JPH05187573A - Thermosensing reaction valve - Google Patents

Abstract

PURPOSE:To provide a thermosensing reaction valve which can open/close a fluid passage while reponsiveness is kept excellent to the temperature of fluid flowing, in a fluid passage such as the hot water line and the like of a hot water suppller. CONSTITUTION:A valve is equipped with a valve body 3 which is provided on the way of a fluid passage 8 so as to be freely opened/closed, a spring 4 which energizes the valve body 3 to an open position, and a spring 5 which is composed of a shape memory alloy, and energizes the valve body 3 to a close position in opposition to the spring 4. The spring 5 is extended/contracted in response to the temperature of fluid in the fluid passage 8 between an extended position where the valve body 3 is energized to closed position by elastic force greater than the elastic force of the spring 4, and a contracted position where the valve body 3 is energized to opened position by the spring 4 while its elastic force is made smaller than the elastic force of the spring 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve used for a water heater or the like.

[0002]

2. Description of the Related Art For example, a water heater provided with a heat exchanger using a gas burner and a hot water supply passage passing through the heat exchanger is usually provided with a water governor, a water flow switch or the like at a midway point of the hot water supply passage. A detection means is provided, and when water flow is detected by this water flow detection means, in response to this, gas is supplied / ignited to the gas burner to operate the heat exchanger.

In this type of water heater, when the water governor, the water flow switch, or the like malfunctions, the heat exchanger can be used even when there is no water in the hot water supply passage or when there is a very small amount of water. May operate to cause so-called afterglow, and when such an afterglow occurs, water in the hot water supply passage is overheated.

Therefore, in this type of water heater, an overheat prevention device is provided in order to prevent water in the hot water supply passage from being overheated. This overheat prevention device is provided in the hot water supply passage. The operation of the heat exchanger is forcibly stopped when the water becomes extremely hot.

However, in such a water heater,
When an afterglow occurs as described above, even if the operation of the heat exchanger is stopped, high-temperature hot water remains in the hot water supply passage in the heat exchanger, and thus such an afterglow occurs. If water is passed through the hot water supply passage immediately after that, there is a risk that hot water at a temperature not expected by the user will be continuously supplied to the hot water tap in the kitchen, bathroom, or the like.

In this case, in order to prevent such inconvenience, a hot water temperature sensor and a solenoid valve are provided in the hot water supply passage downstream of the heat exchanger, and when the hot water temperature detected by the hot water temperature sensor is high, It is conceivable to close the solenoid valve in response to this.

However, in this method, after the controller of the water heater receives the signal from the hot water sensor,
Since the operation is to close the solenoid valve, a response delay occurs, so the amount of hot water supplied to the kitchen or bathroom is somewhat reduced, but hot water is still supplied to some extent. There is fear.

Therefore, in this type of water heater, there has been a demand for a valve that opens and closes automatically in response to the hot water temperature in the hot water supply passage.

Further, in this type of water heater, since the upstream end of the hot water supply passage has a relatively low incoming water temperature, a resin piping member made of vinyl chloride or the like is inexpensive and easy to handle. Some are connected to a water pipe or the like through.

In such a water heater, when an afterfire occurs as described above, the hot water in the hot water supply passage in the heat exchanger has a high water pressure, so that the hot water is supplied to the hot water supply passage. There is a possibility of sudden reverse flow in the interior to the upstream side, and when such a situation occurs, the resin piping member that connects the hot water supply passage and the water pipe or the like may be damaged by heat.

In order to prevent such inconvenience, a check valve is provided at a location between the heat exchanger of the hot water supply passage and the pipe member made of resin, and this check valve allows the resin made from the heat exchanger side to be provided. It is possible to prevent hot water from flowing back to the piping member side.

