JPH0618884U - Refrigerator defroster - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide a defrosting device for a cold air circulation type refrigerator, which is capable of shortening the defrosting time and safely maintaining the quality of stored food. [Structure] An operation integration timer that integrates the operation time of the compressor and defrosts the evaporator at regular intervals, a defrost temperature sensor that detects completion of defrosting, and a circulation fan reverse rotation circuit that reversely rotates the circulation fan. And a control microcomputer that controls the same circulation fan reverse rotation circuit, and the control microcomputer intermittently reverses the rotation of the circulation fan after a definite period of time has elapsed from the start of defrosting.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a defroster for a refrigerator, and more particularly to a defroster for a cold air circulation refrigerator.

[0002]

[Prior art]

 Conventionally, in a cold air circulation refrigerator, the cold air generated by the evaporator installed in the freezer compartment is sent to the freezer compartment and each refrigerating compartment by a circulation fan, and the inflow volume is adjusted by the dampers installed in each compartment, Is controlled to reach a predetermined temperature state. If operated for a long time in this state, frost may form on the evaporator or the inner wall of the refrigerator, covering the surface of the evaporator and heat transfer, though the degree depends on the amount of food stored and the frequency of food intake and removal. In order to obstruct and cool air circulation in the refrigerator, the frosted state is detected by the defrosting temperature sensor attached to the evaporator, or the operation integration timer shows a constant operation time as shown in Fig. 2 (b). In this way, the operation of the compressor and circulation fan is forcibly stopped, and a dedicated defrost heater is energized to defrost. In this case, if the amount of frost is large, it will take time to complete defrosting, the temperature of the evaporator and the temperature inside the refrigerator will rise, and the temperature inside the refrigerator will not immediately drop even after returning to the cooling operation. Are causing problems that impair the quality of.

[0003]

[Problems to be solved by the device]

 The present invention has been made in view of the above-mentioned conventional problems, and by shortening the time required for defrosting, the rise in the temperature of the evaporator and the inside of the refrigerator can be suppressed low, and the quality of the stored food can be impaired. It is intended to provide a defroster for refrigerators that does not exist.

[0004]

[Means for Solving the Problems]

 In order to achieve the above purpose, the circulation fan is intermittently reversely rotated in the latter half of the defrosting process to blow air on the evaporator.

[0005]

[Action]

 According to the above configuration, the circulation fan is intermittently reversely rotated in the latter half of the defrosting period to prevent the heat of the defrosting heater that is energized during defrosting from being diffused and send it back to the evaporator. As soon as possible, the temperature inside the freezer is kept from rising.

[0006]

【Example】

 Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of the present invention. An operation integration timer 2 that drives only when the compressor 1 is in operation and integrates the operation time, and a defrosting temperature that is attached to the evaporator and detects the temperature of the evaporator The sensor 3, the control microcomputer 4 that controls the defrosting operation by the signals from the operation integration timer 2 and the defrosting temperature sensor 3, the compressor drive circuit 5 and the compressor 1 that are controlled by the control microcomputer 4, It is composed of a frost heater drive circuit 6, a defrost heater 7, a circulation fan forward rotation circuit 8, a circulation fan reverse rotation circuit 9 and a circulation fan 10.

The operation integration timer 2 is driven at the same time as the compressor 1 starts the cooling operation, and is turned on / off in accordance with the temperature control of the compressor 1 to integrate the operation time of the compressor 1 and the integration time. When the predetermined defrosting start time is reached, the cam mechanism sends a defrosting start signal to the control microcomputer 4 to stop the operation of the compressor 1 and energize the defrosting heater 7. The control microcomputer 4 stops the compressor 1 via the compressor drive circuit 5 by the defrost start signal, stops the circulation fan 10 by the circulation fan forward rotation circuit 8, and energizes the defrost heater 7 by the defrost heater drive circuit 6. Then start defrosting the evaporator. After a certain period of time has passed since the start of defrosting, the control microcomputer 4 intermittently turns on and off the circulation fan 10 by the circulation fan reverse rotation circuit 9 to blow air to the evaporator to accelerate defrosting of the evaporator.

FIG. 2A is a defrosting time chart of the present invention, in which the compressor 1 and the circulation fan circulation fan 10 are stopped at the same time when defrosting is started, the defrosting heater 7 is energized, and a certain period of time is elapsed after defrosting is started. When the time passes, the control microcomputer 4 intermittently rotates the circulation fan 10 in the reverse direction, and when the temperature of the evaporator reaches a predetermined defrosting end temperature, the defrost heater 7 is de-energized to rotate the circulation fan 10 in the reverse direction. Stop and start the operation integration timer 2 at the same time, start the operation of the compressor 1 and the circulation fan 10 in the normal rotation operation after the lapse of a predetermined rest time by the cam mechanism of the operation integration timer 2, and return to the cooling operation. I am trying.

FIG. 3 is a flowchart showing the details of the present invention. When the operation integration timer 2 reaches the defrosting start time (21), the operation integration timer 2 is stopped, and at the same time, the operation of the compressor 1 and the circulation fan 10 are stopped. Then, the defrosting heater 7 is energized to start defrosting (22). After a lapse of a certain time t from the start (23), the control microcomputer 4 intermittently reverses the circulation fan 10 in the reverse direction (24), and the defrost temperature sensor 3 raises the temperature of the evaporator to a predetermined temperature, thereby defrosting. When it is judged that the temperature has reached the completion temperature (25), the defrost heater 7 is turned off, the circulation fan 10 is stopped, and at the same time the operation integration timer 2 is started (26), and the operation integration timer is elapsed after a predetermined time has elapsed. When 2 reaches the operation start time of the compressor 1 (27), the operation of the compressor 1 is started, and at the same time, the circulation fan 10 is normally rotated to return to the normal cooling operation (28).

[0010]

[Effect of device]

 As described above, in the present invention, the circulation fan is intermittently reversely rotated in the latter half of the defrosting process to prevent the heat of the defrosting heater from being diffused and to remove the frost adhering to the evaporator. Defrosting can be accelerated and the temperature rise in the freezer compartment can be suppressed, so that the quality of stored food can be maintained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a defrosting time chart.

FIG. 3 is a flowchart showing details of the present invention.

[Explanation of symbols]

 1 Compressor 2 Operation integration timer 3 Defrost temperature sensor 4 Control microcomputer 5 Compressor drive circuit 6 Defrost heater drive circuit 7 Defrost heater 8 Circulation fan forward rotation circuit 9 Circulation fan reverse rotation circuit 10 Circulation fan

Claims (1)

[Scope of utility model registration request] 1. Cold air generated by an evaporator provided in a freezer compartment is sent to a freezer compartment and each refrigerating compartment by a circulation fan to cool the inside of the compartment, and a frost accumulated on the evaporator at regular intervals by an operation integration timer. In a cold air circulation type refrigerator configured to defrost by means of a defrost heater, a refrigerator characterized in that the circulation fan is intermittently reversely rotated in the latter half of the defrosting period to blow air on the evaporator. Defroster.