JP2007103294A - Infrared bulb and heating device - Google Patents

Abstract

An object of the present invention is to reduce stress generated between a heat generating portion and a holding portion in a heating element, prevent disconnection and breakage due to repeated on / off operation, and provide a safe and long-life infrared bulb and heating. An object is to provide an apparatus.
An infrared light bulb and a heating device according to the present invention include a heat generating element having a small heat generating region having a small cross-sectional shape perpendicular to the current path, a heat buffer region formed on both sides of the heat generating region, and a heat generating region. A holding region having a large cross-sectional shape orthogonal to the current path direction of the current path, connected through the thermal buffer region, and holding the cross-sectional shape orthogonal to the current path direction of the current path in the thermal buffer region from the heat generation region side It gradually increases as you go to the area side.
[Selection] Figure 1

Description

  The present invention relates to an infrared light bulb used as a heat source for heating means in various devices, and more particularly to an infrared light bulb using a carbon-based material as a heating element and a heating device using the infrared light bulb.

As a heat source in various devices such as electric stoves, cookers, dryers, copiers, facsimiles, printers, etc., for example, a carbon system obtained by adding a resistance adjusting substance of nitrogen compound and amorphous carbon to a crystallized carbon base material such as graphite An infrared light bulb using a heating element in which a substance is formed into a rod shape or a plate shape is widely used (see, for example, Patent Document 1).
In addition, development of infrared bulbs using carbon fiber as a heating element is underway. For example, a heating element has been developed in which a carbonized layer is formed by applying a resin to the surface of carbon fiber and firing it, and the heat generation characteristics can be adjusted without impairing flexibility (see, for example, Patent Document 2). .)
JP 2001-351762 A Japanese Patent Laid-Open No. 2001-257058

As described above, as a heating element of a conventional infrared light bulb, a material containing a carbon-based material such as crystallized carbon, amorphous carbon, or carbon fiber is used. Recently, in order to reduce the current path for the purpose of reducing the size and increasing the heat generation, such heating elements have been processed such as cuts, slits, and holes.
By applying the above-mentioned processing to narrow the current flow path to the heating element, the heating element easily breaks due to thermal stress in addition to expansion and contraction operations due to expansion during heat generation and contraction when heat generation stops. There was a problem in terms of durability due to the structure. In particular, in infrared light bulbs using carbon fiber, since the resistance value of the carbon fiber serving as a heating element is low, a device has been devised to increase the resistance value by forming a thin and long current flow path, particularly in terms of durability. There was a problem.
As described above, in the conventional infrared bulb, between the heating element having a narrow and long current flow path and the holding part that holds the heating element, the heating element expands when the heating element generates heat and stops heating. There has been a problem that disconnection or breakage occurs due to expansion and contraction due to contraction and thermal stress. Therefore, it has been desired to develop a heating element having excellent durability in an apparatus using an infrared light bulb as a heat source.

  An object of the present invention is to solve the problems in conventional infrared light bulbs, to reduce the thermal stress generated between the heat generating portion and the holding portion of the heating element, and to prevent disconnection or breakage due to repeated ON / OFF operation of the power source. An object of the present invention is to provide an infrared light bulb and a heating device that prevent generation and have a long life.

In order to solve the conventional problems and achieve the above object, the infrared light bulb according to the first aspect of the present invention includes:
A heating element having a substantially strip shape extending in the longitudinal direction;
Holding means electrically connected to both end portions in the longitudinal direction of the heating element;
An insulating tube enclosing the heating element and the holding means;
Lead means electrically connected to the holding means and led out from the insulating tube,
The heating element is connected to a heating area formed at a central portion of the heating element, a thermal buffer area formed on both sides of the heating area, and the heating area via the thermal buffer area. A cross-sectional shape orthogonal to the current path direction has a holding region larger than the heat generation region, and a cross-sectional shape orthogonal to the current path direction of the current path in the thermal buffer region goes from the heat generation region side to the holding region side. It is configured to gradually increase according to. In the infrared light bulb of the present invention configured as described above, the stress generated between the heat generating portion and the holding portion of the heat generator is reduced, and disconnection and breakage due to repeated ON / OFF operation of the power source are prevented. .

  The infrared light bulb according to the second aspect of the present invention may have a configuration in which the heat generation region of the heating element according to the first aspect has a meandering shape.

  In the infrared light bulb according to the third aspect of the present invention, the joining portion of the heat generating region and the heat buffering region of the heat generating element in the first and second aspects is formed in the vicinity of the side surface side of the heat generating element. It may be configured.

  In the infrared light bulb according to the fourth aspect of the present invention, the junction between the heat generating region and the heat buffering region of the heating element in the first and second aspects is on a center line parallel to the longitudinal direction of the heating element. The structure formed in may be sufficient.

  The infrared light bulb according to the fifth aspect of the present invention may have a configuration in which an opening is formed in the heat buffer region of the heating element according to the first aspect and the second aspect.

  The infrared light bulb according to the sixth aspect of the present invention may have a configuration in which the heat buffer region of the heating element according to the first aspect and the second aspect is formed by a curved surface.

  The infrared light bulb according to the seventh aspect of the present invention may have a configuration in which the inner edge of the opening is formed by a curved surface in the heat buffering region of the heating element according to the first and second aspects.

  In the infrared light bulb according to the eighth aspect of the present invention, the heating element according to the first aspect and the second aspect may include a carbon-based material.

