JP7449576B2 - temperature sensitive valve - Google Patents

Description

The present invention relates to a bimetallic temperature-sensitive valve mainly used as a temperature control trap in a steam passage.

A bimetallic temperature control trap is equipped with a disc bimetal, which is a temperature sensitive body that senses temperature and expands and contracts.By controlling the valve body connected to the shaft in the vertical direction by the expansion and contraction, it is possible to create a valve at any temperature. (For example, Patent Document 1). The temperature control trap of Patent Document 1 has a self-control seated valve mechanism (SCCV mechanism). The SCCV mechanism is a mechanism in which the valve body itself is automatically centered at the valve port without being affected by the inclination of the shaft component by separating the valve body and the shaft component.

Patent No. 6144150

FIG. 3 is a longitudinal sectional view showing a conventional bimetallic temperature-sensitive valve equipped with an SCCV mechanism, and FIG. 4 is an enlarged sectional view showing the SCCV mechanism. In the temperature-sensitive valve shown in FIG. 3, a shaft body 102 is connected to a bimetal 100 that is a driving source, and when the bimetal 100 contracts due to temperature changes, a valve body 104 connected to the shaft body 102 moves up and down.

In the SCCV mechanism shown in FIG. 4, a coil spring 108 is housed in a holder 106 that holds the valve body 104, and after the valve body 104 is seated on the valve port 110, the compressive force of the coil spring 108 is applied to the valve body 104. act. This improves the centering performance of the valve body 104.

However, if the compressive force of the coil spring 108 is too large, centering of the valve body 104 may be hindered. Therefore, the compressive force of the coil spring 108 is such that the valve body 106 is lightly held within the holder 106. Therefore, in the SCCV mechanism, the force that acts in the direction of pressing the valve body 104 against the valve port 110 when the valve is closed is the same as the adsorption force generated by the differential pressure and the weak compressive force caused by the coil spring 108 . Therefore, in the SCCV mechanism, for example, if foreign matter (scale Sc) adheres to the valve port 110, the valve cannot be closed reliably, and steam leakage may occur.

An object of the present invention is to provide a bimetallic temperature-sensitive valve equipped with an SCCV mechanism that can improve the sealing performance of the valve after closing.

In order to achieve the above object, the temperature-sensitive valve of the present invention includes a valve body that opens and closes a valve port, a holder that has a guide hole and holds the valve body in a state that the valve body is inserted into the guide hole, and a a valve stem that is connected to the holder and moves in the axial direction integrally with the holder; a temperature-sensitive driver that drives the holder according to the temperature of the fluid; the valve body, the holder, the valve stem, and the temperature-sensitive drive. a holding spring that is attached to the holder and presses the valve body in a direction that presses the valve body against the peripheral edge of the guide hole of the holder; and a temperature-sensitive deformable member that applies a force in the valve closing direction to the valve body when the temperature of the fluid exceeds a predetermined value. The temperature-sensitive deformable member is, for example, a bimetal.

According to this configuration, after the valve body is seated on the valve port, a force acting in the valve closing direction is applied to the valve body by the temperature-sensitive deformable member. This temperature-sensitive deformable member is set to detect a temperature rise and expand when a steam leak occurs or when drain at a temperature higher than a set temperature is discharged due to a valve closing failure. In this way, the valve body is pressed against the valve port by the expansion of the temperature-sensitive deformable member, which not only increases the sealing force (sealing performance) of the valve, but also crushes foreign matter (scale) attached to the valve port to ensure a reliable seal. A closed state can be obtained.

In the present invention, the holding spring may be a compression coil spring, and the temperature-sensitive deformable member may be disposed inside the compression coil spring. In this case, the temperature-sensitive deformable member may be interposed between the lower end surface of the valve rod and the upper end surface of the valve body. According to this configuration, the temperature-sensitive deformable member can be stored compactly.

According to the temperature-sensitive valve of the present invention, the valve body is pressed against the valve port by the expansion of the temperature-sensitive deformable member, which not only increases the sealing force of the valve but also crushes foreign matter attached to the valve port to ensure reliable closing. Valve status can be obtained.

