JP2522900Y2 - Positive characteristic thermistor device - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a PTC thermistor device in which a PTC thermistor element (hereinafter referred to as a PTC element) for current limiting or for a heater is housed in a case. . For example, it is used for a degaussing circuit of a television receiver or a motor starting circuit of a refrigerator or the like.

BACKGROUND ART (First Conventional Example) FIGS. 5 and 6 are a longitudinal sectional view and a plan sectional view of a conventional positive temperature coefficient thermistor device 51 used for a demagnetizing circuit or the like. In this conventional example, an insulating case made of heat-resistant resin
A pair of spring terminal plates 53, which are formed by pressing a metal plate material, are delivered in 52, and spring contacts cut and raised from the spring terminal plates 53
A PTC element 55 for current limitation is sandwiched between 54 and a spring contact 54 is pressed against an electrode 57 of the PTC element 55. The lead foot 56 extending integrally from the spring terminal plate 53 is
Is drawn out of the case 52 from a hole in the bottom surface of the. In order to prevent the spring terminal plate 53 from warping or deforming due to the spring force of the spring contact 54 and changing the holding force (spring pressure) of the PTC element 55 by the spring contact 54, each spring terminal plate 53 Is in surface contact with the inner wall surface of the case 52.

(Second Conventional Example) FIGS. 7 and 8 show a positive temperature coefficient thermistor device 58.
FIG. 6 is a vertical sectional view and a plan sectional view showing another conventional example. In this conventional example, a pair of spring terminal plates 53 having a spring contact 54 in a case 52, and a flat common terminal plate 59 disposed between the pair of spring terminal plates 53 are delivered to face each other, Current limiting PTC between each spring terminal plate 53 and common terminal plate 59
An element 55 and a PTC element 60 for a heater are sandwiched therebetween.
Even in this type of positive temperature coefficient thermistor device 58, each lead foot 56, 61 is pulled out of the case 52 from a hole in the bottom surface of the case 52, and each spring terminal plate 53 having spring contacts 54 at both ends is provided.
Is in surface contact with the inner wall surface of the case 52 to prevent warpage and deformation.

As described above, in the conventional PTC thermistor device, even if it is a single type (FIGS. 5 and 6) in which one PTC element and two spring terminal boards are incorporated, two PTC elements are used. Even in the double type (FIGS. 7 and 8) incorporating two spring terminal plates and a common terminal plate, the PTC element is elastically held between the spring terminal plates facing the inner wall surface of the case as described above. A spring contact is provided so that the holding force (spring pressure) of the PTC element does not change due to the terminal plate warping or deforming due to the spring force of the spring contact. The spring terminal plate is backed up by making surface contact with the inner wall surface of the case.

For this reason, in the conventional PTC thermistor device,
The heat generated from the PTC element is transmitted to the case through the spring contacts and the spring terminal plate, and the surface temperature of the case increases, which results in the case material being exposed to high temperatures for a long time, which deteriorates the case. It was easy. On the other hand, the temperature of the PTC element is increased by the amount of heat dissipated from the case through the spring terminal plate, and there is a problem that the stable current supplied to the PTC element increases.

(Third Conventional Example) On the other hand, in the positive temperature coefficient thermistor device disclosed in Japanese Utility Model Laid-Open No. 55-91102, a plurality of elastic projections provided partially on the terminal plate are brought into contact with the inner surface of the case. A gap is created between the terminal plate and the inner surface of the case, so that heat is hardly transmitted from the PTC element to the case.

However, in this conventional example, since a plurality of elastic projections are provided on the terminal plate, in the assembling process of the positive temperature coefficient thermistor device, the terminal plate before being incorporated is easily entangled with the elastic projections, so that it is difficult to handle. When inserting the terminal board into the case, the elastic protruding pieces are easily caught on the case,
It was difficult to assemble the PTC thermistor device.

Further, even after the assembling of the positive temperature coefficient thermistor device, since the elastic protrusion is only partially provided on the terminal plate, the terminal plate easily bends in the middle of the position where the elastic protrusion is provided, and the PTC The holding power of the element may be reduced.

