JPS62175628A - Surface temperature sensing actuator - Google Patents

Abstract

PURPOSE:To obtain a highly accurate and handy temperature sensing actuator, by utilizing a shape memory alloy as thermosensitive element. CONSTITUTION:Firstly, a surface temperature sensing actuator 2 is set on the surface of an object 1 to be detected as shown by (a) and a base section 3 of the shape memory alloy element 5 is put tight on the surface of the object 1. Under such a condition, the temperature rise of the object 1 starts and when the surface temperature is above the transformation point of the shape memory alloy, the temperature of the element 5 rises above the transformation point without delay by the heat transmitted from the base section 3 so that it will return to the initial shape (A) memorized. At this point, as spiral spring as deforming force adding means 6 is elongated by return force and a display mark as a means 7 of indicating the arrival at the specified return shape will appear at a display window 10. Thus, it is possible to detect quickly and surely that the surface temperature of the object 1 reaches the temperature equivalent to the transformation of the shape memory alloy.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is applicable to mechanical devices such as injection molding machines and motors,
Alternatively, the present invention relates to a simple surface temperature sensing actuator that can be used repeatedly and quickly and reliably detects and displays that the surface temperature of various objects has reached a specific temperature.

<Background Art> For example, in the case of plastic injection molding work, the injection molding machine's sleeve and mold are preheated to a predetermined temperature before starting the injection work. Therefore, in this case, it is necessary to quickly and reliably detect that the sleeve or mold has reached a predetermined temperature.

Conventionally, as a means for detecting that the temperature of each part of such an injection molding machine has reached a predetermined temperature, it has been common to employ a temperature measuring device that combines a thermocouple and a millivolt recorder.

However, the method of detecting temperature using a thermocouple device requires electrical wiring that incorporates a millivolt recorder, etc., and it has been pointed out that this wiring poses a considerable hindrance to injection molding work. Since the price of the temperature detection device as a whole is quite high, there is a strong demand for improvements in the field where small-scale injection molding machines are mainly used.

Note that methods such as using an infrared thermometer or using a heat label as a general means of detecting the surface temperature of an object are also known, but infrared thermometers are very expensive and their uses are inevitably limited. On the other hand, heat labels cannot be used repeatedly, and it is difficult to accurately determine the point at which a predetermined temperature is reached, so they cannot be said to be satisfactory in terms of cost and usage.

Apart from these, in recent years, temperature sensing switches that utilize the properties of shape memory alloys have been proposed (for example,
(Please refer to Japanese Patent Application Laid-open No. 65884 and Japanese Patent Application Laid-open No. 126273/1983), but these are all devices that cannot detect the ambient temperature, and cannot accurately detect the temperature of the surface of an object. I couldn't.

<Means to Solve the Problems> Based on the above-mentioned problems found in conventional temperature detection devices, the present inventors have developed a method to quickly and efficiently detect when the surface temperature of various objects has reached a specific temperature. In order to provide a simple Hiko surface temperature detection device that can detect and display data reliably, we are working hard to utilize shape memory alloys as temperature-sensitive elements, which do not require special electrical wiring and can be used repeatedly. As a result of the research, the following findings (α) to () were obtained.

In other words, (α) In order to correctly detect the surface temperature using a shape memory alloy as a temperature sensing element, it is necessary to provide a sensing part on the surface of the target object to sufficiently bring the shape memory alloy element into close contact over a relatively wide area. (b) Therefore, in order to satisfy this condition, it is desirable that the shape memory alloy element be in the form of a plate; (C) When the shape memory alloy is used as an actuator for sensing the surface temperature of an object, If the operation of the shape memory alloy element (return to the memorized shape) occurs in the direction away from the object surface, the response to the surface temperature will be incomplete and accurate temperature detection will not be possible.However, by reversing this operation direction, If a shape memory alloy element is used, which has an initial shape that is in close contact with the surface of a target object and then is deformed into a shape that is separated from the surface of the target object, the element will be able to move onto the surface of the target object by the operation of the shape memory alloy element. By the way, in order to use shape memory alloy elements repeatedly, it is necessary to raise the temperature to above the transformation temperature. The shape memory alloy element that has returned to its initial shape must be returned to its deformed shape before activation after the temperature has decreased.

If a thin shape memory alloy element is used or the external deformation force (such as from a coil spring or helical spring) is large, there is a risk that the shape memory alloy element may be locally deformed beyond its recovery limit. Even in such a case, the above danger can be completely eliminated by arranging a guide member (for example, a contact support member having an arc-shaped surface) in a direction opposite to the shape memory alloy element in the direction in which it is deformed by external force. to be wiped out.

This invention was made based on the above findings,
As illustrated in the schematic configuration diagram shown in FIG. ) is memorized and then deformed (B) so as to be separated from the object surface. A deforming force applying means (helical spring) 6 engaged with the shape memory alloy element actuating section 4 to return the shape memory alloy element 5 which has returned to the shape memory alloy element 5 to the deformed shape (B) before actuation after the temperature decreases; , a predetermined return shape attainment display means (display mark) 7 for indicating that the shape memory alloy element 5 provided in the deformation force applying means 6 has returned to the predetermined shape.
or, as shown in FIG. 3, a deformation guide disposed opposite to the shape memory alloy element 5 in order to prevent large local deformation from occurring due to the deformation force by the deformation force applying means 6. The present invention is characterized by the fact that it also includes a member 8.

