JP2016098897A - Pressure reduction valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure reduction valve capable of preventing generation of so-called spring noise by keeping an equilibrium state of a seat packing to a valve seat.SOLUTION: A valve element driving member 10 disposed in a pressure chamber 2b at a secondary side of a fluid passage and bringing a seat packing 20 into contact with a valve seat 5 or separating the same from the valve seat, has a valve rod 12 projecting from a piston portion 11 receiving energization force of a main spring 6 energizing to the seat packing 20, toward a primary-side valve chest 2a provided with the seat packing 20, and pressing the seat packing 20. The valve rod 12 is inserted to a communication passage 4c formed at a secondary side of the fluid passage and extending along the energizing direction of a valve spring 7. A supporting portion 14 radially projecting and kept into contact with an inner side face 4e of the communication passage 4c, is formed on a peripheral face 12b of the valve rod 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure reducing valve that decompresses a fluid supplied to a primary side of a fluid passage and discharges a decompressed fluid from a secondary side.

  Conventionally, the valve element arranged on the primary side is separated from the valve seat interposed in the middle of the fluid passage communicating with the primary side and the secondary side according to the pressure on the secondary side of the fluid passage. There is known a pressure reducing valve that opens and closes an opening formed in a valve seat to reduce the secondary side pressure (for example, see Patent Document 1). In this conventional pressure reducing valve, a valve spring is provided on the primary side of the fluid passage so as to urge the valve body in the direction of seating on the valve seat, and the valve body is pressed against the secondary side of the fluid passage to move away from the valve. A body driving member is arranged.

JP 2013-206176 A

By the way, in the conventional pressure reducing valve, the valve body driving member may be inclined with respect to the urging direction of the valve spring due to the sliding state of the valve body driving member or the influence of the pressure on the secondary side of the fluid passage. there were.
When the valve body is pressed while the valve body drive member is tilted with respect to the urging direction of the valve spring, the valve body is tilted with respect to the valve seat and fluid vibration is generated, thereby supporting the valve body drive member. There arises a problem that the main spring causes abnormal vibration and generates a so-called spring squeal.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a pressure reducing valve that can maintain a balanced state of a valve body with respect to a valve seat and prevent occurrence of so-called spring squealing.

In order to achieve the above object, the present invention provides a pressure reducing valve that decompresses a fluid supplied to a primary side of a fluid passage and discharges a decompressed fluid from a secondary side of the fluid passage. , A valve body, a valve spring, a main spring, and a valve body drive member.
The fluid passage guides the fluid supplied to the primary side to the secondary side.
The valve seat is formed at an intermediate position of the fluid passage so as to define the fluid passage on a primary side and a secondary side, and has an opening communicating the primary side and the secondary side of the fluid passage. Have.
The valve body is disposed on the primary side of the fluid passage, and opens and closes the fluid passage by opening and closing the opening of the valve seat.
The valve spring biases the valve body in a direction to seat the valve body on the valve seat.
The main spring biases the valve body drive member toward the valve body.
The valve body driving member is disposed on the secondary side of the fluid passage, and moves the valve body away from the valve seat according to the pressure on the secondary side of the fluid passage.
The fluid passage has a communication passage extending along a biasing direction of the valve spring on a secondary side where the valve body driving member is disposed, and the valve body driving member includes the main spring. A piston portion that slides upon receiving the urging force, and a valve rod that protrudes from the piston portion toward the primary side where the valve body is disposed, is inserted into the communication passage, and presses the valve body at the tip. Have.
Furthermore, a support portion that protrudes in the radial direction from the peripheral surface and contacts the inner side surface of the communication path is formed on the valve rod.

Therefore, in the pressure reducing valve according to the present invention, the valve rod of the valve body driving member inserted into the communication passage of the fluid passage is formed with a support portion that protrudes in the radial direction from the peripheral surface and contacts the inner surface of the communication passage. Yes.
Therefore, when the piston part slides, the support part continues to come into contact with the inner surface of the communication path, and the valve element regardless of the sliding state of the piston part or the influence of the pressure on the secondary side of the fluid path. The drive member can be prevented from being inclined with respect to the biasing direction of the valve spring.
Thereby, a valve body can be pressed along the urging | biasing direction of a valve spring with a valve body drive member. That is, the valve body can be moved in equilibrium with respect to the valve seat, and the valve body can be prevented from being inclined with respect to the valve seat and so-called spring noise.

