JPH10160228A - Air-conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly detect choking of a filter without using a special part, such as a sensor. SOLUTION: When the rotational speed of a fan motor 76 is set according to an air flow by a rotational speed setting part 130, a microcomputer 74 sets a step for a control signal based on the setting thereof. By the step for the control signal, PWM control of the fan motor is performed. Further, the microcomputer corrects the actual step through the operation of a step comparing correction part 132 based on the output of a generator 122 corresponding to the rotation of a fan motor and effects feedback control. In this case, the set step for the control signal is compared with the step for the actual control signal, and based on the comparison result, it is decided by a deciding part 134 whether the filter is clogged or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for controlling indoor air by a refrigeration cycle. More specifically, the present invention relates to an air conditioner for controlling the temperature of air sucked from a room through a filter and blowing the air into the room to perform air conditioning.

[0002]

2. Description of the Related Art An air conditioner (hereinafter referred to as an "air conditioner") for controlling indoor air by cooling, dehumidifying, and heating operations.
) Sucks indoor air into the indoor unit by a blowing fan such as a cross flow fan. The temperature of the air sucked into the indoor unit is adjusted by passing through the heat exchanger, and the air is blown from the indoor unit into the room.
Thereby, the interior of the room is set to a desired air-conditioning state.

In an air conditioner, for example, the capacity of a compressor is controlled, and at the same time, the amount of air blown from an indoor unit and the direction of air flow are controlled, so that the room is efficiently brought into a desired air-conditioning state.

For this reason, in an air conditioner, D
Using a C motor (for example, a DC brushless motor), the rotation speed of the DC motor (DC brushless motor) is
There is a type in which the control is performed to change it finely.

On the other hand, the indoor unit is provided with a filter for removing dust and dirt in the air, and the air sucked from the room passes through the filter to remove the dirt and dust and regulate the temperature. This prevents the air from being blown back into the room together with the air, and prevents them from adhering to the heat exchanger and becoming contaminated, and from adhering between the fins of the heat exchanger and causing clogging. ing.

When the filter is clogged with dust or dirt attached to the filter, the amount of air blown decreases. As a result, the air conditioning capacity of the air conditioner decreases, and air conditioning must be performed with an unnecessarily large capacity. To prevent this, the filter must be cleaned to prevent clogging.

[0007] For this reason, some air conditioners provide a display for accumulating the operation time and prompting the user to clean the filter every time the accumulated time reaches a predetermined time. However, in this case, since the timing for prompting the cleaning does not take into account the contamination of the filter, clogging or the like of the filter cannot be prevented accurately.

On the other hand, the amount of air passing through the filter is measured, the degree of contamination of the filter is determined from the amount of air, and the change in the current value when the blowing fan is driven to obtain a predetermined amount of air. It is conceivable to judge from.

However, since the amount of air passing through the filter varies depending on the blowing capacity such as the number of revolutions of the cross flow fan, it is difficult to accurately detect the contamination of the filter. In addition, it is necessary to provide a dedicated sensor for measuring the amount of air passing through the filter.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and can easily and accurately detect filter dirt without specially providing a sensor or the like for measuring an air volume. The purpose is to propose an air conditioner.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of controlling the temperature of air sucked from a room based on operating environment conditions and set operating conditions by a heat exchanger forming a refrigeration cycle. An air conditioner that performs indoor air conditioning by blowing out air, and a filter that filters air passing through the air conditioner, sucks air inside the room through the filter, and allows air to be blown into the room as temperature-controlled air. A blower fan provided, a fan motor for rotating and driving the blower fan, and a power of a step set in advance so that the blower fan has a blower amount based on the operating environment condition or the set operating condition. Power supply means for supplying air from the power supply means to the fan motor so that the blower fan has a preset air flow rate. A driving power correcting means for correcting the flop,
Determining a change in the airflow resistance of the filter by comparing the preset power step and the power step corrected by the power correction means.

According to the present invention, the rotation speed of the fan motor is set according to the air volume of the blower fan. Further, since the number of revolutions of the fan motor is determined by the supplied electric power, the step of the electric power for driving the fan motor is set in advance in accordance with the air volume of the blower fan, that is, the number of revolutions of the fan motor. Here, when the air volume is set based on the operating conditions and the like, a step of the power of the fan motor for obtaining the air volume is set, and the fan motor is driven by the power of the set step.

