JPH0650596A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent reduction in the amount of air to be sucked even when a filter is clogged by a method wherein phase of voltage impressed on an indoor fan motor is controlled so that the number of rotation of the motor can reach a setpoint corresponding to a set value of wind amount, and the controlled phase value is shifted to a limit of an allowance of change, if it is out of the allowance of change. CONSTITUTION:A rotation number detecting circuit 31 detects a rotation number of an indoor fan motor 7M based on an output signal of a Hall element 24. Control parts 39 and 50 control phase of voltage impressed on the indoor fan motor 7M, while surveying detection results of a zero crossing detecting circuit 34 by using a phase control circuit 32 and a double-directioned thylinster 22, so that the rotation number detected by the rotation number detecting circuit 31 become the same as a setpoint. If controlled phase value is not in an allowance of change beta around a reference phase value alpha, control parts 30 and 50 shift the controlled phase value up to a limit (=alpha+{beta/2}). By this, air which is conditioned to have an optimum temperature can be obtained, and therefore, comfortability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which the voltage applied to an indoor fan motor is phase-controlled so that the rotational speed of the motor becomes a target rotational speed corresponding to a set air volume.

[0002]

2. Description of the Related Art An air conditioner sucks indoor air by operating an indoor fan, cools or warms the sucked air with a heat exchanger, and blows the indoor air. A filter is provided at the indoor air intake port, and the intake air is passed through the filter to remove dust and odors in the room.

Further, the rotation speed of the indoor fan motor is detected, and the voltage applied to the indoor fan motor is phase-controlled so that the detected rotation speed becomes a target rotation speed corresponding to the air volume set by the remote controller. This is called rotation speed feedback phase control.

[0004]

[Problems to be Solved by the Invention] As the driving progresses,
The amount of dust adhering to the filter increases, and eventually the filter becomes clogged.

When the filter is clogged, the rotation speed of the indoor fan motor changes in an increasing direction. At this time, the electric power supplied to the indoor fan motor is reduced by the operation of the rotational speed feedback phase control, whereby the rotational speed of the indoor fan motor is finally reduced to the target rotational speed, adjusted and stabilized.

However, in this case, a sufficient amount of intake air cannot be obtained, which adversely affects the operation of the refrigeration cycle equipment, and air conditioning air having an optimum temperature cannot be obtained, which deteriorates comfort. This invention takes the above circumstances into consideration,

According to the air conditioner of the first aspect, even if the filter is clogged, it is possible to suppress a decrease in the amount of intake air, thereby eliminating adverse effects on the refrigeration cycle equipment and obtaining air-conditioning air at an optimum temperature. The purpose is to ensure comfort.

In the air conditioner of the second aspect, even if the filter is clogged, it is possible to suppress the decrease of the intake air volume, thereby eliminating the adverse effect on the refrigeration cycle equipment and obtaining the air conditioning air of the optimum temperature. The purpose is to be able to ensure comfort and to reliably remove the clogging of the filter.

[0009]

An air conditioner according to a first aspect of the present invention includes means for detecting the rotation speed of a motor of an indoor fan, and the indoor fan so that the detected rotation speed is a target rotation speed corresponding to a set air volume. A means for controlling the phase of the voltage applied to the motor, a means for judging whether or not this phase control value is within an allowable change range centered on the reference phase value for obtaining the target rotation speed, and this judgment is acceptable. Means for continuing the phase control based on the detected rotation speed when the change width is present and means for shifting the phase control value to the limit value of the allowable change width when the determination is not within the allowable change width.

An air conditioner according to a second aspect of the present invention includes means for detecting the rotation speed of the motor of the indoor fan, and a voltage applied to the motor of the indoor fan so that the detected rotation speed becomes a target rotation speed corresponding to the set air volume. A means for controlling the phase, a means for judging whether or not the phase control value is within the allowable change range centered on the reference phase value for obtaining the target rotation speed, and when this judgment is within the allowable change range. A means for continuing the phase control based on the detected rotation speed, a means for shifting the phase control value to the limit value of the allowable change width when the determination is within the allowable change width, and a filter abnormality when the shift continues for a predetermined time. And a means for notifying that fact and a means for changing the predetermined time according to the phase control value at the time of the determination.

