JPH0451186B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal actuator using a shape memory alloy, and a preferred application thereof is a fire and smoke damper used in air conditioning or ventilation ducts.

As an example of using shape memory alloys for adjusting the opening and closing of dampers, etc., Public Utility Model Publication 1987-
There are No. 61429, No. 12564 of 1983, and No. 12565 of 1983.
In all of these, the shape memory alloy itself or a member rigidly fixed to the shape memory alloy is used as the opening/closing member of the damper. However, with this method, it is difficult to obtain a large opening/closing angle of the damper. Furthermore, it is necessary to make the shape memory alloy itself large,
becomes significantly more expensive. Furthermore, since the damper itself is consumable, repair costs become extremely high. Therefore, it is difficult to use as an emergency damper for general air conditioning equipment, and cannot handle large air volumes.

It is an object of the present invention to avoid the above-mentioned drawbacks and to provide a shape memory alloy as an inexpensive component of a damper.
To provide a fire and smoke prevention damper having a structure capable of controlling opening and closing at 90 degrees.

Embodiments and drawings illustrating the present invention will be described. For clarity of illustration, similar parts or parts are indicated by the same reference numerals.

Figures 1 and 2 show the first part of the fire and smoke prevention damper of the present invention.
In this embodiment, a shaft 3 of a damper 2 is rotatably supported within a damper casing 1. The vanes 4 are shown in the open position. A lever 5 is fixed to a portion of the shaft 3 that protrudes outside the casing 1. Lever 5
The bias spring 6 is attached to one end and the other end is attached to the casing 1 to keep the vane 4 in the open position. Attach a stopper (not shown) to the casing 1, and
to determine the fully open position of the blade 4.

A shape memory alloy member 10 is attached to the other end of the lever 5. The shape memory alloy member 10 enters the casing 1 from the pivot point 11 with the lever 5 through the guide wheel 12 outside the casing 1, passes through the guide wheel 13 inside the casing 1, exits the casing 1 again, and enters the bracket 14. Installed.

During operation, when the airflow temperature within the damper casing 1 does not reach a predetermined value, the shape memory alloy member 1
0 maintains the shape shown in the figure, and the blades 4 of the damper 2 maintain the fully open position. If the temperature inside the damper casing 1 rises and exceeds a predetermined value, the shape memory alloy member 10
returns to its original shape. That is, the straight portions 15 and 16 within the casing 1 are bent. This causes the member 10 to move the lever 5 to the second position by the pivot portion 11 against the spring 6.
Rotate it clockwise in the figure to reach the fully closed position shown by the dotted line in FIG. In this position, one end of the lever 5 pushes the spring pawl 18 of the manual locking device 17 into the fully closed position, and the pawl 18 holds the lever 5 in the fully closed position.

Normally, the airflow temperature inside the casing 1 is room temperature or heating/cooling temperature, which is significantly different from the temperature in an emergency for the purpose of fire and smoke prevention, so the problem of slight operating temperature error does not occur and the structure is extremely simple. It operates as a reliable safety device. When the emergency condition is lifted, the airflow duct is inspected, and when safety is confirmed, the manual locking device 17 is opened, and the spring 6 pulls the lever 5 to return the vane 4 to the fully open position.

FIGS. 3 and 4 show a second embodiment of the present invention. Similar to the embodiment shown in FIGS. 1 and 2, a lever 5 fixed to the damper shaft 3 and placed outside the casing 1 is pulled by a spring 6. Keep the vane 4 in the fully open position. The shape memory alloy member 10 is connected to the pivot portion 11 at the other end of the lever 5, enters the casing 1 through the guide wheel 12, and is attached to the bracket 14 through the guide wheel 13. According to the present invention, a circuit 20 is connected to the shape memory alloy member 10. A closing command switch 21 and a heating power source 22 are connected in series to the circuit 20.

When the temperature inside the casing 1 exceeds a predetermined value, the shape memory alloy member 10 bends, and the lever 5 is rotated clockwise in FIG.
is the fully closed position. This point is similar to the embodiments shown in FIGS. 1 and 2.

Furthermore, if the switch 21 is turned on as required, a current flows through the shape memory alloy member 10 and heats it. If the temperature of the member 10 exceeds a predetermined value, the lever 5 is similarly rotated to bring the blade 4 to the fully closed position. When the lever 5 pushes down the pawl 26 of the locking device 25 to reach the fully closed position, the pawl 26 returns to maintain the position of the lever 5 shown by the dotted line in FIG. 4. A limit switch or a separate switch in combination with the movement of pawl 26 turns off switch 21 to prevent overheating of member 10. A return command switch 28 and an operating power source 29 are connected to the circuit 27 connected to the locking device 25.
When the switch 28 is turned on, the pawl 26 is retracted and the lever 5 is released. Bias spring 6 forces lever 5 into the fully open position.

