Heater device and vehicular sheet

Abstract

To prevent, with simple constitution, abnormal heat generation due to damage of a heat generation layer of a planar heat generation body.SOLUTION: A heater device 20 comprises: planar heat generation bodies 24 which each have a heat generation layer having a carbon material arranged evenly; and a conductive wire 30 which has zigzag parts 32 overlapping the planar heat generation bodies, respectively, and is electrically connected to the planar heat generation bodies 24. Therein when the wire 30 is cut, electricity feeding to the planar heat generation bodies 32 is stopped.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a heater device equipped with a sheet heating element having a heat generating layer in which a carbon material is evenly distributed, and to a vehicle seat equipped with the heater device. [Background technology]

[0002] The heater driving device disclosed in the following Patent Document 1 functions as a power supply control device and controls the power supply to the heating wire. In this heater driving device, a current output circuit and a detection resistor function as a current detection unit and detect the current flowing through the heating wire. A microcomputer repeatedly calculates the heating wire temperature related to the heating wire based on the detected current. The driving circuit functions as a switching unit and turns a switch on or off according to the calculated heating wire temperature. This allows the heating wire temperature to be maintained at an appropriate temperature without placing a temperature detection element near the heating wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-51984 Summary of the Invention [Problem to be solved by the invention]

[0004] As in the above-mentioned prior art, when a heater device has a heating wire, if the heating wire breaks, current stops flowing and no abnormal heat generation occurs. However, in a heater device equipped with a sheet heating element (e.g., a carbon nanotube film heater) having a heating layer in which carbon material is evenly distributed, even if damage such as a cut or hole occurs in part of the sheet heating element, electricity will flow to the undamaged part. For this reason, there is a possibility that abnormal heat generation will occur at the end of the damaged area.

[0005] As a measure to prevent the abnormal heat generation as described above, for example, the heater device's base fabric is thickened to increase the strength of the heater device, thereby preventing cuts and holes, but this does not provide a fundamental solution to the abnormal heat generation that occurs when cuts or holes are made. Another measure is to place a planar temperature sensor near the planar heating element to detect the temperature rise when a cut or hole is made, and cut off the power supply to the heater device using a control device, but this causes a significant increase in the manufacturing cost of the heater device.

[0006] In consideration of the above, an object of the present invention is to provide a heater device capable of preventing abnormal heat generation due to damage to the heat generating layer of a sheet heating element with a simple configuration, and a vehicle seat equipped with the heater device. [Means for solving the problem]

[0007] The heater device of the first embodiment comprises a sheet-shaped heating element having a heating layer in which carbon material is evenly distributed, and a conductive wire having an overlapping portion arranged overlapping the sheet-shaped heating element and electrically connected to the sheet-shaped heating element, and when the wire is cut, current to the sheet-shaped heating element is cut off.

[0008] The "carbon material" in the first embodiment includes carbon nanotubes, carbon fibers, carbon black, graphene, and the like.

[0009] In the heater device of the first aspect, the sheet heating element has a heating layer in which a carbon material is evenly distributed. The conductive wire has an overlapping portion arranged to overlap the sheet heating element and is electrically connected to the sheet heating element. In this heater device, when the heating layer of the sheet heating element is damaged by a blade or the like, the overlapping portion of the wire is cut by the blade or the like, thereby cutting off the flow of electricity to the sheet heating element. This makes it possible to prevent abnormal heating of the sheet heating element with a simple configuration.

[0010] The heater device of the second aspect is the heater device of the first aspect, further comprising a fuse electrically connected in series to the wire.

[0011] In the heater device of the second aspect, when the heat generating layer of the sheet heating element is damaged by a blade or the like, if the overlapping portion of the wire is not cut by the blade or the like, the temperature of the sheet heating element increases, causing the temperature of the wire to rise, and the resistance value of the wire to decrease, thereby increasing the current flowing through the wire. As a result, the fuse electrically connected in series to the wire is blown, cutting off the current to the sheet heating element. This makes it possible to prevent abnormal heat generation of the sheet heating element with a simple configuration, even if the wire is not cut.

[0012] A third aspect of the heater device is the heater device of the first aspect, wherein the wire has thermal conductivity and includes a temperature fuse or a thermostat connected to the wire.

