JPH06273029A - Refrigerator - Google Patents

Abstract

PURPOSE:To reduce a driving power of a compressor and reduce its vibration and noise or the like and embody less noiseless operation by controlling the output frequency of an inverter circuit so that it may be lower than a commer cial power source frequency. CONSTITUTION:Voltage is applied to a compressor 3 by way of an inverter circuit 9 from a commercial power source 8. The drive of the compressor 3 is controlled with the output frequency of the inverter circuit 9. The inverter circuit 9 rectifies the AC voltage of the commercial power source 8 and applies variable DC voltage to the compressor 3 with an electric signal transmitted from a microcomputer 2 so that a specified output frequency may be available. When a quiet mode setting switch 11 is turned ON, a maximum output frequency determination circuit 17 is arranged to decide that the miximum value of output frequency of the inverter circuit 9 is lower than a commercial power source frequency produced from the commercial power source. Furthermore, it is designed so that no resonance occurs between the vibration frequency of the compressor 3 and the output frequency of the inverter circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator provided with an inverter circuit for performing variable speed control of a compressor.

[0002]

2. Description of the Related Art Conventionally, a refrigerator has a compressor, a condenser,
A refrigeration cycle in which a pressure reducer, an evaporator, etc. are in communication, and an AC power supply that supplies drive power to the compressor,
By controlling the output frequency of the inverter circuit according to the load, it is possible to operate the compressor efficiently and save energy in the driving force of the refrigerator.

Zone control is usually employed to control the output frequency of the inverter circuit. In this zone control, the above loads are classified by band (zone),
By setting different output frequencies of the inverter circuit in each zone, the optimal driving force is given to the compressor. For example, when the load is set to the inside temperature, the zone is set inside the inside. If the output frequency is set for each temperature difference as the difference between the temperature and the actually measured temperature, in the zone where the temperature difference is large, the output frequency is set high to improve the driving force of the compressor and the zone where the temperature difference is small. Then, the output frequency is set low to reduce the driving force of the compressor.

However, in the above zone control, the output frequency of the inverter circuit approaches the set temperature while repeating ON / OFF hunting, so that the output frequency is turned ON in a quiet state such as at night.・
The OFF hunting noise is offensive to the ear, which makes it difficult to achieve quietness.

Therefore, for example, Japanese Patent Application Laid-Open No. 2-93237 discloses a refrigerator in which a plurality of output frequency patterns to be set in a zone are prepared and the zone control is adopted to switch the patterns according to the load and environment. It is disclosed. In the above pattern, a zone pattern is set such that the output frequency of the inverter circuit changes slowly. By using this zone pattern, the refrigerator is made quiet.

[0006]

However, in the above-described zone pattern which realizes the noise reduction of the refrigerator, the output frequency of the inverter circuit is controlled at a slow change rate, so that it is set in the refrigerator, for example. It takes time to approach the temperature, resulting in a problem that the refrigerator cannot be operated efficiently and energy efficiency is reduced.

Further, in a refrigerator using an inverter circuit, the voltage applied to the compressor contains a high frequency component and becomes a source of vibration / noise, and the relationship between the vibration / noise and the output frequency makes the output frequency higher. For example, the rotational speed of the compressor motor increases and the torque also increases, which causes vibration and noise to increase. Therefore, when the output frequency of the inverter circuit is set higher than the commercial power supply frequency, it is difficult to realize noise reduction.

Further, in zone control of the output frequency of the inverter circuit, the compressor is turned on / off by hunting.
A start-up sound at the time of starting, and a mechanical periodic sound when the output frequency of the inverter circuit and the resonance frequency of the compressor overlap, which also makes it difficult to realize quietness. The present invention has been made in view of the above problems, and an object thereof is to provide a refrigerator having high energy efficiency and capable of achieving noise reduction.

[0009]

According to a first aspect of the present invention, there is provided a refrigerator in which a compressor, a condenser, a decompressor, and an evaporator are communicated with each other, and an inverter for driving and controlling the compressor according to an output frequency. A silent mode setting means for setting a silent mode, and an output frequency control means for controlling the output frequency to be lower than the commercial power supply frequency when the silent mode is set by the silent mode setting means. And are provided.