1 is a longitudinal sectional view showing a pressure reducing valve of Example 1. FIG. It is a principal part enlarged view which shows the valve seat of Example 1. FIG. (a) is a longitudinal cross-sectional view which shows the sheet packing of Example 1, (b) is a top view which shows the sheet packing of Example 1. FIG. (a) is a longitudinal cross-sectional view which shows the valve body drive member of Example 1, (b) is a top view which shows the valve body drive member of Example 1. FIG. It is a longitudinal cross-sectional view which shows the pressure-reduction valve of a comparative example. It is explanatory drawing which shows the state which closed the opening in the state which the valve body drive member inclined in the pressure-reduction valve of a comparative example. In the pressure-reduction valve of a comparative example, it is a principal part enlarged view which shows the state which opened the opening in the state which the valve body drive member inclined. In the pressure-reduction valve of Example 1, it is a longitudinal cross-sectional view which shows the state which open | released opening. It is a graph which shows the measurement result of the flow volume with respect to the secondary side setting pressure (target pressure) in the pressure-reduction valve of Example 1, and the measurement result of the flow volume with respect to the secondary side setting pressure (target pressure) in the pressure-reduction valve of a comparative example. It is a longitudinal cross-sectional view which shows the pressure-reduction valve to which the seat packing of the shape different from Example 1 is applied, (a) shows an opening closed state, (b) shows an opening open state.

  Hereinafter, the form for implementing the pressure-reduction valve of this invention is demonstrated based on Example 1 shown in drawing.

Example 1
FIG. 1 is a longitudinal sectional view illustrating a pressure reducing valve according to the first embodiment. FIG. 2 is an enlarged view of a main part showing the valve seat of the first embodiment. FIG. 3A is a longitudinal sectional view showing the sheet packing of the first embodiment, and FIG. 3B is a plan view showing the sheet packing of the first embodiment. FIG. 4A is a longitudinal sectional view showing the valve body drive member of the first embodiment, and FIG. 4B is a plan view showing the valve body drive member of the first embodiment. Hereinafter, based on FIGS. 1-4, the structure of the pressure-reduction valve of Example 1 is demonstrated.

  The pressure reducing valve 1 of the first embodiment is a so-called direct acting pressure reducing valve in which a change in fluid pressure on the primary side is directly changed to a flow rate change. The base member 2 constituting the housing and the base member 2 are attached to the base member 2 by screws N. The separator 4 is sandwiched between the base member 2 and the bonnet 3. The separator 4 includes a cylinder portion 4a, a valve seat portion 4b, a communication passage 4c that penetrates the cylinder portion 4a and the valve seat portion 4b, and an opening 4d provided in a lower end portion of the communication passage 4c. Yes.

A piston portion 11 of the valve element driving member 10 is fitted to the cylinder portion 4a so as to be capable of reciprocating in the vertical direction in FIG. On the other hand, a seat packing (valve element) 20 is disposed in the valve chamber 2 a formed in the base member 2.
Here, the piston portion 11 is a portion that receives a biasing force of the main spring 6 that biases the valve body driving member 10 toward the seat packing 20. A valve rod 12 extending toward the seat packing 20 is formed at the center of the piston portion 11. The valve stem 12 is inserted into the communication passage 4c, and the tip projects from the opening 4d. And the center part of the seat packing 20 is pressed with the front-end | tip 12a of the valve stem 12 which protruded from 4 d of opening. At this time, the tip end 12 a of the valve stem 12 is fitted into a later-described recess 23 of the seat packing 20.
Furthermore, a relief passage 13 that penetrates the piston portion 11 and the valve rod 12 is formed in the valve body driving member 10. The relief passage 13 is opened when the secondary side pressure exceeds a set value, and the pressure is released from the atmosphere opening hole 3 a formed in the bonnet 3.

  As shown in FIG. 2, the valve seat portion 4b is formed by protruding the valve seat 5 at a position surrounding the opening 4d. A convex curved surface W that smoothly continues from the inner side surface 4e of the communication passage 4c to the valve seat 5 is formed at the peripheral edge of the opening 4d. The curved surface W can be constituted by, for example, a curved surface having a radius R of 0.5 or less.

