JP7216497B2 - Pressure reducing valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pressure reducing valve for reducing the pressure of a fluid having a primary pressure to a secondary pressure.

Conventionally, there has been known a pressure reducing valve that reduces the pressure of a fluid having a primary pressure to a secondary pressure. For example, a pressure-reducing valve disclosed in Patent Document 1 has a primary chamber into which fluid flows from a primary-side pipeline, which communicates with the primary chamber through a communication hole, and allows the fluid to flow out to a secondary-side pipeline. and a secondary chamber (referred to as a housing main body in Patent Document 1).

The casing is provided with a primary side port member that is connected to a fuel gas pipeline through which primary pressure fluid flows and that forms a primary side port. Although not shown in Patent Document 1, a seal member (high-pressure seal member) that suppresses leakage of the primary pressure fluid is presumably provided between the primary side port member and the casing. A sealing member (low-pressure sealing member) is provided between the casing and the cover to suppress leakage of secondary pressure fluid.

JP 2010-244362 A

However, in the casing of the conventional pressure reducing valve, there is a portion through which the primary pressure fluid passes, that is, a portion on which the primary pressure fluid acts, so that the casing is required to be strong. However, from the viewpoint of reducing the material cost of the casing, it is difficult to produce a thin and thick casing using a high-strength and high-cost material. Therefore, the thickness of the casing is increased by using low-cost materials to meet the cost reduction. As a result, the overall size of the pressure reducing valve tends to increase.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a pressure reducing valve that does not cause the high pressure primary pressure fluid to act on the casing and that does not increase the size of the pressure reducing valve.

A pressure reducing valve of the present invention is a pressure reducing valve that reduces the pressure of a primary pressure fluid flowing in from an external pipe to a secondary pressure, and comprises a primary side passage communicating with the external pipe and a downstream side of the primary side passage. a valve seat portion formed thereon; a valve body that moves between a closed position seated on the valve seat portion and an open position spaced apart from the valve seat portion; a secondary passage; a casing having a valve body space formed between the primary side passage and the secondary side passage and in which the valve body is disposed; and a secondary pressure seal member provided between the casing and the seat piece. It is equipped.

According to the present invention, the casing is not required to have a high strength because the casing has no portion on which the primary pressure fluid acts. Therefore, since there is no need to increase the thickness of the casing, the overall size of the pressure reducing valve does not increase.

In the above invention, the seat piece has a pipe connection portion formed on the upstream side of the primary passage, and an external pipe is connected to the pipe connection portion of the seat piece to reduce the primary pressure. It is desirable to prevent fluid leakage.

According to the above configuration, leakage of primary pressure fluid is prevented without requiring a primary pressure seal member (high pressure seal member) at the pipe connection portion.

In the above invention, the seat piece includes a recessed seat main body portion formed with the pipe connection portion connected to the external pipe at the inner bottom portion, and the external pipe communicates with the primary side passage. A pipe portion provided with a pipe passage, and a tubular portion into which the seat main body is inserted and screwed are provided, and the seat main body is inserted into and screwed into the tubular portion of the external pipe. It is desirable that the downstream end of the pipe portion is pressed against the pipe connection portion of the seat body portion.

According to the above configuration, there is no need to provide a primary pressure seal member (high pressure seal member) for suppressing leakage of the primary pressure fluid. This eliminates the risk of fluid leakage when using high pressure seals. In addition, a metal seal is realized by pressing the downstream end of the pipe portion against the pipe connecting portion at the bottom of the seat body portion while the seat body portion is inserted into and screwed to the tubular portion of the external pipe. there is Furthermore, the number of parts can be reduced as compared with an embodiment in which a filter, which will be described later, is provided.

In the above invention, the pressure reducing valve includes a filter provided in the primary side passage of the seat piece, and a connecting passage whose upstream end constitutes a connecting portion with the external pipe and whose downstream end communicates with the primary side passage of the seat piece. and a primary pressure seal member provided between the seat piece and the inlet housing.

