JPH06100409B2 - Operation control device for refrigerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to an operation control device for a refrigerating storage room such as a refrigerator or a showcase.

2. Description of the Related Art In recent years, an operation control device for a refrigerator has been able to perform an optimum operation according to a refrigeration load by controlling a rotation speed of a compressor.

An example of the above-described conventional operation control device for a refrigerator will be described below with reference to the drawings.

FIG. 4 and FIG. 5 show the construction of a conventional refrigerator operation control device and the current change of the compressor motor during operation. In FIG. 1, 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 on a cooler, and a predetermined amount of frost is not detected. For example, the defrosting start detecting means 4 for outputting a defrosting start signal is a defrosting end 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 are input terminals I ₀ , I ₁ , I ₂ , I ₃ , output terminal O ₀ ,
Has O ₁ . Then, the inputs from the in-compartment temperature detecting means 1 and the set temperature detecting means are compared, and the rotation speed of the compressor 6 is determined according to the temperature of both. For example, when the inside temperature <set temperature, the compressor is stopped, when the inside temperature> set temperature, the compressor 6 is operated at a high rotation speed, and when the inside temperature = set temperature, the compressor 6 is turned down. It is decided to operate by the number and 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. A relay 8 has a contact 8'and turns on / off the contact 8'by the output of the control means 4 to turn on / off the defrosting heater 9.

In such a configuration, considering that the refrigerator is first turned on, the inside of the refrigerator is the same as the outside temperature,
The temperature inside the chamber> the set temperature and the control means 5 controls the compressor 6
Decides to drive at high rpm. Therefore, the compressor operates at a high rotation speed. The change in the motor current of the compressor 6 at this time is shown in FIG. That is, T ₃
The motor current decreases after the peak value A ₃ of the motor current reaches the point ₃ after the elapse of time.

Further, at the time of startup after the completion of defrosting, the temperature inside the refrigerator is higher than the set temperature due to the heating due to defrosting and the operation stop of the compressor during the defrosting time, and the control means 5 operates the compressor 6 at a high rotation speed. Decide that. Therefore, the change in the motor current of the compressor 6 becomes a peak value A ₄ point of the motor current after T ₄ hours, and then the motor current decreases.

Will be described the difference between time T _3, T ₄ to reach the motor current peak point A _3, A _4. When the refrigerator is turned on for the first time, it is in a so-called "sleeping" state in which the refrigerant gas is dissolved in the oil in the compressor 6, and the oil is separated from the refrigerant gas by the operation of the compressor 6 at the start of sleeping. At the end, the load on the compressor 6 becomes maximum and reaches the current peak point A ₃ after T ₃ hours.

At the time of start-up after the completion of defrosting, the above-mentioned oil and refrigerant gas have already been separated, and when the compressor 6 operates and the refrigerant gas begins to flow into the heated heat exchanger (not shown) after defrosting. The load on the compressor 6 becomes maximum. Therefore, at the time of start-up when the power is turned on, the peak of the load on the compressor 6 is longer for the time for separating the oil and the refrigerant gas in the compressor 6 than at the time of start-up after the completion of defrosting. The relationship of ₃ > T ₄ is established.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above configuration, a very large current flows at points A ₃ and A ₄ , and this current flows, and an element such as a transistor capable of withstanding this current. Had to be used for the operation control means 7, and there was a problem that it became expensive.

Furthermore, since the peak loads A ₃ and A ₄ are reached while the compressor 6 continues to operate at a high rotation speed at startup, a severe condition of high rotation speed and high load is generated in the mechanical portion of the compressor 6 6 has a problem that reliability is lowered.

In view of the above problems, the present invention reduces the current peak value, makes elements such as transistors used for the operation control means small in capacity, and reduces the cost, as well as a high rotation speed and a high load for the compressor. It is an object of the present invention to provide a refrigerator operation control device capable of avoiding the above and improving the reliability of the mechanical part of the compressor. Means for Solving the Problems In order to solve the above problems, the refrigerator operation control of the present invention The device operates a timer from the start of the compressor,
The timer operates the compressor at a predetermined rotation speed for a certain period of time.