In the drawings, the reference numeral 9 is a case for the surface temperature sensing actuator, the reference numeral 10 is a display window, and the reference numeral 11 is a deformation force adjustment screw.

Here, the "shape memory alloy" includes a Ni-Ti alloy with a concentration of around 50 atomic percent, and an Au-cd gold alloy CS.
-Al -Ni alloy, (:x -Z?$ alloy, etc. (DI
/ may be employed, and may be selected as appropriate depending on the application (required display temperature, etc.).

In addition, in addition to spiral springs and coil springs, the "deformation force applying means" for returning the shape memory alloy element to the deformed shape before the operation after the operation is completed include a weight or a combination of a weight and a lever. From an economic point of view, it is preferable to adopt

The simplest example of the "predetermined return shape attainment means" is, for example, the display mark (mark) 7# attached to the helical spring as shown in FIGS. 1 and 3.
It goes without saying that a "display" or "display bar" etc., which will be explained later, may be employed, and an electrical display device may also be attached.

On the other hand, FIG. 2 is a schematic configuration diagram showing the operating state of the surface temperature sensing actuator shown in FIG. 1, which is an example of the present invention.
The figure is a perspective external view of the surface temperature sensing actuator shown in FIG. 3, which is another example of the present invention, before operation, FIG. 5 is a schematic configuration diagram showing its operating state, and FIG. FIG. 1 is a perspective view of the external appearance (during operation). In order to detect when the surface temperature of the object 10 heated by the surface temperature sensing actuator 2 exemplified above reaches a predetermined value, first, FIG. As shown in the figure, the surface temperature sensing actuator 2 is set on the surface of the object 1, and the base 3 of the shape memory alloy element 5 is brought into close contact with the surface of the object 1.

In this case, FIG. 5 (which is an example of a bottom view of the surface temperature sensing actuator shown in FIGS. 3 to 6, but may even be used as an example of a bottom view of the surface temperature sensing actuator shown in FIGS. 1 to 2) As shown, a magnet 12 is attached to the bottom of the surface temperature sensing actuator 2.
If the base 3 of the shape memory alloy element 5 is attached to the surface of the target object, it will be easier to bring the base 3 of the shape memory alloy element 5 into close contact with the surface of the target object, and it will also be easier to set the surface temperature sensing actuator 20 on a surface other than the horizontal surface. It's not something you can do.

Now, when the temperature of the object 1 starts to rise in this state and its surface temperature reaches a temperature higher than the transformation point of the shape memory alloy, the shape memory alloy element 5 also reaches the transformation point without any delay due to rapid heat transfer from the base 3. The temperature rises to a temperature above and attempts to return to the memorized initial shape (A), but at this time, the surface temperature sensing actuator shown in FIG. In the case shown in FIG. 3, as shown in FIGS. 5 and 6, the helical spring serving as the deforming force applying means 6 is stretched by the return force, and the predetermined return shape reaching display means 7
Since the barrel display mark appears on the display window 10, it is possible to quickly and reliably detect that the surface temperature of the object 1 has reached a temperature corresponding to the transformation point of the shape memory alloy. Note that at this time, the shape-returning operation of the shape-memory alloy element 5 progresses in a direction such that the shape-memory alloy element 5 comes into stronger (more) contact with the surface of the object 1, so that the shape-memory alloy element 5 moves from the object surface to the shape-memory alloy element. The heat transfer will be even more sufficient.

The response of the element will not be incomplete.

After this, when the surface temperature of the object 1 becomes lower than the transformation temperature of the shape memory alloy, the temperature of the shape memory alloy element 5 also decreases and its shape restoring force disappears, so the shape memory is stored by the helical spring serving as the deformation force applying means 6. The alloy element 5 is returned to the deformed shape (B) before activation, and is ready for the next repeated use.

When this shape memory alloy element is returned to its pre-operation shape, there is a risk that large local deformation (strain rate of 7 degrees) may occur, resulting in incomplete shape recovery upon subsequent operation. However, as shown in FIGS. 3 to 6, a deformable guide member 8 having a circular arc shape or the like is placed opposite the shape memory alloy element 5.
By arranging the shape memory alloy element, such adverse effects can be completely prevented, and stable performance can be maintained even if the thickness of the shape memory alloy element is reduced.

By the way, FIGS. 8, 9, and 10 are schematic configuration diagrams showing still other examples of the surface temperature sensing actuator according to the present invention, and FIG. 8 shows a coil spring as the "deformation force applying means". Fig. 9 uses a "combination of a weight 13 and a lever 14" as a "deformation force applying means" and a weight as a "means for indicating that the shape memory alloy element has reached a predetermined return shape." 10 uses a "combination of a weight 13, a lever 14, and a wire rod 16" as a "deformation force applying means" and "returns the shape memory alloy element to a predetermined value." A display rod 17 (connected to a lever 14) is used as a "shape attainment display means".

