JP2001051727A - Reducing valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reducing valve which can securely restore a function even when secondary pressure considerably drops, which can be miniaturized by miniaturizing an energizing mechanism, and which can secure high changing speed to a secondary side. SOLUTION: The constitution of a valve case 2, a primary port 4, a secondary port 5, a valve chest 10, a movable valve elements 11, a rod insertion hole 12, a valve seat 14, an operation rod 6, an energizing mechanism 7 and a pressure receiving member 8 is provided. Then, a valve element storage chamber 20, a movable small valve element 21, a small diameter rod insertion hole 22, a small diameter valve seat 23, a small diameter rod part 6a and a step part 6b are provided. The movable small valve element 21 can be closed after the movable valve element 11 is closed. The movable small valve element 21 can be opened/closed while the movable valve element 11 is kept closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat valve type pressure reducing valve capable of minimizing a leak amount, and more particularly to a valve capable of reducing a size while increasing a fluid passage.

[0002]

2. Description of the Related Art Conventionally, various types of spool valve type pressure reducing valves have been put to practical use. However, since the pressure reducing valve has a small gap on the outer peripheral side of the spool, the amount of leaking pressure fluid tends to increase, and the fluid pressure is reduced. As the value increases, the amount of leakage also increases. Therefore, recently, a seat valve type pressure reducing valve has been put into practical use.
This type of pressure reducing valve includes a valve case, a valve chamber in the valve case, a rod insertion hole that communicates with the far end of the valve chamber and has a smaller diameter than the valve chamber,
Primary port communicating with valve chamber, 2 communicating with rod insertion hole
A next port, a movable valve body movably housed in the valve chamber, an annular valve seat formed in the back end wall of the valve chamber so as to protrude toward the valve chamber, and a movable valve inserted with a fluid passage in a rod insertion hole. An operation rod that comes into contact with the body, a pressure receiving member that receives the secondary pressure and urges the operation rod toward the valve closing side, and a biasing mechanism that applies a preset elastic force to the operation rod in the valve opening direction is provided. First, the primary pressure introduced into the primary port is reduced and output to the secondary port as a secondary pressure.

In this pressure reducing valve, the primary pressure in the valve chamber acts on the movable valve body, and the movable valve body is pressed against the valve seat. When the secondary pressure is lower than the set pressure, the movable valve element opens and the primary pressure is charged to the secondary side. When the secondary pressure reaches the set pressure, the valve opening force obtained by subtracting the fluid force acting on the pressure receiving member from the urging force of the urging mechanism is used to close the valve acting on the movable valve element due to the difference between the primary pressure and the secondary pressure. It becomes smaller than the valve force, and the movable valve element is closed.
When the secondary pressure subsequently decreases, the valve opening force increases due to a decrease in the fluid force acting on the pressure receiving member. Therefore, the movable valve body is slightly opened, the primary pressure is charged, and the secondary pressure increases, The set pressure is reached again.

[0004] By the way, when the secondary pressure is to be raised, 2
Since the hunting occurs due to the overshoot of the next pressure, Japanese Patent No. 2583986 discloses a technique for preventing the hunting.
In the pressure reducing valve described in the above publication, the hunting is suppressed by switching the fluid passage on the outer peripheral side of the movable valve body to the throttle passage at the end of the transition from the open state to the closed state of the movable valve body. Technology has been proposed.

[0005]

In the state where the secondary pressure is equal to the set pressure and the movable valve body is closed, if the secondary pressure suddenly drops to near atmospheric pressure due to any cause,
The valve closing force for closing the movable valve body by the primary pressure becomes very large. Unless the urging mechanism generates an urging force larger than the valve closing force, the movable valve element cannot be opened, the secondary pressure cannot be raised, and the function of the pressure reducing valve cannot be restored. In order to solve this problem, if the size of the urging mechanism is increased, the pressure reducing valve is increased in size, and the manufacturing cost of the pressure reducing valve is increased.

On the other hand, a small urging mechanism is provided, and a movable valve body,
When the rod insertion hole, operation rod, etc. are formed thin,
The filling speed when filling the actuator with the fluid pressure via the pressure reducing valve is reduced. It is an object of the present invention to provide a pressure reducing valve capable of reliably recovering its function even when the secondary pressure is significantly reduced, and to provide a pressure reducing valve which can be downsized by reducing the size of an urging mechanism. And to provide a pressure reducing valve capable of ensuring a large filling speed for filling into the container.

