JPH109315A - Temperature sensitive coil spring and control valve using temperature sensitive coil spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature sensitive coil spring capable of making a two-way shape change without using a bias spring, changing a spring load by means of temperature, and leading no load to zero even at very low temperature, and to provide a control valve using the temperature coil. SOLUTION: Coil formation is applied to a composite wire formed by inserting the core wire 11a of a shape memory alloy into a tube 12a consisting of a spring steel product, or a composite wire formed by inserting a core wire 11b consisting of a spring steel product into the tube 12b of a shape memory alloy. Shape memory treatment in a predetermined shape is applied to the composite wire to obtain a temperature sensitive coil spring 100. The use of the temperature coil spring produces a hydraulic control valve or a water temperature control valve for an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature-sensitive coil spring whose load and shape change depending on ambient temperature, and a control valve using the same.

[0002]

2. Description of the Related Art Conventionally, various temperature response devices using a shape memory alloy have been proposed. For example, a relief valve that changes the relief pressure depending on the temperature, a water temperature control valve that changes the mixing ratio of hot water and cold water depending on the temperature, and a flow path switching valve that switches the flow path according to the temperature, etc. It is.

[0003] By the way, shape memory alloys return to a shape when the temperature becomes higher than the transformation point. However, even when the temperature becomes lower than the transformation point again, the shape memory alloy retains its shape without applying an external force. It is also known that the two-way type returns to the original shape when the temperature returns to a temperature below the transformation point after returning to the shape after the temperature has reached the temperature above the transformation point.

In order to perform a reciprocating operation like an actuator using a one-way shape memory alloy, a device combining a shape memory alloy spring and a bias spring is generally used. In this device, at a temperature above the transformation point, the elastic force of the shape memory alloy spring prevails and operates in the biasing direction of the shape memory alloy spring. Operates in the biasing direction of the spring.

When a two-way shape memory alloy is used, a reciprocating motion like an actuator can be performed by itself without using a bias spring.

As a coil spring made of a two-way shape memory alloy, for example, a coil spring disclosed in Japanese Patent Application Laid-Open No. 7-150314 is known. This is because, after obtaining a TiNi single-phase pitch coil spring, a Ti-Ni alloy wire rod of a specific composition is spirally wound around a columnar body with a pitch interval, and heat-treated at 600 ° C. or more. This is a bidirectional coil spring obtained by winding a pitch around a cylindrical body having a small radius in close contact with each other and subjecting it to a constraint aging treatment at a temperature of 600 ° C. or lower.

[0007]

A temperature responsive device in which a one-way shape memory alloy spring and a bias spring are combined has the advantage that operation is reliable and stable, but is a combination with a bias spring. However, there is a disadvantage in that the installation space is increased, the size of the apparatus cannot be reduced, the number of parts increases, and the assembling work becomes complicated.

Although the two-way shape memory alloy spring can solve the above-mentioned drawbacks, it has a drawback that its operation is apt to be unstable and unstable, and sufficient reliability cannot be obtained. Further, when the temperature becomes extremely low, for example, -20 ° C. or less, there is a problem that the load of the shape memory alloy spring becomes zero.

Therefore, an object of the present invention is to change the shape in two directions without using a bias spring,
Another object of the present invention is to provide a temperature-sensitive coil spring in which the spring load can be changed depending on the temperature and the load does not become zero even at extremely low temperatures, and a relief valve and a water temperature control valve using the same.

[0010]

In order to achieve the above object, the present invention has the following arrangement. That is, a first aspect of the present invention is that a composite wire comprising a core wire and a tube covering the outer periphery thereof, one of the core wire and the tube is formed of a shape memory alloy and the other is formed of a spring steel material is formed into a coil shape. This is a temperature-sensitive coil spring that has been subjected to shape memory processing in a predetermined shape.

A second aspect of the present invention is a temperature-sensitive coil spring in which the core wire is made of a shape memory alloy and the tube is made of a spring steel material.

According to a third aspect of the present invention, there is provided a temperature-sensitive coil spring in which the composite wire is coil-formed so as to have a predetermined coil length, and the shape of the composite wire is subjected to shape memory processing with a free length without load.

