JPH0442582B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention is a wind direction switching device that is disposed in the air path of an air conditioner and heater to change the wind direction.In particular, the device uses the wind blowout temperature as the power to move the variable blades for changing the wind direction. The present invention relates to a wind direction switching device for air conditioners that blows cold air upward and hot air downward, using a shape memory alloy that changes the air flow. Conventional configurations and their problems Conventionally, in heat pump type air conditioners, variable air direction blades are arranged so that the air blows upwards during cooling and downwards during heating, and the changeover is performed manually. In recent years, by utilizing the properties of shape memory alloys (hereinafter referred to as SMA), which change their shape above or below a predetermined temperature, variable blades are automatically operated in response to the air temperature, allowing cold air to flow upward and warm air to flow upward. A device that blows out downward has been devised. On the other hand, when using this SMA, sufficient consideration must be given to the error in the transformation temperature. That is,
The above SMA is as shown in Table 1 below,
If the composition ratio of the constituent elements that make up this alloy or the amnestic treatment temperature that memorizes the predetermined shape deviates even slightly, the transformation temperature will change. There are some that are off by a maximum of 10 to 20 degrees Celsius. Therefore, it is clear that in actual use, it is necessary to keep the variation in the transformation temperature of the SMA within a problem-free range.

【table】

[Table] In other words, in order to automatically vary the variable blade using SMA, it cannot be put into practical use simply by interlocking the SMA and the variable blade, and it is essential to have a means to compensate for variations in the transformation temperature of the SMA. This is a necessary condition. Parts 7 to 8 are specific configurations that take this into consideration.
The one shown in the figure can be considered. In this figure, a
is an automatic wind direction switching device using a shape memory alloy installed at the air outlet of an air conditioner/heater, and is installed to sense the air passage temperature within the air path of the air conditioner/heater. a rotating shaft c, an operating rod e that protrudes rearward from one end of the wing b and has a partially hollowed out hole d in the form of an ellipse, a guide rod f passing through the hole d, and a guide rod. A coil spring g made of a shape memory alloy and a coil spring g arranged to surround f and actuate the operating lever e.
and a bias coil spring h provided in opposition to the. the two coil springs g,
The springs h are provided above and below the operating rod e, and have operating protrusions i and j at the tips of the springs that closely slide on the operating rod e. Further, the guide rod f is fixed to a frame m having fixing points k and l at the top and bottom, and the frame m is attached to a side wall of the air conditioner or the like with screws n or the like. Next, the operation of the above configuration will be explained. The air conditioner is operated for heating, and the above-mentioned SMA coil spring g is heated by hot air.
When it is heated and reaches the transformation temperature (approximately 30°C) or higher, it generates a large force and expands as shown in Fig. 7, compressing the opposing coil spring h and pushing up the operating rod e, which causes the wing b to move toward the rotation axis c. Rotate it around the center and tilt it forward and downward. Therefore, the hot air is blown downward as shown by the arrow. Here, as long as the SMA coil spring g is kept at a temperature above its transformation point, it maintains an expanded state in balance with the repulsive force of the compressed normal bias coil spring h that is in contact with it. However, when the heating operation is stopped or the SMA coil spring g becomes below the transformation temperature due to the cooling/heating operation, the SMA coil spring g contracts due to the repulsive force of the compressed ordinary coil spring h, resulting in wing b. slopes upward in front,
Cold air blows upward. On the other hand, when the above-mentioned variation in the transformation temperature of the coil spring g occurs, there is no choice but to take measures such as providing a mechanism for adjusting the spring force of the above-mentioned ordinary coil spring h. This is extremely disadvantageous because it is mechanically complicated and impractical to employ such a means at the air outlet of an air-conditioner or heater, and for the reasons described below. In other words, when considering the amount of displacement of both coil springs g and h and the generated force, there is a relationship shown in FIG. 9. In this figure, when the SMA type coil spring g generates a force F _O at a predetermined temperature T above the transformation point, the force F _O of the coil spring h required at the initial setting overcomes the force of the built-in coil spring h, and the curve a _O As the amount of displacement increases, the generated force decreases. However, on the other hand, the coil spring h facing this
As shown by the straight line b _O , the generated force increases as the displacement increases, and finally at the intersection P, the force is balanced by the SMA coil spring g and the force F _x (F _x > f _O ), and the displacement Δl is obtain. Therefore, in the above embodiment,
If the amount of displacement of the SMA coil spring g is required to be Δl at a predetermined temperature T above the transformation point, a spring design was required that would generate a force F _x (>f _O ) at the time of displacement Δl. Therefore, the SMA coil spring g requires a relatively large spring, which has the drawback of making it extremely expensive. OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide an automatic wind direction switching device for an air conditioner/heater that has an extremely simple structure, eliminates the above-mentioned conventional drawbacks, and has excellent temperature accuracy at a low cost. Structure of the Invention In order to achieve this object, a coil spring made of a shape memory alloy is placed at one end of the variable blade so that the variable blade placed in the air path can be moved up and down at a predetermined temperature, and the load applied to the coil spring is placed at one end of the variable blade. It has a weight that can adjust the distance from the rotation axis of the variable blade to change the temperature of the SMA coil spring. (a property that varies considerably between production lots) and keeps the operating temperature of SMA coil springs within a range that does not cause any practical problems. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In Figures 1 to 4, 1 is a ceiling-mounted heat pump air conditioner, 2 is the main body, and 3 is the main body 2.
