tube portion, and the remaining portion of the lead wire protrudes from the tip of the thin tube portion. A gas absorbing member that absorbs gas generated when a seal portion is formed in the narrow tube portion is mounted around the vicinity of the narrow tube portion of the protruding portion.

  According to this embodiment, in the ceramic metal halide lamp, the gas absorbing member may be constituted by a coil made of niobium or tantalum.

  According to this embodiment, in the ceramic metal halide lamp, the current supply conductor includes a halogen-resistant intermediate material and a conductive cermet rod, the tungsten electrode is connected to the halogen-resistant intermediate material, and the lead wire is connected to the conductive metal. It may be connected to a sex cermet bar.

  According to the present embodiment, in the ceramic metal halide lamp, the length of the seal portion formed with the sealing material in the narrow tube portion is equal to the dimension from the tip of the narrow tube portion to the inner end of the conductive cermet rod. Or larger.

  According to this embodiment, in the ceramic metal halide lamp, the lead wire may be connected to a stopper that isolates the gas absorbing member and the tip of the narrow tube portion.

According to an embodiment of the present invention, a translucent outer tube, a discharge vessel having a light emitting portion and a thin tube portion, a tungsten electrode provided on the thin tube portion, a current supply conductor, and an electrode having a niobium lead wire A method of manufacturing a ceramic metal halide lamp comprising:
A step of preparing a discharge vessel having a light emitting portion and a thin tube portion, and an electrode system having a niobium lead wire;
Attaching a gas absorbing member to the lead wire of the electrode system, and then attaching a frit molded body;
Inserting the electrode system into the capillary section;
Supporting the discharge vessel such that the central axis of the discharge vessel is vertical;
A melting step of heating and melting the frit molded body;
The molten frit flows into the narrow tube part while contacting the gas absorbing member, and when the gap between the inner surface of the thin tube part and the electrode system is filled, the melted frit is solidified to form a sealing material. And steps to
And have.

According to an embodiment of the present invention, a translucent outer tube, a discharge vessel having a light emitting portion and a thin tube portion, a tungsten electrode provided in the thin tube portion, a current supply conductor, and a lead wire made of niobium are provided. In the method of manufacturing a ceramic metal halide lamp, comprising: an electrode system in which the lead wire is connected to a stopper of two metal wires arranged so as to be orthogonal to the axis of the lead wire,
A discharge vessel having a light emitting portion and a thin tube portion, and a lead wire made of niobium, to which two metal wire stoppers arranged so as to be orthogonal to the axis of the lead wire are connected. An electrode system comprising:
Attaching a gas absorbing member to the lead wire of the electrode system, and then attaching a frit molded body;
Inserting the electrode system into the capillary section;
Supporting the discharge vessel so that the central axis of the discharge vessel is vertical, abutting the stopper and the end surface of the narrow tube portion, and abutting the stopper and the gas absorbing member;
A melting step of heating and melting the frit molded body;
The molten frit flows into the narrow tube portion from between the stoppers while contacting the gas absorbing member, and when the gap between the inner surface of the thin tube portion and the electrode system is filled, the molten frit is solidified. Forming a sealing material;
And have.

According to an embodiment of the present invention, in a method for manufacturing a ceramic metal halide lamp,
The gas absorbing member may be constituted by a coil made of niobium or tantalum.

  According to the present invention, the niobium lead wire protruding from the thin tube portion of the discharge vessel is prevented from being easily broken in the lamp manufacturing process and the like, and the ceramic metal halide can improve the efficiency of the lamp manufacturing process. A lamp and a method for manufacturing the lamp can be provided.

FIG. 1A is a diagram illustrating a configuration example of a ceramic metal halide lamp according to the present embodiment. FIG. 1B is a diagram illustrating a configuration example of a discharge vessel of a ceramic metal halide lamp according to the present embodiment. FIG. 1C is a diagram illustrating a configuration example of the seal portion of the thin tube portion of the discharge vessel of the ceramic metal halide lamp according to the present embodiment. FIG. 2A is an explanatory diagram for explaining a method of inserting an electrode system into a thin tube portion of a discharge vessel of a ceramic metal halide lamp according to the present embodiment. FIG. 2B is an explanatory view for explaining a method of inserting the gas absorbing member and the frit molded body into the lead wire of the electrode system of the ceramic metal halide lamp according to the present embodiment. FIG. 3 is a view for explaining a state in which the discharge vessel of the ceramic metal halide lamp according to the present embodiment is attached to the sealing device. FIG. 4 is an explanatory view illustrating an example of a sealing process for forming a seal portion of a thin tube portion of the discharge vessel of the ceramic metal halide lamp according to the present embodiment. FIG. 5 is a view showing an example of the structure of a frit molded body used for the seal portion of the thin tube portion of the discharge vessel of the ceramic metal halide lamp according to the present embodiment. FIG. 6A is a diagram illustrating an example of the structure of a gas absorbing member that was prototyped by the inventors of the present application. FIG. 6B is a diagram showing an example of the structure of a gas absorbing member that was invented by the inventors of the present application. FIG. 6C is a diagram showing an example of the structure of the gas absorbing member that was invented by the inventors of the present application. FIG. 7A is a diagram for explaining a method of bending a lead wire in a thin tube portion of a discharge vessel of a ceramic metal halide lamp performed by the inventors of the present application. FIG. 7B is a diagram for explaining a result of a bending test of a lead wire of a thin tube portion of a discharge vessel of a ceramic metal halide lamp performed by the inventor of the present application.