[0012] However, in this type of water heater, it is general that the hot water supply passage is drained from the upstream portion of the hot water supply passage through a drain pipe. If a check valve is installed, the drainage inside the hot water supply passage on the downstream side of this check valve cannot be performed, and a new drainage passage is provided on the downstream side of the hot water supply passage so that this drainage can be performed. Forming the water heater complicates the piping configuration of the water heater and increases the size thereof.

For this reason, even in this type of water heater, a valve that is capable of quickly and automatically opening and closing in response to the hot water temperature in the hot water supply passage has been desired.

[0014]

In view of such a background, the present invention opens and closes a fluid passage such as a hot water supply passage of a water heater with good responsiveness according to the temperature of a fluid flowing through the fluid passage. The object is to provide a heat sensitive valve capable of

[0015]

In order to achieve such an object, the thermosensitive valve of the present invention has an openable and closable valve element provided in the middle of a fluid passage and a valve element at a closed position or an open position. A biasing means for biasing and engaging the valve element in the fluid passage,
A spring made of a shape memory alloy for urging the valve body to an open position or a closed position, which is opposite to the urging means, and the spring is configured to move the valve body with an elastic force exceeding the urging force of the urging means. An extended position that urges the valve to the closed position or the open position, and a shortened position in which the elastic force is less than the urging force of the urging means and the valve body is urged to the open position or the closed position by the urging means. It is characterized in that it is configured to be expandable and contractible depending on the fluid temperature in the fluid passage at the position of the valve element.

[0016]

According to the heat-responsive valve of the present invention, the valve body is biased by the biasing means to, for example, the open position, while the valve body is closed by the spring made of the shape memory alloy. Be energized.

At this time, the spring is expanded or shortened in accordance with the temperature of the fluid in the fluid passage. If the spring is expanded, the generated load is increased and the urging force of the urging means is increased. An elastic force exceeding
As a result, the valve body is closed. On the contrary,
When the spring is shortened, its elastic force is lower than the biasing force of the biasing means, and at this time, the biasing force of the biasing means opens the valve element.

Contrary to the above, the valve body is biased to the open position by the biasing means, while it is biased to the open position by the spring made of the shape memory alloy. If it does, the operation is the reverse of the above.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the heat-responsive valve of the present invention is shown in FIG.
A description will be given according to (b). 1A and 1B are vertical cross-sectional views of the thermosensitive valve in an open state and a closed state, respectively.

1 (a) and 1 (b), this heat-responsive valve 1
Is a substantially cylindrical main body 2 in which a substantially cylindrical valve body 3 concentrically inserted therein, a spring 4 for biasing the valve body 3 to an open position, and the valve body 3 are provided. And a spring 5 made of a shape memory alloy that is opened and closed.

The front end portion of the main body portion 2 is closed by a bottom wall portion 2a formed integrally with the outer peripheral side portion thereof, and an inlet side pipe connecting portion 6 is formed at the open rear end portion thereof. Then, at the position near the bottom wall 2a on the outer peripheral side of the main body 2,
An outlet side pipe connecting portion 7 that communicates with the inlet side pipe connecting portion 6 through the inside of the main body portion 2 is formed. These two pipe connecting portions 6 and 7 are connected to the upstream portion and the downstream portion of the fluid passage 8 at an intermediate position.

The valve body 3 is inserted in the main body 2 so as to be movable in the axial direction, and the movement of the valve body 3 causes the interior of the main body 2 to be opened and closed between the two pipe connecting portions 6 and 7. ing.

That is, on the inner peripheral surface of the main body portion 2, the main body portion 2 is provided with a portion between the pipe connection portions 6 and 7 and a portion between the outlet side pipe connection portion 7 and the bottom wall portion 2a. Bottom wall 2a
Slopes 9 and 10 having a diameter gradually decreasing toward the side are formed, and the outer peripheral portion of the rear end portion of the valve body 3 and the outer peripheral portion of the tip end portion of the valve body 3 have the bottom wall portion. As shown in FIG. 1B, the O-rings 11 and 12 are slidably attached to the inclined surfaces 9 and 10 over the entire circumference when the O-rings are moved toward the 2a side. Then, as shown in FIG. 1A, the valve body 3 is moved to the inlet side pipe connecting portion 6 side to move the O-ring 11,
In the state where 12 is separated from the inclined surfaces 9 and 10, respectively,
Gaps 13 and 14 are formed between the rear end and the tip of the valve body 3 and the inner peripheral surface of the main body 2.

