Pressure reducing valve

Abstract

This pressure reducing valve includes: a casing including a passage; a valve body movably housed in the casing and adjusting an opening degree of the passage; a first biasing member for biasing the valve body in a closing direction; a stem housed in the casing so as to be movable and abutting on the valve body; and a second biasing member for biasing the valve body in an opening direction so as to resist secondary pressure via the stem. The second biasing member is a plate-shaped spring and extends laterally from the stem.

Description

Technical Field

[0001] The present disclosure relates to a pressure reducing valve that reduces the pressure of a gas and outputs it.

Background Art

[0002] As a pressure reducing valve for gases such as compressed natural gas and hydrogen gas, for example, a pressure reducing valve as disclosed in Patent Document 1 is known. In the pressure reducing valve of Patent Document 1, the biasing force of a compression coil spring and the secondary pressure act on a piston so as to oppose each other. The piston adjusts the opening degree of a valve passage by pushing a valve body with a force corresponding to the secondary pressure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pressure reducing valve of Patent Document 1, since a piston is biased by a compression coil spring, the size of the pressure reducing valve, particularly the length in the axial direction, becomes large.

[0005] Therefore, an object of the present disclosure is to provide a pressure reducing valve that can be miniaturized.

Means for Solving the Problems

[0006] The pressure reducing valve of the present disclosure includes a casing including a passage, a valve body movably accommodated in the casing for adjusting the opening degree of the passage, a first biasing member for biasing the valve body in the closing direction, a stem movably accommodated in the casing and abutting against the valve body, and a second biasing member for biasing the valve body in the opening direction against the secondary pressure via the stem. The second biasing member is a plate-shaped spring that extends laterally from the stem.

[0007] According to the pressure reducing valve of this disclosure, the second biasing member is a plate-shaped spring extending laterally from the stem. Therefore, the axial dimensions of the pressure reducing valve can be reduced. [Effects of the Invention]

[0008] According to this disclosure, miniaturization is possible.

[0009] The above-mentioned purposes, other purposes, features, and advantages of this disclosure will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing a pressure reducing valve according to an embodiment of the present disclosure. [Figure 2] Figure 1 is a cross-sectional view showing the state in which the valve body is seated on the valve seat in a pressure reducing valve. [Figure 3] This is an enlarged cross-sectional view showing the stem and leaf spring area of ​​the pressure reducing valve in Figure 1. [Figure 4] Figure 3 is an enlarged cross-sectional view showing a magnified view of region X in the pressure reducing valve. [Figure 5] Figure 1 is a cross-sectional view showing the gas flow in a pressure reducing valve. [Modes for carrying out the invention]

[0011] Hereinafter, the pressure reducing valve 1 of the embodiment relating to this disclosure will be described with reference to the aforementioned drawings. Note that the concept of direction used in the following description is for convenience of explanation and does not limit the orientation of the configuration of this disclosure to that direction. Furthermore, the pressure reducing valve 1 described below is merely one embodiment of this disclosure. Therefore, this disclosure is not limited to the following embodiment, and additions, deletions, and modifications are permitted without departing from the spirit of this disclosure.

[0012] The pressure reducing valve 1 shown in Figure 1 is used to reduce the pressure of gases such as compressed natural gas and hydrogen gas to the operating pressure or atmospheric pressure. The pressure reducing valve 1 comprises a casing 10, a valve body 11, a coil spring 12, a stem 13, and a leaf spring 14. In the pressure reducing valve 1 of this embodiment, the casing 10, valve body 11, coil spring 12, stem 13, and leaf spring 14 are arranged along a predetermined axis L1.

[0013] <Casing> The casing 10 has a passage 15. The casing 10 also has a housing space 16. Furthermore, the casing 10 has a primary side passage 17, a valve body chamber 18, a guide section 19, and a secondary side passage 20. The primary side passage 17 has a primary port 17a, through which gas is input. The primary side passage 17 is connected to the valve body chamber 18. The valve body chamber 18 is connected to the guide section 19 via passage 15. The guide section 19 is connected to the secondary side passage 20 via a secondary chamber 36 of the housing space 16, which will be described in detail later. The secondary side passage 20 has a secondary port 20a, through which gas flows. More specifically, the casing 10 includes a joint section 21, a valve body housing 22, a seat 23, a casing body 24, and a cover 25. The casing 10 also includes a filter 26.

