JPH11287356A - Three-way switching valve using shape memory alloy - Google Patents

Abstract

(57) [Problem] To provide a device which does not generate vibration and noise when a three-way switching valve using a shape memory alloy spring is operated. SOLUTION: In a valve body 2 provided with one inlet 3 and first and second outlets 5, 14, a valve body 16 having valves opposed to both outlets at both ends is slidably provided. A bias spring 30 for urging the valve body 16 to open the first discharge port 5 direction and close the second discharge port 14, and opposes the bias spring 30. A three-way switch using a shape memory alloy spring having a spring constant higher than that of the bias spring and having a first discharge port 5 closed and a second discharge port 14 opened at a predetermined temperature or higher. in the valve, the flow channel buffer unit 1 to the first discharge port side flow path
7 , 18 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-way switching valve which uses a shape memory alloy when switching a three-way valve depending on fluid temperature.

[0002]

2. Description of the Related Art One valve body is provided with three inlets and outlets, one of which is used as a fluid inlet, and the other two are used as fluid outlets. A three-way valve that selectively switches to any one of outlets is used in various fields. FIG. 5 shows an example of the use of such a three-way valve.

That is, a supply path 51 of tap water is connected to a first inlet 53 of a four-way valve 52, a connection line from a first discharge port 54 is connected to a water purifier main body 55 containing activated carbon, and its outflow is performed. The path 56 is connected to the inlet 58 of the three-way switching valve 57, and the first outlet 60 of the three-way switching valve 57 is connected to the second outlet of the four-way valve 52.
To the inflow port 61, and this is supplied from the second discharge port 62 as purified water. In the case of using such a water purifier, since the organic matter in the water adheres to the activated carbon and gradually clogs due to the long-term use of the water purifier, and the function of the activated carbon deteriorates, the water purifier body is used. 55
By activating the heater provided in the apparatus and supplying high-temperature water to the activated carbon, the filter is activated and the water purifier is cleaned. At this time, since the hot water discharged from the water purifier main body 55 is contaminated, it is preferable to discharge the hot water from another drainage system. Therefore, the three-way switching valve 57 is switched so that the hot water from the inlet 58 is supplied to the three-way switching valve 57. From the second discharge port 63 to the water distribution pipe 64.

In the three-way switching valve used in such a device, it is necessary to switch the flow path from the first discharge port 60 to the second discharge port 63 when the heater built in the water purifier main body 55 is operated. However, if the operation of the heater is detected, or the temperature of the fluid from the water purifier main body 55 is detected, and the three-way switching valve 57 is switched by an electromagnetic device, many components and a control device are required. It has to be expensive. As a countermeasure, a three-way switching valve using a shape memory alloy spring has attracted attention as a three-way valve that automatically switches according to temperature.

On the other hand, conventionally, there has been a need to switch the three-way valve automatically at a predetermined temperature not only in the above-mentioned fields but also in various fields. Therefore, three-way valves using a shape memory alloy spring have been widely used. Proposed. For example, a three-way switching valve as disclosed in Japanese Utility Model Laid-Open Publication No. Sho 59-51265 has been proposed. This three-way switching valve is provided with an inlet at a central side wall in a cylindrical valve body, a first outlet at one end face of the valve body, and a second outlet at the other end face. Has a valve body with valves at both ends facing both outlets,
Provided slidably in the state of being supported by the center support, provided with a bias spring that constantly biases this valve body toward one of the discharge ports, and at a predetermined temperature or higher, a spring constant stronger than the above bias spring is provided. A spring made of a shape memory alloy having an opposite end, whereby at a predetermined temperature or less, one outlet is closed by a valve body by a bias spring, and the other outlet is open, and the temperature of the fluid is increased. When the temperature is equal to or higher than a predetermined temperature, the shape memory alloy spring has a strong spring constant, so that the one outlet is opened against the biasing force of the bias spring and the other outlet is closed, whereby the flow path is Is switched.

