JPH0774716B2 - Operation control device for refrigerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refrigerator operation control device.

2. Description of the Related Art FIG. 4 shows the configuration of a conventional refrigerator operation control device. Reference numeral 1 is an inside temperature detecting means for detecting an inside temperature, 2 is a set temperature detecting means for detecting a set temperature, 3 is an amount of frost accumulated in a cooler, and a defrosting start signal is given when a predetermined amount of frost is reached. Defrosting start detecting means 4 for outputting is a defrosting ending detecting means for detecting when the temperature of the cooler becomes a predetermined temperature or more during defrosting and ending the defrosting. Reference numeral 5 is a control means, which is an input terminal I ₀ , I
_{It has 1} , I ₂ , I ₃ and output terminals O ₀ , O ₁ . Then, the inputs from the in-compartment temperature detecting means 1 and the set temperature detecting means 2 are compared, and the rotation speed of the compressor 6 is determined according to the temperature of both.

For example, in the case of "inside temperature <set temperature", the compressor 6 is stopped, in the case of "inside temperature> set temperature", the compressor 6 is operated at a high rotation speed, and when inside temperature = set temperature It is determined that the compressor 6 is operated at a low rotation speed and the like, and is output from the output terminal O ₀ . 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.

Reference numeral 8 denotes a relay, which has a contact 8'and turns on / off the contact 8'by the output of the control means 5 to turn on / off the defrosting heater 9.

10 is a rapid cooling setting means, which sends a rapid cooling start signal to the control means 5 to cool the inside of the refrigerator from the normal operation.

Considering the time when the power of the refrigerator is turned on for the first time in such a configuration, the inside of the refrigerator is almost the same as the outside air temperature, and the inside temperature> the set temperature, and the control means 5 operates the compressor 6 at a high rotation speed. Decide to do. Therefore, the compressor operates at a high rotation speed. The change of the input current applied to the compressor 6 at this time is shown in FIG. Fifth
Point A in the figure is the peak value of the motor current. The time T from the start of operation to the peak of the current value is usually about
It takes 30 minutes, which varies depending on the outside temperature, the temperature inside the refrigerator, and the cooling system. Similarly, when the internal load becomes very large (for example, when a hot one is put in), there is a peak value of the current as well.

Problems to be Solved by the Invention However, in the above-mentioned configuration, a very large current flows at point A in FIG. 5, and an element such as a transistor capable of withstanding this current is not used for the operation control means 7. It did not happen, and it was expensive.

The present invention reduces the current peak value at point A shown in FIG.
In the case of a rapid cooling operation in which cooling is attempted compared to normal operation, the elements such as transistors used in the operation control means can be made to have a small capacity without significantly deteriorating their performance, and the cost of the operation control means can be reduced to reduce the ambient temperature. The purpose of the present invention is to provide an operation control device for a refrigerator that can respond to changes in the internal temperature and the cooling system.

Means for Solving the Problems In order to solve the above problems, the operation control device for a refrigerator of the present invention includes a current detecting means for detecting an input current supplied to a compressor of the refrigerator, and a current detecting means at the time of normal operation. First timer means for starting the operation when it is determined that the current is larger than a predetermined value, and the operation is started when the current detecting means determines that the current is larger than the predetermined value during the rapid cooling operation by the rapid cooling setting means. The second timer means is provided.

Action The present invention detects the input current applied to the compressor by the above-mentioned configuration, and when the current value reaches a predetermined value, changes the rotation speed of the compressor to a low rotation speed to reduce the current peak value after the power is turned on. The stable operation is performed even with changes in the outside temperature, the inside temperature, and the cooling system. In addition, even in the rapid cooling operation in which the inside of the refrigerator is cooled from the normal operation, the operation can be performed without degrading its performance as much as possible.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings. First
The figure is a diagram showing a configuration of an embodiment of the present invention, the internal temperature detection means 1, set temperature detection means 2, defrost start detection means 3, defrost end detection means 4, control means 5, compressor 6, The relay 8, the heater 9, and the rapid cooling setting means 10 have the same configuration as the conventional example.

