JP6865945B2 - heater - Google Patents

Description

The present invention relates to a heater using a PTC (Positive Temperature Cofficient) thermistor element.

Conventionally, a heater using a PTC thermistor element has been known. The PTC thermistor element acts as a heating element because it has a unique resistance value at low temperatures, and has a self-temperature control function in which the resistance value rapidly increases above the Curie temperature to cut off energization. A highly safe heater can be realized. In recent years, there has been an increase in demand for hot air such as hot air heaters and bathroom heaters / dryers.

The PTC heater for warm air has, for example, a structure in which a PTC thermistor element in which a pair of electrodes are arranged on a heat generating element made of semiconductor ceramic is housed in a case. Further, from the viewpoint of safety, it is preferable that the PTC heater for warm air is an insulating type in which an insulating material such as a polyimide film or an alumina substrate is arranged between the PTC thermistor element and the case (for example, Patent Documents). 1). First, it is preferable that the insulator has excellent thermal conductivity in order to efficiently transfer heat from the PTC thermistor element to the case. Secondly, in the manufacturing process, the PTC thermistor element is put in the case and the case is crimped, so that it needs to withstand mechanical impact. Thirdly, since the thickness of the PTC thermistor element varies in quality, it is preferable that the PTC thermistor element has excellent flexibility and cushioning property capable of absorbing the thickness variation.

Regarding these characteristics, when examining the polyimide film and the alumina substrate, the polyimide film is excellent in flexibility and mechanical impact (cracking), but has low thermal conductivity and insufficient cushioning property (rubber elasticity). There was a problem. On the other hand, although the alumina substrate is excellent in thermal conductivity, it lacks flexibility and cushioning property (rubber elasticity), and has a problem that it is also vulnerable to mechanical impact (cracking). Therefore, it has been required to study a new insulator having these characteristics in a well-balanced manner.

Japanese Unexamined Patent Publication No. 2010-34111

The present invention has been made based on such a problem, and an object of the present invention is to provide a heater which is excellent in thermal conductivity, resistant to mechanical shock, and can easily absorb thickness variation.

The heater of the present invention includes a PTC thermistor element in which a pair of electrode layers are arranged on a heat generating element, and a pair of electrode plates arranged so as to face the PTC thermistor element in a direction facing the pair of electrode layers. It has a configuration in which a case for accommodating a PTC thermistor element and a pair of electrode plates is arranged inside, and a silicon layer is provided on both sides of a glass cloth layer, which is arranged between the PTC thermistor element and a pair of electrode plates and the case. It is equipped with an insulating sheet.

According to the present invention, since the insulating sheet has a structure in which silicon layers are provided on both sides of the glass cloth layer, the insulating sheet can obtain excellent thermal conductivity as compared with the polyimide film in addition to excellent insulating performance. In addition, it is possible to obtain properties such as flexibility, cushioning property (rubber elasticity), and resistance to mechanical impact. Therefore, by using this insulating sheet, it is possible to efficiently transfer the heat generated by the PTC thermistor element to the case while ensuring the insulation between each PTC thermistor element and the pair of electrode plates and the case. Therefore, even if the number of PTC thermistor elements is small, a large amount of power consumption can be obtained and space can be saved. Further, even if the case is crimped, the occurrence of cracks and the like can be suppressed, and the variation in the thickness of the PTC thermistor element can be absorbed.

Further, if the warp and weft of the glass cloth layer are arranged so as to intersect with each other in the opposite direction of the opening of the case, the pulling force when the case is crimped is extended even if it works, so that a break may occur. It can be suppressed. Therefore, the yield can be improved.

