JPS6114432B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides control for refrigerators, etc., which performs internal temperature control, defrost control, start-up control of compressor motors, etc. of refrigeration application equipment (hereinafter referred to as refrigerators, etc.) such as refrigerators and storage cases. It is related to the device.

Conventionally, the internal temperature control, defrost control, and start-up control of the compressor motor in refrigerators, etc., have been performed individually and unrelated, so each control requires an on/off switch that turns on and off a large current. I needed it. As a result, there are a large number of open/close switches, and their open/close operations are uncoordinated, causing many problems in terms of safety, failure rate, etc., and preventing this problem requires high costs.

The present invention aims to provide a control device that eliminates these drawbacks, and will be described in detail below with reference to the drawings.

In Figures 1 and 2, 1 is a power supply line connected to pole 2c of relay 2.
The normally closed fixed contact 2b to which the movable contact 2d connects when the coil 2e is de-energized is connected to one end of a well-known defrost device 3 such as a heater or solenoid valve coil, and when the coil 2e is energized, the movable contact 2b connects to the movable contact 2d. The normally open fixed contact 2a to which 2d is connected is connected to one end of the compressor motor 4.
The other power supply line 5 is connected to the other end of the compressor motor 4, and the pole 6c of the relay 6 is connected, and the normally closed contact 6b of this relay 6 is connected to the other end of the defroster device 3, The normally open contact 6a is connected to the starting coil 4a via the starting capacitor 7 of the compressor motor. In addition, 6e is the coil of relay 6, 4
b is the main winding of the compressor motor, and 4c is an overload protection device. Reference numeral 8 denotes a start-up detection element that detects the start-up of the compressor motor 4 using a start-up current or the like (for example, a current relay). This start-up detection element 8 outputs a relatively high potential (hereinafter referred to as H) signal at the time of start-up, and as shown in FIG. ing. 11 is an internal temperature detection element;
When the temperature inside the refrigerator reaches a temperature that requires cooling, an H signal is output, and when the temperature drops to a predetermined temperature, the H signal disappears (hereinafter referred to as the L signal).The output is divided into three directions, and one end is a NAND The other end of the element 10a goes into the NAND element 10b, and the other end goes into the timer element 12. This timer element 12 integrates the H signal time of the internal temperature detection element 11, and outputs the H signal when a predetermined time is reached. The H signal is reset by the L signal from the clear gate and changed to the L signal output. One end of the output passes through NOT element 9b and enters NAND element 10b, and the other end of the output enters NAND element 10c. 13
is a defrosting completion detection element, which is installed near the cooler for cooling the inside of the refrigerator (not shown), and outputs an H signal when defrosting is completed, and an L signal when the compressor is operated and cooled to a predetermined temperature.
It switches to a signal, and its output is NAND element 1
It is in 0c. Further, the output line of the NAND element 10b is connected to the relay 2 via the NOT table 9. Note that a NAND element outputs an L signal only when both input signals are H signals, and outputs an H signal for all other input signals, and a NOT element is an element that switches between an H signal and an L signal. . These are coil springs for relays 2 and 6 as shown in FIG.

The operation of the control device configured as described above will be explained next. During a power outage, that is, when no voltage is applied to the power lines 1 and 5, this device does not operate, and the movable contact 2d of the relay 2 is normally closed. The movable contact piece 6d of the relay 6 is connected to the normally closed contact 6b. Next, when a specified voltage is applied to the power supply lines 1 and 5, if the inside of the refrigerator is not cooled to the specified temperature, the internal temperature element 11 will output an H signal, and the timer element 12 will output an L signal, so NOT
The element 9b converts it into an H signal, and the NAND element 10
In addition to the H signal from the internal temperature detection element 11, two H signals are input to b, and as a result, an L signal is output, which becomes an H signal by NOT element 9c, which is applied to relay 2.
The coil 2e is energized, and the movable contact piece 2d is connected to the normally open contact 2a.

On the other hand, the activation detection element 8 also outputs an H signal due to the activation current caused by the closing of the contact 2a, and the NOT element 9a causes the activation detection element 8 to output an H signal.
As a result, the H signal and L signal are input to the NAND element 10a, and the output becomes the H signal, which energizes the coil 6e of the relay 6, and the movable contact 6d is connected to the normally open contact 6a, which is used for the compressor. A specified voltage is applied to the electric motor 4, and a voltage is also applied to the starting capacitor 7 and the starting winding 4a, so that the compressor electric motor 4 is started.

Next, when the compressor motor 4 starts, the starting current decreases and becomes the normal operating current, so the output of the starting detection element 8 switches to an L signal, and therefore both inputs to the NAND element 10a become H signals. The output becomes an L signal, the coil 6e of the relay 6 is deenergized, the movable contact 6d moves to the normally closed contact 6b, the starting winding circuit is deenergized, and the compressor motor 4 enters the normal operating state.