[0013] In the heater device of the third aspect, when the heat generating layer of the sheet heating element is damaged by a blade or the like, if the overlapping portion of the wire is not cut by the blade or the like, the temperature of the sheet heating element increases, causing the temperature of the thermally conductive wire to rise. As a result, the temperature fuse or thermostat connected to the wire is cut by the heat transmitted from the wire, cutting off the current to the sheet heating element. This makes it possible to prevent abnormal heat generation of the sheet heating element with a simple configuration, even if the wire is not cut.

[0014] The heater device of a fourth aspect is any one of the first to third aspects, and comprises a plurality of sheet heating elements, and the wire has a plurality of overlapping portions arranged to overlap each of the plurality of sheet heating elements.

[0015] In the heater device of the fourth aspect, the wire has a plurality of overlapping portions that are arranged to overlap the plurality of sheet heating elements, respectively, so that if any of the sheet heating elements is damaged, the power supply to the sheet heating element is cut off, thereby preventing abnormal heat generation.

[0016] A heater device of a fifth aspect is any one of the first to fourth aspects, wherein the overlapping portion is a zigzag fold portion bent in the zigzag manner.

[0017] In the heater device of the fifth aspect, the zigzag portion of the wire is arranged to overlap the sheet heating element, so that when the heating layer of the sheet heating element is damaged by a blade or the like, the zigzag portion of the wire is easily cut by the blade or the like, and the current to the sheet heating element is easily cut off.

[0018] A sixth aspect of the heater device is the fifth aspect, wherein the zigzag fold portion extends along the direction of current flowing through the planar heating element when energized, and has a plurality of extension portions connected to each other via the zigzag fold bends.

[0019] In the heater device of the sixth aspect, when a cut is made in a sheet heating element having a heating layer in which a carbon material is evenly distributed in a direction intersecting the direction of the current flowing through the sheet heating element, the sheet heating element is more likely to generate more heat than when a cut is made in a direction along the direction of the current. The zigzag portion of the wire material overlapping the sheet heating element extends along the direction of the current and has multiple extensions connected to each other via the zigzag bends. For this reason, when a cut occurs that is likely to increase the heat generated by the sheet heating element as described above, one of the multiple extensions is more likely to be cut, and the current to the sheet heating element is more likely to be cut off.

[0020] A seventh aspect of the heater device is the fifth aspect, wherein the zigzag fold portion extends in a surface direction along the surface of the sheet heating element, and has a plurality of extending portions connected to each other via the zigzag fold bends, and each of the extending portions is bent in a zigzag shape.

[0021] In the seventh aspect of the heater device, the zigzag bends of the wire overlapping the sheet heating element extend in a direction parallel to the surface of the sheet heating element, and each of the zigzag bends has a plurality of extending portions connected to each other via the zigzag bends. This makes it easier for one of the extending portions to be cut off when the sheet heating element is damaged by a blade or the like, and makes it easier to cut off current to the sheet heating element.

[0022] The heater device of the eighth aspect is the fifth aspect, wherein the zigzag fold portion comprises a first zigzag fold portion extending along a first direction along the surface of the planar heating element and having a plurality of first extending portions connected to each other via the zigzag fold bends, and a second zigzag fold portion extending along the surface of the planar heating element and along a second direction intersecting the first direction and having a plurality of second extending portions connected to each other via the zigzag fold bends, and the first zigzag fold portion and the second zigzag fold portion are insulated from each other and arranged overlapping in a direction perpendicular to the surface of the planar heating element.

[0023] In the heater device of the eighth aspect, the zigzag fold of the wire overlapping the sheet heating element has a plurality of first extensions and a plurality of second extensions. The first extensions extend in a first direction along the surface of the sheet heating element, and are connected to each other via the zigzag folds. The second extensions extend in a second direction along the surface of the sheet heating element and intersect with the first direction, and are connected to each other via the zigzag folds. The first zigzag fold and the second zigzag fold are insulated from each other and are arranged overlapping in a direction perpendicular to the surface of the sheet heating element. This makes it easier for either the first extension or the second extension to be cut when the sheet heating element is damaged by a blade or the like, and makes it easier to cut off current to the sheet heating element.

[0024] The vehicle seat of the ninth aspect comprises a sheet heating element having a heat-generating layer in which a carbon material is evenly distributed, a thermally conductive wire having an overlapping portion arranged overlapping the sheet heating element, and a temperature fuse or thermostat electrically connected in series with the sheet heating element and arranged adjacent to a portion of the wire.

