JP2522899Y2 - Positive characteristic thermistor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a PTC thermistor device used for a demagnetizing circuit of a television receiver.

BACKGROUND ART As shown in FIG. 6, a positive temperature coefficient thermistor device 101 used for a demagnetizing circuit of a television receiver includes, as shown in FIG.
A pair of spring terminal plates 103 and a common terminal plate 104 as shown in FIG. Positive characteristic thermistor element (hereinafter, referred to as PTC element) 107 and heater
PTC elements 108 are sandwiched respectively. Also, each terminal board
Lead legs 109 and 110 of 103 and 104 are drawn downward from holes 111 and 112 opened in the bottom of case 102.

This PTC thermistor device 101 is used, for example, in a degaussing circuit 113 as shown in FIG.
When the switch 14 is turned on, a current flows from the AC power supply 115 to the degaussing coil 116, and a magnetic flux is generated in the degaussing coil 116. At the same time, a current also flows through the current limiting PTC element 107, and the temperature of the PTC element 107 rises and the resistance value of the PTC element 107 increases, so that the current flowing to the degaussing coil 116 gradually decreases. The degaussing coil 116 is demagnetized. Also switch 1
When 14 is turned on, current also flows through the PTC element 108 for the heater connected to the bypass side, and the temperature of the PTC element 108 rises. Since the PTC elements 107 and 108 are thermally coupled to each other via the thermal coupling portion 106 of the common terminal plate 104, the PTC element 107 is
Heated up by element 108 and degaussing coil 1
Reduce the current flowing through 16.

[Problem to be Solved by the Invention] However, in such a PTC thermistor device, a hole opened in the bottom of the case (each terminal is so easily inserted as to allow the automatic machine to insert the lead foot of each terminal plate). A hole that is considerably larger than the cross section of the plate is opened.) The flux or the vapor of the flux may enter and cause deterioration of the internal PTC element. In the worst case, the PTC element may be broken. Can lead to

In this case, since the conventional positive temperature coefficient thermistor device did not have a fuse function, the fuse provided in the main body of a television receiver or the like was blown when the PTC element deteriorated and an overcurrent flowed.

If the fuse is repeatedly blown and replaced several times in this way, the fuse may eventually be replaced with a large capacity fuse, and eventually the fuse will not fulfill its original function, and will not be able to operate from the positive temperature coefficient thermistor device or television receiver. It could ignite and lead to fire.

The present invention has been made in view of the above-described drawbacks of the conventional example, and has as its object to provide a positive-characteristic thermistor device that can be used safely by providing the positive-characteristic thermistor device with a fuse function. Is to do.

[Means for Solving the Problems] The positive temperature coefficient thermistor device of the present invention accommodates a plurality of terminal plates in a case, pulls out the lead legs of each terminal plate out of the case, and sets a positive characteristic between adjacent terminal plates. In a PTC thermistor device having a thermistor element sandwiched therein, at least one of the terminal plates is provided with a narrow portion having a fuse function, and a heat-resistant reinforcing material made of a heat-resistant resin for reinforcing the strength of the narrow portion. Are insert-molded so as not to contact the narrow portion and are integrally attached to the terminal plate.

In a double-type positive temperature coefficient thermistor device in which a common terminal plate and a pair of spring terminal plates are placed in a case, and a PTC element is sandwiched between the common terminal plate and each spring terminal plate, the common terminal plate has a narrow portion. A heat-resistant reinforcing material may be provided.

[Operation] In the present invention, a narrow portion having a fuse function is provided on the terminal plate of the positive temperature coefficient thermistor device. Therefore, if an overcurrent flows due to deterioration of the PTC element or the like, the terminal plate becomes thin. The width section is melted, and the current flowing through the PTC element can be immediately cut off.

Therefore, it is possible to prevent the fuse on the main body side of the television receiver from being blown, and prevent a fire from occurring by replacing the fuse on the main body side of the television receiver with a large-capacity fuse as in the related art.

Also, despite the provision of the narrow part on the terminal board, the narrow part is reinforced with heat-resistant reinforcing material, so when installing the terminal board in the case or inserting the lead foot of the terminal board into the board For example, it is possible to prevent the narrow portion from being bent by a mechanical impact.

In particular, in a double-type PTC thermistor device using two PTC elements, if a narrow portion having a fuse function is provided on the common terminal plate, the narrow portion of the common terminal plate is blown when an abnormality occurs. The current of both PTC elements can be cut off at once. Further, since the narrow portion is reinforced by the heat-resistant reinforcing material, the thickness of the common terminal plate can be reduced, and the degree of thermal coupling between the PTC element for heater and the PTC element for current limiting can be increased.

