JP2005201565A - Indoor unit of air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indoor unit of an air conditioner comprising a cross flow fan long in its axial direction as an air fan, and achieving silence operation by reducing the operation noise such as air blasting noise in accompany with air blasting. <P>SOLUTION: This indoor unit comprises an air channel T communicating a suction ports 11, 12 and a blowout port 13, and the cross flow fan 16 mounted in the air channel, in a unit main body 10, a microphone 30 detects the operation noise including the air blasting noise of the cross flow fan, a controller 50 inputs and operates a detection signal detected by the microphone and produces and outputs a control sound signal of approximately opposite phase to the detection signal, a speaker 20 receives the control sound signal from the controller, generates the control sound to counteract the operation noise including the air blasting noise of the cross flow fan, the plurality of microphones, controllers and speakers are mounted in a state of respectively constituting independent control systems K1-K4, and the microphones and the speakers are mounted at specific intervals along the axial direction of the cross flow fan. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an indoor unit of an air conditioner provided with an active noise control mechanism that reduces and controls operation noise such as blowing noise generated during operation.

Noise, vibration, voltage or current detection means, sound generation means such as speakers, and processing means for processing these signals are used to reduce and control operating noise such as blowing sound emitted from a crossflow fan that is a blowing fan. An indoor unit of an air conditioner equipped with an active noise control mechanism (also called ANC) is known.
FIG. 1 is a schematic explanatory diagram of a basic active noise control mechanism. A speaker 2 as sounding means and a microphone (hereinafter referred to as a microphone) 3 as noise detecting means are arranged in the vicinity of the cross flow fan 1. Further, an auxiliary microphone 4 serving as a reference signal detecting means for detecting a driving sound that is a reference for noise is arranged at a position separated from the cross flow fan 1. These speaker 2, microphone 3 and auxiliary microphone 4 are electrically connected to a controller 5 which is active noise control means.

  The microphone 3 detects operation noise such as blowing sound that is blade pitch sound accompanying the blowing action of the cross-flow fan 1 that is the target workpiece, and the signal is input to the controller 5. At the same time, a reference signal from the auxiliary microphone 4 having a correlation with the noise detected by the microphone 3 is also input to the controller 5. The controller 5 compares the detected signal detected by the microphone 3 with the reference signal from the auxiliary microphone 4 as a reference, generates a signal having a phase substantially opposite to the detected signal, and outputs the signal to the speaker 2.

  The sound generated from the speaker 2 is a control sound, and the microphone 3 detects again a synthesized sound of the control sound and operation noise such as a blowing sound of the cross flow fan 1 and sends a detection signal to the controller 5. The controller 5 again sends a control sound signal to the speaker 2 based on the reference signal from the auxiliary microphone 4. These series of operations are repeated so that the detection signal in the microphone 3 is always controlled to a minimum value. Eventually, the operation noise such as the blowing sound is canceled out by the control sound, so that the noise can be substantially reduced.

[Patent Document 1] includes a driving sound detection means, a reference driving sound setting means, and a correction sound generation means based on the above-described active noise control mechanism, and the driving sound (time fluctuation amount) is predetermined. Disclosed is a technique for emitting a correction sound such that a synthesized sound with a driving sound becomes a reference driving sound compared with a reference driving sound set by a reference driving sound setting means when the correction sound generating means is larger than the level Has been.
Japanese Patent No. 3371446

By the way, in claim 1 in the above-mentioned [Patent Document 1], one of the features is that the detected driving sound is compared with the set reference driving sound, and a correction signal based on the difference between the two driving sounds is generated. It is said.
However, the driving sound is a real-time signal, whereas the reference signal based on the reference driving sound is not a real-time signal. In order to output the difference signal from the speaker in real time, some kind of synchronization signal (reference signal) that matches the pace of the driving sound and the reference driving sound is required, but [Patent Document 1] has a description related thereto. In addition, sound control is considered impossible with the above-described configuration.