  The infrared light bulb according to the ninth aspect of the present invention may be configured such that the heating element according to the first aspect and the second aspect includes a carbon-based material and a resistance adjusting material.

  The infrared light bulb according to the tenth aspect of the present invention may have a configuration in which the heating element according to the first aspect and the second aspect is formed of a mixture containing at least one of crystallized carbon and amorphous carbon.

  The infrared light bulb according to the eleventh aspect of the present invention may have a configuration in which the heating element according to the first aspect and the second aspect includes carbon fiber.

  In the infrared light bulb according to the twelfth aspect of the present invention, the heating element according to the first aspect and the second aspect may be composed of a woven fabric, a nonwoven fabric, or a felt made of carbon fiber.

  The infrared light bulb according to the thirteenth aspect of the present invention may have a configuration in which the heating element according to the first aspect and the second aspect is formed by being filled with conductive particles as a soft filler.

  The infrared light bulb according to the fourteenth aspect of the present invention may have a configuration in which graphite or carbon black is filled as conductive particles of the soft filler according to the thirteenth aspect.

  The infrared light bulb of the fifteenth aspect of the present invention has a configuration in which a non-volatile oligomer or polymer compound, or a mixture thereof is filled as the soft filler of the heating element in the first and second viewpoints. good.

  The infrared light bulb according to the sixteenth aspect of the present invention may have a structure filled with starch, polyethylene, carboxymethylcellulose, or a mixture thereof as the soft filler of the heating element in the first and second aspects.

  The infrared light bulb according to the seventeenth aspect of the present invention may have a configuration in which a heat dissipating part having thermal conductivity is provided at a joint portion with the heating element in the holding means according to the first and second aspects.

  In an infrared light bulb according to an eighteenth aspect of the present invention, the insulating tube according to the first aspect and the second aspect is made of quartz, glass, ceramics, cordierite, mullite, alumina, zirconia, magnesia, calcia, and silica. A configuration including at least one selected from the group may be used.

  The infrared light bulb according to the nineteenth aspect of the present invention may have a configuration in which an inert gas is sealed in the insulating tube according to the first and second aspects.

A heating device according to a twentieth aspect of the present invention includes the infrared light bulb according to the first aspect to the nineteenth aspect, and a control means for controlling power supply to the infrared light bulb. In the heating device of the present invention configured as described above, the stress generated between the heat generating part and the holding part in the heating element of the infrared light bulb is reduced, and disconnection and breakage due to repeated ON / OFF operation of the power source are caused. Is prevented.

  The heating device according to a twenty-first aspect of the present invention is disposed on the front side of the heating device so that the plane side of the belt-like heating element in the infrared bulb according to the twentieth aspect faces the object to be heated, and the rear surface of the infrared light bulb A configuration in which a reflecting means is provided on the side may also be used.

  According to the present invention, the stress generated between the heat generating portion and the holding portion in the heat generating element is reduced, the occurrence of disconnection and breakage due to repeated ON / OFF operation of the power source is prevented, and the infrared ray with high reliability and long life is achieved. It is possible to provide a light bulb and a heating device.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an infrared light bulb and a heating device according to the invention will be described with reference to the accompanying drawings.

Embodiment 1
FIG. 1 is a front view showing the structure of the infrared light bulb according to Embodiment 1 of the present invention. In FIG. 1, the infrared light bulb according to Embodiment 1 has a belt-like shape as a whole, and a heating element 1 having a meandering shape at the center thereof, and holding means 10 that holds both ends of the heating element 1 are insulating tubes. The inside of the glass tube 2 is accommodated and an inert gas 9 is enclosed. Lead means 11 is connected to each holding means 10, and a part of the lead means 11 is led out from both ends of the glass tube 1 to the outside.

  As shown in FIG. 1, the holding means 10 is elastic to the holding members 3a and 3b connected to both ends of the heating element 1, and the heat dissipating parts 4a and 4b wound around the outer peripheral surfaces of the holding members 3a and 3b. And spring portions 5a and 5b. The lead means 11 is embedded in the internal lead wires 6a and 6b connected to the spring portions 5a and 5b, the external lead wires 8a and 8b led out to the outside of the glass tube 2, and the sealed portion of the glass tube 2. It is constituted by molybdenum foils 7a and 7b for connecting the lead wires 6a and 6b and the external lead wires 8a and 8b. The heat radiating portions 4a and 4b, the spring portions 5a and 5b, and the internal lead wires 6a and 6b are integrally formed of a metal wire such as molybdenum or tungsten.

  The holding members 3a and 3b have a cylindrical shape, and a slit is formed at one end so that the end of the heating element 1 can be sandwiched. Both end portions of the heating element 1 are inserted into slits formed at one end of the holding members 3a and 3b and fixed by an adhesive. The holding members 3a and 3b have a function of radiating heat from the heating element 1, and are made of a material having high conductivity and high thermal conductivity, such as graphite. The holding members 3a and 3b are configured to radiate heat from the heating element 1 and suppress heat conduction to the coil-like heat radiating portions 4a and 4b. The holding members 3a and 3b are inserted and fixed into heat radiation portions 4a and 4b formed by spirally forming a metal wire having elasticity such as molybdenum or tungsten. The heat radiating portions 4a and 4b are tightly wound around the outer peripheral surfaces of the holding members 3a and 3b, and both are electrically connected. The heat radiating portions 4a and 4b are connected to the internal lead wires 6a and 6b through elastic spring portions 5a and 5b. By providing the spring portions 5a and 5b between the internal lead wires 6a and 6b and the heat radiating portions 4a and 4b, the dimensional change due to the expansion of the heating element 1 can be absorbed.