[Problem to be Solved by the Invention] The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and its purpose is to reduce assemblability and warp the terminal plate. To provide a positive temperature coefficient thermistor device capable of suppressing the deterioration of the case material by reducing the surface temperature of the case while preventing a change in the spring pressure caused by the PTC element and reducing the stable current supplied to the PTC element. It is in.

[Means for Solving the Problems] The positive temperature coefficient thermistor element of the present invention includes two or more terminal plates in a case, and protrudes lead legs of each terminal plate out of the case. In a positive temperature coefficient thermistor device having a characteristic thermistor element interposed therebetween, a projection is provided on the inner wall surface of the case facing the terminal plate along upper and lower sides of the inner wall surface, and the inner wall surface of the case is opposed to the inner wall surface of the case via the projection. By contacting the terminal plate and the case inner wall surface, a space is formed between the terminal plate and the case inner wall surface.

[Operation] In the present invention, since the protrusion forms a space between the terminal plate and the inner wall surface of the case, the terminal plate and the case are thermally blocked by an air layer having high heat insulation. . For this reason, the case is prevented from being heated by the heat generated in the PTC element, the surface temperature of the case can be reduced, and the deterioration of the case material can be suppressed.

Further, since the heat generated in the PTC element is transmitted to the case surface and is not easily dissipated, it is possible to prevent the temperature of the PTC element from lowering due to the heat radiation, and to reduce the stable current supplied to the PTC element.

Moreover, since the protrusion for forming a space between the terminal plate and the case is provided on the case, not on the terminal plate,
In the process of assembling the PTC thermistor device, the terminal plates are not entangled when supplying the terminal plates, and the terminal plates are not caught on the case when the terminal plates are delivered to the case.

Furthermore, since the protrusions are provided on the inner wall surface of the case along the up and down directions, the protrusions can support the terminal portions along the up and down directions, and can reliably prevent the terminal plate from warping or deforming. Holding force of PTC element due to deformation (spring pressure)
Can be prevented from changing.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show a first embodiment of the present invention, which is a double type positive temperature coefficient thermistor device 11. The insulating case 1 in the shape of a square box made of heat-resistant resin is integrally shown in FIG. 1, but is actually composed of a bottom plate and a case body with an open bottom surface (or a cover body and a case body with an open top surface). ing. A common terminal plate 4 in the shape of a flat plate is accommodated in the center of the case 1. 1 in the case
The shape of the common terminal plate 4 has a size matching the inner surface of the case 1, and the outer peripheral edge of the common terminal plate 4 is in contact with the inner wall surface of the case 1. The lead feet 9 extending downward from the common terminal plate 4 are drawn out through holes (not shown) on the bottom surface of the case 1. Spring terminal plates 2 are arranged on both sides of the common terminal plate 4 so as to be opposed to the common terminal plate 4, respectively, and lead legs 8 extending downward from the spring terminal plate 2 are provided with holes (FIG. (Not shown). A spring contact 7 is cut and raised in the spring terminal plates 2 on both sides by press working, and a PTC element 5 for current limitation and a heater are provided between the spring contact plate 7 of the common terminal plate 4 and the spring contact 7 of the spring terminal plate 2. PTC elements 6 are press-fitted and elastically held. On the inner wall surface of the case 1, a rib-like projection 3 having a triangular cross section is projected over the upper and lower surfaces of the inner wall surface of the case, corresponding to the set position of the spring terminal plate 2. The projection 3 is formed when the case 1 is formed. Then, the spring terminal plate 2 is inserted into the case 1, and the projections 3 are brought into contact with both side portions of the spring terminal plate 2.
A surface contact between the spring terminal plate 2 and the case 1 is prevented, and a space 10 thicker than the spring terminal plate 2 is formed. The cross-sectional shape of the projection 3 can be variously, for example, a semicircular cross-section.