When the temperature inside the refrigerator falls to a predetermined temperature, the output of the temperature detection element 11 becomes an L signal, so the NAND element 1
At 0a, the L signal and H signal are input, and the output becomes the H signal, and the relay 6 is energized and the movable contact piece 6
d is connected to the normally open contact 6a. In addition, since the output from the timer element 12 is still an L signal,
It becomes an H signal by NOT element 9b and is input to NAND element 10b. Therefore, the L signal and H signal are input to the NAND element 10b, and its output becomes the H signal, but it is converted to an L signal by the NOT element 9c, the relay 2 is deenergized, and the movable contact 2d becomes the normally closed contact 2b. The compressor motor 4 is connected and the compressor motor 4 is stopped to stop cooling the inside of the refrigerator, and the defrost device 3 is also maintained in a de-energized state.

Next, when the compressor motor 4 operates for a predetermined time, that is, when the internal temperature detection element 11 outputs an H signal for a predetermined time, the timer element 12 outputs an H signal.
At this time, the internal temperature detection element 11 always outputs an H signal, so the NAND element 10b has an H signal and an L signal.
A signal is input and relay 2 is deenergized. Also,
The NAND element 10a sends the H signal from the internal temperature detection element 11 and the L signal from the activation detection element 8 to the NOT element 9.
Since the H signal converted in step a is input, the L signal is output and the relay 6 is also deenergized. Therefore, power line 5-
Pole 6c - Movable contact piece 6d - Normally closed contact 6b Defrost device 3
- Normally closed contact 2b - Movable contact piece 2d - Pole 2c - The path of power supply line 1 is configured and defrosting is started. At this time, the H signal of the timer element 12 is
Although the output from the defrosting completion detection element 13 is an L signal, the output of the NAND element 10c becomes an H signal, and the output of the timer element 12 is not cleared. Next, when defrosting is completed and the defrosting completion detection element 13 outputs an H signal, an L signal is input to the clear gate of the timer element 12, and the output of the timer element 12 is switched to an L signal. Then, two H signals are input to the NAND element 10b, and its output becomes an L signal, and the relay 2 is energized. This also energizes the main coil 4b of the compressor motor 4, and the starting current causes the starting detection element 8 to output an H signal, and the NAND element 10e
outputs an H signal and also energizes the relay 6, which is the same as the circuit at startup described above.

In addition, when the relays 2 and 6 are energized, the movable contact pieces 2d and 6d are deflected as shown by the broken line in FIG. The contacts move from side to side and slip, so brush them to prevent them from welding. but,
This phenomenon does not occur on the normally closed contacts 2b and 6b because the force of the spring 14 does not act very strongly. Therefore, by connecting the normally open contacts 2a and 6a to the compressor motor 4 through which a large current flows during startup,
Since the relays 2 and 6 operate each time the compressor motor 4 is energized or deenergized, the number of times the relays 2 and 6 are activated is very large, but the reliability of this control device can be made very high.

Since this invention is configured as described above, it is possible to control the internal temperature of the freezer, defrost control, and start-up control of the compressor motor using only two relays, and moreover, these controls are performed using the same signal source, so that each It is possible to obtain an inexpensive and highly reliable control device with coordinated operations.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an electric circuit diagram of a refrigerator or the like that employs the control device of the present invention, FIG. 2 is a block diagram showing the control part thereof, and FIG.
The figure shows the structure of a relay. In the figure, 2 and 6 are relays, 8 is a start detection element, 11 is an internal temperature detection element, 12 is a timer element, 13 is a defrost completion detection element, and 4 is a compressor motor.

Claims (1)

[Claims] 1 An element 8 that detects a starting current of a compressor motor in a refrigerant circuit for cooling the inside of the refrigerator when it exceeds a predetermined value, an element 11 that detects when the temperature inside the refrigerator reaches a predetermined temperature or more, and a defroster device 3. When defrosting of the internal cooler is completed, an element 13 that detects it, integrates the detection time by the internal temperature detecting element 11, and when that time reaches a predetermined time, it is set and the defrosting completion detecting element 13 detects it. The timer element 12 is reset in response to the detection of the internal temperature element 11 and the reset of the timer element 12, which closes the compressor motor energizing circuit and opens the defrost circuit. The relay 2 returns in response to at least one of the non-detection of the internal temperature detection element 11 and the setting of the timer element 12, and the detection of the compressor motor starting current detection element 8 and the detection of the internal temperature detection element 11. operates in response to at least one of the non-detections, opens the defrost circuit and closes the starting coil energizing circuit of the compressor motor;
A control device for a refrigerator, etc., characterized in that it is equipped with a relay 6 that returns to normal when the compressor motor starting current detecting element 8 detects no detection and when the internal temperature detecting element 11 detects.