JPH033152B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a defrosting control device for a refrigerator.

Conventional configuration and its problems Conventional refrigerator defrosting control integrates the operating time of the compressor, and when the integrated time reaches the set time, the compressor is stopped, the heater is energized, and defrosting is started. was common. However, in a refrigerator in which the frequency (rotation) of the compressor is changed according to the internal load, the cooling capacity of the refrigerator changes in accordance with the change in the frequency (rotation) of the compressor. For this reason, the amount of frost on the cooler changes depending on the rotation speed of the compressor, so if you start defrosting after a certain amount of compressor operation time, the amount of frost on the cooler will increase if high-frequency operation continues for a long time. Therefore, a problem arises in which defrosting is not started even if the cooling capacity is insufficient. In addition, if low frequency operation continues for a long time, there will be a problem in which defrosting will start despite the amount of frost that does not require defrosting, resulting in a decrease in cooling capacity and unnecessary defrosting. Timer defrosting has not yet been found to solve this problem.

Purpose of the invention Therefore, the present invention eliminates the reduction in cooling capacity and unnecessary defrosting in devices that use timer defrosting,
The purpose is to start defrosting at an appropriate time.

Structure of the Invention In order to achieve the above-mentioned object, the present invention provides an internal temperature detecting means for detecting the internal temperature, a preset temperature detecting means for setting the internal temperature, the internal temperature detecting means, and the preset temperature detecting means. temperature difference comparison means for comparing the inputs from the temperature difference comparison means; a frequency determination means for determining and transmitting the operating frequency of the compressor based on the comparison result of the temperature difference comparison means; A frequency control means for operating the compressor, a pulse generation means for changing the number of generated pulses per unit time based on the output of the frequency determination means, and a defrosting start signal when the number of pulses from the pulse generation means is counted and a certain number is counted. a defrosting control means that receives a defrosting start signal from the timer and energizes the defrosting heater; and a defrosting means that detects the temperature of the cooler and notifies the defrosting control means that defrosting has ended. The configuration consists of a switch.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 indicates an internal temperature detection means for detecting the internal temperature, and reference numeral 2 indicates a set temperature detection means for detecting a set temperature. 3 is a defrost switch that detects when the temperature of the cooler reaches a predetermined value or higher during defrosting and ends defrosting. 4 is a control means;
It has input terminals I ₁ , I ₂ , I ₃ and output terminals O ₁ and O ₂ . Then, the inputs from the chamber temperature detection means 1 and the set temperature detection means 2 are compared, and the frequency of the compressor 5 is determined according to the magnitude of the temperature difference between the two. The frequency of this compressor 5 is determined, for example, within the temperature range shown in FIG. First, when the compressor 5 is stopped and the temperature inside the refrigerator rises, the control means 4 determines to operate the compressor 5 at a low frequency when the value of one set temperature in the refrigerator reaches +1°C. Then, if the temperature inside the refrigerator still rises and the value of the temperature inside the refrigerator minus the set temperature reaches 3° C., it is decided to operate at high frequency. In addition, if the temperature inside the refrigerator after cooling down decreases, it is decided to start low-frequency operation when the value of the inside temperature - set temperature is +1℃, and to stop the compressor 5 when the value of the set temperature is -1℃, and the output terminal O This is what is output from ₁ .

Next, the configuration that performs the function of the control means 4 will be explained. The control means 4 includes a temperature difference comparison means 10 which compares the internal temperature and the set temperature and outputs the comparison result, and a compressor 5 based on the comparison result of the temperature difference comparison circuit 10.
a frequency determining means 11 which determines the frequency of the signal and sends it from the output terminal _O1 to the frequency control means 6; a pulse generating means 12 which changes the number of pulses per unit time according to the output of the temperature difference comparing means 10; It consists of a timer 7 that counts the number of pulses and sends out an output when a certain number of pulses is counted, and a defrosting control means 13 that outputs from the output terminal O ₂ based on the output of the timer 7 and operates the relay 8 to defrost. .

The temperature difference comparison means 10 calculates the value of the internal temperature minus the set temperature, determines whether the internal temperature is rising or falling, and outputs a comparison result. This means that when the temperature inside the refrigerator rises as shown in Figure 4, the output of the temperature inside the refrigerator < +1℃ ≦ the temperature inside the refrigerator - the temperature setting < +3℃ until the temperature inside the refrigerator - the set temperature < +1℃. Between, the output of the chamber temperature = set temperature is output, and the output of the chamber temperature - set temperature ≧
At +3°C, the internal temperature > set temperature is output. Also, when the temperature inside the refrigerator falls, the temperature inside the refrigerator - the set temperature <
At -1℃, the output when the internal temperature is less than the set temperature is -1℃.
≦Internal temperature - Set temperature < +1℃, internal temperature =
The output of the set temperature is calculated as follows: Internal temperature - Set temperature ≧ +1℃
At this time, the internal temperature>set temperature is output. The frequency determining means 11 stops the compressor 5 when the internal temperature is <the set temperature, and sets the internal temperature>.
When the set temperature is reached, the compressor 5 is operated at high frequency, and when the temperature inside the refrigerator is equal to the set temperature, the compressor 5 is operated at high frequency.
The pulse generating means 12 sends a command to the frequency control means 6 to operate at a low frequency, and the pulse generating means 12 generates a pulse of 0 per unit time when the temperature inside the refrigerator is higher than the set temperature, 2 per unit time when the temperature inside the refrigerator is lower than the set temperature, When the temperature inside the refrigerator is equal to the set temperature, one pulse is generated per unit time.

