JPH09148050A - Ptc heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a PTC heater, capable of freely selecting the shape of a heater and having high output and high reliability, by specifying the structure of the PTC heater, in a PTC heater used as the heat source of a heating heater such as a clothing dryer. SOLUTION: This structure is provided with: a case 12 having an opening part on an upper part; a platelike PTC thermistor element 11 housed in the case 12, and also having a pair or more of comb type electrodes 17a on a surface; a pair of electrode plates 14a and 14b electrically connected to the thermistor element 11, and also extracted outside the case 12; a pair or more of coil springs 13 provided in the inside of the case 12 so as to retain the electrode plates 14a and 14b; an insulating plate 16 provided on the thermistor element 11; and a heat slinger 15 provided on the insulating plate 16, and also provided so as to cover the opening part of the case 12. That is, by making conventional spring pressure-contact structure into coil spring structure, a small spring can be usable, a spring-occupying space can be reduced, and the shape of a heater can be freely selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PTC heater having a spring pressure contact structure used as a heat source for a heater for heating clothes dryers, electronic mosquito traps, humidifiers and the like.

[0002]

2. Description of the Related Art Recently, in the PTC heater market, a small size, high output and high reliability heater is desired. Particularly for higher output, a heating element having an electrode structure called a comb-shaped electrode described in Japanese Patent Publication No. 56-14221 is known. FIG. 7 shows a perspective view of the surface of the element using the comb-shaped electrode, and FIG. 8 shows a perspective view of the back surface of the element using the comb-shaped electrode.

A conventional PTC heater will be described below. FIG. 9 is a sectional view of a conventional PTC heater having a spring pressure contact structure. FIG. 10 is a perspective view of a conventional PTC heater having a spring pressure contact structure. 1 is a plate-shaped positive temperature coefficient thermistor element (hereinafter referred to as PT) having a comb-shaped electrode 1a on one main surface.
C element), 2 is a case, 3a is a plate-like spring terminal, 3b is a plate-like spring terminal, 5 is a heat radiating plate, and 6 is an insulating plate. A conventional PTC heater having a spring pressure contact structure has a plate-like spring terminal 3
Mostly, the structure has a structure in which the PTC element 1 is fixed to the insulating plate 6 by a and 3b, and an unheated object existing on the upper part of the heat radiating plate 5 is heated through the insulating plate 6 and the heat radiating plate 5. It was

[0004]

Generally, a plate-shaped spring terminal has long-term reliability unless the stress per unit area generated inside the spring is designed to be equal to or less than the maximum bending stress of the material used. I can't get sex. for that reason,
It is necessary to design the total length of the spring to be a certain length or more, and there is a problem that the heater shape is enlarged. It is an object of the present invention to provide a PTC heater whose heater shape can be freely selected.

[0005]

In order to achieve this object, a PTC heater according to the present invention is a plate-like member having a case having an opening at the top and at least a pair of comb-shaped electrodes housed in the case. Of the PTC thermistor element, a pair of electrode plates electrically connected to the PTC thermistor element and drawn out of the case, at least a pair of coil springs provided inside the case to hold the electrode plate, In this structure, an insulating plate provided on the PTC thermistor element and a heat radiating plate provided on the insulating plate so as to cover the opening of the case are provided.

With this structure, the total length of the spring is not related to the internal stress of the spring, and a small spring can be used.
The space occupied by the spring can be very small. Further, it is possible to easily provide a heater that needs to be fixed with a high spring pressure by arranging a plurality of coil springs without increasing the internal stress of each spring and by only increasing the space. As a result, the shape of the heater can be freely selected.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention includes a case, a plate-shaped PTC thermistor element housed in the case, and a PTC thermistor element provided so as to be electrically connected to the case. The PTC thermistor element is provided with a pair of electrode plates, at least a pair of coil springs provided to hold the electrode plates, and a heat radiating plate provided on the PTC thermistor element via the case. Since at least a pair of comb-shaped electrodes are provided on the surface of the device, and the space occupied by the spring can be reduced, the shape of the heater can be freely selected.

According to a fourth aspect of the present invention, there is provided a case having an opening at the top, a plate-shaped PTC thermistor element which is housed in the case and has at least a pair of comb-shaped electrodes on the surface, and the PTC thermistor element. An insulating plate provided on the upper portion and having an electrode on the surface, at least a pair of electrode plates provided on the lower portion of the insulating plate and electrically connected to the PTC thermistor element via the electrode, and to hold the electrode plate. At least a pair of coil springs provided inside the case, and a heat radiating plate provided on the insulating plate so as to cover the opening of the case, and an electrode provided on the PTC thermistor element by this configuration. The productivity can be improved because the number can be reduced.

