JPH0950902A - Positive temperature characteristic thermistor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently transmit heat generated in a positive temperature characteristic element to a radiating cylinder by electrically connecting the electrode of both main surfaces of a positive temperature characteristic thermistor element to a pair of feeding terminals, leading out the leading part of the pair of feeding terminals from the side of the recessed part of a case and covering the open surface of the recessed part of the case by a lid body. SOLUTION: One side feeding terminal 15, a positive temperature characteristic element 14 and the other side feeding terminal 16 are installed into the recessed part 18 in that order from a partition wall 11a side so as to be electrically connected respectively to the electrodes 14a, 14b of the positive temperature characteristic thermistor 14. The leading parts 15b, 16b of the pair of feeding terminals 15, 16 are led out in the lateral direction from the side wall of the recessed part 18 through the cut-out parts 11b, 11c of the case 11, and the open surface of the recessed part 18 is covered with a lid body 12, and a radiating cylinder 13 is inserted through a nearly U-shaped opening 17 from the lower side of the case 11 in the state that a small opening is hardly formed in the inner wall. Therefore, heat transmitted to the case from the positive temperature characteristic thermistor element is hardly transmitted to the lid body but efficiently transmitted to the case.

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 for use in insecticides such as liquid type electronic mosquito traps, fragrances, etc., and more particularly to a positive temperature coefficient thermistor device which has high heat transfer efficiency and is easy to manufacture. It is a thing.

[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.

The structure of 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, an outer cylinder 1b, and a bottom plate 1c.
An integrally formed insulating case 1, a lid 2 that covers the upper opening surface of the insulating case 1, an eyelet 3, and a positive temperature coefficient thermistor element 4 having a cylindrical shape with electrodes formed on its upper and lower surfaces,
It is composed of 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 electrically 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. Further, a lid body 2 made of an insulating resin is fitted into the upper opening surface of the insulating case 1 and integrally fixed by an eyelet 3, and an air layer 8 is formed between the inner cylinder 1a and the eyelet 3 by a gap. Occurs.

[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, it is difficult to mold and fire, and warping is likely to occur, which requires post-processing such as polishing.

[0007] 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.

[0008] 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 transfers the heat generated by the positive temperature coefficient thermistor element to the heat radiating cylinder. It is to provide a characteristic thermistor device.

[0010]

To achieve the above object, in a positive temperature coefficient thermistor device of the present invention, a case having a substantially U-shaped opening and a recess formed in the vicinity of the U-shaped opening. A flat plate type positive temperature coefficient thermistor element having electrodes formed on both main surfaces, a pair of power supply terminals, a heat dissipation tube,
A lid, the heat dissipation cylinder is disposed inside the U-shaped opening, and one of the pair of power supply terminals has a substantially flat plate part and the other has a resilient contact part. A power feeding terminal, wherein the one power feeding terminal, the positive temperature coefficient thermistor element and the other power feeding terminal are housed in the recess of the case, the electrodes on both main surfaces of the positive temperature coefficient thermistor element, and the pair of power feeding terminals. And the lead-out portions of the pair of power supply terminals are drawn out from the side portions of the recess of the case, and the opening surface of the recess of the case is covered by the lid.

Further, the PTC thermistor element is in surface contact with the partition wall located between the substantially U-shaped opening and the recess or the bottom surface of the recess through the flat plate portion of the one power supply terminal. It is characterized by

Further, the lid body is made of a resin having a low heat conductivity, and has a substantially circular through hole corresponding to the substantially U-shaped opening of the case, and the heat dissipation tube is provided with the through hole. The lid is fixed to the case by being inserted and locked in the substantially U-shaped opening of the case and the through hole of the lid.

Since the heat transfer path includes the power supply terminal, the insulating case, and the heat dissipation tube, the heat generated by the PTC thermistor element can be efficiently used. An air layer having poor heat conduction is provided between the positive temperature coefficient thermistor element and the insulating case except for the substantially U-shaped opening side to prevent wasteful heat dissipation.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION One embodiment of the present invention will be described in detail with reference to FIG. However, in FIG.
The inner lid 20 will be described later. The PTC thermistor device includes a case 11, a lid 12, a heat radiating cylinder 13, electrodes 14a and 14b formed on both main surfaces, and a plate-shaped PTC thermistor element 14, and a pair of power supply terminals 15 and 16.