On the other hand, the power correction means corrects the step of the power supplied to the fan motor so that the rotation speed of the fan motor becomes the set rotation speed. Thus, the blower fan rotates so as to have the set air volume.

Generally, in a motor such as a fan motor, the number of rotations increases as the load decreases. When the detection result of the rotation speed detecting means is higher than the set rotation speed, it is possible to determine that the air resistance increases and the amount of sucked air decreases, and that the load on the motor decreases. The filter is provided on the upstream side in the blowing direction of the blower fan, and when the blower fan is rotated, room air passes through the filter and is sucked.

Here, if the filter is clogged,
Since the load on the fan motor is reduced, the rotation speed of the fan motor is likely to be high, and the power correction means controls the power step for driving the fan motor in order to suppress the rotation speed of the fan motor from increasing. Lower.

The determination means compares the set power step with the power step actually corrected by the power correction means and supplied to the fan motor. If the actual step is low, the filter is not clogged. It can be determined that it has occurred. Thus, clogging of the filter can be accurately detected without providing a special component such as a sensor for detecting the air flow.

According to the present invention, when the fan motor is a DC motor and the power supply means supplies a pulse having a predetermined duty ratio, the power supply means and the power correction means perform the duty ratio of the pulse. Is changed in accordance with a preset step.

According to this invention, a DC (direct current) motor is used as the fan motor, and the rotation speed is controlled by changing the duty ratio of the power for driving the DC motor. At this time, the step of the duty ratio is set in accordance with the rotation speed of the fan motor, and the step of the duty ratio is changed by feedback control to keep the rotation speed of the fan motor constant. The judging means can judge the clogging of the filter by comparing the steps of the duty ratio.

In the present invention, the invention is not limited to the DC motor,
The present invention can also be applied to a configuration in which the number of rotations is controlled by phase control of an AC motor.

Further, the present invention is characterized in that it comprises a display means for performing a display based on the result of the judgment by the judgment means.

According to the present invention, it is possible to determine whether or not the filter is clogged from the display on the display means. When the filter is clogged, the filter may be cleaned. . According to the present invention, the clogging of the filter can be properly determined, so that the filter can be cleaned at an appropriate timing based on the display based on the determination result, and efficient air conditioning operation and maintenance can be performed.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.

FIG. 1 shows an air conditioner (hereinafter referred to as "air conditioner 10") applied to the present embodiment. The air conditioner 10 includes an indoor unit 12 and an outdoor unit 1.
4 and is operated / stopped by operating a remote control switch (hereinafter, referred to as “remote controller 120”). When the operating condition such as the operating mode and the set temperature is set by the remote controller 120 and an operation signal is transmitted, the air conditioner 10 receives the operation signal in the indoor unit 12 and operates based on the operation signal. .

FIG. 2 shows an indoor unit 1 of the air conditioner 10.
2 shows an outline of a refrigeration cycle configured between the outdoor unit 2 and the outdoor unit 14. Between the indoor unit 12 and the outdoor unit 14, a thick refrigerant pipe 1 for circulating a refrigerant
6A and a thin refrigerant pipe 16B are provided in pairs,
One end of each is connected to a heat exchanger 18 provided in the indoor unit 12.

The other end of the refrigerant pipe 16A is connected to the outdoor unit 1
4 is connected to the valve 20A. This valve 20A
Is connected to the four-way valve 24 via the muffler 22A. Each of the four-way valves 24 has a compressor 26.
Accumulator 26 and muffler 22B connected to
Is connected. Further, the outdoor unit 14 is provided with a heat exchanger 30. One end of the heat exchanger 30 is connected to the four-way valve 24, and the other end is connected to the valve 20B via a cooling / heating capillary tube 32, a strainer 34, an electric expansion valve 36, and a modulator 38. The other end of the refrigerant pipe 16B is connected to the valve 20B, thereby forming a closed circulation path of the refrigerant forming a refrigeration cycle between the indoor unit 12 and the outdoor unit 14.

In the air conditioner 10, the operation mode is switched between a cooling mode (dry mode) and a heating mode by switching the four-way valve 24. In FIG. 2, arrows indicate the flows of the respective refrigerants in the cooling mode (cooling operation) and the heating mode (heating operation).