In [Patent Document 1], paragraph numbers (0012) to (0014) of the specification include a description of the configuration of the air conditioner shown in FIGS. 5 and 6 and a description of the block diagram of FIG. The signal output from one signal processing circuit is guided to two speakers attached to the left and right walls of the air outlet.
According to the experimental measurement by the inventors of the present applicant, noise generated in a fan that is long in the axial direction, such as a crossflow fan, is affected by a heat exchanger, an air purifier, an air purifying filter, etc. It has been found that it is easily affected by the reflection of the back plate surrounding the fan, and as a result, it is not uniform in the longitudinal direction of the fan. Therefore, noises of the same level are not generated at the left and right wall portions of the air outlet, so that it is impossible to reduce the operation noise with the above-described configuration.

  The present invention has been made paying attention to the above circumstances, and its object is to provide a cross flow fan that is long in the axial direction as a blower fan, and to reduce operation noise such as blown sound caused by blown air. It is intended to provide an indoor unit of an air conditioner that operates.

  In order to satisfy the above object, an indoor unit of an air conditioner according to the present invention includes an air flow path communicating with a suction port and a blow-out port in a unit body, and a cross-flow fan disposed in the air flow path, and a noise detection means Detects the operating noise including the blowing sound of the cross-flow fan, and the active noise control means inputs and calculates the detection signal detected by the noise detection means, and generates a control sound signal that is substantially in phase with the detection signal The sound generation means receives the control sound signal from the active noise control means, generates a control sound, and cancels the operation noise including the blowing sound of the cross-flow fan, and the noise detection means, the active noise control means, and the sound generation means A plurality of each are provided as independent control systems, and the noise detection means and the sound generation means are arranged at predetermined intervals along the axial direction of the crossflow fan.

  According to the present invention, it is possible to reliably reduce the operation noise such as the blowing sound caused by the blowing, and to obtain a silent operation.

Hereinafter, an indoor unit of an air conditioner including an active noise control mechanism according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a schematic sectional view of the indoor unit according to the first embodiment of the present invention, and FIG. 3 is a schematic front view of the indoor unit according to the embodiment.
First, a schematic configuration of the indoor unit will be described. The unit main body 10 includes a front suction port 11 on the front surface portion and an upper surface suction port 12 on the upper surface portion. A grill is fitted into each of the front suction port 11 and the upper suction port 12. A blowout port 13 is opened along the lower side of the front suction port 11, and a louver (wind direction guide plate) is provided in the blowout port 13.

  A heat exchanger 14 that is bent in multiple stages and formed in a substantially inverted U shape in a side view is disposed in the unit main body 10, and faces the front air inlet 11 and the upper air inlet 12. Drain pans 15 a and 15 b that receive drain water generated by the heat exchanger 14 are disposed below the front and rear ends of the heat exchanger 14. A cross flow fan 16 that is a blower fan connected to a drive motor is provided so as to be surrounded by the heat exchanger 14 and the drain pans 15a and 15b. The length in the axial direction of the cross flow fan 16 is substantially the same as the dimension in the width direction of the heat exchanger 14 and is disposed so as to face each other.

  A nose 60 for guiding the air flow accompanying the driving of the cross flow fan 16 is provided at a further lower portion of the drain pan 15a below the heat exchanger 14 on the front suction port 11 side. A back plate 18 connected to the outlet 13 is provided further below the upper surface inlet 12 side drain pan 15b. The back plate 18 forms an air flow path T that communicates the front and top suction ports 11, 12 and the blowout port 13. A pipe storage unit 19 is provided at a corner of the unit main body 10 to store auxiliary piping (not shown) that extends from the indoor unit to the outdoor unit.