  The heating element 1 is formed of a fibrous carbon material having a graphite crystal structure. The heating element 1 of Embodiment 1 is made of PAN-based carbon fiber, which is obtained by subjecting resin fibers to flame resistance treatment and carbonization treatment, and is composed of a woven carbon fiber band made of warp and weft. Yes. The heating element 1 is obtained by applying an additive to a woven fabric in which a plurality of warp yarns and a plurality of weft yarns are woven in a lattice shape, and firing. The dimensions of the heating element 1 are, for example, a band width of 7 mm, a band thickness of 1.2 mm, and a length of 400 mm. It is desirable that the heating element 1 has a ratio of the band thickness to the band width of 1: 5 or more. By making the band width larger than the band thickness, the heat emitted from the surface having the band width becomes larger than the heat emitted from the surface having the band thickness, and the heating element 1 as the heat source can radiate heat having directivity.

  In the infrared light bulb of the first embodiment, the heating element 1 is formed in a meandering shape at the central portion other than both sides thereof. That is, a plurality of cuts (slits) are alternately formed in the direction orthogonal to the longitudinal direction of the heat generating element 1 from both side surfaces (upper and lower side surfaces of the heat generating element 1 in FIG. 1) inward. The innermost position of this cut is formed beyond the longitudinal center line of the heating element 1. By configuring the heating element 1 in a meandering shape in this manner, the resistance value of the heating element 1 formed of carbon fiber can be set to a desired value, and the amount of heat from the heating element 1 is set to a predetermined value. It becomes possible.

Next, the heating element 1 in the infrared light bulb according to the first embodiment of the present invention will be described. FIG. 2 is an enlarged front view of the vicinity of a region surrounded by a circle A in the heating element 1 shown in FIG.
As shown in FIGS. 1 and 2, the heating element 1 has a meandering heating region 1A, a heat buffering region 1B formed on both sides thereof, and a holding region 1C formed on the outside thereof. Has been. 1 A of heat_generation | fever area | regions are comprised by the heat generating part 1a arrange | positioned in the center part of the heat generating body 1, and the electric current path | route is formed thinly so that resistance value may become large by meander shape. The holding region 1C is a portion that is sandwiched between the holding members 3a and 3b, and includes a holding portion 1c. The heat buffer region 1B is a region connecting the heat generating region 1A and the holding region 1C, and is configured by the heat buffer portion 1b. The thermal buffer 1b has a thermal buffering function that gradually cools and transmits the heat generated in the heat generating area 1A to the holding area 1C without direct conduction.

  As described above, the heating element 1 in the infrared light bulb according to the first embodiment generates a predetermined amount of heat with a small heat source, and thus forms a plurality of cuts (slits) at alternate positions in the shape of the heat generating portion 1a. The meandering shape can be increased. Therefore, the heat generating portion 1a through which a predetermined current flows becomes a high temperature, and a large amount of heat flows into the heat buffering portion 1b connected to the heat generating portion 1a. The heat buffer 1b is connected to the holding portion 1c and receives a stress such as vibration from the holding portion 1c.

  As shown in FIG. 2, the heat buffering portion 1b of the heating element 1 in the infrared light bulb according to the first embodiment has a length perpendicular to the longitudinal direction of the heating element 1 (left and right direction in FIG. 2) (Length in the direction) is gradually increased toward the end of the heating element 1. That is, the cross-sectional area perpendicular to the longitudinal direction of the heat buffering portion 1b is formed so as to gradually increase from the heat generating portion 1a toward the holding portion 1c. Moreover, in the heat generating body 1 in Embodiment 1, the meandering heat-generating part 1a and the heat buffer part 1b are comprised in the lowest end part.

  In the heating element 1 configured as described above, the cross-sectional shape gradually increases in the heat buffering region 1B from the thin part of the heat generating part 1a to the thick part (thickness is substantially the same) of the holding part 1c. A smooth current path is formed. As shown in FIG. 2, in the heat buffer region 1B from the heat generating region 1A to the holding region 1C, all corner portions are formed with smooth curved surfaces. In the first embodiment, the corner portions in the heat generating portion 1a of the heat generating region 1A are shown as being formed at substantially right angles, but these corner portions may also be formed in a curved surface.

  Since the heating element 1 in the infrared light bulb according to the first embodiment is configured as described above, the resistivity of the heating region 1A is high, and the resistivity gradually decreases in the heat buffering region 1B. It is configured to have the lowest resistivity. As a result, the temperature gradually decreases in the heat buffer region 1B of the heating element 1, and the occurrence of thermal stress can be suppressed. In addition, in the infrared light bulb of the first embodiment, it is possible to prevent the occurrence of a failure such as disconnection or breakage of the heating element 1 due to the repetition of the ON / OFF operation of the power source. Therefore, the infrared light bulb of the first embodiment can provide an infrared light bulb with high reliability and a long life, and it becomes possible to improve the safety and reliability of the heating device using this infrared light bulb. A long-life heating device can be realized.

  In the infrared light bulb of the first embodiment, the heat radiating portions 4a and 4b and the spring portions 5a and 5b in the holding means 10 have been described as examples provided on both sides of the heating element 1, but the present invention has such a configuration. For example, a configuration in which the heat dissipating portion and the spring portion of the holding means are provided only on one side of the heating element has the same effect as that of the configuration of the first embodiment.