A fourth aspect of the present invention is a temperature-sensitive coil spring in which the composite wire is formed into a coil shape and subjected to shape memory processing in a state where the coil is stretched.

According to a fifth aspect of the present invention, there is provided a temperature-sensitive coil spring in which the composite wire is formed into a coil shape and subjected to shape memory processing in a state where the coil is compressed.

According to a sixth aspect of the present invention, in the control valve for relieving fluid when the fluid pressure exceeds a predetermined value, the first to fifth temperature-sensitive coil springs of the present invention are used as a means for pressing a valve body. It is a control valve characterized by having been.

A seventh aspect of the present invention is to move between the hot water outlet and the cold water outlet, change the opening area of each outlet, and change the mixing ratio of hot water and cold water.
In a control valve for controlling water temperature, a valve element is connected and supported by the fourth or fifth temperature-sensitive coil spring of the present invention, and when the temperature is high, the valve element moves in a direction to close the hot water outlet, When the temperature is low, the valve body moves in a direction to close the cold water outlet.

According to the first aspect of the present invention, a coil is formed by using a composite wire having one of a core wire and a tube made of a shape memory alloy and the other made of a spring steel, and is subjected to shape memory processing in a predetermined shape. Therefore, for example, when used as a tension coil spring or a compression coil spring, the coil portion made of a spring steel material always applies a load according to a predetermined spring constant regardless of temperature, and a coil made of a shape memory alloy. The part applies a load that varies with temperature. As a result, it is possible to provide a coil spring in which the load changes depending on the temperature and the load does not become 0 even when the temperature becomes extremely low.

When the initial coil shape and the memory shape are changed, when the temperature is low, the elastic force of the coil portion made of the spring steel material becomes relatively strong. When the temperature is high (when the temperature is equal to or higher than the transformation temperature), the elasticity of the coil portion made of the shape memory alloy becomes relatively strong. As described above, the shape is reversibly changed due to the temperature change, and it can be used alone as a drive source of the temperature responsive actuator. In this case, since the coil portion made of the spring steel material performs the same operation as the bias spring, the operation is stable, the reliability is high, and the stroke can be increased as compared with the conventional two-way shape memory alloy spring. it can.

According to the second aspect of the present invention, since the core wire is made of a shape memory alloy and the tube is made of a spring steel material, the tube can be easily manufactured, and buckling of the tube during coil forming is less likely to occur.

According to the third aspect of the present invention, since the composite wire is coil-formed so as to have a predetermined coil length and is subjected to shape memory processing with a free length without applying a load, it is used as a tension coil spring or a compression coil spring. When used, a coil spring whose load changes with temperature can be provided.

According to the fourth aspect of the present invention, since the composite wire is formed into a coil having a predetermined coil length and subjected to shape memory processing in a state where the coil is stretched, when the temperature is low, the coil length is reduced to the initial coil length. It is possible to provide a coil spring that has a shape close to the shape and has a reversible shape change in which the shape is extended when the temperature is high (when the temperature is equal to or higher than the transformation temperature).

According to the fifth aspect of the present invention, the composite wire is formed into a coil having a predetermined coil length, and is subjected to shape memory processing in a state where the coil is compressed. It is possible to provide a coil spring that has a close shape and has a reversible shape change that becomes a shape compressed when the temperature is high (when the temperature is equal to or higher than the transformation temperature).

According to the sixth aspect of the present invention, by using the first to fifth temperature-sensitive coil springs of the present invention as the valve body pressing means, the pressing load of the valve body changes depending on the temperature. It is possible to provide a control valve suitable for, for example, an oil pressure control valve of an engine, in which the pressing load does not become zero even when the relief pressure changes and the temperature becomes extremely low.

According to a seventh aspect of the present invention, the fourth aspect of the present invention is provided.
Alternatively, the valve body is connected to and supported by the fifth temperature-sensitive coil spring. When the temperature is high, the valve body moves in a direction to close the hot water outlet, and when the temperature is low, the valve body moves in a direction to close the cold water outlet. By doing so, the ratio of cold water increases when the temperature is high, and the ratio of hot water increases when the temperature is low. Therefore, it is possible to provide a control valve that can always adjust so that hot water at a constant temperature flows out. .

