JP6477394B2 - Electric heater - Google Patents

Description

    The present invention relates to an electric heater composed of a plurality of film-like heaters.

  An electric heater is disclosed that can heat a fluid passing through a honeycomb by applying a conductive heat generating paint to the surface of a carrier formed in a honeycomb shape to form a heat generating layer (for example, Patent Document 1). .

JP 2006-35939 A

  Instead of integrally forming the honeycomb structure or the like, it may be possible to realize a passage structure such as a honeycomb using a film heater. In that case, a plurality of film-like heaters are arranged facing each other, and a part of the facing film-like heaters are joined together to form a cavity that becomes a passage between two adjacent joints. Become.

  Then, two film-like heaters will overlap at the joint, and the amount of heat generated at that portion will be greater than at the other portions. For this reason, the temperature of a junction part becomes higher than another part, and corresponding heat resistance is also requested | required also for the constituent material (for example, electrically insulating film) of a film-like heater.

  In view of the above points, the present invention provides an electric device capable of suppressing an increase in heat resistance required for the constituent material of the film heater in manufacturing an electric heater having a passage structure such as a honeycomb using the film heater. An object is to provide a heater.

  The invention according to claim 1 for achieving the above object includes a plurality of film heaters (1, 33, 47, 61, 65) arranged in a posture in which adjacent ones face each other, The plurality of film heaters include a plurality of joints (17, 62, 66) in which parts of two film heaters are joined to each other, and a part of one film heater is another film. A plurality of single portions (19) disposed away from the heater, and the plurality of film-like heaters are configured such that each of the plurality of joint portions and each of the plurality of single portions are alternately disposed. Thus, a plurality of passage holes (18, 63, 67) through which the fluid to be heated passes are formed, and each of the plurality of film-like heaters is an electrically insulating insulating film ( 3) A pair of spaced apart on top A plurality of joints, each including an electrode (5a, 5b, 35a, 35b, 49a, 49b) and a heat generating layer (13, 43, 53) laminated on the insulating film and conducting between the pair of electrodes. At least one of the two film-like heaters constituting each of the parts has an energization suppressing portion (15, 37, 45) at the joint portion, and the pair of electrodes in the energization suppressing portion The electrical resistance per unit length in the longitudinal direction of the one film heater is between the pair of electrodes in the single part belonging to the at least one film heater among the plurality of single parts. The electric heater is higher than the electric resistance per unit length in the longitudinal direction.

  In this way, in the energization suppression unit, the amount of heat generated is also suppressed by suppressing the energization amount between the pair of electrodes, so that the temperature of the bonding portion can be suppressed from becoming higher than the other portions. . Therefore, it is possible to suppress an increase in heat resistance required for the constituent material of the film heater.

It is a top view of the film-like heater of a 1st embodiment. It is a top view which shows a part of honeycomb structure of the electric heater of 1st Embodiment. It is a perspective view showing typically the honeycomb structure of the electric heater of a 1st embodiment. It is a top view of the electric heater of a 1st embodiment. It is a figure which shows arrangement | positioning of the film-like heater 1 before adhesion | attachment. It is a figure which shows the film-like heater 33 of 2nd Embodiment. It is a figure which shows the film-like heater 47 of 3rd Embodiment. It is a figure which shows the film-like heater 48 of 3rd Embodiment. It is a figure which shows the film-like heater 47 of a modification. It is explanatory drawing of the modification of a passage hole. It is explanatory drawing of the other modification of a passage hole.

Hereinafter, an embodiment in which the electric heater of the present invention is embodied as a heater of a vehicle air conditioner will be described with reference to the drawings.
(First embodiment)
First, the first embodiment will be described. In the present embodiment, as shown in FIG. 1, the film heater 1 includes an insulating film 3, an electrode 5 a, an electrode 5 b, and a heat generating layer 13. The insulating film 3 is an electrically insulating and rectangular film such as polyethylene, polyethylene terephthalate, and polyvinyl chloride. The electrodes 5a and 5b are arranged apart from each other in parallel on one side of the insulating film 3.