FIG. 1 is a longitudinal cross-sectional view showing a temperature-sensitive valve according to a first embodiment of the present invention. It is an enlarged sectional view of the temperature-sensitive valve. FIG. 2 is a vertical cross-sectional view showing a conventional temperature-sensitive valve. It is an enlarged sectional view of the temperature-sensitive valve.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a temperature-sensitive valve according to a first embodiment of the present invention. The temperature-sensitive valve 1 shown in FIG. 1 includes a body 2 having an inlet 2a and an outlet 2b for a fluid such as steam on both left and right sides, and a cover 3 that is removably screwed to an opening at the top of the body 2. and a cap 4 that covers the top of the cover 3. A valve chamber 30 is formed by the body 2 and cover 3.

The temperature-sensitive valve 1 further includes a valve seat member 5 screwed to the bottom of the valve chamber 30, a valve body 6 for opening and closing the valve port 5a of the valve seat member 5, and a valve body 6 held at the lower end. A valve rod 10 is connected to the holder 8 and moves integrally with the holder 8 in the axial direction AX. The lower end of the valve stem 10 is inserted into the holder 8 from above. The axial direction AX is set in the vertical direction.

As shown in FIG. 2, a first flange 10a is integrally formed near the lower end of the valve stem 10, and this first flange 10a is engaged with the inner upper end of the holder 8. Specifically, the first flange 10a engages with a groove 8c formed in the holder 8. Thereby, the valve stem 10 is connected to the holder 8 so as to move integrally in the axial direction AX (vertical direction in FIG. 2).

On the other hand, a second flange 6a is provided on the upper part of the valve body 6, and a retaining spring 12 is interposed between the first flange 10a and the second flange 6a. The retaining spring 12 of this embodiment is a compression coil spring. However, the holding spring 12 is not limited to this. A guide hole 8a is formed in the bottom wall 8b of the holder 8, and the valve body 6 is inserted through the guide hole 8a. Specifically, the holding spring 12 presses the second flange 6a of the valve body 6 against the peripheral edge of the guide hole 8a in the bottom wall 8b of the holder 8 (downward), and The valve body 6 is held in a state in which the portion protrudes from the guide hole 8a. At this time, the valve body 6 is supported movably in the vertical and horizontal directions by a guide body 22, which will be described later, and is in a free state.

The upper end of the valve rod 10 shown in FIG. 1 is inserted into an insertion hole 14a provided in the adjustment member 14 so as to be movable up and down. Thereby, the valve stem 10 is supported by the adjustment member 14. The adjustment member 14 is screwed into the screw hole 3a of the cover 3 and fixed with a lock nut 16. A seal between the adjustment member 14 and the cover 3 is provided by an O-ring 15.

A temperature-sensitive driver 18 is attached to the valve stem 10 below the adjustment member 14 . The temperature-sensitive driving body 18 is expandable and deformable in the vertical direction, and drives the holder 8 up and down according to the temperature of the fluid F. Specifically, the temperature-sensitive driver 18 expands when the temperature exceeds a predetermined temperature T1, and contracts when the temperature falls below the predetermined temperature T1. The temperature-sensitive drive body 18 of this embodiment is composed of a bimetal laminate in which a plurality of bimetals are laminated. The upper end of the temperature-sensitive driver 18 is in contact with the lower end surface of the adjustment member 14 . On the other hand, the lower end of the temperature-sensitive driver 18 is in contact with the upper surface of a spring receiving member 20 (described later) fixed to the valve stem 10.

The guide body 22 has a stepped cylindrical shape and is fixed to the valve seat member 5 by welding. The holder 8 is fitted into the inner peripheral surface of the guide body 22 and guided in the vertical direction (axial direction AX) along the guide body 12. Thereby, the holder 8 stably moves in the vertical direction (axial direction AX).

A return spring 24 made of a coil spring is interposed between the spring receiving member 20 and the bottom surface of the valve chamber 30. This return spring 24 applies a spring force to the valve stem 10 in the valve opening direction. Furthermore, a cylindrical screen 26 is arranged in the valve chamber 30. The screen 26 covers the outer circumferences of the temperature-sensitive drive body 18, the holder 8, and the return spring 24. The fluid F flowing in from the inflow port 2a reaches the valve port 5a after foreign substances contained therein are removed by a screen 26.