  Hereinafter, embodiments of a ceramic metal halide lamp according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  An outline of an example of the ceramic metal halide lamp according to the present embodiment will be described with reference to FIG. 1A. The ceramic metal halide lamp 100 includes a translucent outer tube 111, an end cap 112, and a discharge vessel 130 disposed substantially at the center of the translucent outer tube 111. The inside of the translucent outer tube 111 is maintained in a high vacuum at a pressure of 10 Pa or less. The ceramic metal halide lamp 100 is mounted vertically with the base 112 facing upward as shown.

  A translucent sleeve 108 is provided around the discharge vessel 130, and a metal frame 109 is provided outside thereof. A starter 110 is provided on the upper side of the discharge vessel 130. A getter 113 is attached to the upper end of the frame 109.

  The frame 109 is connected to the lower end mounting support plate 114 and the upper end stem 115 lead-in line, thereby fixing the position. The frame 109 serves not only as a position fixing member but also as a member for electrical connection, and supplies power from an external power supply system (not shown) to the discharge vessel 130 via an introduction line of the stem 115.

  The structure of the discharge vessel 130 will be described with reference to FIG. 1B. The discharge vessel 130 has a central light emitting portion 130C and narrow tube portions 130A and 130B on both sides thereof. The discharge vessel 130 of this example is a so-called integrated type in which a light-emitting portion 130C having a substantially spheroid shape and thin tube portions 130A and 130B on both sides thereof are integrally formed. However, the discharge vessel 130 may be formed by connecting separately manufactured narrow tube portions 130A and 130B on both sides of the light emitting portion 130C.

  Electrode systems 120a and 120b are mounted on the thin tube portions 130A and 130B, respectively. The electrode systems 120 a and 120 b include a tungsten electrode 123, a current supply conductor 122, and a lead wire 121. The lead wire 121 is composed of a metal niobium (Nb) rod. A tungsten coil is attached to the tip of the tungsten electrode 123. The tip of the tungsten electrode 123 is disposed in the light emitting part 130 </ b> C of the discharge vessel 130.

  The current supply conductor 122 includes a halogen-resistant intermediate material 122a and a conductive cermet rod 122b. The tungsten electrode 123, the current supply conductor 122, and the lead wire 121 are connected by butt welding. A gas absorbing member 131 is attached to the lead wire 121 protruding from the thin tube portions 130A and 130B. For example, the gas absorbing member 131 may be formed of coiled metal niobium. The material, shape, function, etc. of the gas absorbing member 131 will be described in detail later.

  Inside the discharge vessel 130, a luminescent material, mercury and an inert gas are enclosed. The inert gas is, for example, a rare gas, but is argon in this embodiment. When the ceramic metal halide lamp is turned on, the luminescent material is heated by the discharge in the discharge vessel 130, and a part thereof is evaporated and excited by the discharge to emit light. The remaining part of the luminescent material is pooled in the liquid phase in the coldest part at the bottom of the discharge vessel 130. A part of the liquid phase luminescent material evaporates, circulates inside the discharge vessel 130 by convection, and returns to the coldest part at the bottom. Such a cycle is repeated while the lamp is on.

  With reference to FIG. 1C, an example of the structure of the seal portion of the narrow tube portion 130A of the discharge vessel 130 will be described in detail. A current supply conductor 122 is disposed inside the narrow tube portion 130A. The current supply conductor 122 includes a halogen-resistant intermediate material 122a and a conductive cermet rod 122b. The halogen-resistant intermediate material 122a is formed of a halogen-resistant material that is not eroded by the metal halide sealed in the discharge vessel 130. For example, molybdenum may be used as the halogen resistant material. In the present embodiment, the halogen-resistant intermediate material 122a is formed by a molybdenum rod 122c and a molybdenum coil 122d wound around the molybdenum rod 122c. Various shapes are known as the structure of the halogen-resistant intermediate material 122a. For example, the halogen-resistant intermediate material 122a may be formed of a single molybdenum rod or a molybdenum rod and a molybdenum pipe surrounding it. Furthermore, the halogen-resistant intermediate material 122a may be omitted, and a part of the tungsten electrode 123 (FIG. 1B) may be covered with a molybdenum coil or a molybdenum pipe.

