JPH0878207A - Positive characteristic thermistor device - Google Patents

Abstract

PURPOSE: To improve thermal efficiency by a method wherein a tabular positive characteristic thermistor element and a pair of power feeding terminals are mounted and they are mutually continued. CONSTITUTION: A pipe 13 is fitted to the through hole of a case 11, and after a flat terminal 16, a positive characteristic thermistor element 14 and a spring terminal 15 have been mounted on a recessed part from the side close to the through hole in such a manner that they are continued to electrodes 14a and 14b, the aperture part of the recessed part is covered by a cover 12. The positive characteristic thermistor element 14 generates constant heat by applying current to power feeding terminals 15 and 16, and the heat is transmitted to the pipe 13 through the flat part of a flat terminal 16 and the case 11. At this time, as one surface of the positive characteristic thermistor element 14 generates constant heat by applying current to power feeding terminals 15 and 16, and the heat is transmitted to the pipe 13 through the flat part of a flat terminal 16 and the case 11. At this time, as one surface of the positive characteristic thermistor element 14 is surface-contacted to the case 11 in the direction of the through hole through the flat part of the flat terminal 16, heat can be conducted easily. On the other hand, as the other surface of the positive characteristic thermistor 14 is brought into contact with the case 11 through an air layer K, heat is hardly conductive. Accordingly, the heat generated on the positive characteristic thermistor element 14 can be conductive to the pipe 13 in a highly efficient manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive temperature coefficient thermistor device used for a liquid type electronic mosquito trap and the like, and more particularly to a positive temperature coefficient thermistor device effectively utilizing heat generated by a positive temperature coefficient thermistor element.

[0002]

2. Description of the Related Art In recent years, positive temperature coefficient thermistor elements have been widely used in the field of heating elements. This is because the PTC thermistor element has a self-temperature control function, and has a feature that a highly safe PTC thermistor device can be obtained without a control circuit.

A conventional PTC thermistor device of this type will be briefly described with reference to FIG. The PTC thermistor device includes an inner cylinder 1a and an outer cylinder 1 which are arranged in a double manner.
b and the lower surface plate 1c are integrally formed into an insulating case 1,
A lid 2 that covers the upper opening of the insulating case 1, an eyelet 3,
The PTC thermistor element 4 is cylindrical and has electrodes formed on its upper and lower surfaces, and a pair of power supply terminals 5 and 6.

An assembly in which a pair of ring-shaped power supply terminals 5 and 6 having substantially the same shape are conductively connected to the upper and lower surfaces of the positive temperature coefficient thermistor element 4 is provided between the inner cylinder 1a and the outer cylinder 1b of the insulating case 1. And the gap between the insulating case 1 and the assembly is filled with the insulating resin 7. Then, the lid body 2 made of an insulating resin is fitted into the upper opening of the insulating case 1, and the eyelet 3
Are integrally fixed by means of a gap, and an air layer 8 is formed between the inner cylinder 1a and the eyelet 3 by a gap.

[0005]

However, the positive temperature coefficient thermistor device having such a structure has the following problems.

1. Since the positive temperature coefficient thermistor element 4 has a cylindrical shape, molding and firing are difficult, and warping is likely to occur, which requires post-processing such as lapping.

2. The heat transfer path from the PTC thermistor element 4 that has generated heat is the insulating resin 7, the insulating case 1a, the air layer 8, and the eyelet 3, and the heat transfer path from the PTC thermistor element 4 to the eyelet 3 is long and the thermal efficiency is poor.

3. Since the heat generated from the positive temperature coefficient thermistor element 4 is transferred to the entire insulating case 1 through the insulating resin 7, the heat transferred to the eyelet 3 is small compared to the entire heat generation amount.

The object of the present invention is to solve the above-mentioned problems, and uses a positive temperature coefficient thermistor element which is easy to process, and efficiently generates heat generated by this positive temperature coefficient thermistor element. To provide a positive temperature coefficient thermistor device.

