JP2020047551A - heater - Google Patents

Abstract

To suppress the occurrence of cracks at both ends of an arc tube.SOLUTION: A heater includes an arc tube 2, a multilayer film, a metal foil 12, a lead wire 20, a welding portion 30, and a sealing portion 2a. The arc tube has a heating element 10 provided therein. The multilayer film is formed on the outer peripheral surface of the arc tube. The metal foil is electrically connected to the heating element. The lead wire is electrically connected to the metal foil. The welding portion joins the metal foil and the lead wire. The sealing portion is formed in the arc tube so as to seal the inside of the arc tube such that some of the heating element, the metal foil, the welding portion, and the lead wire are buried. Further, the sealing portion has a lead-out portion 11 from which the lead wire is drawn out of the arc tube.SELECTED DRAWING: Figure 2

Description

  Embodiments of the present invention relate to a heater.

  2. Description of the Related Art A heater used for heating an object to be irradiated by radiant heat is known. Since the heater is required to have anti-glare properties in applications such as space heating and paint drying, a multilayer film having a high visible light blocking effect is formed on the outer surface of the arc tube. The multilayer film is formed by alternately stacking high-refractive-index films and low-refractive-index films in order to transmit infrared light and block visible light.

JP 2005-019317 A

  In the heater as described above, sealing portions are provided at both ends of the arc tube to keep the inside of the arc tube airtight. However, the metal material buried in the sealing portion may expand due to oxidation, and cracks may occur in the sealing portion.

  The problem to be solved by the present invention is to provide a heater that can suppress the occurrence of cracks.

  The heater according to the embodiment includes an arc tube, a multilayer film, a metal foil, a lead wire, a welded portion, and a sealing portion. The arc tube is provided with a heating element inside. The multilayer film is formed on the outer peripheral surface of the arc tube. The metal foil is electrically connected to the heating element. The lead wire is electrically connected to the metal foil. The welding portion joins the metal foil and the lead wire. The sealing portion is formed in the arc tube so that the heating element, the metal foil, the welded portion, and a part of the lead wire are buried, and seals the inside of the arc tube. The sealing portion has a lead-out portion from which the lead wire is drawn out of the arc tube.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a crack can be suppressed.

FIG. 2 is a plan view showing the heater according to the first embodiment. FIG. 2 is a sectional view of FIG. 1 showing the heater according to the first embodiment. FIG. 3 is a diagram illustrating a usage mode of the heater according to the first embodiment. FIG. 6 is a diagram illustrating a heater according to a second embodiment. FIG. 9 is a diagram illustrating a heater according to a modification of the second embodiment.

  A heater 1 according to an embodiment described below includes an arc tube 2, a multilayer film 3, a metal foil 12, a lead wire 20, a welded portion 30 (31), and sealing portions 2a and 2b. . The arc tube 2 has a heating element 10 provided therein. The multilayer film 3 is formed on the outer peripheral surface of the arc tube 2. The metal foil 12 is electrically connected to the heating element 10. Lead wire 20 is electrically connected to metal foil 12. The welding portion 30 (31) joins the metal foil 12 and the lead wire 20. The sealing portions 2 a and 2 b are formed on the arc tube 2 so that the metal foil 12, the welded portion 30 (31), and a part of the lead wire 20 are buried, and seal the inside of the arc tube 2. In addition, the sealing portions 2 a and 2 b have a lead-out portion 11 from which the lead wire 20 is drawn out of the arc tube 2.

  Further, the welded portion 30 (31) according to the embodiment described below includes tantalum or platinum.

  The heater 1 according to the embodiment described below further includes a cement material 21. The cement material 21 is provided on the lead-out portion 11 so as to surround the lead wire 20 drawn out from the lead-out portion 11.

