JPH0135571Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention relates to a starting/protection device for an electric compressor, and in particular is an improved storage case for an externally mounted starting/protection device that is attached to the surface of the compressor case. Regarding.

[Technical background of the invention]

Generally, a single-phase induction motor, which has a simple structure and is inexpensive, is used as the motor for a small electric compressor, but since it has no starting torque, a starting device is installed in the auxiliary winding 2 of the motor 1, as shown in Figure 1. This starting device connects a starting capacitor 4 in series to the auxiliary winding 2 via a positive temperature coefficient thermistor 3 which becomes a low resistance element only when starting at a low temperature. Further, in order to detect overcurrent and prevent burnout of the electric motor 1, a protection device made of a bimetal 6 having an internal heater 5 is connected between the electric motor 1 and the power source. In the figure, 7 is an operating capacitor for improving the power factor, and 8 is a main winding.

Since the electric motor 1 is built into the compressor, these starting devices and protection devices are usually mechanically and electrically attached to the surface of the compressor case via terminals.

Fig. 2 shows a conventional example of the mounting structure, in which the positive temperature coefficient thermistor 3 for starting and the bimetal 6 for protection are separated from each other by a cover 9 and a case 1.
0 and a common base 1 as shown in the diagram.
It is designed to be connected by 1. The base 11 is attached to the terminal 13 of the compressor so that the case 10 housing the PTC thermistor 3 stands vertically with respect to the mounting surface of the compressor case 12.
The case 10 is connected through the intervening. By connecting this case 10, the opening of the cover 9 containing the bimetal 6 fitted into the base 11 faces the mounting surface of the compressor case 12, and the internal bimetal 6 faces the front of the case 12. The base 11 is pressed against the case 12. Finally, the power supply and capacitors 4 and 7 are connected to the external circuit connection terminals 14 protruding from the cover 9 and the case 10 to complete the installation. One of the external circuit connection terminals 14 serves as a cover 9 holder. As a result, the bimetal 6 operates due to the heat from the compressor case 12 and the internal heater 5 generated by the current, and protects the electric motor 1. Also, the positive temperature coefficient thermistor 3 in contact with the outside air has a low resistance, and the electric motor 1 is activated. It's starting to start. Note that 15 in FIG. 2 is a spring-type terminal for fixing the disc-shaped positive temperature coefficient thermistor 3 within the case 10.

[Problems with background technology]

However, in the conventional starting/protection device described above, the positive temperature coefficient thermistor 3 for starting and the bimetal 6 for protection are housed in separate covers 9 and case 10, and furthermore, a Since the base 11 is required, there is a problem that it is large and expensive. Furthermore, when assembling the compressor to the compressor case, it requires troublesome work such as fitting the cover 9 to the base 11 and connecting the case 10 with the interposition of the base 11, resulting in poor workability.
Moreover, there was a drawback that the case 10 for the PTC thermistor 3 protruded largely from the surface of the compressor case 12 after assembly. In particular, when it comes to small electric compressors, taking refrigerators as an example, which are often used, in recent years there has been a demand for larger vegetable compartments and space-saving mechanical compartments. Due to the miniaturization and reduction in height, there is a need for smaller and space-saving starting/protection devices that are attached to the top or side of the compressor case, but the conventional starting/protection devices described above are unable to meet these demands. I couldn't do it.

[Purpose of invention]

This invention was made in consideration of the above circumstances, and its purpose is to obtain a starting/protection device for an electric compressor that can be downsized and is not bulky because it fits closely to the surface of the compressor case.

[Summary of the idea]

In order to achieve the above object, this invention includes a positive temperature coefficient thermistor for starting the motor on one side of the flat case, and a bimetal for protecting the motor separated from the positive temperature coefficient thermistor on the other side. , the flat case is removably attached to the compressor case in the center, and a connection terminal for electrically connecting the positive temperature coefficient thermistor and bimetal to the electric motor in the compressor case is integrated, and this connection is made. The present invention is characterized in that the flat case is configured to come into close contact with the compressor case surface through electrical connection of the terminals. This allows the starting/protection device to be attached to the compressor case without any unevenness, and prevents the compressor case from becoming taller or taking up a large space after attachment.

[Example of idea]

Hereinafter, a preferred embodiment of the electric compressor starting/protection device according to this invention will be described with reference to the accompanying drawings.

Figure 3 shows a conceptual diagram of this invention. A positive temperature coefficient thermistor 21 for starting and a bimetal 22 for protection are installed around the terminal 20 of the electric compressor case.
are arranged in parallel on the compressor case plane. As shown, the positive temperature coefficient thermistor 21 is oriented parallel to the compressor case surface, which is a plate surface thereof. The positive temperature coefficient thermistor 21 and the bimetal 22 are assembled in the same case 23. As a result, the starting/protecting device is integrated and can have a flat structure with little protrusion from the compressor case.

Figure 4 shows another conceptual diagram of this invention, and the difference from Figure 3 is that the positive characteristic thermistor 2
1 and the bimetal 22 are not arranged in a straight line on the compression case, but are arranged in a triangular shape with the terminal 20 as the apex, which has the advantage of preventing the device from becoming too long.

Figures 5 and 6 show an embodiment of this invention.

