JPH0715346B2 - Damper opening and closing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper opening / closing device in which a driven-side opening / closing plate is operated by a drive element made of a shape memory alloy.

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

Conventionally, a gas thermo bellows has been used as a drive source for opening / closing the gas thermo bellows.However, the gas thermo bellows has a problem that the response speed is slow and the device becomes large. The one using the driving element has been used.

A conventional damper opening / closing device using a drive element made of a shape memory alloy as a drive source will be described below.

A conventional damper opening / closing device is disclosed in, for example, Japanese Utility Model Laid-Open No. 62-167043. FIG. 6 is a sectional view of a conventional damper opening / closing device.

In the conventional damper opening / closing device 1, an opening 3 is formed at one end of a base plate 2 of the damper device, and a support plate 4 is projectingly provided on the upper surface of the middle abdomen thereof.

An opening / closing plate 5 is rotatably supported by the support plate 4, and a packing 6 for opening / closing the opening 3 of the substrate 2 is attached to the tip of the opening / closing plate. Further, a leaf spring 7 is attached to the opening / closing plate 5 so as to constantly bias the opening 3 in a direction of closing the opening 3.

Reference numeral 8 is a drive element made of a shape memory alloy that is heat-treated so as to shrink when heated to a predetermined temperature or higher, and is attached to one end of the opening / closing plate 5 on the side where the packing 6 is not provided. When it contracts, it opens and closes the opening / closing plate 5, and when it contracts, it opens the opening / closing plate 5 against the biasing force of the plate spring 7. It is designed to bias in the direction.

Reference numeral 9 denotes a heater composed of a positive temperature coefficient thermistor disposed in the hollow portion of the driving element 8 and has terminals 1 (9 ') and 2
It is connected to an external power source through (9 ″), is connected in series to the drive element 8, and is energized to the heater 9 when a damper opening command is issued. Then, contraction starts in order from the drive element 8 near the heater 9, and as a result, the contraction force of the drive element 8 exceeds the biasing force of the leaf spring 7 and the operating plate opening / closing plate rotates clockwise, that is, in the opening direction. Be moved.

Reference numeral 10 denotes a cover for housing the driving element 8 and the heater 9. FIG. 7 is a control block diagram used in a conventional damper opening / closing device.

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

First, in a normal state, that is, when the opening command of the damper is not issued, the heater 9 is not energized, so that the drive element 8 is in the extended state and the opening / closing plate 5 is biased in the closing direction by the biasing force of the leaf spring 7. Therefore, the opening 3 is closed by the plate 6 of the opening / closing plate 5.

Then, when a command to open the damper is issued from a control circuit (not shown), the relay switch 11 is closed and a current flows through the series circuit of the heater 9 and the drive element 8, and the drive element 8 is heated by the heater 9. It For this reason, the drive element 8 contracts and the opening / closing plate 5 is rotated clockwise against the biasing force of the leaf spring 7 to open the opening 3.

SUMMARY OF THE INVENTION However, in the above configuration, the shape memory alloy spring (driving element) is unstable in holding, and the connection between the driving element and the opening / closing plate and the attachment of the leaf spring are complicated, which requires a lot of man-hours. There was a point.

Further, the leaf spring urges the open / close plate in the closing direction, but if a certain holding force is given to improve the sealing performance, it will become a considerably large force when the open / close plate is fully opened, increasing the output on the drive element side. Therefore, it is necessary to increase the size of the shape memory alloy spring.

In addition, heat conduction from the heater for heating the driving element is difficult to be transmitted to the driving element, resulting in lack of responsiveness and lack of reliability and assembling of the lead wire connection processing method.

INDUSTRIAL APPLICABILITY The present invention is a damper opening / closing device that is inexpensive and easy to assemble, and securely holds a shape memory alloy spring (driving element), a damper opening / closing device that opens and closes an opening / closing plate with a small shape memory alloy, and heating of the shape memory alloy. The present invention aims to provide a damper opening / closing device with improved reliability and assembly of lead wires for use.

Means for Solving the Problems In order to solve the above problems, the present invention rotatably supports an opening / closing plate that opens and closes an opening communicating with a cold airflow inlet with a second bearing of a second opening of a substrate, Two legs are provided between the shafts, a bias spring is attached to the one leg, and a shape memory alloy spring is attached to the other leg, and the bearing side of the second opening is fixed to the fixing plate that covers the opposite opening surface. The other end of the bias spring and the shape memory alloy spring is attached, and a rib for holding the two springs at an angle is provided on the fixed plate.