According to the above configuration, the number of parts increases compared to the above-described mode in which no filter is provided, and a primary pressure sealing member (high pressure sealing member) is required between the seat piece and the inlet housing, but the filter can be incorporated. can be done. This makes it possible to deal with external piping that is not provided with a filter.

In the above invention, the inlet housing has a pipe connection portion formed upstream of the connection passage, and the external pipe and the pipe connection portion of the inlet housing are connected to each other so that the primary pressure fluid is discharged. should be prevented from leaking out.

According to the above configuration, leakage of primary pressure fluid is prevented without requiring a primary pressure seal member (high pressure seal member) at the pipe connection portion.

In the above invention, the inlet housing has a concave inlet main body portion formed with the pipe connecting portion connected to the external pipe at the inner bottom portion, and the external pipe communicates with the connection passage. A pipe portion provided with a passage and a tubular portion into which the inlet main body is inserted and screwed are provided, and the inlet main body is inserted into and screwed into the tubular portion of the external pipe. It is desirable that the downstream end of the pipe portion is pressed against the pipe connection portion of the inlet body portion.

According to the above configuration, the downstream end of the pipe portion is pressed against the pipe connection portion of the inlet body portion in a state where the inlet body portion is inserted into and screwed to the cylindrical portion of the external pipe, thereby realizing a metal seal. It is

ADVANTAGE OF THE INVENTION According to this invention, the fluid of primary pressure which is a high pressure does not act on a casing, and can provide the pressure-reduction valve which does not become large-sized.

1 is a cross-sectional view showing a pressure reducing valve according to a first embodiment of the invention; FIG. FIG. 5 is a cross-sectional view showing a pressure reducing valve according to a second embodiment of the present invention;

A pressure reducing valve according to an embodiment of the present invention will be described below with reference to the drawings. The pressure reducing valve described below is merely one embodiment of the present invention. Accordingly, the present invention is not limited to the following embodiments, and additions, deletions, and modifications can be made without departing from the scope of the present invention.

(First embodiment)
The pressure reducing valve 1 according to the present embodiment is a valve device used for reducing the pressure of a fluid such as a high pressure gas to a working pressure or atmospheric pressure. It is used by interposing it in a discharge channel or the like connected to. As shown in FIG. 1, the pressure reducing valve 1 includes a casing 2, a valve body 3, a tubular reinforcing body 4, a rolling bearing 5, a spring member 6, a cover 12, a holder 13, and a seat piece 65. It has However, the fluid may be liquid.

An insertion hole 14 and a secondary passage 41 are formed in the casing 2 . Further, a seat piece 65 having a primary side passage 15 formed vertically about the axis L1 of the pressure reducing valve 1 is attached to the casing 2 . explain in detail. The casing 2 is provided with a hole 50 formed around the axis L1. The hole portion 50 communicates with the later-described valve body space 24 .

The seat piece 65 has a joint portion 60 which is inserted into a hole portion 50 of the casing 2 and joined to protrude upward from a seat body portion 62 described later, and a flange portion 66 extending in the horizontal direction, and has a concave cross section. and a seat main body portion 62 formed in a concave shape (downwardly in FIG. 1). In other words, the seat body portion 62 is formed in a bottomed tubular shape and has a tubular portion 67 and an inner bottom portion 67a. A primary side passage 15 is formed along the vertical direction centering on the axis L1 across the joint portion 60 of the seat piece 65 and the seat main body portion 62 having such a configuration. An opening at the upstream end of the primary passage 15 constitutes a pipe connection portion (primary port) 16 to which an external pipe 75 is connected. The seat piece 65 is attached to the casing 2 by fixing the flange portion 66 to the casing 2 with bolts 68 . The outer peripheral surface of the flange portion 66 and the outer peripheral surface of the casing 2 are substantially flush with each other.