[0006]

In the above three-way switching valve using the conventional shape memory alloy spring, particularly when the three-way switching valve is provided in a pipe of the water purifier as described above, When the pressure drops from the drain mode to below the predetermined temperature, the flow path is switched by the operation of the shape memory alloy spring, and the mode is switched to the water purification mode, the valve is turned off from the state where the pressure at the inlet is initially high and the pressure in the drain is low. At the moment of the change, the valve on the water purification side opens, so that the pressure in the drainage channel becomes higher, causing pulsation in the pipe, causing a hunting phenomenon in which the valve body repeatedly opens and closes, and generates vibration and noise. . This is understood to be a water hammer phenomenon caused by the water stream hitting the valve port.

Accordingly, an object of the present invention is to provide a device which does not generate vibration and noise when a three-way switching valve using a shape memory alloy spring is operated.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a valve body having one inlet and first and second outlets, and having valves opposed to both outlets at both ends. A bias spring is provided so as to be slidable, and biases the valve body so as to close the first discharge port and open the second discharge port. In the above, a three-way switch using a shape memory alloy spring having a spring constant higher than that of the bias spring and providing a first outlet opening and a second outlet closing above the predetermined temperature is provided. In the valve, a flow path buffer is provided in the first discharge side flow path.

According to the present invention, when the temperature of the fluid is lower than the operating temperature of the shape memory alloy spring, the spring constant of the shape memory alloy spring is small. The water purification port on the water purification side is opened by the power and the discharge port on the drainage side is closed. When the temperature of the fluid becomes higher than the operating temperature of the shape memory alloy spring, the spring constant of the shape memory alloy spring increases. Close the exit. Then, when the temperature of the fluid becomes lower than the operating temperature of the shape memory alloy spring, the spring constant of the shape memory alloy spring is small, so the valve body opens the water purification port on the water purification side by the biasing force of the bias spring, and opens the drain side. Close the outlet. At this time, when the valve body closes the discharge port on the drain side due to the operation of the shape memory alloy, a water hammer phenomenon occurs in the flow path and pulsation occurs, but the flow path provided in the discharge port side flow path on the drain side The pressure fluctuation is buffered by the buffer section, and the water hammer phenomenon is prevented.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which the principle of operation of the three-way switching valve itself is the same as that of the above-described conventional one, but shows a further improvement thereof. That is,
A valve body 2 having a cylindrical valve chamber 1 is provided with a fluid inlet 3 on a side wall thereof, and a first outlet 5 is provided on a first end face 4. The second end face 6 side of the valve body 2 is open. On the other hand, a discharge port member 8 provided with a flange 7 is fixed with a screw 10 with the flange 7 in contact with the end face. An L-shaped drainage channel 11 is formed in the outlet member 8, and an O-ring 12 is provided and a second outlet 14 opened at an end 13 inserted into the valve chamber 1 is provided. A main valve seat 15 is formed around the second discharge port 14. The valve chamber 1 is provided with a valve element 16 that secures a sufficient flow path around the valve element and slides in the axial direction in the cylindrical valve chamber. A first sliding portion 17 and a second sliding portion 18 extend from the disk portions 20 and 21, and the first sliding portion 17 is formed by a first sliding hole 22 formed in the first end face 4 of the valve body 2.
The second sliding portion 18 is slidable in a second sliding hole 23 extending from the second outlet 14 of the outlet member 8. Each of the sliding portions 17 and 18 has a cross-shaped partition 1.
9 so that a sufficient fluid flow path is formed in this portion.

A first seal ring 25 is provided on a base 24 of the first sliding portion 17, and a second seal ring 27 is provided on a base 26 of the second sliding portion 18. Further, the valve body 16
A spring receiver 28 is provided at the center of the spring receiver 2.
A bias spring 30 is contracted between one side surface of the valve 8 and the inner surface on the first end surface 4 side in the valve chamber 1, and the other side surface of the spring receiver 28 and the end surface of the discharge port member 8 inserted into the valve chamber. Between
A shape memory alloy spring 31 is provided.

