JPS6315065A - Freezing refrigerator - 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 (Industrial Field of Application) The present invention relates to a refrigerator-freezer that cools the inside of the refrigerator by forcibly circulating cold air using a cold air circulation fan.

[Conventional technology]

Conventional refrigerator-freezers use a defrost heater to heat the cooler to defrost the refrigerator, so the temperature inside the refrigerator rises before the defrost is finished. It took a long time for the temperature to drop to the set temperature, which had a negative impact on the food stored in the refrigerator.

FIG. 7 is an electrical circuit diagram of a main part of a refrigerator/freezer disclosed in, for example, Japanese Utility Model Application Publication No. 56-149881, which has been proposed as an MA solution to solve these problems.

In the figure, 51 is a power plug, 52 is an electromagnetic switch, 5
3 is a compressor electric motor that drives the compressor, 54 is an electronic control unit, 55 is an internal temperature detection element, 56 is an electromagnetic switch, 57
is the door switch, 58 is the electric motor for the cold air circulation fan, 59
is a resistor, 60 is an electromagnetic switch, and a compressor motor 53
The two-pole terminal 52p and the four-pole terminal 54p are respectively connected to fixed contacts 52a and 52b in the electromagnetic switch 52,
The switching piece 52c of this electromagnetic switch 52 is connected to the power plug 51.
The other end of the compressor motor 53 is connected to the other end of the power plug 51 via a switching contact piece 56a of the electromagnetic switch 6. The electronic control unit 54 includes an internal temperature detection element 55 and an electromagnetic coil 52d of the electromagnetic switch 52.
and the electromagnetic coil 56b of the electromagnetic switch 56 are connected to each other. Further, the resistors 59a and 59b are connected to the fixed contacts 60a and 60b of the electromagnetic switch 60 described above, respectively, the switching contact piece 60c is connected to one end of the power plug 51, and the other end of the resistors 59a and 59b is connected to the cold air circulation fan. The compressor 7a motor 58 is connected to the other end of the power plug 51 via the door switch 57 in parallel with the compressor 7a motor 53. Further, 60d is an electromagnetic switch 60 connected to the electronic control unit 54.
shows the electromagnetic coil.

Next, the effect will be explained.

The electronic control unit 54 sets the operating time of the compressor motor 53, and when the operating time reaches a predetermined time, the defrosting operation is forcibly started. When the compressor motor 53 operates for the first time after defrosting, the electronic control section 54 is operated by a signal from the internal temperature detection element 55, and the electromagnetic coil 56b of the electromagnetic switch 56 is excited and switched. At the same time as the contact piece 56a is switched, the electromagnetic coil 52d of the electromagnetic switch 52 is excited, and the switching contact piece 52c is switched. Then, the compressor electric motor 53 is operated at high speed with two poles, and the electromagnetic coil 60d of the electromagnetic switch 60 is similarly excited by the operation of the electronic control unit 54, the switching contact piece 60c is switched, and the cold air circulation fan electric motor 58 is activated. is operated at high speed, and rapid cooling is forcibly performed at the beginning of the end of weight removal rtk. Therefore, the time required for the air temperature in the refrigerator to drop as shown by the solid line in FIG. 8 and for the compressor electric motor R53 and the cold air circulation fan electric motor 58 to return to normal operation is shortened by the time t2.

[Problem that the invention seeks to solve]

Conventional refrigerator-freezers have a configuration in which an electronic control unit 54 accumulates the operating time of the compressor motor 53, and every time this accumulated time exceeds a predetermined time, the operation of the compressor is stopped and the cooler is defrosted. Therefore, defrosting is performed with the cooler filled with liquid refrigerant, and the electric heat of the defrost heater is used not only to melt the frost, but also to heat the cooler and the liquid refrigerant inside the cooler. It is consumed to heat the air in the cooling chamber, and as a result, the temperature inside the refrigerator rises by the time defrosting is finished, and this increased temperature inside the refrigerator has a significant negative effect on the food stored in the refrigerator. There was a problem that the storage period was shortened.

This invention was made to solve the above-mentioned problems, and its purpose is to shorten the defrosting time.