  An embodiment according to the present invention will be described below with reference to the drawings. The embodiments described below do not limit the technology disclosed by the present invention. Further, each embodiment and each modified example described below can be appropriately combined within a consistent range. In the description of each embodiment, the same components are denoted by the same reference numerals, and the description that follows will be omitted as appropriate.

[Embodiment 1]
FIG. 1 is a plan view showing a heater according to the first embodiment. As shown in FIG. 1, the heater 1 according to the first embodiment includes an arc tube 2, a multilayer film 3, a first base 4, a second base 5, a first coating tube 6, a second coating tube 7, and a first external introduction. It has a wire 8, a second external introduction wire 9, and a heating element 10.

  In order to make the description easy to understand, FIG. 1 illustrates a three-dimensional orthogonal coordinate system including a Z-axis having a vertically upward direction as a positive direction and a vertically downward direction as a negative direction. Such an orthogonal coordinate system is also shown in other drawings used in the following description.

  The arc tube 2 is formed of a transparent and non-colored material, and is formed in a cylindrical shape. Examples of the material of the arc tube 2 include quartz glass having a high softening point.

  The multilayer film 3 is formed on the outer peripheral surface of the arc tube 2. The multilayer film 3 includes a plurality of low-refractive-index films and high-refractive-index films. The low refractive index film contains silicon oxide as a main component, and the high refractive index film contains iron oxide as a main component. The multilayer film 3 transmits infrared light out of light emitted from the arc tube 2 and blocks visible light.

The multilayer film 3 is formed by a dipping method, a vacuum evaporation method, a sputtering method, or the like, and about 10 low-refractive-index films and high-refractive-index films are alternately stacked. Specifically, for example, an odd-numbered layer starting from the first layer formed directly on the surface of the arc tube 2 is formed of a low-refractive-index film, and an even-numbered layer starting from the second layer is formed of a high-refractive-index film. Since silicon oxide, specifically, silicon dioxide (SiO ₂ ), which is a main component of the low refractive index film, is close to the component of the arc tube 2, by using the first layer, the adhesion to the surface of the arc tube 2 can be reduced. It can be improved. In addition, since silicon dioxide has excellent chemical and thermal resistance and has mechanical strength, even if it is directly formed on the surface of the arc tube 2 at a high temperature, the possibility of peeling or damage is low. Note that it is also possible to form the odd-numbered layers with a high refractive index film and the even-numbered layers with a low refractive index film. In the multilayer film 3, the uppermost layer farthest from the arc tube 2 may be a high-refractive-index film or a low-refractive-index film.

Iron oxide (Fe ₂ O ₃ ), which is a main component of the high refractive index film, has higher anti-glare properties than silicon oxide. Therefore, by using iron oxide for the high refractive index film, the antiglare property of the heater 1 can be improved. However, iron oxide is different from silicon oxide in the components of the arc tube 2, and thus it is desirable that iron oxide is provided outside the arc tube 2 via a low refractive index film.

The low-refractive-index film is not limited to silicon dioxide, and may have any form as long as it is a silicon oxide such as silicon oxide (SiO). The low-refractive-index film is not limited to silicon oxide, and a metal compound other than silicon oxide such as magnesium fluoride (MgF ₂ ) may be used. The high-refractive-index film is not limited to iron oxide. For example, a metal oxide other than iron oxide such as titanium oxide (TiO ₂ ), niobium oxide (Nb ₂ O ₅ ), and tantalum oxide (Ta ₂ O ₅ ) is used. It may be used.

  The thickness of each layer of the multilayer film 3 may be different from each other, or may be the same for each of the low-refractive-index films and the high-refractive-index films. Further, the thickness of the low-refractive-index film may be larger than that of the high-refractive-index film. Specifically, for example, the thickness of the low-refractive-index film is 80 nm, and the thickness of the high-refractive-index film is 57 nm, but is not limited thereto.

