JPS6317373A - Controller for 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 (a) Field of Industrial Application The present invention relates to a control device for a refrigerator that controls the temperature inside a storage chamber by adjusting the rotation speed of a compressor.

(B) Conventional technology Conventionally, in this type of refrigerator, upper and lower temperature limits are set above and below the set temperature in the storage room, and the compressor of the refrigeration cycle is started at the upper temperature limit and stopped at the lower temperature limit for storage. A so-called 0N-OFF control method has been adopted in which the indoor temperature is set to an average temperature. In this method, in order to prevent frequent startup and stoppage of the compressor, the interval between the upper limit temperature and the lower limit temperature is not narrower than a certain value, and therefore the storage room temperature is constantly fluctuating between the upper limit temperature and the lower limit temperature. Therefore, there are limits to the ability to control the quality of food products, etc.

In order to solve this problem, in recent years, for example,
It is conceivable to use a variable speed compressor to control the temperature inside the storage chamber, as disclosed in Japanese Patent No. 263070, and with this, fluctuations in the temperature inside the storage chamber can be reduced as much as possible. In addition, in order to preserve foods in a frozen state, a rapid freezing function is installed, and the compressor is set at maximum rotation speed for a certain period of time to increase cooling capacity, thereby minimizing tissue destruction of foods. .

(c) Problems to be solved by the invention In such a configuration, the cooling capacity of the refrigeration cycle increases as the compressor reaches its maximum rotation speed, and a good rapid cooling function is exhibited. Due to the rotation speed, depending on the amount and type of food, unnecessary forced operation may be performed, resulting in labor costs for electricity.

(2) Means for Solving the Problems The present invention has been made to solve the above problems, and the present invention will be described in detail below with reference to Examples.

The micro CPU (30) of the control electric circuit (24) changes the operating frequency of the electric compressor (20) when the temperature (T, ) of the freezer compartment (F) is high and the difference from the set temperature (T, ) is large. 120H2, and as it approaches the set temperature (T,), it becomes 90H2.
The frequency is gradually decreased from 1 to 60H2 to 3082. As a result, the temperature (TF) of the freezer compartment (F) is controlled to the set temperature (T, ). When the rapid cooling switch (34) is pressed, the micro CPU (30) forcibly lowers the set temperature (T,) to -40°C for 150 minutes.The set temperature (T,) normally goes up to -23°C. Therefore, this lowering causes the electric compressor (20) to shift to high speed rotation.

(E) Function According to the present invention, the rotation speed of the electric IE compressor (20) is increased by operating the rapid cooling switch (34);
This forced operation is not continued for 150 minutes, but the set temperature (T,) continues to be lowered, so the operating frequency is also reduced in this case as the temperature decreases.

(F) Embodiment An embodiment will be explained with reference to the drawings. FIG. 2 shows a refrigerator-freezer (1) as an example. (2) is a heat insulating box body, and its interior is divided into upper and lower parts by a heat insulating partition wall (3), with a freezer compartment (F) serving as the first compartment in the upper part and a refrigerator compartment (R) serving as the second compartment in the lower part. The division has been completely formed. (
6) and (7) are heat insulating doors that separately open and close the front openings of the freezer compartment (F) and the refrigerator compartment (R). A cooling chamber (8) is formed within the partition wall (3),
A cooler (10) included in the refrigeration cycle is housed inside. A duct (11) that communicates with the cooling chamber (8) and both chambers (F) and (R) is formed behind the cooler (10), and a blower (
At step 12), air cooled by the cooler (10), that is, cold air, is sucked in and forcibly blown out into the duct (11). (
12M) is a motor that drives the blower (12). The cold air blown into the duct (11) is blown into the freezing compartment (F) through the discharge port (14) and into the refrigerator compartment (R) through the discharge port (15). (17) is the discharge port (15)
A gas-filled damper thermostat installed in the refrigerator compartment (R) to open and close the discharge port (15) with a baffle plate (18) based on the temperature in the refrigerator compartment (R). ) is controlled to an average of +5°C between +7°C and +3°C. (19) is a heat insulating cover for the damper thermostat (17). Further, (20) is an electric compressor installed in the machine room (21) at the bottom of the refrigerator-freezer (1) and included in the refrigeration cycle. Inside the machine room (21), a condenser (22), which is also included in the refrigeration cycle, and a blower (23) for cooling the condenser (22) and the aforementioned electric compressor (20) can be installed. Note that (5>) is an operation panel attached to the front surface of the door (6).

