JP2001317470A - Frequency control device and frequency control method of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frequency control device and a frequency control method of an air conditioner capable of restraining vibration of a compressor under all conditions. SOLUTION: A vibration sensor 7 is arranged for detecting the vibration of the compressor 6. When detecting output of this vibration sensor 7 exceeds a specific value, a control part 3 controls an operating frequency of the compressor 6 so that the detecting output of the vibration sensor 7 is set within the specific value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for controlling the operating frequency of a compressor in an air conditioner.

[0002]

2. Description of the Related Art In an air conditioner such as an inverter air conditioner, it is unavoidable that vibration occurs in an outdoor unit.
This vibration generates noise. Therefore, in order to suppress noise, it is required to suppress vibration as much as possible.
The source of vibration of the outdoor unit is mainly a compressor (compressor), and suppressing the vibration of the compressor leads to the solution of the noise problem. For this reason, various systems have been conventionally proposed.

For example, Japanese Patent Application Laid-Open No. Hei 10-306941 discloses that the minimum rotation speed of a compressor is varied in accordance with the input current of an outdoor unit, and that when the load on the compressor is light, the vibration increases even if the minimum rotation speed is reduced. A method for controlling an air conditioner that is prevented from becoming impossible is disclosed. In addition, Japanese Unexamined Patent Publication
Japanese Patent Application Laid-Open No. 2-158935 discloses an operating frequency of an air conditioner in which the maximum operating frequency of a compressor is controlled so as to gradually decrease in accordance with an increase in outdoor air temperature, and the fluctuation of the operating frequency is reduced to suppress vibration. A control device is disclosed.

[0004]

However, the vibration of the compressor is greatly affected not only by the operating conditions such as the air volume and the rotation frequency of the motor, but also by the environmental temperature, etc., and is generated only by certain specific factors. Not something. Therefore, in the above publication, although the vibration problem can be partially solved under specific conditions, vibration cannot be suppressed under all conditions.

Japanese Patent Application Laid-Open No. 11-159489 discloses an air conditioner in which vibrations are canceled out by controlling the phases of a plurality of compressors. Therefore, it cannot be applied to the case where the number of compressors is one, and there is still a restriction.

SUMMARY OF THE INVENTION The present invention solves the above-described problems, and provides a frequency control device and a frequency control method for an air conditioner capable of suppressing the vibration of a compressor under all conditions. That is the task.

[0007]

In order to solve the above-mentioned problems, a frequency control device according to the present invention is provided with a vibration sensor for detecting a vibration of a compressor, and when a detection output of the vibration sensor exceeds a specified value. Then, the operating frequency of the compressor is controlled so that the detected output is within a specified value.

The frequency control method according to the present invention further comprises a step of reading a detection output of the vibration sensor, a step of comparing the value of the read detection output with a predetermined value, and a step of making the detected output value correspond to the predetermined value. If not, operating the compressor at the current operating frequency; and, when the detected output value exceeds the specified value, controlling the operating frequency of the compressor so that the detected output is within the specified value. Is provided.

In this manner, the vibration of the compressor can be directly detected by the vibration sensor. By controlling the operating frequency of the compressor by comparing the detected value with a specified value, the compressor can be operated under any conditions. Vibration can be reduced.

As the vibration sensor according to the present invention, various sensors such as a piezoelectric acceleration sensor, a strain gauge acceleration sensor, and a capacitance acceleration sensor can be used. In addition, as for the place where the vibration sensor is attached, an arbitrary place such as an accumulator attached to the compressor, the compressor itself, or an outdoor unit can be selected.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 shows a block diagram of an air conditioner according to the present invention. The air conditioner is indoor unit 1
00, an outdoor unit 200, and a remote controller 300. In the indoor unit 100, 1 is a control unit,
It is composed of a microcomputer including a PU.
Reference numeral 2 denotes an indoor fan provided in the indoor unit 100, which operates based on a signal from the control unit 1.

In the outdoor unit 200, reference numeral 3 denotes a control unit, which comprises a microcomputer including a CPU. 4 is a storage unit including a ROM and a RAM,
5 is an outdoor fan and 6 is a compressor. The outdoor fan 5 and the compressor 6 operate based on a signal from the control unit 3. Reference numeral 7 denotes a vibration sensor for detecting the vibration of the compressor 6, the details of which will be described later. Reference numeral 8 denotes a temperature sensor for measuring the outdoor temperature, which is constituted by, for example, a thermistor.