  In addition, although the heating element 1 in the infrared light bulb according to the first embodiment has been described as an example formed of a fibrous carbon material having a graphite crystal structure, crystallized carbon such as graphite, a resistance value adjusting material, and amorphous carbon You may form with the carbonaceous material which consists of a mixture of these.

  Moreover, although the heating element 1 in the infrared light bulb according to the first embodiment has been described with the example of the carbon fiber strip in the woven state made of warp and weft, it is made of woven fabric, non-woven fabric, or felt made of carbon fiber. Can be used.

  The heating element 1 in the infrared light bulb of Embodiment 1 is configured by filling conductive particles such as graphite or carbon black as a soft filler. In addition, the soft filler of the heating element 1 may be filled with a non-volatile oligomer or polymer compound, or a mixture thereof, or starch, polyethylene, carboxymethyl cellulose, or a mixture thereof is filled as the soft filler of the heating element. You may do it.

  As described in the example using the glass tube 2 as the insulating tube in the infrared light bulb of the first embodiment, any material selected from quartz, glass, ceramics, cordierite, mullite, alumina, zirconia, magnesia, calcia, and silica An insulating tube formed using can be used.

<< Embodiment 2 >>
FIG. 3 is a front view showing the structure of the infrared light bulb according to the second embodiment of the present invention. The infrared light bulb according to the second embodiment is different from the infrared light bulb according to the first embodiment shown in FIG. 1 only in the structure of the heating element, and the other structures are the same. Therefore, in the infrared light bulb of the second embodiment described below, the same reference numerals are given to the components having the same functions and configurations as the elements in the first embodiment, and the description of the first embodiment is applied to the description.
As shown in FIG. 3, the heating element 12 of the infrared light bulb according to the second embodiment has a belt-like shape as a whole, a heating part 12 a having a meandering shape at the center, and a heat buffering part 12 b connected to the heating part 12 a. The holding portion 12c is sandwiched between the holding members 3a and 3b. The heat generating body 12 in the second embodiment is different from the heat buffering section 1b in the first embodiment in the shape of the heat buffering section 12b that connects the heat generating section 12a and the holding section 12c.

Hereinafter, the heating element 12 in the infrared light bulb of the second embodiment will be described. FIG. 4 is an enlarged front view showing the vicinity of a region surrounded by a circle B in the heating element 12 shown in FIG.
As shown in FIGS. 3 and 4, the heating element 12 according to the second embodiment includes a meandering heat generating region 12A, a heat buffer region 12B formed on both sides thereof, and a holding region 12C formed on the outer side thereof. It is comprised. The heat generating region 12A is configured by a heat generating portion 12a disposed in the central portion of the heat generating body 12, and a current path is formed narrow so that the resistance value increases due to the meandering shape. The holding region 12C is a portion sandwiched between the holding members 3a and 3b, and includes a holding portion 12c. The heat buffer region 12B is a region that connects between the heat generating region 12A and the holding region 12C, and includes a heat buffer portion 12b. The thermal buffering part 12b has a thermal buffering function that gradually cools and transmits the heat generated in the heat generation area 12A to the holding area 12C without direct conduction.

  Since the heating element 12 in the infrared light bulb of the second embodiment generates a predetermined amount of heat with a small heat source, the heating part 12a has a meandering shape in which a plurality of cuts (slits) are formed at alternate positions to increase the resistance value. It has a shape. Therefore, the heat generating part 12a through which a predetermined current flows becomes a high temperature, and a large amount of heat flows into the heat buffering part 12b connected to the heat generating part 12a. Further, the heat buffering part 12b is connected to the holding part 12c and has a structure that receives stress such as vibration from the holding part 12c.

  As described above, the heat buffering portion 12b of the heating element 12 in the infrared light bulb of the second embodiment has a length orthogonal to the longitudinal direction of the heating element 12 (the left-right direction in FIG. 4), as shown in FIG. The length in the vertical direction in FIG. 4 is gradually increased toward the end of the heating element 12. That is, the cross-sectional area perpendicular to the longitudinal direction of the heat buffering portion 12b is formed so as to gradually increase from the heat generating portion 12a toward the holding portion 12c. Moreover, in the heat generating body 12 in Embodiment 2, the meandering heat generating part 12a and the heat buffering part 12b are connected to each other at an intermediate position (an intermediate part in the vertical direction of the heat generating part 12a in FIG. 4). ing.

  In the heat generating element 12 configured as described above, the cross-sectional shape gradually increases in the heat buffering region 12B from the thin portion of the heat generating portion 12a to the thick portion (thickness is substantially the same) of the holding portion 12c. A smooth current path is formed. As shown in FIG. 4, the heat buffer region 12B from the heat generating region 12A to the holding region 12C is formed by a smooth curved surface. In the second embodiment, the corner portions in the heat generating portion 12a of the heat generating region 12A are shown as being formed at substantially right angles, but these corner portions may also be formed in a curved surface.