And as shown in FIG. 1, the sheet packing 20 is arrange | positioned in the position facing the opening 4d. As shown in FIG. 3, the seat packing 20 is formed in a rectangular guide portion 21 as a whole, a tapered cone-shaped seating surface 22 that decreases in diameter toward the opening 4 d, and a central portion of the top surface of the seat packing 20. A conical recess 23.
Here, the tapered cone-shaped seating surface 22 is inclined at an angle Q of 45 degrees with respect to the axis X of the seat packing 20 and extends around the recess 23 as shown in the figure, for example. The sheet packing 20 is formed, for example, by covering a brass cored bar with a rubber material such as nitrile rubber.

The seat packing 20 is disposed in a valve chamber 2 a formed in the base member 2. The side wall of the valve chamber 2a is formed in a square shape, and the seat packing 20 is slidable in the vertical direction in FIG. 1 by engaging a rectangular guide portion 21 with the side wall of the valve chamber 2a. A valve spring 7 is disposed in the valve chamber 2 a, and the seat packing 20 is constantly urged toward the valve seat 5 by the elastic force of the valve spring 7.
When the seat packing 20 is seated on the valve seat 5, the tapered cone-shaped seating surface 22 is crimped to the curved surface W at the peripheral edge of the opening 4 d surrounded by the valve seat 5, and between this curved surface W, An annular line seal is formed. At this time, as shown in FIG. 4, the upper part of the tapered cone-shaped seating surface 22 enters the inside of the opening 4d.

  Here, the base member 2 communicates with a primary port (not shown) communicating with the valve chamber 2a and a pressure chamber 2b defined between the piston portion 11 and the cylinder portion 4a of the valve body driving member 10. A fluid passage that extends from the primary port to the secondary port 2c. The fluid passage includes a primary side fluid passage extending from the primary side port through the valve chamber 2a to the valve seat 5, a secondary side port passing through the valve seat 5 through the communication passage 4c and the pressure chamber 2b in this order. And a secondary fluid passage extending up to 2c.

Further, the main spring 6 is disposed between the back surface of the piston portion 11 of the seat packing 20 and the spring receiver 6 a disposed inside the bonnet 3. The spring receiver 6 a is in contact with the tip 3 c of the adjustment screw 3 b that is screwed into the bonnet 3. A sliding surface 3d having a convex spherical system is formed at the tip 3c of the adjusting screw 3b, and the spring receiver 6a is rotatably supported by the spherical sliding surface 3d. Since the sliding surface 3d has a convex spherical shape, the frictional resistance with the spring receiver 6a can be kept low.
That is, if the adjustment handle 8 fixed to the adjustment screw 3b is rotated, the set pressure of the main spring 6 can be changed with a small force.

Further, in the first embodiment, the valve rod 12 of the valve body driving member 10 is formed with a plurality of support portions 14 that protrude in the radial direction from the peripheral surface 12b and contact the inner side surface 4e of the communication passage 4c.
Here, the valve stem 12 has a cylindrical shape in which the relief passage 13 passes through the central portion along the axial direction. On the other hand, as shown in FIG. 4, the support portion 14 has six support members extending in the radial direction from the center position (axis O ₁ ) of the cylindrical valve stem 12 by setting the opening angles to each other at equal intervals. It has a wall 14a.

  Each support wall 14 a has a rib shape extending along the longitudinal direction (axial direction) of the valve stem 12. Further, the height of the support wall 14a (projection length from the peripheral surface 12b of the valve stem 12) is such that the tip of each support wall 14a and the communication passage when the valve stem 12 is disposed at the center position of the communication passage 4c. The dimension is set such that the inner surface 4e of 4c comes into slidable contact.

Next, the operation will be described.
First, “the configuration and problems of the pressure reducing valve of the comparative example” will be described, and subsequently, “the operation for maintaining the equilibrium state of the seat packing” in the pressure reducing valve 1 of the first embodiment will be described.

"Composition and problem of pressure reducing valve of comparative example"
FIG. 5 is a longitudinal sectional view showing a pressure reducing valve of a comparative example. FIG. 6 is an explanatory diagram showing a state in which the opening is closed while the valve body drive member is tilted in the pressure reducing valve of the comparative example. FIG. 7 is an explanatory view showing a state in which the opening is opened while the valve body drive member is tilted in the pressure reducing valve of the comparative example. Hereinafter, based on FIGS. 5-7, the structure and subject of the pressure-reduction valve of a comparative example are demonstrated.