In the air conditioner having the above configuration, the control unit 1 of the indoor unit 100 drives the indoor fan 2 in response to a signal from the remote controller 300, and the control unit 1 sends the signal to the control unit 3 of the outdoor unit 200. Send The control unit 3 receives this signal, determines the operating frequency of the compressor 6 based on the temperature set by the remote controller 300 and the temperature detected by the temperature sensor 8, and drives the compressor 6 by the inverter circuit. Further, the control unit 3 drives the outdoor fan 5 based on the signal.

FIG. 2 is a schematic diagram showing the periphery of the compressor 6. The compressor 6 has a built-in high-output motor 9 such as an induction motor.
In the upper part, a compressed refrigerant is passed through a heat exchanger (not shown).
A discharge pipe 10 for sending out to the outlet is drawn out. Reference numeral 11 denotes an accumulator for storing the refrigerant returned from the heat exchanger through the inlet pipe 12 and returning the refrigerant to the compressor 6 from the outlet pipe 13 again. Above the accumulator 11, the above-described vibration sensor 7 is attached. In addition, 14 is a base of the compressor 6.

FIG. 3 is a schematic diagram showing a piezoelectric acceleration sensor which is an example of the vibration sensor 7. Reference numerals 21 and 22 denote a pair of piezoelectric elements constituting a bimorph piezoelectric body, which are attached to the front and back of the diaphragm 23. Diaphragm 23
Is made of a conductive and elastic metal. 2
Reference numerals 4 and 25 denote a pair of output terminals, 26 denotes a ground terminal continuous with the diaphragm 23, and 27 and 28 denote fixed blocks made of an insulating material. The fixed blocks 27 and 28 are attached to the accumulator 11 by appropriate means. Reference numeral 29 denotes a mass body, which is attached to the tip of a cantilever composed of the piezoelectric elements 21 and 22 and the diaphragm 23. A piezoelectric acceleration sensor having the above configuration is disclosed in, for example,
-181201.

When the compressor 6 vibrates due to the rotation of the motor 9, the mass body 29 is displaced in the direction of the arrow, and the diaphragm 23 is bent by this displacement. Along with this, a mechanical force acts on the piezoelectric elements 21 and 22, and electric charges are generated in proportion to the mechanical force. As a result, a voltage corresponding to the amount of displacement of the vibration of the compressor 6 is extracted from the output terminals 24 and 25 as a detection output.

FIG. 4 is a diagram showing an example of the relationship between the operating frequency of the compressor 6 and the displacement of the vibration sensor 7 in the inverter air conditioner. As can be seen, the displacement of the vibration greatly varies depending on the operating frequency. Here, M represents a predetermined specified value. By operating the compressor 6 such that the displacement amount does not exceed the specified value M, noise due to vibration can be suppressed. Note that the relationship between the operating frequency and the displacement amount in FIG. 4 is stored in advance in the ROM of the storage unit 4 as a table.

FIG. 5 is a flowchart showing a frequency control method in the air conditioner described above, and shows a procedure executed by a microcomputer constituting the control unit 3. Hereinafter, a procedure for controlling the operating frequency of the compressor 6 will be described with reference to this flowchart.

When an operation start signal from the remote controller 300 is sent from the controller 1 to the controller 3 (step S1), the controller 3 controls the motor 9 of the compressor 6 by an inverter circuit.
To start the compressor 6 (step S
2). When the compressor 6 starts, vibration is generated in the compressor 6, and the vibration is transmitted to the accumulator 11 (FIG. 2) attached to the compressor 6. As a result, the accumulator 11 also vibrates, and the mass 29 (FIG. 3) of the vibration sensor 7 is displaced with the vibration, and a detection output is output from the vibration sensor 7 according to the above-described principle.

