JP3631599B2 - High pressure discharge lamp - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a high-pressure discharge lamp using a ceramic discharge tube.
[0002]
[Prior art]
In such a high-pressure discharge lamp, a closing material (usually called a ceramic plug) is inserted inside both ends of the ceramic discharge tube, each end is closed, and a through hole is formed in each closing material. The metal current conductor to which a predetermined electrode system is fixed is inserted into the through hole. An ionized luminescent material is sealed in the interior space of the ceramic discharge tube. As such a high-pressure discharge lamp, a high-pressure sodium light-emitting lamp and a metal halide lamp are known, and in particular, a metal halide lamp has a good color rendering property. By using ceramic as the material of the discharge tube, it can be used at high temperatures.
[0003]
In such a discharge lamp, it is necessary to hermetically seal between the end of the ceramic discharge tube and the electrode device holding material. The main body of the ceramic discharge tube has a tubular or barrel shape with both ends narrowed, or a straight tubular shape. The ceramic discharge tube is made of, for example, an alumina sintered body. As a method for sealing the end of the ceramic discharge tube, for example, Japanese Patent Laid-Open No. 6-318435 discloses the following structure. A plugging material is inserted and held inside the end of the ceramic discharge tube. A through hole is formed so as to extend in the axial direction of the blocking material, and an elongated electrode device holding material is inserted and fixed in the through hole. Here, the plugging material is formed by a cermet containing both alumina and a constituent metal of the electrode device holding material at a certain ratio, and the coefficient of thermal expansion of the plugging material is the coefficient of thermal expansion of the electrode device holding material and the ceramic discharge. It is located between the coefficient of thermal expansion of the tube.
[0004]
When this sealing structure is formed, when the ceramic discharge tube is fired in a state where the calcined body of the plugging material is not inserted into the calcined body of the ceramic discharge tube, the inner diameter of the end portion is outside of the plugging material. Designed to be smaller than the diameter. Therefore, the closing material is firmly clamped and held in the end portion of the ceramic discharge tube. The same applies to the closing material and the electrode device holding material.
[0005]
[Problems to be solved by the invention]
However, as a result of further investigation on such a sealing structure, the present inventor has found that there are the following problems. In other words, in this sealing structure, the pressure between the plugging material and the electrode device holding material is sealed between the two, but since the light-on / off cycle is repeated many times, the thermal expansion of both In view of the difference in coefficients, it is necessary to further improve the reliability of the sealing portion. In particular, since metal halide has high corrosivity, it is necessary to develop a seal structure having high corrosion resistance and reliability.
[0006]
An object of the present invention is to provide a novel seal structure having high corrosion resistance and reliability against metal halide or the like without substantially applying thermal stress between the plugging material and the ceramic discharge tube.
[0007]
[Means for Solving the Problems]
The high-pressure discharge lamp according to the first aspect of the present invention includes a ceramic discharge tube in which an internal space is filled with an ionized luminescent material and a starting gas, and a blockage in which at least a part is fixed inside an opening of the ceramic discharge tube. A high-pressure discharge lamp comprising a blocking member provided with a through hole, an electrode device provided in an internal space, and a conductive member attached to the blocking member. The conductive member is airtightly bonded to the end opposite to the space via the metallized layer. In addition, the conductive member is a hollow member It is characterized by that.
[0008]
The present inventor has conceived that the material of the closing material fixed to the end of the ceramic discharge tube and the material of the ceramic discharge tube are the same, and the closing material and the conductive member are hermetically bonded by the metallization layer. As a result of experiments, it was found that the blocking material and the conductive member maintained extremely high airtightness.
[0009]
In addition, the conductive member is attached to the end of the closing material opposite to the internal space via the metallization layer, and the end of the closing material is hermetically sealed. It has been found that even if the cycle is repeated many times, it has high reliability.
[0010]
The second aspect of the present invention is a ceramic discharge tube in which an internal space is filled with an ionized luminescent material and a starting gas, an electrode device provided in the internal space, and a conductive member attached to the ceramic discharge tube. The conductive member is hermetically bonded to the end portion of the opening portion of the ceramic discharge tube through the metallization layer. In addition, the conductive member is a hollow member It is characterized by that.