FIG. 1 shows in block diagram form the control electrical circuit (24) of the present invention. (25) is a microcomputer, A/
It has the functions of a D conversion section (26) (7) (28) and (29) and a micro CPU (30). (31) is a sensor that detects the temperature (TF) of the freezer compartment (F),
Micro CPU (30) via A/D converter (26)
is input. (32> is the temperature inside the refrigerator compartment (R) (T1
1), and its output is similarly A/
The data can be input to the micro CPU (30) via the D converter (27). (33) is a setting switch for setting the temperature of the freezer compartment (F), which is input to the micro CPU (30) via the A/D converter (28). (34) is the freezer compartment (F)
Rapid cooling switch to start rapid cooling operation of
It is arranged on the operation panel (5) together with the switch (33). The output of the micro CPU (30) is sent to the D/A converter (36).
) and then the inverter circuit (37) connects the electric compressor <2
Controls the rotation speed of the three-phase synchronous motor (20M) for driving 0).

In addition, the output of the micro CPU (30) is sent to the D/A converter (3).
8) and then the motor (12M) by the driver circuit (39).
). Furthermore, the output of the micro CPU (30) is input to a driver circuit (41) via a D/A converter (40), and this driver circuit (41) outputs the output from the display section (4).
2) to display the operating frequency of the 1E dynamic ratio compression (20).

In addition, the output of the micro CPU (30) is sent to the D/A converter (
The driver circuit (44) via the display unit (43)
5) to control the temperature (
Tc (T1) etc. are displayed.

FIG. 3 shows a refrigerant circuit diagram of the refrigeration cycle of the refrigerator-freezer (1). The high-temperature, high-pressure refrigerant discharged from the electric compressor (20) radiates heat in the condenser (22), is reduced in pressure in the pressure reducer (47), and flows into the cooler (10), where it evaporates and releases heat of vaporization. It is taken from the surrounding area and then sucked into the electric compressor 20).

Next, FIG. 5 shows the operation panel (5). control panel(
5) includes a display section (42) composed of four light emitting diodes arranged in parallel, and a plurality of light emitting diodes (50) (51).
(52) (53) (54) (55) (56) (57)
Freezer compartment temperature display section (58), which is arranged in parallel, and refrigerator compartment temperature display section (59), which is also composed of a plurality of light emitting diodes.
and setting switch (33) and quick cooling switch (34)
will be placed. The above-mentioned display section (45) is formed by the freezing room temperature display section (58) and the refrigerator room temperature display section (59). The display section (42) shows the motor (2) of the electric compressor (20).
30!1□, 60H2,9 as the operating frequency of 0M>
0H2, 120) A light emitting diode is arranged corresponding to the IZ display, and the refrigerator compartment temperature display section (59) is located in the refrigerator compartment (R
) as temperature (TR) and +9°C to -11°C
Light emitting diodes are arranged to correspond to the display at 2°C intervals. The freezer compartment temperature display section (58) also has a light emitting diode (50) (
51), (52), (53), (54), (55), and (56) are arranged, and a light emitting diode (57) is further arranged to display the above-mentioned rapid cooling operation. Furthermore, at least light emitting diodes (51) (52) (53) (54
) (55), (56), and (57) are constructed of diode elements (LEDs) that emit two colors of light as shown in FIG. The diode element (LED) is composed of a green light emitting diode (Dl) and a red light emitting diode (Dl) with one end commonly grounded and the other end connected to the driver (44), and the diode (Dl) is energized. The diode element (LED) emits green light, and when the diode (Dl) is energized, it emits red light.

Next, referring to the graph showing the relationship between the operating frequency of the electric compressor (20) and the temperature (TF) of the freezer compartment (F) in FIG. 4, the micro CPU ( 30
) operation is explained. If the temperature (TF) of the freezer compartment (F) set by the setting switch (33) is (T,), the operating frequency is normally changed as shown by the solid line in the figure.

That is, when the temperature (TF) sensed by the ζ sensor <31) is higher than the current high < (T, +4), the inverter circuit sets the operating frequency of the electric compressor (20) to the maximum rotation speed of 120112. As a result, the temperature (T, ) of the freezer compartment (F) rapidly decreases. This changes (TF) to (
T, +4), the current state is maintained for, for example, 3 minutes from that point, and then the operating frequency is lowered to 90H2. As a result, the rate of decrease in temperature (T,〉) slows down.When (IF) further reaches (TS+2) from this state, the current state is maintained for 3 minutes, and then the frequency is increased to 60Hz.
It will be lowered to . This further slows down the rate of decrease in temperature (TF). After that, when (T5) is reached, the operating frequency is similarly lowered to 30H2 3 minutes after that point.