Therefore, as shown in FIG. 1 (a), the valve body 3 is moved to the inlet side pipe connecting portion 6 side (hereinafter, referred to as an open position) so that the pipe connecting portions 6 and 7 are separated from each other by a gap 13. Through the valve body 3 or the inside of the valve body 3 and the gap 14, and as shown in FIG. 1B, the O-rings 11 and 12 are moved to the side of the bottom wall portion 2a so that the inclined surfaces 9 and 12, respectively. At a position in which the pipe 10 is slidably contacted (hereinafter, referred to as a closed position), both pipe connecting portions 6 and 7 are shut off via O-rings 11 and 12.

The rear end portion of the valve body 3 and the inlet side pipe connecting portion 6
An annular spring seat 15 is fixed to the inner peripheral surface of the main body 2 at a position between and, and the valve body 3 is moved toward the inlet side pipe connecting portion 6 side by the rear end portion of the valve body 3. The stopper 16 fixed to the spring seat 15 is brought into contact with the spring seat 15 to regulate the spring seat 15.

On the other hand, the spring 4 is interposed between the annular jaw portion 17 formed in the intermediate portion of the inner peripheral surface of the valve body 3 and the bottom wall portion 2a of the main body portion 2, and the valve body 3 is Biasing towards the open position. Further, the spring 5 made of a shape memory alloy is interposed between the annular jaw portion 17 of the valve body 3 and the spring seat 15, and urges the valve body 3 toward the closed position.

In this case, the spring 5 made of a shape memory alloy is made of a shape memory alloy in which the elastic force generated by expansion and contraction changes according to the temperature of the fluid flowing from the inlet side pipe connecting portion 6 in the main body 2. When the temperature of the fluid that comes into contact with it is below a predetermined temperature (for example, below 80 ° C.),
The shortened state produces a relatively small elastic force, and the stretched state produces a relatively large elastic force at a predetermined temperature or higher (for example, 90 ° C. or higher).

As shown in FIG. 1 (a), when the elastic force generated by the spring 5 is small, the elastic force is made sufficiently smaller than the elastic force of the spring 4. In this state Then, the elastic force of the spring 4 becomes larger than the elastic force of the spring 5, and the valve body 3 is moved to the open position by the urging force of the spring 4.

On the contrary, as shown in FIG. 1 (b), when the elastic force generated by the spring 5 is large, the elastic force is made sufficiently larger than that of the spring 4. In this state, the elastic force of the spring 5 becomes larger than the elastic force of the spring 4, and the valve body 3 is moved to the closed position by the urging force of the spring 5.

Therefore, the spring 5 made of a shape memory alloy is adapted to open and close the valve body 3 by changing the shape according to the temperature of the fluid flowing into the main body 2.

Since the inside of the valve body 3 of the thermosensitive valve 1 penetrates, the inlet side pipe connecting portion 6 to the main body portion 2
Depending on the pressure of the fluid flowing into it, it will not move from the open position to the closed position.

Next, the operation of the heat sensitive valve 1 will be described.

In this heat-responsive valve 1, the fluid passage 8
When the temperature of the fluid flowing from the inlet side pipe connecting portion 6 into the main body portion 2 is lower than a predetermined temperature set in advance, for example, 80 ° C. or lower, the spring 5 made of a shape memory alloy is As shown in FIG. 1 (a), the generated elastic force is small (shortened state), and in this case, the valve element 3 is moved to the open position by the urging force of the spring 4 as described above, and therefore the fluid passage The fluid flowing from the upstream portion to the downstream portion of the thermosensitive valve 8 flows in the main body portion 2 of the thermosensitive valve 1 from the inlet side pipe connecting portion 6 to the outlet side pipe connecting portion 7 without any trouble.

