JP2011103250A - Double-tube type ultraviolet lamp - Google Patents

Abstract

A double tube type ultraviolet lamp having a simple sealing structure is provided.
An ultraviolet lamp (22), an outer tube (21) disposed on the outer side, and a metal cap (25) placed on an end of the outer tube (21) are provided. The lead wire 6 of the ultraviolet lamp 22 is inserted into an insertion hole provided in the metal cap 25. A space between the metal cap 25 and the outer tube 21 is preferably filled with a sealing material and hermetically sealed. For example, the lead wire 6 and the metal cap 25 have a structure in which the lead wire 6 and the metal cap 25 are joined in an airtight manner with a conductive material. Thereby, the outer tube can be sealed with the metal cap without being heated by the burner.
[Selection] Figure 1

Description

  The present invention relates to a low-pressure ultraviolet lamp, and more particularly to a low-pressure ultraviolet lamp for sterilization.

  The low-pressure ultraviolet lamp for sterilization is classified into a hot cathode type and a cold cathode type according to a discharge method. Both use mainly 185.0nm and 253.7nm resonant ultraviolet rays emitted by mercury vapor discharge, and there are two types of names, ozone lamps and sterilizing lamps, depending on the emitted wavelength range.

  The ozone lamp is an ultraviolet lamp that emits ultraviolet rays having both wavelengths of 185.0 nm (ozone rays) that generate ozone having a deodorizing and sterilizing effect and 253.7 nm (sterilizing rays) having a sterilizing effect. As the sealing material, synthetic quartz having a high transmittance of 200 nm or less is used.

  The sterilizing lamp is an ultraviolet lamp that cuts ozone rays (185.0 nm) and emits mainly sterilizing rays (253.7 nm). For the sealing material, TiO2 or the like is added, and quartz (ozone-less quartz) or ultraviolet transmissive glass (barium silica-based soft glass) that acts to cut ozone rays is used.

  When manufacturing synthetic quartz ozone lamps or ozoneless quartz germicidal lamps, the edge of the quartz glass is formed by a so-called foil sealing structure in which a metal foil such as Mo is arranged at the connection between the cold cathode shaft and the lead wire. The part is sealed. On the other hand, when manufacturing a sterilizing lamp made of ultraviolet transmissive glass, the ultraviolet transmissive glass tube is sealed by a so-called bead structure in which a sealing wire such as Kovar is sealed with glass beads.

  When using a low-pressure ultraviolet lamp for sterilization in a commercially available air sterilizer, etc., it is common to perform air sterilization by forcibly convection of air with a fan etc. after making the structure that ultraviolet rays do not leak outside for safety . However, if the low-pressure ultraviolet lamp for sterilization is installed inside an air sterilizer or the like with a single tube, the lamp body is cooled by air convection and the ultraviolet radiation efficiency is lowered. As a result, there arises a problem that the sterilizing effect is also lowered. Therefore, it is possible to produce a heat retaining effect by arranging an outer tube outside the low-pressure ultraviolet lamp for sterilization and sealing the space between the single tube (inner tube) and the outer tube while keeping the airtightness. Documents 1 and 2 disclose this. It is disclosed that the space between the single tube and the outer tube is a vacuum, an inert gas atmosphere, or an air atmosphere.

JP-A-1-136660 JP 2003-142029 A

  When the low-pressure ultraviolet lamp for sterilization has a double tube structure, there arises a problem that the sealing structure and the electrode structure are complicated.

  For example, when a double tube is sealed with a foil sealing structure, as shown in FIG. 11, the outer tube 12 is formed outside the foil sealing portion 5 of a single tube (quartz glass tube 1) in which the cold cathode 2 is arranged. Since it is necessary to seal further, it is necessary to arrange the metal foil 3 also in the sealing portion 13 of the outer tube 12. Therefore, the metal foil 3 is arranged in the foil sealing part 5 of the single tube 1 and the foil sealing part 13 of the outer tube 12 respectively. On the other hand, when the double tube is sealed with the bead sealing structure, the outer tube 14 is further bead-sealed outside the bead sealing portion 10 of the single tube (ultraviolet transmitting glass tube 7) as shown in FIG. In order to form the sealing portion 15, it is necessary to make the sealing wire 9 connected to the cold cathode 2 longer than in the case of a single tube alone. In any structure, the sealing structure and the electrode structure are complicated by the double tube structure.

