JP7811412B2 - valve - Google Patents

Description

This invention relates to a fluid control valve, and in particular to a valve that is suitable for use as an opening/closing valve for controlling high-pressure fluid.

The valve for high-pressure fluid described in Patent Document 1, shown in Figure 5 (1), includes a valve body 101 having a valve chamber 104 that communicates with a fluid inlet 102 and a fluid outlet 103. A seat member 106 is disposed within the valve chamber 104 and has a valve seat 107 formed therein that controls the fluid by contacting and separating from a valve element 114. The seat member 106 is pressed upward from below by a retaining member 109 that is threadedly engaged with the valve body 101. Fluid leakage from the upper end of the seat member 106 is prevented.

Fig. 5(2) is a partially enlarged view of Fig. 5(1), and some of the parts described in Fig. 5(1) will not be described again.
The fluid flows from the fluid inlet 102 through the inlet passage 102 a , passes through the inlet-side communication passage 106 a and the outlet-side communication passage 106 b formed in the sheet member 106 , and flows out of the fluid outlet 103 through the outlet passage 103 a.

International Publication No. WO2019/026814

However, if the pressure of the fluid flowing inside the valve is further increased, or if the fluid temperature is high and high pressure, there is a concern that the screws may loosen, reducing the surface pressure between the seat member and the valve body and causing fluid leakage from the seat member abutment surface.

The object of the present invention was made in consideration of these points, and its purpose is to provide a valve that is less likely to leak between the seat member and the valve body when high-temperature, high-pressure fluids are flowing through it.

The present invention (1), which was made to solve the above problems, is a valve comprising a valve body having a valve chamber communicating with an inlet passage and an outlet passage for a fluid, an inlet-side communicating passage communicating with the inlet passage, an outlet-side communicating passage communicating with the outlet passage, and a valve seat formed on the periphery of the opening of the outlet-side communicating passage, a cylindrical seat member disposed in the valve chamber, and a valve body that can abut against and separate from the valve seat, wherein a male taper is formed on the valve seat side end of the seat member, and the male taper presses against a female taper formed in the valve chamber to form a seal.

In invention (1), the seat member has a tapered male taper on the outer periphery toward the valve seat. A female taper that tapers to this male taper is formed in the valve chamber. This taper fit between the seat member and the valve body ensures a tapered fit. Even if a force acts on the seat member to reduce the engagement force, friction acts on the tapered slope, and the force reducing the engagement force decreases as the sine of the taper angle. This makes it less likely that the seal between the seat member and the valve body will deteriorate. More details are provided in the explanatory section of Figure 4.

The present invention (2) is a valve according to the present invention (1), characterized in that the pressing force is generated by threading a female thread engraved on the inner surface of the valve chamber with a male thread engraved on the outer surface of the seat member.

In the present invention (2), the pressing force is generated by a simple structure in which a female thread engraved on the inner surface of the valve chamber is threadedly engaged with a male thread engraved on the outer surface of the seat member, thereby reducing costs.

The present invention (3) is a valve of the present invention (1), characterized in that the pressing force is generated by a seat member holder arranged below the seat member.

In present invention (3), even when the seat member and the valve body are not screwed together as in present invention (2), sealing properties can be maintained by applying pressure to the seat member using a seat member holder.

The present invention (4) is a valve according to the present invention (3), characterized in that a seat retainer male screw is formed on the outer periphery of the seat retainer, and the seat retainer male screw and the female screw are threaded together to generate the pressing force.

In the present invention (4), the pressing force is generated by a simple structure in which the male seat retainer thread formed on the outer periphery of the seat retainer is threadedly engaged with the female thread engraved on the valve body, thereby reducing costs.

The present invention makes it possible to provide a valve that is less likely to leak between the seat member and the valve body when high-temperature, high-pressure fluids are flowing through it.

1 is a partial cross-sectional view showing the entire valve according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view showing a part of the valve shown in FIG. FIG. 10A and 10B are schematic diagrams illustrating the state of force application, etc., comparing a conventional sheet member with the sheet member of the present invention. FIG. 1 is a partial cross-sectional view showing the entire conventional valve.

Embodiments of the present invention will now be described in detail with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

Figure 1 shows a partial cross-sectional overall view of a valve according to an embodiment of the present invention. Valve 1 controls the flow of fluid by contacting and separating a valve element 4 attached to the tip of a stem 3 connected to an actuator 2 and a seat member 30 formed with a valve seat 31. The seat member 30 is disposed inside a valve body 10, which has an inlet passage 11 and an outlet passage 12. The seat member 30 is required to maintain airtightness, be wear-resistant, thermally conductive, and strong, and may be made of ordinary carbon or metal.
A tapered eccentric screw 40 and a cover member 21 and a plug 20 for sealing with a gasket 22 are disposed below the seat member 30, and the actuator 2 and the valve body 10 are joined by a fixing screw 5.

