JPH01303385A - Damper opening/closing device - Google Patents

Abstract

PURPOSE:To obtain the title device having an earlier responsive speed and high reliability in opening/closing operation by heating a shape memory alloy made coil spring by heater for driving. CONSTITUTION:An opening/closing plate 102 for opening/closing an opening part 108 is energized by a leaf spring 110 in the opening direction. On the back side of the opening/closing plate 102, there are provided a shape memory alloy made coil spring 103 which coils around a heater 111, drive pin and slant cam 122. Based on a signal from a temperature sensor or the like, the heater is heated and the coil spring 103 is extended. The extension is converted into the rotating motion of the slant cam 122 through the drive pin. The rotating motion is transmitted to the opening/closing plate 102 through a spindle 128, thereby opening the opening part 108.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a damper opening/closing device for adjusting the flow rate of cold air in a refrigerating compartment or a switching compartment of an electric refrigerator or the like.

2. Description of the Related Art For example, in a refrigerator having a divided freezer compartment and refrigerator compartment, temperature control is performed by opening and closing a damper provided in a passage connecting the freezer compartment and the refrigerator compartment.

Conventionally, gas thermostatic bellows have been used as the drive source for opening and closing, but gas thermostatic bellows has problems such as slow response speed and increased device size.
Recently, drive sources using shape memory alloy coil springs have come into use. A conventional damper opening/closing device using a shape memory alloy coil spring as a drive source will be described below.

Conventional damper opening/closing devices are, for example,
There is one described in Publication No. 81.

This will be explained using FIGS. 4 to 6. FIG. 4 shows a sectional view of a conventional damper opening/closing device.

1 is a damper opening/closing device; 2 is a substrate of the damper device; an opening 3 is formed at one end thereof; and a support plate 4 is protruded from the upper surface of the midsection thereof. Reference numeral 6 designates an operating plate rotatably supported by the support plate 4, and an opening/closing plate 6 for opening and closing the opening 3 of the substrate 2 is attached to the tip end thereof.

Further, a bias spring 7 is attached to the actuating plate 6, which always biases the opening 3 in a direction to close it. 8 is a coil spring made of a heat-treated shape memory alloy so that it contracts when heated to a predetermined temperature or higher, and is attached to one end of the operating plate 6 on the side where the opening/closing plate 6 is not provided;
Normally, it is in an extended state and urges the actuating plate 6 in the direction of closing together with the urging force of the bias spring 7, and when it is contracted, the lower actuating plate 6 resists the urging force of the bias spring 7. It is biased in the direction of opening. Reference numeral 9 denotes a heater consisting of a positive temperature coefficient thermistor disposed within the hollow portion of the coil spring 8, and is connected in series to the coil spring 7s, so that the heater 9 is energized when the damper is commanded to open. It has become. When the heater 9 is energized, the coil springs 8 near the heater 9 begin to contract in order, and as a result, the contraction force of the coil springs 8 overcomes the biasing force of the bias spring 7, causing the actuating plate 6 to move clockwise. , that is, it is rotated in the opening direction. Note that 1o indicates a storage portion in which the coil spring 8 and heater 9 are stored.

The operation of the damper opening/closing device configured as described above will be explained below.

First, under normal conditions, that is, when there is no command to open the damper, the heater 9 is not energized, the coil spring 8 is in an extended state, and the actuating plate 6 is biased in the closing direction by the biasing force of the bias spring 7. Therefore, the opening 3 is closed by the opening/closing plate 6 of the actuating plate 6.

When a command to open the damper is issued from a control circuit (not shown), the relay switch 11 is closed, current flows through the series circuit of the heater 9 and the coil spring 8, and the coil spring 8 is heated by the heater 9. Ru. Therefore, the coil spring 8 contracts, and the actuating plate 6 is rotated clockwise against the biasing force of the bias spring 7, thereby opening the opening 3.

Problems to be Solved by the Invention However, in the above conventional configuration, the damper opening/closing device 1
When installed in a refrigerator, the temperature of the main body on which the coil spring 8 is placed will be at least around 0°C due to the cold air, and at its coldest it may be around -30°C. Assuming the above situation, the lower limit of the transformation temperature of the coil spring 8 is usually designed to be 0°C or less, and in that case, the upper limit of the transformation temperature will be around 60°C. Therefore, since a positive temperature coefficient thermistor is used for the heater 9 that heats the coil spring 8, the response speed in the direction of opening the opening 3 is fast, but as shown in Fig. 6, the temperature of the heater 9 is around 270°C. Conversely, when the temperature inside the refrigerator becomes low and a damper closing command is issued from the control circuit, the temperature of the coil spring 8 decreases to about o.
℃, the lower limit of transformation temperature will not be reached and the opening 3 will not be closed, and the temperature of the coil spring 8 will change from about 270℃ to 0.
It takes a considerable amount of time to reach ℃, and during that time, cold air flows into the inside of the refrigerator, causing the problem that the inside of the refrigerator becomes too cold. In other words, what the customer needs is a response speed for closing the aperture 3 rather than a response speed for opening it, so there is a problem that the customer's needs are not met in this respect.