  As illustrated in FIG. 5, the pressure reducing valve 100 of the comparative example includes a base member 102 and a bonnet 103 that constitute a housing, and a separator 104 that is sandwiched between the base member 102 and the bonnet 103. Here, the separator 104 has a communication passage 104c that penetrates the cylinder portion 104a and the valve seat portion 104b, and an opening 104d that is located at the lower end portion of the valve seat portion 104b and opens the communication passage 104c.

And the piston part 105a of the valve body drive member 105 is fitted in the pressure chamber 102b divided by the cylinder part 104a so that it can reciprocate in the up-down direction in FIG. A seat packing (valve element) 106 supported by a valve spring 107 is disposed in the valve chamber 102 a formed in the base member 102. The valve spring 107 constantly urges the seat packing 106 toward the opening 104d.
Further, a valve rod 105b extending toward the seat packing 106 is formed at the center of the piston portion 105a. The valve stem 105b is inserted into the communication path 104c, and the tip 105c projects from the opening 104d. And the center part of the seat packing 106 is pressed by the front-end | tip 105c of the valve rod 105b protruded from 104 d of openings, and the opening 104d formed in the lower end part of the valve seat part 104b is opened and closed.

  Here, the valve stem 105b is a cylindrical member having a smooth peripheral surface, and is set to an outer dimension smaller than the inner diameter dimension of the communication path 104c.

  In the pressure reducing valve 100 of this comparative example, when the pressurized fluid is decompressed, the pressure in the valve chamber 102a on the primary side of the fluid passage (hereinafter referred to as “primary pressure P1”) and the fluid passage 2 Due to the balance between the pressure in the pressure chamber 102b on the secondary side (hereinafter referred to as “secondary pressure P2”) and the set pressure (target pressure), the piston portion 105a of the valve element drive member 105 moves in the vertical direction (valve rod). 105b in the axial direction).

Here, the valve body driving member 105 may be inclined with respect to the urging direction of the valve spring 107 that supports the seat packing 106 due to the sliding state of the piston portion 105a, the secondary pressure P2, and the like.
That is, an O-ring 108 is provided on the outer peripheral surface of the piston portion 105a to prevent fluid leakage from between the piston portion 105a and the cylinder portion 104a. However, there is a dimensional tolerance between the piston portion 105a and the cylinder portion 104a so that the valve body driving member 105 can slide. Further, the outer dimension of the valve stem 105b is set to a value smaller than the inner diameter dimension of the communication passage 104c, and a gap is generated between the valve stem 105b and the communication passage 104c. As a result, the valve body driving member 105 is inclined due to the influence of the balance of the secondary pressure P2 received by the piston portion 105a. In addition, the valve body drive member 105 tends to incline, so that the thickness (size of a sliding direction) of the piston part 105a is small.

  When the valve body driving member 105 is tilted, the valve rod 105b cannot press the seat packing 106 along the urging direction of the valve spring 107, and the seat packing 106 is against the opening 104d of the valve seat portion 104b. It will move away and in a tilted state.

As a result, as shown in FIG. 6, when the opening 104 d of the valve seat portion 104 b is closed by the seat packing 106, it becomes difficult for the peripheral portion of the opening 104 d to uniformly contact the seating surface 106 a of the seat packing 106. That is, the contact pressure generated between the sheet packing 106 and the opening 104d partially varies.
As a result, the seat packing 106 rattles against the opening 104d, causing chattering that causes the sheet packing 106 to repeatedly hit the valve seat portion 104b. When the chattering causes a fluid vibration in the secondary fluid, and when the frequency of the fluid vibration and the natural frequency of the main spring 109 supporting the valve body driving member 105 coincide, A spring squeal that 109 vibrates abnormally occurs.
That is, when the valve body driving member 105 is tilted with respect to the urging direction of the valve spring 107 that supports the seat packing 106, the equilibrium state of the seat packing 106 with respect to the valve seat portion 104b cannot be maintained, and a spring squeal is generated. It was difficult to suppress.

