valve

Abstract

To provide a valve in which a valve body can be easily attached to a stem and which does not generate abnormal noise or malfunction during operation. [Solution] A valve (1) comprising a valve body (10) having an inlet passage (11), an outlet passage (12), and a valve chamber (14) connecting the inlet passage and the outlet passage; an actuator that drives a linearly moving stem having a valve element (21) at one end that opens and closes the flow path by abutting against and separating from a valve seat (13) formed in the valve body; and a fixing member (43) that fixes a plunger (44) that contacts the side of the stem and is fixed directly or indirectly to the valve body, wherein the stem has a recess (32) at the other end opposite the one end that engages the tip of the plunger.

Description

[Technical Field]

[0001] The present invention relates to a valve. [Background technology]

[0002] Valves such as that described in Patent Document 2 have traditionally been used as valves for flowing chemicals and the like. Such valves use a diaphragm as the valve element, which controls the opening and closing of the flow path and prevents leakage to the actuator side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2019 / 208385 publication [Patent Document 2] Japanese Patent Application Publication No. 2022-96399 Summary of the Invention [Problem to be solved by the invention]

[0004] In the valve described in Patent Document 2, a diaphragm is attached to the lower end of the stem, and the stem and diaphragm are joined by screwing. When an attempt is made to screw the diaphragm onto the lower end of the stem with the stem attached to the actuator, the stem rotates with the actuator casing, making the work extremely difficult. Therefore, if an attempt is made to prevent the stem from rotating by forming a protrusion that engages with the groove of the stem as described in Patent Document 1, this may result in abnormal noise or malfunction during valve operation.

[0005] The present invention has been made in consideration of the above points, and its object is to provide a valve in which the valve body can be easily attached to the stem, and which does not generate abnormal noise or malfunction during valve operation. [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 communicating the inlet passage and the outlet passage; an actuator that drives a linearly moving stem having a valve element at one end that opens and closes a flow path by moving toward and away from a valve seat formed in the valve body; and a fixing member that fixes a plunger that contacts a side surface of the stem and is fixed to the actuator, wherein the stem has a recess at the other end opposite the one end that engages the tip of the plunger.

[0007] The valve of the present invention (1) is a valve having a linearly moving stem and a fixing member that fixes a plunger that contacts the side of the stem and is fixed to the actuator, and the stem has a recess on the other end opposite the one end that engages the tip of the plunger, so that malfunctions caused by the plunger are unlikely to occur during valve operation. Even when attaching the valve disc to the stem, co-rotation of the stem can be prevented by fitting the tip of the plunger into the recess, making it easy to attach the valve disc to the stem.

[0008] The present invention (2) is a valve of the present invention (1) in which the fully closed turning point of the stem that comes into contact with the plunger when the valve is in a fully closed state is defined as point P, the fully open turning point of the stem that comes into contact with the plunger when the valve is in a fully open state is defined as point Q, the upper end point that is the end point on the other end side of the recess in a side view is defined as point U, and the lower end point that is the end point on the one end side of the recess in a side view is defined as point L, and point U is on the other end side of point P and point L is on the one end side of point Q.

[0009] In the present invention (2), point U is closer to the other end than point P, and point L is closer to one end than point Q, and while the valve is operating, the tip of the plunger always contacts only the surface of the recess, so movement is smooth and no abnormal noise is generated.

[0010] The present invention (3) is a valve of the present invention (1) in which the fully closed turning point of the stem, which contacts the plunger when the valve is in a fully closed state, is defined as point P, and the lower end point, which is the end point on the side of the one end of the recess in a side view, is defined as point L, and point L is located closer to the other end than point P.

[0011] In the present invention (3), point L is located closer to the other end than point P, and while the valve is in operation, the tip of the plunger always contacts only the surface of the stem that is not recessed, so movement is smooth and no abnormal noise is generated.

[0012] The present invention (4) is the valve of any one of the present inventions (1) to (3), wherein the plunger is a ball plunger having a ball at the tip, and the ball is engaged in the recess when the valve is assembled.

[0013] In the valve of the present invention (4), the plunger is a ball plunger, and since it slides due to the rolling of the ball, it has good sliding properties, and the stem moves smoothly, eliminating the generation of abnormal noise. The tip of the plunger is pushed out by a spring, and there are pin plungers with a pin tip and ball plungers with a ball tip. Ball plungers are preferable because they have rolling properties.

[0014] The present invention (5) is a valve according to any one of the present inventions (1) to (3), in which a male thread is formed on one of the stem and the valve body, and a female thread is formed on the other, and the stem and the valve body are joined by screwing together.

