JP4722075B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to improvement of user safety.

  As a conventional air conditioner, for example, a microcomputer (hereinafter also referred to as a microcomputer) switch 13 (on the upstream side of the air outlet member 7 (region located on the cross flow fan 4 side as viewed from the air outlet member 7)) The microcomputer side switch 13 as the first detecting means detects attachment / detachment of the air outlet member 7 and notifies the controller (not shown) of attachment / detachment of the air outlet member 7. Further, a power circuit side switch 14 (see FIG. 1) as a second detecting means is arranged on the wall surface facing the fitting portion 47 of the drain pan 8. The power circuit side switch 14 is a blower. The attachment / detachment of the outlet member 7 is detected, and the ON / OFF of the operation power supply of the indoor unit is switched based on the attachment / detachment state of the air outlet member 7 ”(for example, see Patent Document 1). .

JP2003-240259A (paragraph number 0030, FIGS. 1 and 2)

  An air conditioner having a filter for filtering indoor air dust may cause clogging of the filter due to long-time operation, causing increased power consumption, abnormal stoppage, generation of mold, or odor . For this reason, it is necessary to periodically remove the filter from the air conditioner and clean it. In recent years, in particular, not only specialists but also general users perform cleaning because of increasing energy-saving and health-consciousness. However, it is considered that a general user has a high possibility of opening the suction port while operating the air conditioner by mistake for cleaning the filter. In such a case, it is possible to easily touch a rotating object such as a fan installed in the air conditioner, which is very dangerous.

  Conventionally, a shield such as a wire mesh has been installed around a rotating object such as a fan as a method of preventing the rotating object such as a fan installed in the apparatus during operation of the air conditioner. It was. In addition, for example, a detection device such as a sensor or a switch is installed to detect the attachment / detachment of the air outlet member, and the detection device detects the attachment / detachment of the air outlet member to stop the operation of the fan (for example, Patent Document 1).

  However, in a conventional air conditioner, for example, when a shield such as a wire mesh is installed around a rotating object such as a fan, the product cost increases due to an increase in the number of parts, or a wire mesh installed around the fan. There was a problem that aerodynamic performance deteriorated, resulting in a decrease in air volume and noise. In addition, when a sensor or switch for detecting the opening / closing of the suction port is installed, the influence on the aerodynamic performance is small, but there is a problem that the product cost increases due to an increase in the number of parts.

  The present invention has been made to solve the above-described problems, and is capable of improving user safety without causing an increase in product cost due to an increase in the number of parts and deterioration in aerodynamic performance. To get a harmony machine.

An air conditioner according to the present invention includes a housing in which at least an air suction port and a blowout port are formed, a grill that covers the suction port so as to be openable and closable, and an inner side of the grill that is sucked from the grill. A filter that filters air dust, a heat exchanger disposed in the housing, and a fan that blows air sucked from the suction port through the filter through the heat exchanger and blown from the blowout port. In the air conditioner including a drive motor for driving the fan, a rotation speed detection unit for detecting the rotation speed of the drive motor, and a control unit for controlling the drive motor, the control unit includes: the ≦ N _th condition | said detected by the rotational speed detecting means rotational speed N _i with 0 ≦ difference between the target rotation speed N _t of the driving motor with respect to the set value N _th | N _i -N _t When satisfied, the drive motor is safe. If it is determined that it is in a constant state and the condition of 0 ≦ | N _i −N _t | ≦ N _th is not satisfied in the stable state, the command voltage applied to the drive motor is increased, and the command voltage is after increasing, the difference N _D = N ₀ -N _i between the rotational speed N _i detected by the driving motor and the rotational speed N ₀ of the stable state the rotational speed detecting means with respect to the set value N _th When N _D > N _th , it is determined that the suction port is open, and the drive motor is stopped.

  In this invention, even if the suction port is opened while the air conditioner is accidentally operated for cleaning the filter, is the suction port open based on the instantaneous rotational speed of the driving motor that drives the fan? Since the drive motor is stopped when it is determined that the suction port is in an open state, the safety of the user is improved without causing an increase in product cost due to an increase in the number of parts and aerodynamic performance. can do.