  Since the heating element 12 in the infrared light bulb of the second embodiment is configured as described above, the resistivity of the heat generating region 12A is high, and the resistivity gradually decreases in the heat buffering region 12B. It is configured to have the lowest resistivity. As a result, the temperature gradually decreases in the heat buffer region 12B of the heating element 12, and generation of thermal stress can be suppressed. Further, in the infrared light bulb of the second embodiment, the heat generating part 12a and the heat buffering part 12b are configured to be connected at an intermediate position (position on the longitudinal center line in the heat generating element 12). There exists an effect which suppresses generation | occurrence | production of the twist in the heat generating body 12 resulting from the expansion-contraction by thermal expansion. Furthermore, in the infrared light bulb of the second embodiment, it is possible to prevent the occurrence of a failure such as disconnection or breakage of the heating element 12 due to repeated ON / OFF operation of the power source. Therefore, in the infrared light bulb of the second embodiment, it is possible to provide an infrared light bulb with high reliability and a long life, and it becomes possible to improve the safety and reliability of the heating device using this infrared light bulb, A long-life heating device can be realized.

  In the infrared light bulb of the second embodiment, the holding means 10 has been described as being provided on both sides of the heating element 12, but the present invention is not limited to such a configuration. Even if the coil portion and the spring portion are provided only on one side of the heating element, the same effects as those in the configuration of the second embodiment described above can be obtained.

<< Embodiment 3 >>
FIG. 5 is a front view showing the structure of the infrared light bulb according to the third embodiment of the present invention. The infrared light bulb of Embodiment 3 is different from the infrared light bulb of Embodiment 1 shown in FIG. 1 described above only in the structure of the heating element, and the other structures are the same. Therefore, in the infrared light bulb of the third embodiment described below, the same reference numerals are given to the components having the same functions and configurations as the elements in the first embodiment, and the description of the first embodiment is applied to the description.

  As shown in FIG. 5, the heating element 13 of the infrared light bulb according to the third embodiment has a belt-like shape as a whole, a heating part 13 a having a meandering shape at the center, and a thermal buffer part 13 b connected to the heating part 13 a. And a holding portion 13c sandwiched between the holding members 3a and 3b. The heat generating body 13 in the third embodiment is different from the heat buffer section 1b in the first embodiment in the shape of the heat buffer section 13b that connects the heat generating section 13a and the holding section 13c.

Hereinafter, the heating element 13 in the infrared light bulb of Embodiment 3 will be described. FIG. 6 is an enlarged front view showing the vicinity of a region surrounded by a circle of C in the heating element 13 shown in FIG.
As shown in FIGS. 5 and 6, the heating element 13 in the third embodiment includes a meandering heat generating region 13A, a heat buffer region 13B formed on both sides thereof, and a holding region 13C formed on the outer side thereof. , And is configured. The heat generating region 13A is configured by a heat generating portion 13a disposed in the central portion of the heat generating element 13, and a current path is formed narrow so that the resistance value increases due to the meandering shape. The holding region 13C is a portion sandwiched between the holding members 3a and 3b, and includes a holding portion 13c. The heat buffer area 13B is an area connecting the heat generating area 13A and the holding area 13C, and is configured by the heat buffer portion 13b. The heat buffering part 13b has a heat buffering function that gradually cools and transmits the heat generated in the heat generating area 13A to the holding area 13C without direct conduction.

  The heating element 13 in the infrared light bulb according to the third embodiment generates a predetermined amount of heat with a small heat source. Therefore, the shape of the heating part 13a is formed in a staggered position so that a plurality of cuts (slits) can be formed to increase the resistance value. It has a shape. Therefore, the heat generating portion 13a through which a predetermined current flows becomes a high temperature, and a large amount of heat flows into the heat buffering portion 13b connected to the heat generating portion 13a. The heat buffer 13b is connected to the holding portion 13c and receives a stress such as vibration from the holding portion 13c.

  In the heat generating body 13 in Embodiment 3, the meandering heat generating portion 13a and the heat buffering portion 13b are connected at the lower end position (the lower end portion in the vertical direction of the heat generating portion 13a in FIG. 6). As shown in FIG. 6, an opening 13 d is formed in the heat buffer portion 13 b of the heating element 13 of Embodiment 3, and two upper and lower current paths are formed. The opening 13d has a substantially trapezoidal shape, and is formed such that its bottom side is in the direction of the heat generating part 13a and its top side is in the direction of the holding part 13c. For this reason, the upper and lower current paths formed in the heat buffer portion 13b have a cross-sectional area perpendicular to the longitudinal direction (left and right direction in FIG. 6) gradually increasing from the heat generating portion 13a toward the holding portion 13c. is doing.

In the heat generating element 13 configured as described above, the cross-sectional shape gradually increases in the heat buffer region 13B from the thin current path of the heat generating part 13a to the thick current path (thickness is substantially the same) of the holding part 13c. An increasing current path is formed.
As shown in FIG. 6, the trapezoidal opening 13 d formed in the heat buffer portion 13 b is formed with a smooth curved surface at the corner portion of the inner surface edge. In the third embodiment, the corner portions in the heat generating portion 13a of the heat generating region 13A are shown as being formed at substantially right angles, but these corner portions may also be formed in a curved surface.

  Since the heating element 13 in the infrared light bulb according to the third embodiment is configured as described above, the resistivity of the current path in the heating area 13A is high, and the resistivity of the current path goes outward in the thermal buffer area 13B. Accordingly, the resistivity of the current path in the holding region 13C is the lowest, and the resistivity is the lowest. As a result, the temperature gradually decreases in the heat buffer region 13B of the heating element 13, and the occurrence of thermal stress can be suppressed. Further, in the infrared light bulb according to the third embodiment, it is possible to prevent the occurrence of a failure such as disconnection or breakage of the heating element 13 due to the repetition of the ON / OFF operation of the power source. Therefore, the infrared light bulb of the third embodiment can provide an infrared light bulb with high reliability and a long life, and it is possible to improve the safety and reliability of a heating device using this infrared light bulb. A long-life heating device can be realized.