FIG. 3 shows a schematic cross section of the indoor unit 12. The interior of the indoor unit 12 is covered by a casing 42 that is locked above and below (up and down in the plane of FIG. 2) a mounting base 40 fixed to an indoor wall surface (not shown). In the casing 42, a cross flow fan 44 is disposed at a central portion as a blower fan. The heat exchanger 18 is arranged from the front side to the upper side of the cross flow fan 44, and is located between the heat exchanger 18 and a suction port 46 formed on the upper side from the front side of the casing 42. , A filter 48 are arranged. An outlet 50 is formed at a lower portion of the casing 42. That is, the heat exchanger 18 and the filter 48 are provided on the upstream side of the cross flow fan 44.

Thus, in the indoor unit 12, the indoor air is sucked from the suction port 46 by the rotation of the cross flow fan 44, and the sucked air is filtered by the filter 4.
8 and the heat exchanger 18. Heat exchanger 18
The air that has passed through reaches the cross flow fan 44, is sent from the cross flow fan 44 to the outlet 50, and is blown out from the outlet 50 toward the room.

In the indoor unit 12, the heat exchanger 18 is cooled or heated by a refrigeration cycle.
The air sucked in from the room is subjected to heat exchange by passing between fins (not shown) of the heat exchanger 18, and is cooled or heated to a predetermined temperature, so that the air is blown into the room when it is blown into the room. Air conditioning.

A left and right flap 52 and an upper and lower flap 54 are provided in the outlet 50.
The direction of the conditioned air blown out can be changed by the second and upper and lower flaps 54.

As shown in FIG. 4, the indoor unit 12
Is provided with a power supply board 56, a control board 58, and a power relay board 60. On a power supply board 56 to which electric power for operating the air conditioner 10 is supplied, a motor power supply 62, a control circuit power supply 64, a serial power supply 66, and a drive circuit 68 are provided. The control board 58 is provided with a serial circuit 70, a drive circuit 72, and a microcomputer 74.

The drive circuit 68 of the power supply board 56 is connected to a fan motor 76 for driving the cross flow fan 44. In the present embodiment, a DC brushless motor is used as fan motor 76 as an example.

Drive power is supplied to the fan motor 76 from a motor power supply 62 in accordance with a control signal from a microcomputer 74 provided on the control board 58. At this time, the microcomputer 74 sets the output voltage to the drive circuit 68 to 12
It is controlled so as to be changed in 256 steps in the range of V to 36V.

The drive circuit 72 of the control board 58 is connected to an upper and lower flap motor 78 for operating the power relay board 60 and the upper and lower flaps 54. The power relay board 60 is provided with a power relay 80, a temperature fuse, and the like. The power relay 80 is operated by a signal from the microcomputer 74 to open and close a contact 80A for supplying power to the outdoor unit 14. Air conditioner 1
In the case of 0, the electric power is supplied to the outdoor unit 14 when the contact 80A is closed, so that the outdoor unit 14 is operated.

The upper and lower flap motors 78 are controlled in accordance with a control signal from the microcomputer 74 to control the upper and lower flaps 5.
Operate 4. When the upper and lower flaps 54 are swung in the vertical direction, the outlet 50 of the indoor unit 12 is opened.
The direction in which air is blown out of the apparatus is changed in the vertical direction. The operation of the upper and lower flaps 54 can be fixed so that the blowing wind can be directed to an arbitrary position. However, in the automatic mode, the operation is changed at random.

As described above, in the indoor unit 12 of the air conditioner 10, by controlling the rotation of the cross flow fan 44 and the operation of the upper and lower flaps 54, the desired air volume and direction or the air flow is controlled to make the room comfortable. The air conditioned by the air volume and the wind direction can be blown into the room.

The serial circuit 70 is connected to the microcomputer 74 and the serial power supply 66 of the power supply circuit 56, and further to the outdoor unit 14. The microcomputer 74 performs serial communication with the outdoor unit 14 via the serial circuit 70, and controls the operation of the outdoor unit 14.

Further, the indoor unit 12 is provided with a display circuit 82 having a receiving circuit for receiving an operation signal from a remote controller 120 to be described later, a display LED for operation display, and the like. 74. As shown in FIG. 1, the display portion 82A of the display substrate 82 is exposed on the surface of the casing 42, and an operation signal from the remote controller 120 is received and input by the display portion 82A.

As shown in FIG. 4, the microcomputer 74 includes a room temperature sensor 84 for detecting the room temperature and the heat exchanger 1.
8, a heat exchange temperature sensor 86 for detecting the coil temperature is connected, and further, a service LED provided on the control board 58 and an operation changeover switch 88 are connected. Note that a temperature sensor is also provided in a remote controller 120 to be described later, and the room temperature is normally measured by the remote controller 120 and transmitted at a predetermined timing.

