JP2018041598A - Planar heating element and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar heating element equipped with a new structure and also to provide a manufacturing method thereof.SOLUTION: Disclosed is a planar heating element 20 constituted by metal having conductivity. The planar heating element 20 is formed using a metal lath 21 equipped with a large number of through-holes 22 which are arranged in a staggered array between metal net line parts 23 in a plan view. The planar heating element whose electric resistance value is controlled can be manufactured by changing the pitch width of strand of the metal lath 21 and size of the through-hole and also changing the thickness and width of the net line part 23 by adding force in the thickness direction with respect to the metal lath 21.SELECTED DRAWING: Figure 1

Description

The present invention relates to a planar heating element and a method for manufacturing the same.

Planar heating elements are used in various fields, and those having various structures have been proposed.
Patent Document 1 discloses a catalyst body in which a clad steel plate made of an iron-chromium-aluminum thin plate and an aluminum foil is used as a heating element, and the heating element is annealed and then a catalyst is supported to form a catalyst layer. In addition, it is disclosed that the heating element is obtained by lathing a clad steel sheet, then applying a corrugation process, and then performing an annealing process to form an alumina film. However, this Patent Document 1 only shows that the heating element is subjected to lath processing (expanding processing) or the like on the clad steel plate, and there is no disclosure about characteristics such as electric resistance value, and it is simply processed. Only the one that uses the metal lath as it is is disclosed.

Patent Documents 2 and 3 disclose that a metal body or the like is used as a carrier and a catalyst body on which a catalyst is supported is used for an air purifier including a deodorizing device, an exhaust gas purifying device, and a V OC removing device. However, the metal lath is merely a catalyst carrier and does not generate heat by itself.

JP 2000-334299 A Japanese Patent Laid-Open No. 2002-191986 JP 2007-236638 A

In view of the above circumstances, an object of the present invention is to provide a planar heating element having a new structure. The present invention also provides a new method for manufacturing a planar heating element, which can control the electrical resistance value during manufacturing, particularly when the same material is used. It is an object of the present invention to provide a method for manufacturing a planar heating element that can manufacture a sheet having a desired electric resistance value only by setting the above conditions.

The present invention relates to a planar heating element composed of a conductive metal, and the planar heating element includes a large number of through-holes arranged in a zigzag arrangement in a plan view between metal mesh portions. It is composed of a metal lath, but it is not simply using a metal lath as a planar heating element, but by means such as adjusting the step width of the strand of the mesh line portion, the size of the through-hole, rolling, etc. The sheet heating element is characterized in that it is a thin metal lath having a thickness of 0.1 mm or less and an electrical resistance value of 5 mm or more with a width 10 mm × length 1000 mm as a measurement unit. By applying a force in the thickness direction such as rolling, the mesh portion is deformed, and the metal lath shape (the shape in which rhombus spaces are arranged in a staggered manner in plan view) is changed. Can provide.

Further, the present invention provides a method for manufacturing a planar heating element composed of a conductive metal, wherein the planar heating element is arranged in a zigzag array in plan view between metal mesh portions. It is formed using a metal lath with a through hole, and the electric resistance value of the heat generating part is controlled by applying a force in the thickness direction to the metal lath to change the thickness of the mesh part. Provided is a method for manufacturing a planar heating element, characterized in that a thin metal lath is obtained.

In particular, the thickness of the mesh portion before applying force in the thickness direction is 0.3 mm or more, and by rolling the metal lath, the mesh portion is changed to a thickness of 0.1 mm or less, and the width The thin metal lath having an electric resistance value of 10Ω × 1000 mm in length as a measurement unit is controlled to be 5Ω or more can be obtained.

The present invention has been able to provide a planar heating element having a new structure.
The present invention has been able to provide a new method for manufacturing a planar heating element, in which the electrical resistance value can be controlled during manufacturing, particularly when the same material is used. In addition, it is possible to provide a method for manufacturing a planar heating element capable of manufacturing a device having a desired electric resistance value only by setting conditions during manufacturing.