  The electrodes 5a and 5b are provided with a plurality of concave portions 7a and 7b having concave portions facing the counterpart electrode. And between the adjacent recessed part 7a and the recessed part 7a becomes the relatively convex convex part 9a, and similarly between the adjacent recessed part 7b and the recessed part 7b becomes the relatively convex convex part 9b.

  The distance D1 between the concave portions 7a and 7b facing each other is twice the distance D2 between the convex portions 9a and 9b facing each other. Further, the length L1 of the concave portions 7a and 7b along the longitudinal direction of the electrodes 5a and 5b and the length L2 of the convex portions 9a and 9b are substantially equal.

  A land 11a for connecting a lead wire or the like by soldering or the like is provided at one end of the electrode 5a (specifically, the left end in FIG. 1). A land 11b for connecting a lead wire or the like by soldering or the like is provided at one end portion (specifically, the right end portion in FIG. 1) opposite to the one end portion of the electrode 5b.

  In this embodiment, the electrodes 5a and 5b are provided on the insulating film 3 by copper plating. However, the electrodes 5a and 5b may be provided by applying a metal foil such as copper or aluminum or applying a metal paste such as silver.

  The heat generating layer 13 is laminated on the insulating film 3 so as to cover the electrodes 5a and 5b. The heat generating layer 13 is generated by applying a conductive heat generating paint (for example, Everiome, Bunny Height: manufactured by Nippon Graphite Industry Co., Ltd.). The conductive heat generating paint corresponds to a conductive heat generating material. The generated heat generating layer is electrically connected to each of the concave portions 7a and 7b and the convex portions 9a and 9b of the electrodes 5a and 5b. For this reason, if a voltage is applied between the electrodes 5a and 5b, the heat generating layer 13 generates heat by energization.

  However, since the distance D1 between the facing concave portions 7a and 7b is larger than the distance D2 between the convex portions 9a and 9b, the electric resistance of the heat generating layer 13 is greater between the concave portions 7a and 7b than between the convex portions 9a and 9b. Large (doubled by design). Accordingly, the amount of heat generated when the heat generating layer 13 is energized is smaller between the concave portions 7a and 7b than between the convex portions 9a and 9b. That is, the region between the concavities 7 a and 7 b facing each other is the energization suppressing unit 15.

  As shown in FIG. 4, the electric heater 27 according to the present embodiment has a plurality of such film-like heaters 1. The procedure for creating the electric heater 27 from a plurality of film-like heaters 1 is as follows.

  First, as shown in FIG. 6, a plurality of film heaters 1 are stacked in parallel and spaced apart from each other, and an adhesive 70 is applied to each of the plurality of film heaters 1. By doing in this way, the several film-like heater 1 is arrange | positioned with the attitude | position with which adjacent one side faces each other. A plurality of application positions of the adhesive 70 in each film heater 1 are scattered at equal intervals in the longitudinal direction on the same side of the film heater 1.

  Further, as shown in FIG. 5, the application positions of the adhesive 70 in the longitudinal direction of each film heater 1 are staggered between two adjacent film heaters 1. That is, the application position of the adhesive 70 in the longitudinal direction in one film heater 1 is a position equidistant from the two adhesives 70 adjacent in the longitudinal direction in the adjacent film heater 1.

  Next, the plurality of film-like heaters 1 stacked apart are brought into contact with each other. Thereby, two adjacent film-like heaters 1 are joined via the adhesive 70 at the application position of the adhesive 70.

  Next, among the plurality of film-like heaters 1, the film-like heater 1 at one end in the laminating direction is pulled toward the one side in the laminating direction, and the film-like heater 1 at the other end in the laminating direction is taken as the other in the laminating direction. Pull to the side. As a result, the plurality of film-like heaters 1 have a honeycomb shape as shown in FIGS. Even if the film heater 1 is light and has a low strength, the strength of the plurality of film heaters 1 as a whole is improved by forming a honeycomb shape. Next, the plurality of film-like heaters 1 having a honeycomb shape are fixed inside the frame body 21.