The operation switch 88 is connected to the indoor unit 1.
7 is provided in a cover 42A that covers the front surface of FIG.
), For switching between normal operation and test operation performed at the time of maintenance, etc., and the supply of operating power to the air conditioner 10 can be cut off by opening the contact of the power switch 88A. Normally, this operation changeover switch 88 is
Normal operation is set. The service LED is provided in line with the operation changeover switch, and is turned on at the time of maintenance to notify a service person of a self-diagnosis result.

The indoor unit 12 is connected to the outdoor unit 14 via terminals 90A, 90B, 90C of the terminal board 90.

On the other hand, as shown in FIG. 5, the outdoor unit 14 is provided with a terminal plate 92, and terminals 92A, 92B, and 92C of the terminal plate 92 are respectively connected to terminals 90A of the terminal plate 90 of the indoor unit 12. , 90B,
90C. Thereby, the outdoor unit 1
Operation power is supplied to the indoor unit 12 from the indoor unit 12, and serial communication with the indoor unit 12 is possible.

The outdoor unit 14 includes a rectifying board 9
4. A control board 96 is provided. The control board 96 is provided with noise filters 100A, 100B, 100C, a serial circuit 102, a switching power supply 104, and the like, together with the microcomputer 98.

The rectifying board 94 includes a noise filter 100
A rectifies the power supplied through the A
The data is smoothed via 00B and 100C and output to the switching power supply 104. The switching power supply 104 is connected to the inverter circuit 106 together with the microcomputer 98.
As a result, electric power having a frequency corresponding to the control signal output from the microcomputer 98 is output from the inverter circuit 106 to the compressor motor 108, and the compressor 26 is rotationally driven.

The microcomputer 98 is connected to the inverter circuit 1
The frequency of the power output from 06 is off or 14Hz
The control is performed so as to be in the range described above (the upper limit is determined by the upper limit of the operating current).
08, that is, the rotation speed of the compressor 26 is changed,
Capacity of compressor 26 (cooling / heating capacity of air conditioner 10)
Is controlled.

The control board 96 includes a four-way valve 2
4 and a fan motor 110 for driving a fan (not shown) for cooling the heat exchanger 30 and a fan motor condenser 110A. Also, the outdoor unit 14
Are provided with an outside air temperature sensor 112 for detecting the outside air temperature, a coil temperature sensor 114 for detecting the temperature of the refrigerant coil of the heat exchanger 30, and a compressor temperature sensor 116 for detecting the temperature of the compressor 26. 98.

The microcomputer 98 switches the four-way valve 24 in accordance with the operation mode, controls the control signal from the indoor unit 12, the outside air temperature sensor 112, and the coil temperature sensor 1.
On and off of the fan motor 110, the operating frequency of the compressor motor 108 (the capacity of the compressor 26) and the like are controlled based on the detection results of the compressor 14 and the compressor temperature sensor 116.

As shown in FIG. 6, the fan motor 76 for rotating the cross flow fan 44 to blow air is provided with a generator 122 used for feedback control of the fan motor 76 and the like.
Is provided.

On the other hand, the drive circuit 68 for controlling the fan motor 76 is provided with a PWM 124 and a drive unit 126 and an amplification unit 128. A control signal obtained by dividing the voltage in the range of 12 V to 36 V into 256 steps is input from the microcomputer 74 to the PWM 124.

The PWM 124 changes the duty ratio of the DC power input from the motor power supply 62 according to the voltage input from the microcomputer 74 and outputs the DC power to the drive unit 126. The driving unit 126 drives the fan motor 76 to rotate by the electric power having a predetermined duty ratio output from the PWM 124. As a result, the rotation speed of the fan motor 76 changes between 600 rpm and 1150 rpm according to the control signal output from the microcomputer 74.

A generator 122 provided in the fan motor 76 is connected to the amplifying unit 128 so that the voltage output from the generator 122 is amplified according to the rotation of the fan motor 76 and output to the microcomputer 74. It has become.

On the other hand, in the microcomputer 74, the number of revolutions of the fan motor 76 (the number of revolutions of the cross flow fan 44) corresponding to the amount of air blown from the air conditioner 10 is obtained, and control signal steps for each number of revolutions are set. It is remembered. For this reason, when the air volume or the number of rotations is set, a step corresponding to the set number of rotations is obtained, and the steps from 12 V to
A control signal corresponding to a step in the range of 36 V is output.