The active noise control mechanism N mounted in the indoor unit of such an air conditioner includes a plurality of microphones 30 as noise detection means, a speaker 20 as sound generation means, and a controller 50 as active noise control means, respectively. The reference signal auxiliary microphone 40 is a signal detection means.
The microphone 30, the speaker 20, and the controller 50 are provided four each, and each constitutes an independent loop (system). Therefore, in this embodiment, the active noise control mechanism N is composed of the four control systems K1 to K4. Only one auxiliary microphone 40 for reference signals is provided, and is connected in parallel to all the four control systems K1 to K4 described above.

The microphones 30 in the respective control systems K1 to K4 are arranged at the same height position on the front surface of the heat exchanger 14, particularly as shown in FIG. 3, and have a predetermined interval in the width direction of the heat exchanger 14. Installed.
The auxiliary microphone 40 for the reference signal is arranged together with the auxiliary pipe in the pipe housing part 19 which is a part where it is difficult to receive disturbance (other noise), and obtains one noise signal or vibration signal.

  The speaker 20 is attached to a nose 60 provided under the front side drain pan 15a. These speakers 20 are also attached to each other at a predetermined interval across the width direction of the nose 60 (that is, the width direction of the heat exchanger 14). A diaphragm (radiating surface) constituting the speaker 20 is provided facing the cross flow fan 16 from the nose 60, and sound can be generated with respect to a gap between the nose 60 and the cross flow fan 16.

In the indoor unit of the air conditioner having the active noise control mechanism N configured as described above, the refrigeration cycle operation is started based on the operation start command, and the refrigerant is condensed or evaporated in the heat exchanger 14. Is called. At the same time, the cross flow fan 16 is rotationally driven, and the room air is sucked into the unit main body 10 from the front suction port 11 and the upper suction port 12.
The indoor air sucked into the unit main body 10 passes through the heat exchanger 14 to exchange heat, and this heat exchange air is guided to the nose 60 and the air flow path T through the cross-flow fan 16 and from the outlet 13. It is blown into the room. In this state, the indoor cooling operation or heating operation is performed.

  In the active noise control mechanism N, each of the four microphones 30 detects an operation noise such as a blowing sound of the cross flow fan 16 and sends a detection signal to a dedicated controller 50 constituting each control system K1 to K4. . The auxiliary microphone 40 provided alone detects a standard driving sound in the pipe housing part 19 which is not easily affected by disturbance (other noise), and sends a reference signal as one noise signal or vibration signal to all the controllers 50. Send all at once.

In each controller 50 in each control system K1 to K4, a detection signal detected by the microphone 30 is input and a reference signal from the auxiliary microphone 40 is input. And the controller 50 of each control system K1-K4 calculates a detection signal based on a reference signal, and produces | generates the control sound signal of a substantially reverse phase with a detection signal.
The controller 50 in each control system K1-K4 outputs a control sound signal to the speaker 20 of the same control system K1-K4. Each speaker 20 receives a control sound signal output from the corresponding controller 50 and generates a control sound. Therefore, the operation noise such as the blowing sound of the cross flow fan 16 is canceled with the control sound from the speaker 20 and is reduced as an inverted sound.

The microphone 30 and the auxiliary microphone 40 again send a detection signal to the controller 50, which generates a control sound signal and sends it to the speaker 20. The speaker 20 generates a control sound again to further reduce driving noise. These actions are repeated, and finally the driving noise is close to mute.
The cross flow fan 16 is long in the axial direction, and the amount of noise such as blowing sound generated in each part is slightly different, and is not uniform along the longitudinal direction. On the other hand, since the plurality of microphones 30 and the speakers 20 are arranged at predetermined intervals along the axial direction of the cross flow fan 16, the controller 50, the microphones 30, and the control systems K1 to K4, respectively. The noise between the ranges that the speaker 20 is responsible for is made substantially uniform. That is, the control function of the active noise control mechanism N can be effectively obtained, and the efficiency of noise reduction can be improved.