On the other hand, when the temperature of the fluid flowing from the inlet side pipe connecting portion 6 into the main body portion 2 becomes a certain predetermined temperature or higher, for example, 90 ° C. or higher, the spring 5 made of a shape memory alloy is As shown in FIG. 1 (b),
The direct contact with the fluid immediately brings about a large elastic force generation state (extended state), and in this case, the valve body 3 is moved to the closed position by the urging force of the spring 5 as described above. Then, in this state, the fluid passage 8 is blocked at the position of the heat sensitive valve 1, and the fluid is prevented from passing through the heat sensitive valve 1.

In this case, since the spring 5 made of a shape memory alloy is always provided at a location communicating with the upstream side of the fluid passage 8 through the inlet side pipe connecting portion 6, the elastic force generated by the spring 5 is generated. Is maintained until the fluid temperature on the upstream side of the fluid passage 8 decreases, and therefore the valve body 3
Are maintained in the closed position.

Next, another example of the thermosensitive valve of the present invention is shown in FIG.
A description will be given according to (a) and (b). 2 (a), (b)
[Fig. 3] is a vertical sectional view of the thermoresponsive valve in an open state and a closed state, respectively.

The heat-responsive valve 18 has a substantially cylindrical main body 19 and a substantially cylindrical valve body 20 with one end closed.
A spring 21 which is an urging means for urging the valve body 20 to the open position, and a spring 22 made of a shape memory alloy for driving the valve body 20 to open and close according to the temperature of the water flow.

In this case, an inlet side pipe connecting portion 23 and an outlet side pipe connecting portion 24 are formed at both open ends of the main body portion 19, and these pipe connecting portions 23, 24 are formed.
Is connected to an upstream portion and a downstream portion of the fluid passage 25 at an intermediate position. The inner peripheral surface portion of the main body portion 19 has a small-diameter inner peripheral portion 19a formed on the inlet-side pipe connecting portion 23 side and an outlet-side pipe connecting portion 24 from the small-diameter inner peripheral portion 19a through an inner peripheral step portion 19b. And a large-diameter inner peripheral portion 19c formed on the side.

The valve body 20 has a large-diameter inner peripheral portion 19 of the main body portion 19.
It is inserted in the inside of c so as to be movable in the axial direction, and the inside of the main body portion 19 is opened and closed by the movement.

That is, the inlet side pipe connecting portion 2 of the valve body 20
The end portion on the third side is closed by a bottom wall portion 26 formed integrally with the outer peripheral side portion of the valve body 20, and the bottom wall portion 26 has a larger diameter than the small diameter inner peripheral portion 19a of the main body portion 19. Has been formed. Then, the peripheral edge portion of the end surface portion of the bottom wall portion 26 on the small diameter inner peripheral portion 19a side contacts the inner peripheral stepped portion 19b of the main body portion 19 when the valve body 20 is moved to the small diameter inner peripheral portion 19a side. An annular packing 27 that is in contact is fixed. Also, the valve body 2
The open end portion 28 of 0 is slidably contacted with the large-diameter inner peripheral portion 19c of the main body portion 19 over the entire circumference, and a plurality of fluid passage holes 29 are formed in the outer peripheral side portion of the valve body 20.