[0011]

In the air conditioner according to the present invention, the rotation speed of the motor of the indoor fan is detected, and the phase of the voltage applied to the motor of the indoor fan is set so that the detected rotation speed becomes the target rotation speed corresponding to the set air volume. Control. At this time, it is determined whether or not the phase control value is within the allowable change width around the reference phase value for obtaining the target rotation speed, and if it is within the allowable change width, the phase control based on the detected rotation speed is continued. . When the phase control value is out of the allowable change range, the phase control value is shifted to the allowable change range limit value.

In the air conditioner of the second aspect, the rotation speed of the motor of the indoor fan is detected, and the phase of the voltage applied to the motor of the indoor fan is set so that the detected rotation speed becomes the target rotation speed corresponding to the set air volume. Control. At this time, it is determined whether or not the phase control value is within the allowable change width around the reference phase value for obtaining the target rotation speed, and if it is within the allowable change width, the phase control based on the detected rotation speed is continued. . However, when the phase control value is out of the allowable change range, the phase control value is shifted to the limit value of the allowable change range. Then, if this shift continues for a predetermined time, the filter is considered to be abnormal, and the fact is notified. Note that the predetermined time in this case is changed according to the phase control value at the time of the above determination.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, A is an outdoor unit and B is
Is an indoor unit. These two units A and B constitute the next refrigeration cycle.

An outdoor heat exchanger 3 is connected to the discharge port of the compressor 1 via a four-way valve 2. An indoor heat exchanger 5 is connected to the outdoor heat exchanger 3 via an expansion valve 4 which is a pressure reducer. The suction port of the compressor 1 is connected to the indoor heat exchanger 5 via the four-way valve 2.

That is, the four-way valve 2 is set in a neutral state, and the refrigerant discharged from the compressor 1 is caused to flow in the direction of the solid line arrow in the figure to use the outdoor heat exchanger 3 as a condenser and the indoor heat exchanger 5 as an evaporator. If it is made to function, the cooling operation can be executed. The four-way valve 2 is switched, and the refrigerant discharged from the compressor 1 is caused to flow in the direction of the broken line arrow in the figure to set the indoor heat exchanger 5 to the condenser and the outdoor heat exchanger 3.
The heating operation can be performed by making the function as an evaporator.
An outdoor fan 6 is provided near the outdoor heat exchanger 3. When the outdoor fan 6 is turned on, the outside air circulates through the outdoor heat exchanger 3.

An indoor fan 7 is provided near the indoor heat exchanger 5. When this indoor fan 7 is turned on, indoor air is drawn into the indoor unit B through a filter (not shown) and is blown out indoors through the indoor heat exchanger 5. The control circuit is shown in FIG.

The indoor unit B is connected to the AC power source 10,
The outdoor unit A is connected to the indoor unit B via the power supply line ACL and the serial signal line SL. Further, a remote control type operation device (hereinafter, abbreviated as a remote controller) R is connected to the indoor unit B.

First, in the indoor unit B, the power source 10
The power supply circuit 21 is connected to the power supply line ACL. The power supply circuit 21 outputs an operating voltage for various devices in the indoor unit B.

An indoor fan motor (single-phase induction motor) 7M is connected to the power supply line ACL via a relay contact 33a and a bidirectional thyristor 22 in series. Reference numeral 23 is an operating capacitor.

The hall element 24 is connected to the indoor fan motor 7M. The hall element 24 is used for the indoor fan motor 7
The rotation of M is magnetically detected, and a pulse signal having a cycle corresponding to the rotation speed is output. The photocoupler 25 is connected to the power supply line ACL. This photo coupler 25 has a power supply voltage E
The pulse signal corresponding to the positive / negative level of is output.

Further, the indoor unit B has a control section 30 composed of a microcomputer and its peripheral circuits. A rotation speed detection circuit 31, a phase control circuit 32, a relay 33, a zero cross detection circuit 34, a memory 35, an indoor temperature sensor 36, and timers 37 and 38 are connected to the control unit 30.