The speakers 20 constituting the sound generating means used here have slit shapes whose lateral dimensions are extremely long relative to the longitudinal dimensions. On the other hand, the sound source of the blade pitch sound generated by the blowing action of the cross flow fan 16 is distributed in the vicinity of the gap between the nose 60 and the cross flow fan 16 and along the longitudinal direction of the cross flow fan 16. Yes.
Therefore, by using a plurality of the slit-shaped speakers 20 described above at a predetermined interval rather than the generally used circular or elliptical speakers, it is possible to radiate control sound to the sound source without waste and to be stored compactly.

The generation (sound source) of the blade pitch sound accompanying the blowing action of the cross flow fan 16 is between the nose 60 and the cross flow fan 16 or in the vicinity of the space. Can not expect. Therefore, the position where the sound of the speaker 20 is radiated into the unit main body 10 is set in the vicinity of the space between the nose 60 and the cross flow fan 16.
The auxiliary microphone 40 detects one noise signal or vibration signal as a reference signal. That is, since the cross-sectional geometry of the cross flow fan 16 is the same in any part, the frequency configuration of the noise is the same in any part. Therefore, even if there are a plurality of control systems, only one auxiliary microphone 40 is required, and the cost can be reduced by the difference from the number of control systems.

FIG. 4 is a view for explaining the mounting structure of the speaker 20A as the sound generation means according to the second embodiment of the present invention.
The speaker 20A is embedded in the side surface of the nose 60 facing the crossflow fan 16, the diaphragm (radiation surface) a faces the gap space between the nose 60 and the crossflow fan 16, and the radiation of the speaker 20A. The surface a also serves as one surface of the nose 60. Therefore, it is possible to suppress an increase in secondary blowing sound generated when the wind guided to the nose 60 strikes the speaker 20 </ b> A, and the speaker 20 </ b> A is mounted in the nose 60, which saves space.

  Note that, based on the second embodiment, the radiation surface a of the speaker 20B may be covered with a windbreak film b as shown in FIG. The windbreak film b is made of, for example, a porous cloth, a thin film, or the like, and has a characteristic that the passage of sound is not hindered but the wind is difficult to pass through. Therefore, by covering the radiation surface a of the speaker 20B with the windbreak film b, it is possible to prevent the generation of secondary fluid noise due to the unevenness of the shape of the sound radiation surface and to prevent condensation of the sound generation part.

FIG. 6 is a view for explaining a mounting structure of a speaker 20C as sounding means according to the third embodiment of the present invention.
A speaker 20C is embedded in a side surface of the nose 60 facing the crossflow fan 16, the diaphragm (radiation surface) a faces a gap space between the nose 60 and the crossflow fan 16, and the radiation surface a is windproof. Covering with the film b is the same as described above.

Here, the small hole 61 is provided in the side surface of the nose 60 to which the speaker 20C is attached, and the side surface of the nose 60 provided with the small hole 61 also serves as the radiation surface of the speaker 20C. The total area of the small holes 61 is set smaller than the area of the speaker diaphragm a.
Therefore, the sound wave generated from the diaphragm a of the speaker 20 </ b> C passes through the small hole 61 and is radiated to the gap between the nose 60 and the cross flow fan 16. In this case, since the area of the small hole 61 is made smaller than the area of the speaker diaphragm a, it is possible to aim at the sound source position and efficiently obtain noise reduction.

  The area of the speaker diaphragm a is determined by the frequency of sound that can be radiated, and the area is small to radiate a high frequency, but the area is large when a low frequency is radiated. On the other hand, the size of the sound source of the blade pitch sound generated with the rotation of the cross flow fan 16 is extremely small in the transverse cross-sectional direction of the unit body 10, and a speaker having a size corresponding to this width may be used. However, since the loudspeaker is generally larger due to the frequency characteristics, the small sound 61 is used to match the sound emitted from the loudspeaker 20C to the size of the sound source.