[0015] In the present invention (5), the stem and the valve body are joined by screwing, which makes manufacturing easier. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a valve in which the valve body can be easily attached to the stem, and which does not generate abnormal noise or malfunction during operation. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a partially enlarged cross-sectional view of the entire valve of the first embodiment of the present invention in a fully closed state. [Figure 2] FIG. 2 is a partially enlarged cross-sectional view of the upper end portion of the valve shown in FIG. [Figure 3] 1 is a partially enlarged cross-sectional view of the entire valve of the first embodiment of the present invention in a fully open state. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of the upper end portion of the valve shown in FIG. 3. [Figure 5] FIG. 2 is a partially enlarged cross-sectional view of a portion of the valve according to the first embodiment of the present invention separated from the valve body during assembly. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view of the upper end portion of the valve shown in FIG. 5. [Figure 7] FIG. 10 is a partially enlarged cross-sectional view illustrating the position of a recess. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will 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.

[0019] The valve 1 shown in Figure 1 is a valve for controlling a fluid, and comprises an actuator 40 that includes a valve body 10, a bonnet 20, and a casing 30. The valve body 10 is formed with an inlet passage 11, an outlet passage 12, and a valve seat 13. The bonnet 20 is attached to the top of the valve body 10 by a method not shown. The casing 30 is attached to the bonnet 20.

[0020] Inside the bonnet 20, a valve element 21 attached to the lower end of a stem 31 abuts against the valve seat 13. The valve element 21 is attached by threading a female thread 26 at the lower end of the stem 31 into a male thread 25 attached to the top of the valve element 21. The valve body 21 includes a diaphragm 22, which is made up of a first layer 23 and a second layer 24. The first layer 23 is disposed on the flow path side and is made of a corrosion-resistant hard resin material. The second layer 24 is made of a soft resin material, and the first layer 23 and the second layer 24 are integral with each other. A diaphragm retainer 27 is provided on the second layer 24 to press the diaphragm 22. The stem 31 and the bonnet 20 are sealed with an O-ring 41.

[0021] The interior of the casing 30 is divided into a first chamber 37 and a second chamber 38, which are hermetically separated by a piston 35 equipped with a seal ring 36 and an O-ring 42. The upper end of the casing 30 has a hole (unnumbered) through which the stem 31 protrudes. A working fluid inlet 39 is attached to the casing 30, and the piston 35 is driven by the intake and exhaust of working fluid. A biasing member 33 (spring coil) is disposed between the upper surface of the piston 35 and a top plate (unnumbered) provided near the upper end of the casing 30, and the piston is pressed downward. When working fluid flows into the first chamber 37, the piston 35 is pushed upward, compressing the biasing member 33, maintaining equilibrium and opening the valve 1.

[0022] A fixed member 43 is attached to a hole in the top surface of the casing 30. The fixed member 43 is fixed to the actuator 40. A ball plunger 44 is attached to the fixed member 43, and a ball 45 contacts the side surface of the stem 31. A recess 32 is formed on the upper end side of the stem 31. In Figure 1, when the valve 1 is fully closed, the contact point where the ball 45 contacts the side surface of the stem 31 is the fully closed turn point P, also called point P.

[0023] Fig. 2 is a partially enlarged cross-sectional view of the upper end portion of the valve shown in Fig. 1. Ball 45 of ball plunger 44 does not enter recess 32 and is in contact with the cylindrical side surface of stem 31.

[0024] Figure 3 is a partially enlarged cross-sectional view of the valve of the first embodiment of the present invention in the fully open state. Some of the parts that were explained in Figure 1 will not be explained again. Working fluid flows in from working fluid inlet 39, and the internal pressure of first chamber 37 increases, pushing up piston 35, maintaining balance with the compressed biasing member 33, diaphragm 22 moving upward, and valve 1 entering the fully open state. The contact point at which ball 45 contacts the side surface of stem 31 at this time is full-open turning point Q, also called point Q.

[0025] Fig. 4 is a partially enlarged cross-sectional view of the upper end portion of the valve shown in Fig. 3. Ball 45 of ball plunger 44 does not enter recess 32 and is in contact with the cylindrical side surface of stem 31.

[0026] 5 is a partially enlarged cross-sectional view of the valve of the first embodiment of the present invention during assembly. The ball 45 of the ball plunger 44 fits into the recess 32, preventing rotational movement of the stem 31 around the central axis. Therefore, even when the male thread 25 of the valve element 21 is screwed into the female thread 26 at the lower end of the stem, the stem 31 does not rotate, and the valve element 21 can be easily attached to the stem 31. When the valve is in operation, the ball 45 only comes into contact with the cylindrical side surface of the stem 31, allowing smooth movement of the stem 31.

[0027] Figure 6 is a partially enlarged cross-sectional view of the upper end portion of the valve shown in Figure 5. A ball 45 fits into the recess 32, and rotational movement of the stem 31 around its axis is restricted.

