JPH0639960B2 - Propeller fan for air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a propeller fan for an air conditioner, and more specifically, to a fan body having a plurality of blades around a hub and a fan guide. The present invention relates to a propeller fan in which a heat exchanger in an air conditioner is arranged on the suction side of the propeller fan.

(Prior Art) For an outdoor unit of an air conditioner, for example, the actual opening 6
As described in Japanese Patent Application Laid-Open No. 0-111466, a heat exchanger and a propeller fan are arranged inside the casing so as to face each other, and the outside air sucked from the outside of the casing due to the rotational driving of the propeller fan is used as the heat exchanger. The heat exchanger is brought into contact with the outside air so as to exchange heat with the outside air.

As a propeller fan used as described above, generally, as shown in FIG. 6, a plurality of blades (32) are provided around the outer periphery of a hub (31) to form a fan body (3). A cylindrical fan guide (4) is arranged at a position radially outward of the blades (32) in the fan body (3).

(Problems to be Solved by the Invention) By the way, when the internal resistance of the fan body (3) changes due to conditions such as frosting of the heat exchanger, the flow rate to be operated changes accordingly. However, during operation of the fan body (3) in the low flow rate region, air is blown out from the hub side of the fan body (3) in the anti-centripetal direction as indicated by the solid arrow in FIG. However, at this time, a vortex (a) as shown by the solid line in the figure is generated at the outlet of the fan guide (4) at the front position in the air blowing direction.

Also, during operation of the fan body (3) in the high flow rate range,
As shown by the phantom line arrows in FIG. 6, the fan body (3)
The air is blown from the outer side in the radial direction toward the centripetal side.At this time, the vortex flow shown by the phantom line in the air blowing direction at the outer peripheral portion of the fan body (3) is located at the front position in the air blowing direction.
(b) occurs.

Therefore, the static pressure characteristics of the propeller fan, that is, the fan efficiency is deteriorated by the vortex flows (a) and (b) generated when the fan body (3) is operated in the high and low flow rate regions, and the specific noise is also increased. There was a problem.

The present invention has been made in view of the above problems, and an object thereof is to suppress the generation of each of the vortex flows by adding a simple improvement to the fan main body, and to reduce static pressure and specific noise characteristics of a propeller fan. Is to raise.

(Means for Solving Problems) The propeller fan of the present invention is configured as shown in the drawings, and includes a fan body (3) having a plurality of blades (32) around the outer periphery of a hub (31) and a fan. A propeller fan consisting of a guide (4) and having a heat exchanger in an air conditioner arranged on the suction side of the fan body (3), at the outlet side of the fan guide (4), the centripetal direction Is provided with a movable guide portion (5) that can be switched between a first guide position along the flow of No. 2 and a second guide position along the flow in the anticentric direction, and is provided for detecting the frosted state of the heat exchanger. Frost detection sensor
It is characterized in that a switching control means for switching the movable guide portion (5) between the first guide position and the second guide position based on the detection signal from (6) is provided.

(Operation) Then, when the propeller fan is operated in a high flow rate range, the movable guide portion (5) is switched to the first guide position by the switching control means, and the fan body (3) is switched by the guide portion (5). ) Is guided in the centripetal direction, and during operation of the propeller fan in a low flow rate range, the movable guide portion (5) is switched to the second guide position, and the guide portion (5 The air blown out from the fan body (3) is guided in the anti-centripetal direction by (1). In other words, the movable guide portion (5) is switched according to the operating state of the propeller fan, and the air from the fan body (3) is rectified by the guide portion (5) and blown out to the outside. Therefore, the generation of the vortex flow at the front position of the fan body (3) in the air blowing direction is suppressed, and the static pressure characteristic and the specific noise characteristic of the propeller fan are enhanced.

(Embodiment) A propeller fan for an air conditioner according to the present invention will be described below with reference to an embodiment of the drawings.