Reference numeral 7 denotes an operation control means, which is a DC brushless motor drive circuit that switches the voltage applied to each phase of the winding while detecting the rotation of the motor of the compressor 6 and changes the rotation speed by controlling the voltage applied to the motor. (Hereinafter referred to as operation control means). Reference numeral 11 is a current detecting means for detecting an input current supplied to the compressor 6 by, for example, a CT (current transformer) 11 'and sending an output to the control means 5 when the current exceeds a predetermined value. Reference numeral 12 denotes a first timer means, which starts operation when the current detection means 11 determines that the current is larger than a predetermined value during normal operation. Reference numeral 13 denotes a second timer means, which starts operation when the current detection means 11 determines that the current is larger than a predetermined value during the rapid cooling operation by the rapid cooling setting means 10.

The operation will be described below with reference to FIGS.

In one step, the internal temperature detected by the internal temperature detecting means 1 is input from the input terminal I ₀ . Next, in step 2, the set temperature detected by the set temperature detecting means 2 is input from the input terminal I ₁ . Next, in 3 steps, the inside temperature input in 1 step is compared with the set temperature input in 2 steps, and the rotation speed of the compressor 6 is determined in 4 steps. In 5 steps, it is judged whether or not the first timer means 12 is operating, and if it is operating, it proceeds to 13 steps, and if it is not operating, it proceeds to 6 steps. In 6 steps, it is judged whether or not the second timer means is operating, and if it is operating, it proceeds to 13 steps, and if it is not operating, it proceeds to 7 steps. In step 7, the input current value given to the compressor 6 detected by the current detection means 10 is input. In 8 steps, it is judged whether or not the current value input in 7 steps is larger than a predetermined value, and if it is larger or equal, the step proceeds to 10 steps, and if it is smaller, the step proceeds to 9 steps and the rotational speed determined in 4 steps is set to the operation control means. Output to 7. This 8
When the process proceeds to step 9 as a result of the determination in step, the input current value is in a state in which there is a margin for the elements of the operation control means 7, and the determined rotation speed is output as it is. However, as a result of the judgment in 8 steps, if the process proceeds to 10 steps, it means that the input current value has no margin with respect to the elements of the operation control means 7. In 10 steps, the current operation status is judged, and if it is normal operation, proceed to 12 steps.
Here, the normal operation means that the compressor 6 is operating at the rotation speed determined by the in-compartment temperature detecting means 1 and the set temperature detecting means 2, and the rapid cooling operation means that the inside of the refrigerator is cooled by the rapid cooling setting means 10. Compressor when it becomes necessary to cool it than in normal operation (for example, when the user presses the rapid cooling switch to put food in the refrigerator for quick cooling, or when the temperature in the refrigerator becomes high and it is necessary to perform rapid cooling) It means that 6 is continuously operated at the highest rotation speed. In the 11th step, since it is normal operation, the first timer 12 is activated 13
Go to step. Further, since the rapid cooling operation is performed in 12 steps, the second timer 13 is operated and the operation proceeds to 13 steps. In order to reduce the input current in 13 steps, the intermediate rotational speed lower than the determined rotational speed determined in 4 steps is output to the operation control means 7.

Next, at 14 steps, it is judged from the output of the defrosting start detecting means 3 whether or not defrosting is started. If defrosting is started, the procedure proceeds to 15 steps, and if defrosting is not started, the procedure returns to 1 step.
Normally, the above operation is repeated. If the defrosting start is detected in 14 steps, the process proceeds to 15 steps, and in 15 steps, the compressor 6
The number of revolutions is set to 0 (OFF) and output to the operation control means 7 from the output terminal O ₀ . Next, in step 16, a defrost signal is output from the output terminal O ₁ to turn on the relay 8 to energize the heater 9 to start defrosting.

Next, if there is no output from the output of the defrosting completion detecting means 4 in step 17, the process returns to step 17 and the output of the defrosting completion detecting means 4 is taken in again and defrosting is continued during this period. If there is an output, the process proceeds to step 18, the heater 9 is turned off, the defrosting is completed, and the process returns to step 1.