With the above-described configuration, the present invention starts the compressor at an intermediate rotation speed of about commercial power supply, and the timer overwhelms the peak load of the compressor while maintaining the intermediate rotation speed for a certain time. Therefore, the peak current value of the compressor can be kept low as a whole, and the peak load, which became low at the intermediate speed, can be alleviated, so the mechanical part of the compressor is not overloaded. Can be reduced.

Embodiment An operation control apparatus for a refrigerator according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an operation control device for a refrigerator according to an embodiment of the present invention. In FIG. 1, the inside temperature detection means 1, the set temperature detection means 2, the defrost start detection means 3, the defrost end detection means 4, the control means
5, the compressor 6, the operation control means 7, the relay 8 and the heater 9 are the same as those of the conventional example, and therefore detailed description thereof will be omitted. Reference numeral 10 denotes a first timer which starts its operation when the compressor 6 is started when the power is turned on, and outputs an output after a lapse of a certain time. Due to this output, the control output stage 5 causes the first timer 10
During operation, it is decided to operate the compressor 6 at an intermediate rotation speed of a high rotation speed and a low rotation speed, and an output is sent to the operation control means 7, and the operation control means 7 rotates the compressor 6 at an intermediate rotation speed. It is driven by a number. Further, 11 is a second timer which starts its operation when the compressor 6 is started after the defrosting is completed, and operates for a fixed time shorter than the first timer,
During the operation of the second timer, the control means 5 determines to operate the compressor 6 at an intermediate rotation speed, sends an output to the operation control device 7, and operates the compressor 6 at an intermediate rotation speed. Is.

The operation of the refrigerator operation controller configured as described above will be described below with reference to FIG.

In FIG. 2, it is detected that the power is turned on in one step, and the first timer 10 is started in two steps. Next, in 3 steps, it is judged whether or not the first timer 10 has reached the set time, and if it is the set time, the operation proceeds to 6 steps, and if it is not the set time, the operation proceeds to 4 steps. In step 4, the control means 5 outputs the intermediate rotation speed (3600 rpm) to the operation control means 7 to operate the compressor 6 at the intermediate rotation speed. Next, in step 5, the signal from the defrosting start detecting means 3 is input to determine whether defrosting has started. If defrosting has not started, the process returns to step 3 and the above operation is repeated. Then, in three steps, the first
When the timer 10 has reached the set time, the operation proceeds to step 6, and in step 6, the in-compartment temperature detected by the in-compartment temperature detecting means 1 is input from the input terminal 10. Next, in step 7, the set temperature detected by the set temperature detecting means 2 is input from the input terminal I ₁ . Next, in 8 steps, the internal temperature input in 6 steps is compared with the set temperature input in 7 steps, the rotation speed of the compressor 6 is determined in 9 steps, and the operation control means 7 is output from the output terminal O _1. Output to. At this time, the operation control means 7 operates the compressor 6 at the determined rotation speed. For example, when the internal temperature is higher than the set temperature, the operating speed of the compressor 6 is 5400 rpm, and when the internal temperature is the set temperature, the operating frequency of the compressor 6 is 1800 rpm,
When the internal temperature <the set temperature, the operating frequency of the compressor 6 is set to 0 rpm, and when it is 0 rpm, the compressor 6 is turned off. Next, when defrosting is started in 5 steps, proceed to step 10 and change the operating frequency of the compressor 6 in 10 steps.
Set to ₀ rpm (OFF) and output to operation control means from output terminal O ₀ . Next, in step 11, 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, in 12 steps, the signal of the defrosting completion detecting means 4 is input, and it is judged whether or not there is an output of the defrosting completion detecting means 4. If there is no output, the procedure returns to step 12 and the defrosting completion detecting means 4 again. Input the signal. If there is an output, the operation proceeds to step 13 to turn off the heater 9 and finish the defrosting. Next, in 14 steps, the second timer 11 is started, returning to 3 steps, it is judged whether or not this second timer 11 is finished. If it is finished, proceed to 6 steps, and if it is not finished, 4
Proceeding to step, the compressor 6 is operated at the intermediate speed as described above in step 4. Then, this operation is continued until the second timer 11 ends in the judgment of three steps.