Therefore, as shown in FIG. 2A, the valve body 20 is moved to the outlet side pipe connecting portion 24 side and the bottom wall portion 26 is moved.
Is separated from the inner peripheral stepped portion 19b of the main body portion 19 (hereinafter, referred to as an open position), the inlet side pipe connecting portion 23 is provided inside the small diameter inner peripheral portion 19a of the main body portion 19 and the fluid passage hole 29 of the valve body 20. And, it communicates with the outlet side pipe connecting portion 24 through the large-diameter inner peripheral portion 19c of the main body portion 19, and, as shown in FIG. 2B, is moved to the inlet side pipe connecting portion 23 side to move to the bottom wall portion. Two
At a position where 6 is pressed against the inner peripheral stepped portion 19b via the annular packing 27 (hereinafter, referred to as a closed position), both pipe connecting portions 23 and 24 are shut off via the bottom wall portion 26 and the annular packing 27.

A plurality of fluid passage holes 30 are formed in the large-diameter inner peripheral portion 19c of the main body portion 19 at a position between the open end portion 28 of the valve body 20 and the outlet side pipe connecting portion 24. The annular spring seat 31 is fixed, and the valve body 20 is moved toward the outlet side pipe connecting portion 24 side by the opening end portion 2 of the valve body 20.
8 is regulated by abutting on the spring seat 31.

On the other hand, the spring 21 is interposed between the open end portion 28 of the valve body 20 and the inner peripheral stepped portion 19b of the main body portion 19 and biases the valve body 20 to the open position. Also,
The spring 22 made of a shape memory alloy is interposed between the bottom wall portion 26 of the valve body 20 and the spring seat 31, and urges the valve body 20 toward the closed position.

In this case, the spring 22 made of a shape memory alloy is made of a shape memory alloy in which the elastic force generated changes according to the temperature of the fluid at the position of the outlet side pipe connecting portion 24 in the main body portion 19. When the temperature of the fluid to be contacted is below a predetermined temperature (for example, below 80 ° C), it is in a shortened state in which a relatively small elastic force is generated, and when it is above a predetermined temperature (for example, above 90 ° C). Is in an expanded state that produces a relatively large elastic force.

Then, as shown in FIG. 2A, when the elastic force generated by the spring 22 is small, the elastic force is made sufficiently smaller than the elastic force of the spring 21. Then, the elastic force of the spring 21 becomes larger than the elastic force of the spring 22, and the valve body 20 is moved to the open position by the urging force of the spring 21.

On the contrary, as shown in FIG. 2B, when the elastic force generated by the spring 22 is large, the elastic force is made sufficiently larger than that of the spring 21, In this state, the elastic force of the spring 22 becomes larger than the elastic force of the spring 21,
The valve body 20 is moved to the closed position by the urging force of the spring 22.

Therefore, the spring 22 made of a shape memory alloy is configured to open and close the valve body 20 by changing the shape at the position of the outlet side pipe connecting portion 24 of the main body portion 19 according to the temperature of the fluid.

Next, the operation of the heat sensitive valve 18 will be described.

In the thermosensitive valve 18, when the temperature of the fluid flowing in the fluid passage 25 from the inlet side pipe connecting portion 23 into the main body portion 19 is below a predetermined temperature set in advance, for example, 80 ° C. In the following cases, the spring 22 made of the shape memory alloy is, as shown in FIG.
The generated elastic force is small (shortened state), and in this case, the valve body 20 is moved to the open position by the urging force of the spring 21 as described above, and therefore the fluid passage 25 is moved from the upstream portion to the downstream portion. The flowing fluid flows inside the main body 19 from the inlet side pipe connecting portion 23 to the outlet side pipe connecting portion 24.
It flows without trouble.

On the other hand, for some reason, for example, the temperature of the fluid in the fluid passage 25 on the downstream side of the heat-responsive valve 18 is sufficiently higher than that on the upstream side of the fluid passage 25 (for example, 9
0 ° C. or higher), the high temperature fluid may try to flow backward from the downstream side of the fluid passage 25 through the heat sensitive valve 18 to the upstream side due to the increase in the pressure. In such a case, As shown in FIG. 2 (b), the spring 22 made of a shape memory alloy immediately generates elasticity due to direct contact with the high temperature fluid which flows backward from the outlet side pipe connecting portion 24 into the main body portion 19. High force (extended state)
As a result, the valve body 20 is moved to the closed position by the biasing force of the spring 22, as described above. And
In this state, the fluid passage 25 is blocked at the position of the heat-responsive valve 18, and the fluid flows backward through the heat-responsive valve 18 and the fluid passage 2
Attempts to flow upstream of 5 are blocked.

