JPH0235441B2 - SEITOKUSEISAAMISUTASOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positive characteristic thermistor device used as a non-contact starter to start the motor of a compressor such as a refrigerator, and one of its objects is to minimize the increase in power consumption. be.

Figure 1 shows the equivalent circuit of a general capacitor-start motor, where 1 is the motor main winding;
2 is a starting winding. 3 is a positive characteristic thermistor device, 4 is a starting capacitor (omitted for split-phase starting type motors), and A, B, C in the figure
is a portion led out to the outside of the motor case D as a terminal of the motor D, as shown in FIG. The present invention relates to a positive temperature coefficient thermistor device 3 connected to terminals B and C among these terminals A, B, and C. First, in order to provide a detailed description of an embodiment of the present invention, an example of the configuration of a positive temperature coefficient thermistor device will be described with reference to the drawings.

3 to 6, reference numerals 5 and 5' denote spring terminals made of phosphor bronze plates connected to the motor terminals, and these spring terminals 5 and 5' are the motor terminals B and 5', respectively.
It has fitting portions 5a, 5'a that fit with C, and joint portions 5b, 5'b with other conductive parts formed by bending extensions of the fitting portions.

Reference numerals 6 and 6' designate external wiring connection terminals made of brass plates, which include tab portions 6a and 6'a for coupling with receptacles of external wiring cords, and joint portions 6b of the extended tab portions with other conductive parts. ,6′ and
It has positioning bending parts 6c and 6'c.

Reference numerals 7 and 7' designate electrode plates made of, for example, SUS430 stainless steel plates, which sandwich the PTC thermistor 8, and only the surfaces that come into contact with the PTC thermistor element 8 are plated with silver. These electrode plates 7, 7' have elastic parts 7a, 7' that sandwich the positive temperature coefficient thermistor 8.
It consists of a joint part 7b, 7'b which is an extension of a part of this elastic part and is connected to another conductive part.

Reference numeral 9 denotes an insulating case, which includes grooves 9a, 9b, 9c into which the spring terminals 5, 5', terminals 6, 6', and electrode plates 7, 7' can be inserted and positioned, and a housing part 9d in which the PTC thermistor element 8 is housed. and projections 9e and 9f for fitting and fixing with the insulating cover 10. Here, one side 5 of the spring terminal and one side 6 of the external wiring connection terminal are connected to the respective joint portions 5b and 6.
After being fixed by spot welding or the like in step b, it is housed in the groove 9a of the insulating case 9. Also,
One of the remaining spring terminals 5, 5'5' and one of the electrode plates
7 on the non-plated surfaces of joint parts 5'b and 7b, respectively, and terminals 6 and 6' for external wiring connection.
The remaining one 6' of the electrode plates 7 and 7' is the non-plated surface of the joint parts 6'b and 7'b, respectively, and the remaining one 6' is fixed by spot welding, etc., and then the electrode plate 7, The silver-plated surfaces of the elastic parts 7a and 7'a of the positive temperature coefficient thermistor 8 are held in opposing contact with the respective electrode surfaces of the positive temperature coefficient thermistor 8, and the grooves 9b and 7'a of the insulating case are held.
It is stored in 9c. 10 is an insulating cover, which is connected to the insulating case 9 through protrusions 9c and 9d;
The spring terminals 5, 5', terminals 6, 6', electrode plates 7, 7', and positive temperature coefficient thermistor 8 are housed and fixed inside. Therefore, when attaching the positive temperature coefficient thermistor device with spring terminals configured in this manner to the motor terminals, the fitting portions 5a, 5'a of the spring terminals 5, 5' should be connected to the motor terminals B, C. All they have to do is fit.

In the positive temperature coefficient thermistor device having the above configuration, copper-based materials such as beryllium copper and phosphor bronze have conventionally been used as the electrode plates 7 and 7' that sandwich the positive temperature coefficient thermistor 8. When the motor is started, current flows through the auxiliary winding 2 and the PTC thermistor 8 generates heat, and because the conductivity of this heat is high, the amount of heat that escapes from the PTC thermistor 8 to the outside via the electrode plates 7 and 7' is Therefore, the amount of self-heating in the positive temperature coefficient thermistor 8 increases, resulting in high power consumption.