  The conductive cermet rod 122b is formed by mixing and sintering alumina and molybdenum. The lead wire 121 is connected to the tip of the conductive cermet rod 122b. The connecting portion between the lead wire 121 and the conductive cermet rod 122b is disposed inside the tip of the thin tube portion 130A. The lead wire 121 protrudes from the tip of the thin tube portion 130A, and a gas absorbing member 131 is mounted around the protruding portion. A stopper 121 a is connected to the lead wire 121. The stopper 121a is in contact with the tip of the narrow tube portion 130A. The material, shape, function, etc. of the stopper 121a will be described in detail later.

  A sealing material 135 is filled in a gap between the gas absorbing member 131 and the lead wire 121. Sealing materials 135 are filled in the gaps between the inner surface of the thin tube portion 130A and the lead wire 121 and the conductive cermet rod 122b. A part of the gap between the inner surface of the thin tube portion 130A and the halogen-resistant intermediate material 122a is also filled with the sealing material 135.

A process of inserting the electrode system 120a of the narrow tube portion 130A of the discharge vessel 130 will be described with reference to FIG. 2A. First, the gas absorbing member 131, the frit molded body 132, and the electrode system 120a are prepared. In the present embodiment, the gas absorbing member 131 is formed in a coil shape, and the frit molded body 132 is constituted by a ring member formed by mixing alumina Al ₂ O ₃ , silica SiO _2, and display Dy ₂ O ₃ . The electrode system 120a includes a tungsten electrode 123, a current supply conductor 122, and a lead wire 121 made of metallic niobium. The current supply conductor 122 includes a halogen-resistant intermediate material 122a and a conductive cermet rod 122b. A stopper 121 a is attached to the lead wire 121. The gas absorbing member 131 and the frit molded body 132 are attached to the lead wire 121 in this order. Next, when the electrode system 120a is inserted into the thin tube portion 130A, the stopper 121a contacts the tip of the thin tube portion 130A.

  Here, first, the gas absorbing member 131 and the frit molded body 132 are attached to the lead wire 121, and then the electrode system 120a is inserted into the narrow tube portion 130A. This order is convenient. For example, first, the electrode system 120 a may be inserted into the narrow tube portion 130 </ b> A, and then the gas absorbing member 131 and the frit molded body 132 may be attached to the lead wire 121.

  A method of mounting the gas absorbing member 131 and the frit molded body 132 on the lead wire 121 of the electrode system 120a will be described with reference to FIG. 2B. A pair of stoppers 121 a is connected to the lead wire 121. In this embodiment, the stopper 121a is composed of two metal wires, and is arranged so as to be orthogonal to the axis of the lead wire 121 so as to sandwich the lead wire 121. The stopper 121a is connected to the lead wire 121 by resistance welding or spot welding.

  When the gas absorbing member 131 is attached to the lead wire 121, the gas absorbing member 131 comes into contact with the stopper 121a and stops at that position. Next, the frit molded body 132 is attached to the lead wire 121. The frit molded body 132 abuts on the gas absorbing member 131 and stops at that position.

  When the electrode system 120a is attached to the narrow tube portion 130A of the discharge vessel 130, it is attached to a sealing device (not shown). The sealing device typically includes a chamber that forms a sealed space and a heater provided therein, and the heater is configured to locally heat the seal portion of the narrow tube portion 130A of the discharge vessel 130. Yes. Detailed description of the sealing device is omitted.

  FIG. 3 shows a part of the discharge vessel 130 held in a sealing device (not shown). The discharge vessel 130 is held by a sealing device so that its central axis is vertical. An electrode system 120a is attached to the upper narrow tube portion 130A. The electrode system 120 a includes a tungsten electrode 123, a current supply conductor 122, and a lead wire 121. A part of the lead wire 121 is disposed in the narrow tube portion 130A, and the remaining portion protrudes from the narrow tube portion 130A. A gas absorbing member 131 and a frit molded body 132 are attached to a lead wire protruding from the thin tube portion 130A. As illustrated, the gas absorbing member 131 is disposed on the lower side, and the frit molded body 132 is disposed on the gas absorbing member 131.