[0011]
That is, the present inventor has conceived that the conductive member is directly and airtightly bonded to the end portion of the ceramic discharge tube via the metallized layer without the blocking material. Accordingly, in addition to the above-described effects, the blocking material can be eliminated, so that the number of parts is reduced, and particularly the manufacturing process is greatly simplified. Therefore, the industrial advantage is extremely great.
[0012]
Moreover, the invention according to the second aspect is extremely effective for reducing the size of the high-pressure discharge lamp. That is, the dimension in the width direction of the high-pressure discharge lamp is limited by the dimension of the end. However, since the plugging material is inserted inside the end of the ceramic discharge tube, it is difficult to reduce the size in the width direction of the ceramic discharge tube to some extent. It was difficult to make it smaller. As a result, specifically, when the output was suppressed to a level of 25 W or less, the luminous efficiency of the space in the ceramic discharge tube was very low. According to the present invention, such downsizing is possible, which is epoch-making in that a high-pressure discharge lamp with a low output level of 25 W or less can be provided as a product.
[0013]
The effects of the present invention will be further described. There is usually a considerable amount of thermal expansion difference between the ceramic used as the material of the arc tube or the closing material and the conductive member, and this difference in thermal expansion is caused by the repeated cycling of the lamp on and off. It can be a cause. In this regard, according to the structure of the present invention, not only by pressure bonding as in the prior art, but also chemically bonded by the metallized layer, and since this metallized layer is not a completely rigid material, It has the effect of alleviating thermal strain generated at the interface. In addition, since the metallized layer has excellent corrosion resistance against halogen-based gas, the sealing effect and durability are remarkably high. In addition, it has been found that when the metallized layer is interposed at the end portion of the plugging material or the ceramic discharge tube and bonded while maintaining airtightness, the resistance to thermal cycling is significantly improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The conductive member may be an electrode device holding material to which the electrode device is directly attached, or may be a tubular member for inserting the electrode device holding material to which the electrode device is directly attached. There is no. As an example of the latter, the technique described in JP-A-6-318435 can be exemplified.
[0015]
As the material of the conductive member, various refractory metals and conductive ceramics can be used. From the viewpoint of conductivity, the refractory metal is more preferable. Such a refractory metal is preferably one or more metals selected from the group consisting of molybdenum, tungsten, rhenium, niobium, tantalum and alloys thereof.
[0016]
Among these, the thermal expansion coefficients of niobium and tantalum are almost balanced with the thermal expansion coefficient of ceramics constituting the ceramic discharge tube, particularly alumina ceramics, but these metals are known to be easily corroded by metal halides. Therefore, in order to extend the life of the conductive member, it is preferable that the conductive member is formed of a metal selected from the group consisting of molybdenum, tungsten, rhenium, and alloys thereof. However, metals having high corrosion resistance against these metal halides generally have a small coefficient of thermal expansion. For example, the thermal expansion coefficient of alumina ceramics is 8 × 10 ^-6 K ^-1 And the thermal expansion coefficient of molybdenum is 6 × 10 ^-6 K ^-1 The thermal expansion coefficient of tungsten and rhenium is 6 × 10 ^-6 K ^-1 It is as follows.
[0017]
When molybdenum is used as the material of the conductive member, La is further added to the molybdenum. ₂ O ₃ And CeO ₂ It is particularly preferable that at least one of the above is contained in a total of 0.1 wt% to 2.0 wt%.
[0018]
The metal constituting the metallized layer is preferably a metal selected from the group consisting of molybdenum, tungsten, rhenium, niobium, tantalum and alloys thereof. In particular, a metal selected from the group consisting of molybdenum, tungsten, rhenium and alloys thereof is particularly preferable in order to further improve the corrosion resistance of the metallized layer to halogen.