  In the electric heater 27 manufactured as described above, each of the plurality of portions joined by the adhesive 70 becomes the joining portion 17. In each of these joint portions 17, a part of the two film heaters 1 is joined. That is, at each joint portion 17, the surface corresponding to the top of the wave in one film heater 1 and the surface corresponding to the valley of the wave in the other film heater 1 are bonded. Each of the joint portions 17 includes an energization suppressing portion 15 of each of the two film heaters 1 constituting the joint portion 17.

  Moreover, the electric heater 27 manufactured in this way has a plurality of single portions 19 in which a part of one film heater 1 is arranged apart from other film heaters. Each of the plurality of single portions 19 does not include the energization suppressing portion 15.

  As shown in FIGS. 2 and 3, the plurality of film-like heaters 1 constituting the electric heater 27 are formed by alternately arranging each of the plurality of joint portions 17 and each of the plurality of single portions 19. In addition, it is formed in a shape surrounding the plurality of passage holes 18 through which the fluid to be heated passes. These passage holes 18 have a hexagonal column shape. When the fluid (air in this embodiment) passes through these passage holes 18 in a direction perpendicular to the paper surface in FIG. 2, the fluid is heated.

  In the two film-like heaters 1 to be joined, since one insulating film 3 is in contact with the other heat generating layer 13 and the electrodes 5a and 5b, the heat generating layers 13 and the electrodes 5a and 5b are in contact with each other. There is no short circuit between them.

  As shown in FIG. 4, the film-like heater 1 assembled in the honeycomb structure is assembled inside a plastic frame body 21. A flange portion 23 for attachment is provided on a side surface of the frame body 21, and a + terminal 25 a and a − terminal 25 b protrude from the flange portion 23.

  One of the lands 11a and 11b of each film heater 1 assembled inside the frame 21 is connected to the + terminal 25a (for example, the land 11a), and the other (for example, the land 11b) is connected to the + terminal 25b. . Thereby, if each of the + terminal 25a and the −terminal 25b is connected to a power source and energized, each film heater 1 can generate heat.

  An electric heater 27 having a structure in which a honeycomb structure made of a film-like heater 1 is assembled inside a frame body 21 is attached to an air conditioning duct (not shown) of a vehicle via a flange portion 23, and serves as a heater for an air conditioning apparatus for a vehicle. used. Alternatively, the electric heater 27 is attached via the flange portion 23 in the air conditioning casing of the vehicle, more specifically, on the downstream side of the air flow of the heater core. Here, the air conditioning casing introduces air and heats or cools it, and blows out the air heated or cooled as described above into the vehicle compartment via the air conditioning duct. The heater core heats the air flowing in the air conditioning casing using the heat of the engine cooling water.

  As described above, the electric heater 27 according to the present embodiment is formed between two adjacent joints 17 and 17 by joining a part of the film heater 1 facing each other at the joint 17. A passage hole 18 that is a hexagonal column-shaped cavity is provided, and heat is generated by energizing the heat generating layer 13 through the pair of electrodes 5a and 5b of each film heater 1, and the fluid (air) in the passage hole 18 is heated. it can.

  Moreover, in the junction part 17, the electricity supply suppression part 15 whose electrical resistance between the electrodes 5a and 5b is higher than the electrical resistance between the electrodes 5a and 5b located in the passage hole 18 part is provided.