  A stopper 121a connected to the lead wire 121 is disposed on the tip of the thin tube portion 130A. The stopper 121 a defines the insertion length of the electrode system 120 a inserted into the discharge vessel 130. That is, the stopper 121a defines the position of the electrode disposed in the light emitting unit 130C of the discharge vessel 130. The total weight of the electrode system 120a, the gas absorbing member 131, and the frit molded body 132 is supported by the stopper 121a.

  A halogen-resistant intermediate material 122a and a conductive cermet rod 122b are disposed inside the narrow tube portion 130A. A connecting portion between the conductive cermet rod 122b and the lead wire 121 is disposed inside the narrow tube portion 130A.

  A slight gap is formed between the gas absorbing member 131 and the lead wire 121. The outer diameters of the lead wire 121, the conductive cermet rod 122b, and the halogen resistant intermediate material 122a are smaller than the inner diameter of the narrow tube portion 130A. Accordingly, a gap is formed between the lead wire 121, the conductive cermet rod 122b, the halogen-resistant intermediate material 122a, and the thin tube portion 130A.

  The outer diameter of the conductive cermet rod 122b is slightly smaller than the outer diameter of the halogen-resistant intermediate material 122a. Therefore, the gap between the narrow tube portion 130A and the conductive cermet rod 122b is slightly larger than the gap between the narrow tube portion 130A and the halogen-resistant intermediate material 122a.

  A heater (not shown) disposed around the thin tube portion 130A is operated. The frit molded body 132 is locally heated and melted by the heater. The molten frit is caused by gravity and capillary phenomenon, a gap between the gas absorbing member 131 and the lead wire 121, a gap between the inner surface of the narrow tube portion 130A and the lead wire 121, and between the inner surface of the narrow tube portion 130A and the conductive cermet rod 122b. And further enters a part of the gap between the inner surface of the narrow tube portion 130A and the halogen-resistant intermediate material 122a. A sealing material is formed by solidifying the molten frit. Here, a portion where the sealing material is formed in the thin tube portion 130A is referred to as a sealing portion (sealing portion).

  The thin tube portion 130A of the discharge vessel 130 includes a seal portion (sealing portion) and a non-sealing portion (non-sealing portion). The total length of the thin tube portion 130A is L, the length of the seal portion, that is, the seal length is L1, and the length of the non-seal portion is L2. Let Ln be the dimension of the portion of the lead wire 121 inserted into the narrow tube portion 130A. The dimension in the axial direction of the conductive cermet rod 122b is Ls, and the dimension in the axial direction of the halogen-resistant intermediate material 122a is Lh. L = L1 + L2 = Ln + Ls + Lh.

  If the length L1 of the seal portion is short, the seal is insufficient or the seal is poor. Further, the sealing material of the sealing portion is gradually eroded by the metal halide sealed in the arc tube during lamp operation. In order to meet the demand for longer lamp life (20,000 hours or longer), the seal length L1 is preferably 4 mm or longer.

  In the present embodiment, the length L1 of the seal portion is equal to or larger than the dimension from the tip of the narrow tube portion 130A to the lower end of the conductive cermet rod 122b. That is, L1 ≧ Ln + Ls. Of the seal portion, the length of the portion formed in the portion of the halogen-resistant intermediate material 122a is Lm. L1 = Ln + Ls + Lm where Lm ≧ 0.

  If the dimension Lm is too long, cracks may occur in the thin tube portion 130A due to the difference in thermal expansion coefficient between the halogen-resistant intermediate material 122a and the thin tube portion 130A. Therefore, this dimension Lm is about 1.5 mm at most. For example, the outer diameter of the thin tube portion 130A is 3 mm, and the dimension from the tip of the thin tube portion 130A to the lower end of the conductive cermet rod 122b is Ln + Ls = 4 mm. In this case, the seal length L1 is L1 = 4.0 to 5.5 mm.

  Let Lg be the dimension from the upper end of the gas absorbing member 131 to the tip of the narrow tube portion 130A. The dimension in the axial direction of the gas absorbing member 131 is h, and the height in the axial direction of the stopper 121a, that is, the wire diameter is ds. Lg = h + ds. The dimension Lg is Lg = 2 to 4 mm.

  An example of a method for forming a seal portion (sealing portion) on the narrow tube portion 130A of the discharge vessel 130 according to the present embodiment will be described with reference to FIG. In step 101, a gas absorbing member 131, a frit molded body 132, and an electrode system 120a are prepared. As shown in FIG. 2A, the electrode system 120a includes a tungsten electrode 123, a halogen-resistant intermediate material 122a, a conductive cermet rod 122b, and a lead wire 121 made of metallic niobium.