  Also in the manufacturing process, the manufacturing process is complicated because it is necessary to heat and seal the ends of the outer tubes 12, 14 and the metal foil 3 and the sealing wire 9 with a burner or the like. .

  These problems occur not only in the cold cathode type but also in the case where a double tube structure is adopted in a low pressure ultraviolet lamp of a hot cathode.

  An object of the present invention is to provide a double tube type ultraviolet lamp having a simple sealing structure.

  In order to achieve the above object, according to the first aspect of the present invention, the following double tube type ultraviolet lamp is provided. That is, it is a double-tube ultraviolet lamp having an ultraviolet lamp, an outer tube disposed outside the ultraviolet lamp, and a metal cap placed on the end of the outer tube. The ultraviolet lamp includes a cold cathode and a lead wire connected to the cold cathode. The lead wire is inserted into an insertion hole provided in the metal cap, and is joined to the metal cap in an airtight manner by a conductive material. Accordingly, the outer tube can be sealed with the metal cap and the lead wire and the metal cap can be connected without heating and sealing the outer tube with a burner or the like, so that a simple sealing structure can be realized.

  Between the metal cap and the outer tube, for example, a sealing material can be filled and hermetically sealed.

  The metal cap has, for example, a conical shape around the insertion hole. Thereby, the lead wire of the cold cathode can be easily inserted into the insertion hole by covering the outer tube with the metal cap.

  According to the second aspect of the present invention, the following double tube type ultraviolet lamp is provided. That is, it is a double-tube ultraviolet lamp having an ultraviolet lamp, an outer tube disposed outside the ultraviolet lamp, and a metal cap placed on the end of the outer tube. The ultraviolet lamp has a hot cathode and two lead wires connected to the hot cathode. Two insertion holes are provided side by side in the metal cap, and a cylindrical terminal with one end sealed is inserted into each insertion hole. An insulating material is filled between the cylindrical terminal and the metal cap so as to keep airtight. The two lead wires of the ultraviolet lamp are inserted from the other ends of the two cylindrical terminals and are in electrical contact with the terminals, respectively. Thus, the two lead wires can be electrically connected independently to the cylindrical terminals of the metal cap, and airtightness can be maintained.

  For example, the cylindrical terminal can have a tapered shape in which the inner diameter gradually decreases as the inner diameter moves away from the ultraviolet lamp. Thereby, the two lead wires of the hot cathode can be easily inserted into the cylindrical terminal and can be brought into electrical contact with the cylindrical terminal.

Sectional drawing of the double-tube type cold cathode ultraviolet lamp of 1st Embodiment. Sectional drawing of the cold cathode ultraviolet lamp main body which can be used for 1st Embodiment. Sectional drawing of the cold cathode ultraviolet lamp main body which can be used for 1st Embodiment. The perspective view of the cup type metal cap used for the cold cathode ultraviolet lamp of 1st Embodiment. Sectional drawing of the double-tube type cold cathode ultraviolet lamp of 2nd Embodiment. The perspective view of the cup type metal cap used for the cold cathode ultraviolet lamp of 2nd Embodiment. Sectional drawing of the double tube type cold cathode ultraviolet lamp of 3rd Embodiment. The perspective view of the hermetic seal type | mold metal cap used for the cold cathode ultraviolet lamp of 3rd Embodiment. Sectional drawing of the double tube | pipe type cold cathode ultraviolet lamp of 4th Embodiment. The graph which shows the atmospheric temperature dependence of the ultraviolet radiation intensity | strength of the ultraviolet lamp of an Example and Comparative Examples 1 and 2. FIG. Sectional drawing of the conventional double tube type cold cathode ultraviolet lamp. Sectional drawing of the conventional double tube type cold cathode ultraviolet lamp.

