JP2007155264A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of preventing overheat of an electric heater in the case of a nonuniform closure of an air passage. <P>SOLUTION: The air passage from a suction grille 16 to a blowout port 17 is composed. An indoor fan 7, an indoor fan case 8, and the electric heater 1 are arranged in the air passage. A resetting type overheat protection device 9 is provided for preventing overheat of the electric heater 1. A sensing part 9a of the resetting type overheat protection device 9 is exposed on the inner side of the indoor fan case 8. The air heated by the electric heater 1 is stirred in the indoor fan case 8. Even when the electric heater 1 is partly abnormally heated due to nonuniform closure of the air passage, by the air temperature after stirring, the resetting type overheat protection device 9 detects the abnormal heating of the electric heater 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air conditioner equipped with an electric heater in an air flow path from a suction port to a blowout port.

  In general, an air conditioner equipped with an electric heater is equipped with an overheat protection device to prevent overheating of the electric heater due to heat not being taken away when the amount of air passing due to clogging is reduced. . The overheat protection device detects abnormal heating of the electric heater and controls the electric heater to be electrically cut off, ensuring the safety of the air conditioner so as not to cause ignition from abnormal heating. .

  FIG. 6 shows an arrangement example of the overheat protection device in the conventional air conditioner. As shown in FIG. 6, an electric heater 102 is disposed on the upstream side of the indoor fan case 101, and overheat protection devices 103 and 104 are disposed near and above the electric heater 102. Note that the overheat protection devices 103 and 104 in FIG. 6 are a return type protection device 103 and a non-return type protection device (thermal fuse) 104 as double safety devices.

Thus, the overheat protection device is arranged in the vicinity of the electric heater so as to detect abnormal heating of the electric heater. For example, in Patent Document 1, an electric heater is attached to a partition plate that partitions the suction passage and the discharge passage, and the overheat protection device (temperature fuse) is also inspected and replaced by pulling out the electric heater together with the partition plate. . That is, an overheat protection device is attached in the vicinity of the electric heater. Also in Patent Document 2, an overheat protection device is attached near and above the electric heater.
JP-A-5-71756 (paragraph number 0011) JP 2004-190900 A (FIG. 3)

  However, there are cases where one or both of the suction port and the blowout port are locally blocked such that only the left half or the right half of the suction filter is clogged, and the air flow path is blocked unevenly. In this case, partial abnormal heating occurs in the electric heater, and further, it is difficult to predict a site where abnormal heating occurs. Therefore, especially when the electric heater is long in the width direction of the air conditioner, the installation position and set temperature of the overheat protection device cannot be accurately determined, and detection of abnormal heating of the electric heater by a small number of overheat protection devices Becomes difficult.

  An object of the present invention is to provide an air conditioner capable of preventing overheating of an electric heater even when an air flow path is unevenly blocked.

  In view of the above problems, an air conditioner according to the present invention includes an indoor fan and an electric heater disposed on the upstream side of the indoor fan in the air flow path from the suction port to the blowout port, An overheat protection device for preventing overheating of the electric heater is provided in the air flow path, and a sensing portion of the overheat protection device is provided at a position where the air passing through the air flow path is stirred by the indoor fan.

  According to this configuration, since the sensing unit of the overheat protection device senses the temperature of the air heated by the abnormally heated electric heater after being stirred by the indoor fan, it is assumed that partial abnormal heating has occurred in the electric heater. However, the abnormal heating can be detected regardless of the position where the abnormal heating occurs. As a result, even when the air flow path is unevenly blocked, the overheat protection device can reliably detect and control partial abnormal heating of the electric heater to prevent overheating of the electric heater.

  In the case of adopting a configuration in which an indoor fan case for accommodating an indoor fan is provided in the air flow path, it is preferable to expose the sensing unit of the overheat protection device inside the indoor fan case. Thereby, since the temperature of the air immediately after stirring in the indoor fan case can be sensed, it is possible to more easily sense the temperature rise due to partial abnormal heating of the electric heater.

  The overheat protection device is attached to the mounting hole formed in the indoor fan case from the outer surface side, and the sensing part is exposed from the mounting hole to the inside of the indoor fan case. If it does so, the temperature of the air in an indoor fan case can be sensed by the sensing part of an overheat protection device, without inhibiting the flow of the air in an indoor fan case.

  The overheat protection device may be a non-reset type overheat protection device such as a thermal fuse, but it is more preferable to employ a reset type overheat protection device. Thus, even when abnormal heating occurs in the electric heater, it is only necessary to release the blockage of the air flow path by cleaning the suction filter or the like, and the replacement of the overheat protection device can be made unnecessary. A bimetal thermostat can be illustrated as a reset type overheat protection device. Also, it is possible to adopt either the automatic return type that turns off and on when the temperature rises and falls, and the manual reset type that turns on manually by pressing the reset button after the temperature drops after turning off due to the temperature rise. is there.

  If a second reset type overheat protection device is installed with the sensing unit facing the electric heater, abnormal heating of the electric heater is detected even if the indoor fan stops due to a motor failure or external forcing. be able to.

  That is, when the indoor fan does not move, even if the electric heater is abnormally heated, the heated air does not flow into the indoor fan case. Therefore, in the above overheat protection device with the sensing unit exposed inside the indoor fan case, Unable to detect abnormal heating of electric heater. On the other hand, the abnormal heating of the electric heater can be detected by making the sensing part of the second resettable overheat protection device face the electric heater. Note that the second reset-type overheat protection device need only release the blockage of the air flow path and does not need to be replaced when abnormal heating occurs in the electric heater.

  In addition, the air conditioner according to the present invention may be a hot air heater that heats air only by an electric heater, but may be an air conditioner that includes a refrigerating cycle for air conditioning in addition to an electric heater. it can.

  According to the present invention, since the temperature of the air stirred in the indoor fan case is sensed to detect abnormal heating of the electric heater, the air flow path is non-uniformly closed, resulting in partial abnormal heating of the electric heater. Even so, overheating of the electric heater can be prevented by detecting and controlling the abnormal heating.

  Hereinafter, the best mode for carrying out an air conditioner (air conditioner) according to the present invention will be described with reference to the drawings. 1 is an internal side view of an air conditioner according to the present invention, FIG. 2 is an internal plan view of the air conditioner according to the present invention, FIG. 3 is an exploded perspective view of a heater mounting plate, an electric heater, and an overheat protection device, FIG. FIG. 3 is a front view of a heater mounting plate, an electric heater, and an overheat protection device.

  This air conditioner is an integrated air conditioner having an electric heater 1 for heating and a refrigeration cycle for cooling and heating, and the partition plate 4 standing on the bottom plate 3 built in the housing 2 The internal space is divided into an indoor side chamber 5 and an outdoor side chamber 6, and the indoor side chamber 5 includes an indoor fan (centrifugal fan) 7, an indoor fan case 8, an electric heater 1, a return type overheat protection device 9, and a non-reset type overheat protection. A device (temperature fuse) 10 and an indoor heat exchanger 11 are accommodated, and an outdoor fan (propeller fan) 12, an outdoor fan case 13, and an outdoor heat exchanger 14 are accommodated in the outdoor chamber 6.

  A front cover 15 is attached to the front end (the left end in FIG. 1) of the indoor side chamber 5, and a suction grill 16 as a suction port is formed at the lower part of the front cover 15. Is formed. An indoor fan case 8 that accommodates the indoor fan 7 is disposed at the rear end of the indoor side chamber 5, and an air flow path from the suction grille 16 to the outlet 17 is formed via the indoor fan case 8.

  The indoor fan 7 is rotationally driven by an indoor fan driving motor 18 supported on the rear surface portion of the indoor fan case 8. The indoor fan drive motor 18 is disposed on the outdoor side chamber 6 side, and the drive shaft thereof passes through the rear surface portion of the indoor fan case 8 and is connected to the indoor fan 7.

  The indoor fan case 8 has the rear surface portion of the fan case main body 19 whose front side is opened held by the partition plate 3 and the opening on the front side of the fan case main body 19 is covered by the heater mounting plate 20 to which the electric heater 1 can be attached. Structured. A circular air inlet 21 is formed in a portion of the heater mounting plate 20 facing the indoor fan 7, and the air sucked from the air inlet 21 is discharged from the outlet 22 above the indoor fan case 8 as the indoor fan 7 rotates. It is supposed to exhale.