  In step 102, the gas absorbing member 131 and the frit molded body 132 are attached to the lead wire 121 of the electrode system 120a in this order. As shown in FIG. 2B, the gas absorbing member 131 abuts on a stopper 121 a provided on the lead wire 121. The frit molded body 132 is disposed so as to contact the gas absorbing member 131.

  In step 103, the electrode system 120a is inserted into the narrow tube portion 130A. The tungsten electrode 123 is disposed in the light emitting unit 130C. At this time, the stopper 121a comes into contact with the tip of the narrow tube portion 130A. Accordingly, the insertion length of the electrode system 120a, that is, the length of the electrode system 120a inserted into the discharge vessel 130 is defined.

  In step 104, the discharge vessel 130 is attached to a sealing device (not shown). As shown in FIG. 3, the discharge vessel 130 is supported such that the central axis of the discharge vessel 130 is vertical and the narrow tube portion 130A to be sealed is on the upper side. The stopper 121a supports the entire weight of the electrode system 120a, the gas absorbing member 131, and the frit molded body 132.

  Note that step 102, step 103, and step 104 are not necessarily executed in this order. For example, step 103 may be executed, then step 102 may be executed, and first, the discharge vessel 130 may be attached to a sealing device (not shown).

  In step 105, a heater (not shown) disposed around the narrow tube portion 130A is operated. The frit molded body 132 is locally heated and melted by the heater. The sealing temperature is usually 1500 to 1700 ° C., but the frit is set to 1600 ° C. at which the frit has sufficient fluidity in order to avoid a sealing failure or a lack of sealing at the seal portion. The melted frit descends through the gap between the gas absorbing member 131 and the lead wire 121 due to gravity and capillary action. At this time, the melted frit comes into contact with the gas absorbing member 131. The melted frit further passes through the stopper 121a and enters the narrow tube portion 130A.

  The melted frit enters the gap between the inner surface of the narrow tube portion 130A and the lead wire 121 due to gravity and capillary action, and further enters the gap between the inner surface of the narrow tube portion 130A and the conductive cermet rod 122b. The melted frit completely closes the gap between the narrow tube portion 130A and the lead wire 121 and the gap between the narrow tube portion 130A and the conductive cermet rod 122b. The melted frit may penetrate to a predetermined position in the gap between the inner surface of the narrow tube portion 130A and the halogen-resistant intermediate material 122a.

  In step 106, heating by the heater is stopped. The melted frit is solidified to form a sealing material.

  Here, the function of the gas absorbing member 131 will be described. When the frit molded body 132 is melted, unnecessary gas such as hydrogen, carbon monoxide, carbon dioxide is released. These gases are known to be absorbed by metallic niobium and embrittle metallic niobium. That is, the metal niobium lead wire 121 becomes brittle when it absorbs these gases. According to the present embodiment, these gases are absorbed by the gas absorbing member 131. More specifically, at least the amount of gas absorbed and removed by the gas absorbing member 131 is sufficiently larger than the amount of gas absorbed by the metallic niobium lead wire 121. This will be described later. As described above, the molten frit comes into contact with the gas absorbing member 131 when descending through the gap between the gas absorbing member 131 and the lead wire 121. At this time, the gas generated by melting the frit molded body 132 is absorbed by the gas absorbing member 131. Therefore, according to the present embodiment, the amount of absorption by the metal niobium lead wire 121 among the gas generated by melting the frit molded body 132 is remarkably reduced, so that embrittlement of the lead wire 121 is avoided.

  Next, the material of the gas absorbing member 131 will be described. According to the present embodiment, the gas absorbing member 131 may be made of any material that can absorb the gas generated by melting the frit molded body 132. However, the gas absorbing member is preferably made of niobium metal. The cause of the embrittlement of the lead wire is that the gas generated by melting the frit molded body is absorbed by the lead wire made of niobium. Therefore, it is efficient to absorb and remove such gas by a gas absorbing member made of niobium made of the same material. Furthermore, even if the type of gas generated by melting the frit molded body cannot be specified, it can be removed.

  The gas absorbing member 131 may be made of another metal having a gas absorbing action equivalent to metal niobium, for example, tantalum. Niobium and tantalum belong to Group 5 elements called semimetals and have similar chemical properties.