In addition, what is indicated by the reference numeral 18 in the drawings is a lever 1.
4 rotation axis.

In addition, Fig. 8 (α), Fig. 9 (α) and Fig. 10 (α)
8(6), 9(b) and 10(b) show the state before activation of each surface temperature sensing actuator.
It goes without saying that ) shows their operating states, and the functions of the above-mentioned surface temperature sensors should be fully understood from the description of each of these drawings.

The sensing temperature of the surface temperature sensor according to the present invention is determined by the type of shape memory alloy element used, but if you want to change the sensing temperature, you can change the alloy type or composition of the shape memory alloy element used. Of course, the response speed of the sensor can also be changed by adjusting the bias applied by the deforming force applying means. Note that the material of the housing and deformation guide member of the sensor is not particularly limited, but is generally made of plastic or metal.

<Overall Effects> As explained above, according to the present invention, it is possible to detect when an injection molding machine, a heat press machine, etc. have reached the appropriate temperature for starting work, and to prevent overheating of motors and disconnectors at substations. Not only can it accurately sense, but it can also display the danger of overheating in household and commercial irons, detect when an electromagnetic cooker has reached the appropriate temperature, and detect when the water in a bathtub has reached a predetermined temperature (in this case, ,
Float a suitable container on the surface of the hot water and place a temperature sensing actuator on top of it), or place it on top of an ice cream, etc. to be cooled in the refrigerator (you can also put it through vinylidene chloride wrap, etc.)
This provides extremely useful effects in industry and daily life, such as providing a highly accurate and simple surface temperature sensing actuator that can detect when food is ripe.

[Brief explanation of drawings]

1 and 2 are schematic diagrams showing one example of the surface temperature sensing actuator according to the present invention, FIG. 1 is a schematic configuration diagram showing a state before operation, and FIG. 2 is a schematic diagram showing a state during operation. 3 to 6 are schematic diagrams showing other examples of the surface temperature sensing actuator according to the present invention, FIG. 3 is a schematic diagram showing the state before operation, and FIG. 4 is a schematic diagram showing the state before operation. Fig. 5 is a schematic configuration diagram showing the state in operation, Fig. 6 is a schematic perspective view of the appearance showing the state in operation, and Fig. 7 is the same as shown in Figs. 3 to 6. A schematic bottom view showing an example of a surface temperature sensing actuator with an adsorption magnet attached to the bottom outer surface; FIGS. 8 to 10 are schematic views showing still another example of the surface temperature sensing actuator according to the present invention; Figure 8 (), Figure 9 ()
10() are schematic configuration diagrams showing the state before operation, and FIGS. 8(), 9(), and 10() are respective schematic configuration diagrams showing the state during operation. In the drawings, 1... Surface temperature sensing target object, 2... Surface temperature sensing actuator, 3... Base of shape memory alloy element, 4... Actuating part of shape memory alloy element, 5... Shape memory alloy element, 6... Deformation force applying means (helical spring), 6... Deforming force applying means (coil spring), 7... Predetermined return shape attainment indicating means (display mark), 8... Deformation Guide member, 9... Case of surface temperature sensing actuator, 10... Display window, 11... Deformation force adjustment screw, 12
...magnet, 13...weight, 14...lever,
15...Display group, 16...Wire rod, 17...
Display rod, 18... Lever rotation axis, A... Initial shape, B... Deformed shape. Watari 3 diagrams Broom 8 diagrams

Claims (2)

[Claims] (1) A plate having a base that is brought into close contact with the surface of the object to be temperature measured, and an actuating portion that is deformed so as to be separated from the surface of the object to be temperature measured after the initial shape of the object that is in close contact with the surface of the object to be measured is memorized. the shape memory alloy element, and the shape memory alloy element actuating section for returning the shape memory alloy element, which has been heated to a temperature higher than the transformation temperature and returned to its initial shape, to the deformed shape before actuation after the temperature is lowered. A surface temperature sensing actuator comprising: a deforming force applying means engaged with each other; and a means for indicating that a shape memory alloy element has reached a predetermined return shape provided in the deforming force applying means. (2) A plate having a base that is brought into close contact with the surface of the object to be temperature measured, and an actuating portion that is deformed so as to be separated from the surface of the object to be temperature measured after the initial shape of the object that is in close contact with the surface of the object to be temperature measured is memorized. the shape memory alloy element, and the shape memory alloy element actuating section for returning the shape memory alloy element, which has been heated to a temperature higher than the transformation temperature and returned to its initial shape, to the deformed shape before actuation after the temperature is lowered. The engaged deformation force applying means, a deformation guide member disposed opposite to the shape memory alloy element to prevent large local deformation from occurring due to the deformation force caused by the deformation force, and the shape memory alloy element provided in the deformation force applying means. A surface temperature sensing actuator comprising: means for indicating that a predetermined return shape has been reached.