[0007]

Means for Solving the Problems The pressure reducing valve of claim 1 is
A valve case, a valve chamber in the valve case, a rod insertion hole communicating with a rear end of the valve chamber and having a smaller diameter than the valve chamber, a primary port communicating with the valve chamber, and a secondary port communicating with the rod insertion hole. A port, a movable valve body movably housed in the valve chamber, an annular valve seat formed in the back end wall of the valve chamber so as to protrude toward the valve chamber, and a fluid passage inserted into the rod insertion hole. An operating rod in contact with the movable valve body, a pressure receiving member for receiving a secondary pressure to bias the operating rod toward the valve closing side, and a bias for applying a preset elastic force to the operating rod in a valve opening direction A pressure reducing valve for reducing a primary pressure introduced into a primary port and outputting the same as a secondary pressure to a secondary port, the valve body being formed with the operating rod side end wall left on the movable valve body. An accommodating valve, a movable valve element movably mounted in the valve element accommodating hole and forming a throttle passage on an outer peripheral side; A small-diameter rod insertion hole formed in the side end wall, an annular small-diameter valve seat formed in the rod-side end wall so as to protrude toward the valve body receiving hole, and a small-diameter rod insertion hole formed in the distal end portion of the operation rod. And a stepped portion formed at the starting end of the small-diameter rod portion inserted into the small-diameter rod portion with a gap and capable of contacting the movable valve body.

[0008] The operation of the prerequisite configuration up to "... in the pressure reducing valve" is as described in the section of the prior art, so that the description thereof will not be repeated here and will be related to the characteristic configuration. The operation will be described.

When the fluid pressure is supplied to the primary port and the secondary port to raise the secondary pressure, the movable valve element is opened by the urging force of the urging mechanism, and the primary pressure is charged from the rod insertion hole. Therefore, the flow rate of the fluid is large, and the filling speed is also high. Thereafter, as the secondary pressure approaches the set pressure, the valve opening force for opening the movable valve body with the operating rod decreases, and at the end of the secondary pressure rise, the movable valve body is in the closed state. However, when the primary pressure flowing through the throttle passage on the outer peripheral side of the movable element valve element is charged into the secondary side from the small diameter rod insertion hole while the movable element valve element is opened, and the secondary pressure reaches the set pressure. The mover valve element is also closed. As described above, since the primary pressure is charged into the secondary side through the throttle passage on the outer peripheral side of the movable element valve body, hunting of the secondary pressure at the time of secondary pressure rising can be suppressed.

Next, when the secondary pressure slightly decreases from the set pressure in a state where both the movable valve element and the movable element valve element are closed, the valve opening force of the operation rod increases and the operation rod opens. Move to the side. At this time, before the stepped portion of the operation rod comes into contact with the movable valve body, the small-diameter rod portion opens the movable element valve body and
Since the secondary pressure is charged to the secondary side, the secondary pressure immediately reaches the set pressure, and the movable element valve returns to the closed state. in this way,
The responsiveness of pressure control for adjusting the pressure to the secondary pressure is remarkably improved.

On the other hand, since the small-diameter valve seat, the small-diameter rod portion, and the small-diameter rod insertion hole are much smaller than the valve seat, the operating rod, and the rod insertion hole, the movable element valve can be opened with a small force. . Therefore, even if the secondary pressure drops to near atmospheric pressure in a state where both the movable valve element and the movable element valve element are closed,
Since the valve closing force acting on the mover valve element due to the secondary pressure is relatively small, the movable element valve element is opened with a small biasing force of the biasing mechanism to charge the primary pressure to the secondary side, and then to move large. By opening the valve body, the secondary pressure can be rapidly raised. Thus, it is possible to prevent the function of the pressure reducing valve from being stopped due to a significant decrease in the secondary pressure without increasing the size of the urging mechanism.

A pressure reducing valve according to a second aspect of the present invention is the pressure reducing valve according to the first aspect of the present invention, further comprising a common spring member for elastically biasing the movable element and the movable valve in a valve closing direction. is there. Irrespective of the presence or absence of the primary pressure, the movable valve element can be prevented from detaching from the valve seat, and the movable element valve element can be prevented from detaching from the small diameter valve seat.

According to a third aspect of the present invention, in the pressure reducing valve according to the first or second aspect, the length of the small-diameter rod portion is set to be larger than the total thickness of the operation rod-side end wall of the mover valve body and the valve seat. It is characterized by having. Therefore, the movable valve element can be closed after the movable valve element is closed, or the movable element valve element can be opened while the movable valve element is kept closed.

According to a fourth aspect of the present invention, in the pressure reducing valve according to any one of the first to third aspects, a valve surface portion of the movable valve body facing the valve seat is formed of a synthetic resin member, and faces the small diameter valve seat. The valve face of the mover valve body is made of a synthetic resin member. When the movable valve body is in the closed state, the valve surface portion made of the synthetic resin member is in pressure contact with the valve seat, so that no fluid pressure leak occurs. Similarly, when the movable element valve is in the closed state, the valve surface portion made of the synthetic resin member is pressed against the small-diameter valve seat, so that no fluid pressure leak occurs.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example in which the present invention is applied to a pressure reducing valve that reduces the hydraulic pressure. As shown in FIGS. 1 and 2, the seat valve type pressure reducing valve 1
Valve case 2 and pressure reducing valve mechanism 3 installed in valve case 2
A primary port 4 for introducing a primary pressure to the pressure reducing valve mechanism 3,
A secondary port 5 for discharging the reduced secondary pressure, an operating rod 6 for opening the pressure reducing valve mechanism 3, and an operating rod 6 for applying a preset elastic biasing force in the valve opening direction (right direction in FIG. 1). And a pressure receiving member 8 that receives the secondary pressure of the secondary port 5 and urges the operating rod 6 in the valve closing direction (left direction in FIG. 1).

The pressure reducing valve 1 reduces the primary pressure supplied to the primary port 4 to a preset secondary pressure and outputs the reduced pressure to the secondary port 5. The valve case 2 has a case main body 2a, a case auxiliary body 2b that forms the valve seat 14 of the pressure reducing valve mechanism 3, and the valve chamber 10, and the case auxiliary body 2b is fixed to the case main body 2a. A seal member 7 is attached to an outer peripheral portion of the seal member.

The pressure reducing valve mechanism 3 will be described. The pressure reducing valve mechanism 3 has a structure in which a main pressure reducing mechanism and a sub pressure reducing mechanism are concentrically arranged. The main pressure reducing mechanism communicates concentrically with the valve chamber 10 communicating with the primary port 4, the movable valve body 11 movably accommodated in the valve chamber 10 in the axial direction (left-right direction), and the back end of the valve chamber 10. A rod insertion hole 12 having a diameter smaller than that of the valve chamber 10, an operating rod 6 inserted from the left with an annular oil passage 13 in the rod insertion hole 12, and a rod insertion hole in a rear end wall of the valve chamber 10. An annular valve seat 14 and the like are formed on the edge of the end of the valve 12 so as to protrude toward the valve chamber 10.

The movable valve body 11 is movably mounted in the valve chamber 10 in the axial direction. Movable valve element 1 facing valve seat 14
The valve face 1 is formed of a sealing member 11a made of a synthetic resin material (for example, nylon). Therefore, in the valve closed state, the sealing member 11a is in pressure contact with the protruding valve seat 14, so that no hydraulic leak occurs. A plurality of passage grooves through which a sufficient amount of oil can pass are formed in the outer peripheral portion of the movable valve body 11 in the axial direction. The rod insertion hole 12 communicates with the secondary port 5 via the cylinder hole 15. The operation rod 6 is inserted into the rod insertion hole 12 with an annular oil passage 13 having a relatively large cross-sectional area. The operating rod 6 is located at the start end position of the small diameter rod portion 6a and has a movable valve body 1
1, a stepped portion 6b that can be contacted from the left is formed, and the stepped portion 6b contacts the movable valve body 11 from the left.

The auxiliary pressure reducing mechanism includes a valve housing hole 20 formed in the movable valve body 11 with the operation rod side end wall 11b left, and a movable valve mounted movably in the axial direction in the valve housing hole 20. A body 21, a small-diameter rod insertion hole 22 formed in the operation rod side end wall 11 b and having a diameter significantly smaller than the rod insertion hole 12;
The small-diameter rod portion 6 inserted into the small-diameter rod insertion hole 22
a, small diameter rod insertion hole 2 in operation rod side end wall 11b
An annular small-diameter valve seat 23 formed at the edge of the end portion 2 so as to protrude toward the valve housing hole 20, a movable valve body 21 and a movable valve body 11.
And a small coil spring 24 for urging both in the valve closing direction (leftward). The left end of the coil spring 24 is
The right end of the coil spring 24 is received by a spring receiving member 25 and a stop ring 26 in the right end of the case auxiliary body 2b.

The mover valve element 21 is axially movably mounted in the valve element housing hole 20 with a cylindrical throttle passage 20a on the outer peripheral side. The valve face of the mover valve body 21 facing the small-diameter valve seat 23 is made of a synthetic resin material (for example, nylon).
It is comprised by the sealing member 21a made from. Therefore, in the valve closed state, the sealing member 21a is in pressure contact with the protruding small-diameter valve seat 23, so that no hydraulic leak occurs.

The small-diameter rod portion 6a formed at the tip of the operating rod 6 is inserted into the small-diameter rod insertion hole 22 with an annular gap. The length of the small diameter rod portion 6a is set to be larger than the total thickness of the operation rod side end wall 11b and the valve seat 14. Therefore, the movable valve element 21 can be opened while the movable valve element 11 is closed. That is,
At the end of the secondary pressure rise, the main pressure reducing mechanism closes first,
Thereafter, the auxiliary pressure reducing mechanism closes. In a state where the secondary pressure is almost filled, the secondary pressure reducing mechanism is opened and closed while the main pressure reducing mechanism is maintained in the valve closed state, and pressure adjustment is performed to maintain the secondary pressure at the set pressure.

The primary port 4 is provided with a wire mesh filter 30, and this filter 30 is fixed by a metal fitting 31 screwed to the case body 2a. A plurality of passages are also formed in the holding portion 31 a of the metal fitting 31 in an auxiliary manner, and the primary pressure supplied to the primary port 4 passes through the filter 30 and passes through the valve chamber 1.
0 is introduced. The secondary port 5 is provided with a wire mesh filter 32, and the filter 32 is fixed by a metal fitting 33 screwed to the case body 2a.

A cylinder hole 15 is formed in the left half of the case body 2a in series with the rod insertion hole 12 and has a larger diameter than the rod insertion hole 12. The rod insertion hole is formed through the cylinder hole 15. 12 communicates with the secondary port 5. A pressure receiving member 8 (piston) integrated with the operation rod 6 is slidably mounted on the left half of the cylinder hole 15 in an oil-tight manner. The pressure receiving member 8 is fixed to the output plate 41 of the urging mechanism 7. .

The urging mechanism 7 will be described. Biasing mechanism 7
Are a case member 40, an axially movable output plate 41, an axially movable adjustment plate 42, a strong compression coil spring 43 mounted therebetween, and an adjustment for adjusting the position of the adjustment plate 42. It is composed of bolts 44 and nuts 45 and the like. The case member 40 includes a cylindrical member 40a and four
And an end plate 40b fixed by bolts 46. 1 shows a state in which the main pressure reducing mechanism and the sub pressure reducing mechanism are fully opened, and in this state, the output plate 41 is connected to the case body 2.
a, but the output plate 41 moves in the axial direction integrally with the operation rod 6.

The secondary pressure can be adjusted by adjusting the position of the adjusting plate 42 via the adjusting bolt 44 and the nut 45 and adjusting the elastic biasing force of the compression coil spring 43. For example, if the elastic urging force of the compression coil spring 43 is strengthened, the secondary pressure increases. The elastic urging force of the compression coil spring 43 is adjusted according to the values of the primary pressure and the secondary pressure, the diameter of the valve seat 14, the diameter of the small diameter valve seat 23, the pressure receiving area of the pressure receiving member 8, and the like.
It is configured to generate a preset secondary pressure.

Next, the operation of the pressure reducing valve 1 described above will be described. When the hydraulic pressure is supplied to the primary port 4 and the secondary port 5 to raise the secondary pressure, as shown in FIG. 1, both the movable valve element 11 and the movable element valve 21 are opened, and Since the next pressure is filled from the rod insertion hole 12, the oil flow rate is large and the filling speed is high. Thereafter, as the secondary pressure approaches the set pressure, the valve-opening force for opening the movable valve element 11 with the operating rod 6 decreases, and at the end of the secondary pressure rising, the movable valve moves as shown in FIG. The valve body 11 is in the valve closed state.

Then, while the mover valve element 21 is open,
The primary pressure flowing through the throttle passage 20a on the outer peripheral side of the movable valve element 21 is charged from the small-diameter rod insertion hole 22 to the secondary side (see FIG. 3). 21
Are also closed (see FIG. 4). In this way, the secondary side is filled through the throttle passage 20a on the outer peripheral side of the mover valve element 21, so that the secondary pressure hunting can be effectively suppressed when the secondary pressure rises.

Next, as shown in FIG. 4, when the secondary pressure slightly decreases from the set pressure in a state where both the movable valve element 11 and the movable element valve element 21 are closed, the operation rod 6 is opened. The force increases and the operating rod 6 moves to the valve opening side. At this time, before the stepped portion 6b of the operation rod 6 comes into contact with the movable valve body 11, as shown in FIG. 3, the small diameter rod portion 6a opens the movable element valve body 21 to reduce the primary pressure to the secondary pressure. To fill the port,
The secondary pressure immediately reaches the set pressure, and thereafter, the mover valve element 21 returns to the closed state (see FIG. 1). Thus, the responsiveness of the pressure control for generating and maintaining the secondary pressure is remarkably improved.

On the other hand, as compared with the valve seat 14, the operating rod 6, and the rod insertion hole 12, the small-diameter valve seat 23, the small-diameter rod portion 6
a, Since the small-diameter rod insertion hole 22 is extremely small, the movable valve element 21 can be opened with a small force. Therefore, even when the secondary pressure decreases to near atmospheric pressure in a state where both the movable valve element 11 and the movable element valve 21 are closed, the valve closing force acting on the movable element valve 21 by the primary pressure is still small. Because it is small, the urging mechanism 7
By opening the mover valve element 21 with a small urging force, the hydraulic pressure on the primary side can be charged to the secondary side. Since the valve closing force acting on the movable valve body 11 decreases due to the increase in the secondary pressure, the movable valve body 11 opens and the pressure reducing valve 1 starts functioning normally, so that the function of the pressure reducing valve 1 does not stop. . In addition, since a common spring member for elastically biasing the movable valve element and the movable valve element in the valve closing direction is provided, the movable valve element is detached from the valve seat, and the movable element valve element is detached from the small diameter valve seat. Can be prevented.

Next, a modified example in which the pressure reducing valve 1 is partially changed will be described. First, a spring member for biasing the movable valve body 11 can be provided independently of the coil spring 24. Further, the case auxiliary body 2b is not essential, and the part of the case auxiliary body 2b may be constituted by the case main body 2a.

There is no problem even if the position, orientation, size, etc. of the primary port 4 and the secondary port 5 are appropriately changed.
Moreover, since the metal fittings 31 and 33 are provided for fixing the filters 30 and 32, the metal fittings 31 and 33 are
It can be omitted together with 0 and 32. Also, the urging mechanism 7
Is not limited to a configuration in which the biasing force is generated by the compression coil spring 43, but may be a configuration in which the biasing force is generated by hydraulic pressure, pneumatic pressure, or hydraulic pressure and a spring member. Although the pressure reducing valve 1 has been described as an example of a pressure reducing valve that reduces the oil pressure, the pressure reducing valve of the present invention is also applied to various pressures other than the oil pressure, or a pressure reducing valve that reduces the air pressure or other gas pressures. The same can be applied. In addition, various modifications can be made to the pressure reducing valve 1 without departing from the spirit of the present invention.

[0032]

According to the pressure reducing valve of the first aspect, even when the secondary pressure is extremely reduced while the movable valve element and the movable element valve element are closed, a relatively small urging mechanism is used. The primary pressure can be charged to the secondary side by opening the movable element valve. When the secondary pressure is increased to a certain extent, the movable valve element opens and the primary pressure can be rapidly charged to the secondary side. That is, it is possible to prevent the function stop of the pressure reducing valve due to the extreme decrease in the secondary pressure, and it is not necessary to increase the size of the urging mechanism in order to prevent the function stop. Can be reduced in size. In addition, since it is not necessary to reduce the size of the movable valve body and the valve seat in order to prevent the function of the pressure reducing valve from being stopped, it is possible to secure a high filling speed when filling the secondary pressure.