[0010]

In order to achieve the above object, in a positive temperature coefficient thermistor device of the present invention, a case having a cylindrical through hole and a recess formed in the vicinity of the through hole, and both main surfaces are provided. A positive characteristic thermistor element in the form of a flat plate on which an electrode is formed, and a pair of power supply terminals, and the positive characteristic thermistor element and the pair of power supply terminals are loaded in the recess of the case, and the positive characteristic thermistor element is formed. The electrodes on both main surfaces are electrically connected to the pair of power supply terminals.

The pair of power supply terminals are composed of a spring terminal having the elastic contact portion at the other terminal and a flat terminal having a substantially flat plate at the one terminal, and the recess is provided in order from the through hole side. The flat terminal, the positive temperature coefficient thermistor element, and the spring terminal are mounted.

A metal pipe is arranged inside the through hole.

Further, a lid made of an insulating material is provided to cover the opening surface of the recess of the case.

The lid has a mounting base at its end.

Further, the lid body has a locking piece, the case has an engaging portion that engages with the locking piece, and the lid body is engaged with the case.

Further, the lid body is located in the through hole of the case and has a through hole of substantially the same shape, and the lid body is fixed to the case by the pipe.

Further, an inner lid for covering the opening surface of the recess is provided between the case and the lid.

Further, a narrow portion is provided on at least one of the pair of power supply terminals.

Further, the narrow portion is located in the recess of the case and is not in contact with the wall surface of the recess.

[0020]

According to the present invention, with the above-mentioned configuration, the heat transfer path is shortened to the power supply terminal, the insulating case, and the pipe, and the amount of heat generated by the PTC thermistor element can be efficiently used. Further, since the heat conduction of the air layer provided between the PTC thermistor element and the insulating case is poor in the direction in which heat is not desired to be transferred from the PTC thermistor element, wasteful heat dissipation is prevented.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described in detail with reference to FIGS. The positive temperature coefficient thermistor device 10 includes a case 11, a lid 12, and a metal pipe 1.
3, a plate-shaped positive temperature coefficient thermistor element 14 having electrodes 14a and 14b formed on both main surfaces, and a pair of power supply terminals 15 and 16
Composed of and.

The case 11 is made of, for example, an insulating inorganic material such as alumina, and has a cylindrical through hole 17 into which the pipe 13 can be press-fitted. In this example, a cylindrical through hole 17 and the through hole 17 are provided.
A concave portion 18 having an opening capable of accommodating the positive temperature coefficient thermistor element 14 and the pair of power feeding terminals 15 and 16 is formed in the vicinity of the positive temperature coefficient thermistor element 14 and one of the power feeding terminals. A protrusion 19 that restricts the movement of the spring terminal 15 described below is provided.

The lid 12 is made of, for example, an insulating inorganic material such as alumina or resin, and can cover the opening of the recess 18. However, a gap is formed between the case 11 and the lid 12 so that the pair of power supply terminals 15 and 16 can be led out.

The pipe 13 has, for example, a cylindrical shape made of aluminum having a good thermal conductivity, and is fitted in the through hole 17 of the case 11 with almost no gap.

One of the pair of power supply terminals 15 and 16 is a spring terminal 15 and the other is a flat terminal 16. The spring terminal 15 is made of a metal having elasticity, and one end thereof is connected to the electrode 14a of the positive temperature coefficient thermistor element 14. A spring portion 20 that elastically contacts and a lead portion 21 that is led to the outside of the case 11 are provided on the other end side, the flat terminal 16 is made of metal, and the electrode 14b of the positive temperature coefficient thermistor element 14 is provided on one end side thereof. A flat portion 22 that comes into contact with the lead portion 23, a lead portion 23 that is led to the outside of the case 11 on the other end side, and a narrow portion formed between them by a notch or slit in the width direction of the lead portion 23. And 24 are provided.