Further, the bias spring is a coil spring, which has an initial tension and a small spring constant.

Further, the shape memory alloy spring is a coil spring, a heater wire is wound around the wire material of the spring, and the heater wire and the lead wire are connected via a crimp terminal.

Action Due to the above configuration, since the shape memory alloy spring and the bias spring are held at a certain angle on the fixing plate, the other ends of the two legs of the opening / closing plate can be easily attached and easily assembled.

In addition, the bias spring closes the opening / closing plate without leaking cold air by the initial tension, and can be opened by the power of the relatively small shape memory alloy.

Further, the heater wire wound around the shape memory alloy is securely attached to the lead wire.

Embodiment An embodiment of claim (1) of the present invention will be described in detail with reference to FIG. 1, FIG. 2 and FIG. Reference numeral 20 denotes a substrate which is attached to a cold air outlet of a refrigerator or the like and has a first opening portion 21 through which cold air flows. The substrate 20 has a protrusion 24 having a U-shaped bearing 23 for rotatably supporting the rotary shaft 22a of the opening / closing plate 22, a shape memory alloy spring 25 as a drive source, and a bias spring.
A second opening 27 for storing 26 is provided. The opening / closing plate 22 has an opening / closing portion 22b to which a sealing material 28 for opening / closing the first opening 21 of the substrate 20 and sealing the first opening 21 is attached, and the shape memory alloy spring. 25,
There is a shank 22e having two legs A, B (22c, 22d) holding a bias spring 26. The substrate 20 is provided at both ends of the shaft portion 22e.
A rotary shaft 22 that rotatably engages with a U-shaped bearing portion 24 of
a is provided. 29 is a cover, tapping screw 30
It is attached to the substrate 20 by and regulates the vertical position of the opening / closing plate 22. Shape memory alloy spring 25 that is the driving source
A heater wire 31 having an insulating coating for heating the shape memory alloy spring 25 to produce a shape memory effect is wound around the two ends, and two or more holes 32a through which the shape memory alloy spring 25 is passed and hook portions are provided at both ends. A holder A32 having 32b and a holder B33 having two or more holes 33a through which the shape memory alloy spring 25 is inserted and a hole 33b through which a tapping screw 35 for attaching to the fixing plate 34 is also attached. The heater wire 31 is connected to an external power source through a terminal wire 36 by a lead wire 37. The bias spring 26 has a hook portion 26a at one end and an opening / closing plate 22.
The other leg B22d is stretched by holding the hook portion 26a at the other end in a hole 34a provided in the fixing plate 34.

In the first aspect, the fixing plate 34 has a claw portion 38a at the tip thereof.
Ribs A38 and B39 having a rib A38 are provided.
Is located adjacent to the foot A22c of the opening / closing plate 22, and the rib B39 is located adjacent to the foot B22d of the opening / closing plate 2.
A38 and B39 are provided at positions that do not come into contact with each other even when the opening / closing plate 22 is opened / closed.

In the above-described configuration, the shape memory alloy spring 25 and the bias spring 26 are assembled to the fixing plate 34.First, in the shape memory alloy spring 25, the heater wires 31 are wound in advance and the holders A32 and B33 are attached to both ends thereof. After fixing the holder B32 to the mounting hole 40 of the fixing plate 34 with the tapped screw 35, the holder A32 is held by the claw portion 38a of the rib A38 of the fixing plate 34 by extending the shape memory alloy spring 25.

Next, the bias spring 26 hooks the hook portion 26a at one end into the hole 34a provided in the fixed plate 34, and extends the bias spring 26 at the other end 26b, thereby extending the claw portion 3 of the rib B39 of the fixed plate 34.
Hold on to 9a. After that, the fixing plate 34 is fixed to the second opening 27 of the substrate 20 on the opposite side of the opening / closing plate 22 with the tapping screw 41. Next, the opening / closing plate 22 to which the sealing material 28 is attached in advance is attached to the U-shaped bearing portion 23 of the projecting portion 24 of the substrate 20 as a rotary shaft.
22a is installed so that it engages, and then the claw portion 38a of the rib a38
The holder A32 held by the open / close plate 22 foot A2 of the shaft 22a
The bias spring 26 held by the claw portion 39a of the rib B39 is transferred to the foot B22d of the shaft portion 22e of the opening / closing plate 22 at 2c. After that, the cover 29 is fixed to the substrate 20 with the tapping screw 30.