Embodiment.
1 and 2 are perspective views showing the appearance of an indoor unit of an air conditioner according to an embodiment of the present invention. FIG. 1 shows a state where the grill 4 is closed, and FIG. 2 shows a state where the grill 4 is opened. Show. The indoor unit of the air conditioner in the present embodiment is, for example, a ceiling-suspended indoor unit. A casing 1 of the indoor unit has a horizontally long, substantially rectangular parallelepiped shape, and a suction port 2 is provided on the lower surface of the casing 1. A grill 4 is provided in the suction port 2. One side surface of the grill 4 is rotatably connected to the housing 1 via a hinge 4a, and is configured to cover the suction port 2 so as to be freely opened and closed. A holding member 4b such as a catch is provided on the other side surface of the grill 4 and the portion of the housing 1 corresponding to this side surface. When the grill 4 closes the suction port 2, the holding member 4b is provided. Thus, the grill 4 is held in the housing 1. A filter 5 is provided on the inner side of the grill 4 (the surface facing the inside of the housing 1 when the suction port 2 is closed by the grill 4). A blowout port 3 is provided on the side surface of the housing 1. The outlet 3 is provided with a louver 3a. Inside the housing 1, a fan 6 and a DC brushless motor 7 that drives the fan 6 are provided. This DC brushless motor 7 corresponds to the drive motor of the present invention. Further, inside the housing 1, a control unit 8 is provided for performing a drive command to the DC brushless motor 7, controlling the number of rotations, and the like.

  Next, the air flow in the indoor unit will be described. When the DC brushless motor 7 is driven by a command from the control unit 8, the fan 6 rotates and indoor air is sucked from the suction port 2. The sucked air is filtered out air dust and the like in the process of passing through the filter 5 and blown toward a heat exchanger (not shown) provided in the housing 1. The air adjusted to a predetermined temperature in the process of passing through the heat exchanger is blown out into the room from the blowout port 3. The direction of the air blown into the room from the blowout port 3 is adjusted by the louver 3a.

  Dust and the like accumulate on the filter 5 due to the long-time operation of the indoor unit (drive of the DC brushless motor 7). When dust or the like accumulates on the filter 5, the filter 5 is clogged, resulting in an increase in power consumption or an abnormal stop of the indoor unit. Further, dust or the like that accumulates on the filter 5 may cause mold or a strange odor. Therefore, the user needs to periodically remove the filter 5 from the grill 4 and clean it.

  The filter 5 is provided inside the grill 4. Therefore, in order to remove the filter 5 from the grill 4, it is necessary to remove the holding member 4 b that holds the grill 4 and to open the suction port 2. However, the state in which the suction port 2 is open is a dangerous state because the user may touch a rotating object such as the fan 6 provided in the housing 1.

FIG. 3 is a control flowchart of the DC brushless motor 7 in the present embodiment. In step S1, the control unit 8 that has received a command for operating the indoor unit from the user by a remote controller or the like (not shown), the driving voltage V _m corresponding to the applied voltage of the present invention is applied to the DC brushless motor 7 in step S2. The brushless motor 7 is driven by applying the command voltage _Vsp, and the operation of the indoor unit is started. This command voltage V _sp is a voltage value corresponding to the rotational speed of the DC brushless motor 7. Storage means of the control unit 8 (not shown), the target rotational speed of the fan 6 as the air volume required by the user N _t [rpm] (i.e. the target rotation speed N _t of the DC brushless motor 7 [rpm]) and the command voltage The relationship with V _sp is stored in advance. Control unit 8, as the fan 6 becomes the target rotational speed becomes air volume required by the user N _t [rpm] (i.e. the target rotation speed N _t [rpm] of the brushless DC motor 7), a DC brushless command voltage V _sp Applied to the motor 7. In step S <b> 3, the control unit 8 detects the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7. The direct current brushless motor 7 has a built-in rotational speed detecting element for detecting the position of the rotor corresponding to the rotational speed detecting means of the present invention, and the controller 8 controls the instantaneous rotational speed _Ni [rpm] by this rotational speed detecting element. Can be detected.

In step S4, it is determined whether or not the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 is near the target rotational speed N _t [rpm]. In the present embodiment, whether or not the difference between the instantaneous rotational speed N _i [rpm] and the target rotational speed N _t [rpm] of the DC brushless motor 7 is equal to or smaller than a set value N _th [rpm], that is, 0 ≦ It is determined whether or not | N _i −N _t | ≦ N _th (5 [rpm] ≦ N _th ≦ 50 [rpm]).

In step S4, the instantaneous rotational speed N _i of the DC brushless motor 7 is 0 ≦ | N _i -N _t | is not satisfied ≦ N _th condition, the process proceeds to step S5. In step S5, the control unit 8 controls the command voltage V _sp. Specifically, the instantaneous rotational speed N ₁ of the DC brushless motor 7 when a certain command voltage V _sp1 is applied by the control unit 8 does not satisfy the condition of 0 ≦ | N ₁ −N _t | ≦ N _th In this case, the control unit 8 calculates the change width ΔV _sp1 of the command voltage so that the instantaneous rotation speed N ₁ approaches the target rotation speed N _t [rpm], and sends the command voltage V _sp2 = V _sp1 + ΔV _sp1 to the DC brushless motor 7. Apply.