The external pipe 75 is a pipe portion 70 having a pipe passage 71 through which a primary pressure (high pressure) fluid flows, and whose downstream end is connected to the pipe connection portion 16 of the seat piece 65, and a concave cross-sectional shape that holds the pipe portion 70. and a holding portion 74 of. In other words, the holding portion 74 has the cylindrical portion 72 and the bottom portion 73 that holds the cylindrical portion 72 . An insertion hole 73a is formed around the axis L1 in the bottom portion 73 of the holding portion 74, and the pipe portion 70 is inserted into the insertion hole 73a. Further, the tip of the pipe portion 70 is formed in a hemispherical shape, and the downstream end of the pipe passage 71 communicates with the pipe connection portion 16 . The cylindrical portion 67 of the seat body portion 62 is inserted into and screwed with the cylindrical portion 72 of the external pipe 75 . In this manner, the tubular portion 67 of the seat body portion 62 is inserted into and screwed into the tubular portion 72 of the external pipe 75, and the downstream end (tip) of the pipe portion 70 is connected to the inner bottom portion 67a of the seat body portion 62. A metal seal is realized by being pressed, and the piping passage 71 and the primary side passage 15 are communicated with each other in a state in which the metal seal is formed.

A first sealing member (secondary pressure sealing member) 63 is provided between the casing 2 and the seat piece 65 to suppress leakage of secondary pressure fluid. Specifically, a seal groove 64 is formed on the outer peripheral surface of the joint portion 60 of the sheet piece 65 along the entire circumference. A first seal member 63 such as an O-ring is fitted in the seal groove 64 . The first seal member 63 seals between the joint portion 60 of the sheet piece 65 and the inner peripheral surface of the hole portion 50 of the casing 2 . As a result, the secondary pressure fluid in the valve body space 24 is suppressed from leaking to the outside.

The insertion hole 14 of the casing 2 is formed downward from the upper surface of the recess 11a, which will be described later, and has an opening 14a in the upper surface. The insertion hole 14 is a hole with a bottom, and a secondary side passage 41 is formed in a side wall portion defining the insertion hole 14 . The primary side passage 15 formed in the seat piece 65 is connected to the piping connection portion 16 into which the fluid flows. The secondary passage 41 is formed radially outwardly away from the primary passage 15 and extends horizontally. The secondary passage 41 is connected to the secondary port 42 . An annular recess 11a is formed around the opening 14a of the casing 2. As shown in FIG. An annular stepped portion 11b positioned higher than the recess 11a is formed in the radially outer portion of the recess 11a. A cover 12 is provided on the stepped portion 11b so as to cover the opening 14a.

The cover 12 is formed in a cylindrical shape with a bottom, and is opened downward. The cover 12 is formed such that its inner diameter substantially matches the diameter of the recess 11 a of the casing 2 . A flange 12b extending radially outward is formed on the open end 12a of the cover 12 along the entire circumference. The flange 12b is placed on the stepped portion 11b of the casing 2 and fixed to the casing 2 by fastening members such as bolts (not shown). The cover 12 is provided on the casing 2 so as to cover the valve body 3 and a holder 13 which will be described later.

The holder 13 is formed in a cylindrical shape, and its tip portion 13a is inserted into the insertion hole 14 and screwed. The holder 13 holds the valve body 3 so that the valve body 3 can slide along the axis L1. The holder 13 is provided with a flange 13b extending radially outward from the insertion hole 14 at its intermediate portion and integral with the holder 13 . The flange 13b is formed such that its outer diameter substantially matches the diameter of the recess 11a of the casing 2, and a portion of the flange 13b is fitted into the recess 11a. The upper portion of the flange 13b protrudes upward, and is fitted to the cover 12 so that the outer peripheral surface of the upper portion contacts the inner peripheral surface of the cover 12. As shown in FIG. The holder 13 has a through hole extending vertically about the axis L1, and the valve body 3 is inserted through the through hole so as to reciprocate vertically.