FIG. 1 shows an outdoor unit of an air conditioner, in which a heat exchanger (2) is arranged at one open side of a casing (1) whose both sides in the flow direction are open, and the other side of the casing (1) is open. A propeller fan, which will be described later, is arranged at a position opposed to the heat exchanger (2) in a part.

The propeller fan includes a fan body (3) formed by circumferentially providing a plurality of blades (32) extending outward in the radial direction on the outer periphery of a hub (31), and an opening on the other side of the casing (1). Said feather (3
The fan main body (3) is composed of a cylindrical fan guide (4) integrally formed outwardly at a position facing the (2).
Along with the rotational driving of the outside air is introduced from one side opening portion of the casing (1), blows out from the fan guide (4) to the outside through the heat exchanger (2), and the outside air and the heat exchanger.
By contacting with (2), heat is exchanged in the heat exchanger (2).

Then, in the propeller fan as described above, it is possible to switch between the first guide position along the flow in the centripetal direction and the second guide position along the flow in the anticentric direction on the air outlet side of the fan guide (4). A switch for switching the movable guide part (5) to the first and second guide positions according to the air flow at the outlet of the fan body (3) while providing the movable guide part (5). The control means is provided.

As is apparent from FIG. 2, the movable guide portion (5) includes a plurality of trapezoidal members (5a) made of a shape memory alloy and a plurality of triangular members (5b) made of a stretchable material such as rubber or integrally molded. By using this triangular member (5b) or an integrally molded annular member by adhesively interposing between the trapezoidal members (5a), the fan member (3) is formed into the same cylindrical shape. The movable guide portion (5) thus formed is integrally attached to the outer end portion of the fan body (3).

The switching control means for switching the movable guide portion (5) to the first and second guide positions detects the frosted state of the heat exchanger (2) inside the casing (1). Using the provided detection sensor (6) and a heater (not shown), the heater is connected to and supported by each of the trapezoidal members (5a) formed of a shape memory alloy, and the heater is used as the detection sensor. The trapezoidal member (5a) is connected to (6) and the heater is controlled by a detection signal from the sensor (6).
That is, the movable guide portion (5) is switched to the first and second guide positions.

Thus, for example, frost or the like adheres to the heat exchanger (2) to increase the in-machine resistance in the casing (1), and when the propeller fan is operated in a low flow rate range, from the fan body (3). The blown air is blown out from the hub side of the fan main body (3) in the direction opposite to the centripetal direction, as shown by the solid arrow in FIG. 1. At this time, the detection sensor (6) passes through the heater. A detection signal is output to heat the heater, and the heating of the heater causes the movable guide portion (5) to be elastically deformed as shown in the practice of FIG.
It is moved to the guide position. Therefore, the fan body
The air blown out from (3) is rectified by the movable guide portion (5) and guided in an anticentric direction.

Further, when the propeller fan is operated in a high flow rate range, the air blown from the fan body (3) is directed from the radial outside of the fan body (3) to the centripetal direction as shown by the imaginary line arrow in FIG. The heater is held in a non-heated state by the detection signal from the detection sensor (6) at this time, and the movable guide portion (5) is indicated by a phantom line in FIG. It is held at 1 guide position,
Therefore, the air blown from the fan body (3) is rectified by the movable guide portion (5) and guided in the centripetal direction.

In the embodiment, the movable guide portion (5) is formed in a tubular shape by the trapezoidal member (5a) made of a shape memory alloy and the triangular member (5b) made of a stretchable material.
(5) can also be formed as shown in FIG.

That is, the cylindrical body (5c) having the same inner diameter as the fan guide (4).
And the cylindrical body (5c) is supported at an outer position of the fan guide (4) via a movable spring (5d) made of a plurality of shape memory alloys. Attach a heater in the same manner as above and connect the sensor (6) to the heater.

Thus, during operation of the propeller fan in the low flow rate range,
The movable spring (5d) is detected by the sensor (6).
By extending the cylinder body (5c) is held by the second guide (1) separated from the fan guide (4) as shown by the solid line in FIG. 3, and in the high flow rate range of the propeller fan. During operation, the movable body (5d) is contracted by the detection signal from the sensor (6), thereby the tubular body (5c).
Is held at the first guide position on the fan guide (4) side as shown by the phantom line in FIG.