(A) The top view of the metal lath before processing which concerns on embodiment of this invention, (B) The top view of a thin metal lath. Explanatory drawing of the metal lath which concerns on embodiment of this invention. Sectional drawing of the planar heating element using the said thin metal lath. (A) Cross-sectional view of a metal foil used in combination with a coplanar heating element, (B) Cross-sectional view of a laminate of the coplanar heating element and the metal foil, (C) In combination with the coplanar heating element Sectional drawing of the other metal foil used. (A) (B) is a principal part cutting perspective view of the metal foil, respectively, (C) (D) is a principal part cutting perspective view of the metal foil which concerns on other embodiment, respectively. (A) The top view of the modification of the metal foil, (B) The top view of the other modification of the metal foil. (A) The perspective view for showing the structure of the coil structure comprised by the same laminated body, (B) The perspective view for showing the flow direction of the fluid with respect to the coil structure comprised by the same laminated body. The top view of the metal lath before processing which concerns on Examples 1-6, and a thin metal lath. An explanatory view showing a graph which shows a result of heating test 1, and a plane shape of each specimen. Explanatory drawing which shows the planar shape of each test body of the heating test 3. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(About planar heating elements)
In the sheet heating element 20 according to the embodiment of the present invention, the heat generating portion is constituted by a metal lath 21. As shown in FIG. 1, this metal lath 21 is provided with a large number of through holes 22 arranged in a staggered arrangement, and is manufactured by lath processing that forms slits in a metal plate and performs expansion processing or the like, and has the same shape. A large number of through holes 22 are provided. The shape of the through hole 22 is generally a rhombus or the like, but may be a rectangular shape such as a rectangular shape and can be changed as appropriate. A portion of the through hole 22 that is not removed constitutes the mesh portion 23.

For the metal lath 21 subjected to the lath processing, the step width of the strand of the mesh line portion and the size of the through hole are adjusted, and the thickness of the mesh wire portion 23 is changed by applying a force in the thickness direction by rolling or the like. By doing so, the thin metal lath 21b whose electric resistance value is controlled is obtained. Hereinafter, in the form for carrying out the invention, when only the metal lath 21 subjected to the thinning process is indicated, it is referred to as a thinned metal lath 21b, and the metal lath 21 that has not been subjected to the thinning process is referred to as a pre-processing metal lath 21a. Okay, when we say without distinguishing both, it is called metal lath 21.
The main structure of the planar heating element 20 is completed by providing an electrode (not shown) or the like at an appropriate position such as the end of the thin metal lath 21b to enable energization.

(Raw metal plate)
The planar heating element 20 can be manufactured by using a metal plate material having a thickness of about 0.03 to 0.1 mm as a material thereof. However, the planar heating element 20 is changed depending on the use of the planar heating element 20 or required heating performance. be able to. The material of the metal lath 21 can be formed of a material having electrical conductivity, but in particular, high electrical property is required for providing heat generation such as iron or an alloy thereof (for example, Fe—Cr—Al alloy having a high specific resistance). It is appropriate to use a metal having resistance.

(Pre-treatment metal lath 21)
The pre-processing metal lath 21a is also called an expanded metal. For example, the metal plate material is expanded (expanded) in a zigzag pattern by using a mold of an expand manufacturing machine, and the cut is rhombus or turtle shell shape. In this embodiment, the mesh opening is referred to as a through hole 22, and the metal portion is referred to as a mesh portion 23. Of the mesh portion 23, the linear portion is referred to as a strand 24, and the portion where the strands 24 intersect with each other is referred to as a bond 25. Further, the distance between the centers in the short direction of the mesh is referred to as SW, the distance between the centers in the long direction of the mesh is referred to as LW, and the step width of the strand is referred to as W. (See FIGS. 1A and 2). The size of the mesh and the lath thickness can be changed as appropriate, and can be carried out in the following ranges.
SW: 1.0-3.0mm
LW: 1.5-6.0mm
W: 0.3-0.8mm
Lath thickness: 0.3-1.0mm

However, as shown in FIG. 2, SW is the distance between the centers in the short direction of the mesh, LW is the distance between the centers in the long direction, and the lath thickness (simply indicated as thickness in FIG. 2) is the metal lath. 21 is a distance from the lower end to the upper end in the thickness direction. The pre-processing metal lath 21a is not only simply formed with a slit in the metal plate material, but also expanded, so that the cross-section of the metal lath 23 inclines in a three-dimensional shape. As shown in FIG. 2, the upper and lower surfaces (left and right surfaces in the figure) are constituted by the corners of the mesh portion 23. Therefore, in principle, contact with others is not a surface contact but a line contact.

