JP4446430B2 - Luminescent container for high pressure discharge lamp - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light-emitting container for a high-pressure discharge lamp and an end sealing member used therefor.
[0002]
[Prior art]
In the luminous container for a high-pressure discharge lamp described in Patent Document 1, a molded body of the tube main body and a molded body of the annular end sealing member are separately manufactured, and these two types of molded bodies are assembled to form an assembly. I am making it. And this assembly is baked and the container for metal halide enclosure is produced. At this time, the firing shrinkage ratio of both is designed so that the outer shape when the molded body of the end sealing member is baked alone is larger than the inner diameter when the molded body of the tube body is baked alone. deep. Then, since a crimping force is applied from the tube body to the end sealing member at the time of firing, the bonding between the two becomes good and the airtightness is maintained high.
[Patent Document 1]
Japanese Patent Application Laid-Open No. 10-125230
[Problems to be solved by the invention]
When the present inventor studied mass production of such a light-emitting container for a high-pressure discharge lamp, the following problems were found. This point will be described with reference to FIG. A light emitting container 11 for a high pressure discharge lamp shown in FIG. 10 includes a tube body 6 and an end sealing member 12. An inner side surface 6 a of the tube body 6 faces the discharge space 10. The end sealing member 12 includes a main body portion 12b and an annular portion 12a. The main body portion 12b of the end sealing member 12 is inserted into the end opening of the tube main body 6 and joined and integrated. A holding portion 9 a of the electrode member 9 is inserted and fixed in the electrode member insertion hole 12 d of the end sealing member 12. The electrode 9 b is accommodated in the discharge space 10. A gap between the inner side surface of the end sealing member 12 and the outer side surface of the electrode member 9 is sealed with a bonding material such as a glass frit 14.
[0004]
However, even when no cracks are seen in the container 11, cracks may be seen in the tube body 6 after the electrode member 9 is inserted into the end sealing member 12 and sealed with the bonding material 14. It was. In this case, it becomes a defective product, and there is a problem that the manufacturing yield decreases.
[0005]
An object of the present invention includes a tube main body and an end sealing member provided in the opening of the tube main body, and an assembly of the fired body of the tube main body and the fired body of the end sealing member. In the container manufactured by firing, the generation of cracks in the container after the electrode member is inserted into the end sealing member and sealed with the bonding material is suppressed.
[0006]
[Means for Solving the Problems]
The present invention includes a tube main body in which a discharge space is formed, and an end sealing member provided in an opening of the tube main body, and a fired body of the tube main body and a cover of the end sealing member. A luminous container for a high-pressure discharge lamp made of ceramics manufactured by firing an assembly with a fired body,
The end sealing member includes an outer end face, an inner end face facing the discharge space, and an electrode member insertion hole provided between the outer end face and the inner end face, and a recess is formed in the outer end face.
[0007]
Here, the said recessed part is following the said electrode member insertion hole, and is cyclically | annularly provided so that the said electrode member insertion hole may be surrounded. The bonding agent wets the outer end surface, the electrode member insertion hole, and the inner end surface.
[0008]
The present inventor investigated the cause of cracks in the container at the outer peripheral portion of the electrode member after inserting the electrode member into the end sealing member of the container and sealing it with a bonding material, leading to the next discovery. That is, as shown in FIGS. 10 and 11, cracks often appear mainly at the end portion A of the joint portion between the tube main body 6 and the end sealing member 12. Then, when the situation in the vicinity of A was examined, it was found that the bonding material 15 was wetted up to A. This means that the bonding material 14 overflows from the electrode member insertion hole 12 d of the end sealing member 12, wets the inner end surface 12 e, and further reaches the inner wall surface 6 a of the tube body 6. Such wetting of the inner wall surface 6a of the tube body 6 is considered to occur as follows. That is, if the maximum temperature at the time of bonding is too high or the holding time at the maximum temperature is too long, the bonding material 14 flows along the wall surface over a wide area as shown in FIG. 6 may reach the inner wall surface 6a. Moreover, when there are too many joining materials 14, a part may arrive at the inner wall surface 6a of the tube main body 6 as shown in FIG.
[0009]
Here, as described above, the end sealing member 12 and the tube body 6 are pressure-bonded due to the difference in the firing shrinkage rate. For this reason, stress remains along the joint portion between the two, and a fine gap also remains. If a part of the bonding material flows into this gap, it causes cracking in combination with residual stress. In particular, depending on the joining conditions, crystals having a thermal expansion coefficient lower than that of the ceramics constituting the tube body 6 may be generated in the bonding material 14. In this case, cracks are more likely to occur during the sealing process or during lighting.
