JPS6191474A - Controller for operation of 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 applications The present invention relates to an operation control device for a refrigerator.

Conventional configuration and its problems The configuration of a conventional refrigerator operation control device is shown in FIG. Reference numeral 1 indicates an internal temperature detection means for detecting the internal temperature of the refrigerator, 2 indicates a set temperature detection means for detecting the set temperature, and 3 detects the amount of frost accumulated in the cooler, and issues a defrosting start signal when a predetermined amount of frost is reached. 4 is a defrosting end detecting means that detects when the temperature of the cooler reaches a predetermined temperature or higher during defrosting and ends the defrosting. 5 is a control means, which is an input terminal.

. III Output terminal o0. o1.

11 2 3S Then, the inputs from the chamber temperature detection means 1 and the set temperature detection means 2 are compared, and the compressor 6 is activated depending on the magnitude of both temperatures.
Determine the number of rotations.

For example, if the internal temperature is <set temperature>, the compressor 6 is stopped, if the internal temperature is <set temperature>, the compressor 6 is operated at high rotation speed, and if the internal temperature is equal to the set temperature, the compressor 6 is stopped. It decides to operate the compressor 6 at a low rotation speed, and outputs the output from the output terminal O0. Reference numeral 7 denotes an operation control means, which is, for example, a transistor inverter, which receives the rotation speed determined by the control means 5 and operates the compressor 6 at the rotation speed.

8 is a relay, which has a contact 8', and the output of the control means 6 causes the contact 8'0N10FFL to switch the defrosting heater 9 to ○N/○.
This is to cause FF.

In such a configuration, when the power is turned on for the first time, the temperature inside the refrigerator is almost the same as the outside temperature, and the temperature inside the refrigerator is higher than the set temperature, and the control means 6 operates the compressor 6 at a high rotation speed. decide to. Therefore, the compressor is operated at high rotational speed. FIG. 5 shows changes in the input current applied to the compressor 6 at this time. Fifth
Point A in the figure is the peak value of the motor current. Further, the time T from the start of operation until the current value reaches its peak is usually about 30 minutes, and varies depending on the outside temperature, the inside temperature, and the cooling system.

Therefore, a very large current flows at point A, and elements such as transistors that can withstand this current must be used in the operation control means 7, which is expensive.

Purpose of the Invention Therefore, the present invention aims to reduce the current peak value at point A shown in FIG. 2, and to reduce the cost of the operation control means by making elements such as transistors used in the operation control means small in capacity. It is an object of the present invention to provide a control device that can cope with changes in outside temperature, inside temperature, and cooling system.

Structure of the Invention To achieve this object, the present invention detects the input current applied to the compressor, changes the rotation speed of the compressor when the current value reaches a predetermined value, and reduces the peak current value after power is turned on. ,Outside temperature.

This ensures stable operation even in response to changes in the internal power supply and cooling system.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1st
The figure is a diagram showing the configuration of an embodiment of the present invention, in which chamber temperature detection means 1. Set temperature detection means 2゜Mist removal start detection means 3
．． Defrosting completion detection means 4. Control means 5. compressor 6,
Relay 8. The heater 9 has the same configuration as the conventional example.

Reference numeral 7 denotes an operation control means, which is a DCC brushless morph circuit that detects the rotation of the motor of the compressor 6, switches the voltage applied to each phase of the winding, and changes the rotation speed by controlling the voltage applied to the motor. (hereinafter referred to as operation control means).

10 is an input current given to the compressor 6, for example CT (
This current detecting means detects the current by the current transformer (current transformer) 10' and sends an output to the control means 5.

The operation will be explained below with reference to FIG.

In one step, the temperature inside the refrigerator detected by the temperature inside the refrigerator 1 is input to the terminal. Enter more information.

Next, in two steps, the set temperature detected by the set temperature detection means 2 is inputted through the input terminal. Next, in 3 steps, the internal temperature input in 1 step is compared with the set temperature input in 2 steps, and in 4 steps, the rotation speed of the compressor 6 is determined.