[0028] 7 is a diagram showing a preferred position of the recess 32 in the stem 31. The stem 31 has points P and Q, and as described above, point P is the contact point between the stem 31 and the side surface of the ball 45 when the valve 1 is fully closed, and is the fully closed turning point. Point Q is the contact point between the stem 31 and the side surface of the ball 45 when the valve 1 is fully open, and is the fully open turning point. FIG. 7 shows all the valves in a fully closed state. The upper end point of the recess on the side of the other end in a side view is defined as point U, and the lower end point of the recess on the side of the one end in a side view is defined as point L.

[0029] As shown in Figure 7(A), if point L is above point P, ball 45 will not fit into recess 32 when the valve is in operation, and when the valve body is attached to the stem, the plunger prevents the stem from rotating with the actuator. As shown in Figure 7(B), if point L is between points P and Q, the plunger prevents the stem from rotating relative to the actuator when the valve body is attached to the stem, but when the valve is in operation, the ball 45 alternates between fitting into the recess 32 and coming into contact with a surface without the recess 32. As shown in Figure 7(C), when point U is above point P and point L is below point Q, the ball 45 always fits into the recess 32 when the valve is in operation, and when the valve body is attached to the stem, the plunger prevents the stem from rotating with the actuator. 7(D), if point U is below point P and point L is above point Q, when the valve is in operation, ball 45 will alternate between fitting into recess 32 and contacting a surface without recess 32. Furthermore, by pushing the stem into the actuator when assembling the valve body, the plunger can prevent the stem from rotating with the actuator. 7(E), if point U is between points P and Q and point L is below point Q, then when the valve is in operation, ball 45 will alternate between fitting into recess 32 and contacting a surface without recess 32. Furthermore, by pushing the stem into the actuator when assembling the valve body, the plunger can prevent the stem from rotating with the actuator.

[0030] From the analysis of Figure 7, in order to prevent co-rotation when assembling the valve body, Figures 7(A), 7(B) and 7(C) are more preferable than Figures 7(D) and 7(E), which require the stem to be pressed into the actuator. In order to ensure smooth operation of the stem when the valve is in operation and to prevent abnormal noise or malfunctions, Figures 7(A) and 7(C) are more preferable than Figures 7(B), 7(D) and 7(E), and Figure 7(A) is particularly preferable as it is not affected by the groove.

[0031] 1 to 7, the shape of the recess 32 is preferably a groove formed in the axial direction of the stem 31, but other shapes such as a depression, a through-hole perpendicular to the axis, a groove along the circumferential direction of the axis, etc. However, if the groove is along the circumferential direction of the axis, it is necessary that it does not extend along the entire circumference of the axis of the stem 31, because if it extends along the entire circumference of the axis of the stem 31, it will not be possible to stop the movement in the rotational direction. [Industrial Applicability]

[0032] As described above, the present valve is a valve in which the valve disc can be easily attached to the stem, and it is possible to provide a valve that does not generate abnormal noise or malfunction during valve operation. [Explanation of symbols]

[0033] 1; Valve 10; Valve body 11. Entrance passage 12;Exit passage 13: Valve seat 14; Valve chamber 20; bonnet 21; Valve body 22; diaphragm 23;1st layer 24;2nd layer 25; male thread 26; female thread 27: Diaphragm holder 30; casing 31; stem 32;Recess 33: biasing member 35; Piston 36;Seal ring 37;1st room 38;2nd room 39: Working fluid inlet 40; Actuator 41; O-ring 42; O-ring 43: Fixing member 44;Ball plunger 45;Ball P: Fully closed turning point Q: Full-open turning point U; upper end point L; lower end point

Claims

1. a valve body including an inlet passage, an outlet passage, and a valve chamber communicating the inlet passage and the outlet passage; an actuator that drives a linearly moving stem having a valve element at one end that opens and closes a flow path by coming into contact with and separating from a valve seat formed in the valve body; a fixing member that fixes a plunger that contacts a side surface of the stem and is fixed to the actuator, The stem has a recess on the other end opposite the one end for engaging the tip of the plunger.

2. In the stem, a fully closed turning point that contacts the plunger when the valve is in a fully closed state is defined as point P, a fully open turning point that contacts the plunger when the valve is in a fully open state is defined as point Q, an upper end point that is an end point on the other end side of the recess in a side view is defined as point U, and a lower end point that is an end point on the one end side of the recess in a side view is defined as point L, 2. The valve according to claim 1, wherein point U is located closer to the other end than point P, and point L is located closer to the one end than point Q.

3. In the stem, a fully closed turning point that contacts the plunger when the valve is in a fully closed state is defined as point P, and a lower end point that is an end point on the side of the one end of the recess in a side view is defined as point L, 2. The valve according to claim 1, wherein the point L is located closer to the other end than the point P.

4. 4. The valve according to claim 1, wherein the plunger is a ball plunger having a ball at its tip, and the ball is engaged in the recess when the valve is assembled.

5. A valve according to any one of claims 1 to 3, wherein one of the stem and the valve body has a male thread and the other has a female thread, and the stem and the valve body are joined by a screw engagement.

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