[0025] In a ninth aspect of the vehicle seat, the sheet heating element has a heating layer in which a carbon material is evenly distributed. The thermally conductive wire has an overlapping portion arranged to overlap the sheet heating element. The temperature fuse or thermostat is electrically connected in series with the sheet heating element and arranged adjacent to a portion of the wire. In this heater device, when the heating layer of the sheet heating element is damaged by a blade or the like, the temperature of the sheet heating element increases, causing the temperature of the wire to increase. As a result, the temperature fuse or thermostat arranged adjacent to a portion of the wire is cut off by heat transmitted from the wire, and electricity to the sheet heating element is cut off. This makes it possible to prevent abnormal heat generation from the sheet heating element with a simple configuration.

[0026] A vehicle seat of a tenth aspect comprises a seat body having a seat cushion on which a vehicle occupant sits and a seat back supporting the back of the occupant, and a heater device of any one of the first to ninth aspects, in which the sheet-shaped heating element is arranged on the seat body.

[0027] In the vehicle seat of the tenth aspect, the seat body has a seat cushion on which a vehicle occupant sits and a seat back that supports the occupant's back. The seat body is provided with a planar heating element of a heater device. This heater device is any one of the first to ninth aspects, and therefore the above-mentioned effects can be obtained. Effect of the Invention

[0028] As described above, according to the present invention, abnormal heat generation caused by damage to the heat generating layer of the planar heating element can be prevented with a simple configuration. [Brief description of the drawings]

[0029] [Figure 1] 1 is a side view showing a configuration of a vehicle seat according to an embodiment. [Diagram 2] FIG. 1 is a plan view showing a configuration of a heater device according to an embodiment. [Diagram 3]3 is an enlarged plan view showing a part of the configuration shown in FIG. 2. FIG. [Figure 4] 1 is a wiring diagram showing a schematic configuration of a heater device according to an embodiment. [Diagram 5] FIG. 5 is a wiring diagram showing a part of the configuration shown in FIG. [Figure 6] FIG. 6 is a wiring diagram showing a comparative example and corresponding to FIG. 5. [Figure 7] FIG. 13 is a plan view showing an example in which the heater device includes a fuse. [Figure 8A] FIG. 8 is a block diagram showing a schematic configuration of the heater device shown in FIG. 7. [Figure 8B] FIG. 13 is a block diagram showing an example in which a heater device includes a fuse or a thermostat. [Figure 9] FIG. 11 is a wiring diagram showing an example in which a plurality of extending portions of a wire are formed in a zigzag pattern. [Figure 10] FIG. 11 is a wiring diagram showing an example in which the heater device has a current amplification means. [Figure 11] FIG. 11 is a wiring diagram showing an example in which a heater device has an ECU. [Figure 12] 1 is a plan view showing a first fold portion of the wire. FIG. [Figure 13] 13 is a plan view showing a second fold portion of the wire. FIG. [Figure 14] FIG. 2 is a plan view showing the sheet heating element. [Figure 15] 13 is an explanatory diagram for explaining the overlapping of the first zigzag fold portion, the second zigzag fold portion, and the sheet heating element. FIG. [Figure 16] 13 is a plan view showing an example in which a first zigzag fold and a second zigzag fold are connected in series. FIG. [Figure 17] FIG. 11 is a plan view showing an example in which the first zigzag fold and the second zigzag fold are separate circuits. [Figure 18] 13 is a plan view showing an example in which a first zigzag fold and a second zigzag fold are provided on the same substrate. FIG. [Figure 19] FIG. 13 is a plan view showing an example in which the sheet heating element and the wire are not electrically connected. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] A vehicle seat 10 and a heater device 20 according to an embodiment of the present invention will be described below with reference to Figures 1 to 18. Note that arrows FR and UP shown in Figure 1 indicate the front and upper sides of the vehicle seat 10.

[0031] As shown in Fig. 1, a vehicle seat 10 according to this embodiment includes a seat body 12 and a heater device 20. The seat body 12 includes a seat cushion 14 on which a vehicle occupant sits, a seat back 16 that supports the back of the occupant, and a headrest 18 that supports the head of the occupant. The seat cushion 14 is provided with a heater device 20. The heater device 20 is interposed, for example, between the surface layer and the padding material of the seat cushion 14. The heater device 20 may be provided in the seat back 16, or in both the seat cushion 14 and the seat back 16.