It is a figure which shows the appearance structure of the heater which concerns on one Embodiment of this invention. It is a figure which shows the cross-sectional structure along the line II-II shown in FIG. It is a figure which shows the cross-sectional structure along the line III-III shown in FIG. It is a figure which shows the structure of an insulating sheet.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of the heater 1 according to the embodiment of the present invention. FIG. 2 shows a cross-sectional configuration along the line II-II shown in FIG. FIG. 3 shows a cross-sectional configuration along the line III-III shown in FIG. The heater 1 is preferably used for warm air, for example, and includes a heater unit 10 in which a plurality of PTC thermistor elements 11 are housed inside a case 12.

Each PTC thermistor element 11 has a positive temperature characteristic, and the resistance rapidly increases above the Curie temperature to limit the temperature rise beyond that. Each PTC thermistor element 11 has, for example, a configuration in which a pair of electrode layers 11B are arranged on a heat generating element 11A. The heat generating element 11A is composed of, for example, a semiconductor ceramic plate made of a sintered body containing a _{barium titanate (BaTIO 3) -based compound as a main component.} The pair of electrode layers 11B are made of, for example, a metal such as silver or aluminum, and are provided on opposite surfaces of the heat generating element 11A in the thickness direction.

Each PTC thermistor element 11 is provided with a pair of electrode plates 13 so as to face each other in the opposite direction of the pair of electrode layers 11B, for example. Each PTC thermistor element 11 is sandwiched between a pair of electrode plates 13 and arranged side by side, and is connected in parallel to the pair of electrode plates 13. The pair of electrode plates 13 are made of, for example, a metal such as stainless steel, and are in contact with the pair of electrode layers 11B, respectively. For example, a pair of electric wires 14 are connected to the pair of electrode plates 13. As a result, each electric wire 14 is electrically connected to the pair of electrode layers 11B of the PTC thermistor element 11 via the pair of electrode plates 13. Each electric wire 14 has, for example, a structure in which a conducting wire is covered with a coating material.

The case 12 is made of a material having high thermal conductivity and ease of processing, such as aluminum. The case 12 is, for example, a hollow body having openings 12A and 12B at both ends, and specifically, has a square tubular shape. At least one of the openings 12A and 12B provided at both ends of the case 12 is used to pull out the electric wire 14. In this embodiment, one of the wires 14 is drawn out from the opening 12A, while the wire 1 4 is pulled out from the opening 12B. For example, closing members 15A and 15B are arranged in the openings 12A and 12B, respectively, and are closed.

An insulating sheet 16 made of, for example, an insulating material is arranged between each PTC thermistor element 11 and a pair of electrode plates 13 and a case 12. Specifically, for example, the insulating sheet 16 covers the periphery of each PTC thermistor element 11 and the pair of electrode plates 13 on the side facing the case 12. The case 12 is in contact with the PTC thermistor element 11 via the electrode plate 13 and the insulating sheet 16 in the stacking direction of the PTC thermistor element 11 and the electrode plate 13 by being crimped, for example. This is to efficiently transfer the heat generated in the PTC thermistor element 11 to the case 12.

As shown in FIG. 4, for example, the insulating sheet 16 has a structure in which silicon layers 16B are provided on both sides of the glass cloth layer 16A. In addition to being excellent in insulating performance, the insulating sheet 16 is superior in thermal conductivity to polyimide film, has flexibility and cushioning properties (rubber elasticity), and is also resistant to mechanical impact. It has the characteristic of. Therefore, by using this insulating sheet 16, it is possible to efficiently transfer the heat generated by the PTC thermistor element 11 to the case 12 while ensuring the insulation between each PTC thermistor element 11 and the pair of electrode plates 13 and the case 12. Further, even if the case 12 is crimped, the occurrence of cracks and the like can be suppressed, and the variation in the thickness of the PTC thermistor element 11 can be absorbed.

The insulating sheet 16 is preferably arranged so that the extending directions of the warp threads and the weft threads forming the glass cloth layer 16A intersect with each other in the opposite directions of the openings 12A and 12B of the case 12. If either the warp or the weft is arranged so as to be parallel to the opposite directions of the openings 12A and 12B of the case 12, when the case 12 is crimped, a pulling force acts and the case 12 is locally cut. On the other hand, if they are arranged so as to intersect with each other, they will be stretched even if they are pulled, so that the occurrence of cutting can be suppressed.