In the infrared light bulb of the third embodiment, the holding means 10 has been described as being provided on both sides of the heating element 13, but the present invention is not limited to such a configuration. Even if the coil portion and the spring portion are provided only on one side of the heating element, the same effects as those in the configuration of the third embodiment described above can be obtained.
Further, the shape of the opening 13d formed in the heat buffering portion 13b is not limited to the substantially trapezoidal shape shown in FIG. Included in the invention. FIG. 7 is another example of the infrared light bulb of the third embodiment, and is a plan view showing a part of the heating element 14 in an enlarged manner. A heating element 14 shown in FIG. 7 shows a region corresponding to the heating element 13 shown in FIG.

  As shown in FIG. 7, the opening 14d of the heat buffering part 14b in the heating element 14 has a substantially isosceles triangular shape, and is formed so that the bottom side becomes the heating part 14a and the apex side becomes the holding part 14c. For this reason, in the two upper and lower current paths in the heat buffering portion 14b, the cross-sectional area perpendicular to the longitudinal direction (the left-right direction in FIG. 7) gradually increases from the heat generating portion 14a toward the holding portion 14c. Yes. The heating element 14 shown in FIG. 7 is formed on the outer side of the meandering heating area 14A, the heat buffering area 14B formed on both sides thereof, similarly to the heating element 13 shown in FIG. Holding region 14C. In the infrared light bulb shown in FIG. 7 configured as described above, the opening 14d of the thermal buffer portion 14b is formed in a substantially isosceles triangle, so that a desired current path is formed, and the infrared light bulb shown in FIG. Has the same effect as.

<< Embodiment 4 >>
FIG. 8 is a front view showing the structure of the infrared light bulb according to Embodiment 4 of the present invention. The infrared light bulb of the fourth embodiment is different from the infrared light bulb of the first embodiment shown in FIG. 1 described above only in the structure of the heating element, and the other structures are the same. Therefore, in the infrared light bulb of the fourth embodiment described below, the same reference numerals are given to the components having the same functions and configurations as the elements in the first embodiment, and the description of the first embodiment is applied to the description.

  As shown in FIG. 8, the heating element 15 of the infrared light bulb according to the fourth embodiment has a belt-like shape as a whole, a heating part 15a having a meandering shape at the center thereof, and a heat buffering part 15b connected to the heating part 15a. And a holding portion 15c sandwiched between the holding members 3a and 3b. The heat generating body 15 in the fourth embodiment is different from the heat buffering section 1b in the first embodiment in the shape of the heat buffering section 15b that connects the heat generating section 15a and the holding section 15c.

Hereinafter, the heating element 15 in the infrared light bulb of the fourth embodiment will be described. FIG. 9 is an enlarged front view showing the vicinity of a region surrounded by a circle D in the heating element 15 shown in FIG.
As shown in FIGS. 8 and 9, the heating element 15 in the fourth embodiment includes a meandering heat generating region 15A, heat buffering regions 15B formed on both sides thereof, and a holding region 15C formed on the outer side thereof. , And is configured. The heat generating region 15A is configured by a heat generating portion 15a disposed in the central portion of the heat generating body 15, and a current path is formed narrow so that the resistance value increases due to the meandering shape. The holding region 15C is a portion sandwiched between the holding members 3a and 3b, and includes a holding portion 15c. The heat buffer region 15B is a region that connects between the heat generating region 15A and the holding region 15C, and includes a heat buffer portion 15b. The heat buffering part 15b has a heat buffering function that gradually cools and transmits the heat generated in the heat generating region 15A to the holding region 15C without being directly conducted.

  The heating element 15 in the infrared light bulb of the fourth embodiment generates a predetermined amount of heat with a small heat source, and therefore the heat generating portion 15a has a meandering shape in which a plurality of cuts (slits) are formed at alternate positions to increase the resistance value. It has a shape. Therefore, the heat generating portion 15a through which a predetermined current flows becomes a high temperature, and a large amount of heat flows into the heat buffering portion 15b connected to the heat generating portion 15a. The heat buffer 15b is connected to the holding portion 15c and receives a stress such as vibration from the holding portion 15c.

  In the heating element 15 according to the fourth embodiment, the meandering heat generating part 15a and the heat buffering part 15b are located on the center line in the longitudinal direction (left and right direction in FIG. 9) (the intermediate position in the vertical direction of the heat generating part 15a in FIG. 9). ). As shown in FIG. 9, an opening 15 d is formed in the heat buffer portion 15 b of the heating element 15 of the fourth embodiment. The opening 15d has a substantially trapezoidal shape, and is formed so that the bottom side is in the direction of the heat generating portion 15a and the top side is in the direction of the holding portion 15c. For this reason, the upper and lower two current paths formed in the heat buffer portion 15b have a cross-sectional area perpendicular to the longitudinal direction (left and right direction in FIG. 9) gradually from the heat generating portion 15a toward the holding portion 15c. It is increasing.

In the heating element 15 configured as described above, the cross-sectional shape gradually increases in the thermal buffer region 15B from the thin current path of the heat generating part 15a to the thick current path (thickness is substantially the same) of the holding part 15c. An increasing current path is formed.
As shown in FIG. 9, the trapezoidal opening 15 d formed in the heat buffer portion 15 b is formed with a smooth curved surface at the corner portion of the inner surface edge. In the fourth embodiment, the corner portions in the heat generating portion 15a of the heat generating region 15A are shown as being formed at substantially right angles, but these corner portions may also be formed in a curved surface.