Furthermore, as shown in FIG. 7, when the seat packing 106 is inclined by pressing the seat packing 106 with the valve rod 105b to open the opening 104d, the gap dimension between the opening 104d and the seat packing 106 is It is not even along the peripheral edge of 104d.
For this reason, when the fluid flows into the communication path 104c, it cannot flow evenly from the entire circumference of the opening 104d, resulting in partial variations. As a result, the fluid cannot flow smoothly, leading to a decrease in the flow rate.

[Equilibration maintaining effect of sheet packing]
FIG. 8 is a longitudinal sectional view showing the pressure reducing valve of Example 1 in a state where the seat packing is opened. Hereinafter, based on FIG.1 and FIG.8, the equilibrium state maintenance effect | action of the seat packing in the pressure-reduction valve of Example 1 is demonstrated.

  In the pressure reducing valve 1 of the first embodiment, the primary pressure P1, which is the pressure in the valve chamber 2a provided on the primary side of the fluid passage, and the pressure in the pressure chamber 2b, provided on the secondary side of the fluid passage. Due to the balance between a certain secondary pressure P2 and the set pressure (target pressure), the piston portion 11 of the valve element drive member 10 slides in the vertical direction (the axial direction of the valve stem 12), and the pressure of the pressurized fluid is set. The pressure is reduced to a pressure.

That is, when the secondary pressure P2 exceeds the set pressure, as shown in FIG. 1, the seat packing 20 is pressed against the valve seat 5 by the urging force of the valve spring 7, and the opening 4d is closed. Thereby, the flow of the pressure fluid into the pressure chamber 2b is prevented, and the secondary pressure P2 is maintained.
On the other hand, when the secondary pressure P2 is lower than the set pressure, the tip 12a of the valve rod 12 protrudes from the opening 4d by the urging force of the main spring 6, and presses the seat packing 20 from the valve seat 5, as shown in FIG. Separate. As a result, the opening 4d is opened, and the pressure fluid flows into the pressure chamber 2b via the communication path 4c, and the secondary pressure P2 rises.

Here, the valve rod 12 of the valve body driving member 10 is formed with a plurality of support portions 14 that protrude in the radial direction from the peripheral surface 12b and contact the inner side surface 4e of the communication passage 4c.
Therefore, as shown in FIGS. 1 and 8, when the piston portion 11 of the valve body driving member 10 slides in the cylinder portion 4a, the support portion 14 slides while contacting the inner side surface 4e of the communication passage 4c. .

  Thereby, the valve stem 12 moves along the axial direction of the communication passage 4c, and the posture of the valve body driving member 10 is regulated. And it can prevent that this valve body drive member 10 inclines with respect to the urging | biasing direction of the seat packing 20 by the valve spring 7, and can press the seat packing 20 along the urging | biasing direction. And the seat packing 20 can be moved, maintaining the equilibrium state of the seat packing 20 with respect to the valve seat 5.

Therefore, as shown in FIG. 1, when the opening 4 d is closed by the seat packing 20, the valve seat 5 uniformly contacts the entire circumference of the seating surface 22 of the seat packing 20. That is, the contact pressure generated between the seat packing 20 and the valve seat 5 is uniform over the entire circumference.
As a result, the seat packing 20 can stably come into contact with the valve seat 5 without rattling, and chattering can be prevented when the seat packing 20 repeatedly hits the valve seat 5. Further, by preventing chattering from occurring, fluid vibration can also be prevented from occurring, and spring noise that causes the main spring 6 to vibrate abnormally can be suppressed.

Further, as shown in FIG. 8, even when the seat packing 20 is pressed by the valve stem 12 to open the opening 4d, the equilibrium state of the seat packing 20 with respect to the valve seat 5 is maintained, so the opening 4d and the seat packing are maintained. The size of the gap with the 20 seating surfaces 22 can be made constant over the entire circumference of the opening 4d.
Therefore, when the fluid flows from the valve chamber 2a to the communication passage 4c, it flows evenly from the entire circumference of the opening 4d. As a result, the fluid can flow smoothly, and a sufficient flow rate can be ensured even if the six support walls 14a protrude in the communication path 4c.

  FIG. 9 shows the measurement result of the flow rate with respect to the secondary set pressure (target pressure) in the communication passage 4c in the pressure reducing valve 1 of the first embodiment, and the secondary side in the communication passage 104c in the pressure reducing valve 100 of the comparative example. The measurement result of the flow rate with respect to the set pressure (target pressure) is shown. At this time, the primary pressure is set to a predetermined constant pressure. Moreover, the result of the pressure reducing valve 1 of Example 1 is shown by a solid line, and the result of the pressure reducing valve 100 of the comparative example is shown by a one-dot chain line.

