JPS6044688B2 - temperature control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature control device such as a constant temperature bath, and is particularly aimed at safely holding stored articles.

Normally, the electric compressor and internal heater that make up the refrigeration cycle are operated alternately by a temperature controller to control the temperature of the thermostat, but there are sufficient safety measures in case the temperature controller malfunctions. It has not been done yet.

The present invention has been made in view of the above points, and an embodiment shown in the drawings will be described below.

Reference numeral 1 denotes an electric compressor that constitutes a refrigeration cycle together with a cooler (not shown) installed in the refrigerator, 2 a heater for heating the refrigerator installed in the cooler, and 3 an electric motor that circulates cold air in the refrigerator. As for the blower, the electric compressor 1 is connected to a power source via a temperature regulator 4 and a normally closed contact 6 of a low temperature alarm relay 5, and the refrigerator heater 2 is connected to the temperature regulator 4 and a normally closed contact 6. The electric blower 3 is further connected to a power source via a door switch 7.

Reference numeral 8 denotes an alarm safety device having an upper limit contact 9 and a lower limit contact 10 that turn on and off at an upper limit temperature that is sufficiently higher than the set temperature of the temperature controller 4 and a lower limit temperature that is sufficiently lower than the set temperature of the temperature controller 4;
0 is connected to the relay coil 11 of the low temperature alarm relay 5, and the upper limit contact 9 is connected to the relay coil 13 of the high temperature alarm relay 12.

The high temperature alarm relay 12 has a first normally open contact 14 connected in parallel to the normally open contacts 6 of the temperature controller 4 and the low temperature alarm relay 5, and a relay coil 17 of the self-holding relay 16 via a reset switch 15. It has a second normally open contact 18 connected in series with. Further, the self-holding relay 16 has a self-holding contact 19 and a relay contact 20, and an alarm device 21 such as an alarm buzzer or an alarm lamp is connected to the relay contact. Furthermore, the normally open contact 22 of the low temperature alarm relay 5 is connected to the high temperature alarm relay 12.
It is connected in parallel relationship with the second normally open contact 18 of. The operation in the above configuration will be explained. If you set the temperature regulator 4 to maintain the internal temperature at 5°C ± 1 (4 to 6°C) during pull-down, this contact will turn OFF.
I'm doing N.

Also, the upper limit of the temperature inside the refrigerator is 7°C, and the lower limit is 3°C.
If the alarm and safety device 8 are set so as to sandwich the set temperature of the temperature controller 4 at 5°C, for example, if the temperature is 30°C during pull-down, the upper limit temperature 9 of the alarm and safety device 8 will be higher than 7°C, so the ON1 lower limit will be set. Contact 10 is OF because the temperature has not dropped to 3℃.
I'm doing F. Therefore, the relay coil 11 of the low temperature alarm relay 5 is de-energized and its normally closed contact 6 is ON1, and the relay coil 13 of the high temperature alarm relay 12 is energized and the first normally open contact 14 and the second normally open contact 18 are turned on. Both are 0N.

For this purpose, the electric compressor 1 and the electric blower 3 are activated, and the temperature inside the refrigerator gradually decreases from 30°C. At the same time, the relay coil 17 of the self-holding relay 16 is also excited by turning on the second normally open contact 18, and the self-holding relay 16 is energized. Both the holding contact 19 and the relay contact 20 are turned on to activate the alarm 21. The internal temperature is 3
When the temperature drops from L°C to 6°C via 7°C, the upper limit contact 9 of the alarm safety device 8 turns OFF, and the relay coil 13 of the high temperature alarm relay 12 becomes de-energized, causing the first normally open contact 14 and the second
Both normally open contacts 18 are turned off. However, the normally closed contact 6 of the low temperature alarm relay 5 and the temperature regulator 4 are both ON.
Since the electric compressor 1 is in this state, the electric compressor 1 continues to operate, and since the self-holding relay 16 is also kept in the excited state by the self-holding contact 19, the alarm 21 also continues to operate. When the temperature inside the refrigerator further drops from 6°C to 4°C, the temperature controller 4
is turned off, the electric compressor 1 stops operating, and the refrigerator interior heater 2 is energized to defrost the cooler, and the interior temperature rises rapidly, and when it reaches 6°C, the temperature controller 4 is turned off. is turned on and the electric compressor 1 starts operating again.

On the other hand, the user checks the thermometer and the self-recording temperature recorder built into the alarm/safety device 8 to see that the temperature inside the refrigerator is 5°C ± 1°C, which is indicated by A in Figure 2.
After confirming that the alarm is controlled within the above range, when the reset switch 15 is pressed, the self-holding relay 16 is de-energized and the alarm 21 stops operating.

In this state, if the user opens the door and introduces a large amount of high-temperature heat load (stored material), the internal temperature will rise to 7°C or higher, the electric compressor 1 will operate, and the upper limit contact 9 of the alarm safety device 8 will be activated. is turned on and the alarm 21 is activated again.