In this case, the spring 22 made of the shape memory alloy is connected to the fluid passage 25 through the outlet side pipe connecting portion 24.
Since it is always installed on the upstream side of the
The state in which the elastic force generated by the spring 22 is large is maintained until the fluid temperature on the downstream side of the fluid passage 25 decreases, and therefore the valve body 20 is maintained in the closed position.

Next, the heat-responsive valves 1 and 18 described above
An embodiment in which is applied to a water heater will be described with reference to FIG. FIG. 3 is an explanatory configuration diagram of this water heater.

In FIG. 3, the water heater 32 has a heat exchanger 3 having a gas burner 35 in the body case 33 to which gas is supplied from a gas pipe (not shown) through a gas passage 34.
6 and a hot water supply passage 37 which is a fluid passage corresponding to the fluid passages 8 and 25 (see FIGS. 1 and 2). The middle portion of the hot water supply passage 37 is wound around the main body portion 38 of the heat exchanger 36. Has been done. The heat-responsive valves 1 and 18 are provided in the hot-water supply passage 37 at a location downstream of the heat exchanger 36 and a location upstream of the heat exchanger 36, respectively (see FIGS. 1 and 2). ..

In this case, the hot water supply passage 37 is connected, for example, to a water pipe (not shown) at its upstream end via a resin pipe 39 made of vinyl chloride or the like, and its downstream end is provided with a hot water tap 40 ,. Water which is connected to the hot water supply faucet 42 and the shower head 43 through 41 and is introduced through the resin pipe 39, a water flow detection mechanism 44, a water amount regulator 45,
The heat sensitive valve 18, the overpressure relief valve 46, the heat exchanger 36, and the heat sensitive valve 1 are sequentially supplied to the faucet 42 and the shower head 43.

The upstream end of the gas passage 34 is connected to a gas pipe (not shown) outside the main body case 33. From this gas pipe, a safety gas valve 47, a gas amount adjusting mechanism 48, a gas valve 49, a gas governor 50 and Gas is supplied to the gas burner 35 through the gas nozzle 51 in order. When the gas is supplied to the gas burner 35, the heat exchanger 36 supplies this gas to the gas burner 3
5, the water in the hot water supply passage 37 is appropriately heated through the main body 38, whereby hot water can be supplied from the hot water supply passage 37 to the faucet 42 and the shower head 43.

The water passage detection mechanism 44 of the hot water supply passage 37 has a well-known water governor 52 and a diaphragm 53. As is well known, water passage in the hot water supply passage 37 is detected by the water pressure received by the diaphragm 53. In response to this, the gas valve 49 of the gas passage 34 is moved to the water governor 52.
I'm trying to open through.

Next, the operation of the water heater 32 will be described.

In FIG. 3, in the water heater 32, when one of the hot water taps 40 and 41 is opened, water can flow from the resin pipe 39 to the faucet 42 or the shower head 43 through the hot water supply passage 37. Done.

At this time, the water passage detection mechanism 44 of the hot water supply passage 37 detects the passage of water through the hot water supply passage 37, and in response to this, the gas valve 49 of the gas passage 34 is opened. Then, when the gas valve 49 is opened, as described above, the gas passage 3
Gas is supplied to the gas burner 35 of the heat exchanger 36 via 4 and combustion of this gas is performed, whereby the water flow in the hot water supply passage 37 is heated via the main body 38 of the heat exchanger 36. It By this heating, hot water is supplied to the faucet 42 or the shower head 43.

