JPH0845704A - Positive characteristic thermistor device - Google Patents

Abstract

PURPOSE:To increase heat generating efficiency by a method wherein PTC element held by a pair of feeding terminals is further held by a pair of flat plate parts of a heat radiating plate 5 comprising a cylindrical part with an insulator and said flat plate parts to be contained in an insulating case. CONSTITUTION:A PTC element 2 is held by a pair of feeding terminals 1a, 1b. Next a holding part having spring property is provided on the contact part of the PTC element 2 to be inserted into an elastic insulating tube 3. Furthermore, the previously assembled insulating tube 3 is held between the flat plate parts 7 of a heat radiating plate 5 comprising a cylindrical part 6 and a pair of flat plate parts 7 to be contained in an insulating case 9. Through these procedures, a heat conductive path is made shorter to increase the heat generating efficiency as well as the heat radiating efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a positive temperature coefficient thermistor device which can be used as a liquid liquid-only cutting device.

[0002]

2. Description of the Related Art Conventionally, a positive temperature coefficient thermistor device used in a liquid-type electric cutting device is shown in FIG. The positive temperature coefficient thermistor device 21 used in this liquid system is assembled as follows. That is, as shown in FIG. 5, a heating tubular portion 22 provided upright in the central portion is provided, and in an annular groove portion 24 formed over the entire circumference of the tubular portion 22 of the insulating case 23 having an upper surface opening, A ring-shaped positive temperature coefficient thermistor element (hereinafter abbreviated as PTC element) in which electrodes are formed on both surfaces of the ring-shaped electrode plate 26 delivered to the ring-shaped electrode plate 26 having the lead portion 2 2
7 is delivered, and the lead portion 28 is further provided on the PTC element 27.
A ring-shaped electrode sheet 29 is attached, and a ring-shaped insulating sheet 30 is stacked on the upper surface of the insulating case 23. After the potting resin (not shown) is filled in the insulating case 23, a metal eyelet 32 such as aluminum is inserted into the through hole 31 of the insulating sheet 30 and the heating cylinder portion 22 of the insulating case 23. As shown in FIG. 6, both ends of the metal eyelet 32 are caulked to the insulation sheet 30 and the insulation case 23, and the insulation sheet 30 and the insulation case 23 are integrally assembled by the metal eyelet 32.

The metal eyelets 32 play the following roles. That is, since the insecticidal liquid contains a component that shortens the life of the PTC element 27, the seam between the upper end surface of the tubular portion 22 facing the vaporization core and the insulating sheet 30 is prevented by the metal eyelet 32. Covering.

The PTC thermistor device 21 is used by inserting a vaporization core for sucking insecticidal liquid into the metal eyelet 32 and using the lead parts 25 and 28 from the PTC element 2.
When electricity is applied to 7, heat generated from the PTC element 27 causes the heating tubular portion 22 of the insulating case 23 to heat the metal eyelet 32, and the metal eyelet heats the vaporization core to evaporate the insecticidal liquid. .

[0005]

However, the conventional PTC thermistor device has the following problems.

First, since a ring-shaped PTC element is used, it is difficult to mold and fire the PTC element. In addition, post-processing such as wrapping is necessary because it tends to warp.

Secondly, the heat generation path has a PTC element-terminal plate-
Resin-insulation case-air layer-eyelet, the heat generation path to the target eyelet is long, and the thermal efficiency is poor.

Thirdly, since the heat from the PTC element is transferred to the insulating case through the resin, it is necessary to consider the material used for the insulating case. Further, since the reliability decreases as the temperature increases, the structure shown in FIG. 5 decreases in reliability.

Fourthly, since the heat from the PTC element is transferred to the insulating case through the resin, the amount of heat to be transferred to the eyelet escapes to the insulating case, resulting in poor thermal efficiency.

The present invention has been made in order to solve the above-mentioned problems, and has a positive temperature coefficient which is excellent in heat generation efficiency, excellent in reliability and safety, and which can be used as a liquid-liquid-only scaling device. It is intended to provide a thermistor device.

[0011]

In order to achieve the above object, the present invention relates to a first aspect of the invention, in which a PTC element sandwiched by a pair of power supply terminals is paired with a cylindrical portion via an insulator. The heat radiation plate is sandwiched by the flat plate portion of the heat radiation plate and the flat plate portion excluding the cylindrical portion of the heat radiation plate is housed in the insulating case.

The invention according to claim 2 is characterized in that the insulator is made of an insulating material having elasticity.

The invention according to claim 3 is characterized in that the insulator is a tubular insulator having elasticity.

The invention according to claim 4 is characterized in that the insulator is a heat-shrinkable tube having elasticity.