[0010]
On the other hand, in the present invention, a concave portion is provided on the outer end surface of the end sealing member 12, and the concave portion is continuous with the electrode member insertion hole and is provided in an annular shape so as to surround the electrode member insertion hole. ing. This succeeded in suppressing cracks by absorbing a part of the bonding material in the melting step and making it difficult for the bonding material to reach the inner wall surface 6a of the tube body 6.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings as appropriate. FIG. 1 is a cross-sectional view showing a light-emitting container 8 for a high-pressure discharge lamp according to an embodiment of the present invention, and shows a state after the electrode member 9 is fixed. FIG. 2 shows the container 8 before the electrode member 9 is fixed. The container 8 of this example includes an end sealing member 7 and a tube body 6. An inner side surface 6 a of the tube body 6 faces the discharge space 10. The end sealing member 7 includes a main body portion 7b and an annular portion 7a. The main body portion 7b of the end sealing member 7 is inserted into the end opening of the tube main body 6 and joined and integrated. A holding portion 9 a of the electrode member 9 is inserted and fixed in the electrode member insertion hole 7 d of the end sealing member 7. The electrode 9 b is accommodated in the discharge space 10. A gap between the inner side surface of the end sealing member 7 and the outer side surface of the electrode member 9 is sealed with a bonding material, for example, a glass frit 14.
[0012]
In this example, the inner end face 7e of the end sealing member 7 is substantially flat, but a substantially annular recess 7c is formed on the outer end face 7f. And in a joining process, since a fluid joining material is absorbed in crevice 7c, it is hard to reach even inner wall surface 6a of tube body 6, and, thereby, the crack incidence rate of tube body 6 can be reduced.
[0013]
A luminous container 8A for a high-pressure discharge lamp outside the present invention shown in FIG. 3 includes an end sealing member 7A and a tube body 6. In the end sealing member 7A of this example, the outer end surface 7f is not provided with a recess and is substantially flat. An annular recess 7g is formed on the inner end surface 7e of the end sealing member 7A facing the discharge space 10 so as to surround the electrode member insertion hole 7d.
[0014]
A high pressure discharge lamp luminous vessel 8B shown in FIG. 4 includes an end sealing member 7B and a tube body 6. In the end sealing member 7B of this example, an annular recess 7g is formed on the inner end surface 7e facing the discharge space 10 so as to surround the electrode member insertion hole 7d. A substantially annular recess 7c is formed on the outer end surface 7f. As a result, in the joining process, the fluid joining material 14 is unlikely to reach the flat surface 7e, and therefore is difficult to reach the bottom wall surface 6a of the tube body 6.
[0015]
In the present invention , the recess is provided in an annular shape so as to surround the electrode member insertion hole 7d. This is effective in preventing the fluid bonding material from reaching the tube body 6 in the bonding step.
[0016]
In this invention , the recessed part is provided continuously with respect to the electrode member insertion hole.
[0017]
The ceramic constituting the container is not particularly limited, but a ceramic having corrosion resistance against a halogen-based corrosive gas is preferable. Particularly preferred are alumina, yttria, yttrium-aluminum garnet, and aluminum nitride.
[0018]
The material and form of the electrode member are not particularly limited. The material of the electrode member is preferably a refractory metal or conductive ceramic. As the refractory metal, one or more metals selected from the group consisting of molybdenum, tungsten, rhenium, hafnium, niobium and tantalum, or alloys containing these metals are preferable.
[0019]
The depth of the recess is not particularly limited. However, from the viewpoint of absorbing the fluid bonding material in the bonding process and suppressing the arrival at the tube body 6, the depth of the recess is preferably 0.2 mm or more, and 0.4 mm or more. Is more preferable. There is no particular upper limit on the depth of the recess. From the viewpoint of productivity during processing, the depth of the recess is preferably 0.3 mm or less.
[0020]
Type of the bonding material is not particularly limited, so-called frit glass is _{preferred, Al 2 O 3 -CaO-Y} 2 O 3 glass -SrO based composition system is particularly preferred.