[Means for solving problems]

The refrigerator-freezer according to the present invention includes a refrigerant circuit having a compressor, a radiator, and a cooler, a cold air circulation fan that forcibly circulates cold air in a cooling chamber installed in the cooler within one city, and a defrosting device for the cooler. A refrigerator-freezer having a defrosting heater that performs the following operations, wherein the compressor control means causes the compressor to start operating at a low speed at a predetermined time point, and the defrosting heater is turned on by the heater control means to start operating the compressor at a low speed. is being stopped.

[Function] The compressor control means of the present invention starts low-speed operation of the compressor when a scheduled time has elapsed, and stops the operation when defrosting starts when the defrosting heater is turned on. The amount of liquid refrigerant present in the cooler decreases, and the temperature of the cooler increases just before the start of defrosting, and the amount of liquid refrigerant present in the cooler decreases. Therefore,
The amount of heat required to complete defrosting is reduced accordingly.
Defrosting time is shortened.

(Example of the invention) Fig. 1 shows a first embodiment of the invention.
1 is the refrigerator body, 2 is a cold air circulation fan installed at the top of the cooling chamber 3, 4 is a cooler installed in the cooling chamber 3, 5 is a defrost heater installed at the bottom of the cooler 4, 6 is a compressor, 7 is a compressor rotation speed control section that controls the rotation speed of the compressor 6. 8 is an electronic control unit as a means for controlling the heater j, which measures the elapsed time immediately after the end of defrosting, and calculates the estimated elapsed time 6.9
The electronic control section 8 is connected to the compressor rotation speed control section 7 by energizing the defrosting heater 5 at a point to start defrosting.
Together, they constitute a compressor control means, which controls the compressor rotational speed control section 7 by +&IJ to start the compressor 6 at a low speed after a predetermined period of time has elapsed, and to stop the operation when defrosting starts. Further, the electronic control unit 8 controls the cold air circulation fan 2*oN10FF. In the refrigerator-freezer of this embodiment, when the scheduled time elapses, the electronic control unit 8 controls the compressor rotation speed j=+control unit 7 by 1t (I) to start the compression R6 at low speed, so that defrosting is started. On the surface 11η, the liquid refrigerant t11 flowing into the cooler 4 decreases, and the temperature of the cooler 4 increases by the amount of the liquid refrigerant decreased.

In addition, at the start of defrosting, the electronic control unit 8 turns on the defrost heater 5 to heat the cooler 4, whose temperature has increased by decreasing h[ of the liquid refrigerant, and also turns on the compressor 6 and the cold air circulation fan 2. Since I configured it to stop operation,
The amount of heat required to heat the cooler 4 and the liquid refrigerant remaining in the cooler 4 until the defrosting is finished is reduced, and the time required for defrosting is shortened. Therefore, the rise in temperature inside the refrigerator is small, and the temperature returns to the set temperature in a short time after defrosting.

Figure 7P13 shows the 'A2 embodiment of this invention. 1st
The same or corresponding parts as in the figures are given the same reference numerals. In the figure, 20 is a cooler temperature detection sensor attached to the cooler 4. 2! In addition to performing essentially the same control as the electronic control unit 8 of the embodiment, it also acts as a cooler temperature comparing means to compare the temperature of the cooler 4 with a scheduled temperature, and controls the defrost heater 5 and the cooler 4 It turns ON when the temperature exceeds the scheduled temperature, and turns OFF when defrosting is completed.

The refrigerator-freezer of this embodiment compares the cooler temperature detected by the cooler temperature detection sensor 20 with the scheduled temperature when the compressor fi6 is operated at low speed by the compressor control means after the scheduled time has elapsed. This is an example in which the defrost heater 5 is activated to start defrosting when the detected cooler temperature exceeds the scheduled temperature, and defrosting can be performed according to the internal load and the amount of frost on the cooler 4. There is an effect that it can be done.

FIG. 4 shows an example of the relationship between the control timing of the compressor 6, cold air circulation fan 2, and defrost heater 5 and the cooler temperature in this embodiment.