[0019]
This metallized layer can also contain a ceramic component. The ceramic component is preferably a ceramic that is corrosion resistant to ionized luminescent materials. ₂ O ₃ , SiO ₂ , Y ₂ O ₃ , Dy ₂ O ₃ , B ₂ O ₃ And MoO ₃ One or more ceramics selected from the group consisting of In particular, ceramics of the same kind as the material of the ceramic discharge tube are preferable, and alumina ceramics are particularly preferable.
[0020]
The content ratio of the metal component and the ceramic component in the metallized layer is preferably 30/70% by volume to 70/30% by volume. The thickness of the metallized layer is preferably 10 to 200 μm.
[0021]
Particularly preferably, the main component of the metal component constituting the metallized layer is selected from the group consisting of molybdenum, tungsten, rhenium and alloys thereof, and the main component of the ceramic component is composed of alumina, yttria, mullite and silica. It consists of 1 or more types of ceramics chosen from the group, and the ratio of both is 30 / 70-70 / 30 volume%. Furthermore, by adding 20% by volume or less of metal silicon to the metallizing material before firing, it reacts with oxygen in water vapor in the firing atmosphere, and the metal component in the metallization is joined with this oxygen to join. And improving the tightness of the metallization organization.
[0022]
In order to form the metallized layer in the present invention, a layered metallized material is interposed between the conductive member and the end of the firing body of the plugging material or the end of the fired body of the ceramic discharge tube. . The metallizing material refers to a material that forms a metallized layer after firing, and specifically includes a metal component and a ceramic component as described above.
[0023]
The layered metallizing material is preferably prepared by the following method.
(1) A metallized paste is applied and printed on the end of the firing body of the plugging material or the end of the fired body of the ceramic discharge tube, and / or the metallized paste is applied and printed on the outer surface of the conductive member. To do.
[0024]
In the metallized paste for constituting the metallized layer, it is preferable to add a binder having excellent thermal decomposability. Examples of such a binder include ethyl cellulose and an acrylic binder.
[0025]
(2) A cylindrical molded body made of a metallizing material is inserted and interposed between each of the above-mentioned fired bodies and the conductive member. Since this cylindrical molded body requires a structural strength that can withstand handling, it is preferably molded by a press molding method.
[0026]
When manufacturing this cylindrical molded object, a binder is added with respect to a metal component for an above described metallizing layer, and a ceramic component as needed. As the binder, a binder that is easily dissociated by heat and easily pressed is preferable, and polyvinyl alcohol (PVA) or an acrylic binder is preferable. A binder and a slight amount of solvent are added to the above components for the metallized layer, and granulated by a spray dryer or the like to produce granules. Or a granule can be formed by adding a binder and some solvent to the said component for metallizing layers, kneading | mixing, drying, and grind | pulverizing. 2-3 tons / cm of this granule ² A cylindrical molded body is obtained by press-molding at a pressure of 5 ° C. At the time of assembly, the tubular molded body is fitted to the conductive member, and the respective fired bodies are fitted to the outside of the cylindrical molded body. The firing conditions for the cylindrical molded body are the same as the firing conditions for the metallized paste.
[0027]
(3) A sheet-like molded body made of a material for metallization is interposed between each of the above-described fired bodies and the conductive member.
[0028]
In order to produce this sheet-like molded body, a binder such as an acrylic binder or ethyl cellulose is added to the metal component for the metallized layer and, if necessary, a ceramic component, and butyl carbitol acetate (BCA) or the like. A sheet-like molded body is obtained by, for example, a doctor blade method.
[0029]
As the material of the plugging material, the same material as the ceramic discharge tube is used. As a result, residual stress in the central axis direction of the ceramic discharge tube hardly occurs between the ceramic discharge tube and the plugging material. Here, the same kind of material means a material that is the same as the base ceramic, and the additive components may be different.
[0030]
When the conductive member is made of a metal, it is preferable that the metal component in the metallized layer and the conductive member contain a common material, thereby further improving the bonding force between them.
[0031]
The sealing method as described above can be adopted at both ends of the ceramic discharge tube, but at one of these ends, it is necessary to inject an ionized luminescent material through the inside of the conductive member. The sex member needs to be tubular. At the other end, various shapes of conductive members such as rods and tubes can be employed.
[0032]
The shape of the ceramic discharge tube can generally be tubular, cylindrical, barrel-shaped, or the like. When the electrode device holding material is tubular and the ionized luminescent material is sealed inside the discharge tube through the electrode device holding material, the electrode device holding material is closed by laser welding or TIG welding after the sealing.
[0033]
In the case of a metal halide high-pressure discharge lamp, an inert gas such as argon and a metal halide are sealed in the internal space of the ceramic discharge tube, and mercury is sealed as necessary.
[0034]
In the present invention, the conductive member is joined to the end portion of the plugging material or the end portion of the ceramic discharge tube.
(1) The end of the conductive member is joined to the end face of the closing material or the end face of the ceramic discharge tube. In this case, the stress applied to the metallized layer by the thermal cycle is significantly reduced, and in this sense, the life of the high-pressure discharge lamp is further extended.
[0035]
(2) The end of the conductive member is inserted into the through hole of the plugging material or the through hole of the ceramic discharge tube, and the inner peripheral surface of the end of the plugging material or the end of the ceramic discharge tube The outer peripheral surface of the end portion of the conductive member is bonded to the surface. In this case, particularly when the internal pressure of the ceramic discharge tube is high, durability against this pressure can be imparted.
[0036]
(3) In (2), a concave portion is further provided on the inner peripheral surface of the end portion of the closing member, and the end portion of the conductive member is accommodated in the concave portion. And are hermetically bonded through a metallized layer. Similarly, a recess is provided on the inner peripheral surface of the end portion of the opening portion of the ceramic discharge tube, the end of the conductive member is accommodated in the recess, and the end of the conductive member and the ceramic discharge tube are accommodated in the recess. Are hermetically bonded through a metallized layer.
[0037]
By adopting this structure, even if the pressure in the internal space of the ceramic discharge tube is, for example, 10 atmospheres or more, the metallized layer includes a portion extending vertically and a portion extending horizontally in the longitudinal direction of the ceramic discharge tube. Therefore, the durability against the gas pressure is remarkably high, so that the reliability is high and the stress relieving action by the thermal cycle is also high.
[0038]
Hereinafter, more specific embodiments of the present invention will be described with reference to the drawings.
[0039]
FIG. 1A is an enlarged sectional view showing the periphery of the opening portion 1a of the ceramic discharge tube 1, and FIG. 1B is a portion of FIG. 1A showing the details of a preferred example of the joining portion. It is an enlarged view.
[0040]
The inner surface 1b of the opening 1a of the ceramic discharge tube 1 extends straight when viewed in the central axis direction of the ceramic discharge tube. A blocking material 4 is inserted inside the opening portion 1a. The discharge tube 1 and the plugging material 4 are made of the same kind of ceramics, preferably alumina ceramics, and the interface between the two has almost disappeared in the firing stage. 4 c is an outer surface of the closing material 4.
[0041]
On the end surface 4 b side of the inner peripheral surface 4 a of the closing material 4, a concave portion or a step portion 9 is provided. The end 7 a of the conductive member 7 is accommodated in the recess 9. In this example, the conductive member 7 has a tubular shape, and is provided with an opening for sealing after sealing the starting gas and the ionized luminescent material.
[0042]
Between the closing material 4 and the conductive member 7, a metallized layer 6 is interposed in the recess 9, both are joined by the metallized layer 6, and airtightness is maintained. 7b is the outer surface of the conductive member 7, and 7c is its inner surface. The inner space of the conductive member 7 communicates with the inner space 3 of the discharge tube 1 through the through hole of the closing member 4.
[0043]
The metallized layer 6 is particularly preferably composed of a laminate of two metallized layers 10 and 11 as shown in FIG. However, the metallized layer 11 on the conductive member 7 side has a relatively high metal ratio, and the metallized layer 10 on the closing material 4 side has a metal ratio lower than that of the metalized layer 11. The stress due to the difference in thermal expansion between the closing material 4 and the conductive member 7 can be further reduced. The metallized layer 6 is further divided into three or more layers, three or more metallized layers are sequentially arranged from the closing material 4 or the ceramic discharge tube side toward the conductive member side, and the ratio of the metal in each metallized layer is determined as follows: It can be increased stepwise from the discharge tube side to the conductive member side.
