JPH0446155Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field The present invention utilizes thermal deformation of a thermally responsive element such as a bimetal, thermowax, or shape memory alloy to close a valve and automatically discharge fluid below a predetermined temperature. The present invention relates to a responsive valve, and particularly to a means for absorbing an abnormal increase in internal stress generated in a thermally responsive element due to heating after the valve is closed.

The present invention is used in the field of flow rate control based on fluid temperature, particularly in the field of control for automatically discharging fluid below a predetermined temperature from a steam or hot water system to the outside of the system.

Technical Background In a temperature-responsive valve that uses the thermal deformation force of a thermally-responsive element as the valve-closing force, if the thermally-responsive element is further heated after the valve is closed, the internal stress of the thermally-responsive element will increase and the performance will deteriorate. It deteriorates and cannot open and close normally.

In particular, in shape memory alloys, when internal stress increases, deformation strain increases, and this strain cannot be completely recovered, resulting in significant performance deterioration.

Prior Art and Its Problems Therefore, the increase in internal stress of a thermally responsive element has been conventionally absorbed by a spring.

An example of this is shown in Japanese Utility Model Publication No. 44-27335. This has a spring interposed between each pair of bimetals, and even if the bimetal is further heated after the valve is closed, the spring can be compressed and deformed to absorb an increase in the internal stress of the bimetal.

In this case, when the bimetal is thermally deformed and displaces the valve body from the open position to the closed position, the bimetal always compresses and deforms the elastic body while displacing the valve body, so the valve opening of the valve body is closed. There is a problem that the sealing force is small when doing so. That is, this is because the deformation force of the bimetal is dispersed into the sealing force and the force compressing the elastic body.

Means for Solving the Problems The technical means of the present invention taken to solve the above problems is that the valve casing has an inlet, a valve chamber into which the fluid in the inlet flows, and a valve chamber in which the fluid in the valve chamber is connected to the valve opening. A valve stem with a smaller diameter than the valve opening is arranged to pass through the valve opening, and a valve body that opens and closes the valve opening from the outlet side is formed at the outlet side end of the valve stem. A spring receiver is arranged around the outer circumference of the part located in the valve chamber so that it can be raised and lowered, and a stopper part is provided on the valve stem to prohibit displacement of the spring receiver from the stopper part to the valve port side.
A thermally responsive element is placed between the fixed wall on the valve port side and the spring holder, and a spring is placed between the end of the valve stem on the opposite side of the valve port and the spring holder, so that the valve closing force of the thermally responsive element is slightly lower than the valve closing force of the thermally responsive element when the valve is closed. It is compressed and arranged so that it has a large force.

Effect The operation of the above technical means is as follows.

The thermally responsive element deforms in accordance with the rise in fluid temperature within the valve chamber, and accordingly displaces the valve stem, causing the valve body to approach the valve port and close the valve port. At this time, the spring has a force slightly larger than the valve closing force of the thermally responsive element, so it is not compressively deformed. When the temperature inside the valve chamber further increases after the valve is closed, the deforming force of the thermally responsive element becomes greater than the force of the spring, and the thermally responsive element further deforms while compressing the spring. The thermally responsive element does not compress the spring until the thermally responsive element displaces the valve body to the valve closing position, so all the deformation force of the thermally responsive element can be used as a sealing force to close the valve opening of the valve body, ensuring reliable The valve port can be kept closed.

Effect of invention The present invention produces the following specific effects.

Since the spring is arranged so as to be compressed so as to have a force slightly larger than the valve closing force of the thermally responsive element when the valve is closed, the length of the spring can be made smaller than that of the conventional one. Therefore, the entire temperature-responsive valve can be made compact.

As shown in Utility Model Application No. 54-12131,
Even if a spring is arranged to bias the valve seat member in the direction opposite to the valve body so that the valve seat member can slide, the spring can be compressed only after the valve is closed, but in this case, A means for airtightly sealing the sliding surface between the valve casing and the valve seat member is required, resulting in a complicated structure, and fluid may leak from the sliding surface due to wear of the sealing material. The present invention does not require such sealing means and does not complicate the structure.

In addition, in the above-mentioned publication, after the valve is closed, the fluid pressure acts not on the valve opening area but on the entire valve seat member, and the load acting on the temperature-responsive element becomes large. Even after this, the fluid pressure only acts on the valve opening area, and the internal stress generated in the thermally responsive element is small.

