JPH0138309Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telescopic operation adjustment device using a shape memory alloy.

Shape memory alloys operate in a constant manner depending on temperature, so they are used in various industrial equipment that needs to operate depending on atmospheric temperature, but if they are used as rods or wires, they do not expand or contract. Because of its small size, it is generally used in the form of a coiled spring. On the other hand, the operating temperature of such shape memory alloys is determined by the alloy composition;
For example, Al
If the component weight changes by only 1%, the operating temperature will change.
For example, a 170°C change in Zn and a 1% change in Zn component weight will cause a 60°C change in the operating temperature. Therefore, even a small difference in the alloy composition can cause a large change in the operating temperature. It is difficult to accurately control the temperature of the shape memory alloy, and for this reason, conventionally, the operating temperature of shape memory alloys has been adjusted by attaching a weight to a movable seat that slides or rotates with the operation of the shape memory alloy, and applies a constant load to it. mosquito,
This was accomplished either by attaching a bias spring or by using a combination of both. Figure 1 is a characteristic diagram of the temperature T and the displacement L of the shape memory alloy when the activation start temperature is moved and adjusted from point A to point B using this method. When using the conventional method (curve B), compared to the case where the operating temperature is not adjusted (curve A), the effective displacement amount is reduced because the load is constantly applied, and as a result, reliable operating force is applied to the equipment used. In addition, since the displacement amount/temperature gradient (ΔL/ΔT) is decreasing, there is a large variation in the activation start time, such as a delay.Furthermore, although not shown in the figure, However, coil springs made of shape memory alloys also have drawbacks such as deterioration in durability and fading of coil springs.

The present invention eliminates the disadvantages of adjusting the operation of coil springs made of shape memory alloys, ensures reliable displacement even when the operation start temperature is changed, has no variation in operation start time, and is durable. The object of the present invention is to provide an improved operation adjustment device.

The present invention provides a device in which a coil spring made of a shape memory alloy is installed between a fixed seat and a movable seat, and the movable seat is slid by the expansion and contraction of the coil spring, in which a magnet that closely contacts the fixed seat is formed at least in the lower part. The shaft rod is inserted through the movable seat and attached, and a stopper is provided on the top of the shaft rod, the stopper being located below the maximum extension of the coil spring made of a shape memory alloy and temporarily stopping the slide of the movable seat. By attaching the device, the above object has been achieved.Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 4.

In FIGS. 2 and 3, a coil spring 1 made of a shape memory alloy is installed between a plate-shaped fixed seat 2 and a movable seat 3, and is expanded and contracted to cause the movable seat 3 to slide up and down. ing. An actuator (not shown) or the like is connected to the movable seat 3, and when the movable seat 3 slides, actuating force is transmitted to the device. The coil spring 1 made of a shape memory alloy is attached between the movable seat 3 and the fixed seat 2 by having its upper end hooked to a pair of left and right hooks 4, 4 attached to the lower surface of the movable seat 3. However, a shaft rod 5 is inserted into this coil spring 1. A magnet 6 such as a permanent magnet or an electromagnet is attached to the lower part of this shaft rod 5, and this magnet 6 is connected to a second
When the coil spring 1 shown in the figure is made of a shape memory alloy and is not activated, its magnetic force causes it to come into close contact with the upper surface of the adjustment seat 7, which is screwed onto the fixed seat 2. Further, the shaft portion 5a of the shaft rod 5 is inserted into an insertion hole 3a formed through the movable seat 3, so that the movable seat 3 slides in the axial direction of the shaft portion 5a. However, this slide can be temporarily stopped by a stopper 8 consisting of a nut screwed onto the upper part of the shaft 5. This stopper 8 is attached to the shaft rod 5 at a position below the maximum elongation of the coil spring 1 made of a shape memory alloy, so that even if the coil spring 1 is elongated due to temperature sensing, The amount of extension does not reach the maximum immediately, and the extension force of the spring 1 is accumulated when the movable seat 3 collides with the stopper 8.
When this elongation force overcomes the magnetic force of the magnet, the elongation reaches a maximum as shown in FIG. 3.

As described above, the present invention is characterized in that the operating temperature of the shape memory alloy is adjusted by the magnet, and after the start of operation, the load due to the magnetic force is released, so that the above-mentioned drawbacks can be overcome.