The controller 3 reads the amount of displacement of the vibration sensor 7 from the detection output (step S3), and compares the amount of displacement with a specified value M shown in FIG. 4 (step S4).
Note that the value of the specified value M is stored in the storage unit 4 in advance, and the control unit 3 reads the specified value M from the storage unit 4 and compares it with the output of the vibration sensor 7. In step S3, the detection output of the vibration sensor 7 may be read over a certain period of time, and the average value thereof may be used as the read value.

As a result of the comparison, if the displacement of the vibration sensor 7 does not exceed the specified value M (NO in step S5),
The compressor 6 is operated at the current operation frequency (step S9). At this time, noise due to vibration does not matter. Thereafter, it is determined whether there is an operation stop signal from the remote controller 300, and if there is no operation stop signal (step S7N).
O), returning to step S3, the displacement of the vibration sensor 7 is monitored, and if the displacement does not exceed the specified value M, the operation state is continued as it is (step S9).

On the other hand, if the amount of displacement of the vibration sensor 7 exceeds the specified value M (YES in step S5), the control unit 3 refers to the table of the storage unit 4 and controls the compressor so that the amount of displacement is within the specified value. 6 is controlled (step S6). For example, in FIG. 4, when the displacement amount of the vibration sensor 7 exceeds the specified value M as shown in A, the inverter circuit is controlled so that the operation frequency becomes 38 Hz (B) to 42 Hz (C). Thereafter, it is determined whether there is an operation stop signal from the remote controller 300. If there is no operation stop signal (NO in step S7), the process returns to step S3 to monitor the displacement amount of the vibration sensor 7, and the displacement amount of the vibration sensor 7 is regulated. Until the value becomes equal to or less than the value M, steps S3 to S6 are repeated to control the operation frequency. When the displacement of the vibration sensor 7 becomes equal to or less than the specified value M (step S5NO), the compressor 6 is operated at the operation frequency at that time (step S9). As a result, noise due to vibration is suppressed to a certain level or less.

When an operation stop signal from the remote controller 300 is sent from the control unit 1 to the control unit 3, the control unit 3 receives the signal and controls the inverter circuit to stop the motor 9 of the compressor 6 (step S1). S8) The operation ends.

As described above, in the above-described embodiment, the vibration itself of the compressor 6 is directly detected by the vibration sensor 7, so that the vibration is surely provided that the vibration exceeds a certain level without being affected by the environment. Can be suppressed.

FIG. 6 is a schematic diagram showing another embodiment of the vibration sensor. Here, the vibration sensor 71 is constituted by a strain gauge type acceleration sensor. Numeral 31 denotes a diaphragm made of an insulating material, on both sides of which are provided resistance elements 32 to 35 made of a metal resistance wire or a metal foil. These resistance elements 32-35 are connected to form a bridge circuit. In addition, instead of metal resistance wire and metal foil,
It is also possible to use a semiconductor piezoresistive element. Three
6 is a fixed block made of an insulating material, 37 is a diaphragm 31
It is a mass body attached to the tip of.

In the above-described strain gauge type acceleration sensor, the mass body 37 is displaced in the direction of the arrow by the vibration of the compressor 6, and the displacement causes the diaphragm 31 to bend. For this reason, the resistance elements 32 to 35 undergo distortion and their resistance values change. Therefore, the change in the resistance value can be taken out as a displacement amount.

FIG. 7 is a schematic diagram showing another embodiment of the vibration sensor. Here, the vibration sensor 72 is configured by a capacitance type acceleration sensor. Reference numeral 40 denotes a housing of the sensor; 41, a vibrating body supported by elastic bodies 42, 43 such as springs so as to be able to move up and down; 46
Is a fixed electrode provided in the device. The movable electrode 44 and the fixed electrode 45 face each other at a fixed interval.

In the above-described capacitance type acceleration sensor, the vibration member 41 is displaced in the direction of the arrow by the vibration of the compressor 6, and the distance between the movable electrode 44 and the fixed electrode 45 changes due to the displacement. Therefore, both electrodes 44,
The capacitance between 45 changes with the vibration, and the change in the capacitance can be taken out as the amount of displacement.