[0025]

FIG. 1 shows a specific configuration of a temperature-sensitive coil spring according to the present invention. In FIG. 1, 1
0 is a temperature-sensitive coil spring, 11, 11a and 11b are core wires, 1
2, 12a and 12b are tubes.

In the example shown in FIG. 1A, the core wire 11a is made of a shape memory alloy, and the tube 12a is made of a spring steel material. In the example shown in (b), the core wire 11b is made of a spring steel material, and the tube 12b is made of a shape memory alloy. In the present invention, any of the above (a) and (b) may be used, but (a) is preferable because it is a material that is easy to manufacture the tube 12 and does not easily buckle during coil forming. In the following description, the core wire is assumed to be 11 and the tube is assumed to be 12 in both cases (a) and (b).

The composite of the core wire 11 and the tube 12 may be performed simply by inserting the core wire 11 into the tube 12. However, preferably, the core wire 11 is inserted into the tube 12, and the drawing is performed to form a composite wire. Is preferred. When the core wire 11 is simply inserted into the tube 12, the tube 12 is easily buckled when formed into a coil. However, when a drawn wire is used, such a problem arises because both are integrated and adhered to each other. Because there is no.

The composite wire is formed into a coil as shown in FIG. 1 (c) and subjected to shape memory processing in a predetermined shape, whereby the temperature-sensitive coil spring 100 of the present invention can be obtained. Note that the shape memory processing is, for example, 350 to
It can be carried out by restraining aging at 450 ° C. for about 30 to 60 minutes.

The temperature-sensitive coil spring of the present invention has various types of springs, such as a spring whose load changes with temperature or a spring whose shape changes reversibly with temperature by selecting various coil forming shapes and memory processing shapes. A spring can be provided. 2 to 5 show different embodiments of the temperature-sensitive coil spring of the present invention.

The temperature-sensitive coil spring 101 shown in FIG.
And the composite wire of the tube 12 is obtained by forming a coil with the coil pitch open as shown in FIG. 3A and storing the shape as it is as shown in FIG. At a low temperature, the coil pitch is open as shown in FIG.

When the temperature-sensitive coil spring 101 is used as a compression coil spring, the load is low at low temperatures.
The load can be increased at a high temperature (above the transformation temperature), and the load does not become zero even at an extremely low temperature of -20 ° C or lower.

The temperature-sensitive coil spring 102 shown in FIG.
The composite wire of the tube 12 is obtained by forming a coil in a state where the coil pitch is closed as shown in FIG. 4A and storing the shape as it is as shown in FIG. At a low temperature, the coil pitch is closed as shown in FIG.

By using the temperature-sensitive coil spring 102 as a tension coil spring, the load can be reduced at a low temperature and increased at a high temperature (above the transformation temperature). The load does not become zero even at extremely low temperatures.

FIG. 6 shows the relationship between the deflection and the load of the temperature-sensitive coil springs 101 and 102 shown in FIGS. In the figure, a is the spring characteristic of the coil portion made of a spring steel material, b is the spring characteristic when the temperature is lower than the transformation temperature of the coil portion made of the shape memory alloy, and c is the spring characteristic when the temperature is higher than the transformation temperature of the coil portion made of the shape memory alloy. Spring characteristics. Also, d
Is a spring characteristic obtained by combining a coil portion made of a spring steel material and a coil portion made of a shape memory alloy when the temperature is lower than the transformation temperature, that is, a characteristic obtained by combining a and b. Furthermore, e
Is a spring characteristic obtained by combining a coil portion made of a spring steel material and a coil portion made of a shape memory alloy at a temperature equal to or higher than the transformation temperature, that is, a characteristic obtained by combining a and c.

Therefore, the temperature-sensitive coil springs 101, 10
When the temperature is low (below the transformation temperature), the spring characteristic 2 becomes as shown by d in FIG. 6, and when the temperature is high (above the transformation temperature), as shown by e in FIG. When the deflection amount is constant, the load changes depending on the temperature. Further, even if the load on the coil portion made of a shape memory alloy becomes 0 at an extremely low temperature of -20 ° C. or lower, the load on the coil portion made of a spring steel material does not decrease, so that the load does not become 0. .