The refrigerator according to the second aspect of the present invention is the refrigerator according to the first aspect.
In the refrigerator described above, a nighttime detection means for detecting nighttime, a timekeeping means for counting time from the time when nighttime is detected by the nighttime detection means, and an opening / closing detection means for detecting opening / closing of the refrigerator door at night are provided, and When night time is detected by the night time detection means, and when it is detected by the time measurement means and the opening / closing detection means that the door is not opened / closed for a predetermined time, a silent mode switching control means is provided for controlling to switch to the silent mode. It is characterized by being present.

The refrigerator according to the third aspect of the present invention is the refrigerator according to the second aspect.
In the refrigerator described above, the inside temperature detecting means for detecting the temperature inside the refrigerator, the inside temperature setting means for setting the inside temperature to a desired temperature, and the above according to the difference between the detected temperature and the set temperature inside the refrigerator. Output frequency determining means for determining the output frequency of the inverter circuit, and if the silent mode is set by the silent mode setting means or night time is detected by the night detecting means, the output determined by the output frequency determining means It is characterized in that temperature difference correcting means for correcting the hysteresis temperature difference corresponding to the frequency is expanded.

A refrigerator according to a fourth aspect of the present invention is the refrigerator according to the first, second or third aspect, wherein the compressor includes vibration detecting means for detecting vibration of the compressor, and compression detected by the vibration detecting means. Output frequency correction means for correcting the output frequency of the inverter circuit so as to slightly shift it so as not to resonate with the vibration frequency of the machine is provided.

[0013]

According to the structure of claim 1, the inverter circuit for driving and controlling the compressor by the output frequency, the silent mode setting means for setting the silent mode, and the silent mode set by the silent mode setting means By providing the output frequency control means for controlling the output frequency to be lower than the input frequency to the inverter circuit, when the silent mode is set, the output frequency of the inverter circuit by the output frequency control means, Since the input frequency of the inverter circuit can be made lower than, for example, the frequency of the commercial power supply, the driving force of the compressor can be reduced, and as a result, the vibration and noise of the compressor can be reduced and the noise can be reduced. Can be realized.

According to the structure of claim 2, night is detected,
The silent mode switching control means for controlling to switch to the silent mode when the refrigerator door is not opened / closed for a predetermined period of time is provided, so that the silent operation can be realized at night and the power of the compressor at night can be realized. The consumption amount can be reduced, the refrigerator can be efficiently driven, and as a result, the energy efficiency of the refrigerator can be improved.

According to the third aspect of the invention, when the silent mode is set or night is detected, the temperature difference correction means causes the width of the hysteresis temperature difference corresponding to the output frequency determined by the output frequency determination means. Can be extended, the ON / OFF hunting interval of the compressor at this output frequency can be lengthened, the number of ON / OFF hunting can be reduced, and as a result, the noise generated when the compressor is turned ON / OFF can be reduced. It is possible to reduce the noise, and it is possible to achieve the noise reduction.

According to the structure of claim 4, in the compressor, the vibration detecting means for detecting the vibration of the compressor and the frequency of the vibration of the compressor detected by the vibration detecting means do not resonate with the inverter circuit of the inverter circuit. By providing the output frequency correcting means for correcting so as to slightly shift the output frequency, the vibration caused by the resonance between the vibration frequency in the compressor driving means and the output frequency in the inverter circuit, which has conventionally occurred,
It is possible to eliminate noise and achieve quietness.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

As shown in FIG. 1, the refrigerator according to the present embodiment comprises a refrigeration cycle 1 and a microcomputer 2 as a control means for controlling the refrigeration cycle 1.

The refrigeration cycle 1 comprises a compressor 3, a condenser 4, a pressure reducer 5 and an evaporator 6 which are communicated with each other, and a fan 7 for circulating the cold air generated by the refrigeration cycle 1 in the refrigerator is provided. ing.

Of these, a voltage is applied to the compressor 3 from a commercial power source 8 via an inverter circuit 9, and the compressor 3 is drive-controlled by the output frequency of the inverter circuit 9.

The inverter circuit 9 rectifies the AC voltage of the commercial power source 8 and applies a variable DC voltage to the compressor 3 in accordance with a control signal from the microcomputer 2 so as to make it have a predetermined output frequency. . Zone control is generally adopted as a control means for controlling the output frequency of the inverter circuit 9. In this zone control, for example, as shown in FIG. 2, zones A to H are created in advance based on the difference between the set temperature inside the refrigerator and the detected temperature inside the refrigerator, and the actual temperature inside the refrigerator and the inside temperature are set. Any zone from A to H is determined by the difference with the temperature, and the inverter circuit 9 is controlled by the output frequency in the corresponding zone. That is, the temperature is approached to the set temperature while the capacity is controlled by the output frequency set in the zone. For example, in the A zone where the temperature difference is large, the output frequency is set high, and the driving force of the compressor 3 is increased to approach the set temperature, while in the F and G zones where the temperature difference is small, the output frequency is set. Is set to a low value, and the driving force of the compressor 3 is reduced to approach the set temperature.