Figure 2 is an enlarged view of the main parts of the valve in Figure 1. Some of the parts common to Figure 1 will not be described. A valve chamber 13 is formed inside the valve body 10, and a cylindrical seat member 30 is disposed inside the valve chamber 13. The valve chamber 13 has a large-diameter portion 13a and a small-diameter portion 13b. The large-diameter portion 13a communicates with the inlet passage 11 through an opening formed in its inner circumferential surface, and communicates with the outlet passage 12 through an opening formed in its ceiling surface. The small-diameter portion 13b has a female thread 14 formed on its inner circumferential surface, and opens to the bottom surface of the valve body 10. The seat member 30 is inserted from the bottom of the valve body 10, and a male thread 34 engraved on the lower outer periphery of the seat member 30 threads into the female thread 14 to secure it in place, and a male taper 35 formed on the upper end surface of the seat member is pressed against a female taper 16 formed on the ceiling surface of the large diameter portion 13a to form a seal. A tapered eccentric screw 40 is disposed below the seat member 30 and threadedly engages with the female thread 14, preventing it from loosening. An annular gasket 22, cover member 21, and plug 20 are disposed below the tapered eccentric screw 40, and a seal is formed between the gasket 22 and the valve body 10 to prevent fluid from leaking out from the bottom of the valve body 10.
The seat member 30 has an inlet-side communicating passage 32 that opens on the outer peripheral surface of the seat member 30 and communicates with the inlet passage 11, and an outlet-side communicating passage 33 that opens at the upper end of the seat member 30 and communicates with the outlet passage 12. A valve seat 31 is formed around the periphery of the opening of the outlet-side communicating passage 33. In the embodiment shown in Figure 2, the inlet-side communicating passage 32 has an oval shape that is long in the axial direction, and is formed in a total of four places: two that open on the left and right sides, and two that open on the front and back sides, as indicated by dotted lines, to provide a structure that can process even large flow rates of fluid.

An annular space 15 is formed between the inlet passage 11 and the inlet-side connecting passage 32. Fluid flows in through the inlet passage 11, then circulates through this annular space 15, passes through the four inlet-side connecting passages 32, passes through the outlet-side connecting passage 33, and flows out of the outlet passage 12.

FIG. 3 is a perspective view of the sheet member 30 used in the embodiment of FIGS.
A male thread 34 is formed on the outer peripheral surface of the lower portion, and this male thread 34 is threadedly engaged with the female thread 14 of the valve body.
An inlet-side communicating passage 32 is formed in the center, and fluid passes through this inlet-side communicating passage 32, flows through an outlet-side communicating passage 33, and flows out from the outlet passage 12. A valve seat 31 is formed on the upper end surface. A male taper 35 is formed on the outer periphery of the upper part of the seat member 30, and a male taper abutment surface 36 abuts against the female taper abutment surface 17 (see Figure 2) to form a seal.

Figure 4(1) is a partial cross-sectional view of the valve chamber of a conventional valve, and Figure 4(2) is a partial cross-sectional view of the valve chamber of the present valve. Figure 4(3) is an enlarged view of the area surrounded by the dotted line in Figure 4(1), and Figure 4(4) is an enlarged view of the area surrounded by the dotted line in Figure 4(2).

In the conventional valve shown in Figure 4 (3), if the load applied to the upper seal portion of the seat member is _Ff , when the load _Ff decreases by _δFf due to loosening of the threads, temperature changes, etc., this decrease directly results in a 100% decrease in the surface pressure of the seal surface.

On the other hand, in Figure 4 (4) of the valve of the present application, if the load applied to the seal portion above the seat member 30 is _Ft , when the load _Ft is reduced by _δFt , the load reduction will only require a reduction in magnitude of sin θ (where θ is the taper half angle). Also, if the static friction coefficient between the valve body 10 and the seat member 30 is μ, a force of _μFt sin θ acts upward along the tapered surface, so the force required to maintain the seal between the seat member 30 and the valve body 10 is smaller than in the conventional structure.

As described above, the valve of the present invention can be suitably used as a valve that is less likely to leak between the seat member and the valve body when flowing high-temperature, high-pressure fluids, etc.

REFERENCE SIGNS LIST 1 valve 2 actuator 3 stem 4 valve element 5 fixing screw 10 valve body 11 inlet passage 12 outlet passage 13 valve chamber 14 female threaded portion 15 annular space 16 female taper 17 female taper abutment surface 20 plug 21 cover member 22 gasket 30 seat member 31 valve seat 32 inlet side communicating passage 33 outlet side communicating passage 34 male threaded portion 35 male taper 36 male taper abutment surface 40 tapered eccentric screw

Claims (4)

a valve body having a valve chamber communicating with an inlet passage and an outlet passage for a fluid;
a cylindrical seat member disposed in the valve chamber, the cylindrical seat member including an inlet-side communication passage communicating with the inlet passage, an outlet-side communication passage communicating with the outlet passage, and a valve seat formed on a periphery of an opening of the outlet-side communication passage;
a valve having a valve body that can be brought into contact with and separated from the valve seat,
A male taper is formed on the valve seat side end of the seat member, and the male taper presses against a female taper formed in the valve chamber to form a seal. A valve as described in claim 1, characterized in that a female thread portion engraved on the inner surface of the valve chamber and a male thread portion engraved on the outer surface of the seat member are threadedly engaged. A valve as described in claim 1, characterized in that a seat member retainer is arranged on the end side of the seat member opposite the valve seat, and the seat member retainer presses the seat member. A valve as described in claim 3, characterized in that the seat retainer and a female threaded portion engraved on the inner surface of the valve chamber are threadedly engaged.