JP2577318Y2 - Air conditioner - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly, to an air conditioner having an overheat preventing function for electric components such as power transistors which generate a large amount of heat.

[0002]

2. Description of the Related Art In recent years, particularly in air conditioners, a variable compression capacity type device having an inverter control device has been widely used as a highly economical device. One of the important issues is to prevent overheating of the provided power transistor, and various improvements have been made for this purpose.

In order to prevent overheating of a power transistor, which has been conventionally attempted in an air conditioner, a cooling method using heat loss by a low-temperature refrigerant pipe (for example, Japanese Utility Model Application Laid-Open No. HEI 2-102).
No. 4163), and an air cooling method using air blowing at the time of air blowing operation of a heat exchanger fan. The former is difficult to be put into practical use due to problems such as manufacturing cost and dew condensation, and the latter is generally used. It has become.

[0004]

Some air conditioners are designed to perform indoor dehumidification by selecting a hot air dry operation mode as well as a cooling / heating operation mode. This is an operation in which condensation is performed on the upstream side of an indoor heat exchanger divided vertically and evaporation is performed on the downstream side, cooling and dehumidifying indoor air, and heating it to return it indoors. It has an aspect. As a measure for preventing overheating of the power transistor provided in the outdoor unit of the air conditioner, if the latter method described above, that is, an air cooling method using air blowing at the time of air blowing operation of the heat exchanger fan is adopted, the power transistor is air-cooled. In the hot air dry operation mode, it is necessary to perform the air blowing operation of the heat exchanger fan. In such a case, the temperature of the airflow blown out from the indoor unit decreases, and the hot air dry operation is not performed. Therefore, when the fan is stopped in the hot air dry operation mode, there is a problem that the air cooling of the power transistor is not performed and the power transistor is easily overheated.

The present invention has been made in order to solve the above-mentioned conventional disadvantages, and has as its object to prevent the normal operation in a hot air dry operation mode or the like, and to generate heat-generating electric components such as a power transistor. An object of the present invention is to provide an air conditioner that can prevent overheating of the air conditioner by an air cooling system.

[0006]

Means for Solving the Problems] where the air conditioner of this invention, as in the warm air drying operation for performing both the evaporation and condensation in the indoor heat exchanger, an outdoor heat exchanger refrigerant in ventilation suppression state In an air conditioner having a specific operation mode for circulating inside the air conditioner 1, the outdoor propeller fan 3
The cross-sectional shape along the direction of rotation of the propeller is on the rear side in the normal rotation direction.
Curved smoothly so that it protrudes forward in the blowing direction
It has a shape with the front and back of the shape, so that the shaft is
While it produces a flow, when it reverses, its rotation turns it into air.
Configuration to give centrifugal force to generate air flow by centrifugal force
And also in the specific operation mode, the fan rotation switching means MR2 rotate in opposite directions provided the outdoor propeller fan 3 and the forward state to rise to axial flow, air flow by the centrifugal force by the reverse rotation of the propeller fan 3 Is characterized in that a heat generating portion 5 of a heat generating electric component such as a power transistor is disposed in a region where the heat generation occurs.

[0007]

[Action] In the above air conditioner, Te warm air dry operation mode odor, outdoor propeller fan 3 rotates in the reverse direction. In this state, the ventilation to the outdoor heat exchanger 1 is reliable.
Although is suppressed, the air flow is occurring by centrifugal force during the reverse rotation of the propeller fan 3, the heat-generating electrical component is cooled in contact with the heat generating portion 5 of the heat generating electrical components such as power transistors.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the interior of an outdoor unit of an air conditioner according to an embodiment of the present invention. In the figure,
1 is an outdoor heat exchanger, 2 is a fan motor, 3 is an outdoor propeller fan, 4 is an electrical component box containing a power transistor, which is an example of a heat generating electric component, and 5 is a cooling fin protruding from a heat generating surface of the power transistor. , 6 are housings, and the fins 5 are located near the outer periphery of the propeller fan 3,
That is, the propeller fan 3 is installed in a region where an air flow is generated. The installation part 7 of the electrical component box 4 containing the power transistor and the like, and the equipment installation room 8 such as the heat exchanger 1 and the propeller fan 3 are separated by the partition plate 9 and the fins 5 serve as the power transistor. The heat generating part extends into the equipment installation room 8.

The propeller 31 forming the propeller fan 3 has, for example, a cross-sectional shape curved in one direction as shown in FIG. That is, as shown in the figure, the outdoor propeller
The fan 3 has a sectional shape along the direction of rotation of the propeller,
So that the rear side in the forward rotation direction projects forward in the air blowing direction
Make it a shape with a smoothly curved front and back,
In the case of forward rotation, axial flow is generated, while in the case of reverse rotation,
The centrifugal force is given to the air by rolling,
It is configured to occur. More specifically, FIG. 3 shows an arrow A indicating the direction of movement of the propeller 31 when the propeller fan 31 rotates in the forward direction, and an arrow B indicating the direction of movement of the propeller 31 when the propeller fan 31 rotates in the reverse direction.
Indicated by According to the propeller fan 3 having the propeller 31 having the above-described shape, when the propeller fan 31 rotates in the forward direction and the propeller 31 moves in the direction indicated by the arrow A, the air pushed by the propeller 31 is changed to the solid arrow a.
As shown by, the internal pressure rise is large enough to flow with a large turning angle, and the normal air blowing operation for the heat exchanger 1 is performed. On the other hand, when the propeller fan 31 rotates in the reverse direction and the propeller 31 moves in the direction shown by the arrow B, the air pushed by the propeller 31 has almost no turning angle as shown by the broken arrow b. Therefore, the internal pressure rise is not obtained, so that the air is hardly blown to the heat exchanger 1, and the heat exchanger 1 hardly functions.