  Next, the shape of the gas absorbing member 131 will be described. In the present embodiment, the gas absorbing member 131 has a large contact area with the melted frit and is configured to surround the lead wire 121 along the circumferential direction. Furthermore, it is preferable that the gas absorbing member 131 can be easily mounted around the lead wire 121 and can be easily manufactured. In the present embodiment, the gas absorbing member 131 is preferably formed in a coil shape, but may be configured by a cylindrical member. For example, you may form many groove | channels, a hole, and bending-shaped unevenness | corrugation in a cylindrical member. Thereby, the surface area of the gas absorbing member 131 is increased, and the contact area with the melted frit is increased.

  In order to increase the surface area of the gas absorbing member 131, it is conceivable to increase the inner diameter or axial dimension (height) of the coil or cylindrical member. However, when the inner diameter or axial dimension (height) of the gas absorbing member 131 is increased, the amount of the sealing material that fills the gap between the gas absorbing member 131 and the lead wire 121 increases, and is generated by melting of the frit molded body. Gas to increase. Therefore, even if the gas absorption amount is increased by increasing the surface area of the gas absorbing member 131, the amount of gas that is not absorbed by the gas absorbing member 131 will increase if the amount of gas that generates the melt frit increases further.

  Further, when the inner diameter of the gas absorbing member 131 is increased, the gap between the gas absorbing member 131 and the lead wire 121 is increased, and the gas generated from the molten frit that has entered the gap is lead before being absorbed by the gas absorbing member 131. Since it becomes easy to be absorbed by the wire 121, it is not preferable. Therefore, it is not a good idea to make the inner diameter and axial dimension (height) of the gas absorbing member 131 larger than a predetermined value.

  As described above, in the present embodiment, the amount of gas absorbed and removed by the gas absorbing member 131 rather than the amount of gas absorbed by the lead wire 121 out of the gas generated by melting the frit molded body. Is big enough. This will be described. In the present embodiment, since the gas absorbing member 131 is configured to surround the lead wire 121, the gas absorbing member 131 has a larger contact area with the molten frit than the lead wire 121. For example, when the gas absorbing member 131 is constituted by a coil, the contact area between the molten frit and the gas collecting member 131 is several times or more than the contact area between the molten frit and the lead wire 121.

  Further, in the sealing device (not shown), the heater is disposed so as to surround the gas absorbing member 131. Therefore, the distance between the gas absorbing member 131 and the heater is smaller than the distance between the lead wire 121 and the heater. Further, the radiant heat from the heater directly reaches the gas absorbing member 131, but does not reach the lead wire 121 directly because it is behind the gas absorbing member 131 and is blocked by the gas absorbing member 131. Therefore, the gas absorbing member 131 becomes hotter than the lead wire 121 during heating by the heater. The reaction rate between niobium metal and gas is higher as the temperature is higher. Also from this point, it can be said that most of the gas generated by melting the frit molded body is absorbed by the gas absorbing member.

  The shape, function, and material of the stopper 121a will be described. The stopper 121a may be formed of two bars or wires as shown in FIG. 2B. The wire diameter of the stopper 121a may be approximately the same as the wire diameter of the coil constituting the gas absorbing member 131, but may be larger or smaller.

  As described above, the stopper 121a defines the insertion length of the electrode system 120a, that is, the position of the electrode in the light emitting unit 130C of the discharge vessel 130. Further, the stopper 121a holds the electrode system 120a, the gas absorbing member 131, and the frit molded body 132 at the tip of the thin tube portion 130A when the discharge vessel 130 is held vertically by the sealing device.

  By providing the stopper 121a, a gap corresponding to the dimension (wire diameter) of the stopper 121a is formed between the gas absorbing member 131 and the tip of the thin tube portion 130A. Therefore, even if part of the molten frit flows downward through the outside of the gas absorbing member 131, the molten frit enters the gap between the narrow tube portion 130A and the electrode system 120a through this gap, and further covers the opening of the narrow tube portion 130A. Therefore, the seal at the tip of the narrow tube portion 130A can be ensured.

  According to the present embodiment, the gas absorbing member 131 may be formed of the same material as the gas absorbing member 131, and may be made of, for example, metallic niobium or metallic tantalum. However, in the present embodiment, the gas generated from the melt frit is absorbed by the gas absorbing member 131 and then reaches the stopper 121a. Therefore, it is not necessary to provide the stopper 121a with a gas absorbing function.

  FIG. 5 shows an example of the shape of the frit molded body 132 according to the present embodiment. In this embodiment, the frit molded body is formed in a ring shape. The inner diameter of the frit molded body 132 is D1, the outer diameter is D2, the thickness is t, and the weight is G. The outer diameter of the lead wire 121 is D0. The inner diameter D1 of the frit molded body 132 is larger than the outer diameter D0 of the lead wire 121. For example, D1 = 1.5 mm, D2 = 3.5 mm, or 4.3 mm, t = 0.9 mm, 1.4 mm, or 2.1 mm, and G = 23 to 85 mg.