Thus, as shown in FIG. 3, when the refrigerator is powered on for the first time, the compressor 6 starts operating at a high rotational speed as described above, and the temperature difference between the inlet and the outlet of the cooler disappears. Since the load of the compressor 6 increases and the current value tries to exceed a predetermined value, that is, point B in FIG. 3, at this time, the rotation speed of the compressor 6 is operated at an intermediate rotation speed lower than the current rotation speed, and Control to reduce the value. Further, after the operation completion time T ₁ of the first timer means 12 is exceeded, the operation speed is returned to the operating speed determined by the original internal temperature and the set temperature. Further, even when the internal load becomes large during the rapid cooling operation, when the input current tries to exceed the point B, the rotation speed of the compressor 6 is operated at the intermediate frequency and the current value is controlled to be reduced. Also, the operation completion time of the second timer means
After T ₂ (not shown), return to the speed determined by the original quenching operation. Since T ₁ > T ₂ here, the time for lowering the rotation speed of the compressor 6 (lowering the cooling performance) during the rapid cooling operation is smaller than that during the normal operation, and the effect on the cooling performance is very small.

Therefore, by detecting the input current applied to the compressor 6,
When the current value is higher than a predetermined value, the compressor 6 is operated at an intermediate rotation speed, so that the conventional compressor shown in FIG.
It is possible to reduce peak currents such as dots, to reduce the capacity of the elements such as transistors used for the operation control means 7, and to reduce the cost of the operation control means 7. Further, even if the time to the current peak changes due to changes in the outside air temperature, the temperature inside the refrigerator, and the cooling system, it is possible to prevent excessive current, and stable operation is possible.

Furthermore, not only when the power is turned on, but also the peak current during operation after defrosting can be reduced.

Even during the rapid cooling operation, the peak current can be reduced without significantly lowering the cooling performance.

EFFECTS OF THE INVENTION As described above, according to the present invention, the current detecting means for detecting the input current supplied to the compressor of the refrigerator, and the operation for starting the operation when the current detecting means determines that the current is larger than the predetermined value during the normal operation. By providing one timer means and a second timer means for starting the operation when the current detection means determines that the current is larger than a predetermined value during the rapid cooling operation by the rapid cooling setting means, a transistor or the like used for the operation control means The element can be made to have a small capacity and can be made inexpensive. In addition, stable operation can be realized even with changes in the outside air temperature, the inside temperature, and the cooling system. Further, even during the rapid cooling operation, the above can be realized without significantly lowering the cooling performance.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an operation control device for a refrigerator of the present invention, FIG. 2 is a flow chart, 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 a configuration of a conventional refrigerator operation control device, and FIG. 5 is a diagram showing a change in an input current after a power source is turned on by a conventional control method. 1 ... internal temperature detecting means, 2 ... set temperature detecting means, 5
...... Control means, 7 ...... Operation control means, 10 ...... Rapid cooling setting means, 11 ...... Current detection means, 12 ...... First timer means, 13 ・ ・ ・
... second timer means.

Claims (2)

[Claims] 1. An inside temperature detecting means 1 for detecting the inside temperature.
And a set temperature detecting means 2 for detecting the set temperature of the inside temperature.
A rapid cooling setting means 10 for sending a signal to start the rapid cooling for cooling the inside of the refrigerator from the normal operation, a current detecting means 11 for detecting an input current given to the compressor 6 of the refrigerator, and the inside temperature detecting means 1. Control means 5 for determining and sending the rotation speed of the compressor 6 based on the outputs of the set temperature detection means 2 and the current detection means 11, and an operation for operating the compressor 6 at the rotation speed determined by the control means 5. The control means 7, the first timer means 12 that starts the operation when the current detection means 11 determines that the current is larger than a predetermined value during the normal operation, and the current detection during the rapid cooling operation by the rapid cooling setting means 10. When the means 11 judges that the current is larger than a predetermined value, it comprises a second timer means 13 which starts the operation, and when the input current given to the compressor 6 exceeds a predetermined value, the inside of the refrigerator When the rotation speed of the compressor 6 determined by the temperature and the set temperature is changed to a low rotation speed and the operation of the first timer means 12 or the second timer means 13 is completed, the inside temperature and the set temperature An operation control device for a refrigerator, which controls to return to the rotation speed of the compressor 6 set by. 2. The operation control device for a refrigerator according to claim 1, wherein the operating time of the first timer means 12 is longer than the operating time of the second timer means 13.