Further, the temperature difference comparison means 10 is a defrosting control means 13.
When the defrosting control means 13 operates the relay 8 to defrost, it outputs a signal indicating that the internal temperature is less than the set temperature even if there is a difference between the internal temperature and the set temperature. As a result, the frequency determining means 1
1 sends a signal to stop the compressor 5 to the frequency control means 6. Further, at this time, the pulse generating means 12 also stops generating pulses.

The timer 7 is connected to the output of the defrosting control means 13 and clears the counted pulses when defrosting is completed.

The defrosting control means 13 is connected to the input terminal 13 and is used to terminate defrosting by the defrosting switch 3.

The operation will be explained below with reference to FIGS. 2 and 3. FIG. 2 shows the overall control flow of the refrigerator in this embodiment, and FIG. 3 explains a method for changing the count number depending on the frequency of the timer 7.

In FIG. 2, one step is to input the temperature inside the refrigerator detected by the temperature inside the refrigerator 1 to the input terminal.
Enter from ₁ . Next, in two steps, the set temperature detected by the set temperature detection means 2 is input to the input terminal ₂ .
Enter more information. Next, in step 3, the temperature difference comparison means 10 compares the internal temperature input in step 1 and the set temperature input in step 2, and in step 4, the frequency determination means 11 compares them. The operating frequency of the compressor 5 is determined and outputted to the frequency control means 6 from the output terminal _O1 . At this time, the frequency control means 6 operates the compressor 5 at the determined frequency. For example, if the temperature inside the refrigerator is higher than the set temperature, the operating frequency of compressor 5 should be set to 90.
Hz, compressor 5 when chamber temperature = set temperature
The operating frequency of the compressor 5 is 30Hz, and when the temperature inside the refrigerator is less than the set temperature, the operating frequency of the compressor 5 is 0Hz.
In the case of Hz, compressor 5 is set to OFF. Next 5
It is determined in step whether compressor 5 is ON or OFF, and if it is ON, the process proceeds to step 6 and the operating time is accumulated. Also, if it is OFF, it will return to the start,
Repeat steps 1-4. This six-step operation time accumulation method will be explained with reference to FIG. Step a judges whether the operating frequency of the compressor 5 is 90 Hz or not. If it is 90 Hz, the process goes to step b and counts up two count-up pulses per unit time to the timer 7. If it is not 90 Hz, it becomes 30 Hz, and the step Proceeding to step c, the timer 7 counts up one count-up pulse per unit time. Next, proceed to step 7, where the timer 6
It is determined whether the count pulse number of has reached a predetermined number of pulses. Then, if the count pulse number of the timer 7 reaches a predetermined number of pulses, 8
Proceeding to step, the operating frequency of the compressor 5 is set to 0 Hz (OFF) and outputted to the operation control means from the output terminal _O1 . Furthermore, if the predetermined number of pulses has not been reached, the process returns to the start. Next, in 9 steps, a defrost signal is output from output terminal O ₂ and relay 8 is turned on.
Then, the heater 9 is energized to start defrosting. Next, in step 10, input the output of the defrost switch 3,
At step 11, it is determined whether there is an output from the defrost switch 3, and if there is no output, the process returns to step 10 and the output from the defrost switch 3 is input again. If there is an output, proceed to step 12 and turn on the heater 9.
Turn OFF to finish defrosting, clear the timer 7 in step 13, and return to the start.

Therefore, by setting the number of count pulses to the timer 7 to be larger during high-frequency operation and smaller during low-frequency operation, the number of count pulses can be varied depending on the operating frequency of the compressor 5, and the number of count pulses can be varied depending on the operating frequency of the compressor 5. quick,
Defrosting can be performed slowly during low frequency operation, and when low and high frequency operations occur alternately, defrosting can be performed at an intermediate integrated time, so defrosting can be started at an appropriate time.

Effects of the Invention As is clear from the above explanation, the present invention has the following effects:
It is equipped with a defrosting control means that controls the number of count pulses to the timer to be increased during high-frequency operation and decreased during low-frequency operation in accordance with the operating frequency of the compressor, thereby preventing unnecessary defrosting.
It is possible to eliminate the problem that defrosting is too slow and the cooling capacity is reduced.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the defrosting control device for a refrigerator according to the present invention, Fig. 2 is a flowchart, Fig. 3 is a flowchart showing the exchange part of Fig. FIG. 2 is an explanatory diagram of the control method shown in FIG. 1; 1... Inner temperature detection means, 2... Set temperature detection means, 4... Control means, 6... Operation control means, 7
...Timer.

Claims (1)

[Claims] 1. An internal temperature detecting means for detecting the internal temperature, a set temperature detecting means for setting the internal temperature, and a temperature difference comparison means for comparing inputs from the internal temperature detecting means and the set temperature detecting means, Frequency determining means for determining and transmitting an operating frequency of the compressor based on the comparison result of the temperature difference comparing means, frequency controlling means for operating the compressor at the operating frequency determined by the frequency determining means, and the frequency determining means. a timer that counts the number of pulses from this pulse generator and outputs a defrosting start signal when a certain number is counted; and a defrosting start signal generated by this timer. A defrosting control device for a refrigerator includes a defrosting control means that receives the temperature of the cooler and energizes a defrosting heater, and a defrost switch that detects the temperature of the cooler and notifies the defrosting control means that defrosting has ended.