The bimetal laminate constituting the temperature-sensitive drive body 18 is, for example, stacked as a set of two such that a high-expansion material such as Cu is located on the outside and a low-expansion material such as Ni is located on the inside. It is being A plurality of pairs of these two sheets are fitted into the valve stem 10 in a skewered manner, and the lower end portion of the temperature sensitive drive body 18 is supported on the upper surface of the spring receiving member 20. Since the upper end of the temperature-sensitive driver 18 is in contact with the lower surface of the adjustment member 14, the height position of the temperature-sensor driver 18 can be appropriately adjusted by moving the adjustment member 14 in the vertical direction. You can adjust the spring reaction force.

A through hole 22a is provided in the peripheral wall of the guide body 22 to form a passage for fluid toward the valve port 5a. A plurality of (four in the illustrated example) through holes 22a are provided evenly in the circumferential direction. The through hole 22a is set at a position where it is partially closed by the lowered holder 8 immediately before the valve body 6 closes the valve port 5a. In this embodiment, the guide body 22 and the valve seat member 5 are formed as separate members and joined by welding, but the guide body 22 and the valve seat member 5 are composed of a single integrally formed member. Good too.

The inlet 2a of the fluid F shown in FIG. 1 and the valve chamber 30 communicate with each other via the introduction side communication hole 27. On the other hand, the discharge port 2b of the fluid F and the valve chamber 30 are connected to a valve seat communication passage 28 provided in the valve seat member 5 and extending downward from the valve port 5a, and an outlet side communication hole 29 connected to the valve seat communication passage 28. It communicates through.

As shown in FIG. 2, a temperature-sensitive deformable member 40 is provided inside the cylindrical holder 8. The temperature-sensitive deformable member 40 expands when the temperature of the fluid F exceeds the set temperature T2, and applies a force to the valve body 6 in the valve-closing direction (downward in FIG. 2). In this embodiment, a bimetal laminate in which a plurality of bimetals are stacked is used as the temperature-sensitive deformable member 40. However, the temperature-sensitive deformable member 40 is not limited to bimetal, and may be a shape memory spring, for example.

The temperature-sensitive deformable member 40 of this embodiment is arranged inside the holding spring 12 made of a compression coil spring. That is, the temperature-sensitive deformable member 40 is interposed between the lower end surface of the valve rod 10 and the upper end surface of the valve body 6.

Specifically, a cylindrical rod-shaped shaft member 42 extending upward is connected to the upper end surface of the valve body 6 . The upper end of the shaft member 42 is inserted into an insertion hole 44 provided in the lower end surface of the valve rod 10 so as to be movable up and down. Thereby, the shaft member 42 is supported by the valve rod 10.

The bimetal laminate constituting the temperature-sensitive deformable member 40 is, for example, stacked as a set of two such that a high expansion material such as Cu is located on the outside and a low expansion material such as Ni is located on the inside. It is being A plurality of pairs of these two sheets are fitted into the shaft member 42 in a skewered manner, and the lower end portion of the temperature sensitive deformable member 40 is supported on the upper surface of the valve body 6. The upper end of the temperature-sensitive deformable member 40 is in contact with the lower surface of the valve stem 10.

Next, the operation when the temperature-sensitive valve 1 of this embodiment is used as a steam trap will be explained. When the fluid F is condensate with a temperature lower than the predetermined temperature T1, the expansion force of the temperature-sensitive actuator 18 shown in FIG. Being pushed up. As a result, the valve body 6 held by the holder 8 is separated above the valve port 5a, and the valve port 5a is in an open state, and low-temperature condensate F2 flows outside from the outlet port 2b via the valve port 5a. leak. At this time, the lower end surface of the valve rod 10 and the valve body 6 are separated from each other through a predetermined gap, and this separated state is maintained by the holding spring 12.

Subsequently, when the high-temperature fluid F flows into the valve chamber 30 from the inlet 2a shown in FIG. 1, the valve stem 10 is pushed down by the deformation caused by the expansion of the temperature-sensitive drive body 18. As a result, the holder 8 connected to the valve rod 10 shown in FIG. 2 descends along the inner peripheral surface of the guide body 22 in the valve closing direction. As a result, the valve body 6 held by the holder 8 is attracted by the differential pressure of the fluid F, contacts the valve port 5a, and closes the valve.

At the time when the valve body 6 contacts the valve port 5a, the lower end surface of the valve rod 10 and the valve body 6 remain separated by a predetermined gap. During normal valve closing, low-temperature condensate exists within the valve chamber 30. During this normal valve closing, the valve body 6 is only pressed against the valve port 5a by the differential pressure of the fluid and the spring force of the holding spring 12, so an excessive force acts on the valve port 5a and There is no risk of interfering with centering.