The valve body 3 is made of a soft material such as an aluminum alloy and has a cylindrical shape. A base portion 3 a of the valve body 3 protrudes radially outward from the rest of the valve body 3 . The remaining portion of the valve body 3 is inserted into the holder 13, and the tip portion 3b of the valve body 3 protrudes further downward from the tip portion 13a of the holder 13. As shown in FIG. A valve body space 24 is formed around the valve body 3 and below the valve body 3 with the holder 13 inserted into the insertion hole 14 and the valve body 3 inserted into the holder 13 . The tip portion 3b is arranged to face the downstream end of the primary passage 15, and an annular valve seat portion 20 is formed around this downstream end. Further, the valve body 3 has a seat portion 21 at the tip portion 3 b facing the valve seat portion 20 . The seat portion 21 of the valve body 3 moves between a closed position where it is seated on the valve seat portion 20 and an open position where it is separated from the valve seat portion 20 . An orifice 22 is formed between the seat portion 21 and the valve seat portion 20 when the seat portion 21 is in the open position, and the orifice 22 reduces the pressure of the high pressure fluid from the primary side passage 15 . .

A cylindrical reinforcing body 4 called a bush is attached to the intermediate portion of the valve body 3 . The tubular reinforcing member 4 is a thin cylindrical member made of a material harder than the material of the valve body 3, such as a chromium molybdenum steel material subjected to gas carburizing and quenching. The cylindrical reinforcing body 4 is fitted and fixed around the valve body 3 by press-fitting it into the intermediate portion of the valve body 3 . It should be noted that the exterior method is not limited to press-fitting. The intermediate portion of the valve body 3 is reinforced by attaching a cylindrical reinforcing body 4, and is inserted into the holder 13 with the cylindrical reinforcing body 4 attached. Further, the holder 13 is formed with a bearing housing space 25 which is a substantially cylindrical space around the intermediate portion of the valve body 3 . Specifically, the inner peripheral surface of the holder 13 has an inwardly directed flange 13c formed over the entire circumference in its intermediate portion, and the intermediate portion protrudes radially inward compared to the remaining portion. there is As a result, a substantially cylindrical bearing housing space 25 is formed between the holder 13 and the valve body 3 on the base end side of the holder 13, and the rolling bearing 5 is housed in the bearing housing space 25. ing.

The rolling bearing 5 is a so-called direct-acting ball guide, and has a substantially cylindrical shape. The rolling bearing 5 is fitted and fixed to the inner peripheral portion of the holder 13 so as to be accommodated in the bearing accommodation space 25 . Further, the valve body 3 is inserted through the rolling bearing 5 with a cylindrical reinforcing body 4 interposed therebetween. That is, the rolling bearing 5 is covered with a cylindrical reinforcing body 4 attached to the intermediate portion of the valve body 3 . As a result, the valve body 3 is supported by the rolling bearing 5 via the cylindrical reinforcing body 4, and can smoothly reciprocate vertically along the axis L1. Conventionally, since the ball 5a of the rolling bearing 5 is brought into contact with the surface of the valve body 3 and the valve body 3 is directly supported by the rolling bearing 5, the surface of the base material of the valve body 3 made of a soft material is plated. It has been treated to harden it. However, the base material of the valve body 3 may not be able to withstand the surface pressure received from the ball 5a of the rolling bearing 5 and may be dented, or the base material may be damaged due to peeling of the plated layer formed on the surface. By interposing the cylindrical reinforcing body 4, the balls 5a of the rolling bearing 5 can roll on the outer surface of the cylindrical reinforcing body 4, and the surface pressure of the balls 5a is reduced by the cylindrical reinforcing body 4 made of a hard material. Can receive. Therefore, deformation of the base material of the valve body 3 can be suppressed, and the durability of the valve body 3 can be improved.