  More specifically, in each film heater 1, the electrical resistance per unit length in the longitudinal direction of the film heater 1 between the pair of electrodes 5 a and 5 b in the energization suppressing unit 15 is a plurality of single parts. The electrical resistance per unit length in the longitudinal direction between the pair of electrodes 5a and 5b in each of 19 is higher. The electrical resistance per unit length in the longitudinal direction of the film heater 1 is proportional to the distance between the electrodes 5a and 5b, and is proportional to the electrical resistivity of the conductive heat-generating paint constituting the heat-generating layer 13, and the heat-generating layer. It is inversely proportional to the thickness of 13. In the present embodiment, the thickness and the electrical resistivity of the heat generating layer 13 are the same at any position of any film heater 1.

In the energization suppressing unit 15, the amount of heat generated is also suppressed by suppressing the energization amount between the pair of electrodes 5 a and 5 b, so that the temperature of the joint portion 17 can be suppressed from becoming higher than the temperature of the single portion 19. Therefore, it is possible to suppress the heat resistance required for the constituent material of the film heater 1, particularly the insulating film 3, and to suppress the upgrading of the constituent material of the film heater 1.
(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. The electric heater 27 of the present embodiment is obtained by replacing the plurality of film heaters 1 with a plurality of film heaters 33 with respect to the electric heater 27 of the first embodiment. Moreover, each film heater 33 of this embodiment is obtained by replacing the electrodes 5a and 5b with the electrodes 35a and 35b, respectively, with respect to the film heater 1 of the first embodiment. Other configurations are the same as those of the first embodiment.

  In the first embodiment, the energization suppressing portion 37 is formed by providing the recesses 7a and 7b in the electrodes 5a and 5b. However, in the present embodiment, as shown in FIG. 6, the widths of the electrodes 35a and 35b are constant. As the position of the electrodes 35a and 35b in the short direction of the film heater 1 is changed, the energization suppressing portion 37 where the distance between the electrodes 35a and 35b is D1 and the distance between the electrodes 35a and 35b is D1. A portion that becomes shorter D2 is formed.

  Therefore, also in the present embodiment, in each film heater 33, the electrical resistance per unit length in the longitudinal direction of the film heater 33 between the pair of electrodes 35a and 35b in the energization suppressing portion 37 is a plurality of pieces. The electrical resistance per unit length in the longitudinal direction between the pair of electrodes 35a and 35b in each of the single portions 19 is higher.

Also in the present embodiment, as in the first embodiment, the interval D1 is twice the interval D2. In addition, since it is the same as that of 1st Example except the form of electrode 35a, 35b and the electricity supply suppression part 37, illustration and description are abbreviate | omitted. In the second embodiment configured as described above, the same effect as that of the first embodiment can be obtained.
(Third embodiment)
Next, a third embodiment will be described. In the first embodiment and the second embodiment described above, the energization suppressing portions 15 and 37 are formed by increasing the distance between the pair of electrodes 5a, 5b, 35a, and 35b relative to other portions. Yes. On the other hand, in the electric heater 27 of this embodiment, as shown in FIG. However, this energization suppressing part 45 is provided only in one of the two film-like heaters 47 joined.

  Hereinafter, the film heater 1 used for the electric heater 27 of this embodiment will be described. There are two types of film heaters 1 used in this embodiment. The first type is a film heater 47 configured as shown in FIG. 7, and the second type is a film heater 48 configured as shown in FIG.

  The film heater 47 having the configuration shown in FIG. 7 is different from the film heater 1 of the first embodiment in that the electrodes 5a and 5b are replaced with electrodes 49a and 49b, respectively, and the heat generating layer 13 is replaced with a plurality of heat generating layers 43. This is realized.

  Unlike the first and second embodiments, the distance between the electrodes 49 a and 49 b is constant at any position in the longitudinal direction of the film heater 47. Further, unlike the first and second embodiments, a plurality of heat generating layers 43 are scattered at equal intervals in the longitudinal direction of the film heater 47. The material of each heat generating layer 43 is the same as that of the heat generating layer 13 of the first and second embodiments. Therefore, a current flows between the electrodes 49 a and 49 b through the heat generating layers 43. A plurality of regions between the heat generating layer 43 and the heat generating layer 43 adjacent to each other in the longitudinal direction of the film heater 47, that is, a plurality of regions where the heat generating layer 43 does not exist, serves as the energization suppressing unit 45. The heating layer 43 is not laminated on the insulating film 3 in the entire range of the energization suppressing portion 45. Therefore, no current flows between the electrodes 49 a and 49 b in the entire range of the energization suppressing unit 45. Therefore, the electrical resistance between the electrodes 49a and 49b in this portion is infinite.