Next, the temperature-sensitive coil spring 103 shown in FIG. 4 forms the composite wire of the core wire 11 and the tube 12 with the coil pitch open as shown in FIG. Then, as shown in FIG. 3B, the memory pitch is obtained by performing the storing process with the coil pitch closed.

The temperature-sensitive coil spring 103 returns to the open state at a low temperature (when the temperature is lower than the transformation temperature) as shown in FIG. 4C, and at a high temperature (when the temperature is higher than the transformation temperature). Since the coil pitch is closed as shown in FIG. 4B, the temperature-sensitive actuator can be constituted by itself.

Further, in the temperature-sensitive coil spring 104 shown in FIG. 5, the composite wire of the core wire 11 and the tube 12 is formed into a coil with the coil pitch closed as shown in FIG. As shown in FIG. 2B, the memory pitch is obtained by performing a storage process with the coil pitch opened.

The temperature-sensitive coil spring 104 returns to a closed state at a low temperature (when the temperature is lower than the transformation temperature) as shown in FIG. 4C, and at a high temperature (when the temperature is higher than the transformation temperature). Since the coil pitch is open as shown in FIG. 7B, the temperature-sensitive actuator can be constituted by itself.

FIG. 7 shows the temperature-sensitive coil spring 1 shown in FIG.
4 shows the relationship between the spring length and the load. In the figure, A
Is the initial coil length when the coil is formed, and B is the coil length when the memory processing is performed. In addition, a is a spring length-load characteristic of a portion made of a spring steel material, b is a spring length-load characteristic of a portion made of a shape memory alloy at a low temperature (below the transformation temperature), and c is a portion of a shape memory alloy. It is a spring length-load characteristic at the time of high temperature (when it is higher than the transformation temperature).

The spring length of the temperature-sensitive coil spring 104 is such that the load on the portion made of a spring steel material and the load on the portion made of a shape memory alloy are balanced, so that the temperature is low at a low temperature (below the transformation temperature). Has a length indicated by C in the figure, and has a length indicated by D in the figure at a high temperature (above the transformation temperature). That is, it is possible to provide a temperature-sensitive actuator in which the spring length changes between C and D depending on the temperature.

FIG. 8 shows the temperature-sensitive coil spring 1 shown in FIG.
An embodiment in which 01 is applied to a hydraulic pressure control valve of an engine is shown. In the figure, 21 is an oil circulation channel, 22 is an opening provided in the circulation channel 21, 23 is a spring housing chamber communicating with the opening 22, and 24 is a bypass channel communicating with the opening 22. The ball valve 25 is pressed and arranged so as to close the opening 22 by the temperature-sensitive coil spring 101 arranged in the spring accommodating chamber 23. 26 is
An outer wall that forms the circulation flow path 21, the spring storage chamber 23, and the bypass flow path 24.

The oil is sucked up by a pump or the like arranged in the crank chamber of the engine (not shown), and normally passes through the circulation passage 21 in the direction of arrow A, is cooled through an oil cooler or the like, and is cooled. Circulated to each part.
However, when the hydraulic pressure becomes excessive, the ball valve 25 is pushed down against the urging force of the temperature-sensitive coil spring 101, and at least a part of the oil passes through the opening 22 in the directions of arrows B and C in the drawing, and directly enters the engine. It is returned to each part.

In the above-described hydraulic control valve, when the oil temperature is still low, such as when the engine is started,
When the oil is cooled by the cooler and returned to various parts of the engine, the internal temperature of the engine does not rise easily, and there is a problem that the idling operation time must be extended.

However, in the hydraulic pressure control valve of this embodiment, when the temperature is low (when the temperature is below the transformation temperature of the shape memory alloy), the temperature-sensitive coil spring 1 according to the principle shown in FIG.
01, the ball valve 25 easily separates from the opening 22 and the amount of oil flowing through the opening 22 to the bypass passage 24 increases, so that a large part of the oil is circulated without cooling. Helps raise the internal temperature of the engine.

Further, when the temperature is high (when the temperature is equal to or higher than the transformation temperature of the shape memory alloy), the load of the temperature-sensitive coil spring 101 increases, so that the ball valve 25 can be easily moved from the state in which the opening 22 is closed. Most of the oil
After passing through 1 in the direction of arrow A and passing through an oil cooler, the oil is circulated to various parts of the engine, so that it is possible to prevent the oil temperature from becoming excessively high.