In the embodiment, a shape memory alloy is used as a component of the movable guide portion (5), but in the present invention, a piezoelectric ceramic is used instead of the shape memory alloy, and a voltage change to the piezoelectric ceramic causes The movable guide portion (5) may be moved to the first and second guide positions.

In FIG. 1, (M) is a motor for driving the fan body (3) arranged inside the casing (1).

Next, static pressure characteristics and specific noise characteristics of the propeller fan according to the present invention and a conventional propeller fan will be described based on the test results shown in FIGS. 4 and 5.

FIG. 4 shows a static pressure curve in which the horizontal axis represents the flow rate Q and the vertical axis represents the static pressure Ps. As is clear from this figure, in the propeller fan of the present invention, the static pressure with respect to the flow rate is the conventional one. It can be understood that the static pressure characteristics, that is, the fan efficiency, are higher than those of the conventional products.

Further, FIG. 5 shows a specific noise curve in which the horizontal axis represents the flow rate Q and the vertical axis represents the specific noise DBS. As is clear from this figure, in the propeller fan of the present invention, the specific noise with respect to the total flow rate is It is understood that it is extremely low and has excellent specific noise characteristics.

(Effects of the Invention) As described above, in the propeller fan according to the present invention, on the outlet side of the fan guide (4), the first guide position along the flow in the centripetal direction and the second guide position along the flow in the anticentric direction are provided.
A movable guide part (5) that can be switched to a guide position is provided, and the guide part (5) is provided based on a detection signal from a frost detection center (6) provided to detect the frosted state of the heat exchanger. Since the switching control means for switching 5) between the first guide position and the second guide position is provided, frost adheres to the heat exchanger, increasing the in-machine resistance in the casing of the air conditioner, and operating in the low flow rate region. Even if the movable guide
(5) is the second direction opposite to the blowing direction at this low air volume
It is automatically switched to the guide position, so that the blown air can be blown out without being swirled by being rectified by the guide portion (5), and therefore the static pressure characteristics of the propeller fan are not deteriorated. It can be operated efficiently and with less noise, and when the frost of the heat exchanger is defrosted, the internal resistance is reduced, and when operating at a high air volume, the guide part (5) is Since it is automatically switched to the first guide position in the direction corresponding to the blowing direction at the time of high air volume and the correction is made to the blowing direction, even at this high air volume, the static pressure does not decrease efficiently, and
You can drive with less noise.

Therefore, in any case, it is possible to minimize the generation of eddy currents on the air outlet side of the fan body (3), and it is possible to improve the static pressure characteristics and the specific noise characteristics of the propeller fan.

[Brief description of drawings]

FIG. 1 is a side sectional view of an air conditioner equipped with a propeller fan of the present invention, FIG. 2 is a front view showing a movable guide portion, and FIG.
FIG. 4 is a side sectional view showing another embodiment, FIG. 4 is a drawing showing static pressure characteristics, FIG. 5 is a drawing showing specific noise characteristics, and FIG. 6 is a drawing explaining a conventional example. (2) …… Heat exchanger (3) …… Fan body (31) …… Hub (32) …… Blade (4) …… Fan guide (5) …… Movable guide section

Claims (1)

[Claims] 1. An air conditioner comprising a fan body (3) having a plurality of blades (32) around a hub (31), and a fan guide (4), the suction side of the fan body (3). A propeller fan in which a heat exchanger is arranged in the first guide along the flow in the centripetal direction on the outlet side of the fan guide (4).
In addition to providing a movable guide portion (5) that can be switched between a guide position and a second guide position along the flow in the anticentric direction,
Based on the detection signal from the frost detection sensor (6) provided to detect the frosted state of the heat exchanger,
A propeller fan for an air conditioner, comprising a switching control means for switching between a guide position and a second guide position.