valve

Abstract

To provide a valve with a suspended valve body that applies even pressure to the valve seat when closed, making it less prone to seat leaks. [Solution] A valve 100 comprising a valve body 110 having an inlet passage 111, an outlet passage 112, and a valve chamber 113 connecting the inlet passage and the outlet passage; a valve element 140 that opens and closes a flow path by contacting and separating from a valve seat 114 formed on the valve body; an operating part 120 that moves the valve element in the axial direction of the valve element; and a stem 130 connecting the operating part and the valve element, wherein the stem has an engaging part 131 formed at one end on the valve element side that engages with the valve element, and the valve element has an engaged part 141 that engages with the engaging part, a recess 142 formed on the valve seat side of the engaged part, and a pin 150 is inserted into the recess such that one end protrudes from the recess towards the engaging part side, and when the valve is closed the end face of the engaging part on the valve element side presses the pin.

Description

Technical Field

[0001] This invention relates to a valve.

Background Art

[0002] When the valve is opened and closed by the contact and separation of the valve body connected to the stem with respect to the valve seat, the connection between the stem and the valve body may be a suspension structure. By adopting a suspension structure, the direction in which the valve body contacts the valve seat is less affected by the axial direction of the stem, and the centering of the valve body and the valve seat becomes easier.

[0003] The valve shown in FIG. 3 forms a suspension structure by the engagement of the engaging portion 338 at the lower part of the stem 330 and the engaged portion of the valve body 317 in the valve chamber 316. The engaging portion 338 has a large-diameter portion at the lower end and a reduced-diameter portion above it. By sliding the large-diameter portion through the window formed on the lower side surface of the engaged portion and inserting it, the engaging portion and the engaged portion are engaged, and the valve body 317 is suspended with respect to the stem.

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the valve has a valve body with a suspension structure, for the centering of the valve body and the valve seat, it is better that the stem end, which is the point of application of the stem thrust on the valve body, is near the valve seat contact surface or below the valve seat contact surface. It is desirable that the point P shown in FIG. 3 is near L or below L. This is because when the point of application of the stem thrust on the valve body (point P in the figure) is significantly above the valve seat contact surface as shown in FIG. 3, an unbalanced force with respect to the point of application occurs, which causes seat leakage. However, due to structural, processing, and other problems, it may be difficult to bring the stem end, which is the point of application, closer to the valve seat contact surface or dispose it below the valve seat contact surface.

[0005] The present invention has been made in view of the above, and its purpose is to provide a valve equipped with a suspended valve body in which pressure is evenly applied from the valve body to the valve seat when the valve is closed, and in which seat leakage is less likely to occur. [Means for solving the problem]

[0006] The present invention (1) is a valve comprising: a valve body having an inlet passage, an outlet passage, and a valve chamber connecting the inlet passage and the outlet passage; a valve element that opens and closes a flow path by contacting and separating from a valve seat formed on the valve body; an operating part for moving the valve element in the axial direction of the valve element; and a stem connecting the operating part and the valve element, wherein the stem has an engaging part formed at one end on the valve element side that engages with the valve element, the valve element has an engaged part that engages with the engaging part, a recess is formed on the valve seat side of the engaged part, a pin is inserted into the recess such that one end of the recess protrudes from the recess towards the engaging part side, and when the valve is closed, the end face of the engaging part on the valve element side presses the pin.

[0007] The valve of the present invention (1) has a stem that has an engaging portion formed at one end on the valve body side and engages with the valve body. The valve body has an engaged portion that engages with the engaging portion, and a recess is formed on the valve seat side of the engaged portion, and a pin is inserted into the recess such that one end of the pin protrudes from the recess toward the engaging portion side. When the valve is closed, the end face of the engaging portion on the valve body side presses against the pin, so that the point of force applied from the stem to the valve body can be brought closer to the valve seat contact surface or positioned below the valve seat contact surface, so that pressure is applied evenly to the valve seat when closed, making seat leaks less likely.

[0008] The present invention (2) is a valve according to the present invention (1), characterized in that the valve body has a tapered portion that contacts the valve seat.

[0009] In the present invention (2), since the valve body has a tapered portion, it may not be possible to position the engaging portion and the engaged portion towards the tip. In such cases, having a pin structure allows the point of application of force to be positioned towards the tip, so that even in valves with a long stem and a tapered portion in the valve body, pressure is applied evenly to the valve seat when closed, making seat leaks less likely.

[0010] The present invention (3) is a valve according to the present invention (1) or (2), characterized in that the bottom surface of the recess is formed below the valve seat.