In this manner, the intermediate portion of the valve body 3 is supported by the rolling bearing 5 via the cylindrical reinforcing body 4 so as to be able to reciprocate. Further, in the valve body 3, a tip side portion 3c, which is a portion (excluding the tip portion 3b) on the tip side from the cylindrical reinforcing body 4, is inserted through a hole formed by the inward flange 13c of the holder 13. . A seal groove 26 is formed on the outer peripheral surface of the distal end portion 3c of the valve body 3 along the entire circumference.

A valve body seal 27 such as an O-ring is fitted in the seal groove 26 . The valve body seal 27 abuts against the inward flange 13c to seal the space between the distal end portion 3c and the inward flange 13c. As a result, the distal end portion 3c of the valve body 3 is inserted through the inward flange 13c in a sealed state and is guided by the inward flange 13c so as to move along the axis L1.

A base portion 3a, which is a portion of the valve body 3 closer to the base end than the tubular reinforcing member 4, protrudes outward from the holder 13, and its outer diameter substantially matches the inner diameter of the cover 12. As shown in FIG. Therefore, the outer peripheral surface of the base portion 3a faces the inner peripheral surface of the cover 12, and a seal groove 28 is formed in the outer peripheral surface of the base portion 3a over the entire circumference in the circumferential direction. A valve body seal 29 , such as an O-ring, is fitted in the seal groove 28 , and the valve body seal 29 abuts against the inner peripheral surface of the cover 12 to provide a seal between the base portion 3 a of the valve body 3 and the cover 12 . is sealed. As a result, the base portion 3a of the valve body 3 is fitted in the inner peripheral surface of the cover 12 in a sealed state, and is guided by the cover 12 so as to reciprocate along the axis L1.

A base portion 3a of the valve body 3 is formed with a spring receiving portion 3d. The spring receiving portion 3d is formed on the outer peripheral edge portion of the lower surface of the base portion 3a and arranged to face the upper surface of the flange 13b of the holder 13. As shown in FIG. A cylindrical spring housing space 30 surrounded by the holder 13 and the cover 12 is formed between the spring receiving portion 3d and the flange 13b, and the spring member 6 is housed in the spring housing space 30. . The spring member 6 is, for example, a compression coil spring, and the upper and lower ends of the spring member 6 are supported by the spring receiving portion 3d of the base portion 3a and the spring receiving portion 13d, which is the upper surface of the holder 13, respectively. Also, the spring member 6 is housed in the spring housing space 30 in a compressed state, and biases the valve body 3 toward the open position. Further, a secondary pressure acts on the valve body 3 against the biasing force of the spring member 6 (that is, to move the valve body 3 toward the closed position). A recess 31 is formed in the base portion 3a of the valve body 3 to receive pressure.

The recess 31 is formed in the base portion 3a of the valve body 3 and extends along the axis L1. The recess 31 opens toward the ceiling portion 12c of the cover 12, and a secondary pressure chamber 32 including the recess 31 is formed between the base portion 3a of the valve body 3 and the ceiling portion 12c of the cover 12. It is The secondary pressure chamber 32 is isolated from the spring housing space 30 by the valve body seal 29 and is connected to the valve body space 24 through the communication hole 33 of the valve body 3 .

The communication hole 33 is composed of a communication portion 33a and a connection portion 33b. The communication portion 33a extends from the bottom defining the recess 31 toward the tip portion 3b of the valve body 3 along the axis L1. The distal end of the communicating portion 33a extends to the front of the distal end portion 3b and is connected to the connecting portion 33b. The connecting portion 33b extends radially through the valve body 3 . A portion closer to the tip portion 3b than the tip portion 3c of the valve body 3 is formed to have a diameter smaller than that of the tip portion 3c. In such a configuration, the valve body space 24 communicates with the secondary pressure chamber 32 through the communication hole 33 , and the working gas guided to the valve body space 24 is guided to the secondary pressure chamber 32 through the communication hole 33 . be killed.