[0032] As shown in FIG. 2 and FIG. 3, the heater device 20 includes a base fabric 22, a plurality of sheet heating elements 24 attached to the base fabric 22 by adhesive or other means, and a wire 30 having a plurality of zigzag folds 32 arranged to overlap the plurality of sheet heating elements 24. The plurality of sheet heating elements 24 are electrically connected to each other in series, parallel, or series-parallel. Each sheet heating element 24 has a heating layer in which a carbon material is evenly distributed. Each sheet heating element 24 is a carbon nanotube (CNT) film heater here, and has a carbon nanotube film 26 and a pair of electrodes 28 as shown in FIG. 4. In FIG. 4, only one sheet heating element 24 and one zigzag fold 32 are shown to facilitate understanding of the description.

[0033] In this embodiment, the seat cushion 14 is arranged in the following order from the surface layer side: the skin, the wire 30, the sheet heating element 24, the base material 22, and the padding. By arranging the wire 30 closer to the skin than the sheet heating element 24, when the heat generating layer of the sheet heating element 24 is damaged by a blade or the like, the zigzag portion 32 of the wire 30 is easily cut by the blade or the like, improving safety. Note that the seat cushion 14 may be arranged in the following order from the surface layer side: the skin, the sheet heating element 24, the wire 30, the base material 22, and the padding. In this arrangement, the sheet heating element 24, which is a heat source, is located closer to the occupant than the wire 30, improving heating efficiency. In addition, the wire 30 makes it difficult for an occupant sitting on the seat cushion 14 to feel a foreign body sensation.

[0034] The carbon nanotube film 26 is formed by laminating, for example, a base layer and an insulating layer (both not shown), and a heat generating layer. The base layer and the insulating layer are formed, for example, of polyester, polyethylene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyurethane, polyimide, or polyamide in a film or cloth-like form (including nonwoven fabric). The heat generating layer is formed, for example, of a coating film of carbon nanotubes applied onto the base layer. Carbon nanotubes are carbon crystals with a hollow cylindrical structure, and are heat generating elements that generate heat when current flows through them. The carbon nanotubes are distributed so as to be spread throughout each part of the heat generating layer. In this carbon nanotube film 26, when a vertical or nearly vertical cut is made in the current path, the resistance value increases and a local temperature rise occurs, but even if a horizontal or nearly horizontal cut is made in the current path, the resistance value hardly increases.

[0035] The pair of electrodes 28 is a bus bar formed in a long thin plate shape from a conductive material. The pair of electrodes 28 is opposed to each other in an opposing direction along the surface of the carbon nanotube film 26, and is connected to both ends of the heating layer in the surface direction.

[0036] In the sheet heating element 24 configured as above, when a voltage is applied between the pair of electrodes 28 and a current flows in the heating layer along the above-mentioned opposing direction, if a cut occurs in a direction perpendicular or approximately perpendicular to the current, the resistance value of the heating layer increases significantly, causing a local temperature rise in the heating layer. Also, in this sheet heating element 24, when a voltage is applied between the pair of electrodes 28 and a current flows in the heating layer along the above-mentioned opposing direction, if a cut occurs in a direction parallel or approximately parallel to the current, the resistance value of the heating layer hardly increases, causing no local temperature rise in the heating layer.

[0037] The wire (wiring) 30 is made of a material such as a conductive metal, and has a plurality of zigzag folds 32, each of which is zigzag folded. The zigzag folds 32 correspond to the "overlapped portion" of the present invention. It is preferable that the zigzag folds 32 are zigzag folded at a pitch smaller than the damage caused by a blade or the like piercing the heat generating layer of the planar heating element 24.

[0038] The multiple zigzag folds 32 overlap the multiple sheet heating elements via an insulating layer (not shown). Each zigzag fold 32 is provided on each sheet heating element 24 by means of adhesive, adhesive tape, double-sided adhesive tape, coating, printing, etc. Note that each zigzag fold 32 may be sewn into a base fabric separate from the sheet heating element 24 and configured by bonding, adhesion, coating, printing, etc., and the base fabric may be laminated on the sheet heating element 24.