In the PTC thermistor device 10 made of such constituent members, the pipe 13 is fitted in the through hole 17 of the case 11, and the flat terminal 16 and the PTC thermistor element 14 are inserted in the recess 18 in order from the side close to the through hole 17. , The spring terminal 15 is connected to the electrodes 14a and 14b of the positive temperature coefficient thermistor element 14.
After being loaded so as to be electrically connected to each other, the opening of the recess 18 is covered with the lid 12. At this time, the positive characteristic thermistor 14 and the spring terminal 15 are restricted from moving in the direction of the narrow portion 24 of the flat terminal 16 by the protrusion 19 provided in the recess 18, and are insulated from the narrow portion 24 of the flat terminal 16. It is to maintain the state. In addition, a pair of power supply terminals 15,
The 16 lead portions 21 and 23 are led out of the case 11. Further, the narrow width portion 24 provided in the flat terminal 16 is bent from the flat surface portion 22, and the recess portion 18
Is disposed at a position where it does not abut the inner wall surface of the.

In the positive temperature coefficient thermistor 10 having such a structure, the positive temperature coefficient thermistor element 14 is heated at a constant temperature by energizing the pair of power supply terminals 15 and 16, and the heat is generated by the flat terminal 16.
It is conducted to the pipe 13 through the plane portion 22 and the case 11. At this time, one surface of the positive temperature coefficient thermistor element 14 is in surface contact with the case 11 in the direction of the through hole 17 through the plane portion 22, so that heat conduction is easy. On the other hand, since the other surface of the positive temperature coefficient thermistor element 14 comes into contact with the case 11 through the air layer K, heat conduction is difficult. Therefore, the heat generated by the positive temperature coefficient thermistor element 14 is efficiently conducted to the pipe 13. Further, the narrow portion 24 provided in the flat terminal 16 has a fuse function, and when an overcurrent flows through the positive temperature coefficient thermistor element 14, the narrow portion 24 disconnects.

In the present embodiment, the narrow portion 24 is connected to the flat terminal 16
However, it may be provided on the spring terminal 15.

Next, a second embodiment according to the present invention will be described in detail with reference to FIG. However, the same parts as those of the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. The present embodiment is different from the first embodiment in the lid 32.

This positive temperature coefficient thermistor device has a case 1
1, a lid 32, a metal pipe 13, a plate-shaped positive temperature coefficient thermistor element 14 having electrodes 14a and 14b formed on both main surfaces, and a pair of power supply terminals 15 and 16.

The lid 32 is provided with a mounting base 33 protruding from the side of the case 11 on the side of the lid 12 of the first embodiment.
Preferably, the base 33 is provided with a notch 34 for attachment such as a through hole or a female screw.

When a positive temperature coefficient thermistor device is constructed with each component including the lid 32, a mounting base 33 is formed.
Protrude from the side of the case 11. This mounting base 3
3 itself, or through hole or female screw 34
It is possible to easily attach and fix the PTC thermistor device to another body by screwing the PTC thermistor device.

The shapes of the mounting base 33 and the through hole or the female screw 34, and the mounting method are not limited to these.

Further, a third embodiment of the present invention will be described in detail with reference to FIG. However, the same parts as those of the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. This embodiment is case 1 in the first embodiment.
1 and a part of the lid 12 are different.

This positive temperature coefficient thermistor device has a case 4
1, a lid 42, a metal pipe 13, a plate-shaped positive temperature coefficient thermistor element 14 having electrodes 14a and 14b formed on both main surfaces thereof, and a pair of power supply terminals 15 and 16.

The case 41 is provided with engaging portions 43, 43 composed of a pair of grooves or the like on the bottom surface side of the recess 18.
The through hole 17, the recess 18, and the protrusion 19 are formed in the same manner as the case 11 of the first embodiment.

The lid 42 is provided with a pair of locking pieces 44, 44 on both sides of the lid 12 of the first embodiment.
The locking pieces 44, 44 extend to the bottom surface along the side portions of the case 41 and are engaged with the engaging portions 43, 43.