As shown in the figure, a flat case 23 is provided with its flat surface aligned with the protrusion of the terminal 20 and recessed in order to tightly fit into the surface of the compressor case 24 that includes the protruding terminal 20 in the center. This flat case 23 is divided into two parts along a flat plane. A disc-shaped positive temperature coefficient thermistor 21 for starting the electric motor is installed on one side of the case 23, with its plate surface oriented parallel to the flat surface of the case 23, and the top and bottom of the plate surface supported and fixed by spring terminals 25. It is. Further, on the other side of the case 23 opposite to the above-mentioned one side, a bimetal 22 for protecting the electric motor is fitted and installed apart from the positive temperature coefficient thermistor 21. The flat case 23 is detachably attached to the compressor case 24 at the center of the flat case 23, and is engaged with the terminal 20 of the compressor to be electrically connected to the electric motor inside the compressor case 24. A connection terminal 26 is incorporated therein. In this way, the positive temperature coefficient thermistor 21, the bimetal 22, and the connection terminal 26 are integrated in the flat case 23, and the connection terminal 26
The flat case 23 is configured to be brought into close contact with the surface of the compressor case 24 by electrical connection to the terminal 20 of the compressor. Note that 27 in the figure is an external circuit connection terminal.

The operation of this embodiment having the above configuration will be described.

First, the positive temperature coefficient thermistor 21, bimetal 22, and connection terminal 26 are fitted into one of the flat case 23 that is divided into two parts, and the other case is covered with a lid to integrate them into the case 23 for activation and protection. Form the device. Next, point the flat surface toward the compressor case 24 surface, and
When the protrusion and the recess of the flat surface are aligned and the two are fitted, the terminal 20 and the connecting terminal 26 automatically engage, and the two are electrically connected.
The flat case 23 is in close contact with the surface of the compressor case 24. Therefore, the starting/protection device can be attached and detached from the compressor case 24 surface with a single touch, and work efficiency during attachment is greatly improved. On the other hand, since the flat case 23 attached to the compressor case 24 surface is in close contact with the compressor case 24 surface, the temperature of the compressor case 24 is directly applied to the bimetal 24 on the other side of the case 23 in which the bimetal 22 is incorporated.
2, and the temperature of the compressor case 24 can be easily detected. Therefore, an internal heater for operating the bimetal 22 can be omitted. Furthermore, since the bimetal 22 and the positive temperature coefficient thermistor 21 are installed apart from each other, the heat generated by the positive coefficient thermistor is not transmitted to the bimetal, and malfunction of the bimetal can be effectively prevented.

On the other hand, since the flat case 23 is attached with its flat surface facing the compressor case 24 surface, the protrusion height from the compressor case 24 surface is reduced.
Therefore, as shown in FIG. 7, even if a flat case 23 incorporating a starting/protection device is attached to the top surface of the compressor case of the compressor 30 housed in the machine room 29 of the refrigerator 28, the compressor's low It is possible to increase the height and meet the demand for space saving.

[Effect of idea]

In summary, this invention provides the following excellent effects.

(1) Since the positive temperature coefficient thermistor, bimetal, and connection terminal for starting and protecting the motor are integrated into the flat case, the compressor case is much smaller than the conventional case in which these are separate parts. It becomes easy to attach to the surface, and the height of protrusion from the compressor case surface after attachment can be reduced. Therefore, the starting/protection device can be manufactured at low cost, and the compressor can be made smaller and space-saving.

(2) Since the flat case is attached closely to the compressor case surface, the compressor case temperature can be easily detected by the bimetal, so the internal heater for bimetal operation can be omitted, simplifying the structure. The transformation is measured.

(3) Since the bimetal and the PTC thermistor are installed apart from each other, malfunction of the bimetal due to heat generated by the PTC thermistor can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a starting/protection circuit diagram of a motor common to the conventional and this invention, Fig. 2 is a sectional view of an installed state showing an example of a conventional starting/protection device, and Figs. 3 and 4 explain this invention. FIG. 5 is a front sectional view showing a preferred embodiment of the starting/protection device according to this invention, FIG. 6 is a side sectional view of the same, and FIG. It is a perspective view seen from the back side of a refrigerator showing an example of application. In the figure, 1 is an electric motor, 3 and 21 are positive temperature coefficient thermistors, 6 and 22 are bimetals, 23 is a flat case, 24 is a compressor case, and 26 is a connection terminal.

Claims (1)

[Scope of utility model registration request] A flat case that is divided into at least two parts along the flat plane of the compressor case is divided into two spaces by a partition plate, and the plate surface is placed in one side of the partitioned space parallel to the flat plane of the flat case. At the same time, a positive temperature coefficient thermistor for starting the electric motor is installed in the space on the other side, and a bimetal for protecting the electric motor is installed in the space on the other side, and this bimetal and the positive coefficient thermistor are connected through a terminal of the compressor case. A connection terminal for electrically connecting to the electric motor in the compressor case is integrally incorporated, and a recess is formed in a portion of the flat case facing the terminal to fit with the terminal, and the flat case is A starting/protection device for an electric compressor, characterized in that it is configured so as to be able to come into close contact with the surface of a compressor case.