[0044]
In this example, a metallized layer 5 is further formed along the inner peripheral surface 4 a of the closing material 4, and the electrode device 2 is attached to the end of the metallized layer 5 on the inner space 3 side.
[0045]
The method for mounting the electrode device is not limited to the form shown in FIG. For example, the electrode device can be attached as shown in FIGS. However, the same reference numerals are given to the components shown in FIG. 1, and the description thereof will be omitted.
[0046]
First, as shown in FIG. 2A, the conductive member 7 is joined to the closing material 4. Here, the electrode device is not attached to the internal space. Next, the electrode device 2 is attached to the sealing member (preferably made of metal) 12, and the sealing member 12 and the electrode device 2 are inserted into the internal space 3 and the through hole of the closing material 4 as shown in FIG. Then, the sealing member 12 is joined to the inner peripheral surface 7c of the conductive member 7 by welding or the like to form the sealing portion 13 as shown in FIG. As a result, the ionized luminescent substance and the starting gas in the internal space 3 are sealed so as not to come into contact with the outside air, and power can be supplied to the electrode device 2 via the sealing member 12.
[0047]
FIG. 3 relates to a second embodiment of the present invention. The inner surface 1b of the opening 1a of the ceramic discharge tube 1 extends straight when viewed in the central axis direction of the ceramic discharge tube. A recess or step 19 is provided on the end 1d side of the inner peripheral surface 1b of the opening portion 1a. The end 7 a of the conductive member 7 is accommodated in the recess 19. Between the discharge tube 1 and the conductive member 7, a metallized layer 15 is interposed in the recess 19, and both are joined by the metallized layer 15 and airtightness is maintained. Reference numeral 14 denotes a metallized layer connected to the electrode device 2.
[0048]
4 and 5 illustrate still another embodiment of the present invention. In FIG. 4, the end of the conductive member 7 faces the end surface 4 b of the closing member 4 with a slight gap therebetween. A metallized layer 16 is interposed between the end face 4b and the end 7a of the conductive member 7, and both are joined by the metallized layer 16 and airtightness is maintained.
[0049]
In FIG. 5, the end of the conductive member 7 is opposed to the end surface 1 c of the discharge tube 1 with a slight gap. A metallized layer 16 is interposed between the end surface 1c and the end 7a of the conductive member 7, and both are joined by the metallized layer 16 and airtightness is maintained.
[0050]
The metallized layer 16 is constituted by, for example, a laminate of two metallized layers 16a and 16b. However, the metallized layer 16b on the conductive member 7 side has a relatively high metal ratio, and the metallized layer 16a on the closing material 4 or the discharge tube 1 side has a metal ratio lower than that of the metallized layer 16b. Thus, the stress caused by the difference in thermal expansion between the plug 4 or the discharge tube 1 and the conductive member 7 can be further relaxed.
[0051]
In each of the embodiments described above, it is more preferable to further provide a ceramic fired layer between the metallized layers 6, 15, 16 and the ceramic discharge tube or the plugging material. This aspect will be further described. FIG. 6A is a cross-sectional view schematically showing an enlarged structure of a joint portion between the discharge tube 1 or the blocking member 4 and the conductive member 7.
[0052]
The microstructure of this sectional view is further enlarged and schematically shown in FIG. C is a conductive member and has a substantially dense microstructure. B is a metallized layer. A is a discharge tube or a blocking material. In the process of forming this bonded structure, both are firmly bonded by diffusion of the metal from the metallizing material to the conductive member, but the discharge tube or the plugging material is already strongly pressed and the particles are Grows and there are few pores, and migration and diffusion of ceramic components hardly occur. Further, when the metal component diffuses from the metallizing material to the discharge tube or the plugging material, there is an adverse effect.
