JPH0132722Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an electrode plate with a terminal used in a positive temperature coefficient thermistor device used as a non-contact starter in a refrigerator compressor or the like.

Structure of conventional example and its problems As shown in FIGS. 1 and 2, this type of starter has a pair of terminals 2, 2 fixed through the side wall of a box 1 made of synthetic resin material, and A disc-shaped element 4 (hereinafter referred to as "element"), such as a positive temperature coefficient thermistor, is held between electrode plates 3, 3, which are fixed to electrode plates 2, 2 by spot welding or the like. Note that the element 4 includes an element body 4a and this element body 4.
Lower layer electrodes 4b, 4b in ohmic contact with a
Further, upper layer electrodes 4c, 4c for external connection with low contact resistance are formed thereon.

In the above configuration, the element 4 is
The element 4 is held and energized by contacting the upper layer electrodes 4c, 4c, and a wire connection receptacle (not shown) for external wiring is connected to the terminal 2, which is fixed integrally with the electrode plate 3. Since the terminals 2, 2 move within the play of the fixed part of the case 1 when they are press-fitted or removed during service, the electrode plates 3, 3 also slide in the same way, and their tips contact each other. The joints of the parts 3a, 3a and the element 4 will rub against each other, and the upper layer electrodes 4c, 4c of the element 4 with low contact resistance will be destroyed.
If it comes into contact with the lower layer electrodes 4b, 4b which have a high contact resistance underneath, resulting in poor contact, or if the damage is severe, the entire electrode part will be destroyed, making it impossible to establish continuity, or if it should not be brought into contact with the outside air in the first place. Otherwise, the lower electrode for ohmic contact would be exposed and sparks would occur when electricity was applied, which could seriously impair the reliability of the thermistor device. On the other hand, even if the element 4 starts thermal runaway due to application of an abnormally high voltage or due to its lifespan, and the element current increases at an accelerated rate, the terminals 2, 2 or the electrode plates 3, 3 will all receive a current that is too high for imitation strength. Because of the capacitance, the temperature rises (sometimes reaching about 1000° C.) until the element body 4a of the element 4 is completely destroyed, which could lead to a fire in the worst case.

Purpose of the invention The purpose of the invention is to improve the reliability of a non-contact starter and to ensure its safety even in the unlikely event of element destruction.

Structure of the invention To achieve this purpose, a narrow buffer part is provided in a part of the electrode plate, and this part absorbs the impulse transmitted from the terminal during external wiring, and the contact area between the element and the electrode plate is In addition to preventing friction, when the element current exceeds a certain level during thermal runaway during element destruction, the narrow portion is fused to detect thermal runaway of the element, thereby preventing abnormal temperature rises in the element.

DESCRIPTION OF EMBODIMENTS The present invention will be explained below with reference to an embodiment shown in FIGS. 3 and 4. A pair of terminals 6, 6 is fixed through the side wall of a box 5 made of synthetic resin material, and the same element 4 as in the conventional example is sandwiched between electrode plates 7, 7 fixed to the terminals 6, 6 by spot welding or the like. ing.
The electrode plate 7 has a contact portion 7a that comes into contact with the element 4 at its tip, a substantially V-shaped curved portion 7b that imparts elasticity to the contact portion 7a, and a terminal weld portion 7c, and this curved portion 7b. It is bent into a Z-shape between the terminal welding part 7c and the terminal welding part 7c, and has a narrow part 7d in the center thereof, which has a narrow plate width and melts at a current about 3 to 4 times the normal rush current to the thermistor device. There is.

The thermistor device assembled in such a configuration absorbs the impulse transmitted through the terminal 6 due to the attachment and detachment of the external wiring receptacle to the narrow portion 7 of the electrode plate 7.
Since it can be absorbed by the flexibility of d, the electrode plate contact part 7
Since there is no friction between the element 4 and the element 4, there is no exposure of the lower electrode 4b that impairs the life of the element 4, and there is no contact failure between the electrode plate 7 and the element 4, and the reliability of the thermistor device can be greatly improved. Furthermore, in the unlikely event that the element 4 starts thermal runaway due to the application of an abnormally high voltage or due to its lifespan, and even if the element current increases at an accelerated rate, the inflow current will be 3 to 4 times the normal inrush current of the element. The narrow portion 7d of the element 4 is melted off.
Abnormal temperature rise can be prevented.

Effects of the invention As is clear from the above explanation, the present invention has a contact part located at the tip, a curved part, and a terminal weld part that will melt when a certain amount of current flows, and have a narrow part that has a buffering effect. This device is equipped with an electrode plate that has an electric current, and a terminal that is fixed by a terminal weld.The narrow part of the electrode plate can absorb external impulses that are transmitted through the terminal, so there is no friction between the electrode plate and the element. Exposure of the lower electrode of the element and poor contact between the electrode plate and the element, which impair the life of the element, are eliminated, and the reliability of the thermistor device can be greatly improved. Furthermore, even if the element starts thermal runaway due to the application of an abnormally high voltage or due to the end of its life, and the element current increases at an accelerated rate, if the inflow current exceeds a certain level, the narrow part will be fused and the temperature of the element will rise abnormally. The effects are extremely large, such as being able to prevent this from happening.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional electrode plate with terminals;
Fig. 2 is a plan view showing the inside of the thermistor device incorporating the conventional example shown in Fig. 1, Fig. 3 is a perspective view of an electrode plate with terminals showing an embodiment of the present invention, and Fig. 4 is the present invention FIG. 2 is an internal plan view of a thermistor device incorporating an electrode plate with a terminal. 7a...Contact part, 7b...Curved part, 7c...
Terminal welding part, 7d... Narrow part, 7... Electrode plate, 6
...Terminal.

Claims (1)

[Scope of utility model registration request] An electrode plate having a contact part located at the tip, a curved part, a terminal weld part, and a narrow part that can be fused and has buffering properties when a current exceeding a certain level flows, and a terminal fixed at the terminal weld part. Equipped with an electrode plate with a terminal.