  The heating element 10 is disposed inside the arc tube 2 and is sealed together with an inert gas and a halide (not shown). The heating element 10 is supported by an anchor material (not shown). One end of the heating element 10 is formed to extend to the sealing portion 2 a housed inside the first base 4, and is electrically connected to the first external introduction line 8. On the other hand, the other end of the heating element 10 is formed to extend to the sealing portion 2 b provided inside the second base 5, and is electrically connected to the second external introduction line 9.

  The heating element 10 is a tungsten filament formed in a coil shape. The heating element 10 generates heat and emits light when a voltage is applied from a power supply (not shown) via the first external introduction line 8 and the second external introduction line 9.

  The first external introduction line 8 and the second external introduction line 9 are heat-resistant electric wires whose core wires are covered with, for example, PTFE (polytetrafluoroethylene) or another fluororesin.

  The first external introduction line 8 is covered with the first covering tube 6. The first coating tube 6 improves the insulation of the first external introduction wire 8 inside the first base 4. Similarly, the second external introduction line 9 is covered with the second covering tube 7. The second covering tube 7 improves the insulation of the second external introduction wire 9 inside the second base 5.

  The first base 4 and the second base 5 are members for supporting and fixing the arc tube 2. Specifically, the first base 4 and the second base 5 accommodate sealing portions 2a and 2b provided at both ends of the arc tube 2, and the sealing portions 2a and 2b are fixed. The space between the sealing portion 2a and the first base 4 and the space between the sealing portion 2b and the second base 5 are filled with a filler such as a cement material containing alumina as a main component or silicon, for example. The sealing portions 2a and 2b may be fixed to the first base 4 and the second base 5 with a filler.

  Here, the configuration of the sealing portions 2a and 2b housed inside the first base 4 and the second base 5 will be described in more detail with reference to FIG. FIG. 2 is a sectional view of FIG. 1 showing the heater 1 according to the first embodiment. (A) is AA sectional drawing which looked at the sealing part 2a and its vicinity along X-axis direction, (b) is sectional drawing which carried out the vicinity of sealing part 2a along the Y-axis direction. It is BB sectional drawing. In FIG. 2, the illustration of the first base 4 is omitted. Further, the configuration of the sealing portion 2b housed in the second base 5 and its vicinity is the same as the configuration of the first base 4 and its vicinity shown in FIG. Therefore, illustration and description of the sealing portion 2b are omitted.

  As shown in FIG. 2, a metal foil 12 is buried inside the sealing portion 2a. The sealing portion 2a in the first embodiment is a so-called pinch seal portion formed in a plate shape. Further, the sealing portion 2 a has a lead-out portion 11 which is an opening for drawing out the lead wire 20 connected to the metal foil 12 to the outside of the arc tube 2.

  The metal foil 12 is formed in a rectangular shape by molybdenum. The metal foil 12 is electrically connected to one end 13 of the heating element 10. Further, the metal foil 12 is joined to the lead wire 20 via the welded portion 30 and is electrically connected to the lead wire 20. The lead wire 20 drawn out from the lead-out portion 11 is electrically connected to the first external introduction wire 8 shown in FIG. 1 by, for example, welding.

  Here, a conventional sealing portion 2a having no welding portion 30 will be described. The metal foil 12 and the lead wire 20 are electrically connected by, for example, welding. Oxygen in the air that has entered the inside of the sealing portion 2a from the lead-out portion 11 oxidizes the metal foil 12 at the joint with the lead wire 20 in a high-temperature environment exceeding 350 ° C., for example. The oxidized metal foil 12 expands. Cracks occur in the sealing portion 2a in which the metal foil 12 is embedded due to stress generated by expansion of the metal foil 12. When the generated crack further proceeds, the gas sealed in the arc tube 2 leaks from the sealing portion 2a, and air enters from outside the arc tube 2. When the air enters, the evaporation of the tungsten constituting the heating element 10 is promoted, and the heating element 10 is disconnected, leading to an inconsistency.