  A double tube type low-pressure ultraviolet lamp according to an embodiment of the present invention will be described. In this invention, it is set as the structure which seals the edge part of an outer tube | pipe using a cup-shaped metal cap. Thereby, it is possible to achieve electrical conduction to the electrode of the inner tube while maintaining airtightness with a simple structure.

(First embodiment)
FIG. 1 shows a cross-sectional view of the double-tube type cold cathode ultraviolet lamp of the first embodiment. The double tube type cold cathode ultraviolet lamp shown in FIG. 1 includes a single tube cold cathode ultraviolet lamp main body 22 (inner tube), an outer tube 21 arranged on the outer side, and a cup for sealing the end of the outer tube 21. A mold metal cap 25 is provided.

  The single tube cold cathode ultraviolet lamp main body 22 uses a so-called sterilizing lamp that mainly emits light having a wavelength of 253.7 nm. The cold cathode ultraviolet lamp main body 22 may have any structure. For example, a germicidal lamp having the structure shown in FIG. 2 using an ozone-less quartz tube 1 that cuts ozone rays at 185.0 nm, or an ultraviolet-transmitting soft glass tube 7 that cuts ozone rays (for example, barium silica-based). 3 having a structure of FIG. 3 using soft glass can be used.

  Specifically, the sterilization lamp having the structure shown in FIG. 2 has a structure in which cold cathodes 2 are arranged at both ends of an ozoneless quartz tube 1. A metal foil 3 such as Mo is disposed at a connection portion between the shaft portion 4 and the lead wire 6 of the cold cathode 2, and an end portion of the quartz glass 1 is sealed by a so-called foil sealing structure 5. The sterilization lamp having the structure shown in FIG. 3 has a structure in which cold cathodes are disposed at both ends of the ultraviolet light transmissive soft glass tube 7, respectively. A sealing wire 9 such as Kovar connected to the cold cathode 2 is sealed with glass beads, and a UV transparent soft glass tube 7 is sealed with a so-called bead structure 10.

  The outer tube 21 may be made of a material that mainly transmits light having a wavelength of 253.7 nm. For example, a soft glass such as quartz, ozoneless quartz, or barium silica is used.

  As shown in the perspective view of FIG. 4, the cup-type metal cap 25 is composed of a cylindrical portion 25a and a bottom portion 25b that closes an opening on one side thereof. An insertion hole 18 for inserting the lead wire 24 of the cold cathode ultraviolet lamp main body 22 is provided in the center of the bottom portion 25b. The inner diameter of the cylindrical portion 25a is designed to be slightly larger than the outer shape of the outer tube 21.

  The material of the cup-type metal cap 25 is, for example, an iron-based alloy.

  The outer tube 21 is covered with a cup-shaped metal cap 25 at the end, and the end surface of the outer tube 21 is abutted against the bottom 25 b of the cup-shaped metal cap 25. In this state, the length of the lead wire 6 and the length of the outer tube 21 are designed so that the tip of the lead wire 6 of the inner cold cathode ultraviolet lamp body 22 is inserted into the insertion hole 18 of the cup-shaped metal cap 25. Has been. A gap between the tip of the lead 6 and the insertion hole 18 is filled with solder or the like, and an airtight sealing portion 27 is formed.

  A space 26 between the outer tube 21 and the cup-shaped metal cap 25 is filled with a material excellent in ultraviolet resistance, such as silicone resin or solder glass, and hermetically sealed. This filling material is more preferable when it is excellent in ozone resistance.

  With such a structure, the space between the inner cold cathode ultraviolet lamp main body 22 and the outer tube 21 is kept airtight, so that the inner cold cathode ultraviolet lamp main body 22 is cooled by air convection. Can be prevented. Therefore, the ultraviolet radiation efficiency can be maintained at a high efficiency. The space 28 between the inner cold cathode ultraviolet lamp main body 22 and the outer tube 21 is here an atmospheric atmosphere. Note that the space 28 can be evacuated to a predetermined degree of vacuum or can be filled with an inert gas.