[0053]
For this reason, as shown in FIG. 7A, it is particularly preferable to further generate a ceramic fired layer 20 between the discharge tube 1 or the blocking material 4 and the metallized layers 6, 15, 16. This microstructure is enlarged and schematically shown in FIG.
[0054]
A metallized layer B is formed next to the conductive member C having a substantially fine microstructure. D is a ceramic fired layer, and the ceramic component is easily diffused between the fired layer and the metallized layer, and the ceramic material is the same between the fired layer and the ceramic discharge tube or plugging material. A strong bond is likely to be generated by the diffusion of components.
[0055]
As described above, the ceramic component in the layered ceramic firing material is easily diffused into the ceramic discharge tube or the plugging material, the joint strength between them is further improved and stabilized, and the metallized layers 6, 15, 16 It is possible to prevent the diffusion of metal components into the ceramic structure of the discharge tube or the plugging material.
[0056]
Here, in order to generate the ceramic fired layer between the plugging material or the ceramic discharge tube and the metallized layer, a layered ceramic fired material is interposed here. The ceramic firing material refers to a material that forms a ceramic after firing, and specifically includes the ceramic components described above. The layered ceramic firing material can be preferably formed by the following method.
[0057]
(1) Apply and print ceramic paste.
[0058]
(2) A cylindrical molded body made of a ceramic firing material is inserted and interposed between the firing body of the plugging material or the fired body of the ceramic discharge tube and the layered metallizing material. Since this cylindrical molded body requires a structural strength that can withstand handling, it is preferably molded by a press molding method.
[0059]
When manufacturing this cylindrical molded object, a binder is added with respect to a ceramic component. As the binder, a binder that is easily dissociated by heat and easily pressed is preferable, and polyvinyl alcohol (PVA) or an acrylic binder is preferable. A binder and some solvent are added to the ceramic component, and granulated by a spray dryer or the like to produce granules. Or a granule can be formed by adding a binder and some solvent to a ceramic component, kneading | mixing, drying, and grind | pulverizing. 2-3 tons / cm of this granule ² A cylindrical molded body is obtained by press-molding at a pressure of 5 ° C.
[0060]
(3) A sheet-like molded body made of a ceramic firing material is interposed between the fired body of the plugging material or the fired body of the ceramic discharge tube and the layered metallizing material.
[0061]
In order to produce this sheet-like molded article, a binder such as acrylic binder or ethyl cellulose is added to the ceramic component, and a solvent such as butyl carbitol acetate is used. For example, a sheet-like molded article is obtained by a doctor blade method. Get.
[0062]
Next, the most suitable process for manufacturing the high-pressure discharge lamp according to each aspect of the present invention will be described. In the first aspect of the present invention, first, a material powder (preferably alumina powder) of the plugging material is formed to obtain a ring-shaped plugging material. At this stage, the powder granulated with a spray dryer or the like is used for 2000 to 3000 kgf / cm. ² It is preferable to press-mold at a pressure of The obtained molded body is preferably degreased and calcined to obtain a calcined body.
[0063]
At this time, the degreasing treatment is preferably performed by heating at a temperature of 600 to 800 ° C., and the calcination treatment is preferably performed by heating at a temperature of 1200 to 1400 ° C. in a hydrogen reducing atmosphere. By this calcining treatment, a certain degree of strength is imparted to the molded body of the plugging material, paste leveling failure due to inhalation of the solvent when the metallizing material is brought into contact with the plugging material is prevented, and the handling property of the plugging material is improved. be able to. The recess can be formed by machining, for example.
[0064]
Next, for example, a metallized paste is applied to a predetermined portion of the occluding material to form a metallized paste layer. As the metallized paste, Mo: 60 vol. % And Al ₂ O ₃ , Mullite and metal silicon at least 40 vol. %, A metallized paste composed of a small amount of binder and a solvent. The calcined body is preferably dried at 90 to 120 ° C.
[0065]
Next, the conductive member is opposed to a predetermined portion of the calcined body. This calcined body is pre-fired at a temperature of 1200 to 1600 ° C. in a reducing atmosphere having a dew point of 20 to 50 ° C. (baking step).