In this way, when the compressor 6 is started when the power is turned on, the control means 5 determines to operate the compressor 6 at the intermediate rotation speed (3600 rpm), so that the motor current increases as shown in FIG. Make a change. At this time, the set time of the first timer 10 is set to a time T ₁ sufficiently exceeding the time T ₃ until the current peak value (shown by the broken line) in the related art (this time can be obtained by experiments, etc.). By doing so, the motor current can be suppressed to the peak value A ₁ corresponding to the intermediate speed operation by operating at the intermediate speed. Furthermore, after the current peak A _{1 is} passed, the maximum rotation speed (5400 rpm) will be reached for the first time by comparing the internal temperature detection means 1 and the set temperature detection means 2. Therefore, the increase in the current at this time is caused by the conventional peak value.
It becomes A ₃ or less, thus it is possible to suppress the peak of the motor current.

Next, even when the compressor 6 is started after defrosting, the second timer 11 is set to the time T ₂ that sufficiently exceeds the conventional current peak value A ₄ in the same manner as when the power is turned on.
The compressor 6 can suppress the current peak value by reaching the current peak value A ₂ at the motor current value corresponding to the intermediate rotation speed.

The time to reach this current peak value is almost constant in one system, and for the reason explained in the conventional example, the sleep start at power-on is longer than the start after defrosting. set time T ₁ of the first timer 10, the set time T ₂ of the second timer 11 may be determined to a predetermined value serving as a T _1> T ₂ by the system.

As described above, according to the present embodiment, the first timer 10 and the second timer 10
The current peak value can be reduced by setting the timer 11 to the times T ₁ and T ₂ that are sufficiently longer than the time until the current peak values A ₁ and A ₂ are reached, and elements such as transistors used for the operation control means 7 can be The capacity can be made small, and the configuration of the operation control means 7 can be made inexpensive. Further, the mechanical part of the compressor 6 (for example, sliding parts such as bearings, pistons and cylinders, not shown) receives a peak load which is low at the intermediate speed, so that the mechanical part is burdened. Can be reduced and the reliability of the compressor 6 can be improved.

In the embodiment, both the first timer 10 and the second timer 11 are operated, but the first timer 10 or the second timer 11 is operated.
The current peak value may be reduced by operating one of the timers 11, which is unique to one system, whichever has a larger peak value of the motor current.

As described above, according to the present invention, when the compressor is started, the compressor is controlled to operate at a predetermined rotation speed for a certain period of time. Therefore, the capacity of an element such as a transistor used in the operation control means is small. Therefore, it is possible to configure an inexpensive operation control means. Further, the reliability of the compressor can be improved.

[Brief description of drawings]

1 is a block diagram of an operation control device for a refrigerator showing an embodiment of the present invention, FIG. 2 is a flowchart of FIG. 1, and FIG.
FIG. 4 is a current characteristic diagram showing a change in motor current when the operation control device of the present invention is used, FIG. 4 is a configuration diagram showing a configuration of a conventional refrigerator operation control device, and FIG. 5 is a power supply by a conventional control method. FIG. 4 is a current characteristic diagram showing a change in motor current after turning on. 1 ... internal temperature detecting means, 2 ... set temperature detecting means, 5
...... Control means, 7 ...... Operation control means, 10 ...... First timer, 11 ...... Second timer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Miura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-60-226686 (JP, A) JP-A-60-69446 (JP, A)

Claims (2)

[Claims] Claim: What is claimed is: 1. An inside temperature detecting means for detecting the inside temperature,
From the set temperature detecting means for detecting the set temperature in the refrigerator, the timer which starts the operation simultaneously with the start of the compressor and outputs the output after a lapse of a certain time, the inside temperature detecting means, the set temperature detecting means and the timer Is input to the control means for determining the rotation speed of the compressor, and operation control means for operating the compressor at the rotation speed determined by the control means. A refrigerator operation control device that controls to operate this compressor by a number. 2. The timer is divided into a first timer that starts operation when the compressor is started when the power is turned on, and a second timer that starts operation when the compressor starts after defrosting is completed. The refrigerator operation control device according to claim 1, wherein one or both of them are operated.