In 5 steps, the input current value to be applied to the compressor 6 detected by the current detection means 1o is input. In step 6, it is determined whether the current value inputted in step 5 is greater than a predetermined value, and if it is greater or equal, the process proceeds to step 7; if it is smaller, the process proceeds to step 8, and the rotation speed determined in step 4 is controlled by the operation control means. Output to 7. If the process proceeds to step 8 as a result of the judgment made in these 6 steps, the input current value is in a state where there is sufficient margin for the elements of the operation control means 7, and the determined rotational speed is output as is. Next 9
Proceeding to step 3, it is determined whether or not defrosting has started based on the output of the defrosting start detection means 3. If defrosting has started, the process advances to step 10, and if defrosting has not started, the process returns to step 1. Normally, repeat the above operation. When the compressor 6 is operated as described above and the cooling operation is performed when the power is turned on or when the operation is completed after defrosting, the cooling load of the refrigerator gradually increases and the input current value given to the compressor 6 exceeds the predetermined value. Sometimes, the process proceeds from the 6th step to the 7th step, where the control means 5 outputs an intermediate rotational speed to the operation control means 7 for the rotational speed determined in the 4th step, and the process proceeds to the 9th step. If the start of defrosting is detected in the 9th step, the process proceeds to the 10th step, and in the 1o step, the rotation speed of the compressor 6 is set to ○ rotations (OFF) and the output terminal ○ is set. It is output to the operation control means 7. Next, in step 11, a defrosting signal is output from the output terminal 01, the relay 8 is turned on, and the heater 9 is energized to start defrosting.

Next, in step 12, if there is no output from the defrosting end detecting means 4, the process returns to step 12, and the output of the defrosting end detecting means 4 is taken in again, and defrosting is continued during this time.

If there is still output, proceed to step 13, complete the defrosting of the heater 9 to 0FFL, and return to step 1.

As shown in Figure 3, when the refrigerator is first powered on, the compressor 6 starts operating at a high rotational speed as described above, and the temperature difference between the inlet and outlet of the cooler disappears. The load on the compressor 6 increases and the current value tends to exceed a predetermined value, that is, point B in FIG. 3. At this time, the compressor 6 is operated at an intermediate rotation speed and controlled to reduce the current value . Furthermore, when the current value is adjusted to a predetermined value, the operating rotation speed is returned to the original temperature determined by the internal temperature and the set temperature, so that there is no significant effect on the cooling performance.

Therefore, by detecting the input current given to the compressor 6,
By operating the compressor 6 at an intermediate rotation speed when the current value is higher than a predetermined value, the third
Operation control means 7 can reduce the peak current as shown at point A in the figure.
Elements such as transistors used in the present invention can be made to have small capacitance, and the configuration of the operation control means 7 can be made inexpensive. Also the outside temperature.

Even if the time until the current peak changes due to changes in the internal temperature and cooling system, excessive current can be prevented and stable operation is possible.

Furthermore, it is possible to reduce the peak current not only when the power is turned on but also during operation after defrosting.

In Figures 3a and 3C, A indicates the characteristics of the present invention, ``A'' indicates the characteristics of the conventional example, and ``C'' indicates the temperature inside the refrigerator, ``2'' indicates the temperature at the outlet of the cooler, and ``E'' indicates the inlet of the cooler. It indicates temperature.

Effects of the Invention As is clear from the above explanation, the refrigerator operation control device of the present invention determines the rotation speed of the compressor based on the internal temperature of the refrigerator and the set temperature, detects the input current given to the compressor, and detects the input current applied to the compressor. Since the rotational speed is controlled by changing the rotational speed, elements such as transistors used in the operation control means can be made to have a small capacity and can be made inexpensive. It's still outside temperature.

Stable operation can be achieved even with changes in the internal temperature and cooling system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the refrigerator operation control device of the present invention, FIG. 2 is a flowchart, and FIG. 3 is a diagram showing changes in input current when the operation control device of the present invention is used. FIG. 4 is a diagram showing the configuration of a conventional refrigerator operation control device, and FIG. 5 is a diagram showing changes in input current after power is turned on according to the conventional control method. 1... Inner temperature detection means, 2... Preset temperature detection means, 6... Control means, 7...
・Operation control means, 1°...Current detection means. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3

Claims (2)

[Claims] (1) An internal temperature detecting means for detecting the internal temperature, a set temperature detecting means for detecting the set temperature of the internal refrigerator, a current detecting means for detecting the input current given to the compressor of the refrigerator, and the internal temperature A control means that determines and sends out the rotation speed of the compressor based on inputs from the detection means, the set temperature detection means, and the current detection means, and an operation control means that operates the compressor at the rotation speed determined by the control means. An operation control device for a refrigerator, which changes and controls the rotation speed of the compressor determined by the internal temperature and the set temperature when the input current applied to the compressor exceeds a predetermined value. (2) A refrigerator operation control device according to claim 1, which reduces and controls the rotation speed of the compressor determined by the internal temperature and the set temperature when the input current applied to the compressor exceeds a predetermined value. .