The case 11 is made of, for example, an insulative ceramic material such as alumina, and has an opening 17 having a substantially U-shaped cross section in which the heat radiating cylinder 13 can be press-fitted or inserted, and a vicinity of the opening 17. A recess 18 capable of accommodating the positive temperature coefficient thermistor element 14 and the pair of power supply terminals 15 and 16 is formed via the partition wall 11a. A protrusion 19 that restricts the movement of the positive temperature coefficient thermistor element 14 and one power supply terminal 15 is provided on the side wall of the recess 18. Furthermore, approximately U
The projection 1 for preventing the radiation tube 13 from coming off is provided in the character opening 17.
7a and 17a are formed. Furthermore, case 1
Notches 11b, 11c into which the lead-out portions 15b, 16b of the pair of power supply terminals 15, 16 can be inserted in the upper part of the side wall of 1.
Are formed.

The lid 12 is made of, for example, a resin having a low thermal conductivity such as polyphenylene sulfide, phenol, or nylon resin, or a ceramic material such as alumina, and has an opening surface of the recess 18 and an upper surface of the substantially U-shaped opening 17. To cover. The mounting bases 12a and 12a are provided on the upper surface of the substantially U-shaped opening 17 and have a substantially circular through hole 12c and project from the side of the case 11. The mounting bases 12a and 12a are provided. A notch 12b for mounting such as a through hole or a female screw is formed in 12a.

The heat radiating cylinder 13 is made of, for example, aluminum having a good thermal conductivity and has a cog shape with a collar 13a formed at one end, and its outer diameter portion is approximately U from below the case 11.
It can be mounted with almost no gap formed in the character-shaped opening 17 and the substantially circular through hole 12c.

The pair of power supply terminals 15 and 16 comprises one power supply terminal 15 and the other power supply terminal 16. One of the power supply terminals 15 is a terminal made of metal such as SUS (stainless steel) and has a positive temperature coefficient thermistor element 14 formed at one end side.
Of the flat plate portion 15a abutting against the electrode 14a and a lead-out portion 15b formed on the other end side, and a notch or slit or the like is provided between the flat plate portion 15a and the lead-out portion 15b in the width direction of the lead-out portion 15b. Narrow portion 15 to be formed
c is provided. The other power supply terminal 16 is a terminal made of metal such as SUS or phosphor bronze having elasticity,
Electrode 1 of PTC thermistor element 14 formed on one end side
4b, and a lead-out portion 16b formed on the other end side.

In the PTC thermistor device, one feeding terminal 15, the PTC thermistor element 14, and the other feeding terminal 16 are sequentially connected to the electrodes 14a and 14b of the PTC thermistor element 14 in the recess 18 from the partition wall 11a side. After being loaded as described above, the opening surface of the recess 18 is covered with the lid 12, and the heat dissipation cylinder 13 is inserted from below the case 11 into the substantially U-shaped opening 17 with almost no gap from the inner wall thereof. The upper end of the heat dissipation tube 13 on the side opposite to the flange 13a side is crimped. Then, the case 11 and the lid 12 are joined together using, for example, a heat-resistant silicone adhesive. At this time, the positive temperature coefficient thermistor element 14 and the other power supply terminal 16 are provided with the protrusion 1 provided in the recess 18.
The movement of the one power supply terminal 15 in the direction of the narrow portion 15c is restricted by 9 and the insulation state with the narrow portion 15c of the one power supply terminal 15 is maintained. The lead-out portions 15b and 16b of the pair of power supply terminals 15 and 16 are the case 11
It is pulled out laterally from the side wall of the recess 18 through the notches 11b and 11c. Further, the narrow portion 15c provided on one of the power supply terminals 15 is bent from the flat plate portion 15a, and is arranged at a position where it does not contact the inner wall surface of the recess 18.

In this positive temperature coefficient thermistor device, the positive temperature coefficient thermistor element 14 heats up at a constant temperature when the pair of power feeding terminals 15 and 16 are energized, and the heat is generated in the flat plate portion 15a of one power feeding terminal 15 and the case 11. The heat is conducted from the case 11 to the heat dissipation cylinder 13 via the partition wall 11a. At this time, the electrode 14a which is the main surface of the positive temperature coefficient thermistor element 14
Comes into surface contact with the partition wall 11a of the case 11 via the flat plate portion 15a, and heat is efficiently conducted to the case 11. Therefore, the heat from the PTC thermistor element 14 is efficiently conducted to the heat radiating cylinder 13, and the heat radiating cylinder 13 has good heat conduction, so that the temperature distribution of the heat radiating cylinder 13 becomes uniform.