FIG. 9 is a table showing the relationship between temperature and relief pressure by comparing the temperature-sensitive coil spring 101 with a conventional shape memory alloy spring. In the figure, a is a characteristic curve showing the relationship between the temperature and the relief pressure when the temperature-sensitive coil spring 101 of the present invention is used, and b is the relationship between the temperature and the relief pressure when only the shape memory alloy coil spring is used. FIG.

As described above, in the case of using only the shape memory alloy coil spring, the relief pressure can be increased as the temperature rises. However, when the temperature becomes extremely low such as -30 ° C., the load becomes zero and the relief pressure becomes zero. And the oil is all relieved, and there is a risk that the engine will burn.

On the other hand, the temperature-sensitive coil spring 1 of the present invention
When 01 is used, the load on the spring steel material does not change even at a very low temperature of -30 ° C., so that the minimum relief pressure is maintained and there is no danger of engine seizure.

FIG. 10 shows an embodiment in which the temperature-sensitive coil spring 104 shown in FIG. 5 is applied to a water temperature control valve.
In the figure, 31 is a hot water outlet, 32 is a cold water outlet, 3
3 is a mixing chamber, 34 is a cylindrical valve body, 35 is a seal ring, 36 is a mixed water outflow path, and 37 is a casing.
The temperature-sensitive coil spring 104 has one end fixed to the casing 37 and the other end fixed to the valve body 34. Therefore, the valve element 34 moves due to a change in the length of the temperature-sensitive coil spring 104.

The opening area of the hot water outlet 31 and the cold water outlet 32 varies depending on the position of the valve element 34, whereby the ratio of the hot water H and the cold water C flowing into the mixing chamber 33 varies.
The temperature of the mixed water M in which both are mixed changes.

Therefore, if the temperature of the mixed water M is low and not higher than the transformation temperature of the shape memory alloy, the temperature-sensitive coil spring 104
5 becomes shorter as shown in FIG. 5 (c), the valve element 34 moves rightward in the figure to reduce the opening area of the cold water outlet 32 and increase the opening area of the hot water outlet 31. I do.
As a result, the inflow amount of the hot water H relatively increases, and the mixed water M
Temperature rises.

When the temperature of the mixed water M is high and is equal to or higher than the transformation temperature of the shape memory alloy, the spring length of the temperature-sensitive coil spring 104 becomes longer as shown in FIG.
Move to the left in the figure to reduce the opening area of the hot water outlet 31 and increase the opening area of the cold water outlet 32. As a result, the inflow of the cold water C relatively increases, and the temperature of the mixed water M decreases.

As described above, since the mixing ratio between the hot water H and the cold water C is adjusted by the temperature of the mixed water M, the temperature of the mixed water M can be kept constant.

[0055]

[Example] A core wire made of a stainless steel wire having a diameter of 1 mm was inserted into a shape memory alloy tube having an outer diameter of 2.5 mm, an inner diameter of 1.9 mm, and a wall thickness of 0.3 mm, and wound at room temperature to obtain a coil length of 33 mm and a coil diameter of 33 mm. A coil spring having a length of 23 mm and a number of turns of 7.5 was formed.

This coil spring was compressed into a tightly wound state having a coil length of 20 mm, and was subjected to shape memory processing in a restricted state.

As a result, a temperature-sensitive actuator with a stroke of 6 mm having a spring length of 33 mm below 20 ° C. and a spring length of 27 mm above 80 ° C. was obtained.

[0058]

As described above, according to the temperature-sensitive coil spring of the present invention, a coil is formed by using a wire obtained by combining a shape memory alloy and a spring steel, and the coil is formed and stored in a predetermined shape. Therefore, it is possible to provide a coil spring in which the load changes depending on the temperature and the load does not become 0 even when the temperature becomes extremely low. In addition, the shape changes reversibly due to temperature change, and it can be used alone as a drive source for the temperature-responsive actuator. The operation is more stable and more reliable than the conventional two-way shape memory alloy spring. It is possible to provide a coil spring that can be made large.