[0014] The joint portion 21 has a primary side passage 17, a housing mounting portion 28, and a seat mounting portion 29. The primary side passage 17, the housing mounting portion 28, and the seat mounting portion 29 are formed along the axis L1 in the joint portion 21. That is, the joint portion 21 is formed in a cylindrical shape, and the primary side passage 17, the housing mounting portion 28, and the seat mounting portion 29 form an internal bore of the joint portion 21. The primary side passage 17, the housing mounting portion 28, and the seat mounting portion 29 are formed in the joint portion 21 in that order from one axial side. A primary port 17a is formed at one axial end of the joint portion 21, and the seat mounting portion 29 opens at the other axial end of the joint portion 21. The axial direction is the direction in which the axis L1 extends. The housing mounting portion 28 is formed with a larger diameter than the primary side passage 17. The seat mounting portion 29 is formed with a larger diameter than the housing mounting portion 28. Furthermore, a pipe (not shown) is connected to one axial portion of the joint 21. A nut is formed in the middle portion of the joint 21. A male thread is formed on the other axial portion of the joint 21.

[0015] The valve housing 22 has a valve body 11, which will be described in detail later, inserted through it so that it can slide in the axial direction. The valve housing 22 is housed in the housing mounting portion 28 with the valve body 11 inserted through it. More specifically, the valve housing 22 is formed in a cylindrical shape. A filter 26 is attached to one axial end of the valve housing 22. The filter 26 is attached to the valve housing 22 so as to cover the opening on one axial side of the valve housing 22. The filter 26 captures contaminants and the like contained in the gas flowing from the primary side passage 17. The inner bore of the valve housing 22 is formed such that the middle portion is smaller in diameter than the remaining portion. In the inner bore of the valve housing 22, the portion on the axial side of the middle portion forms the valve chamber 18. The valve body 11 is slidably inserted through the valve chamber 18.

[0016] The seat 23 is attached to the seat mounting portion 29 of the joint portion 21. More specifically, the seat 23 is fitted into the seat mounting portion 29. The seat 23 is formed, for example, in an annular shape and has a through hole 23a. The through hole 23a is formed along the axis L1. The valve body 11 is seated on the seat 23. This closes the through hole 23a. The seat 23 is made of, for example, synthetic resin. However, the seat 23 may be made of a metal such as stainless steel.

[0017] The casing body 24 has a joint mounting portion 30, a communication hole 31, a guide portion 19, a housing space 16, a cover mounting portion 33, and a secondary side passage 20. The joint mounting portion 30, the communication hole 31, the guide portion 19, the housing space 16, and the cover mounting portion 33 are formed along the axis L1. More specifically, the joint mounting portion 30, the communication hole 31, the guide portion 19, the housing space 16, and the cover mounting portion 33 are formed in the casing body 24 in that order from one axial side. The joint mounting portion 30 and the cover mounting portion 33 are open at one axial end and the other end of the casing body 24, respectively.

[0018] The other axial portion of the joint 21 is inserted into and attached to the joint mounting portion 30. More specifically, the joint mounting portion 30 has an internal thread. The other axial portion of the joint 21 is screwed into the joint mounting portion 30 in a manner that achieves a seal. More specifically, the seat 23 is attached to the seat mounting portion 29 of the joint 21 with the seat 23 slightly protruding, and the seat 23 is screwed into the joint mounting portion 30 so as to press against the bottom of the joint mounting portion 30. Note that the joint 21 does not necessarily have to be screwed into the joint mounting portion 30, and may be fixed to the joint mounting portion 30 by other means such as fastening and fitting.

[0019] The communication hole 31 is connected to the joint attachment portion 30 and is formed with a smaller diameter than the joint attachment portion 30. More specifically, the communication hole 31 is connected to the through hole 23a of the sheet 23 and constitutes the passage 15 together with the through hole 23a. Note that the communication hole 31 is formed with the same hole diameter as the through hole 23a in the present embodiment.