[0066]
On the other hand, the main body of the ceramic discharge tube is formed, the formed body is degreased, and calcined to obtain a calcined body of the ceramic discharge tube. The pre-fired body of the plugging material is inserted into the end face of the obtained calcined body, set at a predetermined position, and subjected to main firing at a temperature of 1600 to 1900 ° C. in a reducing atmosphere having a dew point of 15 to 15 ° C. The high-pressure discharge lamp of the present invention is obtained.
[0067]
Note that the metallized paste can be printed on the conductive member without printing the metallized paste on the closing material. Further, a ceramic paste made of the same kind of material as the plugging material can be applied to the surface of the plugging material to form a ceramic paste layer, and a metallized paste can be applied thereon.
[0068]
The ceramic discharge tube shown in FIG. 4 was produced according to the manufacturing process described above. However, the ceramic discharge tube and the plugging material were formed of alumina porcelain, and a molybdenum pipe was used as the conductive member. Moreover, joining of the blocking material and the conductive member was carried out with a 50% by volume: 50% by volume metallized layer of molybdenum-alumina.
[0069]
The ceramic discharge tube was subjected to a thermal cycle test. Specifically, it was held at room temperature for 15 minutes, then the temperature was raised to 850 ° C., held at 850 ° C. for 5 minutes, and then the temperature was lowered to room temperature as one cycle, and 500 heat cycles were performed. . Thereafter, when the presence or absence of a leak was measured by a helium leak test, the leak amount was 10 ^{-1 0} It was less than atm · cc · sec. In addition, 850 degreeC is the temperature of the sealing part at the time of normal use.
[0070]
Moreover, the ceramic discharge tube shown in FIG. 1 was produced according to the manufacturing process described above. However, the ceramic discharge tube and the plugging material were formed of alumina porcelain, and a molybdenum pipe was used as the conductive member. Moreover, joining of the blocking material and the conductive member was carried out with a 50% by volume: 50% by volume metallized layer of molybdenum-alumina.
[0071]
The ceramic discharge tube was subjected to a thermal cycle test. Specifically, it was held at room temperature for 15 minutes, then the temperature was raised to 950 ° C., held at 950 ° C. for 5 minutes, and then the temperature was lowered to room temperature as one cycle, and 500 heat cycles were performed. . Thereafter, when the presence or absence of a leak was measured by a helium leak test, the leak amount was 10 ^{-1 0} It was less than atm · cc · sec. Note that 950 ° C. is an overload temperature. The durability against this means that even when the starting gas and the ionized luminescent material are press-fitted into the discharge tube at a higher pressure than usual, it can be safely maintained for a long period of time.
[0072]
In order to produce the ceramic discharge tube of the second aspect of the present invention, the main body of the ceramic discharge tube is formed, the formed body is degreased and calcined to obtain a calcined body of the ceramic discharge tube. As described above, the metallized paste is applied to a predetermined portion of the obtained calcined body. At this time, if necessary, before the metallized paste, a ceramic paste made of the same material as the calcined body is applied. The calcined body is dried in air at 90 to 120 ° C. A conductive member is disposed and fixed at a predetermined site, pre-baked at a temperature of 1200 to 1600 ° C. in a reducing atmosphere having a dew point of 20 to 50 ° C., and then 1700 in a reducing atmosphere having a dew point of 15 to 15 ° C. The main baking is performed at a temperature of ˜1900 ° C. The preliminary firing and the main firing may be performed independently, but can be performed continuously when an atmosphere furnace having both reducing atmospheres can be used.
[0073]
Alternatively, the calcined body is heated and degreased at 300 to 400 ° C. in air or in a nitrogen atmosphere, and assembled, and at a temperature of 1700 to 1900 ° C. in a reducing atmosphere having a dew point of 15 to 15 ° C. The main firing is performed.
[0074]
Further, in the above-described process, the metallized paste (and ceramic paste as necessary) is not applied to the main body of the ceramic paste layer, and the metallized paste (and ceramic as necessary) is applied to a predetermined portion of the surface of the conductive member. Paste) can also be applied.