(Rolling process)
Applying a force in the thickness direction to the metal lath 21 by, for example, rolling the pre-treatment metal lath 21a to change the thickness and width of the mesh portion 23 to obtain the thin metal lath 21b. it can. As shown in the change from FIG. 1A to FIG. 1B, the thickness of the mesh portion 23 is reduced and the width in plan view is increased by rolling. The thinned metal lath 21b obtained in this manner has a thin flat plate shape with the mesh portion 23 being flat, and the upper and lower surfaces are substantially flat as shown in FIG. Therefore, it becomes surface contact.

(Surface heating element)
An electrode (not shown) or the like is provided on the thin metal lath 21b to complete the planar heating element 20 that can be energized. The planar heating element 20 can change its heat generation performance and performance as a heater by changing its electric resistance value and its surface area. In particular, in comparison with the metal plate material, the electric resistance value can be increased by 4 times or more (preferably 10 times or more). Specifically, the electrical resistance value having a measurement unit of width 10 mm × length 1000 mm was about 1 to 2Ω in the case of a metal plate (iron-chromium-aluminum alloy), but in the case of the thin metal lath 21b, about It was a great surprise for the inventor that the voltage could be increased to 5Ω or more, preferably about 10 to 60Ω. In particular, a material exhibiting about 20 to 40Ω is considered preferable from the viewpoint of a balance between heat generation performance and strength.

Although the size of the mesh of the thin metal lath 21b can be changed as appropriate, it can be carried out in the following range.
SW: 1.0-3.0mm
LW: 1.5-6.0mm
W: 0.3-0.8mm
Lath thickness: 0.03 mm to 0.1 mm or less (particularly preferably 0.03 to 0.07 mm)
The sheet heating element 20 using the thin metal lath 21b has a significantly increased electric resistance value, and can change the electric resistance value depending on the mesh shape of the lath processing and the degree of rolling (thickness after rolling). . Furthermore, the planar heating element 20 using the thin metal lath 21b reduces the power consumption required to obtain the same heating temperature (metal surface temperature) as compared with the metal plate material and the pre-processing metal lath 21a. Thus, a greater temperature increase can be obtained with the same power consumption.

(Application example)
Since the planar heating element 20 according to the present invention can reduce the amount of sunlight shielded by setting the aperture ratio to 70% or more, it can be used as a sheet heater for melting snow used in cold regions, For example, the present invention can be applied to a solar heater panel or a snowmelt sheet heater for a greenhouse. It can also be implemented as a high-efficiency seat heater capable of uniform heating applied to automobile seat heaters, heated seats for motorcycles and bicycle handles, and hot carpets for household use. At that time, since the sheet heating element 20 is energized and used, portions such as the front surface and the back surface that require insulation are subjected to insulation treatment or other insulating sheets are disposed. The thin metal lath 21b has a smaller thickness than the pre-processing metal lath 21a and the shape of the mesh portion 23 is almost flat, so that it has higher flexibility and flexibility than the pre-processing metal lath 21a. Since it is easy to deform | transform into the shape according to the shape of the part to be used, what was illustrated can of course be applied to various other uses. The planar heating element 20 using the thin metal lath 21b can be applied to various uses. At that time, an insulating means such as an electrode, a temperature control means, a wiring, a switch, and an insulating layer is added depending on the use. Can be implemented.

(About metal foil)
Furthermore, the planar heating element 20 according to the present invention can be used in combination with the metal foil 10 according to the development of the present applicant.
The metal foil 10 will be described with reference to FIGS. 4 and 5.

The metal foil 10 includes a corrugated structure portion 11 in which a peak portion 12 and a valley portion 13 are periodically repeated. Although the overall shape of the metal foil 10 is arbitrary, it can be implemented in various shapes such as a web shape continuously extending with a constant width, a rectangular shape, or a circular shape.