[0020] The guide portion 19 is connected to the communication hole 31 and is formed with a larger diameter than the communication hole 31. The stem 13, which will be described in detail later, is slidably inserted into the guide portion 19, and the stem 13 is slidably guided in the axial direction. The accommodation space 16 is connected to the guide portion 19 and is formed with a larger diameter than the guide portion 19. In the present embodiment, the accommodation space 16 is formed with a larger diameter than the joint attachment portion 30, the communication hole 31, and the guide portion 19. The cover attachment portion 33 is formed on the other axial side of the accommodation space 16 and is formed with a larger diameter than the accommodation space 16. Thereby, a stepped portion 33a is formed over the entire circumference around the opening of the accommodation space 16.

[0021] The secondary side passage 20 is formed at a radially outer position away from the axis L1. In the present embodiment, the secondary side passage 20 is formed at a radially outer position of the guide portion 19. The secondary side passage 20 is connected to the accommodation space 16. Further, as described above, the secondary side passage 20 has the secondary port 20a, and the secondary port 20a opens, for example, on the side surface of the casing body 24.

[0022] The cover 25 is attached to the cover mounting portion 33. More specifically, the cover 25 has a convex portion 25a that protrudes in one axial direction. The convex portion 25a is fitted into the cover mounting portion 33 in a state that achieves a seal. This closes the housing space 16. The cover 25 is fastened to the casing body 24 by fastening members, for example (not shown). The cover 25 may also be attached to the casing body 24 by a method other than fastening by fastening members, for example, by a screw-in method in which the cover 25 is screwed into the casing body 24. At one axial end face of the cover 25, i.e., the end face of the convex portion 25a, the outer peripheral edge protrudes in one axial direction along the entire circumference. The cover 25 also has an atmospheric vent hole 25b formed along the axis L1.

[0023] <valve body> The valve body 11 is movably housed in the casing 10. The valve body 11 also changes position according to the secondary pressure to adjust the opening of the passage 15. In this embodiment, the valve body 11 is a bottomed cylindrical member. That is, the inner bore of the valve body 11 is open at one end in the axial direction. The tip portion on the other axial side of the valve body 11 is tapered (frustoconical in this embodiment). Furthermore, a plurality of through passages 11a are formed in the tip portion of the valve body 11. The through passages 11a extend from the inner bore of the valve body 11 to the side surface of the tip portion (tapered surface in this embodiment) and are open. The axial end portion of the valve body 11 is also recessed radially inward along its entire circumference. The valve body 11 is made of a metal such as stainless steel. However, if the seat 23 is made of a metal such as stainless steel, the valve body 11 is molded from synthetic resin. If the seat 23 is made of synthetic resin, the valve body 11 may be molded from metal. Furthermore, both the valve body 11 and the seat 23 may be molded from synthetic resin or metal.

[0024] As described above, the valve body 11 is slidably inserted into the valve body housing 22 in the axial direction. The inner bore of the valve body 11 is connected to the primary side passage 17 via the other axial side portion of the inner bore of the valve body housing 22 and the filter 26. The tip portion of the valve body 11 is formed in a frustoconical shape as described above, forming an annular passage 22a between it and the valve body housing 22. The inner bore of the valve body 11 is connected to the annular passage 22a via the through passage 11a. Furthermore, as shown in Figure 2, the valve body 11 seats on the seat 23 by moving in the other axial direction, which is an example of the closing direction (i.e., the direction that closes the passage 15). This closes the passage 15. On the other hand, the valve body 11 moves away from the seat 23 by moving in the one axial direction, which is an example of the opening direction (i.e., the direction that opens the passage 15). This opens the passage 15. This connects the annular passage 22a to the passage 15. The valve body 11 then adjusts the opening of the passage 15 by moving closer to or further away from the seat 23 (i.e., moving axially).

[0025] <Coil spring> An example of a first biasing member is a coil spring 12, which biases the valve body 11 in the other axial direction. The coil spring 12 is, for example, a compression coil spring. The coil spring 12 is externally mounted on the valve body 11. More specifically, the coil spring 12 is externally mounted on a recessed portion at one axial end of the valve body 11. This reduces the axial dimension of the pressure reducing valve 1. One end of the coil spring 12 abuts against the valve body 11, and the other end abuts against the middle portion of the valve body housing 22. As a result, the valve body 11 is biased in the other axial direction by the coil spring 12. Note that the coil spring 12 does not necessarily need to be externally mounted on the valve body 11; it may abut against one axial end of the valve body 11.