The spring constant of the shape memory alloy spring 31 is small in a low temperature state.
It has been compressed by the urging force of 0, and the valve element 16 is in the state shown in the figure. When the temperature of the fluid becomes equal to or higher than a predetermined temperature, the fluid enters a shape memory state, and the spring constant increases. A check valve 33 is provided in the connection pipe 32 of the outlet member 8 to allow the flow of fluid from the valve chamber side and to shut off the flow of fluid from the opposite side.

When the above-described three-way switching valve 34 is used as a three-way switching valve in the fluid path shown in FIG. 5, when the water purifier is normally used, tap water is supplied to the four-way valve 5 as described above.
2 through the water purifier main body 55, the valve element 1 of the three-way switching valve
6, the spring constant of the shape memory alloy spring 31 is reduced by the surrounding low temperature as described above, so that the state shown in FIG. 1 is obtained, and the first discharge port 5 of the valve body 2 of the three-way switching valve is formed.
Then, water is supplied as purified water from another flow path in the four-way valve 52.

When the function of the activated carbon is reduced due to long-term use of the water purifier, the water purifier body 5 is used as described above.
By operating the heater provided in 5, the water in the activated carbon is heated to a boiling state (100 ° C.). Since the switching temperature of the three-way switching valve is about 40 ° C., when water of 40 ° C. or more flows, the three-way switching valve switches. At this time, the fluid discharged from the activated carbon is contaminated because the activated carbon has been purified. When this fluid enters the valve chamber from the entrance of the three-way switching valve, the shape memory alloy spring 31 in the valve chamber is set to be in a shape memory state at that temperature, so that the spring constant of the shape memory alloy spring increases. This force moves the valve body to the first discharge port 5 side against the biasing force of the bias spring.

As a result, the first discharge port 5 is closed by the first seal ring 25, and conversely, the second discharge port 14 which has been closed by the second seal ring 27 is opened to purify the activated carbon. The heater in the water purifier main body 55 becomes inactive, the spring constant of the shape memory alloy spring decreases, and the valve body is moved to the second discharge port 5 side by the biasing force of the bias spring. At this time, when the first sliding portion 17 and the second sliding portion 18 provided at both ends of the valve body 16 slide in the first sliding hole 22 and the second sliding hole 23, a frictional force is generated. The rapid movement of the valve body is prevented, and the fluid flow is damped.

Regardless of the effect of the frictional force of the valve body, when the pressure of the water supply line communicating with the water pipe is high and the drainage line is long and the drainage resistance is large, the valve body moves. This may cause a water hammer phenomenon in the pipeline. When such a water hammer phenomenon occurs, the fluid in the pipeline pulsates. However, the flow of fluid from the valve chamber side is allowed in the connection pipe 32 of the discharge port member 8, and the reverse side. Check valve 3 that shuts off the flow of fluid from
Since the valve 3 is fixed, only one-way flow is allowed in the pipeline and the flow of the fluid is buffered, so that the pulsation of the fluid due to the water hammer phenomenon can be prevented. However, it is possible to prevent the generation of noise due to the pulsation, which causes the valve to move left and right in the figure to repeatedly open and close the valve.

2 to 4 show another embodiment of the present invention. In this three-way switching valve, as shown in FIG. 3, the second sliding portion 18 of the three-way switching valve shown in FIG. 1 is extended, and a cylindrical valve 40 having a cruciform partition 19 at the tip is provided. Thus, when the second outlet 14 is closed by the second seal ring 27, the cylindrical valve 40 closes the opening 41 of the second connection pipe 32 of the outlet member 8 with its cylindrical surface. A check valve 33 can be provided in the second connection pipe 32 as in the embodiment of FIG.

In this embodiment, when the first discharge port 5 is closed and the second discharge port 14 is opened as shown in FIG. The alloy spring is actuated to operate the valve body 16 in the same manner as in the previous embodiment.
Moves to the left. At this time, since the cylindrical valve 40 provided on the second sliding portion 18 opens and closes in a direction crossing the opening 41, the seal ring 27 closes sufficiently slower than closing with respect to the valve seat 15. Accordingly, it is possible to prevent a large pressure change from occurring in the fluid pipeline, and it is possible to prevent the occurrence of the water hammer phenomenon as described above. The three-way switching valve moves the valve body 16 by moving the valve body 16.
6 moves to the left, the state shown in FIG. 4 is established, the mode is switched from the drainage mode to the water purification mode, and the fluid from the water purifier main body 55 flows to the water purification side.