In the invention according to claim 2 or 5, the case has a double structure, and the outer case is made of resin, porcelain, stainless steel, aluminum, copper or zinc, and the inner case is insulated. If the PTC thermistor element is changed inside the case, the influence on the outside can be reduced by using the double structure.
In addition, when the outer case is made of metal, the heat dissipation performance as a whole is improved.

The invention according to claim 3 or 6 is one in which a resin having good heat conductivity is applied to at least the surface of the heat dissipation plate on the insulating plate side, and heat can be more efficiently transferred to the object to be heated. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view of a PTC heater according to the present embodiment. FIG. 2 is a perspective view of the PTC heater of this embodiment. Reference numeral 11 is a plate-shaped PTC thermistor element (hereinafter referred to as PTC element), 12 is a case, 13 is a coil spring, 14a and 14b are electrode plates, 15 is a heat radiating plate, and 16 is an insulating plate. The PTC element 11 is a semiconductor element containing barium titanate as a main component, and is made of silver, aluminum, zinc or the like, and a comb-shaped electrode 17a is printed on the front surface, a side surface electrode 17b is printed on the side surface, and a back surface electrode 17c is printed on the back surface. The shape is a square plate or a disk and has a thickness of 1.0 mm to 5.0 mm. The case 12 is made of an insulating material such as resin such as PPS or porcelain such as alumina steatite. The coil spring 13 is made of a metal having a spring property such as stainless steel and phosphor bronze, and is made of electrode plates 14a and 14b.
Is a metal such as stainless steel or copper. The insulating plate 16 is
An insulating porcelain having good thermal conductivity, such as alumina, is used. Assemble and use the heater in Case 12
The coil spring 13 is arranged inside the electrode plate, and the electrode plates 14a and 14b are arranged above the coil spring 13,
The PTC element 11 is arranged on the upper part of 4b, and the coil spring 13
Pressurizes the electrode plates 14a and 14b, so that the PTC
The element 11 is fixed to the insulating plate 16. The heat radiating plate 15 is arranged above the insulating plate 16, the heat radiating plate 15 is caulked to the case 12, power is supplied to the electrode plates 14a and 14b, and the object to be heated existing above the heat radiating plate 15 is heated. In addition, the heat sink 15
A resin (not shown) having good thermal conductivity such as heat dissipation grease may be applied between the insulating plate 16 and the insulating plate 16, and between the PTC element 11 and the insulating plate 16.

Since the PTC heater in this embodiment uses the coil spring, the space occupied by the spring can be made extremely small.

(Second Embodiment) FIG. 3 is a sectional view of a PTC heater according to the present embodiment. FIG. 4 is a perspective view of the PTC heater of this embodiment. 11 is a PTC element, 13
Is a coil spring, 14a and 14b are electrode plates, 15 is a heat dissipation plate, 16 is an insulating plate, 17a is a comb-like electrode, 17b is a side surface electrode, and 17c is a back surface electrode. The above is the PTC shown in FIG.
It has the same structure as the heater. The difference from the configuration of the first embodiment is that the case 12 has a double structure of an outer case 12a and an inner case 12b arranged inside the outer case 12a. The outer case 12a is made of any one of stainless steel, aluminum, copper, and zinc, and the inner case 12b is made of flame-retardant resin such as PPS or porcelain such as alumina or steatite. The method of assembling and using the heater is the same as that of the first embodiment after disposing the inner case 12b inside the outer case 12a.

Further, as in the first embodiment, the heat sink 15
A resin (not shown) such as heat radiation grease may be applied between the insulating plate 16 and the insulating plate 16, and between the PTC element 11 and the insulating plate 16.

The outer case 12a may have a single plate shape (not shown) as well as a box shape. According to this configuration,
Since the case 12 is doubled and the outer case 12a is made of metal, the overall heat dissipation performance is improved.

(Third Embodiment) FIG. 5 is a sectional view of a PTC heater according to the present embodiment. FIG. 6 is a perspective view of the PTC heater of this embodiment. 11 is a PTC element, 12
Is a case, 13 is a coil spring, 13a is a plate spring, 14
a and 14b are electrode plates, 15 is a heat dissipation plate, 16 is an insulating plate, 1
Reference numeral 7a is a comb-shaped electrode, and 17d is an extension electrode. The difference from the first embodiment is that the PTC element 11 and the extension electrode 17d provided on the insulating plate 16 are present, the side surface electrode 17b and the back surface electrode 17c are not present, and that the PTC element 11 is held by the plate spring 13a. It is a point to do in. Further, the extension electrode 17d is obtained by printing and baking a paste electrode of silver, aluminum, nickel or the like on the insulating plate 16 according to the first embodiment.
The width of the PTC element 11 used in No. 2 is approximately the same as the common electrode 17b plus 5 mm to 10 mm. The heater is assembled and used by arranging the plate spring 13a and the coil spring 13 inside the case 12, disposing the electrode plates 14a and 14b above the coil spring 13, and disposing the electrode plates 14a and 14b. Between the PTC element 1
1 is arranged, and the insulating plate 16 is arranged so that the extension electrode 17d is located at a position where the common electrode portion 17b of the PTC element 11 and the electrode plates 14a and 14b can be electrically connected. The heat radiating plate 15 is arranged above the insulating plate 16, the heat radiating plate 15 is caulked to the case 12, power is supplied to the electrode plates 14a and 14b, and the object to be heated existing above the heat radiating plate 15 is heated. .