When the temperature inside the refrigerator reaches the temperature range shown in Figure 2 A, the reset switch 15 is pressed to stop the alarm 21 from operating. Therefore, if an unexpected failure such as disconnection of the platinum resistance temperature detector of the temperature regulator 4 occurs, the contacts of the temperature regulator 4 will be turned OFF.
The internal temperature of the refrigerator, which remains at 5°C, rises due to the heat generated by the energization of the internal heating heater 2, exceeding 6°C and reaching 7°C.

When the temperature reaches 7°C, the upper limit contact 9 of the alarm safety device 8 is turned on to warn of high temperature.The first normally open contact 14 of the relay 12 is turned on to operate the electric compressor 1, and the second normally open contact 18 is turned on.
This activates the alarm 21 via the self-holding relay 16 to notify the user of the malfunction.

On the other hand, when the internal temperature drops from 7°C to 6°C, the upper limit contact 9 of the alarm safety device 8 turns OFF, and the internal heater 2 turns off again.
turns ON, and when the temperature reaches 7°C, the upper limit contact 9 turns ON.
The cycle in which the electric compressor 1 operates is repeated, and the temperature inside the refrigerator is maintained within the range shown in FIG. Next, if the contacts of the temperature regulator 4 remain in the ON state for some reason,
Electric compressor 1 is in continuous operation and the temperature inside the refrigerator is 5°C.
The temperature rises from 4°C to 3°C. When the temperature reaches 3℃, the lower limit contact 10 of the alarm safety device 8 turns ON and the low temperature alarm relay is activated.
Excite the relay coil 11 of 5 and turn off the normally closed contact 6.
to turn on the normally open contact 22.

As a result, the electric compressor 1 stops operating, and the internal heater 2 is energized to generate heat, raising the internal temperature from 3°C to 4°C. During this time, the self-holding relay 16 is connected to the normally open contact 22.
is excited by turning ON, and activates the alarm 21 to notify the user of the malfunction. When the temperature inside the refrigerator reaches 3°C to 4°C, the lower limit contact 10 of the alarm safety device 8 turns OFF, the low temperature alarm relay 5 becomes de-energized, and the normally closed contact 6 turns 0N.

As a result, the electric compressor 1 starts operating again, and the temperature inside the refrigerator is maintained within the range C in FIG. To summarize the above operation, normally the electric compressor 1 and the heater 2 for heating the inside of the refrigerator are operated alternately by turning ON10FF of the temperature controller 4 to maintain the inside temperature in the range of 4°C to 6°C. If the controller 4 malfunctions and turns off, the upper limit contact 9 of the alarm safety device 8 operates the electric compressor 1 and the heater 2 alternately to keep the temperature inside the refrigerator at 6°C to 7°C. If the temperature is maintained within the range and turns ON due to a malfunction, the lower limit contact 10 of the alarm safety device 8 operates the electric compressor 1 and the heater 2 alternately to lower the temperature inside the refrigerator to 3°C to 4°C. Keep it within range.

And ON due to failure. ．． In either case, the alarm 21 is activated to notify the user of the malfunction. Therefore, even when the temperature regulator 4 is out of order, the temperature inside the refrigerator can be controlled within a range close to the set temperature (3° C. to 7° C.). As described above, the present invention provides an electric compressor, an internal heater, an alarm, a temperature controller, and an alarm safety system having an upper limit temperature sufficiently higher than the set temperature of the temperature controller and a lower limit temperature sufficiently lower than the set temperature of the temperature controller. Normally, the electric compressor and the heater for heating the inside of the refrigerator are operated alternately by the temperature controller to adjust the temperature inside the refrigerator, and in the event of a failure of the temperature controller, the safety device is used to adjust the temperature. Regardless of the container, the heater is selectively activated at the lower temperature limit, the compressor is selectively activated at the upper temperature limit, and the alarm is activated, so the temperature of stored items can be controlled safely and at a temperature close to the upper or lower limit. If this happens, an alarm can be used to notify the user of the failure as soon as possible, allowing the user to use the stored items immediately.

Additionally, the alarm is activated even if there is a gas leak in the refrigeration cycle or the heater is insulated, allowing for safer and more reliable temperature control.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram of a temperature control device according to the present invention, and FIG. 2 is a temperature control characteristic diagram. 1...Electric compressor, 2...Interior heater, 4...Temperature controller, 8...Alarm safety device, 5...・Low temperature alarm relay, 12...
・High temperature alarm relay, 16... Self-holding relay, 21...
...Alarm.

Claims (1)

[Claims] 1 Equipped with an electric compressor, an internal heater, an alarm, a temperature controller, and an alarm safety device having an upper limit temperature sufficiently higher and a lower limit temperature sufficiently lower than the set temperature of the temperature controller, which constitute the refrigeration cycle, The temperature controller alternately operates the electric compressor and the heater to adjust the temperature inside the refrigerator, and in the event of a malfunction of the temperature controller, the safety device operates regardless of the temperature controller. A temperature control device that selectively operates the heater at the lower limit temperature, selectively operates the electric compressor at the upper limit temperature, and operates an alarm.