The proximal end of the valve body 3 forms a pressure receiving surface 3e that receives the pressure (that is, the secondary pressure) of the fluid guided to the secondary pressure chamber 32, and the valve body 3 is closed by the fluid of the secondary pressure. Pushed towards position. In this way, the valve body 3 receives the secondary pressure fluid guided to the secondary pressure chamber 32 by the pressure receiving surface 3e, and the valve body 3 is arranged such that the biasing force of the spring member 6 and the secondary pressure oppose each other. It works.

In such a pressure reducing valve 1 , the spring housing space 30 is isolated from the valve body space 24 by the valve body seal 27 , and is isolated from the secondary pressure chamber 32 by the valve body seal 29 . Therefore, since the gas (that is, air) in the spring housing space 30 expands and contracts due to the movement of the valve body 3, the cover 12 is formed with an air communication hole 35 to prevent this. The air communication hole 35 opens the spring housing space 30 to the atmosphere so that air in the spring housing space 30 can be released to the atmosphere and air can be drawn into the spring housing space 30 from the atmosphere. A cap member 36 is fitted and fixed to the air communication hole 35 . The cap member 36 prevents the passage of liquid such as rain while permitting the passage of gas such as air. This can prevent liquid such as rain from entering the spring housing space 30 .

Further, the casing 2 is provided with a gas seal 37 and a waterproof seal 38 . The gas seal 37 is for suppressing the fluid from flowing out to the cover 12, the atmosphere, or the like. The gas seal 37 is composed of, for example, an O-ring made of synthetic rubber or the like, and is attached to the tip portion 13 a of the holder 13 . Specifically, the gas seal 37 is mounted on the distal end portion 13a of the holder 13 in contact with the lower surface of the flange 13b. The gas seal 37 can isolate the valve body space 24 from the spring housing space 30 and the atmosphere, thereby suppressing the fluid in the valve body space 24 from flowing out to the spring housing space 30 and the atmosphere. The waterproof seal 38 is for preventing liquid such as rain from entering the pressure reducing valve 1, and is composed of an O-ring made of synthetic rubber, for example. A seal housing space 39 is formed in the casing 2 to accommodate a waterproof seal 38 .

Next, the operation of the pressure reducing valve 1 of this embodiment will be described. The operation of reducing the pressure of the fluid guided from the external pipe 75 to the pipe connector 16 will be described below with reference to FIG. Since the valve element 3 is biased toward the opening direction by the spring member 6, the pressure reducing valve 1 is normally open, and the fluid (high pressure primary pressure fluid) guided to the piping connection portion 16 ) is led through the orifice 22 into the valve body space 24 . The fluid is decompressed from the primary pressure to a low secondary pressure when passing through the orifice 22, is led to the valve body space 24, and is supplied to downstream equipment through the secondary side passage 41 and the secondary port 42. It's like

The decompressed low-pressure (secondary pressure) fluid is led not only to the secondary side passage 41 but also to the secondary pressure chamber 32 via the communication hole 33 of the valve body 3 . As a result, the secondary pressure fluid acts on the pressure receiving surface 3e of the valve body 3, and the valve body 3 is pushed toward the closed position by the secondary pressure fluid. As a result, the valve body 3 moves in the direction to close the orifice 22, and the acting force of the secondary pressure received by the pressure receiving surface 3e, the biasing force of the spring member 6, and other forces acting on the valve body 3 are balanced. move up to For example, when the secondary pressure decreases, the acting force acting on the pressure receiving surface 3e decreases, and the biasing force of the spring member 6 exceeds the acting force acting on the pressure receiving surface 3e. Then, the valve body 3 moves toward the open position to open the orifice 22 so as to maintain a balance between the acting force acting on the pressure receiving surface 3 e and the biasing force of the spring member 6 . As a result, the secondary pressure increases and is maintained at the set pressure.

As described above, according to the pressure reducing valve 1 of the present embodiment, the casing 2 is not required to have a high strength because the casing 2 does not have a portion on which the high-pressure fluid, which is the primary pressure, acts. Therefore, since there is no need to increase the thickness of the casing 2, the overall size of the pressure reducing valve 1 does not increase. Further, in the pressure reducing valve 1, there is no need to provide a seal member (high pressure seal member) for suppressing leakage of primary pressure fluid. This eliminates the risk of fluid leakage when using high pressure seals. Furthermore, the number of parts can be reduced as compared with the aspect in which the filter of the second embodiment described later is provided.