The radiating cylinder 1 has a core (not shown) in which the insecticidal liquid has penetrated, which is inserted into the internal space of the radiating cylinder 1.
The insecticidal liquid is warmed by the heat of 3 and has a function of evaporating the insecticidal liquid from the core.

Next, another embodiment of the present invention will be described in detail with reference to FIG. However, the same parts as those in the above-described one embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The PTC thermistor device comprises a case 21, a lid 12, a heat dissipation tube 13, a PTC thermistor element 14, and a pair of power supply terminals 25 and 26.

The case 21 is made of, for example, an insulative ceramic material such as alumina, and has an opening 27 having a substantially U-shaped cross section in which the heat radiating cylinder 13 can be press-fitted or inserted, and the vicinity of the opening 27. A recess 28 that can accommodate the positive temperature coefficient thermistor element 14 and the pair of power supply terminals 25 and 26 is formed via the partition wall 21a. A protrusion 29 that restricts the movement of the positive temperature coefficient thermistor element 14 and one of the power supply terminals 25 is provided on the side wall of the recess 28. Further, protrusions 27a, 27a for preventing the heat radiation cylinder 13 from coming off are formed at the tip of the U-shaped opening 27. Furthermore,
A notch 21 into which the lead-out portions 25b, 26b of the pair of power supply terminals 25, 26 can be inserted in the upper side wall of the case 21.
b and 21c are formed.

The pair of power supply terminals 25, 26 comprises one power supply terminal 25 and the other power supply terminal 26. One of the power supply terminals 25 is a terminal made of metal such as SUS (stainless steel) and has a positive temperature coefficient thermistor element 14 formed at one end side.
Flat plate portion 25a that abuts on the electrode 14a of the above, and a lead-out portion 25 that is drawn out to the side portion of the case 11 formed on the other end side
b, and a narrow width portion 25c formed by a notch or a slit in the width direction of the lead portion 25b is provided between the flat plate portion 25a and the lead portion 25b.
The other power supply terminal 26 is a terminal made of metal such as SUS or phosphor bronze having elasticity, and has an elastic contact portion 26a elastically contacting the electrode 14b of the positive temperature coefficient thermistor element 14 formed at one end side and another elastic contact portion 26a at the other end side. It is composed of a drawer portion 26b that is drawn out to the side portion of the formed case 11.

In the PTC thermistor device, one feeding terminal 25, the PTC thermistor element 14, and the other feeding terminal 26 are electrically connected to the electrodes 14a and 14b of the PTC thermistor element 14 in the recess 28 in order from the bottom surface 21e. After being loaded, the opening surface of the concave portion 28 is covered with the lid body 12, and the heat radiating cylinder 13 is inserted from below the case 21 into the substantially U-shaped opening portion 27 with almost no gap from the inner wall thereof. The upper end of the heat radiating cylinder 13 on the side opposite to the flange 13a side is crimped. Then, the case 21 and the lid 12 are joined together by using, for example, a heat resistant silicone adhesive. At this time, the positive temperature coefficient thermistor element 14 and the other power supply terminal 26 are provided with the protrusion 2 provided in the recess 28.
The movement of the one power supply terminal 25 in the direction of the narrow width portion 25c is restricted by 9 and the insulation state with the narrow width portion 25c of the one power supply terminal 25 is maintained. Further, the lead-out portions 25b and 26b of the pair of power supply terminals 25 and 26 are the case 21
It is laterally pulled out from the side wall of the recess 28 through the notches 21b and 21c. Further, the narrow width portion 25c provided on one of the power supply terminals 25 is bent from the flat plate portion 25a, and is disposed at a position where it does not contact the inner wall surface of the recess 28.

In such a positive temperature coefficient thermistor device, the positive temperature coefficient thermistor element 14 generates constant temperature heat by energizing the pair of power feeding terminals 25 and 26, and the heat of the flat plate portion 25a of one power feeding terminal 25 and the case 21. The heat is conducted from the substantially U-shaped opening 27 of the case 21 to the heat dissipation cylinder 13 via the bottom surface 21e and the partition wall 21a. At this time, the electrode 14a, which is the main surface of the positive temperature coefficient thermistor element 14, makes surface contact with the bottom surface 21e of the case 21 through the flat plate portion 25a, and heat is efficiently conducted to the case 21. Therefore, the heat from the PTC thermistor element 14 is efficiently conducted to the heat radiating cylinder 13, and the heat radiating cylinder 13 has good heat conduction, so that the temperature distribution of the heat radiating cylinder 13 becomes uniform.