On the other hand, the microcomputer 2 as the control means is
As shown in FIG. 1, a vibration sensor 10 as a vibration detecting means for detecting the vibration of a refrigerator, and a silent mode setting switch 1 as a silent mode setting means for switching to a silent mode.
1, an inside temperature setting switch 12 as an inside temperature setting means for setting the temperature inside the refrigerator, an inside temperature sensor 13 as an inside temperature detecting means for detecting the temperature inside the refrigerator, a timer 14 as a time measuring means, A nighttime detection sensor 15 as nighttime detection means for detecting nighttime and a door opening / closing detection sensor 4 as open / closed detection means for detecting opening / closing of a refrigerator door.
0 is connected.

Further, the microcomputer 2 is provided with the vibration sensor 1 described above.
A resonance frequency detecting circuit 16 for detecting a resonance frequency by a detection signal from 0, and a maximum output frequency determining means as an output frequency control means for determining a maximum value of the output frequency of the inverter circuit 9 by an output signal from the silent mode setting switch 11. Circuit 17, output frequency determining means for determining a zone by an output signal from the inside temperature setting switch 12 and an output signal from an inside temperature detecting circuit 18 for detecting the inside temperature by a detection signal from the inside temperature sensor. Zone determining circuit 19, a zone correcting circuit 20 as temperature difference correcting means for performing zone correction by an output signal from the zone determining circuit 19 and an output signal from the nighttime detection sensor 15, and the maximum output frequency determining circuit 17 And the output signal from the zone correction circuit 20 determines the output frequency of the inverter circuit 9. Inverter output frequency determining circuit 21 to a constant, the inverter circuit output frequency determining circuit 2
An output frequency correction circuit 22 that finally corrects the output frequency of the inverter circuit 9 by the output signal from 1 and the output signal from the resonance frequency detection circuit 16 is provided.

As shown in FIG. 4, the inverter circuit 9 comprises a rectifying / smoothing circuit 22, a power conversion circuit 23, a drive circuit 24, and an OR circuit 25.
Reference numeral 2 smoothes the voltage from the commercial power supply 8 to DC, and the power conversion circuit 23 applies a variable DC voltage to the DC brushless motor of the compressor 3 by switching the power transistor. The inverter circuit 9 is drive-controlled by an inverter control unit.

As shown in FIG. 4, the inverter control section includes a rotor position detection circuit 35 for detecting the rotor position of the motor 26 of the compressor 3, a rotation speed detection circuit 34 for detecting the rotation speed of the motor 26, and the motor 26. Target rotation speed determination circuit 36 for setting the target rotation speed of the motor 26, a comparison circuit 37 for comparing the rotation speed of the motor 26 detected by the rotation speed detection circuit 34 with the target rotation speed, and an output signal from the comparison circuit 37. Through the feedback control circuit 38 to P T _r 6 phase 3
3 output signal. On the other hand, the signal from the comparison circuit 37 is used as the output signal of the PWM 32 via the duty control circuit 38.

The control in the microcomputer 2 will be described below. First, the control when the silent mode of the refrigerator is selected will be described. When the silent mode setting switch 10 is turned on, the maximum output frequency determination circuit 17 causes the commercial power supply 8 to generate the maximum value of the output frequency of the inverter circuit 9. It is designed to be lower than the power supply frequency.

Next, when nighttime is detected by the nighttime detection sensor 15, the zone determined by the zone determination circuit 19 is turned on by lowering the OFF line by zone correction means as shown in FIG. OFF line width,
That is, the hysteresis temperature difference is made large, and the ON / OFF interval of the compressor 3 is made long.
Further, the time is measured by the timer 14 from the time when the night is detected, and if the door open / close detection sensor 40 determines that the door of the refrigerator is not opened / closed for a certain period of time, the silent mode is switched to, and the silent mode control described above is performed. Done.

Next, the vibration of the refrigerator is detected by the vibration sensor 10 and is output as the resonance frequency by the resonance frequency detection circuit 22. The resonance frequency and the decision output frequency which is the output signal from the inverter circuit output frequency decision circuit 21. When and are output to the output frequency correction circuit 22, it is determined whether or not they have the same frequency in the output frequency correction circuit 22, and if they are the same, the output frequencies are slightly shifted and output. It is like this.