  Since the heating element 15 in the infrared light bulb according to the fourth embodiment is configured as described above, the resistivity of the current path in the heat generating area 15A is high, and the resistivity of the current path goes outward in the heat buffer area 15B. The resistance of the current path in the holding region 15 </ b> C is the lowest and gradually decreases. As a result, the temperature gradually decreases in the heat buffer region 15B of the heating element 15, and the occurrence of thermal stress can be suppressed. Further, in the infrared light bulb of the fourth embodiment, the heat generating part 15a and the heat buffering part 15b are configured to be connected at an intermediate position (position on the longitudinal center line of the heat generating element 15). There exists an effect which suppresses generation | occurrence | production of the twist in the heat generating body 15 resulting from the expansion-contraction by thermal expansion. Furthermore, in the infrared light bulb of the fourth embodiment, it is possible to prevent the occurrence of a failure such as disconnection or breakage of the heating element 15 due to the repetition of the ON / OFF operation of the power source. Therefore, the infrared light bulb according to the fourth embodiment can provide an infrared light bulb with high reliability and a long life, and it is possible to improve the safety and reliability of a heating device using this infrared light bulb. A long-life heating device can be realized.

In the infrared light bulb of the fourth embodiment, the holding means 10 has been described as being provided on both sides of the heating element 15, but the present invention is not limited to such a configuration. Even if the coil portion and the spring portion are provided only on one side of the heating element, the same effects as in the configuration of the fourth embodiment described above can be obtained.
Further, the shape of the opening 15d formed in the heat buffering portion 15b is not limited to the substantially trapezoidal shape shown in FIG. 9, and the shape of the cross section of the current path in the heat buffering portion 15b may be gradually increased. Are included in the present invention. FIG. 10 is another example of the infrared light bulb according to the fourth embodiment, and is a plan view showing an enlarged part of the heating element 16. A heating element 16 shown in FIG. 10 shows an area corresponding to the heating element 15 shown in FIG.

  As shown in FIG. 10, the opening 16d of the heat buffering portion 16b in the heating element 16 has a substantially isosceles triangular shape, and is formed so that the bottom side thereof becomes the heating portion 16a and the apex side becomes the holding portion 16c. For this reason, the cross-sectional area orthogonal to the longitudinal direction (left-right direction in FIG. 10) in the two upper and lower current paths in the heat buffering portion 16b gradually increases from the heat generating portion 16a toward the holding portion 16c. . The heating element 16 shown in FIG. 10 is formed on the outer side of the serpentine heating area 16A, the heat buffering areas 16B formed on both sides thereof, like the heating element 15 shown in FIG. Holding region 16C. In the infrared light bulb shown in FIG. 10 configured as described above, a desired current path is formed by forming the opening 16d of the heat buffer portion 16b in a substantially isosceles triangle, and the infrared light bulb shown in FIG. Has the same effect as.

  As specifically described in the first to fourth embodiments, the infrared light bulb according to the present invention reduces the thermal stress between the heat generating portion and the holding portion and repeats the power on / off operation. It can be widely used as a heat source for heating devices, such as electric stoves, cookers, dryers, copiers, facsimiles, printers, etc. .

<< Embodiment 5 >>
FIG. 11 is a perspective view showing the heating device according to the fifth embodiment of the present invention. The heating apparatus of the fifth embodiment shown in FIG. 11 is an apparatus that can be used in any configuration of the infrared light bulb described in the first to fourth embodiments.
The heating device of the fifth embodiment includes an infrared light bulb 17 as a heat source, a reflecting plate 18 that reflects heat rays emitted from the back side of the infrared light bulb 17 and radiates substantially parallel to the front side, The control unit 19 is connected to a power source and controls the input current of the infrared light bulb 17.

  As described above, in the infrared light bulbs described in the first to fourth embodiments, since the heating element has a substantially band shape, the amount of heat radiated from the plane side of the band is radiated from the side surface side. Therefore, the heating element is disposed so that the plane side of the heating element is the front side and the back side of the heating device. Therefore, in the heating device of the fifth embodiment, the heat rays radiated from both the flat surfaces of the heating element are reliably radiated from the front side of the heating device.

  In the heating device of the fifth embodiment, the reflector 18 is disposed on the back side of the infrared light bulb 17, but an infrared light bulb in which a reflective film is directly formed on the back surface of the insulating tube of the infrared light bulb 17 is used. It is also possible to configure a heating device that does not require a reflector.

  Since the heating device of the fifth embodiment configured as described above uses the infrared light bulb described in the first to fourth embodiments, it becomes a heat source control device that facilitates highly accurate temperature management. Further, according to the configuration of the fifth embodiment, since the occurrence of breakage, deformation, torsion, etc. caused by stress or the like in the heating element of the infrared light bulb 17 is suppressed, reliability that does not cause an accident such as a failure occurs. And a long-life heating device. Furthermore, according to the configuration of the fifth embodiment, since the infrared light bulb has a structure capable of absorbing vibrations and shocks even when vibrations and impacts are applied to the heating device, a highly safe heating device Can be provided.

  The heating device of the present invention is not limited to the configuration of the fifth embodiment, and various devices that require a heat source for reliably radiating heat in a desired direction, such as an electric stove, a cooker, and a dryer. Application to a copying machine, facsimile, printer, etc. makes it possible to improve the functions and characteristics of each apparatus.