  Further, since the cup-type metal cap 25 and the lead wire 6 are electrically connected, the cold cathode ultraviolet lamp main body 22 can be turned on by applying a voltage to the cup-type metal cap 25.

  By adopting the structure of the present embodiment, a cold cathode ultraviolet lamp having a general structure can be enclosed as it is as the main body 22 inside the outer tube 21, and the lead wire 6 and the outer tube 21 are soldered, etc. While having a simple sealing structure in which 25 and the outer tube 21 are sealed with a silicone resin or the like, a dual structure cold cathode ultraviolet lamp can be provided. The cold cathode ultraviolet lamp of the present embodiment can maintain the temperature of the cold cathode ultraviolet lamp main body 22 due to the heat-retaining effect of the double tube, and thus is less susceptible to the outside air temperature and can maintain the ultraviolet radiation efficiency. Further, unlike the conventional double tube structure UV lamp, it is not necessary to hermetically seal the outer tube with a burner or the like, so that the manufacturing process is not complicated.

(Second Embodiment)
FIG. 5 shows a cross-sectional view of the double tube type cold cathode ultraviolet lamp of the second embodiment. The double tube type cold cathode ultraviolet lamp of FIG. 5 is different in the shape of the cup type metal cap 29 from the cup type metal cap 25 of the first embodiment. Since other structures and manufacturing methods are the same as those of the first embodiment, description thereof is omitted.

  As shown in the perspective view of FIG. 6, the cup-shaped metal cap 29 according to the second embodiment includes a cylindrical portion 29a and a conical portion 29b connected so as to close the opening on one side. . The conical portion 29b is connected to the cylindrical portion 29b so as to protrude outward. An insertion hole 18 for inserting the lead wire 24b is provided at the tip of the conical portion 29b.

  In this way, by making the bottom of the cup-shaped metal cap 29 conical, the tip of the lead wire 6 is conical by covering the end of the outer tube 21 with the cup-shaped metal cap 29 as shown in FIG. It is guided by the inner wall of the portion 29b and inserted into the insertion hole 18 at the tip. Thereby, the lead wire 6 can be easily inserted into the insertion hole 18, and the productivity is improved. Thereafter, the tip of the lead wire 6 and the cup-shaped metal cap 29 are joined by soldering or the like to form the joint portion 27. In addition, the space 28 between the cup-shaped metal cap 29 and the outer tube is sealed with a material excellent in ultraviolet resistance as in the first embodiment.

  Note that the length of the lead wire 6 is designed to reach the insertion hole 18 of the cap 29.

(Third embodiment)
FIG. 7 shows a cross-sectional view of the double tube type ultraviolet lamp of the third embodiment. The ultraviolet lamp of FIG. 7 uses a hot cathode type ultraviolet lamp as the ultraviolet lamp body 32. Since the hot cathode ultraviolet lamp main body 32 has two lead wires 24 on one side, a hermetic seal type metal cap 31 is used.

  The sealing structure 23 at the end of the hot cathode ultraviolet lamp main body 32 may be any structure.

  As shown in FIG. 8, the hermetic seal type metal cap 31 includes a cylindrical portion and a bottom portion 31 b that closes one opening of the cylindrical portion 20. The bottom portion 31b is provided with two openings at intervals equivalent to the interval between the lead wires 24, and metal cylindrical terminals 33 are inserted into the two openings, respectively. As shown in FIG. 7, the cylindrical terminal 33 is sealed on the outer side of the outer tube 21 with a metal bottom 33 a. The tip of the cylindrical terminal 33 on the inner space side of the outer tube 21 is an opening 33b.

  An insulating member 31c such as glass is filled between the bottom 31b of the metal cap 31 and the cylindrical terminal 33, and the metal cap 31 has a sealing structure, and the cylindrical terminal 33 is attached to the metal cap 31. It is electrically insulated from it.

  By covering the end of the outer tube 21 with the metal cap 31, the two lead wires 24 are inserted into the opening 33b of the cylindrical terminal 33, and the leading end of the lead wire 24 contacts the bottom 33b of the cylindrical terminal 33. To do. Thereby, the lead wire 24 and the cylindrical terminal 33 are electrically connected.