Also, in the present invention, since the heat-resistant reinforcing material is attached to the terminal plate so as not to contact the narrow portion, the heat-resistant reinforcing material touches the narrow portion and the heat capacity of the narrow portion changes, It is possible to prevent the fusing characteristics of the narrow portion from changing.

Moreover, in the present invention, the heat-resistant reinforcing material is insert-molded with a heat-resistant resin and integrally attached to the terminal plate, so that the heat-resistant reinforcing material can be easily provided without applying a load to the narrow portion. In addition, when the heat-resistant reinforcing material is attached to the terminal board, there is no possibility that the narrow portion is bent or twisted by applying a load.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 shows a PTC thermistor device 1 according to an embodiment of the present invention.
FIG. 1 is a front view of the common terminal plate 2 and FIG. 2 is a front view of the common terminal plate 2 before the heat-resistant reinforcing member 3 is provided.

The common terminal plate 2 is separated from the flat thermal coupling portion 4 by a lead leg 5.
The base of the lead leg 5 is formed with a narrow portion 6 having a width (or cross-sectional area) determined so as to blow at a predetermined current value. As shown in FIG. 1, heat-resistant reinforcing members 3 are attached to the common terminal plate 2 from both sides of the common terminal plate 2 so as to surround the narrow portion 6. The heat-resistant reinforcing material 3 is formed of a thermosetting heat-resistant resin having a heat-resistant temperature higher than the heat-resistant temperature of the case 7, and the common terminal plate 2 as shown in FIG. 2 is integrally insert-molded. If the narrow portion 6 is in contact with another component, the fuse capacity of the narrow portion 6 varies, so that the heat-resistant reinforcing member 3 is provided so as not to contact the narrow portion 6. Further, when the common terminal plate 2 is inserted into the case 7, the narrow width portion 6 does not contact the case 7.

The common terminal plate 2 is accommodated in a central portion of an insulating case 7 formed of a heat-resistant resin, and spring terminal plates 8 are accommodated on both sides thereof. The lead leg 9 of the spring terminal plate 8 and the lead leg 5 of the common terminal plate 2 are inserted through holes 10 and 11 at the bottom of the case 7, respectively, and are drawn downward. In addition, if the heat-resistant reinforcing member 3 provided on the common terminal plate 2 has a cross-sectional dimension substantially equal to the size of the hole 11 through which the lead foot 5 is inserted, and is accommodated in the hole 11 of the case 7, The airtightness is improved, so that flux and the like hardly enter through the hole 11 of the case 7,
The deterioration and the like of the C elements 12 and 13 can be prevented, and the environmental resistance of the PTC thermistor device 1 is improved. Furthermore, heat-resistant reinforcing material 3
This prevents the narrow width portion 6 from coming into contact with the case 7. Between the thermal coupling part 4 of the common terminal plate 2 and the spring contact 14 of the spring terminal plate 8, a PTC element 12 for current limiting and a P
The TC elements 13 are sandwiched respectively. In order to reduce the gap between the holes 10 of the case 7 and to improve the hermeticity of the case 7, a reinforcing material may be provided on the spring terminal plate 8 as well.

Thus, for example, when the PTC elements 12 and 13 are deteriorated by chlorine gas or the like evaporating from the flux or the like and an overcurrent flows through the PTC elements 12 and 13, the narrow portion 6 of the common terminal plate 2 is quickly blown, and It is possible to prevent the elements 12 and 13 from firing or the fuse on the main body side of the television receiver from being blown. Moreover, since the narrow portion 6 is provided on the common terminal plate 2, even if any of the PTC elements 12 or 13 deteriorates, the narrow portion 6 is blown and the current of both PTC elements 12 and 13 can be cut off at once. , Increase safety.

Moreover, in the common terminal plate 2 before the provision of the heat-resistant reinforcing material as shown in FIG. 2, although the mechanical strength of the narrow portion 6 is extremely weak,
As shown in FIG. 1, since the periphery of the narrow width portion 6 is reinforced by being surrounded by the heat-resistant reinforcing material 3, the mechanical strength of the common terminal plate 2 is improved, and the common terminal plate 2 is The narrow width portion 6 is less likely to be bent due to mechanical impact when the lead terminal 5 of the common terminal board 2 is inserted into the substrate or when the lead leg 5 of the common terminal plate 2 is inserted into the substrate. Further, since the strength of the narrow portion 6 is increased by the heat-resistant reinforcing member 3, the thickness of the common terminal plate 2 can be reduced, and the heat of both the PTC elements 12, 13 via the thermal coupling portion 4 can be reduced. The coupling can be increased, and the PTC element 12 for current limitation can be efficiently heated by the PTC element 13 for the heater. Although not shown, a stopper function portion (such as a protrusion or a step portion) for positioning the common terminal plate in the case may be provided on the heat-resistant reinforcing material.