  Therefore, as a matter of course, also in this embodiment, in each film heater 47, the electrical resistance per unit length in the longitudinal direction of the film heater 47 between the pair of electrodes 49a and 49b in the energization suppressing portion 45 is as follows. The electrical resistance per unit length in the longitudinal direction between the pair of electrodes 49a and 49b in each of the plurality of single portions 19 is higher. Accordingly, the energization suppressing part 45 generates little heat compared to other parts.

  The film heater 48 having the configuration shown in FIG. 9 is realized by replacing the electrodes 5a and 5b with the electrodes 49a and 49b, respectively, with respect to the film heater 1 of the first embodiment. Therefore, the film heater 48 is obtained by replacing the film heater 47 with a plurality of heat generation layers 43 connected to one heat generation layer 13. In the film heater 48, the same amount of current flows from the electrode 49a to the electrode 49b in any part in the longitudinal direction, and the heat generation amount is the same.

  In the present embodiment, the plurality of film heaters 47 and the plurality of film heaters 48 form a honeycomb shape as a whole. This is realized by alternately laminating the film heater 47 and the film heater 48 one by one. However, at that time, each of the joining portions 17 includes one energization suppressing portion 45 of the film heater 47, and the single portion does not include the energization suppressing portion 45 of the film heater 47. 48 is joined.

  As a result, in the joint portion 17 of the present embodiment, a part of the film heater 47 belonging to the joint portion 17 hardly generates heat, and a part of the film heater 48 belonging to the joint portion 17. Generates heat to the same extent as each individual portion 19. Therefore, as a whole, the amount of heat generated in the joint portion 17 and the single portion 19 is approximately equal to the amount of heat generated, and the temperatures of the respective portions of the film heaters 47 and 48 are made uniform.

  Thus, in this embodiment, since the current does not flow between the electrodes 49a and 49b in the energization suppressing unit 45, the same effect as in the first and second embodiments can be obtained. Further, since the distance between the electrodes 49a and 49b may be constant, there is an advantage that the configuration of the electrodes 49a and 49b is not complicated.

(Other embodiments)
In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably. Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible. In each of the above-described embodiments, the elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. In particular, when a plurality of values are exemplified for a certain amount, it is also possible to adopt a value between the plurality of values unless specifically stated otherwise and in principle impossible. . Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like. The present invention also allows the following modifications to the above embodiments. In addition, the following modifications can select application and non-application to the said embodiment each independently. In other words, any combination of the following modifications can be applied to the above-described embodiment.

(Modification 1)
In the third embodiment, the electrical resistance per unit length in the longitudinal direction of the film heater 47 in the energization suppressing unit 45 is infinite, and the current flowing through the energization suppressing unit 45 is zero. However, even if the electrical resistance per unit length in the longitudinal direction of the film heater 47 in the energization suppression unit 45 is not infinite, the electrical resistance per unit length in the longitudinal direction other than the energization suppression unit 45 of the film heater 47 is not limited. It only needs to be smaller than the resistance. Therefore, for example, in the third embodiment, a conductive heat generating paint having a higher electrical resistivity than the conductive heat generating paint constituting the heat generating layer 43 is used for each energization suppressing unit 45, and the conductive heat generating paint forming the heat generating layer 43 is used. The same thickness may be applied.