In this case, the operation of the heat exchanger 36 is appropriately controlled by a controller (not shown) so that the hot water supply temperature is normally a normal temperature of 40 to 50 ° C., for example.

At such a normal hot water supply temperature, as shown in FIGS. 1 (a) and 2 (a), the springs 5 and 22 made of a shape memory alloy of the heat-responsive valves 1 and 18 are not provided. The generated elastic force is in a small state. Therefore, as described above, the valve elements 3 of the heat-responsive valves 1 and 18 are
20 has been moved to the open position.

On the other hand, in such a water heater 32, when the water governor 52 or the diaphragm 53 of the water flow detecting mechanism 44 malfunctions or the like, for example, there is no water in the hot water supply passage 37, but there is no gas passage. The gas valve 49 of 34 may open and the heat exchanger 36 may temporarily operate, causing a so-called afterglow. In this case, the operation of the heat exchanger 36 is stopped by an overheat prevention device (not shown). However, the water in the hot water supply passage 37 may be heated to a high temperature by the afterglow at the location of the heat exchanger 36 and its pressure may become high. In this case, the pressure in the hot water supply passage 37 is, for example, 1 due to the overpressure relief valve 46 in the hot water supply passage 37.
Although it is set so as not to exceed 7.5 kgf / cm ^2, the boiling point of water also rises at such a high pressure, and the water in the hot water supply passage 37 at the heat exchanger 36 is, for example, 150 May be heated to ~ 180 ° C.

In this way, with the water in the hot water supply passage 37 being heated to a high temperature at the heat exchanger 36,
When the hot water taps 40 and 41 are opened, the high-temperature hot water tends to flow toward the hot water taps 40 and 41 through the heat sensitive valve 1.

However, as shown in FIG. 1 (a), at this time, in the hot water supply passage 37, there is a high temperature inside the main body 2 from the heat exchanger 35 side through the inlet side pipe connecting portion 6 of the heat sensitive valve 1. When the hot water flows in, the hot water directly contacts the spring 5 made of the shape memory alloy of the heat-responsive valve 1, so that the spring 5 immediately generates a large elastic force as shown in FIG. 1 (b). Then, the valve body 3 is moved to the closed position, whereby the outlet side pipe connecting portion 7 of the heat-responsive valve 1 is
Is cut off from the inlet side pipe connecting portion 6 side as described above.

Therefore, the hot water flowing into the main body 2 from the heat exchanger 36 side of the hot water supply passage 37 does not flow out to the downstream side of the heat-responsive valve 1, whereby the hot water flows into the faucet 42. And is supplied to the shower head 43.

In this case, the spring 5 made of a shape memory alloy is connected to the hot water supply passage 3 via the inlet side pipe connecting portion 6.
7 is provided on the upstream side of the heat exchanger 36, that is, on the side where the heat exchanger 36 is always in communication. Therefore, as described above, the closed state of the heat-responsive valve 1 is the hot water supply passage 3 at the place of the heat exchanger 36.
It is maintained until the hot water temperature of 7 decreases.

2 and 3, when the afterfire of the heat exchanger 36 occurs as described above, the temperature of the water in the hot water supply passage 37 at the heat exchanger 36 becomes high as described above. Since it becomes high pressure, this high temperature and high pressure hot water
There is a risk that the pipe 39 will be damaged by the hot water when an attempt is made to flow back to the upstream side of the hot water supply passage 37, that is, to the resin pipe 39 side via the heat sensitive valve 18, and such a backflow occurs.

At this time, however, as shown in FIG. 2 (b), the spring 22 made of the shape-memory alloy of the heat-responsive valve 18 tries to flow backward from the outlet-side pipe connection 24 into the main body 19 at high temperature. Upon contact with the valve body 20, the generated elastic force immediately becomes large, and the valve body 20 is moved to the closed position. As a result, high temperature hot water flows from the heat exchanger 36 of the hot water supply passage 37 to the upstream side of the heat sensitive valve 18. Is prevented from flowing backwards.
Further, in this case, since the high-temperature hot water that is about to flow backward from the outlet side pipe connecting portion 24 into the main body portion 19 has a high pressure, the pressure acts on the bottom wall portion 26 of the valve body 20 to cause the valve The movement of the body 20 to the closed position is promoted.