Further, between the heat sink 15 and the insulating plate 16, PT
A resin (not shown) such as heat-dissipating grease may be applied between the C element 11 and the insulating plate 16. As shown in the second embodiment, the case 12 may be replaced by the case 12a, the case 12 or the case 12a.
It may be a structure separated from b (not shown) into a double structure. In addition, at least one leaf spring 13a or a coil spring (not shown) is arranged below the PTC element 11 to provide the PTC
The element 11 can be fixed.

In the first to third embodiments, the coil spring 13 is brought into contact with the electrode plates 14a and 14b to bring the electrode plate 1 into consideration.
4a and 14b are fixed. Two coil springs 13 and electrode plates 14a and 14b are provided.
It is possible to more stably indicate the PTC thermistor element 11. Further, the coil spring 13 is preferably made of stainless steel or the like, but may be made of metal as long as it has heat resistance and proof stress, and the number of turns may be any number as long as the spring pressure can be secured.

The electrode plates 14a and 14b are preferably formed of a material such as copper having a low contact resistance, and any material can be used as long as it can conduct electricity. In this manner, the conventional leaf spring has the role of the coil spring 13 and the electrode plate 14a.
14b, it is possible to increase the degree of freedom in terms of shape and material selection.

[0020]

As described above, in the PTC heater of the present invention, by using the coil spring instead of the leaf spring, it is possible to obtain a PTC heater having a free shape and high output and high reliability. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heating surface side of a PTC heater according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a heating surface side of the PTC heater according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a heating surface side of a PTC heater according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a heating surface side of a PTC heater according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a heating surface side of a PTC heater according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a heating surface side of a PTC heater according to a third embodiment of the present invention.

FIG. 7 is a perspective view of the surface of a plate-shaped PTC thermistor element having comb-shaped electrodes.

FIG. 8 is a perspective view of the back surface of a plate-shaped PTC thermistor element having comb-shaped electrodes.

FIG. 9 is a cross-sectional view of a heating surface side of a conventional PTC heater having a spring pressure contact structure.

FIG. 10 is a perspective view of a heating surface side of a conventional PTC heater having a spring pressure contact structure.

[Explanation of symbols]

 11 plate-like PTC thermistor element 12 case 12a outer case 12b inner case 13 coil spring 14a electrode plate 14b electrode plate 15 heat sink 16 insulating plate 17a comb-shaped electrode

Claims (6)

[Claims] 1. A case having an opening at the top, a plate-shaped PTC thermistor element housed in the case and having at least a pair of comb-shaped electrodes on the surface, and the PT.
A pair of electrode plates electrically connected to the C thermistor element and drawn out of the case, at least a pair of coil springs provided inside the case so as to hold the electrode plates, and provided on the PTC thermistor element. A PTC heater comprising an insulating plate and a heat radiating plate provided on the insulating plate so as to cover the opening of the case. 2. The case has a double structure, and the outer case is made of resin, porcelain, stainless steel, aluminum,
The PTC heater according to claim 1, wherein the PTC heater is made of copper or zinc, and the inner case is made of an insulating resin or porcelain. 3. The PTC heater according to claim 1, wherein a resin having good thermal conductivity is applied to at least the surface of the heat dissipation plate on the insulating plate side. 4. A case having an opening at the top, a plate-shaped PTC thermistor element housed in the case and having at least a pair of comb-shaped electrodes on the surface, and the PT.
An insulating plate provided on the top of the C thermistor element and having electrodes on the surface, at least a pair of electrode plates provided on the lower side of the insulating plate and electrically connected to the PTC thermistor element via the electrodes, and this electrode plate A PTC heater including at least a pair of coil springs provided inside the case so as to hold the heat dissipation plate, and a heat dissipation plate provided on the insulating plate so as to cover the opening of the case. 5. The case has a double structure, and the outer case is made of resin, porcelain, stainless steel, aluminum,
The PTC heater according to claim 4, wherein the PTC heater is made of copper or zinc, and the inner case is made of an insulating resin or porcelain. 6. The PTC heater according to claim 4, wherein a resin having good heat conductivity is applied to at least the surface of the heat dissipation plate on the insulating plate side.