As shown in FIG. 9, in both the pressure reducing valve 1 of the first embodiment and the pressure reducing valve 100 of the comparative example, the flow rate flowing through the communication passages 4c and 104c increases as the secondary set pressure (target pressure) increases. However, it can be seen that the pressure reducing valve 1 of Example 1 has a higher flow rate.
That is, in the pressure reducing valve 1 of the first embodiment, the support wall 14a projects into the communication path 4c, so that the fluid passage area of the communication path 4c is the communication in the pressure reducing valve 100 of the comparative example having no support portion. Although it is less than the fluid passage area of the passage 104c, it can be seen that maintaining the equilibrium state of the seat packing 20 makes the fluid flow smooth and ensures a sufficient flow rate.

  Moreover, in this Example 1, the support part 14 is extended along the longitudinal direction of the communicating path 4c. Therefore, the contact area between the support portion 14 and the communication path 4c can be increased, and the posture of the valve body driving member 10 can be stably regulated. Moreover, the support part 14 will extend along the flow direction of the fluid which flows through the communicating path 4c, it is difficult to inhibit the flow of the fluid, and the fall of the flow rate can be prevented.

Furthermore, in the first embodiment, the support portion 14 has six support walls 14a extending in the radial direction from the center position (axis O ₁ ) of the valve stem 12 by setting the opening angles to each other at equal intervals. ing.
Therefore, the periphery of the center position (axis line O ₁ ) of the valve stem 12 can be supported uniformly, and the posture of the valve stem 12 can be regulated with high accuracy. As a result, the posture of the valve body driving member 10 is more stable, and the seat packing 20 can be pressed with high accuracy along the urging direction.

Next, the effect will be described.
In the pressure reducing valve 1 of the first embodiment, the following effects can be obtained.

(1) a fluid passage (valve chamber 2a, pressure chamber 2b) for guiding the fluid supplied to the primary side to the secondary side;
The fluid passage (valve chamber 2a, pressure chamber 2b) is formed in the middle of the fluid passage (valve chamber 2a, pressure chamber 2b) so as to define the primary side and the secondary side, and the fluid passage A valve seat 5 having an opening 4d for communicating the primary side (valve chamber 2a) and the secondary side (pressure chamber 2b) of
A valve body (seat packing 20) disposed on the primary side (valve chamber 2a) of the fluid passage and opening and closing the opening 4d of the valve seat 5;
A valve spring 7 for urging the valve body (seat packing 20) in a direction for seating on the valve seat 5;
The valve body (seat) is disposed on the secondary side (pressure chamber 2b) of the fluid passage and slides according to the pressure (secondary pressure P2) on the secondary side (pressure chamber 2b) of the fluid passage. A valve body driving member 10 for moving the packing 20) to and from the valve seat 5;
A main spring 6 for urging the valve body drive member 10 toward the valve body (seat packing 20),
In the pressure reducing valve 1 for decompressing the fluid supplied to the primary side (valve chamber 2a) of the fluid passage and discharging the decompressed fluid from the secondary side (pressure chamber 2b) of the fluid passage,
The fluid passage (valve chamber 2a, pressure chamber 2b) is a communication passage extending along the biasing direction of the valve spring 7 on the secondary side (pressure chamber 2b) where the valve element driving member 10 is disposed. 4c,
The valve body driving member 10 is a piston portion 11 that receives the urging force of the main spring 6, and from the piston portion 11 toward the primary side (valve chamber 2a) on which the valve body (seat packing 20) is disposed. And a valve rod 12 that protrudes and is inserted into the communication passage 4c and presses the valve body (seat packing 20) at the tip 12a,
The valve stem 12 is formed with a support portion 14 that protrudes in the radial direction from the peripheral surface 12b and contacts the inner side surface 4e of the communication passage 4c.
Thereby, the balance state of the valve body (seat packing 20) with respect to the valve seat 5 can be maintained, and the occurrence of so-called spring squealing can be prevented.