The output frequency control of the inverter circuit 9 will be described below with reference to the flow chart shown in FIG.

First, it is determined whether or not it is at night (S
1). At this time, if it is detected that it is nighttime, the OFF line of the ON / OFF lines which are the hysteresis lines of the zone G shown in FIG. 3 is moved downward (S2). Next, it is determined whether or not the refrigerator door is opened and closed for a certain period of time (S3). If it is determined that the door has not been opened / closed for a certain period of time, the silent mode is executed (S4). And
The zone is determined by the difference between the inside temperature and the inside set temperature (S5).

On the other hand, if night is not detected in S1, S
If the door is opened and closed within a certain time in S3, the process proceeds to S5.

Next, if the zone is determined in S5, it is determined whether or not the silent mode is set (S).
6). If it is determined that the silent mode is set, the maximum value of the output frequency of the inverter circuit 9 is set to be lower than the frequency of the commercial power source 8 (S7). Then, the temporary output frequency is determined in the output frequency determination circuit (S8). If the silent mode is not set in S6, the process proceeds to S8.

Next, the vibration sensor 1 provided in the compressor 3
The vibration frequency of the compressor 3 is detected by 0, and is output as the resonance frequency in the resonance frequency detection circuit 16.
The resonance frequency and the tentative output frequency are output to the output frequency correction circuit 22, where the frequencies are compared,
It is determined whether the output frequency is the same as the resonance frequency (S
9). If it is determined that they are the same, the output frequency is corrected from the resonance frequency to the extent that it does not exceed the commercial power supply frequency, correction is performed, and the output is output to the inverter circuit 9. If the output frequency and the resonance frequency are not equal in S9, the output frequency is directly output to the inverter circuit 9.

As described above, the output frequency of the inverter circuit 9 in this refrigerator is set to the silent mode setting switch 11
When the silent mode is set by the control, the driving force of the compressor 3 can be reduced by controlling the frequency to be lower than the frequency of the commercial power source 8, so that the vibration and noise from the compressor 3 are reduced. Therefore, the entire refrigerator can be made quieter.

If the nighttime detection sensor 15 detects nighttime and the timer 14 and the door opening / closing detection sensor 40 determine that the door of the refrigerator has not been opened / closed for a certain period of time, the driving force of the compressor is reduced. However, since the silent mode is set, noise reduction due to ON / OFF hunting of the night-time compressor 3 and vibration of the motor can be achieved, and the compressor 3 can be efficiently driven at night. Therefore, energy efficiency can be improved.

Further, the vibration detecting sensor 10 for detecting the vibration of the compressor 3 detects the vibration of the compressor 3, the resonance frequency is detected from the vibration, and the resonance frequency and the output frequency of the inverter circuit 9 are output. Correction circuit 22
When the same frequency is output, the output frequency is slightly shifted and the noise is reduced due to the resonance of the compressor 3, so that the noise reduction can be realized.

Here, the PWM output from the microcomputer 2
If the output frequency is set to a frequency higher than the audible frequency, the switching sound generated from the inverter circuit 9 can be eliminated and the noise can be reduced.

[0038]

As described above, the refrigerator according to the first aspect of the present invention drives and controls the refrigeration cycle in which the compressor, the condenser, the decompressor and the evaporator communicate with each other, and the compressor according to the output frequency. A silent mode setting unit that includes an inverter circuit and sets a silent mode, and an output frequency control that controls the output frequency to be lower than the commercial power supply frequency when the silent mode is set by the silent mode setting unit. Means is provided.

Therefore, in the silent mode, the output frequency of the inverter circuit is set to be lower than the frequency from, for example, the commercial power source, which is the source of the input frequency, so that the silent operation can be realized. Has the effect.

As described above, the refrigerator according to the second aspect of the present invention includes the nighttime detecting means for detecting nighttime, and the timekeeping means for counting time from the time when nighttime is detected by the nighttime detecting means.
An opening and closing detection means for detecting opening and closing of the refrigerator door at night is provided, and the night detection means detects the night,
Further, when the time measuring means and the opening / closing detecting means detect that the door is not opened / closed for a predetermined time, a silent mode switching control means is provided for controlling to switch to the silent mode.

Therefore, there is an effect that it is possible to realize noise reduction at night and energy saving.