[0039] Each zigzag fold portion 32 extends along the opposing direction of the pair of electrodes 28 of each sheet heating element 24 (i.e., the direction of current flowing through the sheet heating element 24 when energized), and has a plurality of extending portions 32B connected to each other via zigzag bent portions 32A. Note that the "overlapping portion" in the present invention is not limited to the zigzag fold portion 32, and may be bent in a manner other than zigzag.

[0040] The wire 30 is electrically connected in series to the multiple sheet heating elements 24. Specifically, one electrode 28 of the sheet heating element 24 is electrically connected to the positive terminal of a power source P, one end of the wire 30 is connected to the other electrode 28 of the sheet heating element 24, and the other end of the wire 30 is electrically connected to the negative terminal of the power source P. When the power source P is turned on, electricity is applied to the multiple sheet heating elements 24 through the wire 30.

[0041] In the vehicle seat 10 having the above configuration, a heater device 20 is disposed on the seat cushion 14. The heater device 20 includes a sheet heating element 24 having a heat generating layer in which carbon nanotubes are evenly disposed, and a conductive wire 30 having a zigzag fold portion 32 that is insulated from the sheet heating element 24 and is arranged to overlap the sheet heating element 24 in a zigzag fold state, and electrically connected in series to the sheet heating element 24. In the heater device 20, electricity is passed through the sheet heating element 24 through the wire 30. When the heat generating layer of the sheet heating element 24 is damaged by a blade or the like, the zigzag fold portion 32 of the wire 30 is cut by the blade or the like, thereby cutting off electricity to the sheet heating element 24. This makes it possible to prevent abnormal heat generation in the sheet heating element 24 with a simple configuration, and ensure safety.

[0042] Furthermore, in this heater device 20, the multiple sheet heating elements 24 are connected to each other in series, parallel, or series-parallel, and the multiple zigzag portions 32 of the wire 30 are arranged to overlap the multiple sheet heating elements 24. As a result, if any of the multiple sheet heating elements 24 is damaged, the power supply to that sheet heating element 24 can be cut off, preventing abnormal heat generation.

[0043] In addition, in this heater device 20, when a cut C1 is made in a direction intersecting the direction of the current flowing through the sheet heating element 24 (see arrow I in FIG. 5) in the sheet heating element 24 having a heat generating layer in which the carbon material is evenly distributed, the sheet heating element 24 is more likely to generate more heat than when a cut C2 is made in a direction along the current direction I. The zigzag bend portion 32 of the wire 30 overlapping the sheet heating element 24 extends along the current direction I and has a plurality of extension portions 32B connected to each other via the zigzag bend portion 32A. Therefore, when a cut C1 that is likely to increase the heat generated by the sheet heating element 24 is made as described above, any of the plurality of extension portions 32B is more likely to be cut, and the current to the sheet heating element 24 is more likely to be cut off. This makes it possible to further ensure safety.

[0044] In other words, as in the comparative example shown in Figure 6, when the zigzag portion 32 of the wire 30 has multiple extension portions 32C extending along a direction intersecting the current direction I, when a cut C1 occurs that is likely to increase heat generation in the planar heating element 24, it becomes difficult for any of the multiple extension portions 32C to be cut, making it difficult to cut off the flow of electricity to the planar heating element 24, but this can be avoided in this embodiment.

[0045] In the above embodiment, the wire 30 having the multiple zigzag folds 32 is connected in series to the multiple sheet heating elements 24 connected in series, parallel, or series-parallel, but this is not limiting, and the multiple sheet heating elements 24 connected in parallel may be individually connected in series to each of the multiple sheet heating elements 24. In this case, if any of the multiple sheet heating elements 24 is damaged, the zigzag folds 32 overlapping that sheet heating element 24 can be cut off, thereby cutting off the flow of electricity to only that sheet heating element 24, and allowing the flow of electricity to the other sheet heating elements 24 to continue.

[0046] (Various variations) Next, various modifications of the above embodiment will be described. Note that the same reference numerals as in the above embodiment are used for configurations and operations that are basically the same as those in the above embodiment, and descriptions thereof will be omitted.