In the following description, the web-shaped metal foil 10 will be described as a premise, but can be implemented in various forms.
In the case of the web-like metal foil 10, the ridges 12 and the valleys 13 are alternately arranged in the longitudinal direction, and the direction in which the ridges 12 and the valleys 13 extend extends in the width direction of the web. . Hereinafter, the longitudinal direction will be described as the vertical direction or the front-rear direction, and the width direction will be described as the horizontal direction or the left-right direction. However, these descriptions only indicate a relative positional relationship and specify an absolute position. It is not a thing. Further, the longitudinal direction of the web and the direction in which the peak portion 12 and the valley portion 13 extend should not be understood in a fixed manner, and the direction in which the peak portion 12 and the valley portion 13 extend is the width direction of the web. It may be carried out or it may be carried out as inclined with respect to the width direction and the longitudinal direction of the web.

The material of the metal foil 10 can be formed of various materials such as metal and synthetic resin, and in particular, it has self-heating properties such as iron and its alloys (for example, Fe-Cr-Al alloy having high specific resistance). In some cases, it is preferable to use a conductive metal. The plate thickness is preferably about 0.02 to 0.1 mm thin plate (foil) such as 0.05 mm, but can be changed depending on the use.

(About the waveform structure)
The metal foil 10 includes the corrugated structure 11 in which the crests 12 and the troughs 13 are alternately arranged. The corrugated structure 11 can be implemented as being formed on the entire metal foil 10, You may implement as what was formed only in part. When forming only in a part, for example, it may be provided in the central portion of the metal foil 10, the half portion in the width direction, the peripheral portion, or the like.

The peak portion 12 and the valley portion 13 can be implemented as symmetrical in the vertical direction, but the peak portion 12 and the valley portion 13 may have different widths and heights.
In this embodiment, the peak portion 12 and the valley portion 13 have a flat peak top surface 16 and a valley bottom surface 17, and have a substantially trapezoidal cross section in which a slope 18 connects the peak top surface 16 and the valley bottom surface 17. There is no. Note that a corner portion between the mountain top surface 16 and the valley bottom surface 17 and the slope 18 may form a round shape, and the trapezoidal shape should not be understood to be limited to a geometric meaning. Since the top surface 16 and the bottom surface 17 of the valley are flat, an effect of increasing the contact area with the planar heating element 20 can be exhibited.

(Incision and protrusion)
The metal foil 10 includes an incision 14 and a projecting piece 15 in the corrugated structure 11.
The incision 14 and the projecting piece 15 can be formed by appropriate means, but can be formed by, for example, burring processing on the metal foil 10.

Specifically, it can be implemented as a burr formed by performing a burring process, and a plurality of protruding pieces 15 can be formed for one incision 14. The projecting pieces 15 are separated and protrude from each other, and at least their tips are independent from each other (note that the projecting pieces 15 may be connected to each other at their bases, but the tips are independent from each other. And a flow space 19 exists between the projecting pieces 15, and a fluid represented by a gas such as air flows from the flow space 19 between the projecting pieces 15 to the thickness of the metal foil 10. It can flow in the direction (inside and outside).

Each protrusion 15 protrudes toward the inside of the corrugated structure 11. Since the corrugated structure 11 has a plate shape as a whole, the inside and outside meanings are only relative, but the corrugated structure 11 is divided into two by a virtual line between the peak 12 side and the valley 13 side. The projecting piece 15 on the mountain portion 12 side protrudes into a space defined by the virtual line and the mountain portion 12, and the projecting piece 15 on the valley portion 13 side is defined by the virtual line and the valley portion 13. It can be implemented as protruding into the space to be made. In other words, it is assumed that the projecting piece 15 does not protrude above the mountain top surface 16 and the projecting piece 15 does not project below the valley bottom surface 17. Thereby, due to the synergistic effect of the above-described substantially flat mountain top surface 16 and valley bottom surface 17, as shown in FIG. can do. Moreover, the effect of not damaging the material of the other party that abuts can also be exhibited.