FIG. 7 is a view for explaining a mounting structure of a speaker 20D as sounding means according to the fourth embodiment of the present invention.
The speaker 20 </ b> D is attached to, for example, the front surface side which is a surface of the nose 60 other than facing the gap between the nose 60 and the cross flow fan 16. Further, a small hole 61 covered with a windproof film b is provided on a side surface of the nose 60 that faces the gap between the nose 60 and the cross flow fan 16.
By configuring in this way, the mounting structure of the speaker 20D to the nose 60 is simplified, and the mounting workability can be improved without using a useless space. Further, the nose 60 itself also serves as a sound guide path for the speaker sound, so that the sound produced by the speaker 20D can be efficiently guided to the gap between the nose 60 and the cross flow fan 16.

FIG. 8 is a schematic cross-sectional view showing an indoor unit structure according to the fifth embodiment of the present invention. Since the components excluding the parts to be described later are the same as those described above with reference to FIG. 2, the same reference numerals are given to the same components and a new description is omitted.
A sound absorbing material 70 is attached to a part of the inner surface side of the back plate 18 surrounding the cross flow fan 16. The sound source of the blade pitch sound generated by the airflow action of the crossflow fan 16 is present in the vicinity of the gap between the nose 60 and the crossflow fan 16, but the sound reflectivity of the back plate 18 surrounding the crossflow fan 16 is present. Is large, the sound from the sound source is repeatedly reflected by the air flow path T, and a large number of spurious sound sources are generated at a number of sites.

In order to effectively operate the active noise control mechanism N in this state, it is necessary to control each sound source, and the number thereof is enormous and cannot be controlled substantially. In order to avoid such a phenomenon, it is necessary to prevent unnecessary reflection of sound by absorbing a part of the back plate 18.
Therefore, unnecessary reflection of sound is prevented by attaching the sound absorbing material 70 to a part of the back plate 18 surrounding the cross flow fan 16 as described above. Such a sound absorption process is not limited to attaching the sound absorbing material 70, and naturally, the material of the back plate 18 constituting the air flow path T itself also has a sound absorbing property.
In addition, it goes without saying that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention includes all of them.

FIG. 3 is a diagram for explaining the operation of a basic active noise control mechanism in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The schematic sectional drawing of the air conditioner indoor unit based on 1st Embodiment in this invention, and the block diagram of an active noise control mechanism. The front view of the outline of the air conditioner indoor unit based on the said 1st Embodiment, and the block diagram of an active noise control mechanism. The figure explaining the attachment structure of the speaker based on 2nd Embodiment in this invention. The figure explaining the attachment structure of the speaker in the modification of the said 2nd Embodiment. The figure explaining the attachment structure of the speaker based on 3rd Embodiment in this invention. The figure explaining the attachment structure of the speaker based on 4th Embodiment in this invention. The schematic sectional drawing of the air conditioner indoor unit which shows the 5th Embodiment in this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Unit main body, 11 ... Front suction port, 12 ... Upper surface suction port, 13 ... Outlet, 16 ... Cross flow fan, 30 ... Microphone (noise detection means), 50 ... Controller (active noise control means), 20 ... Speaker ( Pronunciation means), 60 ... nose.

Claims (2)

In an indoor unit of an air conditioner including an air flow path that communicates a suction port and a blow-out port in a unit body, and a cross-flow fan disposed in the air flow path,
Noise detecting means for detecting operating noise including the blowing sound of the cross flow fan;
Active noise control means for inputting and calculating a detection signal detected by the noise detection means, and generating and outputting a control sound signal having an approximately opposite phase to the detection signal;
A sound generating means for receiving a control sound signal from the active noise control means to generate a control sound and canceling the operation noise including the blowing sound of the cross-flow fan;
The noise detection means, the active noise control means and the sound generation means are each provided in plural, and each is combined as an independent control system,
The indoor unit of an air conditioner, wherein the noise detection means and the sound generation means are arranged at predetermined intervals along the axial direction of the cross-flow fan.   2. Each of the sound generating means is arranged to generate a control sound with respect to a gap between the cross current fan and a nose formed in the vicinity of the cross current fan. Indoor unit of air conditioner.

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