Further, according to one of the control valves of the present invention, by using the temperature-sensitive coil spring of the present invention, the pressing load of the valve body changes depending on the temperature, so that the relief pressure changes and the extreme pressure changes. It is possible to provide a control valve suitable for, for example, a hydraulic control valve of an engine, in which the pressing load does not become zero even when the temperature becomes low.

Further, according to another control valve of the present invention, by using the temperature-sensitive coil spring of the present invention,
By moving the valve body depending on the temperature and changing the mixing ratio of hot water and cold water, it is possible to adjust so that hot water of a constant temperature always flows out. In addition, since there is no need to combine with a bias spring, the spring accommodating space can be reduced to reduce the size of the device. Since the coil portion of the spring steel works in the same manner as the bias spring, the conventional two-way shape memory alloy can be used. As compared with the case where a spring is used, the operation reliability is higher and the stroke can be made longer.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a temperature-sensitive coil spring of the present invention;
(A) and (b) are cross-sectional views of different examples, and (c) is a side view.

FIG. 2 is a manufacturing process diagram showing one embodiment of the temperature-sensitive coil spring of the present invention.

FIG. 3 is a manufacturing process diagram showing another embodiment of the temperature-sensitive coil spring of the present invention.

FIG. 4 is a manufacturing process diagram showing still another embodiment of the temperature-sensitive coil spring of the present invention.

FIG. 5 is a manufacturing process diagram showing still another embodiment of the temperature-sensitive coil spring of the present invention.

FIG. 6 is a table showing the relationship between the deflection and the load of the temperature-sensitive coil spring of the embodiment shown in FIGS.

7 is a table showing the relationship between the load and the spring length of the temperature-sensitive coil spring of the embodiment shown in FIG.

FIG. 8 is a partially enlarged sectional view showing an embodiment in which the temperature-sensitive coil spring of the present invention is applied to a hydraulic pressure control valve of an engine.

FIG. 9 is a table showing a relationship between temperature and relief pressure in the hydraulic pressure control valve.

FIG. 10 is a sectional view showing an embodiment in which the temperature-sensitive coil spring of the present invention is applied to a water temperature control valve.

[Explanation of symbols]

Reference Signs List 11 core wire 11a core wire of shape memory alloy 11b core wire of spring steel material 12 tube 12a tube of spring steel material 12b tube of shape memory alloy 100, 101, 102, 103, 104 temperature-sensitive coil spring 21 circulation channel 22 opening 23 spring storage chamber 24 Bypass flow path 25 Ball valve 31 Hot water inlet 32 Cold water inlet 33 Mixing chamber 34 Valve element 36 Outflow path of mixed water H Hot water C Cold water M Mixed water

Claims (7)

[Claims] 1. A composite wire comprising a core wire and a tube covering the outer periphery thereof, wherein one of the core wire and the tube is formed of a shape memory alloy and the other is formed of a spring steel material, and is formed into a coil shape. A temperature-sensitive coil spring, which has been subjected to shape memory processing. 2. The temperature-sensitive coil spring according to claim 1, wherein said core wire is made of a shape memory alloy, and said tube is made of a spring steel material. 3. The temperature-sensitive coil spring according to claim 1, wherein the composite wire is coil-formed so as to have a predetermined coil length, and is subjected to shape memory processing with a free length in which no load is applied. 4. The temperature-sensitive coil spring according to claim 1, wherein the composite wire is formed into a coil shape and subjected to shape memory processing in a state where the coil is stretched. 5. The temperature-sensitive coil spring according to claim 1, wherein the composite wire is formed into a coil, and the coil is compressed and subjected to shape memory processing. 6. A control valve for relieving a fluid when a fluid pressure exceeds a predetermined value, as a pressing means of a valve body.
A control valve using the temperature-sensitive coil spring according to claim 1. 7. Adjustment for moving water temperature by moving between a hot water outlet and a cold water outlet, changing an opening area of each outlet, and changing a mixing ratio of hot water and cold water. 6. The valve, wherein the valve body is connected and supported by the temperature-sensitive coil spring according to claim 4 or 5, wherein when the temperature is high, the valve body moves in a direction to close the hot water outlet, and when the temperature is low, the valve body is used. Is moved in a direction to close the cold water outlet.