  Between the indoor fan case 8 and the suction grill 16, an indoor heat exchanger 11 is disposed with a gap 23 in front of the indoor fan case 8, and the condensation dripped from the indoor heat exchanger 11 is disposed below the indoor heat exchanger 11. A drain pan 24 for receiving water is arranged.

  The heater mounting plate 20 has a step-like hanging portion 20a at the upper end and a hook-like hanging portion 20b at the lower end. By placing the hanging portion 20 a on the upper end 11 a of the indoor heat exchanger 11 and engaging the hanging portion 20 b with the drain pan 24, the heater mounting plate 20 covers the opening on the front side of the fan case body 19. Installed. The hanging portion 20a vertically divides the suction passage 25 from the suction grill 16 to the air inlet 21 of the indoor fan case 8 and the air outlet passage 26 from the discharge port 22 of the indoor fan case 8 to the air outlet 17.

  The electric heater 1 has a configuration in which a plurality of heater elements 1a energized by the heater wiring 27 are arranged horizontally and vertically in parallel and supported by support pieces 28 and 29 on both sides in the width direction. The length is set shorter than the width of the heater mounting plate 20. By screwing the support pieces 28 and 29 to the front surface of the heater mounting plate 20 so as to be spaced vertically between the upper portion of the electric heater 1 and the hanging portion 20a of the heater mounting plate 20, the electric heater 1 is Arranged upstream of the indoor fan case 8.

  The reset-type overheat protection device 9 is interposed in series with the heater wiring 27 to prevent overheating of the electric heater 1, and senses the temperature inside the indoor fan case 8 with its sensing unit 9a. When an abnormal heating of the heater 1 is detected, the electric heater 1 is electrically disconnected, and when the temperature inside the indoor fan case 8 decreases, the automatic return type bimetal thermostat is electrically connected again. .

  The reset type overheat protection device 9 is disposed in a space above the electric heater 1 and is screwed to the front surface of the heater mounting plate 20, and the sensing portion 9 a is placed indoors through a mounting hole formed in the heater mounting plate 20. It is exposed inside the fan case 8. As a result, the sensing portion 9a of the return-type overheat protection device 9 is provided at a position where the air passing through the air flow path is agitated by the indoor fan 7. The return-type overheat protection device 9 detects the abnormal heating and electrically disconnects the electric heater 1 and then manually presses the reset button when the temperature inside the indoor fan case 8 decreases. It may be a manual reset type that is electrically connected.

  The non-returnable overheat protection device 10 is for preventing overheating of the electric heater 1, and when the abnormal heating of the electric heater 1 is detected, the electric heater is electrically cut off and the abnormal heating does not lead to ignition. In this way, the final safety of the air conditioner is ensured. This non-returnable overheat protection device 10 is arranged in a space above the electric heater 1 so that the sensing portion 10a faces the electric heater 1, and the front surface of the heater mounting plate 20 via an L-shaped mounting bracket 30. Is attached.

  An outdoor fan case 13 and an outdoor heat exchanger 14 are disposed in the outdoor room 6 from the front, and the outdoor fan 12 is accommodated in the outdoor fan case 13. The outdoor fan 12 is rotationally driven by an outdoor fan driving motor 31 supported by the outdoor fan case 13. In FIG. 2, 32 is an electrical box, and 33 is a compressor.

  Next, a state when the air conditioner is heated by a heater will be described. First, the electric heater 1 is energized and heated, and the indoor fan drive motor 18 is driven and controlled to rotate the indoor fan 7. The indoor air sucked from the suction grill 16 passes through the suction passage 25 to the air inlet 21 and is warmed through the heated electric heater 1 when entering the indoor fan case 8 from the air inlet 21. The air is discharged from the discharge port 22 while being stirred inside the indoor fan case 8, and is blown out from the discharge port 17 through the discharge passage 26 to warm the room.

  Here, a state when the left half (range A in FIG. 2) of the suction grill 16 is closed will be described. Since the left half of the suction grill 16 is closed, the amount of air flowing through the portion overlapping the range A in the air passing through the electric heater 1 is extremely reduced. As a result, the electric heater 1 is partially heated abnormally, and a part of the air entering the indoor fan case 8 from the air inlet 21 is overheated.