About the formation position of the incision part 14 and the protrusion piece 15, as shown in FIG. 4 (A), FIG. 5 (A) and FIG. 5 (B), the incision part 14 and the protrusion piece 15 are connected to the mountain top surface 16 or the valley bottom surface. 17 and not on the inclined surface 18, and as shown in FIGS. 4 (C), 5 (A) and 5 (B), the incision 14 and the projecting piece 15 are formed. The upper surface 16 or the bottom surface 17 of the valley and the inclined surface 18 can be formed continuously.

The projecting piece 15 can be variously changed depending on the structure of the mold or the like, but can be implemented as two projecting pieces 15 projecting from two places before and after the incision 14, and projecting from three or more of the incision 14. It can also be implemented as a projecting piece 15. Further, the shape of the incision 14 in plan view may be a rectangle, or a circle or an ellipse.

The projecting piece 15 can also be formed by a method other than burring. For example, the incision 14 can be incised with a blade and the surplus portion thereof can be bent.
The metal foil 10 can be used as a carrier for supporting a catalyst, or can be used as a heating element by using a metal having high electrical resistance.

The metal foil 10 as a carrier can be used as a carrier carrying a catalyst for purifying air contaminated with automobile exhaust gas or PM discharged from a factory or the like. In this case, as the catalyst component, for example, a platinum group catalyst such as platinum (Pt) or palladium (Pd), or an active component such as vanadium (V), molybdenum (Mo), or tungsten (W) mainly composed of titanium oxide. What added the component can be used, and if necessary, a heat resistant oxide layer such as alumina (Al ₂ O ₃ ) can be formed on the surface of the metal lath 21 to support the catalyst.

In any case, the fluid flow around the metal foil 10 (the thickness direction of the metal foil 10 and the longitudinal direction of the corrugated structure 11) is kept good, and the contact area with the planar heating element 20 is increased. Preferably, the structure of the metal foil 10 described above presents a structure suitable for this. In particular, since the protruding piece 15 protrudes inside the peak portion 12 or the valley portion 13, the protruding piece 15 and the mountain top surface 16 exist in a space limited by the mountain top surface 16 or the valley bottom surface 17 and the slope 18. The occurrence of fluid turbulence can be promoted, and the shape of the incision 14 and the projecting piece 15 appropriately controls the flow of fluid in both the thickness direction of the metal foil 10 and the longitudinal direction of the corrugated structure 11. Therefore, it is possible to improve the fluid flow, the contact time with the fluid, and the contact area.

(Application example as a laminate)
The metal foil 10 and the planar heating element 20 can be used as a laminate 30 in which both are combined.
The metal foil 10 and the planar heating element 20 can be used in a state where they are not joined to each other (including both the states where they are not in contact), or the metal foil 10 and the planar heating element 20. Can be used in a state of being joined together, and a structure in which these states are combined and the metal foil 10 and the planar heating element 20 are stacked in the thickness direction is referred to as a laminated body 30. However, the form which arrange | positioned the planar heat generating body 20 with respect to the metal foil 10 in any one of the upper and lower sides, and the form arrange | positioned at both can be taken.

(The form in which the metal foil and the planar heating element are not joined)
As will be described below, the metal foil 10 and the planar heating element 20 can be implemented as being joined together, but can also be implemented as a form in which the two are not joined. As a form in which the two are not joined, the metal foil 10 and the planar heating element 20 are in contact with each other (particularly in the case of having a substantially flat mountain top surface 16 or valley bottom surface 17). However, it does not matter even if there is a space between the two without bringing them into contact (including surface contact). However, when it implements in the state made to contact, the effect which the above-mentioned protrusion 15 protrudes inside can be exhibited effectively.