4 is a fan, 5 is an evaporator, 6 is a heater, 7 is an air outlet provided on the front side of the main body 2, 8 is an automatic wind direction switching device of the present invention, 7. Reference numeral 9 denotes a variable blade provided over the entire width of the main body 2, and both ends of its rotating shaft 9' are rotatably fixed to the side wall of the main body 2. A balance rod 10 is extended and fixed to one rear end of the variable blade 9, and has a threaded portion 11 at its tip. Further, a weight 12 is screwed into the threaded portion 11. The weight 12 is rotated and moved back and forth, so that the distance between the variable blade 9 and the rotation axis 9' can be adjusted. A part of the balance rod 10 has an oval opening 13.
A guide rod 14 is provided in this opening 13.
is penetrated and fixed at upper and lower fixing points 15 and 16. A coil spring 17 made of SMA is provided between the balance rod 10 and the lower fixing point 16 so as to surround the guide rod 14, and further has an operating protrusion 18 on the coil spring 17 that comes into contact with the balance rod 10 and slides thereon. The above-mentioned SMA is made of the metal elements shown in Table 1 above, and has the property of generating a large force at the same time as it attempts to return to its original shape when it reaches a certain predetermined temperature (transformation temperature). ing. In this embodiment, the SMA coil spring 17 remembers a state in which it has been stretched to a predetermined length, and when it is heated and reaches a transformation temperature (approximately 30°C) or higher, it is subjected to the load of the weight 12 as shown in Fig. 3. Overcome and grow. In addition, SMA has the property that it has high material strength above its transformation temperature (high temperature phase), but its strength decreases when it cools down to below the transformation temperature (low temperature phase). 17
When the temperature drops below the transformation temperature, it is compressed as shown in FIG. 2 due to the load of the weight 12. Next, the operation will be explained. With the above configuration, when the ceiling-mounted heat pump air conditioner 1 is operated for cooling, the cold air (10 to 15°C) causes the SMA to
As the coil spring 17 is cooled, it becomes compressed as shown in FIG. 2, and the variable blades 9 tilt upward, so that cold air is blown upward as shown by the solid arrow in FIG. Furthermore, during winter heating operation, if the hot air is not sufficiently high temperature at the beginning of operation, the coil spring 17 is in a compressed state as shown in Fig. 2, and the air is blown upward, but the hot air remains at a constant temperature (45 ~60°C), and when the coil spring 17 is heated and reaches the transformation temperature (approximately 30°C) or higher, it stretches as shown in Fig. 3, and the variable blade 9 tilts forward and downward.
The warm air is blown downward as indicated by the broken line arrow shown in FIG. On the other hand, as described above, the transformation temperature of the SMA coil spring 17 changes when the composition ratio of the constituent elements constituting the alloy or the memory treatment temperature for memorizing a predetermined shape changes slightly. However, the said
The relationship between temperature and displacement of the SMA coil spring 17 changes as shown in FIG. 5 depending on the magnitude of the load. That is, as the load increases (the magnitude of the load (a ₁ <b ₁ <c ₁ )) the temperature at which the coil spring 17 begins to expand increases to T _a , T _b , and T _c .
When the load becomes large (a ₁ <b ₁ <c _{1 )} , the amount of displacement (elongation) at the same temperature (for example, T ₁ in the figure) becomes small (a ₂ >b ₂ >c _{2 )} . Therefore, the provided SMA coil spring 1
Even if the transformation temperature in step 7 is slightly different from the desired temperature (approximately 30°C), the weight 12 can be moved to the balance rod 1.
0 and adjust the distance from the rotating shaft 9' of the variable blade to change the load applied to the SMA coil spring 17, so it can be adjusted so that the coil spring 17 stretches at a desired temperature. It becomes possible. Here, in the automatic wind direction switching device using the weight of the present invention and the device using the conventional bias coil spring h, the desired displacement at a predetermined temperature T is achieved by using an SMA coil spring having the same transformation point. Amount Δl
Which of the following can be achieved with a smaller spring will be explained using FIG. 9 mentioned above. 9th
The figure shows the relationship between displacement and generated force of an SMA coil spring at a given temperature. As mentioned above, in the conventional specification using the coil spring h, in order to obtain the desired displacement Δl, it is necessary to show the behavior of the straight line a _O.