In the PTC thermistor heater device according to the present invention, when an overcurrent flows through the PTC thermistor element 14, the narrow portion 15 provided at one of the power supply terminals 15 and 25.
c and 25c have a fuse function capable of cutting off the current flowing through the positive temperature coefficient thermistor heater device by fusing. The narrow portions 15c and 25c are connected to one of the power supply terminals 1
However, it is also possible to provide the other power supply terminals 16 and 26.

Further, the recesses 18, 28 of the cases 11, 21
Is simply sealed by the lid 12, so that harmful substances, such as insecticidal liquid, that may interfere with the contact points between the positive temperature coefficient thermistor element 14 and the pair of power supply terminals 15 and 16 or the pair of power supply terminals 25 and 26, etc. Can be protected from steam etc.

Furthermore, the mounting base 12b itself is clamped, or the notch 12 provided in the base 12b.
The positive temperature coefficient thermistor device can be easily attached and fixed to the main body of the liquid type electronic mosquito trap or the like by screwing with c.

As shown in FIG. 1, a nonflammable insulator such as mica is provided between the cases 11 and 21 and the lid 12 of the above-described embodiment, and the opening surface of the recess 18 of the cases 11 and 21 is formed. It is preferable to provide an inner lid 20 for covering the. In this case, since the non-combustible insulator cases 11 and 21 and the inner lid 20 surround the positive temperature coefficient thermistor element 14, heat resistance is increased regardless of the material of the lid 12.

Although the cases 11 and 21 have been described by taking an insulator such as ceramic as an example of the material, the cases 11 and 21 are made of alumina porcelain having a higher thermal conductivity and a purity of 75% or more suitable for powder formability. More preferably.

Furthermore, the positive temperature coefficient thermistor element 14
And the flat plate portions 15a and 25a and the partition wall 11a of the case 11.
Alternatively, it is preferable to apply silicon grease or the like to the bottom surface 21e of the case 21. In this case, a slight air layer between each member is filled with silicon grease to further improve heat transfer.

As described above, the positive temperature coefficient thermistor heater device according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the gist thereof.

[0035]

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 polishing 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 heat dissipation tube, and the heat transfer path from the PTC thermistor element to the heat dissipation tube is short and there is no air layer, so thermal efficiency is good.

3. An air layer having poor heat conduction is provided between the positive temperature coefficient thermistor element and the insulating case except for the substantially U-shaped opening side to prevent wasteful heat dissipation.

4. The case and the lid can be easily and firmly fixed because the heat radiating cylinder is inserted and caulked while the U-shaped opening and the through hole are overlapped. Further, since the lid is made of resin having poor heat conduction, the heat transferred from the positive temperature coefficient thermistor element to the case is efficiently transferred to the case without being transferred to the lid.

[Brief description of drawings]

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

FIG. 2 is an exploded perspective view of a positive temperature coefficient thermistor device according to another embodiment of the present invention.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

 11, 21 Case 11a Partition wall 12 Lid body 13 Radiating tube 14 Positive temperature coefficient thermistor element 14a, 14b Electrode 17,27 U-shaped opening 18,28 Recess 21e Bottom surface

Claims (3)

[Claims] 1. A case having a substantially U-shaped opening and a recess formed in the vicinity of the U-shaped opening, a plate-shaped positive temperature coefficient thermistor element having electrodes formed on both main surfaces thereof, and a pair of A power supply terminal, a heat dissipation tube, and a lid, the heat dissipation tube is disposed inside the U-shaped opening, and one of the pair of power supply terminals has a substantially flat plate section. , The other is composed of a power supply terminal having an elastic contact portion, the one power supply terminal, the positive characteristic thermistor element and the other power supply terminal are housed in the recess of the case, and both main surfaces of the positive characteristic thermistor element The electrodes and the pair of power supply terminals are electrically connected to each other, and the lead-out portions of the pair of power supply terminals are drawn out from the side portions of the recess of the case, and the opening surface of the recess of the case is covered by the lid. Positive characteristic sir characterized by Star system. 2. The PTC thermistor element is in surface contact with a partition wall located between the substantially U-shaped opening and the recess or a bottom surface of the recess via the flat plate portion of the one power supply terminal. The positive temperature coefficient thermistor device according to claim 1, wherein: 3. The lid is made of a resin having a low thermal conductivity, has a substantially circular through hole corresponding to a substantially U-shaped opening of the case, and the heat dissipation cylinder is the case. 3. The positive temperature coefficient thermistor according to claim 1 or 2, wherein the lid is fixed to the case by being inserted and locked in the substantially U-shaped opening and the through hole of the lid. apparatus.