Also, in this embodiment, a window 15 is opened in the heat-resistant reinforcing material 3,
Since the narrow portion 6 is exposed from the window 15 and at least a part of the narrow portion 6 is disposed outside the case 7, it is easy to check whether there is a disconnection failure in the narrow portion 6 by an external check. be able to. In addition, since the lead legs 5 of the common terminal plate 2 are hardly bent by reinforcing with the heat-resistant reinforcing member 3, the lead pitch accuracy of each of the terminal plates 4, 8 is improved, and automatic insertion into the substrate is facilitated.

Various shapes are possible for the narrow portion and the heat-resistant reinforcing material. For example, as shown in FIG. 4, a square frame-shaped heat-resistant reinforcing material 18 may be insert-molded so as to surround a narrow portion 17 provided at the base of the lead foot 5 of the common terminal plate 16.

Also, the common terminal board 19 in FIG.
As shown in the figure, a cantilevered narrow portion 20 is provided at right angles to the lead foot 5, and heat-resistant reinforcing members 21 and 22 are insert-molded at both ends of the narrow portion 20 so that the narrow portion 20 is firmly attached to the thermal coupling portion 4. It is fixed. In this embodiment, the common terminal plate 19 is
The narrow part 20 is not exposed when it is placed inside, but the long narrow part 20
Can be provided.

[Effects of the Invention] In the present invention, the terminal plate of the positive temperature coefficient thermistor device is provided with a narrow portion having a fuse function. As a result, the narrow portion is melted and the current of the PTC element can be immediately cut off.

Therefore, it is possible to prevent the fuse on the main unit of the TV receiver from being blown due to the PTC element, and to prevent a fire by replacing the fuse of the TV receiver with a large-capacity fuse as before. Yes, safety is improved.

In addition, despite the provision of a narrow width part on the terminal board, it is reinforced by providing a heat-resistant reinforcing material on the narrow width part, so when incorporating the terminal board into the case, or by attaching the lead feet of the terminal board to the board When inserting, the narrow portion becomes difficult to bend due to mechanical impact. Further, by increasing the strength of the terminal plate by the heat-resistant reinforcing material, it is possible to improve the terminal pitch accuracy,
It is also suitable for automatic mounting.

In particular, in a double-type positive temperature coefficient thermistor device using two PTC elements, if a narrow portion is provided on the common terminal plate, the narrow portion is blown even if any PTC element is abnormal. As a result, the current of both PTC elements can be cut off at the same time, and safety is improved. Further, since the thickness of the common terminal plate can be reduced by reinforcing the narrow width portion with a heat-resistant reinforcing material, the thermal coupling between the PTC element for the heater and the PTC element for current limiting can be enhanced.

[Brief description of the drawings]

FIG. 1 is a front view of a common terminal plate according to an embodiment of the present invention, FIG. 2 is a front view of the common terminal plate before the heat-resistant reinforcing member is attached thereto, and FIG. FIG. 4 is a cross-sectional view of the device, FIG. 4 is a front view showing a common terminal plate of another embodiment of the present invention, and FIGS. 5 (a) and 5 (b) are front views showing a common terminal plate of still another embodiment of the present invention. FIG. 6 is a front view showing a common terminal plate before mounting a part and a heat-resistant reinforcing material, FIG. 6 is a cross-sectional view showing a conventional PTC thermistor device, FIG. FIG. 3 is a circuit diagram showing a degaussing circuit using the same positive temperature coefficient thermistor device. DESCRIPTION OF SYMBOLS 1 ... Positive characteristic thermistor device 2,16,19 ... Common terminal board 3,21,22 ... Heat-resistant reinforcing material 5 ... Lead foot 6,17,20 ... Narrow width part 7 ... Case 8 ... Spring Terminal board 9 Lead leg 12,13 Positive thermistor (PTC) element

Claims (2)

(57) [Scope of request for utility model registration] 1. A positive temperature coefficient thermistor device comprising a plurality of terminal plates housed in a case, a lead leg of each terminal plate being pulled out of the case, and a positive temperature coefficient thermistor element being sandwiched between adjacent terminal plates. In order to reinforce the strength of this narrow part, provide a narrow part with a fuse function on one of the terminal boards,
A positive temperature coefficient thermistor device, wherein a heat resistant reinforcing material made of a heat resistant resin is insert-molded so as not to contact a narrow portion and is integrally attached to a terminal plate. 2. A spring terminal plate is disposed opposite to both sides of a common terminal plate, and a positive temperature coefficient thermistor element is sandwiched between the common terminal plate and both spring terminal plates. The positive temperature coefficient thermistor device according to claim 1, wherein a heat-resistant reinforcing material is integrally attached to the common terminal plate near the narrow portion.