Using the respective constituent members including the case 41 and the lid 42, the locking pieces 44, 44 provided on the lid 42 are provided.
By engaging with the engaging portions 43 of the case 41, the positive temperature coefficient thermistor device can be easily assembled.

The lid 42 of the present embodiment is provided with a mounting base 33 provided on the lid 32 of the second embodiment so that the positive temperature coefficient thermistor device can be easily attached to another body. May be.

Furthermore, a fourth embodiment of the present invention will be described in detail with reference to FIG. However, the first
The same parts as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, a part of the lid 12 and the pipe 13 in the first embodiment are different.

This positive temperature coefficient thermistor device has a case 1
1, a lid 52, a metal pipe 53, a plate-shaped positive temperature coefficient thermistor element 14 having electrodes 14a and 14b formed on both main surfaces, and a pair of power supply terminals 15 and 16.
However, since the lead portions 21 and 23 shown in FIG. 1 have different directions, the case 11 and the pair of power supply terminals 15 and 16 have different shapes.

The lid 52 can cover the vicinity of the through hole 17 of the case 11 and the opening of the recess 18,
It has a through hole 54 which is located in the through hole 17 and has substantially the same shape.

The pipe 53 has an eyelet shape having a collar 55 at one end.

When a positive temperature coefficient thermistor device is constructed with the respective components including the lid 52 and the pipe 53, the through hole 54 provided in the lid 52 is the through hole 1 of the case 11.
It is located at 7 and is apparently one through hole. The case 11 and the lid 52 are integrally fixed and assembled by inserting the pipe 53 into this apparently one through hole and caulking one end portion without the collar 55.

In the positive temperature coefficient thermistor device having such a structure, when the lid 52 is attached to the case 11, the lid 52 covering the recess 18 of the case 11 is easily fixed by caulking the pipe 53.

Incidentally, as shown in the one-dot chain line circle in the figure, the lid 5
The second through hole 54 may be partially cut away. Further, as in the second embodiment, a mounting base (not shown) may be provided on the side portion of the lid body 52 if necessary.

Furthermore, a fifth embodiment of the present invention will be described in detail with reference to FIG. However, the first
The same parts as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, an inner lid 63 is added to the fourth embodiment, and a lid 52 is provided with a mounting base.

This positive temperature coefficient thermistor device has a case 1
1, a lid 62, an inner lid 63, a metal pipe 53,
Electrodes 14a and 14b are formed on both main surfaces, and it is composed of a plate-shaped positive temperature coefficient thermistor element 14 and a pair of power supply terminals 15 and 16.

Like the lid 52 shown in FIG. 6, the lid 62 can cover the opening side of the case 11, and has a through hole 64 located in the through hole 17 and having substantially the same shape. Further, mounting bases 65, 65 projecting from the side of the case 11 are provided on the side portions of the lid 62, and preferably the mounting bases 65, 65 have notches 66 for mounting such as through holes or female screws. 66 is formed.

The inner lid 63 is made of, for example, a nonflammable insulator such as mica, and covers the recess 18 of the case 11.

When the PTC thermistor device is constructed with the respective components including the inner lid 63, the PTC thermistor element 14 and the pair of feeding terminals 1 are formed in the recess 18 of the case 11.
5, 16 are loaded, the inner lid 63 covers the opening of the recess 18, the lid 62 covers the outer side thereof, and the inner lid 63 is interposed between the case 11 and the lid 62.

In the positive temperature coefficient thermistor device having such a structure, the positive temperature coefficient thermistor element 14 is surrounded by the case 11 and the inner lid 63 which are made of a non-combustible insulator, so that the heat resistance is increased regardless of the material of the lid 62. .

The lid 62 in this embodiment is the lid 12, 32, 42 used in the other embodiments (in this case, 4
1) or 52 or the like.

Further, the lids 12, 32, 42, 52, 62
Is preferably formed of a non-combustible material.

Further, in the first to fifth embodiments, case 1 is used.
Although the example in which the pipes 13 and 53 are fitted to the pipes 1 and 41 has been described, the same effect can be obtained without using the pipes 13 and 53.