  Therefore, in the heater 1 according to the first embodiment, the welding portion 30 is arranged between the metal foil 12 and the lead wire 20. Specifically, the welded portion 30 joins the metal foil 12 and the lead wire 20.

  The welded portion 30 is formed by sandwiching the welded member between the metal foil 12 and the lead wire 20, heating and melting to a temperature equal to or higher than the melting point of the welded member itself, and after heating, radiating heat from the welded portion 30 to solidify. You. The welded portion 30 formed by solidifying the melted welded member joins the metal foil 12 and the lead wire 20. This suppresses expansion of the metal foil 12 and the lead wire 20 due to oxidation in a high-temperature environment. By suppressing the expansion of the metal foil 12, the occurrence of cracks in the sealing portion 2a due to the expansion of the metal foil 12 is suppressed.

  The welding portion 30 according to the first embodiment is, for example, a rod-shaped or linear tantalum. Further, as shown in the figure, the welding member may be bent and disposed between the metal foil 12 and the lead wire 20. Further, as the welding member, for example, a member having a wire diameter of about 0.2 mm can be used. In addition, the welding part 30 is not limited to tantalum, and may include, for example, platinum. Further, the platinum may be so-called molybdenum platinum plating in which, for example, molybdenum material is plated with platinum. In particular, in the heater 1 having a power consumption of 1500 W or more, for example, 2000 W, the welded portion 30 may be formed by platinum or molybdenum platinum plating.

  Further, the heater 1 according to the embodiment may further include a cement material 21. The cement material 21 is provided on the lead-out portion 11 so as to surround the lead wire 20 drawn out from the lead-out portion 11. The cement material 21 is, for example, alumina cement. The cement material 21 can increase the airtightness inside and outside of the lead-out part 11 by closing a small gap between the lead wire 20 and the lead-out part 11. That is, by providing the cement material 21 in the lead-out portion 11, the expansion of the metal foil 12 is suppressed by suppressing oxygen in the environmental atmosphere from entering the inside of the sealing portion 2 a via the lead-out portion 11, Further, it is possible to suppress the occurrence of cracks in the sealing portion 2a due to the expansion of the metal foil 12.

  FIG. 3 is a diagram illustrating a usage mode of the heater according to the first embodiment. (A) illustrates the case where the irradiation direction is horizontal downward, and (b) illustrates the case where the irradiation direction is obliquely downward.

  As shown in FIG. 3A, when the irradiation direction is horizontal downward, the heat that has reached the irradiation target side by the irradiation of the heater 1 enters the first base 4 and the second base 5 from below the heater 1. The contained sealing portions 2a and 2b are heated. For example, in a heater 1 having a power consumption of 1500 W or more, for example, 2000 W, the metal foil 12 buried in the sealing portions 2a and 2b may have a high temperature exceeding 350 ° C., for example, under an installation condition in which sufficient heat radiation cannot be secured. .

  On the other hand, as shown in FIG. 3B, when the irradiation direction is obliquely downward, the heat reaching the irradiation target side by the irradiation of the heater 1 is stored in the first base 4 located above the heater 1. The sealed portion 2a is heated. For example, in the heater 1 having a power consumption of 1500 W or more, for example, 2000 W, the metal foil 12 buried in the sealing portion 2a may have a high temperature exceeding, for example, 350 ° C. in an installation state in which sufficient heat radiation cannot be secured.

  According to the heater 1 according to the first embodiment, the occurrence of cracks in the sealing portions 2a and 2b is suppressed even under the condition where the temperature of the metal foil 12 becomes high.

[Embodiment 2]
FIG. 4 is a diagram illustrating a heater according to the second embodiment. The heater 1 shown in FIG. 4 has the same configuration as the heater 1 according to the first embodiment, except that the heater 1 has a welding portion 31 instead of the welding portion 30.