The frit molded body 132 is formed by mixing a raw material with a binder and a dispersant, adding pure water to form a slurry, and granulating, pressure molding, and firing. When using a Dy ₂ O ₃ —Al ₂ O ₃ —SiO ₂ -based sealing material, dysprosium oxide (disprusia) Dy ₂ O ₃ , aluminum oxide (alumina) Al ₂ O ₃ , and silicon oxide are used as raw materials. (Silica) SiO ₂ is used. When the frit molded body 132 is heated and melted, carbon contained in the binder and the dispersant is oxidized to generate carbon monoxide, carbon dioxide, and the like. These gases embrittle metal niobium as described above.

  With reference to FIG. 6A, FIG. 6B, and FIG. 6C, the example of the shape of the gas absorption member 131 made as an experiment by the inventor of this application is demonstrated. In the example shown in FIG. 6A, the gas absorbing member 131 has a coil shape. The length of the coil in the axial direction is h, the inner diameter is d1, the outer diameter is d2, and the coil wire diameter is d0. d0 = 0.3 to 0.5 mm. The inner diameter d1 of the coil is 0.1 to 0.2 mm larger than the outer diameter D0 of the lead wire 121. When the outer diameter D0 of the lead wire 121 is D0 = 0.8 to 0.9 mm, d1 = 2.1 to 0.9 mm. The number of turns of the coil may be 3-5.

  In the example shown in FIG. 6B, the gas absorbing member 131 has a cylindrical shape. The length of the cylinder in the axial direction is h, the inner diameter is d1, the outer diameter is d2, and the thickness is t1. The inner diameter d1 may be equal to the inner diameter d1 of the coil shown in FIG. 6A. The thickness t1 is 0.1 mm or more.

  In the example shown in FIG. 6C, the gas absorbing member 131 is in the form of one or a plurality of thin plates. The thin plate-like member is disposed so as to sandwich the lead wire 121 and in a direction orthogonal to the axis of the lead wire. The dimension of the plate member in the longitudinal direction is h1, the dimension in the width direction is h2, and the thickness is t1.

  A test conducted by the inventors of the present application will be described with reference to FIGS. 7A and 7B. The inventor of the present application attaches the gas absorbing member 131 shown in FIGS. 6A, 6B, and 6C to the lead wire 121 of the narrow tube portion 130A of the discharge vessel 130, and seals the narrow tube portion 130A with a seal device (not shown). Formed. The discharge vessel 130 was taken out from the sealing device, and a lead rod bending test was performed.

  With reference to FIG. 7A, the method of the lead rod bending test performed by the inventors of the present application will be described. The narrow tube portion 130A of the discharge vessel 130 was fixed by a clamp device (not shown). The lead wire 121 protruding from the thin tube portion 130A was bent substantially vertically to the left and right. The number of bendings when the lead wire 121 was damaged was recorded. The counting method was “once” at the time of first folding, and “twice” at the time of returning straight.

  FIG. 7B shows the results of a lead bar bending test. The vertical axis represents the number of bendings when the lead wire 121 is broken. In the figure, the mean value μ of the number of bendings when the lead wire 121 is broken is represented by a black square point, and μ ± 3σ (σ is a standard deviation) representing the variation of the upper and lower lines extending from the black square point. Represented by the end. In the conventional example, when the gas absorbing member 131 is not used, when the coil-shaped gas absorbing member 131 shown in FIG. 6A is used in Example 1, the cylindrical gas-absorbing member 131 shown in FIG. 6B is used in Example 2. When used, the comparative example is the result when the thin plate-shaped gas absorbing member 131 of FIG. 6C is used.

  As shown in the drawing, in the conventional example, the lead wire 121 was damaged when the number of bendings was one. In the case of the comparative example, the average value of the number of bendings when the lead wire 121 was damaged was 3 times or less. That is, the lead wire 121 was damaged when the number of bendings was 1-3. In the case of Example 1, the average value of the number of bendings when the lead wire 121 was damaged was 7 times. That is, the lead wire 121 was damaged when the number of bendings was 5 to 10 times. In the case of Example 2, the average number of times of bending when the lead wire 121 was damaged was 5 times or more. That is, the lead wire 121 was damaged when the number of bendings was 4 to 7 times.