The rotation speed detection circuit 31 detects the rotation speed of the indoor fan motor 7M based on the output signal of the hall element 24. The phase control circuit 32 controls on / off of the bidirectional thyristor 22 with a phase according to a command from the control unit 30. The zero-cross detection circuit 34 detects a zero-cross of the power supply voltage E based on the output signal of the photocoupler 25 and issues a pulse signal in synchronization with the detection timing. The memory 35 stores a target rotation speed Nt of the indoor fan motor 7M corresponding to the set air volume of the remote controller R, and a reference phase value α for obtaining the target rotation speed Nt.

On the other hand, in the outdoor unit A, the power supply circuit 41 is connected to the power supply line ACL. This power circuit 41
Outputs an operating voltage for various devices of the outdoor unit A.

The inverter circuit 42 is connected to the power supply line ACL. The inverter circuit 42 rectifies the power supply voltage E, converts the power supply voltage E into a voltage having a frequency according to a command from the control unit 30, and outputs the voltage. This output becomes drive power for the compressor motor 1M.

Further, the outdoor unit A has a control section 50 composed of a microcomputer and its peripheral circuits. The inverter circuit 42, the four-way valve 2, and the indoor fan motor 6M are connected to the control unit 50.

The remote controller R has a control unit 60 composed of a microcomputer and its peripheral circuits. A key switch group 61 and a display 62 are connected to the control unit 60. The key switch group 61 includes a large number of key switches 61a, 61b, ... 61n for setting operating conditions. The display 62 is a liquid crystal display for displaying operating conditions, a filter abnormality sign, and the like.

Here, the control units 30 and 50 control the entire air conditioner while transmitting and receiving data by a serial signal synchronized with the power supply voltage through the serial signal line SL, and have the following functional means. [1] Temperature Ta detected by the indoor temperature sensor 36 and the remote controller R
Means for obtaining the difference ΔT (= Ta−Ts) from the set temperature Ts as the air conditioning load. [2] A means for controlling the operating frequency of the compressor 1 (the output frequency of the inverter circuit 42) according to the obtained air conditioning load.

[3] Means for reading from the memory 35 the target rotational speed Nt of the indoor fan motor 7M corresponding to the set air volume of the remote controller R, and the reference phase value α for obtaining the target rotational speed Nt.

[4] The phase control circuit 32 and the bidirectional thyristor 22 are used and the detection result of the zero-cross detection circuit 34 is monitored so that the detected rotation speed N of the rotation speed detection circuit 31 becomes the target rotation speed Nt. Meanwhile, means for controlling the phase P of the applied voltage Vd to the indoor fan motor 7M. This phase control value P is a period during which the power to the indoor fan motor 7M is cut off. Note that this control is generally called rotational speed feedback phase control.

[5] Whether or not the phase control value P is within the allowable change width (= β) around the reference phase value α when the set time ts ₁ has elapsed since the start of operation or the change of the set air volume Means to judge. [6] A means for continuing the rotation speed feedback phase control based on the detected rotation speed N when the determination is within the allowable change range. [7] A means for shifting the phase control value P to a limit value (= α + {β / 2}) of the allowable change width when the above determination is within the allowable change width. [8] When this shift continues for a predetermined time ts _{2, it} is determined that the filter is abnormal and the remote control R indicates that.
Means to let you know. [9] Means for changing the predetermined time ts ₂ according to the phase control value P at the time of the above determination. Next, the operation of the above configuration will be described with reference to FIG.

During operation, the relay 33 is energized to contact the contact 33.
a is turned on, and the power supply voltage E is applied to the indoor fan motor 7M via the thyristor 22. At this time, the thyristor 22 is turned on and off, and the phase P of the voltage Vd applied to the indoor fan motor 7M is controlled as shown in FIG.

The phase control value P is an energization cutoff period from the zero cross point of the power supply voltage E, and the thyristor 2 only during that period.
2 is turned off, and the applied voltage Vd to the indoor fan motor 7M
Is set to zero. That is, the smaller the phase control value P, the larger the power supplied to the indoor fan motor 7M, and the higher the rotation speed of the motor 7M. On the contrary, the larger the phase control value P, the smaller the power supplied to the indoor fan motor 7M, and the rotation speed of the motor 7M is reduced.