[0026] The stem 13 is movably housed in the casing 10 as shown in Figure 3. More specifically, the stem 13 is axially slidably guided within the casing 10. In this embodiment, the stem 13 is slidably inserted into the guide portion 19 of the casing body 24. The stem 13 also abuts against the valve body 11. More specifically, the stem 13 has a contact portion 13a on one axial side (i.e., the tip side). The contact portion 13a is elongated and protrudes from the guide portion 19 through the passage 15 into the valve chamber 18. The contact portion 13a is smaller in diameter than the passage 15. Therefore, gas flows around the contact portion 13a towards the guide portion 19. The contact portion 13a also abuts against the valve body 11 in the valve chamber 18. In this embodiment, the tip of the contact portion 13a abuts against the tip of the valve body 11.

[0027] On the other hand, the stem 13 has a sliding portion 13b on the other axial side (i.e., the base end side). Multiple connecting passages 13c are formed on the outer circumferential surface of the sliding portion 13b. The connecting passages 13c are arranged at intervals in the circumferential direction on the outer circumferential surface of the sliding portion 13b. The connecting passages 13c may be formed on the inner circumferential surface of the guide portion 19 instead of the outer circumferential surface of the sliding portion 13b. Furthermore, the connecting passages 13c extend from one end to the other end of the sliding portion 13b.

[0028] The sliding portion 13b is fitted into the guide portion 19 so as to be slidable in the axial direction, and is axially guided by the guide portion 19. The sliding portion 13b is also positioned away from the bottom surface of the guide portion 19 in the other axial direction. Therefore, an annular passage 19a is formed between the sliding portion 13b and the bottom surface of the guide portion 19, around the contact portion 13a. The annular passage 19a is connected to the passage 15 and also to the accommodation space 16 (more specifically, the secondary chamber 36 which will be described in detail later) via the aforementioned multiple connecting passages 13c.

[0029] An example of a second biasing member, a leaf spring 14, is attached to the stem 13. In this embodiment, the leaf spring 14 abuts against the base end surface of the stem 13, as will be described later. However, the leaf spring 14 may be fixed to the stem 13 by welding or the like. The leaf spring 14 generates a restoring force corresponding to the displacement. The leaf spring 14 then moves the stem 13 with the restoring force it generates. The leaf spring 14 moves the valve body 11 in one axial direction by biasing the stem 13 in one axial direction. The leaf spring 14 is, for example, a plate-shaped metal member (in this embodiment, a member made of SUS such as SUS304CSP and an alloy). The leaf spring 14 is a plate member that has a solid circular shape when viewed in the axial direction. More specifically, the leaf spring 14 is formed convex in one axial direction. That is, the leaf spring 14 is formed with a convex cross-section in which the central portion 14a protrudes in one axial direction.

[0030] To explain in more detail, the central portion 14a of the leaf spring 14 is larger in diameter than the outer diameter of the valve body 11 and is flat. The outer edge portion 14b of the leaf spring 14 is also flat. Furthermore, the leaf spring 14 has a tapered portion 14c connecting the outer edge portion 14b and the central portion 14a, formed as follows. That is, the tapered portion 14c is tapered as shown in Figure 4. In this embodiment, the tapered portion 14c is tapered at multiple angles. To explain in detail, the outer edge portion 14d and the central portion 14e of the tapered portion 14c have different tapered angles α and β. That is, the tapered angle β of the central portion 14e is acuter than the tapered angle α of the outer edge portion 14d.

[0031] The leaf spring 14 biases the valve body 11 in one axial direction to resist secondary pressure via the stem 13. By biasing, the leaf spring 14 moves the valve body 11 in one axial direction. The leaf spring 14 is provided in the casing 10. More specifically, the leaf spring 14 is housed in a housing space 16. The leaf spring 14 extends laterally beyond the stem 13 when viewed in the axial direction. The leaf spring 14 also divides the housing space 16 into a secondary chamber 36 and an open space 35.