In this way, the temperature (T,) approaches the set temperature (T, ), and so-called overshoot is reduced.

Conversely, when the operating frequency is 30H2 and the temperature (T) rises and reaches (T,), the current state is maintained for 3 minutes from that point, and then the temperature is increased to 60H2.
After reaching 2), accelerate to 90H2 3 minutes after reaching ('rs'2). Similarly, 3 minutes after reaching (TS"4), increase to 120H2. In this way, the temperature (TF) of the micro CPU (30>) is (T,
+4), (Ts”2), (Is), a command to change the operating frequency is generated internally, but from that point on, the frequency will not be changed for 3 minutes as mentioned above. The same is true even if the frequency to be changed is corrected within 3 minutes after reaching either (IS+4>(TS+2)(TS)).This changes the frequency to the corrected frequency. Frequent changes in the operating frequency of the motor (20M) can be prevented, and deterioration of the motor (20M) and expansion of noise can be prevented.

Ideally, the capacity of each device should be set so that the temperature (T) can be maintained at the set temperature (T5) by operating at 30H2, but the load in the freezer compartment (F) is small, and the refrigerator-freezer (
1) In a situation where the ambient temperature is low, the temperature (IF) decreases even when operating at 30 hours. In this case, the motor (20M) is stopped when it reaches (IS-2). This prevents overcooling in the freezer compartment (F). Then temperature (T)
rises and reaches (rs-z>), it remains stopped for 5 minutes from that point, and then the electric compressor (20) is started and set to 30H2. □This causes the electric compressor (20 ) to prevent deterioration of the electric compressor (2).
Since the operating frequency of 0) is successively changed, the temperature (TF) is substantially stably controlled to the set temperature (TS) (for example, -18°C). Note that the blower (12) is continuously operated while the electric compressor (20) is operating. Furthermore, the frequency change does not always take the steps shown in Figure 4; for example, the current temperature (T
If F) suddenly rises from (T, ) to (TS+4) due to reasons such as the door (6) being left open for a long period of time, the frequency change command is issued inside the micro CPU (30) in this case as well. Three minutes after the output, the operating frequency is increased to 120H2.

The micro CPU (30) uses a driver (41) to display a display section (42) corresponding to the operating frequency of the electric compressor (20).
) lights up to display the current operating frequency. The temperature of the refrigerator compartment (R), which is controlled by the damper thermostat (17), is also controlled by the micro CPU (30).
is displayed by lighting the corresponding light emitting diode of the refrigerator compartment temperature display section (59) of the display section (45) using the driver (44) based on the sensor (32).

On the other hand, to explain the temperature display and setting operation of the freezer compartment (F), the temperature (TF) of the freezer compartment (F) ranges from -12°C to -12°C.
It is displayed in 2°C intervals up to 2°C, and when it is higher than -12°C, it is displayed all at once as high temperature. That is, the current temperature is 118°C
When this is the case, the driver (44) energizes only the green light emitting diode (Dl) of the light emitting diode (54) corresponding to -18°C in the freezer compartment temperature display section (58) of the display section (45), and emits light. The diode (54) is made to emit green light. As a result, the current freezer temperature (T,) is displayed in green. To set the temperature, press the setting switch (33) -
Press twice to change the currently set temperature (T,), for example -1
If the temperature is 6° C., the red light emitting diode (D2) of the light emitting diode (53) will emit light. As a result, the set temperature (T,) is displayed in red on the freezer compartment temperature display section (58).

At this time, the current temperature is turned off. Next, set temperature (T,)
When changing the temperature, the set temperature (T, ) is shifted by pressing the setting switch (33) successively, and at the same time, the light emitting diode that lights up in red changes. Two seconds after the last press of the switch (33), the display returns to the current temperature. In this way, you can set the set temperature from -12°C to -23°C while checking it, but since - 2°C is assigned to each light emitting diode, the display is at 2°C intervals.
The settings themselves can be made in 1°C increments. This makes it possible to reduce the number of light emitting diodes. The same applies to the display of the current temperature (TF).