According to a fifth aspect of the present invention, the pair of power supply terminals have a spring property at the contact portion with the PTC element, and
The PTC element and the power feeding terminal are in surface contact with each other in a state where the TC element, the power feeding terminal and the insulator are housed in an insulating case.

According to a sixth aspect of the present invention, in the positive temperature coefficient thermistor device, the PTC element thickness + (feeding terminal thickness ×
2) + (insulating material thickness × 2) (a) and the dimension (b) between the pair of flat plate portions of the heat dissipation plate have a relationship of (a)> (b).

[0017]

Since the PTC thermistor device of the present invention has the above-mentioned structure, the PTC element, the power supply terminal, the insulating tube, and the heat sink and the heat conduction path are short, so that the heat generation efficiency is good and the heat dissipation plate has a cylindrical portion. The heat conduction loss can be improved and the temperature of the insulating case can be lowered. Further, by making the contact portion between the power supply terminal and the PTC element a weak spring shape, the reliability against sparks and the like can be improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A positive temperature coefficient thermistor device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view of the PTC thermistor device. 2 is a sectional view,
FIG. 3 is a partially enlarged sectional view.

In FIG. 1, the power supply terminals 1a and 1b are made of stainless steel and sandwich the PTC element 2.
Retaining portions 4a and 4b having a spring property due to cut and raised are provided at the contact portion with the C element. PTC element 2
The power supply terminals 1a and 1b sandwiched between are inserted in an insulating tube 3 made of an elastic silicon material.

Further, in FIG. 1, the heat dissipation plate 5 has a cylindrical portion 6
And a pair of flat plate portions 7. The heat dissipation plate 5 is made of aluminum, for example.

The PTC element 2 combined as described above,
The power supply terminals 1a and 1b and the insulating tube 3 are connected to the heat sink 5
The flat plate portion 7 is sandwiched between the flat plate portion 7 and the flat plate portion 7 and housed in the insulating case 9.

The insulating case 9 includes a PTC element 2, power supply terminals 1a and 1b, an insulating tube 3, a heat radiating plate 5 (cylindrical portion 6).
A concave portion 10 for accommodating the heat sink 5 and a protrusion 11 such that the contact portion with the heat sink 5 makes a line contact on the inner side surface thereof.
have. In addition, the cylindrical portion 6 of the heat sink 5 is an insulating case 9
A groove 12 is provided on the left side wall in the drawing so as to go outside. Further, the ends of the power supply terminals 1a and 1b are insulated cases 9
A groove 13 is provided on the right side wall in the drawing so that the groove 13 is exposed to the outside. In this structure, the flat plate portion 7 is provided with the protrusion 8 near the cylindrical portion 6, so that it is possible to prevent the blank after the insertion into the insulating case 9.

Further, a lid 14 made of polyphenylene sulfide (PPS) is attached from the top to form a simple sealed structure.

A protrusion 11 is provided inside the insulating case 9 to prevent heat from the PTC element 2 from being transferred to the insulating case 9 through the heat dissipation plate 5. Therefore, the heat conduction loss to the cylindrical portion 6 of the heat dissipation plate 5 can be improved, and the heat generation temperature of the insulating case 9 can be lowered.

Further, as shown in FIGS. 3A and 3B, the contact portion between the power feeding terminals 1a and 1b and the PTC element 2 is the power feeding terminal 1
By making the holding portions 4a, 4b of the a, 1b spring-shaped, the PTC element 2 is fed to the feeding terminals 1a, 1b in a state where the PTC element 2, the feeding terminals 1a, 1b, and the insulating tube 3 are housed in the insulating case 9. It is made to come into surface contact with.

Further, as shown in FIGS. 3B and 3C, P
The relation between the dimension (a) of TC element thickness + (feeding terminal thickness × 2) + (insulating material thickness × 2) and the dimension (b) between the pair of flat plate portions 6 of the heat dissipation plate 5 is (a)> (b). Since the pressing force using the elasticity of the insulating material and the pressing force by the spring of the power supply terminals 1a and 1b can be applied to the PTC element 2 by being formed so as to improve the reliability against sparks and the like. .

In this embodiment, the power supply terminal material is stainless steel, but other metal materials such as beryllium copper and phosphor bronze having a spring property and the heat radiating plate are brass or C.
A material having good thermal conductivity such as u may be used.

The insulating tube may be made of a material having elasticity other than silicon, which has good thermal conductivity. In addition, as the insulating tube, a heat-shrinkable tube having elasticity (such as silicon) may be used. When using this heat-shrinkable tube, the PTC element is sandwiched by a pair of spring-shaped power supply terminals, inserted into the elastic heat-shrinkable tube, and then the heat-shrinkable tube is shrunk before radiating heat. It can be sandwiched between plates (not shown). By using the heat-shrinkable tube having elasticity as described above, positioning of the PTC element and the power supply terminal is facilitated and assembly is facilitated.