[0032] The secondary chamber 36 is a space into which secondary pressure is introduced and is formed to face the leaf spring 14. In this embodiment, the secondary chamber 36 is a space in the containment space 16 that is axially on one side of the leaf spring 14. As described above, the secondary chamber 36 is connected to the passage 15 via a plurality of connecting passages 13c. The secondary pressure, which has been reduced by the valve body 11 adjusting the opening of the passage 15, is introduced into the secondary chamber 36 through the passage 15 and the plurality of connecting passages 13c. The leaf spring 14 faces the secondary chamber 36. Therefore, the leaf spring 14 receives secondary pressure in a direction that is opposed to the biasing force of the leaf spring 14. Also, as described above, the secondary chamber 36 is connected to the secondary side passage 20, and gas flows from the secondary chamber 36 to the secondary side passage 20.

[0033] The open space 35 is located on the axial opposite side of the secondary chamber 36, with the leaf spring 14 in between. The open space 35 is connected to the atmosphere through the atmospheric vent 25b of the cover 25. The open space 35 draws in and expels air through the atmospheric vent 25b. This allows for elastic deformation of the leaf spring 14 without increasing the internal pressure of the open space 35.

[0034] Furthermore, the leaf spring 14 seals the space between the open space 35 and the secondary chamber 36. More specifically, the leaf spring 14 is provided in the casing 10 by being sandwiched between the casing body 24 and the cover 25. In this embodiment, the outer edge portion 14b of the leaf spring 14 is sandwiched and sealed between the stepped portion 33a of the casing body 24 and the outer peripheral edge portion of the convex portion 25a of the cover 25 over its entire circumference. As a result, the leaf spring 14 is provided in the casing 10 so as to divide the housing space 16 into the open space 35 and the secondary chamber 36 and to seal the space between the open space 35 and the secondary chamber 36.

[0035] Furthermore, as described above, the leaf spring 14 is formed in a convex shape in one axial direction, and the central portion 14a of the leaf spring 14 abuts against the base end surface of the stem 13. The stem 13 abuts against the valve body 11 as described above. The valve body 11 is biased in the other axial direction by the coil spring 12. Therefore, the stem 13 is pushed in the other axial direction by the valve body 11, and the leaf spring 14 is further pushed in the other axial direction by the stem 13. That is, the leaf spring 14 receives the biasing force of the coil spring 12 in the other axial direction via the valve body 11 and the stem 13. Then, the leaf spring 14 biases the stem 13 in one axial direction against the biasing force of the coil spring 12, and biases the valve body 11 in one axial direction via the stem 13.

[0036] <Operation of the pressure reducing valve> In the pressure reducing valve 1, gas at primary pressure flows in from the primary port 17a, as shown by arrow A in Figure 5. The incoming gas is guided to the filter 26 through the primary side passage 17. In the filter 26, contaminants contained in the gas are captured. The gas is then guided to the valve chamber 18 of the valve body housing 22, and further guided to the annular passage 22a through the inner bore of the valve body 11 and multiple through passages 11a. Furthermore, the gas is guided from the annular passage 22a through passage 15 to the annular passage 19a. The opening of passage 15 is adjusted by the valve body 11. As a result, the secondary pressure is adjusted to a pressure corresponding to the opening of passage 15. The gas is then guided from the annular passage 19a through multiple connecting passages 13c to the secondary chamber 36, and further flows out from the secondary chamber 36 through the secondary side passage 20 to the secondary port 20a.

[0037] In the pressure reducing valve 1 through which gas flows, the valve body 11 changes its position in accordance with the secondary pressure to adjust the opening of the passage 15. Specifically, the valve body 11 is subjected to biasing forces from the coil spring 12 and the leaf spring 14 in opposing directions, and the leaf spring 14 is further subjected to secondary pressure in the other axial direction. Therefore, the valve body 11 moves to a position where the biasing force of the coil spring 12, the biasing force of the leaf spring 14, and the secondary pressure are balanced. As a result, the valve body 11 moves to a position corresponding to the secondary pressure, adjusting the opening of the passage 15 and maintaining the secondary pressure at a predetermined pressure.

[0038] In this case, the leaf spring 14 undergoes elastic deformation as follows. Specifically, in the leaf spring 14, the taper angle β of the central portion 14e is acuter than the taper angle α of the outer edge portion 14d. Therefore, the leaf spring 14 can move its central portion 14a parallel to the axial direction while its outer edge is clamped. More specifically, in the leaf spring 14, the tapered portion 14c undergoes elastic deformation while changing the relative angle between the outer edge portion 14d and the central portion 14e. The tapered portion 14c then moves the central portion 14a parallel to the tapered portion 14c. Therefore, the leaf spring 14 can bring the base end surface of the stem 13 and the central portion 14a into contact with each other in a flat state. This prevents the stem 13 from making uneven contact with the leaf spring 14. Furthermore, the tapered portion 14c does not necessarily need to have different taper angles for the outer edge portion 14d and the central portion 14e; it may be formed with a single taper angle.

[0039] Furthermore, in the cover 25, the outer peripheral edge of the convex portion 25a protrudes in one axial direction along the entire circumference. That is, the radially inward portion of the convex portion 25a is recessed. Therefore, when the leaf spring 14 bends in the other axial direction, the outer edge portion 14b is prevented from contacting the convex portion 25a. This ensures that there is space for the leaf spring 14 to bend. That is, the inner portion of the outer edge portion 14b can bend toward the convex portion 25a. Therefore, the height of the leaf spring 14 in the pressure reducing valve 1 can be further reduced.

[0040] In the pressure reducing valve 1 of this embodiment, the leaf spring 14 is a plate-shaped spring that extends laterally from the stem 13. Therefore, the axial dimensions of the pressure reducing valve 1 can be reduced.

[0041] Furthermore, in the pressure reducing valve 1 of this embodiment, the secondary chamber 36 is formed to face the leaf spring 14. Therefore, the leaf spring 14 receives secondary pressure in the secondary chamber 36 and moves the valve body 11 to a position corresponding to the secondary pressure via the stem 13. As a result, the opening degree of the passage 15 is adjusted according to the secondary pressure. In conventional pressure reducing valves, a compression coil spring biases the stem via a pressure receiving member, but in the pressure reducing valve 1, the stem 13 can be directly biased by the leaf spring 14. Therefore, the pressure receiving member that receives secondary pressure in the pressure reducing valve 1 can be omitted, and the number of parts in the pressure reducing valve 1 can be reduced.

[0042] Furthermore, in the pressure reducing valve 1 of this embodiment, the leaf spring 14 divides the housing space 16 into an open space 35 and a secondary chamber 36, and seals the space between the secondary chamber 36 and the open space 35. Therefore, since the leaf spring 14 also has a sealing function, the number of parts can be reduced. As a result, the pressure reducing valve 1 can be made smaller.

[0043] Furthermore, in the pressure reducing valve 1 of this embodiment, the leaf spring 14 is in contact with the base end surface of the stem 13. Therefore, the leaf spring 14 can be displaced relative to the stem 13. This prevents the stem 13 from sliding eccentrically within the casing 10. Consequently, the stem 13 can move smoothly.

[0044] Furthermore, in the pressure reducing valve 1 of this embodiment, the leaf spring 14 is formed in a convex disc shape in the opening direction. Therefore, the stem 13 can be smoothly biased in the opening direction while keeping the height of the pressure reducing valve 1 low.

[0045] Furthermore, in the pressure reducing valve 1 of this embodiment, the leaf spring 14 includes an outer edge portion 14b and a central portion 14a. The outer edge portion 14b is flat and attached to the casing 10. The central portion 14a is flat and in contact with the stem 13. Therefore, the leaf spring 14 can be easily attached to the casing 10 and the stem 13.

[0046] Furthermore, in the pressure reducing valve 1 of this embodiment, the leaf spring 14 has a tapered portion 14c. Therefore, when the leaf spring 14 bends, the tapered portion 14c elastically deforms while changing the relative angle with the outer edge portion 14b and the central portion 14a, allowing the central portion 14a to move parallel to the leaf spring. This allows the stem 13 to be brought into straight contact with the leaf spring.