FIG. 5 shows a third embodiment of the invention. The same or corresponding parts as in FIG. 1 are given the same reference numerals. In the figure, 30 is a cold air temperature detection sensor that is disposed at the cold air outlet of the cold air circulation fan 2 and detects the temperature of the cold air blown out by the cold air circulation fan 2, and 31 is a cold air temperature detection sensor that detects the air temperature inside the refrigerator. This is an internal temperature detection sensor. Reference numeral 32 denotes an electronic control unit which performs essentially the same control as the electric f-control unit 8 of the first embodiment, and also serves as cold air temperature comparison means to compare the cold air temperature detected by the cold air temperature detection sensor 30 with the cold air temperature detected by the cold air temperature detection sensor 30. Compare the internal temperature detected by the internal temperature detection sensor 31,
The defrosting heater 5 is turned ON when the cold air temperature exceeds the internal air temperature, and is turned 0F when defrosting is completed.

In the refrigerator-freezer of this embodiment, when the compressor 6 is operated at low speed by the compressor control means after a scheduled time, the cold air temperature detected by the cold air temperature detection sensor 30 and the temperature detected by the refrigerator temperature detection sensor 31 are detected. In this example, the electronic control unit 32 compares the internal air temperature with the internal air temperature, and when the cold air temperature becomes higher than the internal air temperature, the defrost heater 5 is turned on to start defrosting. This has the advantage of not causing an excessive increase in

FIG. 6 shows an example of the relationship between the ;b control timing of the If compressor 6 and the defrost heater 5 and the cool air temperature and the internal air temperature in this embodiment.

(Effects of the Invention) This invention is configured to start the pressure 1? The cooler, whose temperature has increased due to a decrease in the amount of liquid refrigerant flowing into the cooler, is heated by the defrost heater at the start of defrosting, and the compressor is stopped, so that the temperature rises by the time defrosting is completed. This has the effect that the amount of heat required to heat the cooler and the liquid refrigerant remaining in the cooler is reduced, and the time required for defrosting is shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the main parts of a first embodiment of the present invention, FIG. 2 is a diagram showing the relationship between the operation timing of the compressor and defrost heater and the internal air temperature, and FIG. A block diagram showing the second embodiment, FIG. 4 is a diagram showing the relationship between the operating timing of the compressor and the defrosting heater and the cooler temperature, FIG. 5 is a diagram showing the third embodiment of the present invention, and FIG. Figure 8 is a diagram of the relationship between the operating timing of the compressor and defrost heater and the internal air temperature and cold air temperature, 'fS7 and 1 is the main electrical circuit diagram of a conventional refrigerator-freezer, and Figure 8 is for the compressor and cold air circulation fan. FIG. 3 is a diagram showing the relationship between the operation timing of the electric motor and the internal air temperature. In the figure, 2...Cold air circulation fan, 3...1 cooling power chamber, 4...Cooler, 5...Defrost heater, 6...
- Compressor, 8... Electronic control unit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] (1) A refrigerant circuit that includes a compressor, a radiator, and a cooler, a cold air circulation fan that forcibly circulates cold air from a cooling room in which the cooler is installed into the refrigerator, and a defrost heater that defrosts the cooler. The refrigerator-freezer is characterized by comprising a heater control means for controlling ON/OFF of the defrosting heater, and a compressor control means for starting the compressor at a low speed when a scheduled time elapses and stopping the compressor when defrosting starts. Freezer/refrigerator. (2) The heater control means is a means for turning on the defrosting heater when a predetermined time has elapsed from the elapsed scheduled time and turning it off when defrosting is finished. refrigerator-freezer. (3) The heater control means is a cooler temperature comparison means that turns on the defrosting heater when the temperature of the cooler exceeds a predetermined temperature and turns it off when defrosting is completed. The refrigerator-freezer according to item 1 or 2. (4) The heater control means is a cold air temperature comparison means that turns on the defrosting heater when the temperature of the cold air blown out by the cold air circulation fan exceeds the temperature inside the refrigerator, and turns it off when defrosting is completed. A refrigerator-freezer according to any one of claims 1 to 3, characterized in that: