阅读说明：本技术 减压阀 (Pressure reducing valve ) 是由 井上和久 于 2021-03-25 设计创作，主要内容包括：本发明提供能够防止在阀芯的下游侧产生紊流、提高流体流速的减压阀。该减压阀具有：致动器,其使预先调整好的按压力发挥作用；主体,其具有流入口、流出口及流体通路；供气口(隔壁),其将流体通路划分成一次侧的流入通路和二次侧的流出通路；阀座,其设置在贯通供气口的阀开口的周围；以及阀芯,其开闭阀开口。具有：膜片,其被致动器和主体夹持而张紧设置；压力室,其使二次侧的流出通路的压力作用于膜片；弹簧构件,其对阀芯向闭阀方向施力。二次侧的流出通路以与阀芯的动作方向正交的方式朝向流出口延伸。主体具备吸管(吸引通路),并且具备薄板状的分隔件,该分隔件将二次侧的流出通路的内部分割为吸管开口的第一通路和相反侧的第二通路。(The invention provides a pressure reducing valve capable of preventing turbulence from being generated at the downstream side of a valve core and improving the flow velocity of fluid. The pressure reducing valve has: an actuator that causes a preset pressing force to act; a body having an inlet, an outlet, and a fluid passage; an air supply port (partition wall) that divides the fluid passage into an inflow passage on the primary side and an outflow passage on the secondary side; a valve seat provided around a valve opening penetrating the air supply opening; and a valve body that opens and closes the valve opening. Comprising: a diaphragm clamped in tension by the actuator and the body; a pressure chamber for applying pressure of the secondary-side outflow passage to the diaphragm; and a spring member that urges the valve body in a valve closing direction. The secondary-side outflow passage extends toward the outflow port so as to be orthogonal to the operating direction of the valve element. The main body is provided with a suction pipe (suction passage), and a thin plate-like partition member that divides the interior of the secondary-side outflow passage into a first passage in which the suction pipe opens and a second passage on the opposite side.)

1. A pressure reducing valve is provided with:

an actuator that causes a preset pressing force to act;

a body having an inlet port into which a fluid supplied from a fluid source flows, an outlet port from which the fluid flowing in from the inlet port flows to the outside, and a fluid passage for communicating the inlet port and the outlet port to allow the fluid to flow;

a partition wall provided in the main body and dividing the fluid passage into a primary-side inflow passage and a secondary-side outflow passage;

a valve seat that penetrates the partition wall and is provided around a valve opening that communicates the primary-side inflow passage and the secondary-side outflow passage;

a valve body having a valve portion that is seated on or separated from the valve seat, the valve body opening and closing the valve opening;

a diaphragm that is sandwiched between the actuator and the main body, is stretched in a direction orthogonal to an operation direction of the valve body, and operates the valve body in a direction in which the valve opening is opened by receiving a pressing force from the actuator;

a pressure chamber that causes the pressure of the secondary-side outflow passage to act on the diaphragm to operate the valve element in a direction in which the valve opening is closed; and

a spring that generates an urging force that urges the valve element in a direction in which the valve opening is closed,

the pressure reducing valve is characterized in that,

the secondary-side outflow passage extends in a direction parallel to the direction in which the diaphragm is stretched, and extends toward the outflow port so as to be orthogonal to the direction in which the valve element operates,

the main body includes a suction passage that communicates the secondary-side outflow passage with the pressure chamber, and a thin-plate-shaped partition that divides the interior of the secondary-side outflow passage into a first passage in which the suction passage opens and a second passage on the opposite side.

2. The pressure reducing valve of claim 1,

a fluid having a relatively high flow rate flows in the first passage, and a fluid having a relatively low flow rate flows in the second passage.

3. The pressure reducing valve according to claim 1 or 2,

the partition is provided inside a ring fitted to a wall surface of the secondary-side outflow passage, and a through hole connected to the suction passage is formed in the ring.

4. The pressure reducing valve according to claim 1 or 2,

the partition is formed in a cross-sectional shape of an airfoil and configured to increase a flow velocity of the fluid flowing in the first passage.

5. The pressure reducing valve of claim 3,

the partition is formed in a cross-sectional shape of an airfoil and configured to increase a flow velocity of the fluid flowing in the first passage.

6. The pressure reducing valve of claim 4,

the suction passage is located at a position opposite to a maximum wing thickness position of the partition.

7. The pressure reducing valve of claim 5,

the suction passage is located at a position opposite to a maximum wing thickness position of the partition.

Technical Field

The present invention relates to a pressure reducing valve in which a valve element operates so that the pressure of fluid on the secondary side is constant.

Background

Conventionally, as a pressure reducing valve in which a valve body operates so that the pressure of a secondary-side fluid is constant, for example, a pressure reducing valve described in patent document 1 is known. As shown in fig. 12, the pressure reducing valve disclosed in patent document 1 includes a valve body 2 that opens and closes a fluid passage 1, and an actuator 3 that drives the valve body 2. The fluid flows from the right side to the left side in fig. 12 in the fluid passage 1.

The actuator 3 includes a spring member 4 that biases the valve body 2 in the valve opening direction, and a pressure chamber 6 in which a diaphragm 5 connected to the valve body 2 forms a part of a wall. The pressure chamber 6 communicates with the downstream side of the valve body 2 of the fluid passage 1 through a communication passage 7, and the pressure of the fluid passage 1a on the downstream side is introduced through the communication passage 7. The valve body 2 is stopped in a state where the pressure of the pressure chamber 6 and the spring force of the spring member 4 are balanced, and the pressure of the pressure chamber 6 decreases as the pressure of the downstream side fluid passage 1a decreases, and moves in the valve opening direction by the spring force of the spring member 4.

In the pressure reducing valve shown in patent document 1, the fluid flows as indicated by solid arrows and broken arrows in fig. 12. Solid arrows indicate flow paths of fluid flowing at a high flow rate and a high flow rate, and dotted arrows indicate flow paths of fluid flowing at a low flow rate and a low flow rate. In this pressure reducing valve, a high-flow-rate and high-flow-rate fluid and a low-flow-rate and low-flow-rate fluid interfere with each other on the downstream side of the valve body 2, and turbulence is generated. The range in which turbulence is generated is indicated by a two-dot chain line a in fig. 12.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2001-255942

Disclosure of Invention

Problems to be solved by the invention

In a pressure reducing valve in which the valve body 2 moves in the valve opening direction when the pressure in the downstream fluid passage 1a decreases as described in patent document 1, when the flow rate of the fluid becomes large, the valve body 2 cannot be moved greatly in the valve opening direction, and there is a problem that the pressure in the downstream fluid passage 1a is likely to decrease. The reason for this is considered to be that turbulence is generated on the downstream side of the valve body 2. That is, if turbulence is generated, the flow velocity of the fluid flowing near the opening of the communication passage 7 decreases, and the effect of sucking the fluid from the communication passage 7 toward the downstream-side fluid passage 1a by the so-called bernoulli negative pressure principle cannot be obtained.

The invention aims to provide a pressure reducing valve which can prevent turbulence from generating at the downstream side of a valve core and improve the flow velocity of fluid.

Means for solving the problems

To achieve the object, a pressure reducing valve of the present invention includes: an actuator that causes a preset pressing force to act; a body having an inlet port into which a fluid supplied from a fluid source flows, an outlet port from which the fluid flowing in from the inlet port flows to the outside, and a fluid passage for communicating the inlet port and the outlet port to allow the fluid to flow; a partition wall provided in the main body and dividing the fluid passage into a primary-side inflow passage and a secondary-side outflow passage; a valve seat provided around a valve opening that communicates the primary-side inflow passage and the secondary-side outflow passage, the valve seat penetrating the partition wall; a valve body having a valve portion that is seated on or separated from the valve seat, the valve body opening and closing the valve opening; a diaphragm that is sandwiched between the actuator and the main body, is stretched in a direction orthogonal to an operation direction of the valve body, and operates the valve body in a direction in which the valve opening is opened by receiving a pressing force from the actuator; a pressure chamber that causes the pressure of the secondary-side outflow passage to act on the diaphragm to operate the valve element in a direction in which the valve opening is closed; and a spring that generates an urging force that urges the valve element in a direction in which the valve opening is closed, wherein the secondary-side outflow passage extends in a direction parallel to an expanding direction of the diaphragm and extends toward the outflow port so as to be orthogonal to an operation direction of the valve element, and the main body includes a suction passage that communicates the secondary-side outflow passage and the pressure chamber, and a thin-plate-shaped partition that divides an interior of the secondary-side outflow passage into a first passage in which the suction passage opens and a second passage on an opposite side.

In the pressure reducing valve of the present invention, a fluid having a relatively high flow rate may flow through the first passage, and a fluid having a relatively low flow rate may flow through the second passage.

In the pressure reducing valve according to the present invention, the spacer may be provided inside a ring fitted to a wall surface of the secondary-side outflow passage, and a through hole connected to the suction passage may be formed in the ring.

In the pressure reducing valve according to the present invention, the cross-sectional shape of the partition may be formed in a wing shape, and the partition may be configured to increase a flow velocity of the fluid flowing through the first passage.

In the pressure reducing valve of the present invention, the suction passage may be located at a position opposite to a maximum thickness position of the spacer.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a pressure reducing valve in which a spacer prevents turbulence from being generated on the downstream side of a valve element, and thus the flow velocity of fluid can be increased.

Drawings

FIG. 1 is a cross-sectional view of a pressure relief valve of the present invention.

Fig. 2 is an enlarged cross-sectional view of a main portion.

Fig. 3 is a perspective view of the partitioning member.

Fig. 4 is a sectional view for explaining a flow path of a fluid.

Fig. 5 is a cross-sectional view showing a modification of the separator.

Fig. 6 is a perspective view of the partitioning member.

Fig. 7 is an enlarged cross-sectional view of the separator.

Fig. 8 is a sectional view for explaining a flow path of a fluid.

Fig. 9 is a cross-sectional view showing a modification of the separator.

Fig. 10 is a cross-sectional view showing a modification of the separator.

Fig. 11 is a graph showing a change in the pressure difference between the fluid passage and the pressure chamber with respect to a change in the fluid flow rate.

Fig. 12 is a sectional view of a conventional pressure reducing valve.

Detailed Description

An embodiment of the pressure reducing valve according to the present invention will be described in detail below with reference to fig. 1 to 11. The pressure reducing valve 11 shown in fig. 1 includes a main body 12 located at a lower side of fig. 1 and an actuator 13 mounted on the main body 12 to apply a predetermined pressing force.

The main body 12 of the present embodiment is composed of a valve housing portion 12a to which the actuator 13 is attached, and a cup-shaped drain bowl 12b located on the opposite side of the actuator 13.

The body 12 has an inlet 14 through which a fluid supplied from a fluid source, not shown, flows in at the right end in fig. 1, and an outlet 15 through which the fluid flowing in through the inlet 14 flows out at the left end in fig. 1. Further, a fluid passage 16 for allowing fluid to flow by communicating between the inlet port 14 and the outlet port 15 is provided in the body 12, and an air inlet port 19 for dividing the fluid passage 16 into a primary inlet passage 17 and a secondary outlet passage 18 is provided. In this embodiment, the air supply port 19 corresponds to a "partition wall" in the present invention.

The air supply port 19 is formed in a cylindrical shape and has a valve opening 21 formed by a through hole communicating the primary-side inflow passage 17 and the secondary-side outflow passage 18 as shown in fig. 2. An annular valve seat 22 is provided around the upstream end of the valve opening 21. A plurality of communication holes 23 extending radially in a direction orthogonal to the valve opening 21 are formed in the air supply port 19. Further, an annular groove 24 extending over the entire circumferential area is formed in the outer circumferential portion of the air supply port 19. A part of the groove 24 is connected to the secondary-side outflow passage 18. The communication hole 23 is formed to extend from the valve opening 21 to the annular groove 24.

A valve body 25 for opening and closing the valve opening 21 is inserted into the valve opening 21. The valve body 25 has a cylindrical shaft portion 25a inserted into the valve opening 21 and a valve portion 25b provided at one end (lower end) of the shaft portion 25a, and is supported so as to be movable in a state of penetrating the air supply port 19. One end (lower end of the valve portion 25 b) of the valve body 25 is biased toward the other end (upper side) by a spring member 26, and the other end (upper end of the shaft portion 25 a) of the valve body 25 is pressed toward one end (lower side) by a pressing force from an actuator 13 described later. When the pressing force from the actuator 13 is smaller than the spring force of the spring member 26, the valve portion 25b of the valve body 25 is seated on the valve seat 22, and when the pressing force from the actuator 13 is larger than the spring force of the spring member 26, the valve portion 25b of the valve body 25 is separated from the valve seat 22.

As shown in fig. 1, a diaphragm 31 is provided at the lower end of the actuator 13 so as to face the shaft portion 25a of the valve body 25. The diaphragm 31 is stretched in a direction orthogonal to the operating direction of the valve body 25 (in the left-right direction in fig. 1), and is sandwiched between the main body 12 and a bonnet 32 of the actuator 13. A pressing member 33 is attached to the center of the diaphragm 31, and the pressing member 33 has a communication passage 33a formed therein, which communicates with the internal space (actuator inner chamber 40) of the bonnet 32 and the pressure chamber 34 surrounded by the diaphragm 31 and the body 12, and an opening 33b of the communication passage 33a on the pressure chamber 34 side is located directly above the upper end of the shaft portion 25a of the valve body 25.

The pressing member 33 and the shaft portion 25a of the valve body 25 are in either a contact state or a separated state as described later, and in a state where the shaft portion 25a of the valve body 25 is in contact with the pressing member 33, the opening 33b of the communication passage 33a on the pressure chamber 34 side is closed by the upper end of the valve shaft 25a, and the communication passage 33a is blocked. On the other hand, in a state where the pressing member 33 is separated from the shaft portion 25a of the valve body 25, the communication passage 33a is opened, and therefore the pressure chamber 34 communicates with the actuator inner chamber 40. Further, a vent hole 39 communicating with the actuator inner chamber 40 and the outside of the actuator 13 is formed in a part of the side wall of the valve cover 32, and when the communication passage 33a of the pressing member 33 is cut, the pressure in the actuator inner chamber 40 is equal to the pressure (atmospheric pressure) outside the actuator 13.

On the other hand, when the communication passage 33a of the pressing member 33 is opened, the fluid in the pressure chamber 34 at a pressure higher than the atmospheric pressure flows into the actuator inner chamber 40 through the communication passage 33a, and is discharged to the outside of the actuator 13 through the exhaust hole 39.

Here, the displacement of the diaphragm 31 is described, and the diaphragm 31 receives a force F1 pressing the diaphragm 31 from the upper surface of the diaphragm 31 on the pressure chamber 34 side and a force F2 pressing the diaphragm 31 from the lower surface of the diaphragm 31 on the actuator inner chamber 40 side, and the direction of the displacement of the diaphragm 31 is determined by the magnitude relationship between the force F1 and the force F2. That is, when the force F1 is larger than the force F2, the center portion of the diaphragm 31 is displaced in a direction away from the main body 12.

The valve body 25 moves in a direction in which the valve portion 25b is seated on the valve seat 22 (i.e., in a direction in which the valve opening 21 is closed) in conjunction with this. Conversely, when the force F1 is smaller than the force F2, the center portion of the diaphragm 31 is displaced in a direction approaching the main body 12. In conjunction with this, the distal end of the shaft portion 25a of the valve body 25 is held in contact with the pressing member 33, and the valve body 25 moves in a direction in which the valve portion 25b is separated from the valve seat 22 (i.e., in a direction in which the valve opening 21 is opened). Thus, the displacement of the diaphragm 31 advances and retreats the valve element 25 in the operating direction to open and close the valve opening 21.

A part of the pressure chamber 34 is formed between the secondary-side outflow passage 18 and the diaphragm 31. The secondary-side outflow passage 18 of this embodiment extends in a direction parallel to the direction in which the diaphragm 31 is stretched, and extends toward the outflow port 15 so as to be orthogonal to the direction in which the valve element 25 operates. A suction pipe 35 formed of a through hole is provided between the pressure chamber 34 in the main body 12 and the secondary-side outflow passage 18. In this embodiment, the suction pipe 35 corresponds to a "suction passage" in the present invention. The suction pipe 35 communicates the pressure chamber 34 with the secondary-side outflow passage 18. Therefore, the fluid is introduced from the secondary-side outflow passage 18 into the pressure chamber 34 through the suction pipe 35. Thus, the pressure of the fluid introduced from the secondary-side outflow passage 18 becomes the pressure in the pressure chamber 34, and the upward pressing force F1 is applied to the diaphragm 31, and as a result, the valve body 25 is operated in the direction of closing the valve opening 21.

The pressing member 33 provided at the center of the diaphragm 31 is biased toward the main body 12 by a pressure adjusting spring 36 made of a compression coil spring housed in the actuator inner chamber 40. The pressure regulating spring 36 is held at one end (lower end) thereof by the pressing member 33, and is disposed between these members in a state where the other end (upper end) thereof presses the pressure regulating spring holder 37 provided to hold the pressure regulating spring 36. One end (lower end) of a pressure adjusting knob 38 screwed to the bonnet 32 abuts on a pressure adjusting spring holder 37, and the pressure adjusting spring holder 37 is held between the pressure adjusting knob 38 and the pressure adjusting spring 36. Thus, the pressure regulating spring 36 held by the pressing member 33 and the pressure regulating spring holder 37 applies a predetermined downward pressing force F2 to the diaphragm 31, and as a result, the valve body 25 is operated in a direction in which the valve opening 21 is opened.

Thus, the upward pressing force F1 and the downward pressing force F2 act on the diaphragm 31, and the operating direction of the valve body 25 is determined by the magnitude relationship between the pressure in the pressure chamber 34 and the spring force of the pressure adjusting spring 36. When the pressure in the pressure chamber 34 is higher than the spring force of the pressure adjusting spring 36, the valve body 25 is operated in the direction in which the valve opening 21 is closed as described above, and as a result, the flow rate of the fluid flowing from the valve opening 21 to the secondary-side outflow passage 18 decreases. On the other hand, when the pressure in the pressure chamber 34 is smaller than the spring force of the pressure adjusting spring 36, the valve body 25 is operated in the direction in which the valve opening 21 is opened, and as a result, the flow rate of the fluid flowing from the valve opening 21 to the secondary-side outflow passage 18 increases.

In the pressure reducing valve 11 of the present embodiment, a partition 41 is provided in the secondary-side outflow passage 18 in order to reduce the pressure in the pressure chamber 34 at a high flow rate.

The partition 41 is formed in a thin plate shape, and as shown in fig. 2, divides the inside of the secondary-side outflow passage 18 into a first passage 42 in which the suction pipe 35 is opened and a second passage 43 on the opposite side. The spacer 41 of this embodiment is formed of a flat plate having a constant thickness, and extends inside the ring 44 in parallel with the axis C (see fig. 2) of the ring 44, as shown in fig. 3. The ring 44 is formed to be fitted to a wall surface of the secondary-side outflow passage 18. The inner peripheral surface 44a of the ring 44 is connected to the inner wall surface 45 of the secondary-side outflow passage 18 located on the upstream side of the ring 44 so as not to form a step.

The ring 44 is provided with a through hole 46 connected to the suction pipe 35. Thus, the substantial opening of the suction pipe 35 extends into the ring 44.

The first passage 42 and the second passage 43 separated by the partition 41 are aligned in the operating direction of the spool 25.

In the pressure reducing valve 11, the valve portion 25b of the valve body 25 is separated from the valve seat 22 to be in an open state, and thus fluid flows as indicated by arrows in fig. 1 and 4. In fig. 4, arrows with thick lines indicate flow paths of fluid flowing at high flow rates and high flow rates, and arrows with thin lines indicate flow paths of fluid flowing at low flow rates and low flow rates. The fluid flowing at a high flow rate and a high flow rate flows through a path having the shortest distance between the inlet (valve seat 22) of the valve opening 21 and the secondary-side outflow passage 18. That is, the fluid flows through one communication passage 23a extending from the valve opening 21 to the secondary-side outflow passage 18. The fluid enters the communication passage 23a from the valve opening 21, changes its flow direction, and flows toward the first passage 42 by inertia. On the other hand, the fluid flowing at a low flow rate and a low flow rate flows from the valve opening 21 into the secondary-side outflow passage 18 through the other communication passage 23b and the annular groove 24. The fluid mainly flows into the second passage 43 to avoid the fluid flowing at a high flow rate and a high flow rate.

Thus, in the pressure reducing valve 11, the fluid flowing at a high flow rate and the fluid flowing at a low flow rate and a low flow rate are separated by the partition 41. Therefore, turbulence can be prevented from being generated on the downstream side of the valve body 25 (the upstream side end of the secondary-side outflow passage 18). When turbulence is less likely to occur in the secondary-side outflow passage 18, the flow velocity of the fluid flowing near the opening of the suction pipe 35 (the opening of the through hole 46) is higher than in the case where turbulence occurs, and therefore, the fluid in the pressure chamber 34 is sucked out into the secondary-side outflow passage 18 by the suction pipe 354 according to the so-called bernoulli negative pressure principle, and the pressure in the pressure chamber 34 is reduced. Hereinafter, the phenomenon of reducing the pressure in the pressure chamber 34 by the bernoulli negative pressure principle will be simply referred to as "straw effect". In this embodiment, the valve opening degree can be relatively increased at the time of a large flow rate by the suction pipe effect, and therefore, the pressure of the secondary-side outflow passage 18 can be reliably prevented from being lowered at the time of a large flow rate.

In the pressure reducing valve 11 of the present embodiment, a fluid having a relatively high flow rate flows through the first passage 42, and a fluid having a relatively low flow rate flows through the second passage 43. Therefore, the suction effect is more remarkable, and the pressure of the secondary-side outflow passage 18 at the time of a large flow rate can be relatively increased.

The separator 41 of this embodiment is provided inside a ring 44 fitted to a wall surface of the secondary-side outflow passage 18. The ring 44 is provided with a through hole 46 connected to the suction pipe 35. Therefore, the partition 41 may be formed separately from the main body 12 and assembled to the main body 12, and thus the pressure reducing valve 11 having the partition 41 may be easily manufactured.

(modification of film sheet)

The diaphragm may be constructed as shown in fig. 5 to 10. In fig. 5 to 10, the same or equivalent members as those described with reference to fig. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

The cross-sectional shape of the partition 51 shown in fig. 5 is formed into an airfoil shape, and as shown in fig. 6, the partition 51 is disposed inside the ring 44. The airfoil shape of the separator 41 is an airfoil shape called a jukowski airfoil. The partition 41 extends with a constant cross-sectional shape from one end to the other end in the radial direction of the ring 44 in a state where the leading edge 51a (see fig. 7) is located on the upstream side so as to increase the flow velocity of the fluid flowing through the first passage 42.

As shown in fig. 7, the chord line 52 connecting the leading edge 51a and the trailing edge 51b of the partition 51 is inclined with respect to the axis C of the ring 44. The direction in which the chord line 52 is inclined with respect to the axis C is a direction in which the first passage 42 gradually widens toward the downstream side in the direction in which the fluid flows. The spacer 41 is configured such that the maximum thickness position 51c thereof faces the through hole 46 of the ring 44. That is, the suction pipe 35 is located at a position opposite to the maximum wing thickness position 51c of the partitioning member 41.

In the pressure reducing valve 11 using the partition 41 of the airfoil shape, the fluid flows along the partition 41 in the first passage 42, so that the flow velocity of the fluid increases. That is, as indicated by a thick line in fig. 8, the fluid having a high flow speed and a high flow rate flowing into the first passage 42 is accelerated in the first passage 42. In fig. 8, the accelerated fluid is indicated by hollow arrows.

When the separator is formed so that the cross-sectional shape thereof is a wing shape, the wing shape can be formed into the shape shown in fig. 9 and 10.

The airfoil shape of the partitioning member 61 shown in fig. 9 is an airfoil shape called a flat-bottom airfoil, and the second passage 43 side is formed substantially flat. The partition 61 is arranged in the ring 44 in such a way that a chord line 62 connecting the leading edge 61a and the trailing edge 61b is parallel to the axis C of the ring 44. The through hole 46 of the ring 44 is provided at a position opposite to the maximum thickness position 61c of the spacer 61.

The airfoil of the partition 63 shown in fig. 10 is an airfoil called a symmetric wing, and is formed symmetrically with a chord line 64 connecting the leading edge 63a and the trailing edge 63b as a center line. In addition, chord line 64 is parallel to axis C of ring 44. The through hole 46 of the ring 44 is provided at a position opposite to the maximum thickness position 63c of the spacer 63.

As shown in fig. 5 to 10, by using the separators 51, 61, 63 having the cross-sectional shape of the airfoil, the separators themselves do not cause turbulence and the flow velocity of the fluid flowing through the first passage 42 can be increased, which complement each other, and a large suction pipe effect can be obtained. Therefore, in this embodiment, the differential pressure between the pressure in the secondary-side outflow passage 18 and the pressure in the pressure chamber 34 can be increased even at a large flow rate, and therefore, the pressure in the secondary-side outflow passage 18 can be reliably prevented from decreasing at a large flow rate.

In the pressure reducing valve 11 having the separators 51, 61, 63 having the cross-sectional airfoil shapes shown in fig. 5 to 10, the suction pipe 35 is located at a position opposite to the maximum thickness positions 51c, 61c, 63 c. Therefore, the suction pipe 35 is opened at a position where the pressure is lowest in the inner wall of the first passage 42, so that the suction pipe effect is maximized.

In the pressure reducing valve 11 using the spacer 41 shown in fig. 1 to 8, the straw effect shown in fig. 11 is obtained. Fig. 11 is a graph showing the volume flow rate of the fluid flowing through the secondary-side outflow passage 18 and the pressure difference between the upstream side and the downstream side of the suction pipe. The pressure difference is a pressure difference between the pressure at the opening of the suction pipe 35 that opens into the first passage 42 and the pressure in the pressure chamber 34. In fig. 11, a solid line indicates a case where the separator 51 having the cross-sectional airfoil shape shown in fig. 5 to 8 is used, and a broken line indicates a case where the separator 41 having the flat plate shape shown in fig. 1 to 4 is used. In addition, the one-dot chain line indicates a case where the diaphragm is not used as a comparative example.

As is clear from fig. 11, the use of the separators 41 and 51 increases the pressure difference due to the straw effect at the time of a large flow rate. Particularly in the case of using the partition 51 of the sectional airfoil shape, the pressure difference significantly increases. When the separators 41 and 51 are not used, it is understood that the pressure in the suction pipe 35 is increased by turbulence generated at the time of a large flow rate, and the opposite effect is obtained.

When the cross-sectional shape of the separator is a wing shape, the shape of the wing shape is not limited to the shape shown in fig. 5 to 10. The shape of the airfoil may be any shape as long as the flow velocity of the fluid in the first passage 42 increases, and the same effect can be obtained regardless of the shape.

Description of the symbols

11 … pressure reducing valve, 12 … main body, 14 … inflow port, 15 … outflow port, 16 … fluid passage, 17 … primary side inflow passage, 18 … secondary side outflow passage, 19 … air supply port (bulkhead), 21 … valve opening, 22 … valve seat, 25 … valve core, 25b … valve part, 31 … diaphragm, 34 … pressure chamber, 35 … suction pipe (suction passage), 36 … pressure regulating spring, 41, 51, 61, 63 … separator, 42 … first passage, 43 … second passage, 44 … ring, 46 … through hole, 51c, 61c, 63c … maximum wing thickness position.