In addition, since the upper limit of the transformation temperature of the coil spring 8 is raised from about 60 degrees Celsius to around 270 degrees Celsius, the expansion and contraction life of the coil spring 8, which is close to the heat treatment temperature, deteriorates and the shape memory effect disappears, making it impossible to operate. there is a possibility.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a damper opening/closing device that has a fast response speed for opening and closing an opening and has high reliability in opening and closing operations.

Means for Solving the Problems In order to achieve the above object, a damper opening/closing device of the present invention includes a substrate having an opening, an opening/closing plate for opening and closing the opening, and a plate for biasing the opening/closing plate in a closing direction. a shape memory alloy coil spring in which a heater is coiled as a drive source attached to the back side of the opening/closing plate; a bias spring provided via a driver in a direction to suppress the output of the shape memory alloy coil spring; A drive pin is fitted to the drive body via a compression spring, and a drive cam is provided that rotates or idles due to the reciprocating motion of the drive body, and one end contacts an inclined protrusion formed on an inclined cam that rotates at the same time as the drive cam. death,
A spindle is provided, the other end of which is in contact with the opening/closing plate.

Effect: According to this configuration, the shape memory alloy coil spring is expanded by the heat generated by the coiled heater to move the drive body, rotate the drive cam via the drive pin, and open the opening with the inclined cam provided on the drive cam. Cultivate. Also, when the heater power is turned off, the drive pin does not rotate the drive cam due to the force of the bias spring and returns to its original position simultaneously with the drive body while compressing the compression spring, so the opening remains open.
Next, the shape memory alloy coil spring expands due to the heat generated by the heater, moves the drive body, rotates the drive cam via the drive pin, and closes the opening with the inclined cam provided on the drive cam.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, 101 is a damper opening/closing device, which includes an opening/closing plate 1o2 as a driven member, a shape memory alloy coil spring 103 as its driving source, and a cover 104 for protecting the driving source from cold air. It is provided on the back side of the substrate 106. The opening/closing plate 102 is supported by shafts 106 provided on both sides of the lower part so as to be openable and closable by bearings 107 of a base plate 105, and a slightly larger gasket 109 is placed at a position corresponding to the opening 10B provided on the base plate 106. The opening bottom portion 108 is always biased in the closing direction by a leaf spring 110 fixed to the housing base plate 106. Inside the cover 104 that protects the drive source from cold air, a heater 111 is coiled and telescopically attached to a shape memory alloy coil spring 103, and a drive body 112 is attached to one end of the shape memory alloy coil spring 103. A bias spring 113 is attached to the other end of the drive body 112 in a direction that suppresses the output of the shape memory alloy coil spring 103. A compression spring 114 is attached to the inside of the driving body 112, and a driving pin 115 that operates in the compression direction of the compression spring 114 is incorporated. A drive cam 118 having a gear part 116 and a latch part 117 is rotatably attached to the tip of the drive pin 116 around a drive shaft 119, and one end of the latch part 117 is fixed to a latch lever 120 by a push spring 121. It is biased counterclockwise. An inclined cam 122 that fits into the gear portion 116 of the drive cam 118 is attached to the left side of the drive cam 118, and a protrusion 123 having a cam shape is formed on the back side of the inclined cam 122.
4, and the lever 124 is attached so that the rotation of the inclined cam 122 turns the fixed contact 126 and the movable contact 128 ON or OFF. Further, an inclined protrusion 127 is formed on the front side of the inclined cam 122 so that the spindle 12
8, and the other end is in contact with the opening/closing plate 102.

The operation of the damper opening/closing device configured as described above will be explained below.

When the temperature inside the refrigerator rises while the opening/closing plate 102 closes the opening 108, the control circuit 129 energizes the heater 111 according to the signal from the temperature sensor 130 to heat it.
The heat causes the shape memory alloy coil spring 103 to move linearly, overcomes the force of the bias spring 113, and drives the drive body 1.
12 is moved until it abuts against the stopper 131. Simultaneously with the movement of the drive body 112, the tip end 132 of the drive pin 115 comes into contact with the latch part 117 of the drive cam 118, causing it to rotate 90 degrees counterclockwise about the drive shaft 119. At the same time, the tilting cam 122 rotates 180 degrees to reach the maximum tilt dimension, opening the opening/closing plate 102 via the spindle 128. At this time, the lever 124 pushes up the movable contact 126 to turn off the switch circuit, and the timer controls the
The power supply to the heater 111 is automatically cut off in about 3 seconds.

