JPS58158400A - Propeller fan - Google Patents

Abstract

PURPOSE:To enable to increase the air volume of a propeller fan automatically with rising of the ambient temperature while keeping the speed of rotation of the fan constant, by storing such a torsional deformation in blades of the fan made of a shape memory alloy that the setting angle of the blades is small when the ambient temperature is low but it is increased when the ambient temperature is high. CONSTITUTION:A propeller fan of this invention comprises blades 1 obtained by stamping out a plate made of a shape memory alloy scuh as nickel and titanium into the form of an aerofoil. The blades 1 are fixed a bearing 5. According to the present invention, such a form is stored in the blades 1 that the setting angle of the blades 1 is decreased when the ambient temperature is low while it is increased when the ambient temperature is high. By employing such an arrangement, it is enabled to obtain a propeller fan capable of increasing its air capacity automatically along with the temperature rise while keeping the speed of rotation of the fan constant. For instance, in case that it is used as a fan for a consolidated air-conditioner, the setting angle of the blades is increased and the air capacity is increased resultantly with increasing of the atmospheric temperature even if it is operated at first at a low speed. Therefore, it is enabled to protect the motor for driving a compressor and to prevent deterioration of lubricating oil by enhancing the heat exchanging performance of a condenser and thereby lowering the condensation pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propeller fan used in an air conditioner or the like.

Conventionally, propeller fans used in air conditioners, etc. have a configuration in which a hub a and two bearing blades C are fixed to each other, as shown in Figures 1 and 2. Yes, the air volume was changed by changing the rotation speed. FIG. 3 shows a case where the propeller fan A is mounted on an air conditioner B.

In the figure, C is a fan motor, and the propeller fan A and sirocco fan D are fixed coaxially.

Compressor E + tM = compressor F, 9 compressors, 29 capillary devices H are connected in this order with piping to constitute a refrigeration cycle. The fan motor C is operated at a high rotation speed when the load is high and the wet and dry bulb temperature is high both indoors and outdoors, and at a low rotation speed when the load is low both indoors and outdoors.

However, with this structure, if the indoor temperature is low and the outdoor temperature is high, the user will have to use the engine at a low rotation speed.
In this case, the condensing pressure will become very high, the motor winding temperature of the compressor E will become too high, the lubricating oil will deteriorate, and not only will the life of the compressor E be shortened, but the overload protection device will simply This had the disadvantage that the air conditioner was frequently interrupted due to the operation.

The present invention eliminates the above-mentioned conventional drawbacks.

Hereinafter, the present invention will be explained based on FIGS. 4 to 7.

In Figs. 4 to 6, reference numeral 1 denotes a blade plate made of a shape memory alloy constituting a propeller fan, which is stamped into the shape of four blades 3. The central part thereof has a through hole 1a, and 2 It is sandwiched between two washers 2 and a cushioning material 3.4, and is caulked and fixed to a bearing 6.

In this propeller fan, as shown in Fig. 7, the blades 1 are made of a shape memory alloy that reversibly changes shape depending on the ambient temperature, and when the ambient temperature is low, the cross-sectional shape of the blades 1 changes. When installed □ as shown by the solid line A, the angle will be α.

When the ambient temperature is high, the cross-sectional shape of the vane 1 twists and changes to the shape B shown by the broken line, and the angle of attachment becomes large with β.

Therefore, even if the rotation speed does not change, the propeller fan produces a small air volume when the ambient temperature is low and a large air volume when the ambient temperature is high.

As is well known, shape memory effect alloys are made of alloys of nickel, titanium, copper, zinc, etc., and the method for forming propeller fans is to hot-roll an alloy with a composition that shows the desired transformation temperature into a thin sheet. Then, the thin plate was punched out to obtain a wing plate material. child? =ifJaa58-158400
Insert the wing plate material (2) into the stainless steel mold so that the installation angle is slightly larger than β in Fig. 7, and
After heating to SOO° C. and quenching, it was fitted into a mold with an angle of α and heated to a temperature above the austenite transformation end temperature to perform shape memory treatment. Reversible shape memory processing may be performed using other methods.

Further, the means for supporting and fixing the vane plate 1 to the bearing 6 is fixed by caulking in the embodiment, but the same effect can be obtained by fixing by other means such as adhesion, screwing, welding, or press fitting.

Furthermore, as shown in FIG. 8, when the ambient temperature is low, the warpage of the blade 1 is small as shown by the solid line A, and when the ambient temperature is high, the warp of the blade 1 is large as shown by the broken line B. The same effect can be obtained even if the blades are attached at different angles.

As is clear from the above embodiments, the propeller fan of the present invention has blades made of a shape memory alloy stamped into the shape of a blade fixed to a bearing, and if the ambient temperature is low, the blades can be attached. The corners become smaller, and when the ambient temperature is high, the blades are installed so that the corners become sharper.
This makes it possible to create a propeller fan that automatically increases air volume while keeping the rotation speed constant as the temperature rises.Since the rotation speed is constant, control is extremely simple; When used as a blower, a single motor drives both indoor and outdoor fans.
Even when operating at low rotation speeds, if the outside temperature rises, the angle of the blade installation increases, increasing the air volume, increasing the heat exchange capacity of the condenser, lowering the condensing pressure, and reducing the compressor motor. It is possible to prevent the deterioration of lubricating oil, eliminate the inconvenience caused by single-acting overload protection devices, and provide a blower structure with a wider operating range, lower noise, and longer life. It can be punched and formed from a single plate, requires fewer assembly steps, and can be fixed in the same way as before, so it can be produced at low cost with fewer parts and has various advantages, such as a propeller fan with fewer failures. It has the following.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a conventional propeller fan, Fig. 2 is a front view of the propeller fan, Fig. 3 is a schematic configuration diagram of an air conditioner equipped with the propeller fan, and Fig. 4 is the invention of the present invention. A plan view of a propeller fan in one embodiment, FIG. 6 is a partially sectional front view of the propeller fan, FIG. 6 is a sectional view of the blade fixing part of the propeller fan, and FIG. 7 is a diagram of the propeller fan. FIG. 8 is a cross-sectional view of a blade in another embodiment of the present invention. 1... Wing plate, 3, 4... Cushioning material, 5.
·····bearing. Name of agent: Patent attorney Toshio Nakao and one other person St.
Figure 3 Figure 4 Figure 7 Figure 8

Claims (1)

[Claims] A blade made of a shape memory alloy punched into the shape of an airfoil is fixed to the bearing.If the ambient temperature is low, the blade will be installed at a smaller angle, and if the ambient temperature is high, the blade will be installed. is a propeller fan that has a memorized shape with larger corners.