At the end of the rise of the secondary pressure, the primary pressure is charged into the secondary side through the throttle passage on the outer peripheral side of the mover valve body, so that the hunting during the rise of the secondary pressure is performed. Can be suppressed. In addition, when maintaining the secondary pressure, the secondary pressure can be adjusted by opening and closing the movable element that is sensitive to a decrease in the secondary pressure while keeping the movable valve closed. Excellent pressure control response.

According to the pressure reducing valve of the second aspect, since the common spring member is provided to elastically urge the movable element valve element and the movable valve element in the valve closing direction, the movable valve element is provided regardless of the presence or absence of the primary pressure. Can be prevented from detaching from the valve seat, and the movable element valve can be prevented from detaching from the small-diameter valve seat.

According to the pressure reducing valve of the third aspect, the length of the small diameter rod portion is set to be larger than the total thickness of the operation rod side end wall of the movable valve element and the valve seat. The movable valve element can be reliably opened with the valve closed.

According to the pressure reducing valve of the fourth aspect, the valve surface of the movable valve body facing the valve seat is made of a synthetic resin member, and the valve surface of the movable valve body facing the small diameter valve seat is made of a synthetic resin member. The fluid pressure does not leak from between the movable valve element and the valve seat, and similarly, the fluid pressure does not leak from between the movable element valve element and the small diameter valve seat.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a pressure reducing valve according to an embodiment of the present invention.

FIG. 2 is a plan view of the pressure reducing valve of FIG. 1;

FIG. 3 is a sectional view of a main part of the pressure reducing valve in an operating state in which a main pressure reducing mechanism is closed and a sub pressure reducing mechanism is opened.

FIG. 4 is a sectional view of a main part of the pressure reducing valve in an operating state in which both a main pressure reducing mechanism and a sub pressure reducing mechanism are closed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure reducing valve 2 Valve case 4 Primary port 5 Secondary port 6 Operation rod 6a Small diameter rod part 6b Stepped part 7 Biasing mechanism 8 Pressure receiving member 10 Valve room 11 Movable valve element 11a Sealing member 11b Rod side end wall part 12 Rod insertion hole 13 Oil passage 14 Valve seat 20 Valve housing hole 20a Restrictor passage 21 Mover element 21a Sealing member 22 Small diameter rod insertion hole 23 Small diameter valve seat 24 Coil spring

Claims (4)

[Claims] 1. A valve case, a valve chamber in the valve case, a rod insertion hole communicating with a rear end of the valve chamber and having a smaller diameter than the valve chamber, a primary port communicating with the valve chamber, and a rod insertion hole. , A movable valve body movably housed in the valve chamber, an annular valve seat formed in the rear end wall of the valve chamber so as to protrude toward the valve chamber, and a fluid passage in the rod insertion hole. An operating rod inserted with a gap between the operating rod and the movable valve body, a pressure receiving member for receiving a secondary pressure to urge the operating rod toward the valve closing side, and a preset elastic force applied to the operating rod in a valve opening direction. A pressure reducing valve for reducing the primary pressure introduced into the primary port and outputting the reduced secondary pressure as a secondary pressure to the secondary port. A formed valve element receiving hole, and a movable valve element movably mounted in the valve element receiving hole and forming a throttle passage on an outer peripheral side. A small-diameter rod insertion hole formed in the operation rod-side end wall and an annular small-diameter valve seat formed in the rod-side end wall so as to protrude toward the valve body housing hole; and a small diameter formed in a distal end portion of the operation rod. A pressure reducing valve, comprising: a small-diameter rod portion inserted into the rod insertion hole with a gap; and a stepped portion formed at a starting end position of the small-diameter rod portion and capable of contacting a movable valve body. 2. The pressure reducing valve according to claim 1, further comprising a common spring member for elastically biasing the movable element and the movable valve in a valve closing direction. 3. The length of the small-diameter rod portion is set to be larger than the total thickness of the operation rod-side end wall of the mover valve body and the valve seat. Pressure reducing valve. 4. The valve face of the movable valve body facing the valve seat is formed of a synthetic resin member, and the valve face of the movable valve body facing the small diameter valve seat is formed of a synthetic resin member. The pressure reducing valve according to claim 1, wherein