[0047] In the example shown in FIG. 7 and FIG. 8A, the heater device 20 includes a fuse 34. The fuse 34 is connected between the wire 30 and the power source P, and is connected in series to the wire 30. In this example, when the heat generating layer of the sheet heating element 24 is damaged by a blade or the like, if the zigzag portion 32 of the wire 30 is not cut by the blade or the like, the temperature of the sheet heating element 24 increases, causing the temperature of the wire 30 to rise, and the resistance value of the wire 30 decreases, thereby increasing the current flowing through the wire 30. As a result, the fuse 34 electrically connected in series to the wire 30 is cut off, cutting off the current to the sheet heating element 24. As a result, even if the wire 30 is not cut, abnormal heat generation of the sheet heating element 24 can be prevented with a simple configuration, and safety can be ensured.

[0048] In the example shown in FIG. 8B, the heater device 20 includes a temperature fuse (or thermostat) 36. The temperature fuse (or thermostat) 36 is connected between the wire 30 and the power source P, and is connected in series to the wire 30. This wire 30 has thermal conductivity. In this example, when the heat generating layer of the sheet heating element 24 is damaged by a blade or the like, if the zigzag portion 32 of the wire 30 is not cut by the blade or the like, the temperature of the sheet heating element 24 increases, causing the temperature of the thermally conductive wire 30 to increase. As a result, the temperature fuse (or thermostat) 36 connected to the wire 30 is cut by the heat transmitted from the wire 30, and the current to the sheet heating element 24 is cut off. This makes it possible to prevent abnormal heating of the sheet heating element 24 with a simple configuration, and ensure safety, even if the wire 30 is not cut.

[0049] In the example shown in Fig. 9, the zigzag bends 32 of the wire 30 overlapping the sheet heating element 24 extend in a creeping direction along the surface of the sheet heating element 24 (here, the opposing direction of the pair of electrodes 28), and have a plurality of extending portions 32D connected to each other via zigzag bent portions 32A, and each extending portion 32D is bent in a zigzag shape. The zigzag width and zigzag fold pitch of the extending portions 32D are set in consideration of the magnitude of damage caused by a blade or the like piercing the heat generating layer of the sheet heating element 24. As a result, when the sheet heating element 24 is damaged by a blade or the like, one of the extending portions 32D is easily cut off, and the current to the sheet heating element 24 is easily cut off, so that safety can be further ensured.

[0050] 10, the heater device 20 has a relay 38 which is a current amplifying means, and is configured so that the current amplified by the relay 38 flows to the sheet heating element 24, while the current that is not amplified by the relay 38 flows to the wire 30. This allows the sheet heating element 24 to be heated by a large current that cannot be passed through the wire 30. The amplifying means is not limited to the relay 38, and may be a transistor or the like.

[0051] 11, the heater device 20 has an ECU (Electronic Control Unit) 40 which is a control device, and is configured so that the current flowing through the wire 30 and the current flowing through the sheet heating element 24 are input to the ECU 40. The ECU 40 detects the electrical resistance value of the wire 30 based on the current flowing through the wire 30, and controls the current flowing through the sheet heating element 24, etc. based on the detection result. This allows the current flowing through the sheet heating element 24, etc. to be controlled with high precision.

[0052] In the example shown in Figs. 12 to 17, the first and second zigzag folds 321 and 322 of the zigzag folds 32 of the wire 30 are overlapped on the sheet heating element 24. The first and second zigzag folds 321 and 322 are sewn into base materials 42 and 44 that are separate from the sheet heating element 24 and are arranged by means of adhesion, adhesion, coating, printing, or the like. The first zigzag folds 321 extend along the direction I of current flowing through the sheet heating element by energization, and have a plurality of first extensions 32B connected to each other via the zigzag bent portions 32A. The second zigzag folds 322 extend along a direction intersecting the direction I of the current, and have a plurality of second extensions 32C connected to each other via the zigzag bent portions 32A. The first zigzag fold portion 321 and the second zigzag fold portion 322 are insulated from each other and arranged to overlap in the direction perpendicular to the surface of the sheet heating element 24. An insulating layer (not shown) is interposed between the first zigzag fold portion 321 and the second zigzag fold portion 322 and between the second zigzag fold portion 322 and the sheet heating element 24.