The inclination angle of the warp or weft with respect to the facing direction of the openings 12A and 12B of the case 12 is preferably 1 ° or more and 45 ° or less, and more preferably 5 ° or more and 45 ° or less. The state of the insulating sheet 16 after the case 12 was crimped was observed by changing the inclination angle of the warp or weft of the insulating sheet 16 with respect to the opposite directions of the openings 12A and 12B of the case 12. Specifically, a pair of electrode plates 13 are arranged on the PTC thermistor element 11, covered with an insulating sheet 16 and stored inside the case 12, the case 12 is crimped, and then taken out from the case 12 for insulation. The state of the sheet 16 was observed. The inclination angle of the warp or weft with respect to the facing direction of the openings 12A and 12B of the case 12 was changed to 0 °, 5 °, or 45 °.

As a result, when the inclination angle of the warp or weft with respect to the facing direction of the openings 12A and 12B of the case 12 is 0 °, that is, when the warp or weft is parallel to the facing direction of the openings 12A and 12B of the case 12, The defective rate at which the insulating sheet 16 was cut was about 14%. On the other hand, when the inclination angle of the warp or weft with respect to the opposite directions of the openings 12A and 12B of the case 12 is 5 ° and 45 °, the insulating sheet 16 is defective. The rate was 0%. That is, it can be seen that the occurrence rate of defects can be significantly reduced if the warp threads and weft threads of the glass cloth layer 16A intersect with each other in the opposite directions of the openings 12A and 12B of the case 12.

Further, on the outside of the case 12, for example, heat sinks 17 are provided on a pair of side portions in contact with the PTC thermistor element 11 via the insulating sheet 16 and the electrode plate 13. In FIG. 3, the display of the heat sink 17 is omitted. The heat sink 17 has, for example, a bellows portion 17A in which a plate material is bent into a shape in which peaks and valleys are repeated, and a plate-shaped portion 17B provided on the opposite side of the bellows portion 17A from the case 12. .. The heat sink 17 is made of a material having high thermal conductivity such as aluminum. For example, resin brackets 18 are arranged at both ends of the case 12.

The heater 1 is manufactured, for example, as follows. First, for example, the PTC thermistor element 11 is manufactured by disposing a pair of electrode layers 11B on the heat generating element 11A. Next, for example, a pair of electrode plates 13 are arranged on the PTC thermistor element 11, and a pair of electric wires 14 are connected to the pair of electrode plates 13, respectively. Subsequently, for example, a PTC thermistor element 11 in which a pair of electrode plates 13 are arranged is covered with an insulating sheet 16 and stored inside the case 12, and the case 12 is crimped. As a result, the PTC thermistor element 11 and the case 12 are brought into contact with each other via the electrode plate 13 and the insulating sheet 16 in the stacking direction of the PTC thermistor element 11 and the pair of electrode plates 13. After that, the electric wires 14 are pulled out from the openings 12A and 12B of the case 12, the closing members 15A and 15B are arranged in the openings 12A and 12B, and the heat sink 17 is arranged on the outside of the case 12.

In the present embodiment, since the insulating sheet 16 having silicon layers provided on both sides of the glass cloth layer is used, the insulating sheet 16 has flexibility and cushioning property (rubber elasticity), and is resistant to mechanical impact. It has become. Therefore, even if the case 12 is crimped, the occurrence of cracks and the like can be suppressed, and the variation in the thickness of the PTC thermistor element 11 can be absorbed. Further, if the warp and weft of the glass cloth layer 16A are arranged so as to intersect the opposite directions of the openings 12A and 12B of the case 12, the pulling force when the case 12 is crimped is extended. It is possible to suppress the occurrence of cutting.

