JPS6127441A - Air flow path change-over device - Google Patents

Abstract

PURPOSE:To make it possible to carry out the air flow changeover smoothly without any erroneous operation in an extremely simple sequence by temporary opening and closing of the contact of a switch and temperary stopping of heating manner. CONSTITUTION:In the case of switching from a hot air path 3b to a hot air path 3a by a signal from air path changeover instructing means 14, blasting means 1 remains to be actuated and heating means 2 is not actuated for a certain period of time, thus blasting cool air toward s shape memory alloy. Then, the shape memory alloy is forcibly elongated by a restoring force exerted by a return spring 6, and changeover to the hot air path 3a is performed more rapidly than in the case of a convertional changeover device. Thereafter, when the heating means 2 is again actuated, hor air flows through the hot air path 3a. By this arrangement, even a simple control sequence of the control means can switch the hot air path, and mutual changeover of two hot air paths is immediately carried out. Hence, the air flow path changeover device and the opening and closing mechanism of the damper can be made smoothly and compactly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air passage switching device that switches between a plurality of air passages using a damper.

Structure of conventional example and its problems Conventionally, this type of air path switching device has, as shown in FIGS. 1 and 2, air blowing means 1, heating means 2, air blowing paths 3a, 3b,
It is composed of a damper 4 for switching between the plurality of air passages 3a and 3b, a solenoid 5 for driving the damper 4, a return spring 6, and a control means 7. Figure 1 shows the ventilation path 3a.
On the other hand, FIG. 2 shows a state in which air can be blown to the air passage 3b.

The above configuration has the disadvantage that the air path switching device becomes large because a solenoid is used to drive the damper.

Figures 3 and 4 are diagrams showing the structure of the main body of the damper 4 that uses the shape memory alloy 8 to drive the damper 4.

FIG. 5 is a control circuit diagram, which includes a terminal 9 for passing current through the shape memory alloy 8, a relay contact (switch) 10 (normally closed) forming a parallel circuit with the shape memory alloy, an AC power supply 11, and a bidirectional The third group is element group 12 and transistor group 13.
, an air path switching command means 14. FIG. 6 is a control sequence diagram of a conventional example.

In the configuration described above, in order to switch the air path from the state shown in FIG. 3 to the state shown in FIG. The driving point temperature of the shape memory alloy 8 must be created by self-heating (the resistance of the shape memory alloy is only a few Ω). This is because in the hot air path 3a, the shape memory alloy 8
This is because the driving point temperature cannot be created because hot air does not reach the area.

Therefore, without creating a special power supply circuit to flow 4A, the shape memory alloy 8 and the relay contact (switch) 10 are configured in a parallel circuit, and the parallel circuit and the heating means 2 are configured in a series circuit, Relay contact (switch) 10f: If the wattage of the heating means is 400W, for example, 4A of current will flow through the shape memory alloy 8 to reach the driving point temperature and generate a contraction force. . (6th
(FIG. 15) Therefore, the damper 4 forms a hot air path 3b against the restoring force of the return spring 6. After the hot air path 3b is formed, even if the contact (switch) 10 of the relay is closed and no current flows to the shape memory alloy 8, the temperature of the hot air by the blowing means 1 and the heating means 2 will change the shape. The shrinkage force of the memory alloy 8 is self-retained, and the hot air path 3b continues to be formed.

Next, when switching from the hot air path 3b in FIG. 4 to the hot air path 3a in FIG. Stop. (FIG. 6, 16) Then, the shape memory alloy 8 is no longer able to hold itself, and the restoring force of the return spring 6 forms the hot air path 3a. Thereafter, the control means 7 energizes the blower means 1 and the heating means 2 again, and warm air is blown into the hot air path 3a. However, in the above configuration, temporarily the blower fan 1,
When the damper 4 is activated by the return spring 6 while the heating means 2 is stopped, and the control means 7 energizes the hot air means 1 and the heating means 2 before the hot air path 3b is completely closed, the shape memory alloy The warm air hits 8, and due to the shrinkage force, the warm air path 3
A problem arose in that the hot air path 3b was formed instead of the hot air path 3b.

In addition, the time management for temporarily stopping the blowing means 1 and the heating means 2 and creating the hot air path 3a is affected by the ambient temperature around the shape memory alloy 8, and the time required to switch the air path is long. However, stopping the blower means 1 and the heating means 2 sufficiently to prevent malfunctions gives rise to the problem of giving the user a feeling of anxiety that something is wrong.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a device which solves the above-mentioned conventional problems and allows smooth air path switching without malfunctions and with an extremely simple control sequence.

