JPH0534520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a refrigerator using a compressor having a built-in pump for supplying lubricating oil to bearings and the like.

As mentioned above, some compressors used in refrigerators have a built-in pump that supplies lubricating oil to the bearings for the purpose of lubricating the bearings. In this case, if the pressure for supplying lubricating oil (hereinafter referred to as "hydraulic pressure") drops below a predetermined value, the intended lubrication effect may not be achieved sufficiently, and in extreme cases, damage to the bearing may occur. This may lead to burnout. For this reason, a hydraulic protection switch is provided to stop the compressor when the hydraulic pressure drops and prevent the bearing from burning out. This switch is configured to issue a command to stop the compressor when the oil pressure falls below a predetermined value for a predetermined period of time or more. 1st
The figure shows an example of a hydraulic protection device in a conventional refrigerator control device.
When this is applied, the control device 5 starts operating, and normally the refrigeration operation instruction device 6 issues an operation command to the compressor 1. The high-temperature, high-pressure refrigerant gas compressed by the compressor 1 radiates heat in the condenser 2, condenses and liquefies, and reaches the expansion device 3. The depressurized refrigerant enters the evaporator 4, absorbs heat from the surroundings, evaporates and vaporizes, and returns to the compressor 1, completing the refrigeration cycle. Here, the oil pressure generated by the operation of the compressor 1 is detected by the oil pressure detection device 8, and is transmitted to the oil pressure abnormality determination device 7 to determine whether it matches the abnormal condition specified by the oil pressure abnormality condition setting device 11. For example, it is determined whether or not an abnormality is recognized in the oil pressure based on whether operation with oil pressure below a predetermined value has been continued for a predetermined period of time. If it is determined that the refrigeration operation is normal, the refrigeration operation instruction device 6 does not issue a stop command to the refrigeration machine, and the operation continues as it is. On the other hand, if it is determined that there is an abnormality, the refrigeration operation instruction device 6 issues a command to stop the operation of the refrigerator, and the compressor 1 stops its operation. The refrigerating operation is restarted by turning on the reset switch 9.

FIG. 2 shows an example of an internal wiring diagram of a hydraulic protection switch, in which terminals 12 and 13 are connected to a circuit that drives a compressor, and terminals 14 and 15 are connected to a power source. The contact 18 is a contact that opens when the oil pressure is high, and closes when the oil pressure is low, and energizes the heater 17. When this low oil pressure state continues and a predetermined period of time has elapsed, the contact 16 is opened by the heat of the heater 17, and when the contact 16 is opened, the circuit that drives the compressor is cut off and the compressor is stopped. If the oil pressure rises above a predetermined value before the contact 16 opens, the contact 18 will open, and the power supply to the heater 17 will be stopped, the contact 16 will not open, and the compressor will not operate. will continue.

In the hydraulic protection device described above, even if there is an abnormality in the hydraulic pressure detection device, for example, the contact 18 of the hydraulic protection switch is open while the compressor is stopped in the wiring diagram shown in FIG. Since it does not prevent the protection device from operating, the problem is that it is not discovered and the protection device does not fulfill its role, leading to trouble.

The present invention has been proposed in view of the above-mentioned points, and an object of the present invention is to provide a control device for a refrigerator that allows easy failure diagnosis.

The present invention provides a hydraulic pressure detection means for a compressor, and when the pressure detected by the hydraulic pressure detection means during driving of the compressor continues to be lower than a predetermined value for a predetermined period of time, a command to stop operation is issued to the compressor. In a control device for a refrigerator equipped with a hydraulic protection device comprising a hydraulic pressure abnormality determination means, when it is determined that the hydraulic pressure detected by the hydraulic pressure detection means exceeds a predetermined value during a predetermined time while the compressor is stopped. , the gist of which is a control device for a refrigerator, characterized in that it is provided with a determining means for determining that the hydraulic pressure detecting means is abnormal, and a means for displaying an abnormality when the abnormality is determined, If a hydraulic pressure higher than a predetermined value is detected when there is no possibility that the hydraulic pressure is It can be displayed. Therefore, by early detection of failure, the hydraulic protection function can be restored and accidents can be prevented.

The present invention will be explained below based on examples.

In Figure 3, 1 is a compressor, 2 is a condenser, 3
Reference numeral 4 indicates a throttle device, and 4 an evaporator, which constitute a refrigeration cycle.

20 is a power supply, 21 is a control device and oil pressure detection device 2
2. A hydraulic pressure detection device abnormal condition determination device 23 that determines whether the set abnormal condition is met; a hydraulic pressure detection device abnormal condition setting device 24 that sets the above abnormal condition; and a hydraulic pressure detection device abnormal condition setting device 24 that determines whether the set abnormal condition is met a hydraulic abnormality determination device 25 for determining the hydraulic abnormality condition; a hydraulic abnormality condition setting device 26 for setting the hydraulic abnormality condition;
Reset switch 27, refrigeration operation instruction device 28,
It is comprised of an abnormality display device 29 that displays an abnormality when the oil pressure detection device 22 has an abnormality.

Next, the operation will be explained based on the flow chart shown in FIG.