Next, the operation will be described. When the temperature inside the refrigerator is higher than the set value, the heater wire is controlled by the control circuit (not shown).
When electricity is applied to 31, the shape memory alloy spring 25 transforms from the martensite phase to the austenite phase and contracts, causing a bias spring.
The opening / closing plate 22 is moved in the opening direction through the holder A32 against the reaction force of 26, and is further held in the fully opened state.
Let cold air flow into the refrigerator from 21.

Conversely, when the temperature in the refrigerator becomes lower than the set value, the control circuit (not shown) stops the energization of the heater 31, the temperature of the shape memory alloy spring 25 decreases, and the austenite phase transforms to the mantensite phase. Output decreases. Open / close plate 22
Is again rotated in the closing direction by the force of the bias spring 26 to close the first opening 21 of the substrate 20 and stop the inflow of cold air into the refrigerator.

As described above, in the claim (1), the fixed plate is provided with the shape memory alloy spring and the two ribs for locking the bias spring, and the fixed plate is provided with the shape memory alloy spring and the bias spring. After attaching in advance to the board and installing the opening / closing plate, attach one end of the shape memory alloy spring and the bias spring locked to the ribs A, B of the fixed plate to the legs A, B of the opening / closing plate shaft. Relocate. Further, the cover is screwed and assembled, so that the assembly is easy.

The description of claim (2) of the present invention will be described in detail with reference to FIGS. 1, 2, and 4. The basic structure is the same as that of claim 1, and therefore omitted. The bias spring 26 stretched between the open / close plate 22 and the fixed plate 34 is a coil spring having an initial tension.

Next, the operation will be described. When the opening / closing plate 22 is closed, the total closing force of the opening / closing plate 22 is f ₁ −F ₁ as shown in FIG.
Determined by F ₁ is determined by the spring characteristics of the shape memory alloy spring in the martensite phase. In order to obtain the full closing force, the bias spring 26 must generate a force corresponding to the target full closing force. At this time, the force f ₁ of the bias spring 26 is equal to the initial tension (f ₀ )
+ (Expansion of bias spring 26 when fully closed x spring constant of bias spring 26 (K ₀ ), where f ₁
-F ₁ = and all closing force. Next, when the temperature inside the refrigerator becomes higher than the set value, the heater wire 31 is energized by an external control circuit (not shown), and the shape memory alloy spring 25 generates a force to shrink. This force is proportional to the temperature, but the extension (strain) of the spring from the normal temperature state is an inversely proportional force. When moving from fully closed to fully open by this force, the force f _{3 of the} bias spring, which is a force against the generated force F ₂ of the shape memory alloy spring 25, is between the opening / closing plate 22 and the first opening 21. Increases in proportion to changes in dimensions. To ensure full opening, f
₃ (f ₀ (initial tension) + f ₄ (spring constant x spring extension)) <F ₂
The relationship of (output of the shape memory alloy spring in the fully opened state) is necessary.

As described above, the initial tension of the bias spring is f ₀ ,
By setting the spring constant to K ₀ , the full opening force of F ₃ can be obtained at the time of full opening, and the full closing force can be set to F ₄ .

A description of claim (3) of the present invention will be given with reference to FIGS. 1, 2, and 4.

The basic structure is the same as in claim (1), and thus the description thereof is omitted. The shape memory alloy spring 25 is a coil spring and a heater wire 31.
Is wrapped around. Mating parts on both ends of the heater wire 31
A crimp terminal 42 having 42a is crimped. 43 is a crimping portion 43 fixed to the fixing plate 34 and crimping the lead wire 37 to one end.
It is a terminal receptacle having a protruding portion 43b that engages with the mating portion 42a of the crimp terminal 42 at a and the other end. The heater wire 31 and the lead wire 37 can be connected by press-fitting the mating portions 42a of the crimp terminals 42 at both ends of the heater wire 31 into the projecting portions 43b of the terminal receivers 43, and then soldering or the like is unnecessary. , Fixed plate
34 is attached to the substrate 20 with the tapping screw 41. At the time of use, even if a force is applied to the lead wire 37, a force is not applied to the heater wire because the terminal receiver 43 holding the lead wire 37 is fixed to the fixing plate 34.