[0021]
When a frit glass having a composition system of Al ₂ O ₃ —CaO—Y ₂ O ₃ —SrO is used, 12CaO · 7Al ₂ O ₃ crystals may be formed after melting depending on the joining conditions. For example, the thermal expansion coefficient of an alumina tube is 6.8 × 10 ⁻⁶ / ° C., and the thermal expansion coefficient of 12CaO · 7Al ₂ O ₃ is 5.98 × 10 ⁻⁶ / ° C., resulting in a considerable difference in thermal expansion. .
[0022]
Next, a preferred manufacturing process will be described. As shown in FIG. 5, the upper mold 1 and the lower mold 2 are prepared, and the powder 3 is accommodated in the lower mold 2. A protrusion 1 a is provided on the mold surface of the upper mold 1. As shown in FIG. 6, the upper die 1 and the lower die 2 are fitted together and assembled. The shape of the protrusion 1a is, for example, a shape capable of forming the recess 7c shown in FIG. The pressure at this time is determined by the type of powder. Next, the upper mold 1 and the lower mold 2 are released, and the molded body 4 is released. The molded body 4 includes an annular portion 4a, a main body portion 4b, a through hole 4d, and a recess 4c.
[0023]
Next, as shown in FIG. 8, the main body portion 4 b of the molded body 4 is inserted into the end portion of the opening 5 a of the molded body 5 of the tube body 6 to obtain the state shown in FIG. 9, thereby obtaining an assembly. The assembly 20 is fired to obtain, for example, the container shown in FIG.
[0024]
In this example, the molded bodies 4 and 5 were assembled to obtain the assembled body 20, and the assembled body 20 was fired. However, in this invention, the to-be-fired body of an edge part sealing member and the to-be-fired body of a tube main body may each be a calcined body other than a molded object, and may be a degreased body.
[0025]
In the firing step, the inner diameter when the molded body of the tube body is baked alone is made smaller than the outer diameter when the molded body of the end sealing member is baked alone. As a result, a pressing force is applied from the tube body to the end sealing member at the time of firing, both are strongly pressed and the airtightness is improved. From this viewpoint, the ratio (RO / RI) of the outer diameter RO when the molded body of the end sealing member is baked alone to the inner diameter RI when the molded body of the tube body is baked alone is In consideration of cracks and the like, it is preferably 1.005 or more, more preferably 1.010 or more. Further, RO is preferably 1.100 or less of RI, more preferably 1.080 or less, and further 1.060 or less, the effect is more remarkable.
[0026]
【Example】
Example 1
The container 8 shown in FIG. 1 was produced according to the procedure described with reference to FIGS. Specifically, to high-purity alumina powder having a purity of 99.9% or more, 750 ppm magnesium oxide, 2% by weight of polyvinyl alcohol, 0.5% by weight of polyethylene glycol and 50 parts by weight of water are added and pulverized by a ball mill for 1 hour. Mixed. The mixture was dried and granulated with a spray dryer at around 200 ° C. to obtain a granulated powder having an average particle size of about 70 μm and a static bulk density of 0.7 g / cm ³ .
[0027]
This granulated powder was press-molded under a pressure of 2000 kg / cm ² to obtain molded bodies 4 and 5 shown in FIG. At this time, the ratio (RO / RI) of the outer diameter RO when the molded body 4 of the end sealing member 7 is baked alone to the inner diameter RI when the molded body 5 of the tube body 6 is baked alone is 1. Both dimensions were adjusted to be .040.
[0028]
Next, the molded body 4 for the end sealing member was calcined at 1200 ° C. to shrink its dimensions. The calcined body was inserted into the end of the molded body 5 as shown in FIG. The assembled body was calcined at 1200 ° C., the molded body 5 for the tube body was shrunk, and a crimping force was applied from the molded body 5 to the calcined body for the end sealing member. Next, the assembly was fired at 1800 ° C., and the end sealing member and the tube main body were firmly joined.
[0029]
The outer diameter of the end sealing member 7 is 10.0 mm, the diameter of the recess 7 c is 7.0 mm, and the depth is 0.3 mm. When the inner diameter of the tube main body 6 thus obtained was measured at each portion, the inner diameter spread in the vicinity of the joint portion A with the end sealing member. The difference between the maximum value and the minimum value of the inner diameter was 0.2 mm.