  The gap between the cylindrical portion 31a of the metal cap 31 and the outer tube 21 is sealed as in the first embodiment. As a result, it is possible to manufacture a hot cathode ultraviolet lamp having a double tube structure that is airtight. The material of the outer tube 21 and the atmosphere of the gap between the main body 32 and the outer tube 21 are the same as in the first embodiment.

  By supplying power to the cylindrical terminal 33 from the outside, power is supplied to the lead wire 24, and a germicidal wire is radiated from the hot cathode ultraviolet lamp main body 32. Due to the double tube structure, the inner cold cathode ultraviolet lamp main body 22 can be prevented from being cooled by air convection, and the ultraviolet radiation efficiency can be maintained at a high efficiency.

(Fourth embodiment)
FIG. 9 shows a cross-sectional view of the double tube type hot cathode ultraviolet lamp of the fourth embodiment. In the hot cathode ultraviolet lamp of FIG. 9, the structure of the terminal 30 of the hermetic seal type metal cap 31 is tapered such that the inner diameter becomes smaller as it approaches the outer end. Since other structures are the same as those of the third embodiment, description thereof is omitted.

  Since the terminal 30 of the metal cap 31 is tapered, the lead wire 24 can be guided to the inner wall of the terminal 30 and inserted to the tip of the terminal 30 when it is put on the outer tube 21. As a result, the lead wire 24 can be easily inserted into the terminal 30, and there is an advantage that productivity is improved.

  In the said 1st-4th embodiment, although the germicidal lamp using an ozone-less quartz tube etc. which cuts an ozone line of 185.0nm was demonstrated, the double tube structure of each embodiment is not restricted to this, Ozone rays It can also be applied to ozone lamps that emit both 253.7nm germicidal lines. In this case, a quartz tube is used as the outer tube 21. In addition, by using an ozone lamp as the cold cathode ultraviolet lamp body 22 and 32 and using an ozone-less quartz tube or a barium silica-based ultraviolet transparent soft glass as the outer tube 21, the outer tube 21 cuts ozone rays. It is also possible to obtain a germicidal lamp.

  The ultraviolet lamp of each embodiment described above can be used in a sterilization / deodorization apparatus built in an air conditioner (air conditioner), an air cleaner or the like.

  Examples of the present invention will be described below.

  In the present embodiment, a dual structure cold cathode ultraviolet lamp having the structure shown in FIG. 1 is manufactured, and the ambient temperature (the ambient temperature of the lamp) in which the lamp is disposed and the intensity of ultraviolet light of 245 nm emitted from the lamp. And the relationship was measured. The outer diameter of the outer tube 21 was 9 mm. The outer tube 21 and the main body 22 are both ozone-less quartz tubes. The space 28 between the outer tube 21 and the main body 22 was an atmospheric atmosphere.

  As a comparative example 1, the outer tube 21 of the double-structure cold cathode ultraviolet lamp in FIG. 1 of the embodiment was removed, and only a single tube cold cathode ultraviolet lamp body 22 was used, and the ambient temperature and ultraviolet radiation of 245 nm were the same as in the example. The relationship with intensity was measured.

  As Comparative Example 2, a cold cathode ultraviolet lamp 1 having the same structure as that of the single-tube cold cathode ultraviolet lamp body 22 used in the example was used, and an outer tube 12 having an outer diameter of 9 mm was arranged on the outer side. A cold cathode ultraviolet lamp having a double-tube structure was manufactured. The outer tube 21 and the ultraviolet lamp 1 are both ozone-less quartz tubes. The atmosphere in the space between the cold cathode ultraviolet lamp 1 and the outer tube 12 was air. In addition, in order to seal the outer tube 12, the metal foil 3 was disposed also at the sealing portion of the outer tube 12, and heated with a burner or the like. For the cold cathode ultraviolet lamp having the double-tube structure of Comparative Example 2, the relationship between the ambient temperature and the ultraviolet radiation intensity at 245 nm was measured in the same manner as in the example.