In the air conditioner 10, the number of revolutions (for example, each of the air flow rates H, M, and L, which is 1150 rpm, and 1 for each of the air flow rates (for example, three levels of H, M, and L) set by the remote controller 120)
000 rpm, 920 rpm) to rotate the cross flow fan 44. When the air volume is set to automatic, the air volume is controlled based on the set operating conditions, room temperature, and the like. At this time, the rotation speed of the fan motor 76 is changed from 1150 rpm (maximum air flow) to 600 rpm (minimum air flow). The microcomputer 74 controls the fan motor 76 so that the rotation speed changes in 256 steps. Is output.

That is, the microcomputer 74 has a function of a rotation number setting section 130 for setting the rotation number of the fan motor 76 and a step conversion section 136 for setting the step of the control signal according to the set rotation number. The step set by the step converter 136 is output via the step comparison / correction unit 132 and the D / A converter 138, so that a control signal of a voltage corresponding to the set step is output to the PWM 124. .

The output of the amplifying unit 128 of the driving circuit 68 is input to the microcomputer 74 via the A / D converter 140. The output of the A / D converter 140 is input to the microcomputer 74. 132.

The step comparison / correction section 132 corrects (steps up or down) the step of the control signal based on the input from the A / D converter 140, and changes the rotation speed of the fan motor 76 to the set rotation speed. I'm trying to reach. By performing the feedback control of the fan motor 76 in this manner, the rotation speed of the fan motor 76, that is, the rotation speed of the cross flow fan 44 is maintained at the set rotation speed.

The microcomputer 74 is provided with a determination unit 134. The step comparison / correction unit 132 compares the step set by the step conversion unit 136 with the step corrected by the step comparison / correction unit 132. And outputs it to the determination unit 134.

The judgment section 134 is provided with the step comparison correction section 13
2, the comparison result (for example, the difference in the number of steps or the ratio of the difference) exceeds a predetermined value, and the step conversion unit 13
When the actual step is lower than the step set in 6, it is determined that the filter 48 is clogged.

Normally, regardless of whether the voltage supplied to the fan motor 76 does not change, when the actual rotation speed of the fan motor 76 changes, it can be determined that the load on the fan motor 76 has changed. On the other hand, in the indoor unit 12,
When the load of the fan motor 76 changes, a filter 4 that filters dust and dust from the air sucked into the indoor unit 12.
Eight clogging is considered. In other words, if dust or dust adheres to the filter 48 and clogging occurs, the amount of air to be sucked in decreases, so that the load on the fan motor 76 decreases and the rotation speed increases. In order to suppress the increase in the rotation, the step of the actual control signal is lowered from the step initially set.

The microcomputer 74 compares the step of the set control signal with the step of the actual control signal, and when the actual step becomes lower than a predetermined ratio based on the comparison result, the filter 48 is checked. It is determined that clogging has occurred.

As shown in FIG. 4, the display section 82 is provided with a display LED 136 which is turned on when it is determined that the filter 48 is clogged. As shown in FIG. 7, the display LED 136 is attached to the display panel 82A, and the lighting of the display LED 136 can be confirmed from the indoor side without removing the inside of the casing 42 by opening the cover 42A, for example. The microcomputer 74
When the determination unit 134 determines that the filter 48 is clogged, the display LED 136 of the display circuit 82 is turned on to indicate that the filter 48 is clogged and that maintenance such as cleaning or replacement is required. Display is performed.

The operation of this embodiment will be described below.

In the air conditioner 10, operating conditions such as an operation mode, a set temperature, a wind direction, and an air volume are set by operating the remote controller 120, and operation signals corresponding to these operating conditions and operation of a not-shown start / stop button are transmitted to the remote controller 120. Starts operation according to the operation signal. As a result, the room in which the indoor unit 12 of the air conditioner 10 is provided is set to a desired air condition according to the operation of the remote controller 120.

The operation of the air conditioner 10 is stopped when the operation / stop button of the remote controller 120 is operated during the air-conditioning operation and an operation signal for instructing stop is input from the remote controller 120.

The microcomputer 74 of the air conditioner 10 sets the operating capacity of the compressor 26 and the air flow rate of the cross flow fan 44 based on the set operating conditions and environmental conditions such as room temperature. The air-conditioning operation is performed based on this.