  The present invention can be applied to apparatuses using an infrared light bulb as a heat source, for example, various apparatuses such as an electric stove, a cooking device, a dryer, a copying machine, a facsimile machine, and a printer.

The front view which shows the structure of the infrared bulb of Embodiment 1 which concerns on this invention The front view which expanded and showed a part of heat generating body in Embodiment 1. FIG. The front view which shows the structure of the infrared bulb of Embodiment 2 which concerns on this invention The front view which expanded and showed a part of heat generating body in Embodiment 2. FIG. The front view which shows the structure of the infrared bulb of Embodiment 3 which concerns on this invention The front view which expanded and showed a part of heat generating body in Embodiment 3. FIG. The front view which expanded and showed a part of heat generating body of the other structure in Embodiment 3. FIG. The front view which shows the structure of the infrared bulb of Embodiment 4 which concerns on this invention The front view which expanded and showed a part of heat generating body in Embodiment 4. FIG. The front view which expanded and showed a part of heat generating body of the other structure in Embodiment 4. FIG. The perspective view which shows the heating apparatus of Embodiment 5 which concerns on this invention.

Explanation of symbols

1, 12, 13, 14, 15, 16 Heating element 1a, 12a, 13a, 14a, 15a, 16a Heating part 1b, 12b, 13b, 14b, 15b, 16b Heat buffer part 1c, 12c, 13c, 14c, 15c, 16c Holding part 1A, 12A, 13A, 14A, 15A, 16A Heat generation area 1B, 12B, 13B, 14B, 15B, 16B Thermal buffer area 1C, 12C, 13C, 14C, 15C, 16C Holding area 2 Glass tube 3a, 3b Holding Member 4a, 4b Heat radiation part 5a, 5b Spring part 6a, 6b Internal lead wire 7a, 7b Molybdenum foil 8a, 8b External lead wire 9 Inert gas 10 Holding means 11 Lead means 13d, 14d, 15d, 16d Opening 17 Infrared light bulb 18 Reflector 19 Control unit

Claims (21)

A heating element having a substantially strip shape extending in the longitudinal direction;
Holding means electrically connected to both end portions in the longitudinal direction of the heating element;
An insulating tube enclosing the heating element and the holding means;
Lead means electrically connected to the holding means and led out from the insulating tube,
The heating element is connected to a heating area formed at a central portion of the heating element, a thermal buffer area formed on both sides of the heating area, and the heating area via the thermal buffer area. A cross-sectional shape orthogonal to the current path direction has a holding region larger than the heat generation region, and a cross-sectional shape orthogonal to the current path direction of the current path in the thermal buffer region goes from the heat generation region side to the holding region side. Infrared light bulb configured to grow gradually according to.   The infrared light bulb according to claim 1, wherein the heat generating area of the heat generating body has a meandering shape.   The infrared light bulb according to claim 1 or 2, wherein a joint portion between the heat generating region and the heat buffering region in the heat generating element is formed in the vicinity of a side surface of the heat generating element.   The infrared light bulb according to claim 1 or 2, wherein a joint portion between the heat generating area and the heat buffering area in the heat generating element is formed on a center line parallel to a longitudinal direction of the heat generating element.   The infrared light bulb according to claim 1, wherein an opening is formed in a heat buffer region of the heating element.   The infrared light bulb according to claim 1 or 2, wherein the heat buffering region in the heating element is formed by a curved surface.   The infrared light bulb according to claim 1 or 2, wherein an inner edge of the opening is formed by a curved surface in the heat buffering region of the heating element.   The infrared light bulb according to claim 1, wherein the heating element includes a carbon-based material.   The infrared light bulb according to claim 1 or 2, wherein the heating element includes a carbon-based material and a resistance adjusting material.   The infrared light bulb according to claim 1 or 2, wherein the heating element is formed of a mixture containing at least one kind of crystallized carbon and amorphous carbon.   The infrared light bulb according to claim 1, wherein the heating element is formed including carbon fiber.   The infrared light bulb according to claim 1 or 2, wherein the heating element is made of carbon fiber woven fabric, non-woven fabric, or felt.   The infrared light bulb according to claim 1 or 2, wherein the heating element is formed by filling conductive particles as a soft filler.   The infrared light bulb according to claim 13, wherein conductive particles of the soft filler are filled with graphite or carbon black.   The infrared light bulb according to claim 1 or 2, wherein a non-volatile oligomer or polymer compound or a mixture thereof is filled as the soft filler of the heating element.   The infrared light bulb according to claim 1 or 2, wherein starch, polyethylene, carboxymethylcellulose, or a mixture thereof is filled as a soft filler of the heating element.   The infrared bulb according to claim 1 or 2, wherein in the holding means, a heat radiating portion having thermal conductivity is provided at a joint portion with the heating element.   The infrared bulb according to claim 1 or 2, wherein the insulating tube includes at least one selected from the group consisting of quartz, glass, ceramics, cordierite, mullite, alumina, zirconia, magnesia, calcia, and silica.   The infrared light bulb according to claim 1 or 2, wherein an inert gas is sealed in the insulating tube. A heating apparatus comprising: the infrared light bulb according to any one of claims 1 to 19; and a control unit that controls supply of power to the infrared light bulb. 21. The heating device according to claim 20, wherein a plane side of a belt-like heating element in the infrared light bulb is disposed on the front side of the heating device so as to face a heating target, and a reflecting means is provided on the back side of the infrared light bulb.

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