(Second embodiment)
Next, a pressure reducing valve 1a according to a second embodiment of the present invention will be described with reference to the drawings. In addition, in 2nd Embodiment, the same code|symbol is provided to the component same as the above-mentioned 1st Embodiment, and description is abbreviate|omitted except the case where it demonstrates especially.

As shown in FIG. 2, in the pressure reducing valve 1a according to the second embodiment, the seat piece 65a has a joint portion 60 similar to that of the first embodiment, and a substantially cylindrical seat piece 65a below the joint portion 60. and a seat body portion 62a. The seat piece 65a is provided with primary passages 15a, 15b, and 15c formed along the vertical direction about the axis L1 of the pressure reducing valve 1a. The upstream end of the primary side passage 15a is connected to a primary side passage 15b formed in the seat body portion 62a and having a diameter that increases toward the upstream side. Further, the upstream end of the primary side passage 15b is connected to a primary side passage 15c formed in the seat main body portion 62a and having a larger diameter than the primary side passage 15a. Thereby, the primary side passage 15a communicates with the primary side passage 15c through the primary side passage 15b. A filter 81 is fitted to the upper portion of the primary passage 15c to prevent iron powder or the like generated when the components are attached or detached from flowing into the downstream side.

In this embodiment, an inlet housing 90 is attached to the seat piece 65a. Specifically, the inlet housing 90 includes an inlet main body 95 formed with a connection passage 92 whose downstream end communicates with the primary side passage 15c and whose upstream end communicates with the pipe passage 71 of the external pipe 75; It includes a cylindrical portion 91 provided on the upper portion of the main body portion 95 and a cylindrical portion 94 provided on the lower portion of the inlet main body portion 95 and defining an inner bottom portion 94a.

An opening at the upstream end of the connection passage 92 constitutes a pipe connection portion (primary port) 93 to which the external pipe 75 is connected. The downstream end of the piping passage 71 communicates with the piping connecting portion 93 . The seat body portion 62a is inserted into and screwed into the tubular portion 91 of the inlet housing 90, and the tubular portion 94 of the inlet housing 90 is inserted into and screwed into the tubular portion 72 of the external pipe 75. As shown in FIG. In this way, in a state in which the cylindrical portion 94 of the inlet housing 90 is inserted into and screwed into the cylindrical portion 72 of the external pipe 75, the downstream end (tip) of the pipe portion 70 is pressed against the inner bottom portion 94a of the inlet body portion 95. A metal seal is achieved by this, and the piping passage 71 and the connection passage 92 are communicated with each other in a state in which the metal seal is formed.

A second seal member 69 is provided between the seat piece 65a and the inlet housing 90 to suppress leakage of primary pressure fluid. Specifically, a recessed annular seal groove 80 is formed on the inner side of the outer peripheral surface (that is, the lower surface) of the seat main body portion 62a perpendicular to the axis L1. A second seal member 69 such as an O-ring is fitted in the seal groove 80 . The second seal member 69 seals between the seat body portion 62 a and the inlet body portion 95 . This suppresses the leakage of the primary pressure fluid to the outside.

As described above, according to the pressure reducing valve 1a of the second embodiment, as in the case of the first embodiment, the casing 2 has no portion on which the fluid of the primary pressure acts. is not required. Therefore, since it is not necessary to increase the thickness of the casing 2, the size of the pressure reducing valve 1a as a whole does not increase due to the increase in the thickness of the casing 2. In addition, although the number of parts is increased and the second seal member 69 is required between the seat piece 65a and the inlet housing 90, the filter 81 can be built in as compared with the first embodiment without the filter 81. can. As a result, it is possible to deal with an external pipe 75 that is not provided with a filter.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. For example:

In the first and second embodiments, an O-ring may be provided around the downstream end of the pipe passage 71 at the tip of the pipe portion 70 of the external pipe 75 . Thereby, the reliability of sealing between the piping passage 71 and the connection passage 92 can be further improved.