The number of rotations of the cross flow fan 44 is determined according to the amount of air blown. When the number of rotations is set according to the amount of air blown by the number of rotations setting unit 130, the drive signal of the step corresponding to this number of rotations is driven. It is output to the circuit 68. Drive circuit 68
Then, the fan motor 76 is driven by PWM control in which a DC voltage supplied from the motor power supply 62 is converted into a pulse width corresponding to the control signal and output. by this,
Air whose temperature is adjusted by the set air volume is blown out from the outlet 50 of the indoor unit 12.

At the same time, the microcomputer 74 compares the step of the drive signal set based on the amount of air blow with the step of the drive signal actually output to the drive circuit 68 by the feedback control of the fan motor 76. It is determined whether the filter 48 is clogged.

The determination of clogging of the filter 48 is shown in FIG.
This will be described with reference to the flowchart shown in FIG. This flowchart shows an example of detection of clogging of the filter 48 based on the driving power of the fan motor 76.

This flowchart is executed when the operation of the air conditioner 10 is started. In the first step 200, the fan motor 76 is controlled so as to obtain the air volume set based on the set operating conditions, the room temperature, and the like. Set the number of revolutions. Subsequently, in step 202, step F of a control signal for setting the fan motor 76 to the set rotation speed is set. Thereby, in step 204,
The set step F is set as a step f of a control signal for controlling the fan motor 76, and a control signal of a voltage corresponding to the step set in the drive circuit 68 is output. The motor 76 is driven to rotate.

On the other hand, in step 206, the output of the generator 122 according to the rotation of the fan motor 76 is read, and it is determined whether or not the actual rotation speed of the fan motor 76 is lower than the set rotation speed or the set rotation speed. To determine if This determination can be made by various conventionally known methods, for example, by comparing the voltage of the set control signal with the voltage of the generator 122 input through the amplifier 128.

Here, when the rotation speed of the fan motor 76 is low and it is necessary to increase the rotation speed, step 21 is executed.
Going to 0, the control signal step f is increased by one step. When the rotation speed of the fan motor 76 is high, the process proceeds to step 212, and the control signal step f is reduced by one step to suppress the rotation speed of the fan motor 76.

In this way, by correcting the step of the control signal by feeding back the rotation of the fan motor 76, the rotation speed of the fan motor 76 reaches the set rotation speed and is maintained at the set rotation speed. Is done.

On the other hand, in step 214, step f of the actual control signal is compared with step F of the control signal which is initially set according to the air flow rate.

Here, if the initially set step is substantially the same as the actual step, or if the actual step is at least within a predetermined ratio α (for example, α = 0.8), a negative determination is made in step 214. Then, the process proceeds to step 216. In step 216, it is checked whether or not the setting of the air volume has been changed. If the setting has not been changed (negative determination), the process proceeds to step 204. When the air volume is changed (affirmative determination), the process proceeds to the first step 200 to set a new rotation speed to a rotation speed, and to set a step F of a control signal according to the set rotation speed. Do.

On the other hand, when the difference between the actual step f and the set step F is equal to or more than the predetermined ratio α (Yes in step 214), the process proceeds to step 218, where the value of the error counter e is set. Is incremented (e =
e + 1). Note that this error counter e is
It is reset in advance at the start of the operation at 0.

In the next step 220, it is determined whether or not the count value of the error counter e is "1", that is, whether or not the counting by the error counter e has been started. Affirmative decision)
Then, the process proceeds to step 222 to reset / start the timer for measuring the count time of the error counter e.

In step 224, it is confirmed whether or not the count value of the error counter e has exceeded a predetermined value E (for example, 100). In step 226, it is determined whether or not the timer has timed out (measured time of the timer in advance). Check whether the set time (for example, one minute) has been exceeded.
Here, the count value of the error counter e is equal to a predetermined value E.
If the timer times out (affirmative determination in step 226) before the time reaches (negative determination state in step 224), the error counter and the timer are reset.
The counting is stopped (step 228).

On the other hand, if the count of the error counter e exceeds the predetermined value E before the timer expires (YES at step 224), the routine proceeds to step 230. That is, when the number of times that the actual step f falls below the ratio α with respect to the step F set within the predetermined time exceeds the predetermined value E, the filter 48 is clogged and the indoor air flow is generated by the cross flow fan 44. It is determined that the actual step f of the fan motor 76 is low because the airflow resistance when sucking the air increases.