When electricity is supplied between the lead leg 9 of the common terminal plate 4 and the lead leg 8 of both spring terminal plates 2, both the PTC elements 5, 6 generate heat, and this heat is generated by the common terminal plate 4 and the spring terminal. Although transmitted to the plate 2, the common terminal plate 4 has only the outer peripheral edge thereof and the lead foot 9 in contact with the case 1. Since only the contact is made, and almost the entire spring terminal plate 2 is not in surface contact as in the first and second conventional examples, and the space 10 is separated,
The heat is hardly transmitted to the case 1 and the heat of the PTC elements 5 and 6 hardly raises the temperature of the case 1. Therefore, there is no fear of deterioration of the case material due to the temperature rise of the case 1,
The reliability of Case 1 is improved. On the other hand, since the heat of the PTC elements 5 and 6 is hard to be radiated from the case 1, the PTC element
The temperature drop of 5 and 6 can be prevented, and the PTC element 5 and
6 can be maintained at a required heat-generating temperature, and a stable current value can be reduced to save power. Moreover,
Although the space 10 is provided between the spring terminal plate 2 and the inner wall surface of the case 1, the protrusion 3 provided vertically on the inner wall surface of the case 1 is in contact with the spring terminal plate 2. The spring terminal plate 2 can be prevented from warping or deforming due to the spring force of the spring contact 7 (reaction force from the PTC elements 5 and 6),
The PTC elements 5, 6 can be stably held at a constant spring pressure. Further, since the projection 3 for forming the space 10 is provided not on the spring terminal plate 2 but on the case 1, the spring terminal plates are entangled with each other before assembling or when the spring terminal plate is inserted into the case. The terminal plate does not get caught on the case, and the assembling of the PTC thermistor device can be facilitated.

3 and 4 show a positive temperature coefficient thermistor device 12 according to a second embodiment of the present invention. This is because, in the single-type positive temperature coefficient thermistor device 12, the rib-shaped protrusions 3 formed on the inner wall surface of the case 1 are brought into contact with both side portions of the spring terminal plate 2, and the gap between the spring terminal plate 2 and the case 1 is formed. A space 10 is formed in the space.

[Effects of the Invention] According to the present invention, since the heat of the PTC element can be hardly transmitted to the case, an increase in the surface temperature of the case can be reduced, and deterioration of the case material can be prevented.
In addition, since the heat of the PTC element is less likely to be radiated from the case, the required heating temperature of the PTC element can be obtained with a smaller stable current, and the supplied stable current can be reduced.

In addition, in the method of assembling the PTC thermistor device, the terminal plates are not entangled when supplying the terminal plates, and the terminal plates are not caught on the case when the terminal plates are delivered to the case.

Furthermore, the terminal part can be supported in the vertical direction by the protruding part, and it is difficult for the terminal plate to be warped or deformed, so it is possible to prevent the fluctuation of the holding force of the PTC element due to the deformation of the terminal plate. The PTC element can be held with a stable holding force.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, FIG. 2 is a plan sectional view of the above embodiment, FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention, FIG. FIG. 5 is a plan view showing the first conventional example, FIG. 6 is a plan view showing the first conventional example, and FIG. 7 is a longitudinal sectional view showing the second conventional example. FIG. 8 is a plan sectional view of a conventional example of the above. DESCRIPTION OF SYMBOLS 1 ... Case 2 ... Spring terminal plate 3 ... Projection part 4 ... Common terminal plate 5, 6 ... Positive characteristic thermistor element 10 ... Space

Claims (1)

(57) [Scope of request for utility model registration] 1. A positive temperature coefficient thermistor device in which two or more terminal plates are accommodated in a case, lead legs of each terminal plate protrude out of the case, and a positive temperature coefficient thermistor element is sandwiched between adjacent terminal plates. By providing projections on the inner wall surface of the case facing the terminal plate along the top and bottom of the inner wall surface, and by contacting the terminal plate facing the inner wall surface of the case and the inner wall surface of the case via the projections. Wherein a space is formed between the terminal plate and the inner wall surface of the case.