Structure of the Invention In order to achieve this object, the present invention includes a blowing means, a heating means, two hot air paths provided downstream of the heating means, and a damper for switching between the two hot air paths. , a shape memory alloy provided in one of the two hot air paths and provided at one end of the damper, a switch for passing a current to create a driving point temperature of the shape memory alloy, and a switch for supplying a current to create a driving point temperature of the shape memory alloy; The shape memory alloy and the switch are composed of a parallel circuit, the parallel circuit and the heating means are composed of a series circuit, and the control means In response to the air path switching command signal, the contacts of the switch are opened for a certain period of time, a current is passed through the shape memory alloy, the damper is driven, the hot air path is switched, and the hot air path is switched. The shape memory alloy is self-supported by hot air, and the heating means is not energized for a certain period of time according to a signal from the air path switching command means, and the air blowing means is kept energized and cold air is blown onto the shape memory alloy. After turning on the hot air passage and driving the damper to switch the switched hot air passage again to the hot air passage without the shape memory alloy, the heating means is energized to blow hot air.

This configuration allows the temporary opening and closing of the switch contacts and
The hot air path can be switched simply by temporarily stopping the heating means.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to the main body configuration diagrams shown in FIGS. 3 and 4, the control circuit diagram shown in FIG. 5, and the control sequence diagram shown in FIG. 7.

The difference from the conventional example is that the signal from the air path switching command means 14 shown in FIG. 5 causes the hot air path 3b in FIG.
When switching to , the blowing means 1 blows cold air onto the shape memory alloy until it is energized, without energizing the heating means 2 for a certain period of time. (FIG. 7) Then, the shape memory alloy cannot memorize and retain its shape, is forcibly expanded by the restoring force of the return spring 6, and switches to the hot air path 3a of FIG. 3 much more quickly than in the conventional example. Thereafter, when the heating means 2 is energized again, the hot air flows through the hot air path 3a. Note that the switching of the air path from the hot air path 3a to the hot air path 3b in FIG. 3 is the same as in the conventional example, and will therefore be omitted.

Further, in FIG. 5, a relay contact is used as a switch for passing current through the shape memory alloy, but a semiconductor switch may also be used, and the present invention is not limited to the above embodiment.

Effects of the Invention According to the present invention, a blower means, a heating means, a damper for switching between two hot air paths, a shape memory alloy for driving the damper, a switch for passing current through the shape memory alloy, and a switch are provided. It consists of a control means for controlling the flow rate and an air path switching command means,
The shape memory alloy and the switch are configured in a parallel circuit, and this parallel circuit and the heating means are configured in a series circuit, so cold air is blown onto the shape memory alloy while each of these stages is energized9. Since the damper is driven by the control means, the hot air path can be switched with a simple control sequence of the control means, and the mutual switching between the two hot air paths is instantaneously performed. The opening/closing mechanism can be made smooth and compact. Furthermore, since the two hot air paths can be switched quickly, there is no malfunction due to a mistake in switching between the hot air paths, so the user does not feel uneasy.

In addition, since the shape memory alloy is located in the hot air path after the damper is switched, it is configured so that the shape memory alloy only needs to be energized for a limited time, which prevents deterioration of the shape memory alloy and increases reliability. The better the performance, the more effective it will be.

[Brief explanation of the drawing]

Figures 1 and 2 are main part configuration diagrams of a conventional air path switching device.
3 and 4 are main part configuration diagrams of the air path switching device of another conventional example and an embodiment of the present invention, FIG. 5 is a circuit diagram of the same control circuit, and FIG. 6 is a conventional control sequence diagram. , FIG. 7 is a control sequence diagram of an air path switching device according to an embodiment of the present invention. 1... Air blowing means, 2... Heating means, 3a, 3b...
・Temperature 10° air path, 4... Damper, 7... Control means, 8... Shape memory alloy, 10... Switch (relay), 14...
Air path switching command means, 15... A part of the flow which opens the switch for a certain time, 17... A part of the flow which does not energize the heating means for a certain time. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] a blowing means, a heating means, a pair of hot air passages provided downstream of the heating means, a damper for switching between the pair of hot air passages, and a damper provided on one of the pair of hot air passages. It is comprised of a shape memory alloy provided at one end, a switch for causing a current to flow through the shape memory alloy for driving the shape memory alloy, a control means for energizing the switch, and an air path switching command means; The shape memory alloy and the switch are constituted by a parallel circuit, the parallel circuit and the heating means are constituted by a series circuit, and the control means controls the contacts of the switch for a certain period of time by a signal from the air path switching command means. , the shape memory alloy is opened, a current is applied to the shape memory alloy, the damper is driven, and the hot air path is switched, and then the shape memory alloy provided in one of the hot air paths is self-supported by the hot air. Based on the configuration and the signal from the air path switching command means, the heating means blows cold air onto the shape memory alloy while keeping the air blowing means energized without energizing it for a certain period of time to drive the damper and switch the air path. The air path switching device is configured to switch the heated air path again to the hot air path without the shape memory alloy, and then energize the heating means to blow hot air.