Thus, when the indoor fan 7 is turned on, indoor air is sucked into the indoor unit B through a filter (not shown), and the sucked air is blown out into the room through the indoor heat exchanger 5.

By the way, when the operation is started or when the set air volume of the remote control P is changed (steps 101 and 102), the target rotational speed N of the indoor fan motor 7M corresponding to the set air volume of the remote control P is set.
t and the reference phase value α for obtaining the target rotational speed Nt are read from the memory 35 (step 103). Then, as shown in FIG. 4, the read reference phase value α is initialized as the phase control value P (step 104).

When the operation is started or the set air volume is changed, the time count t ₁ is executed by the timer 37 (step 105), and the time count t ₁ and the set time ts are set.
₁ is compared (step 106). The set time ts ₁ is stored in the memory 35 in advance.

While the time count t ₁ does not reach the set time ts ₁ (NO in step 106), the rotation speed N of the indoor fan motor 7M is detected (step 107), and the time count t ₂ described later is cleared. (Step 108
). Then, the detected rotation speed N is compared with the target rotation speed Nt (step 109), and the rotation speed feedback phase control is executed according to the comparison result.

In this rotation speed feedback phase control,
When the detected rotation speed N is smaller than the target rotation speed Nt (N <N
t), the phase control value P is reduced by a predetermined value ΔP (step 110). When the phase control value P decreases, the power supplied to the indoor fan motor 7M increases and the rotation speed N of the motor 7M increases. When the detected rotation speed N matches the target rotation speed Nt (N = Nt), the phase control value P at that time is held as it is (step 111).

When the detected rotation speed N is larger than the target rotation speed Nt (N> Nt), the phase control value P is increased by a predetermined value ΔP (step 112). When the phase control value P increases, the power supplied to the indoor fan motor 7M decreases,
The rotation speed N of the motor 7M is reduced.

By executing the rotation speed feedback phase control in this way, the rotation speed N of the indoor fan motor 7M is converged to the target rotation speed Ns. As a result, the air volume of the indoor fan 7 is maintained at the set air volume.

At this time, it is determined that the filter is normal (step 113), and the result of the determination is notified to the remote controller R (step 114). The remote control R does not display the filter abnormality sign because the filter is normal.

When the time count t ₁ reaches the set time ts ₁ (YES in step 106), the time count t ₁ is cleared (step 115), and the phase control value P at that time is centered on the reference phase value α. It is determined whether the allowable change width β is within or exceeds the limit value (= α + β / 2) (step 116). If the phase control value P is within the limit value as shown in FIG. 4 (N in step 116)
O), the rotation speed feedback phase control is continued. By the way, as the operation progresses, the amount of dust attached to the filter increases, and the filter eventually becomes clogged.

When the filter is clogged, the rotation speed N of the indoor fan motor 7M changes in an increasing direction.
At this time, due to the operation of the rotational speed feedback phase control, the phase control value P becomes the limit value (= α + β) as shown in FIG.
/ 2) is expanded to the place beyond. As a result, the electric power supplied to the indoor fan motor 7M is reduced, and eventually, the rotation speed N of the indoor fan motor 7M finally reaches the target rotation speed N.
It is reduced to s, adjusted and stabilized.

However, since a sufficient amount of intake air cannot be obtained as it is, the operation of the refrigeration cycle equipment is adversely affected, and the air-conditioning air at the optimum temperature cannot be obtained, and the comfort is deteriorated.

Therefore, the phase control value P is limited to the limit value (= α + β).
/ 2) (YES in step 116), the phase control value P is forcibly shifted to the limit value (= α + β / 2) as shown in FIG. 6 (step 117). When the phase control value P is shifted to the limit value (= α + β / 2), the electric power supplied to the indoor fan motor 7M increases, and the rotation speed N of the indoor fan motor 7M increases.

Therefore, even if the filter is clogged,
It is possible to suppress the decrease in intake air volume as much as possible,
The adverse effect on the refrigeration cycle equipment is eliminated, and the air-conditioning air at the optimum temperature is obtained to ensure comfort.