When it is determined that the load on the fan motor 76 is low, and the process proceeds to step 230, the flag H indicating the occurrence of clogging of the filter 48 is set (H = 1), and the display circuit 82 Display LED 13
6 is turned on (step 232).

As a result, the display LED 136 in the display panel 82A provided on the front surface of the indoor unit 12 is turned on to urge the maintenance of the filter 48. In addition, while the flag H is set, the display LED 136 continues to light, the maintenance of the filter 48 is completed, and the step F of the control signal of the fan motor 76 and the step f of the actual control signal substantially coincide with each other. Then, it is reset (H = 0). When the flag H is set, the actual step f is not compared with the set step F, and only the feedback control of the fan motor 76 based on the set step F according to the set air volume is performed. (Steps 200 to 212 and 216 are repeated).

As described above, in this embodiment, it is possible to easily detect the clogging of the filter 48 without providing a sensor for detecting the clogging of the filter 48, and to prompt the maintenance of the filter 48. it can. At this time, erroneous detection of clogging of the filter 48 can be prevented by counting the number of times and time when the rotation speed f exceeds the rotation speed F, and the clogging of the filter 48 can be accurately detected. . Note that the present embodiment is an example of the present invention, and the present invention can be applied to all air conditioners for indoor air conditioning.

For example, in the present embodiment, the filter 48
Is displayed by the display LED 136 provided on the display panel 82A of the indoor unit 12.
The remote controller 120 may display an image on an LCD panel. In this embodiment, an example in which a DC brushless motor is used as the fan motor 76 has been described. However, the present invention is not limited to this. Can be used to change the load of the motor when controlling the rotation speed of the motor. For example, the present invention can be applied to a configuration in which an AC motor is used as the fan motor 76 and the phase control of the AC motor is performed.

[0083]

As described above, according to the present invention, clogging of the filter is determined by the difference between the power set to supply a predetermined air flow due to the change in the load of the fan motor and the power actually supplied. Since the determination is made, clogging of the filter can be accurately detected without providing a special sensor or the like. By displaying this detection result, the maintenance of the filter can be appropriately promoted, so that an excellent effect of enabling efficient air-conditioning operation can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an air conditioner applied to the present embodiment.

FIG. 2 is a schematic diagram showing a refrigeration cycle of an air conditioner applied to the present embodiment.

FIG. 3 is a schematic sectional view showing an indoor unit.

FIG. 4 is a block diagram schematically showing a circuit configuration of the indoor unit.

FIG. 5 is a block diagram schematically showing a circuit configuration of the outdoor unit.

FIG. 6 is a functional block diagram schematically illustrating drive control of a fan motor.

FIG. 7 is a perspective view of a main part of an indoor unit showing an example of a display means.

FIG. 8 is a flowchart illustrating an example of detection of clogging of a filter according to the present embodiment.

[Explanation of symbols]

Reference Signs List 10 air conditioner (air conditioner) 12 indoor unit 14 outdoor unit 18 heat exchanger 26 compressor 44 cross flow fan (blowing fan) 48 filter 62 motor power supply 68 drive circuit 74 microcomputer (drive control means, judgment means) 76 fan motor 122 Generator 124 PWM 130 Speed setting unit 132 Step comparison and correction unit (power correction unit, power supply unit, determination unit) 134 Determination unit (determination unit) 136 Display LED (display unit)

Claims (3)

[Claims] 1. An air conditioner for controlling air in a room by controlling the temperature of an air sucked from a room based on an operating environment condition and a set operating condition by a heat exchanger forming a refrigeration cycle and blowing the air. A filter for filtering the passing air; a blower fan provided so as to suck indoor air through the filter and to blow the air into the room as temperature-controlled air; and a fan for driving the blower fan to rotate. A motor, power supply means for supplying electric power of a preset step so that the blower fan has a blower amount based on the operating environment condition or the set operating condition, and the blower fan is preset. Power correction means for correcting a step of power supplied from the power supply means to the fan motor so that the blown air amount is adjusted, Determining a change in the ventilation resistance of the filter by comparing the step of the applied power with the step of the power corrected by the drive power correction unit. 2. The fan motor is a DC motor,
The power supply unit and the power correction unit change the duty ratio of the pulse according to a preset step when the power supply unit supplies a pulse having a predetermined duty ratio. 2. The air conditioner according to 1. 3. The air conditioner according to claim 1, further comprising a display unit that performs display based on a result of the determination by the determination unit.