When the power supply 20 is applied to the control device 21, the control device 21 starts operating and first takes in external input. One of these external inputs is the oil pressure detection device 22. Further, in the control device 21, a hydraulic pressure detection device abnormality condition setting device 24 is provided.
The oil pressure detected by the oil pressure detection device 22 meets the abnormal conditions set by the oil pressure detection device abnormal condition setting device 24, such as "the oil pressure must not exceed a predetermined value immediately after power is turned on." The oil pressure detection device abnormal state determination device 23 determines whether this is the case.
It is judged by. If it is determined that the oil pressure detection device 22 is abnormal, that is, if "the oil pressure detection device 22 detects that the oil pressure has already exceeded a predetermined value immediately after the power is turned on," this oil pressure detection The device abnormal state determination device 23 instructs the display device 29 to indicate that there is an abnormality. After the abnormality is displayed and when the oil pressure detection device 22 is determined to be normal, the refrigeration operation instruction device 28 and the oil pressure abnormality determination device 25 operate normally.

According to the command from the refrigeration operation instruction device 28, the compressor 1
When the system starts operating, the high temperature and high pressure refrigerant gas compressed by the compressor 1 radiates heat in the condenser 2.
It is condensed and liquefied and reaches the expansion device 3. The depressurized refrigerant enters the evaporator 4, absorbs heat from the surroundings, evaporates and vaporizes, and returns to the compressor 1, completing the refrigerant cycle. When the cooling progresses and the object to be cooled is cooled to a predetermined temperature, the refrigeration operation instruction device 28 issues a stop command to the compressor 1, and the compressor 1 stops its operation. When the temperature of the object to be cooled rises again, the refrigeration operation instruction device 28 instructs the compressor 1 to operate again, and thereafter repeats the above operation.

During this period, the hydraulic pressure is detected by the hydraulic pressure detection device 22.
The hydraulic pressure is detected by the oil pressure detection device abnormal state determination device 23, which determines whether it is normal or not, and then inputted to the hydraulic pressure abnormality determination device 25. Here, the hydraulic pressure is determined depending on whether the abnormal conditions set in the hydraulic abnormal condition setting device 26 are met, for example, whether the compressor 1 is in operation and continues to operate at a hydraulic pressure below a predetermined value for a predetermined time. Determine whether any abnormalities are observed. If it is determined to be normal, the refrigeration operation instruction device 28 continues the operation without issuing a stop command to the refrigeration system. If it is determined that there is an abnormality, the refrigeration operation instruction device 28 issues a stop command to the refrigeration system, and the compressor 1 stops its operation. To restart refrigeration operation, press reset switch 27.
This is done by inputting.

In addition, during a predetermined period of time when the compressor 1 is stopped, whether or not the oil pressure detected by the oil pressure detection device 22 matches the abnormal condition set in the oil pressure detection device abnormal condition setting device 24, for example, “compressor 1
Each time the compressor 1 starts or stops, the oil pressure detection device abnormal state determination device 23 determines whether the condition "the oil pressure does not exceed a predetermined value after a predetermined period of time after the compressor 1 has stopped" is determined to be abnormal. case,
A command is given to the display device 29 to display that there is an abnormality.

As is clear from the above, by using the above control device, even if there is an abnormality in the oil pressure detection device 22, for example, in the case of a failure in setting value adjustment or a failure, the failure does not interfere with normal operation. without being discovered by conventional methods.
As a result, there was a problem that it could not fulfill its role as a hydraulic protection device, but this problem has been resolved, and failures can be discovered in advance, and the hydraulic protection function can be restored through advance repair and adjustment. This makes it possible to prevent a major problem, that is, a seizure accident due to insufficient lubrication of the compressor.

In the above embodiment, when the oil pressure detection device is determined to be abnormal, only an abnormality display is performed, but the refrigeration operation may also be stopped, or both the abnormality display and the refrigeration operation stop may be performed. You may do so. Furthermore, the refrigeration operation may be stopped only immediately after the power is turned on.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the conventional one, Fig. 2 is an internal wiring diagram of the hydraulic protection switch, Fig. 3 is a configuration diagram showing an embodiment of the present invention, and Fig. 4 is a flowchart showing the operating state. be. 1... Compressor, 2... Condenser, 3... Throttle device, 4...
Evaporator, 20... Power supply, 21... Control device, 22... Oil pressure detection device, 23... Oil pressure detection device abnormal state determination device, 24... Oil pressure detection device abnormal condition setting device, 25
... Hydraulic abnormality determination device, 26... Hydraulic abnormality condition setting device, 27... Reset switch, 28... Refrigeration operation instruction device, 29... Display device.

Claims (1)

[Claims] 1 Hydraulic pressure detection means of the compressor, and hydraulic abnormality determination that issues an operation stop command to the compressor when the pressure detected by the hydraulic pressure detection means during driving of the compressor continues to be lower than a predetermined value for a predetermined period of time. In a control device for a refrigerator equipped with a hydraulic protection device comprising means, when it is determined that the hydraulic pressure detected by the hydraulic pressure detection means exceeds a predetermined value during a predetermined time while the compressor is stopped, the hydraulic pressure 1. A control device for a refrigerator, comprising a determining means for determining that the detecting means is abnormal, and a means for displaying an abnormality when the abnormality is determined.