(Metal foil and planar heating element joined together)
The form in which the metal foil 10 and the planar heating element 20 are joined is one in which both are integrated by a joining means, and constitutes one non-separated sheet structure. Any joining means may be used as long as both are integrated, but brazing or welding can be shown as a suitable example. When performing these joining means, the metal foil 10 and the planar heating element 20 need to be a metal that can be brazed or welded. At this time, as described above, the projecting piece 15 has a corrugated structure. The metal foil 10 and the planar heating element 20 can be brought into surface contact with each other by projecting toward the inside of the portion 11 and the top surface 16 and the bottom surface 17 of the mountain being substantially flat. It is possible to suppress brazing and welding defects. Examples of other joining means include joining with a fastening body such as a screw or rivet, adhesion with an adhesive, fixing with various tapes, and the like, and various joining means can be used in combination.
In addition, when joining the metal foil 10 and the planar heating element 20, brazing etc. can also be implemented only in the part. At this time, as shown in FIG. 6 (A), when both side edges in the width direction of the web-shaped metal foil 10 are brazed to the planar heating element 20, the incised portion 14 is formed in the brazed portion 33. Further, the brazing area can be further increased by not forming the projecting pieces 15. In addition, the area | region which does not form this incision part 14 or the protrusion 15 can be implemented in various changes, such as providing in the center of the width direction of the web-shaped metal foil 10 (refer FIG.6 (B)).
As will be described later, when the metal foil 10 and the planar heating element 20 are overlapped and wound in a coil shape, they can be wound together in advance, but in advance, considering the difference in the peripheral ratio between them. Wrapping may be performed without joining, and brazing may be performed by placing a brazing agent on the end face formed into a coil after completion of winding. Moreover, when joining the same person after completion of winding, it is also possible to stop both by joining both at the end of winding and at the inner periphery.

In addition, when joining the metal foil 10 and the planar heating element 20, brazing etc. can also be implemented only in the part. At that time, when both side edges of the web-shaped metal foil 10 in the width direction are brazed to the planar heating element 20, the incised portion 14 and the projecting piece 15 are not formed in the brazed portion. The attachment area can be further increased. In addition, the area | region which does not form this incision part 14 or the protrusion 15 can be implemented in various changes, such as providing in the center of the width direction of the web-shaped metal foil 10. FIG.

(Operation effect of the laminated body 30)
Regardless of the presence or absence of the above-mentioned joining, in addition to the advantages of the metal foil 10 as a single body, the laminated body 30 can exhibit a synergistic effect with the planar heating element 20.
In the relationship between the laminated body 30 and the surrounding fluid, the space is further limited by the presence of the sheet heating element 20 in addition to the mountain top surface 16 or the valley bottom surface 17 and the slope 18. At that time, when the planar heating element 20 does not allow or restricts the passage of fluid, the movement of the fluid between the stacked bodies 30 can be restricted. On the other hand, when the through holes 22 are provided, fluid movement between the stacked bodies 30 can be allowed. At that time, due to the presence of the flow space 19 between the projecting pieces 15 and the incision 14, the movement of the fluid between the stacked bodies 30 can be sufficiently ensured. In particular, when fluid movement between the stacked bodies 30 is required, or when it is advantageous to have fluid movement between the stacked bodies 30, it is preferable to provide the through holes 22.

(Specific usage of laminate)
The metal foil 10 can carry the catalyst as described above, and can be used as the laminated body 30 that overlaps the planar heating element 20 in the thickness direction. For example, the laminate 30 can be used as a flat sheet structure, but can also be implemented as a coil structure 31 wound in a spiral as shown in FIG. it can.

As a specific application example, an example in which the metal foil 10 is applied to a metal carrier can be shown. Further, the catalyst can be supported on both the metal foil 10 and the planar heating element 20.
At that time, after the catalyst is supported on at least one of the metal foil 10 and the planar heating element 20, they may be overlapped and wound in a spiral shape. If the catalyst is carried on both of the planar heating elements 20 after being wound on each other, the risk of damage to the catalyst carried during processing such as winding can be eliminated.
In any case, since both the metal foil 10 and the planar heating element 20 have through portions in the thickness direction, fluid flows across a plurality of layers in the radial direction of the coil structure 31. It can also flow and promotes three-dimensional fluid movement.

In addition, the metal foil 10 and the planar heating element 20 may not be joined but may be joined. When the top surface 16 and the bottom surface 17 of the metal foil 10 are substantially flat and the projecting piece 15 projects inward, the planar heating element 20 is not damaged, and when joining, It is possible to suppress brazing and welding defects.