[0030]
Next, an electrode member 9 made of Nb (hereinafter, all made of Nb) was inserted into the electrode member insertion hole 7d and joined with a joining material. As the bonding material, Al—Ca—Y—Sr based frit glass was used. The composition was Al ₂ O ₃ : 45% by weight, CaO: 40%, Y ₂ O ₃ : 5%, and SrO: 10%. The melting point of glass is 1370 ° C. ± 10 ° C. Bonding was performed under conditions of a maximum temperature of 1440 ° C. and a holding time of 5 minutes at the maximum temperature. The obtained bonded body was observed for cracks. Twelve samples were prepared, but no cracks were observed.
[003 1 ]
(Comparative Example 1)
A container 11 shown in FIGS. 10 and 11 was produced according to the procedure described with reference to FIGS. The manufacturing procedure is the same as in Examples 1 and 2, but the concave portion is not formed in the end sealing member.
[003 2 ]
After joining, the outer diameter of the end sealing member 11 is 10 mm. When the inner diameter of the tube main body 6 thus obtained was measured at each portion, the inner diameter spread in the vicinity of the joint portion A with the end sealing member. The difference between the maximum value and the minimum value of the inner diameter was 0.2 mm.
[003 3 ]
Next, the electrode member 9 made of molybdenum was inserted into the electrode member insertion hole 7d and joined with a joining material. As the bonding material, an Al—Ca—Y—Sr-based frit glass was used. The composition was Al ₂ O ₃ : 45% by weight, CaO: 40%, Y ₂ O ₃ : 5%, and SrO: 10%. The melting point of glass is 1370 ° C. ± 10 ° C. Bonding was performed under conditions of a maximum temperature of 1440 ° C. and a holding time of 5 minutes at the maximum temperature. The obtained bonded body was observed for cracks. Twelve samples were produced, but 10 were observed for cracks.
[003 4 ]
【The invention's effect】
As described above, according to the present invention, the tube main body and the end sealing member that seals the end thereof are provided, and the fired body of the tube main body and the fired body of the end sealing member In the container manufactured by firing the assembly, the generation of cracks in the container after the electrode member is inserted into the end sealing member and sealed with the bonding material can be suppressed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a state in which an electrode member 9 is fixedly joined to a container 8 according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing a container 8 according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view schematically showing a state in which an electrode member 9 is fixedly joined to a container 8A according to a reference embodiment outside the present invention.
FIG. 4 is a cross-sectional view schematically showing a state where an electrode member 9 is fixedly joined to a container 8B according to still another embodiment of the present invention.
FIG. 5 is a cross-sectional view schematically showing an upper mold 1 and a lower mold 2 used for molding a fired body of an end sealing member.
FIG. 6 is a cross-sectional view showing a state in which an upper die 1 and a lower die 2 are combined.
FIG. 7 is a cross-sectional view showing a molded body 4 of the end sealing member after release.
FIG. 8 is a cross-sectional view schematically showing a molded body 4 of an end sealing member and a molded body 5 of a tube main body.
FIG. 9 is a cross-sectional view schematically showing a state in which the molded body 4 of the end sealing member is inserted into the end opening of the molded body 5 of the tube main body.
FIG. 10 is a cross-sectional view schematically showing a state in which an electrode member 9 is bonded to the container 11 of the reference example with bonding materials 14 and 15;
FIG. 11 is a cross-sectional view schematically showing a state in which an electrode member 9 is bonded to the container 11 of the reference example with bonding materials 14 and 15;
[Explanation of symbols]
6 tube main body 6a inner wall surface 7, 7A, 7B end sealing member 7a annular portion 7b main body portion 7c, 7g recess 7d electrode member insertion hole 7e inner end surface 7f outer end surface 8, 8A, 8B container 9 electrode member 10 Discharge space 14 Bonding material 20 Assembly 15 Excess bonding material flowing on the inner end face of the end sealing member A Crack-prone portion

Claims (1)

A tube main body in which a discharge space is formed, and an end sealing member that seals an end of the tube main body, and a fired body of the tube main body and a fired body of the end sealing member, A ceramic container for a high-pressure discharge lamp manufactured by firing an assembly of
Said end sealing member, the outer end face, the inner end surface and the outer end surface facing the discharge space and comprising an electrode member insertion hole is provided between the inner end surface, the outer end face bonding agent, wherein The electrode member insertion hole and the inner end surface are wetted , a recess is formed in the outer end surface, the recess is continuous with the electrode member insertion hole, and is annular so as to surround the electrode member insertion hole A light-emitting container for a high-pressure discharge lamp, characterized by being provided in

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