With the above configuration, when the airflow temperature inside the casing 1 does not rise but dense smoke flows in, if the switch 21 is turned on by remote control, the lever 5 is turned on.
is rotated to bring the damper blade 4 to the fully closed position.
When the switch 28 is turned on, the lever 5 is moved by the spring 6.
returns to the fully open position. It is easy to centrally control the on/off of the switches 21 and 28.

FIG. 5 shows a third embodiment of the invention. A bias spring 6 attached to one end of a lever 5 fixed to the shaft 3 of the damper 2 within the damper casing 1 exerts a force in the direction of keeping the vane 4 in the closed position. The damper vanes 4 are in the open position in the illustrated state.

The shape memory alloy member 30 has one end pivotally supported on the lever 5, passes through a guide wheel 31, and the other end is attached to a fixture 32 with a temperature fuse. In this case, only the temperature fuse is placed inside the casing 1. Unlike the examples shown in FIGS. 1 to 4, the shape memory alloy member 30 is in a straight state at room temperature, and becomes curved as shown in FIG. 5 when the temperature rises.

According to the present invention, a circuit 33 is connected to the shape memory alloy member 30, and a return command switch 3 is connected to the circuit 33.
4. Connect the heating power source 35. The locking device 36 has a pawl 37 which can be retracted by a temperature sensor 38. Additionally, a circuit 40 is connected to the locking device 36.
An operation command switch 41 and an operation power source 42 are connected in series to the circuit 40. When the switch 41 is turned on, the claw 37 is retracted.

If the temperature of the air flow inside the casing 1 increases, a temperature sensor 38 in the locking device 36 will cause the pawl 37 to retract. Furthermore, the temperature fuse attached to the fixing metal fitting 32 at one end of the shape memory alloy member 30 melts, causing the member 30 to melt.
is no longer fixed. The lever 5 is therefore free to rotate and the spring 6 moves the vane 4 into the closed position.

In addition to the above-mentioned emergency operation, it is possible to perform a command operation according to the present invention. First, to move the damper vane 4 from the open position to the closed position, the actuation command switch 41 is turned on and the pawl 37 of the locking device 36 is retracted. In this case, the shape memory alloy member 30 is almost straight, but since the pivot end 11 of the lever 5 is located upward as shown by the solid line in FIG. , spring 6 pivots lever 5 into the closed position.

In order to move the blade 4 from the closed position to the open position,
Turn on the return command switch 34. The shape memory alloy member 30 is heated by the current from the power source 35, and the member 30 assumes the shape at high temperature, that is, the state shown in FIG. It is held by the claw 37 of the device 36. This signal turns off the switch 34. Thus, contrary to the first and second embodiments described above, the shape memory alloy member 30 is used to move the damper vane 4 from the closed position to the open position, and the spring 6 is used to move the vane 4 from the open position to the closed position. used for moving. Similarly, the damper blades close in an emergency.

According to the present invention, a fire and smoke prevention damper can be simplified and miniaturized, and a test operation for opening and closing the damper blade can be performed appropriately and easily by remote control.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the first embodiment of the fire and smoke prevention damper of the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is a sectional view of the second embodiment, and Fig. 4 is a sectional view of the third embodiment. FIG. 5 is a side view of the damper of the third embodiment. 1...damper casing, 2...damper, 3...
Damper shaft, 4... Damper blade, 5... Lever, 6
...Bias spring, 10,30...Shape memory alloy member, 12,13,31...Guide wheel, 17,25,3
6... Lock device, 18, 26, 37... Claw, 20,
27, 33, 40...circuit, 21, 28, 34, 4
1...Switch, 22, 29, 35, 42...Power supply,
32...Temperature sensor.

Claims (1)

[Claims] 1 Damper blade 4 inside damper casing 1
In a damper provided with a lever 5 fixed to the damper blade 4 and provided on the casing 1, and a spring 6 for moving the lever 5 to the closed position, one end is connected to the end of the lever via a guide wheel 31. and a shape memory alloy member 30 coupled to a fixing metal fitting 32 with a temperature fuse whose other end is fixed to the casing;
Temperature sensor 3 that locks the lever 5 in the open position
8, a return command switch 34 for heating the shape memory alloy member 30, a circuit device 33 comprising a heating power source 35, and an operation command switch for opening the lock device 36. 41, a fire and smoke prevention damper comprising a circuit device 40 equipped with an operating power source 42;