[0075]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a novel seal structure having high corrosion resistance and reliability against metal halides and the like.
[Brief description of the drawings]
1A is a cross-sectional view showing a discharge tube end joint structure according to an embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing a preferred form of a metallized layer 6; FIG.
FIGS. 2A, 2B, and 2C illustrate a mode in which a sealing member 12 of an electrode device is bonded to a conductive member using a bonding structure as illustrated in FIG. FIG.
FIG. 3 is a cross-sectional view showing a discharge tube end joint structure according to another embodiment of the present invention, in which a conductive member is joined to a recess at the end of the discharge tube 1;
FIG. 4 is a cross-sectional view showing a discharge tube end joint structure according to still another embodiment of the present invention, in which a conductive member is joined to an end face 4b of a blocking material 4;
FIG. 5 is a cross-sectional view showing a discharge tube end joint structure according to still another embodiment of the present invention, in which a conductive member is joined to an end face 1c of the discharge tube 1;
FIGS. 6A and 6B are cross-sectional views schematically showing a microstructure of a joined portion of a discharge tube or a blocking material, a metallized layer, and a conductive member.
FIGS. 7A and 7B are cross-sectional views schematically showing a microstructure of a joined portion of a discharge tube or a plugging material, a ceramic fired layer, a metallized layer, and a conductive member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ceramic discharge tube 1a Opening part 2 Electrode apparatus 3 Internal space 4 Occlusion material 4a Inner peripheral surface of the occlusion material 4b End surface of the occlusion material 4c Outer surface of the occlusion material 4 5 Metallized layers in the through holes of the occlusion material 16 Metallized layer 7 Conductive member 7a End portion of conductive member 7b Outer side surface of conductive member 7c Inner side surface of conductive member 7 Recessed portion of closure member 4 10, 11, 16a, 16b Different metallization layers 19 Recesses in ceramic discharge tubes

Claims (8)

A ceramic discharge tube in which an internal space is filled with an ionized luminescent substance and a starting gas, and a blocking material in which at least a part is fixed inside an opening portion of the ceramic discharge tube, and is provided with a through hole A high-pressure discharge lamp comprising a material, an electrode device provided in the internal space, and a conductive member attached to the closure material, at an end of the closure material opposite to the internal space On the other hand, the conductive member is hermetically bonded via a metallized layer , and the conductive member is a hollow member . The high-pressure discharge lamp according to claim 1, wherein the metallized layer and the ceramic fired layer are formed in this order between the conductive member and the blocking material. A concave portion is provided on the inner peripheral surface of the end portion of the closing material, and the end portion of the conductive member is accommodated in the concave portion, and the end portion of the conductive member and the closing portion are accommodated in the concave portion. The high pressure discharge lamp according to claim 1 or 2, characterized in that a material is hermetically bonded via the metallized layer. A high-pressure discharge lamp comprising a ceramic discharge tube filled with an ionized luminescent substance and a starting gas in an internal space, an electrode device provided in the internal space, and a conductive member attached to the ceramic discharge tube. In addition, the conductive member is hermetically bonded to the end portion of the opening portion of the ceramic discharge tube via the metallization layer , and the conductive member is a hollow member, and the high pressure discharge Electric light. The high-pressure discharge lamp according to claim 4, wherein the metallized layer and the ceramic fired layer are formed in this order between the conductive member and the ceramic discharge tube. A concave portion is provided in the inner peripheral surface of the end portion of the opening portion of the ceramic discharge tube, and an end portion of the conductive member is accommodated in the concave portion, and the conductive member is accommodated in the concave portion. 6. The high-pressure discharge lamp according to claim 4, wherein an end portion and the ceramic discharge tube are hermetically joined via the metallized layer. The high-pressure discharge lamp according to claim 3, wherein the metallized layer is formed along an inner peripheral surface of the closing material. The high pressure discharge lamp according to claim 6, wherein the metallized layer is formed along an inner peripheral surface of an end portion of the opening portion of the ceramic discharge tube .

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