[0056]

As described above, the positive temperature coefficient thermistor device according to the present invention has the following effects.

1. Since the PTC thermistor element has a plate-like shape, it can be easily molded and fired, and warpage is less likely to occur, and post-processing such as lapping is unnecessary.

2. The heat transfer path from the PTC thermistor element that has generated heat is a flat terminal, an insulating case, and a pipe. Since the heat transfer path from the PTC thermistor element to the pipe is short and does not involve an air layer, thermal efficiency is good.

3. Since the heat generated from the positive temperature coefficient thermistor element is transferred to the case through the air layer except for the necessary portion, there is little waste in the heat transfer path, and heat is efficiently transferred to the pipe.

[Brief description of drawings]

FIG. 1 is a perspective view of a positive temperature coefficient thermistor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an exploded perspective view of FIG.

FIG. 4 is an exploded perspective view of a PTC thermistor device according to a second embodiment of the present invention.

FIG. 5 is an exploded perspective view of a positive temperature coefficient thermistor device according to a third embodiment of the present invention.

FIG. 6 is an exploded perspective view of a positive temperature coefficient thermistor device according to a fourth embodiment of the present invention.

FIG. 7 is an exploded perspective view of a positive temperature coefficient thermistor device according to a fifth embodiment of the present invention.

FIG. 8 is a conventional cross-sectional view.

[Explanation of symbols]

11, 41 Case 12, 32, 42, 52, 62 Lid 13, 53 Pipe 14 Positive Characteristic Thermistor Element 14a, 14b Electrode 15, 16 Pair of Power Supply Terminals (Spring Terminal, Flat Terminal) 17 Through Hole 18 Recess 24 24 Narrow Width Part 33 Mounting base 43 Engaging part 44 Locking piece 54 Through hole 63 Inner lid

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyofumi Torii 2 26-10 Tenjin Tenjin, Nagaokakyo City, Kyoto Murata Manufacturing Co., Ltd.

Claims (10)

[Claims] 1. A case having a cylindrical through hole and a recess formed in the vicinity of the through hole, a plate-shaped positive temperature coefficient thermistor element having electrodes formed on both main surfaces thereof, and a pair of power supply terminals.
The positive temperature coefficient thermistor element and the pair of power feeding terminals are loaded in the recess of the case, and the electrodes on both main surfaces of the positive temperature coefficient thermistor element and the pair of power feeding terminals are electrically connected to each other. Characteristic PTC thermistor device. 2. The pair of power supply terminals comprises a spring terminal having the elastic contact portion at the other terminal and a flat terminal having a substantially flat plate at the one terminal, and the recess is provided in order from the through hole side. The positive temperature coefficient thermistor device according to claim 1, wherein the flat terminal, the positive temperature coefficient thermistor element, and the spring terminal are mounted. 3. The positive temperature coefficient thermistor device according to claim 1, wherein a metal pipe is provided inside the through hole. 4. The positive temperature coefficient thermistor device according to claim 1, further comprising a lid body made of an insulating material and covering an opening surface of the recess of the case. 5. The positive temperature coefficient thermistor device according to claim 4, wherein the lid has a mounting base at an end thereof. 6. The lid has an engaging piece, the case has an engaging portion that engages with the engaging piece, and the lid is engaged with the case. Claim 4 or 5
The positive temperature coefficient thermistor device described in. 7. The lid body is located in the through hole of the case and has a through hole of substantially the same shape, and the lid body is fixed to the case by the pipe. , 5 or 6, the positive temperature coefficient thermistor device. 8. The positive temperature coefficient thermistor device according to claim 4, wherein an inner lid is provided between the case and the lid to cover the opening surface of the recess. . 9. The positive temperature coefficient thermistor device according to claim 1, wherein a narrow portion is provided on at least one terminal of the pair of power supply terminals. 10. The positive temperature coefficient thermistor device according to claim 1, wherein the narrow portion is located in the recess of the case and does not contact the wall surface of the recess.