  The welding portion 31 according to the second embodiment is, for example, platinum in a film or foil shape. Further, as the welding member, for example, a platinum foil having a thickness of about 0.05 mm can be used. The welded portion 31 is not limited to platinum, and may be formed by, for example, tantalum or molybdenum platinum plating. In particular, in the heater 1 having a power consumption of 1500 W or more, for example, 2000 W, the welded portion 31 may be formed by platinum or molybdenum platinum plating. As described above, according to the heater 1 according to the second embodiment, the expansion of the metal foil 12 due to oxidation in a high-temperature environment is suppressed by having the welded portion 31 that joins the metal foil 12 and the lead wire 20. . Further, the occurrence of cracks in the sealing portion 2a due to the expansion of the metal foil 12 is suppressed.

[Modification of Second Embodiment]
FIG. 5 is a diagram illustrating a heater according to a modification of the second embodiment. (A) is the figure which looked at the sealing part 2a from the Y-axis negative direction side. FIG. 2B is a side view of the area surrounded by the two-dot chain line in FIG. The heater 1 shown in FIG. 5 has the same configuration as the heater 1 according to the second embodiment except that the metal foil 12 has a bent portion 12a.

  As shown in FIG. 5, the welding portion 31 and the lead wire 20 are arranged in a portion where the thickness t is increased by having the bent portion 12a. By bending the metal foil 12 in this manner, the cross-sectional area of the metal foil 12 can be increased, and defects such as foil breakage and sealing damage can be suppressed. The heater 1 according to the modification of the second embodiment is particularly used for a high current type heater, but may be used for any current type heater.

  As described above, the heater 1 according to the embodiment includes the arc tube 2, the multilayer film 3, the metal foil 12, the lead wire 20, the welding portion 30 (31), the sealing portion 2a, 2b. The arc tube 2 has a heating element 10 provided therein. The multilayer film 3 is formed on the outer peripheral surface of the arc tube 2. The metal foil 12 is electrically connected to the heating element 10. Lead wire 20 is electrically connected to metal foil 12. The welding portion 30 (31) joins the metal foil 12 and the lead wire 20. The sealing portions 2 a and 2 b are formed in the arc tube 2 so that the heating element 10, the metal foil 12, the welded portion 30 (31), and a part of the lead wire 20 are buried and seal the inside of the arc tube 2. Is done. In addition, the sealing portions 2 a and 2 b have a lead-out portion 11 from which the lead wire 20 is drawn out of the arc tube 2. Thereby, generation of cracks can be suppressed.

  Further, the welded portion 30 (31) according to the embodiment includes tantalum or platinum. This can suppress the occurrence of cracks even in a heater that consumes a large amount of power or is installed in an environment where sufficient heat dissipation cannot be ensured.

  Further, the heater 1 according to the embodiment further includes a cement material 21. The cement material 21 is provided on the lead-out portion 11 so as to surround the lead wire 20 drawn out from the lead-out portion 11. Thereby, generation of cracks can be further suppressed.

  Although several embodiments of the present invention have been described, these embodiments are provided by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Heater 2 Arc tube 2a, 2b Sealing part 3 Multilayer film 4 First base 5 Second base 10 Heating element 11 Outgoing part 12 Metal foil 20 Lead wire 21 Cement material 30, 31 Welding part

Claims (3)

An arc tube having a heating element provided therein;
A multilayer film formed on the outer peripheral surface of the arc tube;
A metal foil electrically connected to the heating element;
A lead wire electrically connected to the metal foil;
A welded portion for joining the metal foil and the lead wire;
The heating element, the metal foil, the welded portion, and a part of the lead wire are embedded in the arc tube so as to seal the inside of the arc tube, and the lead wire is provided outside the arc tube. A sealing part having a lead-out part drawn out to;
A heater comprising:   The heater according to claim 1, wherein the welding portion includes tantalum or platinum. A cement material provided in the lead-out portion so as to surround the lead wire drawn out from the lead-out portion;
The heater according to claim 1, further comprising:

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