JPS6261226A - Overload protector for compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overload protection device for a compressor used in refrigeration equipment such as refrigerators, refrigerators, refrigerators, etc.

Conventional technology In recent years, overload protection devices for compressors have been developed to improve the utilization efficiency of compressor motors, as the operating conditions for the motors have become harsher. The role of the overload protection device is designed to provide 1/1 reliability and 1/1 functionality.

An example of the above-described conventional compressor overload protection device will be described below with reference to drawing F.

FIGS. 6, 7, 8, and 9 show an outline and wiring of a conventional compressor overload protection device. Figure 6 shows the installed state of the overload protection device of the compressor. It is attached in close contact with the compressor body (not shown). Reference numeral 6 is a starting device which is connected to the sealed terminal 6 of the shrinking machine and is housed in the protector cover 3 together with the overload protection device 1. 7°, 8.9 are terminals, and 10 is a starting device. The screw shaft, 11 is a lock nut, 3 and 12 are adhesives for fixing the screw shaft 10 and the lock nut 11. 13 is the main body case of the overload protection device 1, and the terminals 8, 9 and the screw 3 and 14 to which the shaft 10 is fixed by penetrating the hole are auxiliary heaters connected between the terminals 8 and 9 of iiJ and the screw,...]) between the bimetal 16 fixed to 10 and the main body case 130. It is located. Said bimetal 1
Contacts 3...-16 are provided at both ends of 6 and are connected through a built-in contact mechanism (not shown) of the terminal 7.9. 5 and 18 are protective covers attached to the main case 13. It is. Next, the 9th
To explain the electrical wiring using a diagram, in the diagram, 1
9 is a power supply; 2Q is a compressor motor; the overload protection device 1 and the motor 20 are connected in series to the power supply 19;

The operation of the compressor overload protection device configured as described above will be explained below. , Lt- When the supply power is applied to the electric motor 20 of the compressor and the compressor is operating, the overload protection device protects the electric motor 20 in addition to the heat transfer from the electric motor 20 through the compressor body (not shown). Due to the ohmic loss of the auxiliary heater 14 and the bimetal 15 due to the operating current to the auxiliary heater 14 and the bimetal 15, the temperature rises by -[1] due to self-heating. During operation of the EF compressor, if an overcurrent flows through the motor 20 or the motor 20 overheats, the overload protection device 1 shuts off the power supply 19 to the motor 20 by reversing the bimetal 150 to protect the motor 20 from overheating. After that, when it is gradually cooled by the ambient temperature and reaches the heating point temperature of the bimetal 16, the electric motor 20
When the power supply 19 is applied to the rotor of the motor 20 or the motor 20 is in a locked state due to some reason, the motor 20
An excessive current flows through the motor 2, and the bimetal 15 of the overload protection device 1 frequently repeats the reversal and return operations as the electric motor 2° warms the compressor body (not shown).

Conventionally, a compressor overload protection device has been configured as described above.

Problems to be Solved by the Invention However, in a configuration such as +811, overheating, overcurrent, and a load state of rotor locking occur due to overload operation of the motor 2° [~ bimetal 16 of overload protection device 1 is activated] Since it is necessary to set a certain period of time for the motor 2o to move backward when
The installation position is limited 3, 71. Due to the influence of the difference in ambient temperature and usage conditions on the protection characteristics, the set temperature range for the reversal and return temperature of the bimetal 15 of the overload protection device 1 must be set. This has the disadvantages of lowering the reliability of the bimetal 15 and hindering restartability when using a stopping characteristic thermistor type IJ l,'- as a starting device.

The present invention kl: ), in view of the problems mentioned above, provides an overload protection device for an AT compressor that can reliably protect the motor from overheating and facilitate restartability when the overload protection device is in operation. It is something to do.

Means for Solving the Problems In order to solve the above problems, the compressor overload protection device of the present invention incorporates a thermal element within the overload protection device, and energizes the thermal element when the bimetal is reversed. It has the following configuration.

Operation The present invention uses the thermal element provided in the overload protection device with the above-described configuration, so that when the overload protection device is activated due to overheating of the motor, the overload protection device is reliably kept warm by the heat generated by the thermal element. This will delay the return.

Embodiment Hereinafter, a compressor overload protection device 6' according to an embodiment of the present invention will be explained with reference to FIGS. 1 to 6.
Components that are the same as those of the prior art will be denoted by the same numerals and detailed explanations will be omitted. In the figure, 17 is +F, a thermal element with a characteristic, which is arranged inside the main body case 13 of the overload protection device 10, in contact with the ends -r7, 9, and outside the terminals 7.9 and 8, The thermal element 17 itself is electrically and thermally insulated 11 from the overload protection device 1 in appearance.
).

Reference numeral 17a denotes an Lt pole provided on the thermal element 17, from which the lead-in wire 1 is drawn out from the electrode 170 and connected to the terminal.
9 and spot 1 end C are connected to each other. 7a
, 9a are fixed contacts corresponding to the contacts 16 of the bimetal 16 inlaid on the terminals 7 and 9, respectively. The thermal element 17 is formed into a ring shape, and the 'electrode 17a is arranged so as to face a part of the inner surface thereof.

Next, the electrical wiring diagram will be explained using FIG. 5. In the figure, the lead-in wire 17b of the thermal element 17 is connected in parallel to the terminals 7 and 9 and the power supply 19.

The temperature of the thermal element 1 is set low so as not to prevent the bimetal 15 of the overload protection device 1 from returning to its original state.
... consideration has been given. That is, when the bimetal 15 is set to OFF and 0'CON at 1'20'C, the temperature is maintained at 66°C by the thermal element 17 without reaching the bimetal 15.

As described above, according to this embodiment, when the overload protection device 1 operates, the thermal element T-17 connected to both terminals 7 and 9 is energized, generates heat by itself, and stabilizes the time until the bimetal 16 returns. By delaying the time, the electric motor 2o can be reliably protected from overheating, and restarting can be advantageous.

As described above, the present invention provides an overload protection device with a thermal element, and when the overload protection device is operated, the thermal element heats the overload protection device.
Stables the time it takes for the overload protection device to recover from operation1.
5. Prolonging the heat dissipation time of the thermistor-type relay with positive characteristics can improve the restartability of the motor.5.

[Brief explanation of the drawing]

Fig. 1 is an f-plane view of the overload protection device for a compressor according to embodiments of the present invention, Fig. 2 is a cross-sectional view taken along line A-A' in Fig. 1, and Fig. 3 is a cross-sectional view of the FIG. 4 is a perspective view of the external appearance of a thermal element with positive characteristics, FIG. 6 is a wiring diagram of FIG. 1,
Figure 6 shows the installation of a conventional compressor overload protection device.
FIG. 7 is a flat curved view of the overload protection device C1, FIG. 8 is a sectional view taken along line BB' in FIG. 7, and FIG. 9 is a wiring diagram of FIG. 6. 1... Overload protection device, 1... thermal element P,
20...Electric motor. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
Overload protection device n-prc 1. Figure 2. ---PTc; Squirrel action poison 20- Electric tank Figure 5 Figure 6 Figure 7 Figure 8 Figure 90

Claims (1)

[Claims] An overload protection device for a compressor, wherein a thermal element is disposed in the overload protection device, and connected so that the thermal element is energized and generates heat when the overload protection device is operated.