From step S3 repeating the steps of the step S5 in the command voltage control cycle .DELTA.TV _sp seconds interval, the DC instantaneous rotational speed N _i is 0 ≦ a brushless motor 7 | N _i -N _t | if conditions are met ≦ N _th, step Proceeding to S6, it is determined that the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 is in a stable state. After that, in step S7, the control unit 8 detects the instantaneous rotation speed N _i [rpm] of the DC brushless motor 7, and in step S8, the instantaneous rotation speed N _i [rpm] of the DC brushless motor 7 is again set to the target rotation speed N _t [ rpm] is determined. When the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 satisfies the condition of 0 ≦ | N _i −N _t | ≦ N _th , the control unit 8 repeats the steps from Step S6 to Step S8, and the DC brushless motor 7 Is monitored that the instantaneous rotational speed N _i is in a stable state. The controller 8 includes a DC brushless motor 7 Stores instantaneously storing means the rotational speed N _i as N ₀ [rpm] at the time when a stable state.

DC brushless motor 7 in this embodiment, the filter 5 the pressure loss increases by clogging or the like, the pressure in the indoor unit is reduced, the instantaneous rotational speed N _i load applied is reduced to the DC brushless motor 7 is high Become. Also, like when you open the inlet 2, there is no pressure loss that occurs by the filter 5, the pressure in the indoor unit is increased, the instantaneous rotational speed N _i load applied is increased to the DC brushless motor 7 is low. The applied voltage to the DC brushless motor 7 at this time does not change.

If the suction port 2 is opened for cleaning the filter 5 or the like when the DC brushless motor 7 is at a rotational speed N ₀ [rpm] in a stable state (repetition of steps S6 to S8), the DC brushless motor 7 instantaneously rotational speed N _i decreases. At this time, the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 does not satisfy the condition of 0 ≦ | N _i −N _t | ≦ N _th in step S8. In this case, the control unit 8 in step S9 controls the command voltage V _sp. Thereafter, in step 10, the control unit 8 detects the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7. In step S11, it is determined whether or not the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 is near the rotational speed N ₀ [rpm] in the stable state. That is, the difference N _D = N ₀ −N _i between the rotational speed N ₀ [rpm] in the stable state and the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 is 0 ≦ | N _D | ≦ N _th. It is determined whether or not.

A limit is provided for the change width ΔV _sp1 of the command voltage that can be applied at one time. Since edge width of the instantaneous rotational speed N _i of the DC brushless motor 7 when the inlet 2 is opened [rpm] is large, the control of a single command voltage V _sp, instantaneous rotational speed N _i of the DC brushless motor 7 [ rpm] has not returned to the range of 0 ≦ | N _D | ≦ N _th . That is, N _D > N _th . At this time, the control unit 8 proceeds to step S12 and determines that the suction port 2 is open. If the instantaneous rotational speed N _i [rpm] temporarily does not satisfy the condition of 0 ≦ | N _i −N _t | ≦ N _th in step S8 due to the influence of noise or the like, the command voltage V _{sp in} step S9 is controlled. In step S11, the range is returned to the range of 0 ≦ | N _D | ≦ N _th . At this time, it returns to step S6 again and monitoring (repetition of the process of step S6 to step S8) is continued.

Here, in determining the open state of the suction port 2 in the present embodiment, the stable rotational speed N ₀ [rpm] is used because the stable rotational speed N ₀ [rpm] is the target rotational speed N _t [ rpm] and may converge with a certain deviation width, so that the open state of the suction port 2 can be determined more accurately. Theoretically, the rotational speed N ₀ [rpm] in the stable state and the target rotational speed N _t [rpm] are the same value, so the open state of the suction port 2 is determined using the target rotational speed N _t [rpm]. May be.

The set value N _th [rpm] is changed in a range of 5 [rpm] ≦ N _th ≦ 50 [rpm] depending on the operation state of the indoor unit (for example, the amount of air blown by the fan 6, cooling operation, or heating operation). To do. For example, when the air volume blown by the fan 6 is small, the instantaneous rotational speed N _i [rpm] and the target rotational speed N _t [rpm] of the DC brushless motor 7 are small, that is, the value of | N _i −N _t | is small. Therefore, in order to determine the open state of the suction port 2, it is necessary to reduce the value of N _th [rpm]. Further, for example, since air path resistance increases due to dew adhering to the heat exchanger during the cooling operation, in order to obtain a desired air volume, the instantaneous rotational speed N _i [rpm] of the DC brushless motor 7 is compared with that during the heating operation. In addition, it is necessary to increase the target rotational speed N _t [rpm]. Therefore, in order to determine the open state of the suction port 2, it is necessary to increase the value of N _th [rpm].
In this embodiment, the open state of the suction port 2 is determined using the instantaneous rotational speed N _i [rpm] once the command voltage V _sp is controlled. This is the determination of the open state of the suction port 2. Therefore, the open state of the suction port 2 may be determined using the instantaneous rotational speed N _i [rpm] immediately after detection.