Further, in this embodiment, the lid is used as a simple hermetically sealed structure in the insulating case. However, instead of the lid, the insulating case is filled with resin (silicon-based, epoxy-based, etc.) for insulation. The inside of the case may be sealed.

The above-mentioned positive temperature coefficient thermistor device can be used as a liquid-only scalper.

FIG. 4 is a cross-sectional view of a liquid-only caterpillar. The liquid-only catrilator is assembled as follows. The chemical solution bottle 15 containing the insecticidal solution is placed in the bottle storage chamber 16 provided in the case 17. The chemical liquid bottle 15 is made of, for example, a felt-like or fibrous vaporization wick 18 capable of sucking up a liquid by a capillary phenomenon.
The lower part is immersed in insecticide, and the upper end is projected upward. Then, the positive temperature coefficient thermistor device 19 shown in FIG. 1 is housed in the case 17 so that the upper portion of the vaporization core 18 is inserted into the cylindrical portion 6 of the heat dissipation plate 5, and the lid 20 is covered. In this way, when the PTC element 2 of FIG. 1 is energized to generate heat, heat is conducted from the PTC element 2 to the vaporization core 18, and the vaporization core 18 can be heated. From the heated vaporization wick 18, the sucked insecticidal liquid is evaporated and diffused to the surroundings.

[0032]

As described above, according to the present invention, the following effects can be obtained.

First, since the heat conduction path is short, that is, the PTC element-the power supply terminal-the insulator-the heat sink, the heat generation efficiency is good. Also,
Since both sides of the electrodes of the PTC element are used as heat dissipation points, it is possible to provide a positive temperature coefficient thermistor device that can efficiently take out heat of the PTC element.

As a result, the Curie point of the PTC element used can be lowered, and the heat resistance of the materials used such as the insulating case and lid can be lowered. Furthermore, the surface temperature of the parts used, excluding the heat generating part, can be lowered, and reliability and safety can be improved.

Secondly, by utilizing the elasticity of the spring and the insulating tube as a contact method (pressing method) between the PTC element and the power supply terminal, a positive temperature coefficient thermistor device for improving reliability such as spark of the contact is provided. can do.

Thirdly, the power feeding terminal is provided with elasticity, and after the insertion into the insulating case, the PTC element and the power feeding terminal are in surface contact with each other, so that a positive temperature coefficient thermistor device having high heat generation efficiency can be provided. .

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a positive temperature coefficient thermistor device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the positive temperature coefficient thermistor device according to the present embodiment.

FIG. 3 is a partially enlarged cross-sectional view of the positive temperature coefficient thermistor device according to the present embodiment.

FIG. 4 is a schematic cross-sectional view of a liquid-only scaly device using the positive temperature coefficient thermistor device of the present invention.

FIG. 5 is an exploded perspective view showing a conventional positive temperature coefficient thermistor device.

FIG. 6 is a sectional view of FIG. 5;

[Explanation of symbols]

 1a, 1b ... Power supply terminal 2 ... PTC element 3 ... Insulation tube 4a, 4b ... Holding part 5 ... Radiating plate 6 ... Cylindrical part 7 ... Flat plate part 9 ... Insulation case 11 ... Projection part 15 ... Chemical liquid bottle 18 ... Vaporization core

Claims (6)

[Claims] 1. A PTC element sandwiched by a pair of power supply terminals is sandwiched by the flat plate portion of a heat radiating plate composed of a cylindrical portion and a pair of flat plate portions via an insulator, and the cylindrical portion of the heat radiating plate is A positive temperature coefficient thermistor device characterized in that the removed flat plate part is housed in an insulating case. 2. The PTC thermistor device according to claim 1, wherein the insulator is made of an insulating material having elasticity. 3. The PTC thermistor device according to claim 1, wherein the insulator is a tubular insulator having elasticity. 4. The positive temperature coefficient thermistor device according to claim 1, wherein the insulator is a heat-shrinkable tube having elasticity. 5. The pair of power supply terminals has a spring property at a contact portion with the PTC element, and when the PTC element, the power supply terminal and the insulator are housed in an insulating case, the PTC element and the power supply terminal are A surface contact is made, The claim 1 characterized by the above-mentioned.
The positive temperature coefficient thermistor device described in. 6. In the positive temperature coefficient thermistor device, P
The relationship between the dimension (a) of TC element thickness + (feeding terminal thickness × 2) + (insulating material thickness × 2) and the dimension (b) between the pair of flat plate portions of the heat dissipation plate is (a)> (b). The positive temperature coefficient thermistor device according to claim 1 or 5, wherein.