In addition, 9 in the figure is a buffer coil inserted on the shaft rod 5 between the magnet 6 and the movable seat 3, and 10, 10 shown by a chain line indicates the slide of the movable seat 3. A plurality of long guide rods connect the movable seat 3 and the fixed seat 2 for stability.

Next, an explanation will be given of the operation in which the operating temperature is adjusted by the present embodiment configured as described above.

When the shape memory alloy senses the operating temperature in the unactuated state shown in FIG. 2, the coil spring 1 expands and causes the movable seat 3 to slide upward. As described above, the movable seat 3 collides with the stopper 8 and is temporarily stopped, and as a result, the spring extension force is accumulated in the coil spring 1, and this extension force is screwed onto the fixed seat 2. When the magnetic force becomes larger than the magnetic force of the magnet 6 that is in close contact with the adjustment pedestal 7, the magnet 6 separates from the adjustment pedestal 7, and the coil spring 1 made of a shape memory alloy is attached to the shaft rod 5 as shown in FIG.
The movable seat 3 is raised together with the movable seat 3, and operation becomes possible. Therefore, the operation of this embodiment is not performed during the time period during which the sliding of the movable seat 3 is temporarily stopped, and the operating temperature can be adjusted. In this case, by raising and lowering the adjustment base 7 and the stopper 8 to adjust the screwing position, it is also possible to change and adjust the operating temperature.

As described above, according to this embodiment, the expansion of the coil spring made of a shape memory alloy is temporarily stopped by the magnetic force and the stopper, so that the operation start temperature can be adjusted. Furthermore, the curve C in Figure 4 is
In FIG. 2, after the movable seat 3 collides with the stopper 8, the coil spring 1 is expanded to the state shown in FIG. Even if the temperature is changed from point A to point B, the decrease in the effective displacement of the shape memory alloy is extremely small, making it possible to reliably transmit the operating force. In addition, as mentioned above, the extension force is accumulated, the operation starts instantaneously, and the displacement/temperature gradient (ΔL/ΔT) increases, so that when the movable seat 3 collides with the stopper 8. There is no variation at the start of operation. Furthermore, after the coil spring 1 made of shape memory alloy is activated, the magnet is also separated from the adjustment pedestal 7 and no load is applied to the coil spring, which improves durability and prevents wear due to long-term use. have

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, the shaft rod may not be inserted into the coil spring made of a shape memory alloy, but may be attached to the outside of the coil spring, The adjustment pedestal and the shock absorbing coil spring may also be removed if they do not interfere with operation, and the entire shaft rod may be formed into a magnetic bar, and in the case of such a magnetic bar, moldability is easy. . Furthermore, the stopper may not be formed with a nut, but may be simply a plate and fixed to the shaft rod by screwing, welding, etc., and the magnetic force can be adjusted not only by adjusting the screwing position of the adjustment pedestal, but also by using a non-magnetic material. It is also possible to change the surface area by attaching a piece to a magnet, or by replacing the magnet.

As explained in detail above, according to the present invention, not only is it possible to adjust the operating temperature, but also operation is reliable at the adjusted temperature, there is no variation in operating time, and the shape has improved durability. This has the advantage that it is possible to provide an operation adjustment device for a coil spring made of a memory alloy.

[Brief explanation of the drawing]

Both FIG. 1 and FIG. 4 are temperature-displacement characteristic diagrams of shape memory alloys, where A shows the curve without load, B shows the conventional curve, and C shows the curve of the present invention. 2 and 3 are side views showing the operation of an embodiment of the present invention. 1... Coil spring, 2... Fixed seat, 3... Movable seat, 5... Shaft rod, 6... Magnetic force, 8... Stopper.

Claims (1)

[Scope of utility model registration request] A device in which a coil spring made of a shape memory alloy is installed between a fixed seat and a movable seat, and the movable seat is slid by the expansion and contraction of the coil spring, the shaft rod having at least a lower portion formed with a magnet that closely contacts the fixed seat. is installed by penetrating into the movable seat,
A telescoping operation adjustment device characterized in that a stopper is attached to the upper part of the shaft rod, the stopper being located below the maximum extension of the coil spring made of a shape memory alloy and temporarily stopping the slide of the movable seat.