In this way, the valve body 6 is not pressed against the valve port 5a with a strong force, so when the valve is closed, the scale Sc is sandwiched between the valve body 6 and the valve port 5a, and the valve body 6 is pressed against the valve port 5a. It may rise from the surface. In this state, the second flange 6a of the valve body 6 is slightly separated upward from the bottom wall 8b of the holder 8. High-temperature condensate and steam leak from the gap between the valve body 6 and the valve port 5a caused by the scale Sc. As a result, the interiors of the valve chamber 30 and holder 8 are filled with condensate and/or steam and become hot.

Thereby, when the temperature of the fluid F inside the holder 8 exceeds the set temperature T2, the temperature-sensitive deformable member 40 detects the temperature rise and expands. Due to the expansion of the temperature-sensitive deformable member 40, the valve body 6 is pushed down by a maximum amount of the gap between the second flange 6a and the bottom wall 8b, and is pressed against the valve port 5a. Therefore, even if the scale Sc is attached to the valve port 5a, the valve body 6 crushes the scale Sc and comes into close contact with the valve port 5a, thereby achieving a reliable closed valve state.

Further, in this temperature-sensitive valve 1, the valve body 6 is supported in the guide hole 8a of the holder 8 so as to be movable in the vertical and horizontal directions, that is, in a free state. Therefore, when the valve is closed and the valve port 5a receives a suction force, the valve body 6 automatically moves to be concentric with the valve port 5a, and the centering of the valve body 17 is improved. Therefore, the valve body 6 does not hit the valve port 5a unevenly, the valve closing performance is further improved, and steam does not wastefully leak out from the valve port 5a when the valve is closed.

According to the above configuration, after the valve body 6 is seated on the valve port 5a, a force acting in the valve closing direction is applied to the valve body by the temperature-sensitive deformable member 40. The temperature-sensitive deformable member 40 detects a temperature rise and expands when a steam leak occurs or when drain having a temperature higher than the set temperature T2 is discharged due to a valve closing failure. In this way, the valve body 6 is pressed against the valve port 5a by the expansion of the temperature-sensitive deformable member 40, which not only increases the sealing force (sealability) of the valve but also crushes the scale Sc attached to the valve port 5a. A reliable closed state can be obtained.

The temperature-sensitive deformable member 40 is disposed inside the holding spring 12 made of a compression coil spring, and is interposed between the lower end surface of the valve rod 10 and the upper end surface of the valve body 6. According to this configuration, the temperature-sensitive deformable member 40 can be stored compactly within the holder 8.

The present invention is not limited to the above-described embodiments, and various additions, changes, or deletions can be made without departing from the gist of the present invention. Therefore, such materials are also included within the scope of the present invention.

1 Temperature-sensitive valve 2 Body 2a Inlet 2b Outlet 5a Valve port 6 Valve body 8 Holder 8a Guide hole 10 Valve stem 12 Holding spring 18 Temperature-sensitive driver 40 Temperature-sensitive deformable member (bimetal)
F fluid

Claims (4)

A valve body that opens and closes the valve port;
a holder having a guide hole and holding the valve body in a state where the valve body is inserted into the guide hole;
a valve stem connected to the holder and moving in the axial direction integrally with the holder;
a temperature-sensitive drive body that drives the holder according to the temperature of the fluid;
a body that accommodates the valve body, the holder, the valve stem, and the temperature-sensitive driver and has a fluid inlet and an outlet;
a holding spring that is attached to the holder and presses the valve body against the peripheral edge of the guide hole of the holder;
A temperature-sensitive deformable member provided in the holder and applying a force in a valve-closing direction to the valve body when the temperature of the fluid exceeds a predetermined value. The temperature-sensitive valve according to claim 1, wherein the temperature-sensitive deformable member is a bimetal. The temperature-sensitive valve according to claim 1 or 2, wherein the holding spring is a compression coil spring,
A temperature-sensitive valve, wherein the temperature-sensitive deformable member is disposed inside the compression coil spring. 4. The temperature-sensitive valve according to claim 3, wherein the temperature-sensitive deformable member is interposed between a lower end surface of the valve stem and an upper end surface of the valve body.

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