Therefore, high-temperature hot water flows through the hot water supply passage 37 through the pipe 3
There is no reverse flow up to 9 and the pipe 39 is not damaged by hot water.

In this case, the spring 22 made of the shape memory alloy is provided at a location which is always in communication with the hot water supply passage 37 at the location of the heat exchanger 36 via the outlet side pipe connecting portion 24. As described above, the closed state of the heat-responsive valve 18 is maintained until the hot water temperature in the heat exchanger 36 of the hot water supply passage 37 decreases.

As described above, in the water heater 32, the hot water supply passages 37 are provided with the heat-responsive valves 1 and 18, so that when the afterheat of the heat exchanger 36 occurs, the hot water is supplied to the faucet 42. The heat-sensitive valve 1 quickly prevents the heat-sensitive valve 1 from being supplied to the shower head 43, and the heat-sensitive valve 18 quickly prevents the hot and high-pressure hot water from flowing back into the resin pipe 39.

In the embodiment described above, the springs 5 and 22 of the heat-responsive valves 1 and 18 are made of a shape memory alloy, but conversely, the springs 4 and 21 are made of a shape memory alloy. Of course, it is also possible to perform the same operation as the example.

Further, the heat-responsive valves 1 and 18 can be applied not only to the water heater 32 as in this embodiment, but
It can also be applied to various fluid passages that need to be opened and closed quickly according to the temperature of the fluid.Furthermore, the fluid passage is normally closed and the fluid passage is opened when the temperature of the fluid exceeds a predetermined temperature. Of course, it is also possible to configure the heat-responsive valve to open the.

[0074]

As is apparent from the above description, according to the thermosensitive valve of the present invention, the openable and closable valve element provided in the middle of the fluid passage is biased to the closed position or the open position by the biasing means. On the other hand, a spring made of a shape memory alloy is urged in the direction opposite to the urging means, and at this time, the spring is expanded and contracted according to the fluid temperature of the fluid passage to open and close the valve element, thereby It is possible to quickly open and close the fluid passage according to the temperature of the fluid flowing through the passage, and it is possible to provide an on-off valve having excellent responsiveness to temperature.

[Brief description of drawings]

FIG. 1 (a) is a longitudinal sectional view of an example of a thermosensitive valve of the present invention in an open state, and FIG. 1 (b) is a longitudinal sectional view of the thermosensitive valve in a closed state.

FIG. 2A is a longitudinal sectional view of another example of the thermoresponsive valve of the present invention in an open state, and FIG. 2B is a longitudinal sectional view of the thermoresponsive valve in a closed state.

FIG. 3 is an explanatory configuration diagram of a water heater to which the heat-responsive valve of the present invention is applied.

[Explanation of symbols]

1, 18 ... Thermosensitive valve, 3, 20 ... Valve body, 4, 21 ... Energizing means (spring), 5, 22 ... Spring made of shape memory alloy, 8, 25 ... Fluid passage.

Claims (1)

[Claims] 1. A valve body provided in the middle of a fluid passage, which can be opened and closed, an urging means for urging the valve body to a closed position or an open position, and the valve body engaged in the fluid passage. A spring made of a shape memory alloy for urging the valve body to an open position or a closed position in reverse of the urging means, the spring having an elastic force exceeding the urging force of the urging means. An extended position for urging the valve body to the closed position or the open position, and a shortened position where the elastic force is less than the urging force of the urging means to urge the valve element to the open position or the closed position by the urging means. A heat-responsive valve characterized by being configured to be expandable / contractible depending on the fluid temperature in the fluid passage at the position of the valve body.