However, the invention was made to improve the above-mentioned drawbacks, and the electrode plates 7 and 7' are formed of a stainless steel material with low thermal conductivity instead of a copper-based material.
and elastic portions 7a, 7 in contact with the positive temperature coefficient thermistor 8.
A′ is plated with a material with low contact resistance, such as silver. Therefore, when the PTC thermistor has a high resistance, the amount of heat transferred from the PTC thermistor 8 through the electrode plates 7, 7' to the spring terminals 5, 5' or the terminals 6, 6' and escaping to the outside is reduced. By minimizing the contact resistance at the point of contact with the PTC thermistor 8, the PTC thermistor 8
It has become possible to reduce power consumption in (Experimental value: 30% to 35% compared to conventional copper-based materials)
It has become possible to reduce power consumption. ) Furthermore, only the surfaces of the electrode plates 7 and 7' that contact the positive temperature coefficient thermistor 8 are plated with silver to suppress contact resistance, and the back surfaces are left as raw materials, making it easier to connect them to the spring terminals 5' and 6'. Good spot weldability for fixing.

Further, it is possible to prevent the temperature of the insulating case, the insulating cover, etc. from increasing.

Furthermore, by welding the spring terminal, electrode plate, and terminal, it is possible to combine them within the same housing space, and each can be formed using the necessary material and shape, making it possible to integrate complex-shaped conductive terminal plates. It is not necessary to form the structure into a shape, and the ease of assembly is improved.

As is clear from the above description, the PTC thermistor device according to the present invention uses a metal material having a lower thermal conductivity than a copper-based material as the electrode plate holding the PTC thermistor, and the PTC thermistor and the first,
Since a silver plating layer is interposed between the second electrode plate and the PTC thermistor, the amount of heat escaping from the PTC thermistor to the outside is smaller than that of conventional copper-based materials used for the electrode plate. The power consumption is significantly reduced, and therefore the increase in power consumption, which was the biggest drawback when using a positive temperature coefficient thermistor device as a non-contact starter for a compressor motor in a refrigerator, can be minimized. The effects of its implementation are huge.

Further, since a metal material having a lower thermal conductivity than a copper-based material is used as the electrode plate, it is possible to prevent the temperature of the insulating case, the insulating cover, etc. from increasing. Since a silver plating layer is interposed between the positive temperature coefficient thermistor and the first and second electrode plates, it is possible to prevent the positive temperature coefficient thermistor from generating local heat, and the temperature at which the positive temperature coefficient thermistor goes into thermal runaway (positive When a characteristic thermistor reaches a certain temperature, it is destroyed and exhibits unstable characteristics.) This can improve reliability.

Furthermore, by electrically connecting the spring terminal, electrode plate, and terminal, it is possible to combine them within the same housing space, and the materials required for each
It is sufficient to form the conductive terminal plate in any shape, and there is no need to integrally form the conductive terminal plate in a complicated shape, which improves the ease of assembly.

[Brief explanation of drawings]

Fig. 1 is an equivalent circuit diagram for starting a motor, Fig. 2 is a side view showing the positions of motor terminals, and Figs. 3 to 6 show an embodiment of a positive temperature coefficient thermistor device with a spring terminal according to the present invention. Figure 3 is an exploded perspective view, Figure 4 is a cross-sectional view, Figure 5 is a terminal arrangement diagram,
FIG. 6 is an external view. 7, 7'... Electrode plate, 8... Positive characteristic thermistor.

Claims (1)

[Claims] 1 An insulating case and an insulating cover having insulating properties that house a positive temperature coefficient thermistor, first and second electrode plates made of a metal material having a lower thermal conductivity than a copper-based material, and a first electrode plate connected to a motor terminal. , a second spring terminal, and first and second terminals for external wiring connection, the first electrode plate and the second spring terminal, the first spring terminal and the first terminal, the electrically connecting the second electrode plate and the second terminal to form a contactless starter circuit for the motor;
The PTC thermistor is sandwiched between the first and second electrode plates, and the electrode plate and the PTC thermistor are housed in an internal space formed by the insulating case and the insulating cover, and The spring terminal and the first and second terminals are arranged at different positions on the wall formed by the insulating case and the insulating cover, and the positive temperature coefficient thermistor and the first and second electrode plates are arranged at different positions on the wall formed by the insulating case and the insulating cover. A positive temperature coefficient thermistor device with a silver plating layer interposed between the layers.