  FIG. 10 is a graph showing the relationship between the ultraviolet radiation intensity (245 nm) measured with respect to the cold cathode ultraviolet lamps of Examples and Comparative Examples 1 and 2, and the ambient temperature (atmosphere temperature).

  As is apparent from FIG. 10, the single tube ultraviolet lamp of Comparative Example 1 has an atmospheric temperature of about 60 ° C. at which the ultraviolet radiation of 254 nm is maximized. At this time, the surface temperature of the single-tube ultraviolet lamp was about 40 ° C., and it was confirmed that it almost coincided with the optimum temperature of mercury vapor that maximizes the ultraviolet radiation efficiency of 254 nm.

  On the other hand, both the ultraviolet lamp of the example and the double-tube ultraviolet lamp of Comparative Example 2 showed a maximum of 254 nm ultraviolet radiation in the range of about 30 ° C. to 50 ° C. This is due to the heat insulation effect of the double tube, and the fluctuation of mercury vapor pressure inside the cold cathode ultraviolet lamp body 22 of the example and the ultraviolet lamp 1 inside the comparative example 2 is compared with the single tube of the comparative example 1. This is thought to be due to the decrease.

  Moreover, the ultraviolet radiation intensity of the ultraviolet lamp of the example was lowered in the low temperature region of 20 ° C. or lower as compared with the ultraviolet lamp of comparative example 2. This is because the UV lamp of the example seals the outer tube 21 with a cup-shaped metal cap 25 and silicone resin, etc., so that ozoneless quartz glass is heated and sealed with a burner like the UV lamp of Comparative Example 2. This is probably because the airtightness is slightly inferior to the structure that stops. However, when considering use indoors at 20 ° C. to 30 ° C., a decrease in ultraviolet radiation intensity at 20 ° C. or lower is not a problem at all.

1: Ozone-less quartz glass, 2: Cold cathode, 3: Metal foil, 4: Shaft, 5: Foil sealing structure, 6: Lead wire, 7: Ultraviolet transparent soft glass, 9: Sealed wire, 10: Bead Sealing part, 18: Insertion preference, 21: Outer tube, 22: Cold cathode UV lamp body, 23: Sealing part, 25: Cup type metal cap, 25a: Cylindrical part, 25b: Bottom part, 26: Outer tube and cup 27: Airtight sealing part, 28: Space between cold cathode ultraviolet lamp body and outer tube, 30: Terminal, 31: Hermetic seal type metal cap, 31a: Cylindrical part, 31b: Bottom part, 31c : Insulation part, 32: Hot cathode UV lamp body, 33: Terminal

Claims (5)

An ultraviolet lamp, an outer tube disposed outside the lamp, and a metal cap placed on an end of the outer tube;
The ultraviolet lamp includes a cold cathode and a lead wire connected to the cold cathode, and the lead wire is inserted into an insertion hole provided in the metal cap, and is electrically sealed from the metal cap by a conductive material. A double tube type ultraviolet lamp characterized by being kept and joined.   2. The double-tube ultraviolet lamp according to claim 1, wherein a sealing material is filled between the metal cap and the outer tube and hermetically sealed. .   3. The double tube type ultraviolet lamp according to claim 1, wherein the metal cap has a conical shape around the insertion hole. An ultraviolet lamp, an outer tube disposed outside the lamp, and a metal cap placed on an end of the outer tube;
The ultraviolet lamp has a hot cathode and two lead wires connected to the hot cathode,
The metal cap is provided with two insertion holes arranged side by side, and a cylindrical terminal with one end sealed is inserted into each insertion hole, and the metal cap is disposed around the cylindrical terminal. Insulation material is filled so as to keep airtight between
Two lead wires of the ultraviolet lamp are inserted from the other ends of the two cylindrical terminals and are in electrical contact with the terminals, respectively.   5. The double tube type ultraviolet lamp according to claim 4, wherein the cylindrical terminal has a tapered shape in which the inner diameter gradually decreases as the inner diameter moves away from the ultraviolet lamp. lamp.

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