The winding direction is such that one end side in the longitudinal direction of the web is the inner peripheral end and the other end side is the outer peripheral end. In other words, the direction in which the peak portion 12 and the valley portion 13 extend is the width direction of the web. What is necessary is just to wind so that it may correspond to the axial direction of 31 substantially. As a result, a fluid can flow from one end surface in the axial direction of the coil structure 31 to the other end surface (from the lower surface to the upper surface in FIG. 7B), and the fluid that has flowed moves from the one end surface to the other end surface. Inside, it can move also to the peripheral direction of layered product 30, and turbulent fluidization can be promoted.

The laminate 30 can be applied to various gas purification devices such as an exhaust gas purification device, a PM removal device, and a deodorization device, and can also be applied to various heating devices. More specifically, the present invention can also be implemented as a combined unit in which the heating unit and the purification unit in the air purification device of Japanese Patent Application Laid-Open No. 2015-223579 related to the application of the present applicant are integrated. Moreover, as an application example as a heater, a superheated steam generator can be shown, and the laminated body 30 is adopted as an electric heater provided with electrodes, and steam is directly heated to generate superheated steam. Can be implemented. In this example, the water vapor can be directly heated by passing the water vapor from one end surface of the coil structure 31 to the other end surface, the size can be reduced, and the heating efficiency can be improved. It is.

Examples are shown below to enhance the understanding of the present invention, but the present invention should not be understood to be limited to these Examples.
In Examples 1 to 6, six kinds of pre-treatment metal laths 21a were manufactured by applying different lath processing to a metal plate material of one type of material, and six types of thinned metal laths 21b were obtained by rolling each of them. Is.

(Raw metal plate)
The common metal plate material of each example was used. Specifically, a plate material made of an alloy (Fe-18% Cr-3% Al) having a plate thickness of 0.05 mm, a length of 1 m, and a width of 80 mm was used.

(Metal lath before processing)
The metal plate material was spread while being cut in a zigzag pattern by a mold of an expand manufacturing machine, and a substantially rhombic mesh-like plate material was obtained. Table 1 shows the design dimensions of the six types (Examples 1 to 6) of the molds and the measured values of the pre-treatment metal lath 21a obtained thereby. The meaning of each dimension is as shown in the embodiment.

(Thinned metal lath)
Six types of pre-treatment metal laths 21a were rolled to obtain thin metal laths 21b (Examples 1 to 6) each having a thickness of 0.05 mm. In FIG. 8, the top view (photograph) of the metal lath 21a before processing which concerns on Examples 1-6 and the thin metal lath 21b is shown. Table 2 shows the electrical resistance value (resistance value (Ω)) of the thin metal lath 21b according to Examples 1 to 6 together with the ratio of the electrical resistance value of the metal plate material. The electrical resistance values were measured by providing electrodes at both ends in the longitudinal direction with respect to those having a width of 10 mm, a length of 1000 mm, and a thickness of 0.05 mm.
Thus, the thin metal lath of the example was able to increase the electric resistance value from about 4 times to nearly 30 times compared to the raw material.

(Heating test 1)
As the heating test 1, a heating test was performed on the thin metal lath 21b (sample 1) according to Example 3, the pre-treatment metal lath 21a (sample 2), and the metal plate material (sample 3). The results are shown in Table 3 and FIG. In Table 3, as a reference example, the result of an unprocessed plate material made of SUS + Cu (0.03 mm thick) is also shown.
In this heating test 1, each of the specimens 1 to 3 and the reference example was made to have a substantially M-shaped planar shape shown in FIG. The measured power and heat generation temperature (surface temperature) were measured.
Specimen 1 required 10.9 w of power to reach a surface temperature of 60 ° C, while Specimen 2 required 15.2 w of power to reach a surface temperature of 59 ° C. In the thin metal lath 21b (specimen 1), the same heat generation effect can be obtained by the power consumption of about two-thirds compared to the pre-treatment metal lath 21a (specimen 2). Was made. Further, when the specimen 3 and the reference example are compared with the specimen 1, the difference is clear.
Therefore, in the present invention, compared with the metal plate material and the pre-processing metal lath 21a, it is possible to reduce the power consumption required to obtain the same heat generation temperature (metal surface temperature) and the same consumption. It was confirmed that a larger temperature increase can be obtained with the amount of electric power.