Further, the heater 1 operates as follows. In this heater 1, for example, when the PTC thermistor element 11 is energized via a pair of electric wires 14, the heat generating element 11A generates heat. The heat generated from the heat generating element 11A is transmitted to the heat sink 17 via the electrode layer 11B, the electrode plate 13, the insulating sheet 16, and the case 12. In the present embodiment, since the insulating sheet 16 in which the silicon layers are provided on both sides of the glass cloth layer is used, the heat conductivity of the insulating sheet 16 is excellent. Therefore, the heat generated by the PTC thermistor element 11 can be efficiently transferred to the case 12, and even if the number of PTC thermistor elements 11 is small, a large amount of power consumption can be obtained. Therefore, space saving can be achieved.

As described above, according to the present embodiment, since the insulating sheet 16 is configured to have the silicon layers 16B provided on both sides of the glass cloth layer 16A, the insulating sheet 16 has better insulating performance than the polyimide film. Excellent thermal conductivity can be obtained, and properties such as flexibility, cushioning property (rubber elasticity), and resistance to mechanical impact can also be obtained. Therefore, by using this insulating sheet 16, it is possible to efficiently transfer the heat generated by the PTC thermistor element 11 to the case 12 while ensuring the insulation between each PTC thermistor element 11 and the pair of electrode plates 13 and the case 12. it can. Therefore, even if the number of PTC thermistor elements 11 is small, a large amount of power consumption can be obtained and space can be saved. Further, even if the case 12 is crimped, the occurrence of cracks and the like can be suppressed, and the variation in the thickness of the PTC thermistor element 11 can be absorbed.

Further, if the warp and weft of the glass cloth layer 16A are arranged so as to intersect the opposite directions of the openings 12A and 12B of the case 12, the pulling force when the case 12 is crimped is extended. Therefore, the occurrence of cutting can be suppressed. Therefore, the yield can be improved.

Although the present invention has been described above with reference to embodiments and examples, the present invention is not limited to the above embodiments and examples, and can be variously modified. For example, in the above-described embodiment, each component has been specifically described, but other components may be provided. Further, it may not have all the components, and may further include other components. Further, in the above embodiment, the case where one heater unit 10 is provided has been described, but a plurality of heater units 10 may be connected to form the heater 1.

It can be used for a heater using a PTC thermistor element.

1 ... Heater, 10 ... Heater unit, 11 ... PTC thermistor element, 11A ... Heat generation element, 11B ... Electrode layer, 12 ... Case, 12A, 12B ... Opening, 13 ... Electrode plate, 14 ... Electric wire, 15A, 15B ... Closing member , 16 ... Insulation sheet, 16A ... Glass cloth layer, 16B ... Silicon layer, 17 ... Heat sink, 17A ... Bellows part, 17B ... Plate-shaped part, 18 ... Bracket

Claims (2)

A PTC thermistor element in which a pair of electrode layers are arranged on the heat generating element, and
A pair of electrode plates arranged so as to face the PTC thermistor element in the opposite direction of the pair of electrode layers, and a pair of electrode plates.
A case for accommodating the PTC thermistor element and the pair of electrode plates inside,
The PTC thermistor element and the pair of electrode plates are provided with an insulating sheet disposed between the case and having a structure in which silicon layers are provided on both sides of a glass cloth layer.
By crimping, the case is in contact with the PTC thermistor element via the electrode plate and the insulating sheet in the stacking direction of the PTC thermistor element and the electrode plate.
The case is a hollow body having openings at both ends.
The insulating sheet is arranged so that the extending directions of the warp threads and the weft threads forming the glass cloth layer intersect with each other in the opposite direction of the opening of the case.
A heater characterized in that the inclination angle of the warp or weft of the glass cloth layer with respect to the direction opposite to the opening of the case is 5 ° or more and 45 ° or less. The heater according to claim 1, wherein the heater is for warm air.

Images