[0011] In the present invention (3), the position of the point of application of force is lower than the valve seat contact surface, so that pressure is applied more evenly to the valve seat when closed, and seat leaks are further reduced. [Effects of the Invention]

[0012] According to the present invention, for a valve with a valve body suspension structure, the point at which the stem thrust force is applied to the valve body can be brought closer to the valve seat contact surface, or positioned below the valve seat contact surface. This allows for even application of force from the valve body to the valve seat, ensuring even pressure is applied to the valve seat when closed, thereby providing a valve that is less prone to seat leaks. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view of the entire valve and a part of its main components according to Embodiment 1 of the present invention. [Figure 2] This is a cross-sectional view of the entire valve and a part of its main components according to Embodiment 2 of the present invention. [Figure 3] This is a partial cross-sectional view of the valve described in Patent Document 1. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described in detail below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

[0015] The valve 100 shown in Figure 1(A) comprises a valve body 110, an operating section 120, a stem 130, a bonnet 133, and a valve element 140. The valve body 110 has an inlet passage 111 through which fluid flows in, an outlet passage 112 through which fluid flows out, and a valve chamber 113 that connects the inlet passage 111 and the outlet passage 112, with a valve seat 114 provided at the opening on the inlet passage 111 side. The valve element 140 is disposed in the valve chamber 113 facing the valve seat 114 and is connected to the operating section 120 by the stem 130. The valve is opened and closed by the operating section 120, which causes the valve element 140 to come into contact with and separate from the valve seat 114, thereby blocking and opening the flow path.

[0016] The stem 130 passes through the valve body 110 and is positioned inside the bonnet 133. The space between the bonnet 133 and the stem 130 is sealed with a gland packing to prevent the fluid flowing through the valve 100 from leaking to the outside.

[0017] An engaging portion 131 is formed at the lower end of the stem 130. A reduced diameter portion 134 is formed above the engaging portion 131, and the engaging portion 131 engages with a engaged portion 141 formed on the upper part of the valve body 140. When the engaging portion 131 is inserted into a window formed on the side surface of the valve body 140, the engaging portion and the engaged portion engage, and this engagement causes the valve body 140 to move up and down in conjunction with the up and down movement of the stem 130.

[0018] A recess 142 is formed from the bottom surface of the engaged portion 141, and a pin 150 is disposed in the recess 142. When the lower end surface of the engaged portion 131 presses the upper surface of the pin 150 downward, the lower end surface of the pin 150 presses the bottom surface of the recess 142. At this time, even if there is a very slight misalignment between the direction in which the engaged portion presses the pin and the direction in which the valve body presses the valve seat, the bottom surface of the pin 150 is supported at its free end relative to the recess, so no bending moment is generated in the valve body and force is applied evenly from the valve body to the valve seat. In order to obtain such an effect, it is preferable that the pin 150 is not constrained radially by the recess 142. It is also preferable that the bottom surface of the pin 150 is in contact with the recess 142 with a curved surface. The spring 135 is interposed between the lower part of the stem 130 and the upper surface of the valve body 140 and always presses the valve body 140 downward. This is provided to prevent chattering (rattling due to the influence of fluid pressure). As can be seen from FIG. 1(B), since the point of application P of the force generated by turning the operating part 120 approaches very close to the valve seat contact surface L, pressure is evenly applied from the valve body 140 to the valve seat 114 when the valve is closed, making it difficult for sheet leakage to occur.

[0019] FIG. 2(A) shows a partial cross-sectional view of the valve 200 of Example 2 of the present invention. The overall structure is the same as that of FIG. 1(A), and the corresponding reference numerals are the reference numerals of FIG. 1(A) plus 100. The following description will omit some parts, and the parts different from FIG. 1(A) will be described.

[0020] The valve body 240 has a tapered portion 243 that tapers downward. Since it tapers downward, there is a limit to disposing the engaged portion 241 downward. Due to the structure of the recess 242 and the pin 250, as shown in FIG. 2(B), the point of application P can be disposed below the valve seat contact surface L, so that the pressure applied from the valve body 240 to the valve seat 214 when the valve is closed becomes more uniform, making it more difficult for sheet leakage to occur.

[0021] In Examples 1 and 2, the operating part is a manual handle, but the present invention is also applicable to automatic valves provided with an electric motor or a pneumatic actuator.

Industrial Applicability

[0022] As described above, the present invention can provide a valve that has a valve body with a hanging structure and applies pressure evenly to the valve seat when closed, making it difficult for sheet leakage to occur.

Explanation of Reference Numerals

[0023] 100, 200; valve 110, 210; valve body 111, 211; inlet flow path 112, 212; Outlet channel 113, 213; valve chamber 114, 214; valve seat 120, 220; Operation section 130, 230; stem 131, 231; engaging part 133, 233 bonnet 134, 234; Reduced diameter part 135, 235; Spring 140, 240; valve body 141, 241; engaged portion 142, 242; recess 150, 250; pins 243; Tapered section P; Focus point L; Valve seat contact surface

Claims

1. A valve body having an inlet passage, an outlet passage, and a valve chamber connecting the inlet passage and the outlet passage, A valve body that opens and closes a flow path by contacting and separating from a valve seat formed on the valve body, An operating unit for moving the valve body in the axial direction of the valve body, A valve having an operating section and a stem connecting the valve body, The valve is characterized in that the stem has an engaging portion formed at one end on the valve body side that engages with the valve body, the valve body has an engaged portion that engages with the engaging portion, a recess is formed on the valve seat side of the engaged portion, a pin is inserted into the recess such that one end of the pin protrudes from the recess toward the engaging portion side, and when the valve is closed, the end face of the engaging portion on the valve body side presses against the pin.

2. The valve according to claim 1, characterized in that the valve body has a tapered portion that contacts the valve seat.

3. The valve according to claim 1 or 2, characterized in that the bottom surface of the recess is formed below the valve seat.

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