Next, the rapid cooling operation of the freezer compartment (F) will be explained. When the rapid cooling switch (34) is pressed completely at any time, the signal is input to the micro CPU (30), and the micro CPU (30) adjusts the set temperature (T, ) of the freezer compartment (F).
is the minimum set temperature during normal cooling operation, which is the above-mentioned 12
Set the switch (34
) is pushed down forcibly for 150 minutes. At this time, the operating frequency and temperature (T
, ) is shown by the broken line in FIG. During this rapid cooling operation, when the temperature (T, ) is higher than the set temperature (T, ) by 18℃ (Ts+18), the operating frequency is changed to 12 (LH
z, when it reaches (T, +18), reduce the frequency to 90H2 3 minutes after that point, maintain it until it reaches (T, +4), and when it reaches (Ts”4), reduce the frequency 3 minutes after that point. Further lower the temperature to 60 tons.After that, the temperature (TF
Micro CP to maintain 60H unless ) increases.
U(30) operates. That is, the current set temperature (T,) is -18°C, and the freezer compartment (F) temperature (IF) is also -
If you press the rapid cooling switch (34) when the temperature is 18°C, the set temperature (T,) will be forcibly changed to -40°C, so (T,) will be lower than -22°C which is (Ts”18). Therefore, the micro CPU (30) lowers the operating frequency to 1.
A command to set the frequency to 20H2 is issued, and three minutes after that point, the frequency is increased to 120H. As a result, the inside of the freezer compartment (F) is strongly cooled, and the temperature (T, ) rapidly decreases. After that, when the temperature reaches -22°C, 3
After a minute, the frequency is set to 90H7. When the temperature (I,) further decreases and reaches -36℃, which is (TS+4), the operating frequency will be lowered to 60H, 3 minutes after that point.In this way, the inside of the freezer compartment (F) Since the food is rapidly cooled, tissue destruction can be minimized during cryopreservation of food.Also, the maximum rotation speed of the electric compressor (20) is maintained throughout the rapid cooling operation. rather than
As with normal temperature control, the operating frequency is lowered as the temperature (T) decreases, so unnecessary high-speed operation of the electric compressor @ (20) at extremely low temperatures is eliminated, contributing to energy savings. After 150 minutes have elapsed, the set temperature (T, ) returns to the value before the switch (34) was pressed, and thereafter normal operation control is resumed.

When the quick cooling switch (34) is pressed, the microcomputer (30) uses the driver (44) to energize the diode (D2) of the light emitting diode (57) to emit red light, thereby informing the user that the quick cooling operation has started. to be displayed. After that, when the temperature in the freezer (F) drops to -25°C, which is lower than the minimum set temperature of -23°C, switch the energized diode to (Dl) and turn the light emitting diode (57) green. It emits light to notify the user that rapid cooling has progressed and the temperature (TF) in the freezer compartment (F) has become extremely low.

(G) Effects of the Invention According to the present invention, as described above, the temperature is controlled by the rotation speed of the compressor, so that the temperature is controlled by 31ff compared to the conventional one.
Compared to ON-OF type control, it is possible to stably adjust the temperature inside the storage chamber. In addition, by using a configuration in which the set temperature is forcibly lowered by operating the rapid cooling switch, the rotation speed of the compressor increases, achieving rapid cooling in the storage chamber, and in that case, the temperature also decreases. Since the rotational speed is accordingly reduced, unnecessary high-speed operation of the compressor is prevented, contributing to energy savings.

[Brief explanation of drawings]

Each figure shows an embodiment of the present invention. Figure 1 is a block diagram of a control electric circuit, Figure 2 is a side sectional view of a refrigerator-freezer,
Figure 3 is a refrigerant circuit diagram, Figure 4 is a diagram showing the relationship between the operating frequency of the electric compressor and freezer compartment temperature, Figure 5 is a front view of the operation panel, and Figure 6 is a circuit diagram of the two-color light emitting diode. be. (F)...Freezing room, (20)...Electric compressor,
(24)...Control electric circuit, (30)...Micro CPU, (37)...Inverter circuit, (
34)...Rapid cooling switch. Applicant Sanyo Electric Co., Ltd. and one other agent Patent attorney Takuji Nishino and one other person Figure 3 Figure 6 o o o o. Vomit ≦7 Keifuzo Figure 5 34 jJ

Claims (1)

[Claims] 1. When the temperature inside the storage room is high and the difference from the set value is large, the compressor is rotated at high speed, and as the temperature decreases and approaches the set temperature, the rotation speed is reduced to control the temperature inside the storage room. A control device for a refrigerator, characterized in that the set temperature is forcibly set to a predetermined low value for a certain period of time by a signal from a rapid cooling switch.