When the heater is de-energized, the shape memory alloy coil spring 103 loses its output depending on the ambient temperature (approximately 0° C.), and tries to return to its original state by the force of the bias spring 113. At this time, since the drive cam 118 is fitted with the latch lever 120, it does not rotate, but the drive pin 115 compresses the compression spring 114 attached to the drive body 112, and returns to the original position. That is, when the fixed contact 126 and the movable contact 126, which are switch circuits, are OFF L, the opening/closing plate 102 is in the open state and the position is detected. On the other hand, when the temperature of the refrigerator becomes low, the heater 111 is energized and heated in response to the signal from the temperature sensor 130, and the heat directly moves the shape memory alloy coil spring 103, overcoming the force of the bias spring 113 and moving the driver 112 to the stopper 131. Move it until it touches the. Simultaneously with the movement of the drive body 112, the tip end 132 of the drive bin 115 comes into contact with the latch part 117 of the first drive cam 118 and rotates 90' counterclockwise about the drive shaft 119. At the same time, the tilt cam 122 rotates 180°.
Then, the inclination dimension becomes the minimum, and the opening/closing plate 102 is brought into a fully closed state via the spindle 128. At this time, lever 12
4 is a movable contact, 126 and a separate switch circuit are turned on, and power to the heater 111 is automatically cut off in about 2 to 3 seconds under timer control. When the heater is de-energized, the shape memory alloy coil spring 103 loses its output depending on the ambient temperature (approximately 0° C.) and tries to return to its original state by the force of the bias spring 113. At this time, the drive cam 118 is
20, the drive pin 115 does not rotate and returns to its original position by compressing the compression spring 114 attached to the drive body 112.

As described above, according to this embodiment, the substrate 106 having the opening 10B, the opening/closing plate 102 that opens and closes the opening 108, and the leaf spring 110 urging the opening/closing plate 102 in the closing direction,
A shape memory alloy coil spring 103 coiled with a heater 111 as a drive source attached to the back side of the opening/closing plate 102, and a bias spring 113 provided via a driver 112 in a direction to suppress the output of the shape memory alloy coil spring 103. A drive bin 115 is fitted to the drive body 112 via a compression spring 114, and a drive cam 118 is provided which rotates or idles due to the reciprocating motion of the drive body 112.
By providing a spindle 128 whose one end contacts an inclined protrusion 127 formed on an inclined cam 122 that rotates at the same time as the drive cam 118, and whose other end contacts the opening/closing plate 102, when the heater 111 is energized. The opening/closing plate 102 is
The response speed is fast in both the opening and closing directions, providing performance that meets customer needs.

Effects of the Invention As described above, the present invention includes a substrate having an opening, an opening/closing plate for opening and closing the opening, a leaf spring for biasing the opening/closing plate in the closing direction, and a drive attached to the back side of the opening/closing plate. A shape memory alloy coil spring coiled with a heater as a source, a bias spring provided via a drive body in a direction to suppress the output of the shape memory alloy coil spring, and a drive bottle fitted to the drive body via a compression spring. A spindle is provided with a drive cam that rotates or idles due to the reciprocating motion of a drive body, one end of which contacts an inclined protrusion formed on an inclined cam that rotates at the same time as the drive cam, and the other end of which contacts the opening/closing plate. By providing this, when the heater is energized, the shape memory alloy coil spring effectively receives the heat of the coiled heater.The shape memory alloy coil spring has a fast elongation speed, and is responsive in both the opening and closing directions. improves. In addition, since the heater power is cut off approximately 2 to 3 seconds after the switch circuit operates, the temperature of the shape memory alloy coil spring does not rise much and remains around 80℃, so it has a long expansion and contraction life and is highly reliable. A damper opening/closing device can be constructed, and its practical effects are impressive.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a damper switching device according to an embodiment of the present invention, Fig. 2 is a sectional view taken along line AA of the same switching device, Fig. 3 is a control block diagram of the same switching device, and Fig. 4 is a conventional damper switching device. FIG. 5 is a control block diagram of the damper opening/closing device, and FIG. 6 is a rise characteristic diagram of the positive temperature coefficient thermistor of the same switching device. 101... Damper opening/closing device, 102...
... Opening/closing plate, 103... Shape memory alloy coil spring, 106... Substrate, 108... Opening, 110... Leaf spring, 111... ...Heater, 112...Driver, 113...
Bias spring, 114... Compression spring, 116.
... Drive pin, 118 ... Drive cam, 1
22... Inclined cam, 127... Protrusion,
128...Spindle. Name of agent: Patent attorney Toshio Nakao and 1 other person ro
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Claims (1)

[Claims] A shape memory coiled substrate having an opening, an opening/closing plate for opening and closing the opening, a leaf spring for biasing the opening/closing plate in the closing direction, and a coiled heater as a driving source attached to the back side of the opening/closing plate. An alloy coil spring, a bias spring provided with a drive body attached in a direction to suppress the output of the shape memory alloy coil spring, and a drive pin fitted to the drive body via a compression spring, and the reciprocating movement of the drive body A damper comprising a drive cam that rotates or idles, and a spindle that has one end in contact with an inclined protrusion formed on the inclined cam that rotates at the same time as the drive cam, and the other end in contact with the opening/closing plate. Switchgear.