Also in this embodiment, as in the embodiment of FIG. 1, the flow of fluid from the valve chamber side is allowed in the connection pipe 32 of the outlet member 8, and the flow of fluid from the opposite side is allowed. By providing the check valve 33 for shutting off, the buffer effect on the fluid is further improved.

[0020]

The present invention is configured as described above.
When operating a three-way switching valve using a shape memory alloy spring, it can prevent sudden pressure fluctuations in the fluid line, prevent the water hammer phenomenon, and prevent the generation of vibration and noise. it can.

By providing the check valve 33 as a flow path buffer, the flow of fluid from the valve chamber side is allowed, the flow of fluid from the opposite side is cut off, and the effect of buffering the fluid is further improved.

In the case where the flow passage buffering portion is formed of a sliding portion having a cross-shaped partition, a frictional force is generated when sliding in the sliding hole, so that the rapid movement of the valve body is prevented and the flow of the fluid is prevented. Produces a buffering effect. As a result, rapid pressure fluctuation in the fluid pipeline can be prevented, and a water hammer phenomenon can be prevented.

[0023] In the case where the flow path buffer section is formed of a cylindrical valve having a cross-shaped partition, the temperature of the water purifier shuts off hot water from the inlet, the shape memory alloy spring operates, and the valve body closes sufficiently slowly. As a result, it is possible to prevent a large pressure change from occurring in the fluid pipeline, and it is possible to prevent the occurrence of a water hammer phenomenon.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a first operation state of another embodiment of the present invention.

FIG. 3 is a partial perspective view of the embodiment.

FIG. 4 is a sectional view showing a second operation state of the embodiment.

FIG. 5 is a configuration diagram of a fluid pipe to which the valve of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve room 2 Valve main body 3 Inlet 4 1st end face 5 1st discharge port 6 2nd end face 7 Flange 8 Drain port member 11 Drainage channel 12 O ring 14 2nd discharge port 15 Main valve seat 16 Valve body 17 1st sliding Part 18 Second sliding part 19 Cross-shaped partition 22 First sliding hole 23 Second sliding hole 25 First seal ring 27 Second seal ring 30 Bias spring 31 Shape memory alloy spring 32 Connection pipe 33 Check valve

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 28, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a valve body having one inlet and first and second outlets, and having valves opposed to both outlets at both ends. A bias spring is provided slidably, and biases the valve body so as to open the first discharge port and close the second discharge port. In the above, a spring made of a shape memory alloy having a spring constant stronger than that of the bias spring is provided.
In a three-way switching valve using a shape memory alloy spring in which a second discharge port is closed and a second discharge port is opened , a flow path buffer is provided in a flow path on the first discharge port side.

Claims (5)

[Claims] 1. A valve body provided with one inlet and first and second discharge ports, slidably provided with a valve element having valves opposed to both discharge ports at both ends, and provided on the valve element. A bias spring that urges the first discharge port to close and opens the second discharge port, and faces the bias spring, and has a spring constant greater than the bias spring at a predetermined temperature or higher than the bias spring. In a three-way switching valve using a shape memory alloy spring in which a first discharge port is opened and a second discharge port is closed when the temperature is equal to or higher than the predetermined temperature, a flow path buffer is provided in the first discharge port side flow path. A three-way switching valve using a shape memory alloy, characterized by having a portion. 2. The three-way switching valve using a shape memory alloy according to claim 1, wherein said flow path buffering part comprises an outlet restricting part provided in a valve body. 3. The three-way switching valve using a shape memory alloy according to claim 1, wherein said flow path buffering part comprises a check valve. 4. The three-way switching valve using a shape memory alloy according to claim 1, wherein said flow path buffering part comprises a sliding part having a cross-shaped partition. 5. The three-way switching valve using a shape memory alloy according to claim 1, wherein said flow path buffering part is a cylindrical valve having a cross-shaped partition.