[0053] The first zigzag fold portion 321 and the second zigzag fold portion 322 may be connected in series via wiring 46 as shown in Fig. 16, or may be separate circuits as shown in Fig. 17, but are connected in series to the sheet heating element 24. When viewed from a direction perpendicular to the surface of this sheet heating element 24, the first extension portions 32B and the second extension portions 32C form a plurality of closed figures (here, a lattice-like figure). This makes it easier for any of the first extension portions 32B and the second extension portions 32C to be cut when the sheet heating element 24 is damaged by a blade or the like, and makes it easier to cut off the current to the sheet heating element.

[0054] 18, first and second fold portions 321 and 322 may be attached to the same base material 48, and first and second fold portions 321 and 322 may be overlapped by folding the base material 48 at fold line L. In that case, a sheet-like insulating layer 50 is sandwiched between first and second fold portions 321 and 322.

[0055] In the example shown in FIG. 19, the wire 30' arranged with the zigzag fold 32 (overlapped portion) overlapping the sheet heating element 24 has thermal conductivity and is not electrically connected to the sheet heating element 24. In this example, a temperature fuse (or thermostat) 36 electrically connected in series to the sheet heating element 24 and the power source P is provided, and a part of the wire 30' is arranged close to the temperature fuse (or thermostat) 36. In this example, when the heat generating layer 26 of the sheet heating element 24 is damaged by a knife or the like, the temperature of the sheet heating element 24 rises, and the temperature of the wire 30' rises. As a result, the fuse (or thermostat) 36 arranged close to a part of the wire 30' is cut by the heat transmitted from the wire 30', and the current to the sheet heating element 24 is cut off. This makes it possible to prevent abnormal heat generation of the sheet heating element 24 with a simple configuration.

[0056] Although the present invention has been described above by way of the embodiment and modified examples, the present invention can be modified in various ways without departing from the spirit of the present invention. Furthermore, it goes without saying that the scope of the present invention is not limited to the above embodiment and modified examples. [Explanation of symbols]

[0057] 10 Vehicle seats 12 Seat body 14 Seat cushion 16 Seat back 20 Heater device 24 Planar heating element 30 wire rod 32 Folds (overlapped section) 321 First Fold 322 The second fold 32A Bending section 32B Extension 32C extension 32D extension 34 Fuse 36 Thermal fuse or thermostat

Claims

1. a sheet heating element having a heating layer in which a carbon material is evenly distributed; a conductive wire having an overlapping portion disposed to overlap the sheet heating element and electrically connected to the sheet heating element; wherein when the wire is cut, power to the sheet heating element is cut off.

2. The heater device according to claim 1 , further comprising a fuse electrically connected in series with the wire.

3. The heater device according to claim 1 , wherein the wire has thermal conductivity and includes a temperature fuse or a thermostat connected to the wire.

4. A plurality of sheet heating elements are provided, 4. The heater device according to claim 1, wherein the wire has a plurality of overlapping portions arranged to overlap the plurality of sheet heating elements, respectively.

5. The heater device according to any one of claims 1 to 3, wherein the overlapping portion is a zigzag fold portion.

6. The heater device according to claim 5 , wherein the zigzag fold portion extends in a direction in which a current flows through the sheet heating element when energized, and includes a plurality of extending portions connected to each other via the zigzag fold portions.

7. The heater device according to claim 5, wherein the zigzag fold portion extends in a surface direction along the surface of the sheet heating element, has a plurality of extending portions connected to each other via the zigzag fold bends, and each of the extending portions is bent in a zigzag shape.

8. The zigzag fold portion is A first zigzag fold portion extending along a first direction along a surface of the sheet heating element and having a plurality of first extending portions connected to each other via the zigzag folds; A second zigzag fold portion extending along a surface of the sheet heating element and along a second direction intersecting the first direction and having a plurality of second extending portions connected to each other via the zigzag folds; Equipped with The heater device according to claim 5 , wherein the first zigzag fold portion and the second zigzag fold portion are insulated from each other and are arranged to overlap in a direction perpendicular to a surface of the planar heating element.

9. a sheet heating element having a heating layer in which a carbon material is evenly distributed; a wire having thermal conductivity and an overlapping portion disposed on the sheet heating element; a temperature fuse or a thermostat electrically connected in series with the sheet heating element and disposed adjacent to a portion of the wire; A heater device comprising:

10. a seat body having a seat cushion on which a vehicle occupant sits and a seat back supporting the back of the occupant; The heater device according to claim 1 or claim 9, wherein the sheet heating element is disposed on the seat main body; A vehicle seat comprising:

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