At the same time as the shift of the phase control value P, the timer 37
Then, the time count t ₂ is executed (step 118), and the time count t ₂ is compared with the predetermined time ts ₂ (step 119). The predetermined time ts ₂ is stored in the memory 35 in advance.

If the time count t ₂ does not reach the predetermined time ts ₂ (NO in step 119), it is judged that the filter is normal (step 113), and the result of the judgment is notified to the remote controller R (step 114). The remote control R does not display the filter abnormality sign because the filter is normal.

When the time count t ₂ reaches the predetermined time ts ₂ (YES in step 119), it is judged that the filter is abnormal (step 120), and the result of the judgment is notified to the remote controller R (step 114). The remote control R displays the filter abnormality sign on the display 62. The filter abnormality sign prompts the resident to remove the filter clogging, and the filter cleaning is performed by the resident.

As shown in FIG. 7, the limit value (= α +
from β / 2) in the phase advance direction, three phase regions X ₁ ,
X ₂ and X ₃ are sequentially set, and the length of the predetermined time ts ₂ is changed depending on where the phase control value P in the judgment step 116 is X ₁ , X ₂ and X ₃ . That is, X
If the value is ₁ , the shortest predetermined time ts ₂ is selected on the basis that the clogging amount is not too large. If it exists in X ₂ , it is determined that the clogging amount is large, and the predetermined time ts ₂ longer than X ₁ is selected. If it exists in X ₃ , the longest predetermined time ts ₂ is selected based on the judgment that the clogging amount is considerably large.

As described above, by changing the predetermined time ts ₂ according to the phase control value P in the judgment step 116, it is possible to perform the filter cleaning at the optimum timing according to the clogging amount of the filter, and it is reliable. It is possible to improve the sex.

On the other hand, the controller 30 not only detects the clogging based on the phase control value P, but also detects the clogging by integrating the operating time. The control of the clogging detection by this integration will be described below. Whether the operation is started or in progress is monitored (steps 201 and 202).
The operation accumulated time to held in is read (step 203).

The timer 38 starts the time count t ₃ (step 204), which is added to the read operation integrated time to to obtain a new operation integrated time to (step 205). Then, this new operation integrated time t
o is compared with the set time tso (step 206). When the operation is stopped (NO in steps 201 and 202),
The cumulative operation time to at that time is stored in the memory 35. This memory does not disappear even when the power is turned off.

During operation, the integrated operation time to is the set time tso
(YES in step 206), a sign lighting command is sent to the remote controller R based on the judgment that the filter has reached the cleaning required time (step 208). At the same time, the timer 38 starts the time count t ₄ (step 209).

The remote controller R displays the filter abnormality sign in response to the sign lighting command. The filter abnormality sign prompts the resident to need maintenance for the filter, and the filter cleaning is performed by the resident.

After cleaning the filter, it is necessary to cancel the display of the filter abnormality sign and initialize the accumulated operation time to, but the dedicated reset key for that purpose is the remote control R.
And its reset key operation is monitored (step
210).

Further, the reset function here has two modes M ₁ and M ₂ . In the mode M ₁ , the integration time initialization by the reset key operation is allowed only after the predetermined time ts ₄ has elapsed since the filter abnormality sign was displayed. In the mode M ₂ , the integrated time initialization by the reset operation is allowed regardless of the presence or absence of the filter abnormality sign display. These modes are selected by operating the inspection key provided on the remote controller R. For example, the mode M ₂ is selected and set when the inspection key is continuously pressed for a predetermined time, and the mode M ₁ is selected and set otherwise.

That is, when the resident regularly cleans the filter based on his own judgment, it is necessary to initialize the accumulated operation time to irrespective of the display each time.
Before operating the reset key, the check key is continuously pressed for a predetermined time to select the mode M ₂ . On the other hand, if the mode M ₁ is selected, the accumulated operation time to is not initialized unless the filter abnormality sign is displayed, and therefore, the unnecessary accumulated operation time to is initialized by an erroneous operation or a mischievous operation. Is prevented.