Advantageous Effects of the Invention (1) In claim (1), a substrate having a first opening communicating with the cold airflow inlet and a second opening, and opening and closing the second opening, An opening / closing plate pivotally supported by a bearing provided in the second opening, opening and closing the second opening, and having two legs between the bearings of the second opening; and a second opening. Fixing plate for covering the opening surface on the side opposite to the bearing side, a bias spring having one end attached to the foot of the opening / closing plate and the other end attached to the fixing plate, and one end attached to the other foot of the opening / closing plate, The shape memory alloy spring, the end of which is attached to the fixed plate and which generates a force that opposes the bias spring, and the second opening portion on the bearing side of the substrate are covered, and the shaft portion of the opening / closing plate is rotatably held. The fixing plate has a cover, and a bias spring and a shape memory alloy spring are held on the fixing plate at a certain angle. By fixing one end of the shape memory alloy spring and the bias spring to the fixed plate in advance and holding the other end to the rib of the fixed plate, the fixed plate is fixed to the substrate, and then the open / close plate is installed. By attaching the shape memory alloy spring held by the ribs of the fixing plate and one end of the bias spring to the two legs of the opening / closing plate, respectively, it is possible to provide an inexpensive damper opening / closing device that can be easily assembled.

(2) Further, in claim (2), the bias spring is a coil spring, one end of which is fixed to the substrate and the other end of which is attached to the foot of the opening / closing plate, and the coil spring has an initial tension and is relatively small. By having a spring constant, the full closing force can be secured and the drag force at the time of full opening can be reduced, so the shape memory alloy spring can be made smaller and the overall size can be reduced, and an inexpensive damper opening / closing device can be provided. it can.

(3) Further, in claim (3), the shape memory alloy spring is a coil spring, and the shape memory alloy spring comprises:
A heater wire is wound around the wire, crimp terminals are crimped at both ends of the heater wire, and a terminal receiver that engages with the crimp terminal is attached to a lead wire that is connected to the power supply section. In addition, a fixing plate for fixing the lead wire is provided near the lead wire, the crimp terminal, and the terminal receiver, and by fixing the fixing plate to the substrate, the connection between the heater wire and the lead wire connected to the power supply side can be achieved. It is possible to provide a damper opening / closing device that is easy to perform, inexpensive, and robust without applying excessive force to the heater wire even if external force is applied to the lead wire.

[Brief description of drawings]

1 is an exploded perspective view of a damper opening / closing device of the present invention, FIG.
FIG. 3 is a cross-sectional view of the damper opening / closing device of the present invention, FIG. 3 is a cross-sectional view showing an assembling order of main parts of the damper opening / closing device of the present invention, and FIG. 4 is a shape memory alloy spring force and bias of the damper opening / closing device. 5 is a graph showing a relationship of spring force, FIG. 5 is an enlarged perspective view of an essential part of the damper opening / closing device, FIG. 6 is a sectional view of a conventional damper opening / closing device, and FIG. 7 is a control circuit diagram of the conventional damper opening / closing device. is there. 20 …… Substrate, 21 …… First opening, 22 …… Opening / closing plate, 22c,
22d …… foot, 23 …… bearing, 25 …… shape memory alloy spring, 2
6 …… Bias spring, 29 …… Cover, 31 …… Heater wire, 3
4 …… Fixing plate, 37 …… Lead wire, 38,39 …… Rib, 42 ……
Crimp terminal, 43 …… Terminal receiver.

Claims (3)

[Claims] 1. A substrate having a first opening and a second opening communicating with a cold air flow inlet, and opening and closing the first opening,
And is pivotally supported by a bearing provided in the second opening,
An opening / closing plate that opens and closes the first opening and has two legs between bearings of the second opening, and a fixing plate that covers an opening surface of the second opening opposite to the bearing side. , One end is attached to the foot of the opening and closing plate, the other end is attached to the fixing plate, and one end is attached to the other foot of the opening and closing plate, and the other end is attached to the fixing plate, and opposes the bias spring. And a cover for covering the second opening on the bearing side of the substrate and rotatably holding the shaft of the opening / closing plate. The fixing plate has a bias spring. When,
A damper opening / closing device, which is provided with a rib for holding a shape memory alloy spring at an angle. 2. A bias spring is a coil spring, one end of which is fixed to a substrate and the other end of which is attached to a foot of an opening / closing plate.
The damper opening / closing device according to claim 1, wherein the coil spring has an initial tension and a relatively small spring constant. 3. The shape memory alloy spring is a coil spring,
A heater wire is wound around the wire, crimp terminals are crimped to both ends of the heater wire, and a terminal receiver that fits with the crimp terminal is attached to a lead wire connected to a power source unit. The damper opening / closing device according to claim 1, wherein a fixing plate for fixing the lead wire is provided near the lead wire, the crimp terminal, and the terminal receiver, and the fixing plate is fixed to the substrate.