SMA spring was required. However, in the automatic wind direction switching device of the present invention, if the weight is fixed at a predetermined position, the load applied to the SMA coil spring remains constant as shown by the straight line b′ _O in the figure.
In order to obtain the predetermined displacement Δl, create a curve that produces a generated force that exactly balances the load by the weight at the intersection Q.
An SMA coil spring is given that exhibits the behavior shown by a′ _O. The SMA coil spring shown by curve a′ _O has a smaller generated force than the SMA coil spring shown by curve a _O (however, the generated force F′ _O when restrained with displacement Δl=O is calculated from Fig. 9. As is clear, the spring is larger than the weight of the weight f _O ). In other words, the specification of this embodiment has a smaller SMA than the specification of the conventional example.
A manufactured coil spring would be a good thing. Therefore, if the number of turns and coil diameter are the same, the wire diameter can be made smaller and the cost of using expensive SMA can be reduced. is available at a much lower cost than before. Furthermore, as described above, the structure is simple as a method for controlling variations in the transformation point, which is a problem with SMA. Next, another embodiment will be described using FIG. 6. Since FIG. 6 corresponds to the above-mentioned FIG. 2,
Identical parts will be given the same numbers and explanations will be omitted. 21
is a shape memory alloy coil spring with a transformation temperature (approximately 30
It is a spring treated with memory so that it contracts when the temperature exceeds 10.degree. C.), and 22 is a stopper. Below the transformation temperature (approximately 30°C), as mentioned above, the material strength of the coil spring 21 is weak, so the coil spring 21 expands due to the load of the weight 12 and is held at a constant length by the stopper 22. The variable blades 9 are oriented upward, and as a result, air is blown upward during cooling operation. Further, during heating operation, when the coil spring 21 reaches a temperature higher than its transformation temperature, it generates a large force, overcomes the load of the weight 12, and contracts as shown by the arrow in the figure. As a result, the variable blades 9 are directed downward and hot air is blown downward. Here, in this embodiment as well, the load applied to the shape memory alloy coil spring 21 can be changed by moving the weight 12 back and forth with respect to the balance rod 10. Therefore, even if there are variations in the transformation temperature of the provided coil spring 21 made of shape memory alloy, it is possible to adjust the coil spring 21 so that it contracts at a desired temperature. Effects of the Invention As is clear from the above description, the automatic wind direction switching device for an air conditioner/heater of the present invention has a variable blade that changes the wind direction arranged in the air path of the air conditioner, and a balance rod protruding from one end of the variable blade. and a weight provided on the balance rod, and a weight that is provided so as to act on the balance rod between the rotary shaft of the variable blade and the weight, and is heated by warm air during heating operation to move the variable blade forward and downward. The shape-memory alloy coil spring deforms so as to be tilted, and the distance from the rotary axis of the variable blade to the balance rod can be adjusted with respect to the weight, so the shape-memory alloy coil spring This load can be easily changed, and as a result, even if the transformation temperature of the provided shape memory alloy coil spring varies, it expands and contracts at a desired temperature, and the angle of the variable blade can be changed. When a bias spring is used as in the conventional example, as described above, as the SMA coil spring is displaced, the spring force of the opposing bias spring increases, so a large generated force can be obtained. However, since the present invention uses a weight, a constant load is constantly applied to the SMA coil spring, so it is necessary to design an SMA coil spring that is smaller than when using a conventional bias spring. I can do it. Therefore, it is possible to provide an automatic wind direction switching device that is simpler in structure, has excellent temperature accuracy, and is less expensive than the conventional one.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an air conditioner equipped with an automatic wind direction switching device according to an embodiment of the present invention, FIGS. 2 and 3 are side views showing the operation of the variable blades of the same device, and FIG. FIG. 5 is a characteristic diagram of a shape memory alloy coil spring, FIG. 6 is a side view of another embodiment corresponding to FIG. 2, and FIG. 7 is a conventional automatic wind direction switch. A side view of the device, FIG. 8 is an enlarged plan view of the circle B in FIG. 7, and FIG. 9 is a characteristic diagram showing a comparison between a conventional shape memory alloy coil spring and an example. 9... Variable blade, 9'... Rotating shaft, 10... Balance shaft, 12... Weight, 17... Shape memory alloy (SMA) coil spring.

Claims (1)

[Claims] 1. A variable blade that changes the wind direction arranged in the air path of the air conditioner, a balance rod protruding from one end of the variable blade, a weight provided on the balance rod, and a space between the rotating shaft of the variable blade and the weight. a coil spring made of a shape memory alloy, which is provided so as to act on the balance rod, and is heated by hot air during heating operation to deform the variable blade so as to tilt the variable blade forward and downward; An automatic wind direction switching device for an air-conditioning/heating machine, wherein the distance from the rotation axis of the variable blade can be adjusted.