Therefore, when the reset key is operated (YES in step 210), the modes M ₁ and M ₂ are discriminated (step 211), and if the mode is M ₂ , the cumulative operation time to is immediately cleared (step). 212).

When the reset key is operated (step
209 YES), in mode M ₁ (step 211 YES),
The filter error sign has already been displayed (see step 213).
YES), and if the time count t ₄ has reached the predetermined time ts ₄ (YES in step 214), the accumulated operation time t
o is cleared. Then, the sign off command is sent to the remote controller R (step 216), and the display of the filter abnormality sign is canceled.

In the above embodiment, the phase control value P is made to correspond to the energization cutoff period to the indoor fan motor 7M.
The phase control value P is not limited to that, and may correspond to the energization period to the indoor fan motor 7M.

[0061]

As described above, according to the present invention,

The air conditioner according to claim 1 determines whether or not the phase control value with respect to the voltage applied to the indoor fan motor is within a permissible variation range centered on the reference phase value for obtaining the target rotation speed, If it is within the allowable change range, the phase control based on the detected rotation speed is continued, but if the phase control value is out of the allowable change range, the phase control value is shifted to the limit value of the allowable change range. Even when the filter is clogged, it is possible to suppress a decrease in the amount of intake air, thereby eliminating adverse effects on the refrigeration cycle equipment and obtaining air-conditioning air at an optimum temperature to ensure comfort.

In addition to the structure of claim 1, the air conditioner of claim 2 is configured to notify the filter abnormality when the shift of the phase control value continues for a predetermined time. Therefore, even if the filter is clogged, suction is performed. It is possible to suppress a decrease in air volume, which eliminates adverse effects on refrigeration cycle equipment, obtains air conditioning air at the optimum temperature to ensure comfort, and reliably removes filter clogging. To be done.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control circuit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a refrigeration cycle in the same embodiment.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

FIG. 4 is a signal waveform diagram showing a phase control value at the start of operation in the embodiment.

FIG. 5 is a signal waveform diagram showing a phase control value when the filter is abnormal in the embodiment.

FIG. 6 is a signal waveform diagram showing a shift state of a phase control value according to the present invention.

FIG. 7 is a signal waveform diagram showing a region of a phase control value when a filter is abnormal in the embodiment.

FIG. 8 is a flowchart for explaining clogging detection by integrating operating time in the embodiment.

[Explanation of symbols]

1 ... Compressor, 3 ... Outdoor heat exchanger, 5 ... Indoor heat exchanger, 7
... Indoor fan, 7M ... Indoor fan motor, 22 ... Bidirectional thyristor, 24 ... Hall element, 30, 50 ... Control unit, A ... Outdoor unit, B ... Indoor unit, R ... Remote control.

Claims (2)

[Claims] 1. An air conditioner that sucks indoor air through a filter by operating an indoor fan, blows the sucked air into a room through a heat exchanger, and means for detecting the rotation speed of a motor of the indoor fan. Means for controlling the phase of the voltage applied to the motor of the indoor fan so that the detected rotation speed becomes the target rotation speed corresponding to the set air volume, and this phase control value is used as a reference phase value for obtaining the target rotation speed. Means for determining whether or not it is within the allowable change width around the center, means for continuing the phase control based on the detected rotation speed when this determination is within the allowable change width, and the determination is for not within the allowable change width. An air conditioner comprising means for shifting the phase control value to the limit value of the allowable change width. 2. An air conditioner that sucks indoor air through a filter by operating an indoor fan, blows the sucked air into a room through a heat exchanger, and means for detecting the rotational speed of a motor of the indoor fan. Means for controlling the phase of the voltage applied to the motor of the indoor fan so that the detected rotation speed becomes the target rotation speed corresponding to the set air volume, and this phase control value is used as a reference phase value for obtaining the target rotation speed. Means for determining whether or not it is within the allowable change width around the center, means for continuing the phase control based on the detected rotation speed when this determination is within the allowable change width, and when the determination is within the allowable change width A means for shifting the phase control value to the limit value of the allowable change width, a means for notifying that the filter is abnormal when the shift continues for a predetermined time, and the predetermined time for the judgment. An air conditioner comprising means for changing the phase control value at that time.