(2) The support portion 14 is configured to extend along the longitudinal direction of the communication path 4c.
Thereby, in addition to the effect of (1), the contact area between the support portion 14 and the communication path 4c is increased while preventing the flow rate in the communication path 4c from decreasing, and the posture of the valve body driving member 10 is stably maintained. Can be regulated.

(3) The support portion 14 has at least three support walls 14a with the opening angles set at equal intervals.
Thereby, in addition to the effect of (1) or (2), the posture of the valve body driving member 10 can be further stabilized, and the seat packing 20 can be pressed accurately along the urging direction.

  As mentioned above, although the pressure-reduction valve of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The summary of the invention which concerns on each claim of a claim Unless it deviates, design changes and additions are allowed.

  In the first embodiment, the seating surface 22 of the seat packing 20 is formed in a tapered cone shape whose tip is reduced in diameter toward the opening 4d, and the curved surface W of the peripheral edge of the opening 4d that the seat packing 20 and the valve seat 5 surround. Although an example in which an annular line seal is formed between the two is shown, the present invention is not limited thereto. For example, like the pressure reducing valve 40 shown in FIG. 10, the seating surface 42 of the seat packing 41 pressed by the valve rod 12 may be a flat surface parallel to the valve seat 5. In FIG. 10, a recess 43 is formed at the center of the seat packing 20 so that the tip 12 a of the valve stem 12 contacts.

  In such a pressure reducing valve 40, when the seat packing 41 is urged toward the valve seat 5 by the elastic force of the valve spring 7 and is seated on the valve seat 5, the seating surface 42 formed on the flat surface is A face seal is formed in surface contact with the valve seat 5 and surrounding the opening 4d.

  Even in this case, as shown in FIGS. 10A and 10B, when the valve body driving member 10 slides, the valve body driving member 10 is inclined by the support portion 14 formed on the valve rod 12. This can be prevented, and the equilibrium state of the seat packing 41 with respect to the valve seat 5 can be maintained. Thereby, the adhesiveness of the valve seat 5 and the seating surface 42 of the seat packing 41 can be improved, and the occurrence of chattering can be suppressed even with the face seal.

  In the first embodiment, the six support walls 14a are formed on the peripheral surface 12b of the valve rod 12, but the present invention is not limited thereto. Since the support portion has at least three support walls, the valve stem 12 can be stably supported.

DESCRIPTION OF SYMBOLS 1 Pressure reducing valve 2 Base member 2a Valve chamber 2b Pressure chamber 2c Secondary side port 3 Bonnet 4 Separator 4a Cylinder part 4b Valve seat part 4c Communication path 4d Opening 4e Inner side surface 5 Valve seat 6 Main spring 7 Valve spring 10 Valve body drive member 11 Piston part 12 Valve rod 13 Relief passage 14 Support part 20 Seat packing (valve element)

Claims (3)

A fluid passage for guiding the fluid supplied to the primary side to the secondary side;
A valve seat formed at an intermediate position of the fluid passage so as to define the fluid passage on a primary side and a secondary side, and having an opening communicating the primary side and the secondary side of the fluid passage;
A valve body that is disposed on the primary side of the fluid passage and opens and closes the opening of the valve seat;
A valve spring that urges the valve body in a direction to be seated on the valve seat;
A valve body driving member that is arranged on the secondary side of the fluid passage and slides according to the pressure on the secondary side of the fluid passage, and moves the valve body away from and in contact with the valve seat;
A main spring that urges the valve body drive member toward the valve body,
A pressure reducing valve that decompresses the fluid supplied to the primary side of the fluid passage and discharges the decompressed fluid from the secondary side of the fluid passage;
The fluid passage has a communication passage extending along a biasing direction of the valve spring on the secondary side where the valve body driving member is disposed,
The valve body driving member is inserted into the communication passage by projecting toward the primary side where the valve body is disposed from the piston portion receiving the urging force of the main spring, and at the tip, the valve body A valve stem for pressing,
A pressure-reducing valve, wherein a support portion that protrudes in a radial direction from a peripheral surface and contacts an inner surface of the communication path is formed on the valve rod. The pressure reducing valve according to claim 1,
The said support part is extended along the longitudinal direction of the said communicating path. The pressure reducing valve characterized by the above-mentioned. In the pressure reducing valve according to claim 1 or 2,
The said support part has at least 3 support wall which set the mutual opening angle at equal intervals. The pressure reducing valve characterized by the above-mentioned.