FIG. 3 shows an example of an electric circuit capable of switching the fan motor 2 between a forward rotation mode and a reverse rotation mode. In the figure, MR1 is an air flow setting relay for switching the rotation speed of the fan motor 2 between a high speed H and a low speed L, and MR2 is a rotation direction setting for switching the rotation direction of the fan motor 2 between a forward direction and a reverse direction. Relay (fan rotation switching means), C is a condenser. In such an electric circuit, a circuit including the air volume setting relay MR1 has been conventionally existing, and a circuit in which a rotation direction setting relay MR2 is added to such an electric circuit is shown in FIG. It is. Therefore, this electric circuit
It can be configured simply by adding the rotation direction setting relay MR2 to the conventional electric circuit, so that it is inexpensive.

In the outdoor unit having the propeller fan 3 and the electric circuit described above, in the cooling / heating operation mode, the rotation direction setting relay MR2 of the electric circuit is set to the forward direction, and the propeller fan 3 is moved in the forward direction. By rotating, air is blown to the heat exchanger 1, and the heat exchanger 1 functions as a condenser or an evaporator. As described above, when the propeller fan 3 is rotating in the forward direction, an air flow is generated due to the forward rotation of the propeller fan 3, and the air flow contacts the fins 5 to cool the heat generating portion of the power transistor. You.

When the hot air dry operation mode is set, the rotation direction setting relay MR2 of the electric circuit is set to the reverse direction, and the propeller fan 3 rotates in the reverse direction. Therefore, the air is hardly blown to the heat exchanger 1, so that the heat exchanger 1 does not function as a condenser. In other words, stable hot air dry operation is continuously performed.
As described above, even when the propeller fan 3 is rotating in the reverse direction, an air flow is generated around the propeller fan 3 due to the centrifugal force associated with the reverse rotation of the propeller fan 3. Thus, the heat generating portion of the power transistor is air-cooled. In the hot air dry operation mode described above, an indoor heat exchanger (not shown) is divided into an upstream side and a downstream side, and a condensation operation is performed on the upstream side and an evaporation operation is performed on the downstream side. This is an operation mode in which room air is cooled and dehumidified, then heated and returned to the room.

In this embodiment, a power transistor is exemplified as the heat-generating electric component. However, it is needless to say that the present invention can be applied to air-cooling of a heat-generating electric component other than the power transistor. Furthermore, although the example of application in the hot air dry operation mode is described above, the invention is similarly applicable to the defrost operation mode in which a high-temperature gas refrigerant is introduced into the outdoor heat exchanger 1.

[0014]

According to the air conditioner of the present invention, not only when the propeller fan is in the blowing operation but also when the propeller fan does not need to perform the blowing operation, the propeller fan rotates in the reverse direction. it is possible to cool the heat-generating electrical component such as a power transistor in an air flow generated by the centrifugal force. Therefore, it is possible to air-cool heat-generating electrical components such as power transistors while reliably suppressing airflow to the outdoor heat exchanger of the air conditioner , thereby enabling continuous and stable hot-air dry operation. Has the effect of becoming

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating the operation of a propeller fan with respect to a propeller.

FIG. 3 is an electric circuit diagram used in the above.

[Explanation of symbols]

 Reference Signs List 1 outdoor heat exchanger 3 propeller fan MR2 rotation direction setting relay (fan rotation switching means)

Claims (1)

(57) [Scope of request for utility model registration] [Claim 1] As during both warm air dry operation to perform the condensation at the indoor heat exchanger and the evaporator, including the specific operation mode for circulating refrigerant outdoor heat exchanger (1) in the ventilation suppression state Of the outdoor propeller fan
(3) is that the cross-sectional shape along the rotation direction of the propeller is positive.
Slip so that the rear side in the rolling direction projects forward in the blowing direction.
It has a shape that has a curved front and back,
In the case of forward rotation, axial flow is generated, while in the case of reverse rotation,
To apply centrifugal force to the air to generate airflow due to the centrifugal force.
And in the specific operation mode,
The outdoor propeller fan (3) and forward states that occur axial flow provided the fan rotation changeover means for rotating in the reverse direction (MR2), the air flow is caused by the centrifugal force by the reverse rotation of the propeller fan (3) An air conditioner, wherein a heat generating portion (5) of a heat generating electric component such as a power transistor is disposed in a region.