  In the lamp manufacturing process, the lead wire 121 may be bent by a welding operation or the like, but it is not repeatedly bent. Therefore, the inventor of the present application has passed the test when the number of folding exceeds 2 times and the sheet does not break. That is, an acceptable condition is that the average value of the number of bendings when broken is 3 times or more and the lower limit μ-3σ (σ is a standard deviation) of the variation is 2 times. Therefore, although the conventional example and the comparative example are unacceptable, both Examples 1 and 2 are acceptable. From the test conducted by the inventors of the present application, it can be seen that the use of the gas absorbing member 131 makes it difficult for the lead wire 121 to be damaged. Furthermore, although the shape of the gas absorption member 131 is arbitrary, it turns out that a coil shape is the most preferable. In the case of the coil-shaped gas absorbing member 131, it is easy to prepare a coil having an optimal size for the lead wire 121, and the contact area with the melted frit is relatively large.

  The ceramic metal halide lamp according to the present embodiment has been described above, but these are examples and do not limit the scope of the present invention. Additions, deletions, changes, improvements, and the like that can be easily made by those skilled in the art to the present embodiment are within the scope of the present invention. The technical scope of the present invention is defined by the appended claims.

  DESCRIPTION OF SYMBOLS 100 ... Ceramic metal halide lamp, 108 ... Translucent sleeve, 109 ... Frame, 110 ... Starter, 111 ... Translucent outer tube, 112 ... Base, 113 ... Getter, 114 ... Mount support plate, 115 ... Stem, 120a, 120b ... Electrode system, 121 ... Lead wire, 121a ... Stopper, 122 ... Current supply conductor, 122a ... Halogen-resistant intermediate material, 122b ... Conductive cermet rod, 122c ... Molybdenum rod, 122d ... Molybdenum coil, 123 ... Tungsten electrode, DESCRIPTION OF SYMBOLS 130 ... Discharge container, 130A, 130B ... Narrow tube part, 130C ... Light emission part, 131 ... Gas absorption member, 132 ... Frit molded object, 135 ... Sealing material

Claims (6)

A translucent outer tube, a discharge vessel having a light emitting portion and a thin tube portion, and an electrode system mounted on the thin tube portion of the discharge vessel, the electrode system comprising a tungsten electrode, a current supply conductor, and In ceramic metal halide lamps configured to have niobium lead wires,
The connecting portion between the current supply conductor and the lead wire is disposed inside the narrow tube portion, a part of the lead wire is disposed within the thin tube portion, and the remaining portion of the lead wire protrudes from the tip of the thin tube portion. A gas absorbing member that absorbs a gas generated when a seal portion is formed in the narrow tube portion is mounted around the vicinity of the narrow tube portion of the protruding portion ;
The lead wire is connected to a stopper for isolating the gas absorbing member and the tip of the narrow tube portion . The ceramic metal halide lamp according to claim 1,
The ceramic metal halide lamp, wherein the gas absorbing member is constituted by a coil made of niobium or tantalum. The ceramic metal halide lamp according to claim 1,
The current supply conductor includes a halogen-resistant intermediate material and a conductive cermet rod, the tungsten electrode is connected to the halogen-resistant intermediate material, and the lead wire is connected to the conductive cermet rod. Ceramic metal halide lamp. The ceramic metal halide lamp according to claim 3,
The length of the seal part in which the sealing material is formed in the narrow tube part is equal to or larger than the dimension from the tip of the narrow tube part to the inner end of the conductive cermet rod. lamp. A translucent outer tube, a discharge vessel having a light emitting portion and a thin tube portion, a tungsten electrode provided in the thin tube portion, a current supply conductor, and a lead wire made of niobium, and the lead wire includes the lead In a method of manufacturing a ceramic metal halide lamp, comprising: an electrode system to which two metal wire stoppers arranged so as to be orthogonal to the axis of the wire are connected;
A discharge vessel having a light emitting portion and a thin tube portion, and a lead wire made of niobium, to which two metal wire stoppers arranged so as to be orthogonal to the axis of the lead wire are connected. An electrode system comprising:
Attaching a gas absorbing member to the lead wire of the electrode system, and then attaching a frit molded body;
Inserting the electrode system into the capillary section;
Supporting the discharge vessel so that the central axis of the discharge vessel is vertical, abutting the stopper and the end surface of the narrow tube portion, and abutting the stopper and the gas absorbing member;
A melting step of heating and melting the frit molded body;
The molten frit flows into the narrow tube portion from between the stoppers while contacting the gas absorbing member, and when the gap between the inner surface of the thin tube portion and the electrode system is filled, the molten frit is solidified. Forming a sealing material;
A method of manufacturing a ceramic metal halide lamp having In the manufacturing method of the ceramic metal halide lamp of Claim 5 ,
The method for producing a ceramic metal halide lamp, wherein the gas absorbing member is constituted by a coil made of niobium or tantalum.

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