(Heating test 2)
As the heating test 2, a heating test using the thin metal lath 21b according to Example 3 was performed. The results are shown in Table 4.
In this heating test 2, two types of thin metal laths 21b according to Example 3 having a width of 40 mm and different lengths (large: electrical resistance value 5Ω, small: electrical resistance value 7Ω) were prepared, and the electrodes And was energized. The room environment at the start of the heating test was room temperature 24.3 ° C. and humidity 46%. The surface temperature of Example 3 was measured when 10 seconds had passed after energization, and the results are shown in Table 4. When a voltage of 12 V was applied, the temperature rose to 41 ° C. and 31 ° C. after 10 seconds. It was shown that the larger the electrical resistance value, the lower the power consumption and the lower the temperature rise.

(Heating test 3)
As the heating test 3, the heating test using the thin metal lath 21b according to Example 1, Example 3, and Example 4 was performed. The conditions and results are shown in Table 5 and FIG.
This heating test 3 was performed with the following four types of patterns.

Pattern 1: Three types of voltages of 6V, 8V, and 12V were applied to a thin metal lath 21b according to Example 1 that was used as it was and had a width of 80 mm and a length of 980 mm.

Pattern 2: For the thin metal lath 21b according to Example 1 having a width of 80 mm and a length of 980 mm, slits having a length of 40 mm were alternately provided from both sides facing each other at intervals of 40 mm. Three types of voltages of 6V, 8V, and 12V were applied.

Pattern 3: Using the thin metal lath 21b according to Example 1 and having a width of 80 mm × a length of 980 mm, slits having a length of 50 mm and a width of 10 mm were alternately provided from both sides facing each other at intervals of 30 mm. About three, the voltage of 6V, 8V, and 12V was applied.

Pattern 4: Using the thin metal lath 21b according to Example 3 and Example 4 and having a width of 40 mm × a length of 280 mm, two of Example 3 and those of Example 4 Were connected in series in a ring and a voltage of 12V was applied.
The room environment at the start of the heating test was room temperature 27.0 ° C and humidity 50%. Table 5 shows the results of measuring the surface temperatures of Examples 1, 3 and 4 of each pattern when 10 seconds passed after energization.

In comparison between Pattern 1 and Patterns 2 and 3, it was considered that the one provided with the slit was considered to have a larger electric resistance value, and the larger the resistance value, the lower the power consumption and the lower the temperature rise.

DESCRIPTION OF SYMBOLS 10 Metal foil 11 Corrugated structure part 12 Mountain part 13 Valley part 14 Incision part 15 Projection piece 16 Mountain top surface 17 Valley bottom surface 18 Slope 19 Distribution space 20 Planar heating element 21 Metal lath 21a Metal lath 21b before processing Thin metal lath 22 Through-hole 23 Network Wire part 24 Strand 25 Bond 30 Laminate 31 Coil structure

Claims (3)

In a planar heating element composed of a conductive metal,
The planar heating element is constituted by a metal lath having a large number of through holes arranged in a zigzag arrangement in a plan view between metal mesh portions,
The mesh portion has a thickness of 0.1 mm or less,
A planar heating element characterized by having an electric resistance value of 5Ω or more with a measurement unit of width 10 mm × length 1000 mm. In the method for manufacturing a planar heating element composed of a conductive metal,
The planar heating element is formed using a metal lath having a large number of through-holes arranged in a staggered arrangement in plan view between metal mesh portions,
By changing the step width of the strand of the mesh line portion and the size of the through-hole, and applying a force in the thickness direction to the metal lath to change the thickness of the mesh line portion, the electrical resistance value is changed. A method for producing a planar heating element, comprising obtaining a controlled thinned metal lath and forming the planar heating element with the thinned metal lath. The thickness of the mesh line part of the metal lath before applying force in the thickness direction is 0.3 mm or more, and by rolling the metal lath, the thickness of the mesh line part is changed to 0.1 mm or less. 3. The method of manufacturing a planar heating element according to claim 2, wherein the thin metal lath having an electrical resistance value of 5 Ω or more with a measurement unit of width 10 mm × length 1000 mm is obtained.