  The control part 8 which judged that the suction inlet 2 is an open state in step S12 progresses to step S13, and stops the DC brushless motor 7. FIG. Thereafter, in step S14, the display means (not shown) informs the user that the suction port 2 is abnormally stopped due to the open state. The display means may be provided in the indoor unit, or may be provided in a place other than the indoor unit such as a remote controller. The DC brushless motor 7 does not resume driving unless a reset operation (for example, pressing a reset button provided in the indoor unit) is performed, that is, the indoor unit does not resume operation. Even if it continues, the fan 6 starts to rotate suddenly and there is no danger.

In the air conditioner configured as described above, even if the suction port 2 is opened while the indoor unit is erroneously operated for cleaning the filter 5, the instantaneous rotational speed N of the DC brushless motor 7 that drives the fan 6. _Since it is determined from _i [rpm] that the suction port 2 is in an open state and the DC brushless motor 7 is stopped, an accident in which the user touches a rotating object such as the fan 6 provided in the housing 1 is prevented. be able to. Therefore, the safety of the user can be improved without causing an increase in product cost due to an increase in the number of parts and a deterioration in aerodynamic performance.

  Since the display means informs the user that the suction port 2 is abnormally stopped due to the open state, the user can know the reason why the operation of the indoor unit has stopped. Therefore, the user can restart the operation of the indoor unit by resetting after cleaning the filter 5.

Due to the use of the rotational speed N ₀ of the stable state [rpm] In evaluating the open state of the intake port 2, the steady state rotational speed N ₀ [rpm] is the target revolution speed N _t [rpm] constant shift width Even if it converges, the open state of the suction port 2 can be determined more accurately.

The set value N _th [rpm] is changed in a range of 5 [rpm] ≦ N _th ≦ 50 [rpm] depending on the operation state of the indoor unit (for example, the amount of air blown by the fan 6, cooling operation, or heating operation). Therefore, the open state of the suction port 2 can be accurately determined regardless of the operating state of the indoor unit.

It is a perspective view which shows the external appearance in the state which the grille 4 of the indoor unit of the air conditioner in embodiment of this invention closed. It is a perspective view which shows the external appearance in the state where the grill 4 of the indoor unit of the air conditioner in embodiment of this invention opened. It is a control flowchart of the brushless motor 7 in embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Housing | casing, 2 suction inlet, 3 outlet, 3a louver, 4 grille, 4a hinge, 4b holding member, 5 filter, 6 fan, 7 DC brushless motor, 8 control part.

Claims (4)

A housing in which at least an air inlet and an outlet are formed;
A grill that covers the suction port in an openable and closable manner;
A filter that is installed inside the grill and filters the dust of air sucked from the grill;
A heat exchanger disposed in the housing;
A fan that passes air through the heat exchanger and blows air from the outlet through the filter;
A driving motor for driving the fan;
A rotational speed detection means for detecting the rotational speed of the drive motor;
A control unit for controlling the driving motor;
In an air conditioner equipped with
The controller is
The ≦ N _th condition | said detected by the rotational speed detecting means rotational speed N _i with 0 ≦ difference between the target rotation speed N _t of the driving motor with respect to the set value N _th | N _i -N _t When satisfied, the drive motor is determined to be stable,
If the condition of 0 ≦ | N _i −N _t | ≦ N _th is not satisfied in the stable state, the command voltage applied to the drive motor is increased,
After increasing the command voltage, the driving motor is the difference N _D = N ₀ -N _i between the rotational speed N _i detected by the rotational speed detecting means and the rotation speed N ₀ of the steady state set value N _When N _D > N _th with respect to _th , it is determined that the suction port is open ,
An air conditioner characterized in that the drive motor is stopped.   The air conditioner according to claim 1, further comprising display means for displaying that the drive motor has stopped because the suction port is open. 3. The air conditioner according to claim 1, wherein the set value N _th is 5 ≦ N _th ≦ 50 [rpm]. The controller is
The air conditioner according to claim 3, characterized in that the set value N _th changed based on the operating state of the air conditioner.

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