(Modification 2)
In the above-described third embodiment, the region where the conductive heat-generating paint that becomes the heat generating layer 43 is not laminated is formed as the energization suppressing unit 45, but as shown in FIG. The conductive heat generating paint may be provided in a stripe shape. In this case, the conductive heat generating material forming the heat generating layer 43 is not laminated on the insulating film 3 in a part of the energization suppressing portion 45. Even in this case, in the energization suppressing portion 45, the heat generation layer 53 provided in a stripe shape suppresses the current flowing between the electrodes 49a and 49b, so that the same effect as in the third embodiment can be obtained.
(Modification 3)
In the first embodiment described above, a plurality of film heaters form a honeycomb structure in which the shape of the passage hole 18 is a hexagonal column shape. However, the shape and the like of the passage hole are not limited to this, and can be changed as appropriate.

For example, as shown in FIG. 10, the uneven shape of the film heater 61 is a rectangular wave, and the passage hole 63 formed between the joints 62 is rectangular, or the unevenness of the film heater 65 is shown in FIG. It is also possible to make the passage hole 67 formed between the joint portions 66 into a substantially oval shape with a corrugated shape.
(Modification 4)
In each of the above embodiments, the electrical resistance per unit length in the longitudinal direction of one film heater between a pair of electrodes in each energization suppressing portion is a pair of the single portion in any single portion. It is higher than the electric resistance per unit length in the longitudinal direction of one film heater between the electrodes.

  However, this is not necessarily the case. The electrical resistance per unit length in the longitudinal direction of one film heater between a pair of electrodes in each energization suppressing portion is the at least one film shape among a plurality of single portions constituting the electric heater 27. What is necessary is just to be higher than the electrical resistance per unit length of one film-shaped heater longitudinal direction between a pair of electrodes in the single part which belongs to a heater. This is because, in at least one of the film heaters, temperature variation between the single part and the joint part can be suppressed.

1, 33, 47, 48, 61, 65 Film-like heater 3 Films 5a, 5b, 35a, 35b, 49a, 49b Electrodes 13, 43, 53 Heat generation layers 15, 37, 45 Energization suppression part 19 Single parts 17, 62, 66 Junction 18, 63, 67 Passage hole 27 Electric heater

Claims (4)

Provided with a plurality of film heaters (1, 33, 47, 48, 61, 65) arranged in a posture in which the neighbors face each other,
The plurality of film heaters include a plurality of joints (17, 62, 66) in which parts of two film heaters are joined to each other, and a part of one film heater is another film. A plurality of single parts (19) arranged away from the heater,
The plurality of film-like heaters are arranged such that each of the plurality of joint portions and each of the plurality of single portions are alternately arranged, whereby a plurality of passage holes (18, 63, 67).
Each of the plurality of film-like heaters includes a pair of electrodes (5a, 5b, 35a, 35b, 49a, 49b) disposed apart from each other on the electrically insulating film (3), and the insulating film And a heating layer (13, 43, 53) that is laminated to conduct between the pair of electrodes,
Of the two film-like heaters constituting each of the plurality of joint portions, at least one film-like heater has an energization suppressing portion (15, 37, 45) in the joint portion,
The electrical resistance per unit length in the longitudinal direction of the one film heater between the pair of electrodes in the energization suppressing unit belongs to the at least one film heater among the plurality of single parts. An electric heater characterized by being higher in electrical resistance per unit length in the longitudinal direction between the pair of electrodes in a single part.   An interval between the pair of electrodes in the energization suppressing portion is larger than an interval between the pair of electrodes in a single portion belonging to the at least one film heater among the plurality of single portions. The electric heater according to claim 1.   2. The electric heater according to claim 1, wherein the conductive heat generating material forming the heat generating layer is not laminated on the insulating film in a part or all of the energization suppressing portion.   Of the heat generation layer, the electrical resistivity of the heat generation layer constituting the portion disposed between the pair of electrodes in the energization suppressing portion belongs to the at least one film heater among the plurality of single portions. The electric heater according to any one of claims 1 to 3, wherein the electric heater has a higher electrical resistivity than that of the heat generating layer disposed between the pair of electrodes in the single part.

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