DESCRIPTION OF EMBODIMENTS An example (see drawings) showing a specific example of the above technical means will be described.

A valve chamber 4 is formed by screwing a lid 2 onto a substantially bowl-shaped main body 1 via a gasket 3. Main body 1 has entrance 5
and form an outlet 6. A valve seat member 7 is provided at the bottom of the valve chamber 4.
are screwed in through the gasket 8. The valve seat member 7 has a valve stem hole 9 at the axis and a conical hole portion 10 from the valve stem hole 9.
A valve opening 11 is formed which widens through the opening. valve mouth 11
communicates with the outlet 6, and the conical slope of the conical hole portion 10 serves as a valve seat. A plurality of through holes 12 are formed in the valve seat member 7 to reach the valve shaft hole 9. A shoulder part is formed on the lower inner wall of the main body 1, and a cap-shaped screen 13 whose outer periphery is lightly fitted is arranged.

A valve rod 14 is placed through the valve shaft hole 9 and the valve port 11. A hemispherical valve body 15 is attached to the end of the valve stem 14 on the side of the valve port 11.
Attach tightly. A portion of the valve stem 14 located in the valve chamber 4 is formed to have an expanded diameter, and a stepped portion is formed at the upper portion thereof. Spring receivers 1 are provided at the tip and stepped portion of the valve stem 14, respectively.
6 and 17, and a spring 18 is placed between them in a compressed state. The spring receiver 16 is fixed with a nut 19. A shape memory alloy 20 is placed between the spring receiver 17 and the valve seat member 7.

The distance between the spring receivers 16 and 17 is designed so that the force of the spring 18 is slightly larger than the valve closing force of the shape memory alloy 20 when the valve is closed.

The shape memory alloy used is a titanium-nickel alloy, a copper-aluminum-nickel alloy, or the like, which transforms into a matrix when heated and the temperature changes, and deforms into an elongated shape memorized in the matrix in advance.

The operation of the temperature-responsive valve described above is as follows. When the temperature of the fluid flowing into the valve chamber 4 is low, the shape memory alloy 20 is contracted, and the valve body is moved away from the valve port by the fluid pressure and its own weight and is in the valve open position. The fluid enters the valve chamber 4 from the inlet 5 through the strainer 13 and flows out to the outlet 6 through the valve shaft hole 9, the through hole 12, and the valve port 11.

When the temperature of the fluid flowing into the valve chamber 4 increases, the shape memory alloy 20 expands and displaces the valve stem 14.
The valve body 15 is moved toward the valve port 11 to close the valve port 11 and close the valve.

If the shape memory alloy 20 is further heated after the valve is closed, it will further expand while compressing the spring 18, thereby absorbing the increase in internal stress.

When the fluid temperature decreases, the shape memory alloy 20
The valve contracts and opens due to fluid pressure.

In the above embodiments, a shape memory alloy having a unidirectional shape memory effect was used, but a bidirectional shape memory alloy having a shape memory effect in both the matrix phase and the martensitic phase may be used.

[Brief explanation of the drawing]

The figure is a sectional view of a temperature-responsive valve according to the present invention. 7... Valve seat member, 11... Valve port, 14... Valve stem, 15... Valve body, 18... Spring, 20... Shape memory alloy.

Claims (1)

[Scope of utility model registration request] The valve casing forms an inlet, a valve chamber into which fluid from the inlet flows, and an outlet from which fluid from the valve chamber flows out through the valve port, and a valve stem passing through the valve port and having a smaller diameter than the valve port is arranged; A valve body that opens and closes the valve port from the outlet side is formed at the outlet end of the valve stem, a spring receiver is arranged around the outer circumference of the part of the valve stem located inside the valve chamber, and a stopper part is provided on the valve stem. In order to prevent displacement of the spring receiver from the stopper part toward the valve port side, a thermally responsive element is placed between the fixed wall on the valve port side and the spring receiver, and a thermally responsive element is placed between the end of the valve stem opposite to the valve port side and the spring receiver. A temperature-responsive valve in which a spring is compressed and arranged to have a force slightly larger than the valve-closing force of the thermally-responsive element when the valve is closed.