FIG. 8 is a schematic view showing another embodiment of a place where the vibration sensor 7 is mounted, and shows a modification of FIG. 8, the same parts as those in FIG. 2 are denoted by the same reference numerals. In this example, the vibration sensor 7 is directly attached to the compressor 6. The compressor 6 is mounted on the base 1
4, the accumulator 11 is only supported by the compressor 6 with the outlet pipe 13 and a fixed band (not shown).
The vibration of the accumulator 11 is larger than that of the compressor 6. Therefore, it is more effective to attach the vibration sensor 7 to the accumulator 11 as shown in FIG. 2, but the vibration sensor 7 may be attached to the compressor 6 as shown in FIG.

FIG. 9 is a schematic view showing another embodiment of a place where the vibration sensor 7 is mounted, in which the vibration sensor 7 is mounted inside the housing 201 of the outdoor unit 200.
5 denotes an outdoor fan, and 6 denotes a compressor. Also in this case, the vibration transmitted from the compressor 6 to the housing 201 is detected by the vibration sensor 7 so that the compressor 6
Operating frequency can be controlled.

The present invention can adopt various forms other than the above-described embodiment. For example, in the above embodiment, the control units 1 and 3 are provided in the indoor unit 100 and the outdoor unit 200, respectively. However, the control unit is provided only in the indoor unit 100 so that the compressor 6 is controlled from the indoor unit 100. Is also good. Alternatively, on the contrary, the control unit is provided only in the outdoor unit 200 and the outdoor unit 200
May be controlled. Further, the vibration sensor 7 is not limited to the one described above, and another type may be adopted.

[0032]

According to the present invention, since the vibration of the compressor is directly detected by the vibration sensor, the vibration can be reliably detected and noise can be reduced without being restricted by the environment and conditions.

[Brief description of the drawings]

FIG. 1 is a block diagram of an air conditioner according to the present invention.

FIG. 2 is a schematic diagram around a compressor.

FIG. 3 is a schematic diagram illustrating an example of a vibration sensor.

FIG. 4 is a diagram showing a relationship between an operation frequency and a displacement amount.

FIG. 5 is a flowchart illustrating a frequency control method for an air conditioner according to the present invention.

FIG. 6 is a schematic diagram showing another embodiment of the vibration sensor.

FIG. 7 is a schematic view showing another embodiment of the vibration sensor.

FIG. 8 is a schematic diagram around a compressor according to another embodiment.

FIG. 9 is a partially cutaway front view of an outdoor unit according to another embodiment.

[Explanation of symbols]

 Reference Signs List 3 control unit 4 storage unit 6 compressor 7 vibration sensor 9 motor 11 accumulator 100 indoor unit 200 outdoor unit M specified value

Claims (8)

[Claims] 1. A compressor provided in an outdoor unit, a vibration sensor for detecting a vibration of the compressor, and a control unit for controlling an operation frequency of the compressor, wherein the control unit detects an output of the vibration sensor. Is determined to exceed a specified value, and the operating frequency of the compressor is controlled so that the detected output is within the specified value. 2. The air conditioner frequency control device according to claim 1, wherein the vibration sensor comprises a piezoelectric acceleration sensor having a vibration plate and a piezoelectric element attached to the vibration plate. 3. The frequency control device for an air conditioner according to claim 1, wherein the vibration sensor comprises a strain gauge type acceleration sensor having a vibration plate and a resistance element attached to the vibration plate. 4. The frequency control device for an air conditioner according to claim 1, wherein the vibration sensor comprises a capacitance type acceleration sensor having a movable electrode attached to the vibrator and a fixed electrode facing the movable electrode. . 5. The frequency control device for an air conditioner according to claim 1, wherein the vibration sensor is attached to an accumulator attached to the compressor. 6. The frequency control device for an air conditioner according to claim 1, wherein the vibration sensor is attached to the compressor. 7. The frequency control device for an air conditioner according to claim 1, wherein the vibration sensor is attached to an outdoor unit. 8. A frequency control method for an air conditioner, comprising: a compressor provided in an outdoor unit; a vibration sensor for detecting vibration of the compressor; and a control unit for controlling an operation frequency of the compressor. Reading the detection output of the vibration sensor; comparing the value of the read detection output with a predetermined specified value; if the detected output value does not exceed a specified value, the compressor is operated at a current operating frequency. And controlling the operating frequency of the compressor so that the detected output is within a specified value when the detected output value exceeds a specified value. Machine frequency control method.