Further, in the first and second embodiments, the joint portion 60 of the sheet piece 65 is inserted into the hole portion 50 formed in the casing 2 and joined. You may comprise so that it may be inserted in the hole part 50 and screwed. In this case, a first seal member can be provided between the lower surface of the casing 2 and the upper surface of the seat body portion 62 .

Furthermore, although the holder 13 is provided with the flange 13b in the first and second embodiments, the flange 13b may be omitted. In this case, the outer peripheral surface of the holder 13 is fitted to the inner peripheral surface of the cover 12, and a spring member 6 can be provided between the upper end of the holder 13 and the portion of the valve body 3 arranged opposite to the upper end. . Thereby, the diameter of the cover 12 can be reduced.

1, 1a pressure reducing valve 2 casing 3 valve body 15, 15a, 15b, 15c primary side passage 16 pipe connection portion 20 valve seat portion 24 valve body space 41 secondary side passage 62, 62a seat body portion 63 first sealing member ( secondary pressure seal member)
65, 65a Seat piece 67a Inner bottom 69 Second sealing member (primary pressure sealing member)
70 piping section 71 piping passage 72 cylinder section 73 bottom section 74 holding section 75 external piping 81 filter 90 inlet housing 92 connecting passageway 93 connecting section for piping 94a inner bottom section 95 inlet body section

Claims (6)

A pressure reducing valve for reducing the pressure of a primary pressure fluid flowing from an external pipe to a secondary pressure,
a seat piece having a primary passage communicating with the external pipe, and a valve seat portion formed downstream of the primary passage;
a valve body that moves between a closed position seated on the valve seat portion and an open position spaced apart from the valve seat portion;
a casing having a secondary passage and a valve body space formed between the primary passage and the secondary passage and in which the valve body is arranged;
a secondary pressure seal member provided between the casing and the seat piece , and provided downstream of the valve seat portion in a direction in which the fluid flows . The seat piece has a piping connection portion formed upstream of the primary passage,
2. The pressure reducing valve according to claim 1, wherein leakage of primary pressure fluid is prevented by connecting an external pipe to said pipe connecting portion of said seat piece. The seat piece includes a concave seat main body portion formed with the pipe connection portion connected to the external pipe at the inner bottom,
The external pipe includes a pipe portion provided with a pipe passage that communicates with the primary passage, and a cylindrical portion into which the seat body portion is inserted and screwed,
A downstream end of the pipe portion is configured to be pressed against the pipe connection portion of the seat body portion in a state where the seat body portion is inserted into and screwed to the cylindrical portion of the external pipe. 3. A pressure reducing valve according to claim 2. a filter provided in the primary passage of the seat piece;
an inlet housing having a connection passage whose upstream end constitutes a connecting portion with the external pipe and whose downstream end communicates with the primary side passage of the seat piece;
2. The pressure reducing valve according to claim 1, further comprising a primary pressure sealing member provided between said seat piece and said inlet housing. The inlet housing has a piping connection portion formed upstream of the connection passage,
5. The pressure reducing valve according to claim 4, wherein leakage of primary pressure fluid is prevented by connecting an external pipe to the pipe connecting portion of the inlet housing. The inlet housing has a recessed inlet main body portion formed with the pipe connection portion connected to the external pipe on the inner bottom,
The external pipe includes a pipe portion provided with a pipe passage that communicates with the connection passage, and a cylindrical portion into which the inlet body portion is inserted and screwed,
A downstream end of the pipe portion is configured to be pressed against the pipe connection portion of the inlet main body portion in a state where the inlet main body portion is inserted into and screwed into the tubular portion of the external pipe. A pressure reducing valve according to claim 5.

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