As described above, in the refrigerator according to the third aspect of the present invention, the inside temperature detecting means for detecting the inside temperature, the inside temperature setting means for setting the inside temperature to a desired temperature, and the inside refrigerator. And an output frequency determining means for determining the output frequency of the inverter circuit according to the difference between the detected temperature and the set temperature, and the silent mode is set by the silent mode setting means, or night by the night detecting means. Is detected, the temperature difference correction means is provided to correct the hysteresis temperature difference corresponding to the output frequency determined by the output frequency determination means.

Therefore, when the silent mode is set or when nighttime is detected, the hysteresis temperature difference corresponding to the output frequency determined by the output frequency determining means is corrected so as to be widened, whereby the compressor ON / OF
The interval of F hunting can be lengthened and the entire ON
-The number of times of OFF hunting can be reduced, and as a result, the noise generated when the compressor is turned on and off can be reduced, and noise reduction can be achieved.

As described above, in the refrigerator according to the fourth aspect of the present invention, the compressor is provided with vibration detecting means for detecting the vibration of the compressor, and the frequency of the vibration of the compressor detected by the vibration detecting means and resonance. In order not to do so, output frequency correction means for correcting the output frequency of the inverter circuit so as to be slightly shifted is provided.

Therefore, in addition to the effects of the first, second, and third aspects, the vibration frequency of the compressor and the output frequency of the inverter circuit do not resonate with each other, so that vibration and noise of the compressor can be reduced. Therefore, there is an effect that it is possible to realize the noise reduction.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram and a control block diagram of a refrigerator according to an embodiment of the present invention.

FIG. 2 is a zone control diagram showing control of output frequency of the inverter circuit in FIG.

FIG. 3 is a correction explanatory view showing a state in which correction is performed by a correction unit for zone control in FIG.

4A and 4B are a circuit diagram and a drive control block diagram of an inverter circuit in FIG.

5 is a flowchart showing control of output frequency of the inverter circuit in FIG.

[Explanation of symbols]

1 Refrigeration cycle 2 Microcomputer (control part) 3 Compressor 4 Condenser 5 Pressure reducer 6 Evaporator 9 Inverter circuit 10 Vibration sensor 11 Quiet mode input switch (Quiet mode setting means) 12 Inside temperature setting switch (Inside temperature setting means) ) 13 internal temperature sensor (internal temperature detection means) 14 timer (time measuring means) 15 nighttime detection sensor (nighttime detection means) 17 maximum output frequency determination circuit (output frequency control means) 18 internal temperature detection circuit (internal temperature detection) 19) Zone determination circuit (output frequency determination means) 20 Zone correction circuit (temperature difference correction means) 22 Output frequency correction circuit (output frequency correction means) 40 Door open / close detection sensor (open / close detection means)

Claims (4)

[Claims] 1. A silent mode setting means for setting a silent mode, comprising a refrigeration cycle in which a compressor, a condenser, a decompressor and an evaporator are communicated with each other, and an inverter circuit for driving and controlling the compressor according to an output frequency. And a output frequency control unit for controlling the output frequency to be lower than the commercial power supply frequency when the silent mode is set by the silent mode setting unit. 2. A night detecting means for detecting night, a time measuring means for counting time from when night is detected by the night detecting means, and an open / close detecting means for detecting opening / closing of a refrigerator door at night. When night time is detected by the night time detection means, and when it is detected by the time measurement means and the opening / closing detection means that the door is not opened / closed for a predetermined time, a silent mode switching control means is provided for controlling to switch to the silent mode. The refrigerator according to claim 1, wherein the refrigerator is provided. 3. An inside temperature detecting means for detecting the inside temperature, and an inside temperature setting means for setting the inside temperature to a desired temperature.
Output frequency determining means for determining the output frequency of the inverter circuit according to the difference between the detected temperature in the refrigerator and the set temperature is provided, and the silent mode is set by the silent mode setting means, or night detecting means 3. When the nighttime is detected by, the temperature difference correction means for correcting the hysteresis temperature difference corresponding to the output frequency determined by the output frequency determination means is provided so as to be widened. refrigerator. 4. An output frequency of the inverter circuit is slightly adjusted so that the compressor does not resonate with a vibration detecting means for detecting the vibration of the compressor and a frequency of the vibration of the compressor detected by the vibration detecting means. 4. The refrigerator according to claim 1, further comprising an output frequency correction unit that corrects the shift frequency.