  The air inside the indoor fan case 8 is agitated by the indoor fan 7, and the detection unit 9 a of the regenerative overheat protection device 9 exposed inside the indoor fan case 8 senses overheating of the air, and the regenerative overheat protection device 9. Detects abnormal heating of the electric heater 1. Thereby, when the electric heater 1 is electrically disconnected and the temperature inside the indoor fan case 8 is lowered, the electric heater 1 is electrically connected again.

  Even if the abnormal heating of the electric heater 1 is not detected by the return type overheat protection device 9, the non-reset type overheat protection device 10 facing the electric heater 1 ensures the final safety of the air conditioner. Is done.

  According to the above configuration, the air heater 1 is partially agitated inside the indoor fan case 8 and the overheating of the air is detected by the sensing unit 9a of the return type overheat protection device 9. Even when abnormally heated, the abnormal heating can be detected and overheating of the electric heater 1 can be prevented. Thereby, even if any of the many obstruction | occlusion patterns of an air flow path arises, the abnormal heating of the electric heater 1 can be detected without delay.

  In addition, this invention is not limited to said embodiment, A change can be suitably added within the scope of the present invention. For example, as shown in FIG. 5, a second return-type overheat protection device 34 is provided with the sensing portion 34 a facing the electric heater 1, and the indoor fan 7 does not rotate by the second return-type overheat protection device 34. You may make it detect the abnormal heating of the electric heater 1 at the time.

  That is, air does not flow into the indoor fan case 8 when the indoor fan 7 does not rotate due to a failure of the indoor fan drive motor 18 or an external forcing force. In this case, the return-type overheat protection device 9 in which the sensing unit 9a is exposed inside the indoor fan case 8 cannot detect abnormal heating of the electric heater 1, but the second return-type overheat protection device 34 can Abnormal heating of the heater 1 can be detected.

  By providing the second return-type overheat protection device 34, it is not necessary to operate the non-reset-type overheat protection device 10 for ensuring final safety, and the non-return-type overheat protection device 10 is replaced at the time of service. Can be made unnecessary.

  The air conditioner according to the present invention is not limited to an air conditioner having a refrigeration cycle for air conditioning, and may be a hot air heater that heats air only by an electric heater. Furthermore, it is also possible to employ a configuration in which an indoor fan is directly provided in the air flow path without providing an indoor fan case. In the case of adopting this configuration, the return type overheat protection device 9 may be provided at a position where air is stirred by the indoor fan.

Internal side view of an air conditioner according to the present invention Internal plan view of an air conditioner according to the present invention Exploded perspective view of heater mounting plate, electric heater and overheat protection device Front view of heater mounting plate, electric heater and overheat protection device Front view of heater mounting plate, electric heater and overheat protection device of another embodiment The figure which shows the example of arrangement | positioning of the overheat protection apparatus in the conventional air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric heater 7 Indoor fan 8 Indoor fan case 9 Reset type overheat protection device 9a Sensing part 10 Non-reset type overheat protection apparatus 10a Sensing part 16 Suction grill 17 Outlet 20 Heater attachment plate 34 2nd reset type overheat protection apparatus 34a Sensing Part

Claims (6)

  In an air conditioner including an indoor fan and an electric heater disposed upstream of the indoor fan in an air flow path extending from the suction port to the outlet, the air flow path is prevented from being overheated. An air conditioning apparatus comprising: an overheat protection device, wherein a sensing unit of the overheat protection device is provided at a position where air passing through the air flow path is agitated by the indoor fan.   The indoor air case that houses an indoor fan is provided in the air flow path, and the sensing unit of the overheat protection device is provided to be exposed inside the indoor fan case. Air conditioning device.   3. The air conditioner according to claim 2, wherein the overheat protection device is attached to an attachment hole formed in the indoor fan case from an outer surface side, and the sensing unit is exposed to the inside of the indoor fan case from the attachment hole. apparatus.   The air conditioner according to claim 1, 2 or 3, wherein the overheat protection device is a resettable overheat protection device.   The air conditioner according to any one of claims 1 to 4, wherein a second return-type overheat protection device is provided with a sensing unit facing the electric heater.   The air conditioner according to any one of claims 1 to 5, wherein the air conditioner is provided with a refrigeration cycle for air conditioning.

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