[0047] Furthermore, in the pressure reducing valve 1 of this embodiment, the communication passage 13c is connected to the secondary passage 20 via the secondary chamber 36. Therefore, the number of passages formed in the casing 10 can be reduced. This prevents the pressure reducing valve 1 from becoming too large.

[0048] [Other embodiments] In this embodiment, the leaf spring 14 is in contact with the valve body 11, but it may also be fixed to the valve body 11. Furthermore, the leaf spring 14 is not limited to the shape described above, and may be any plate shape (for example, rectangular when viewed in the axial direction) that extends laterally from the valve body 11. In addition, the leaf spring 14 does not necessarily need to have a pressure-receiving function or a sealing function, which may be achieved by the valve body 11 and other components. That is, a pressure-receiving part may be formed in the valve body 11 or stem 13, or a seal may be achieved using an O-ring or diaphragm.

[0049] Furthermore, the secondary chamber 36 and the secondary side passage 20 do not necessarily need to be connected; the secondary side passage 20 may be directly connected to the annular passage 19a. Also, the secondary chamber 36 may be connected to the passage 15 via the secondary side passage 20, or the secondary side passage 20 connected to the annular passage 19a may be connected via another passage or external piping. In addition, a connecting passage 13c does not necessarily need to be formed in the stem 13 to guide the secondary pressure to the secondary chamber 36. For example, multiple connecting passages may be formed in the guide section 19. Also, the connecting passage may be formed inside the stem 13, or it may be formed in the casing body 24.

[0050] The pressure reducing valve in the first phase comprises a casing including a passage, a valve body movably housed in the casing and adjusting the opening of the passage, a first biasing member that biases the valve body in the closing direction, a stem movably housed in the casing and in contact with the valve body, and a second biasing member via the stem that biases the valve body in the opening direction to resist secondary pressure, wherein the second biasing member is a plate-shaped spring extending laterally from the stem.

[0051] According to the above description, the second biasing member is a plate-shaped spring extending laterally from the stem. Therefore, the axial dimension of the pressure reducing valve can be reduced.

[0052] In the second phase, the pressure reducing valve, in the first phase, has a casing that includes a secondary chamber through which a secondary pressure is introduced, and the secondary chamber is formed to face the second biasing member.

[0053] According to the above description, the secondary chamber is formed to face the second biasing member. Therefore, the second biasing member receives secondary pressure from the secondary chamber and moves the valve body to a position corresponding to the secondary pressure via the stem. This adjusts the opening of the passage according to the secondary pressure. Consequently, the pressure receiving member that receives the secondary pressure can be omitted, and the number of parts in the pressure reducing valve can be reduced.

[0054] The pressure reducing valve in the third phase is the same as the pressure reducing valve in the second phase, wherein the casing includes a housing space for housing the second biasing member, and the second biasing member divides the housing space into an open space open to the atmosphere and the secondary chamber, and seals the space between the secondary chamber and the open space.

[0055] According to the above procedure, the second biasing member divides the housing space into an open space and a secondary chamber, and seals the space between the secondary chamber and the open space. Therefore, since the second biasing member also has a sealing function, the number of parts can be reduced. This makes it possible to miniaturize the pressure reducing valve.

[0056] In the fourth phase, the pressure reducing valve is such that, in any of the first to third phases, the stem is arranged to be slidably guided within the casing, and the second biasing member abuts against the end face of the stem.

[0057] In the above scenario, the second biasing member is in contact with the end face of the stem. Therefore, the second biasing member can be displaced relative to the stem. This prevents the stem from sliding eccentrically within the casing. Consequently, the stem can move smoothly.

[0058] In the fifth phase, the pressure reducing valve is formed in a convex disc shape in the opening direction, as in the pressure reducing valve of any of the first to fourth phases.

[0059] According to the above description, the second biasing member is formed in a disc shape that is convex in the opening direction. Therefore, the stem can be smoothly biased in the opening direction while keeping the height of the pressure reducing valve low.

[0060] The pressure reducing valve in the sixth phase is the same as the pressure reducing valve in the fifth phase, wherein the second biasing member includes an outer edge portion and a central portion, the outer edge portion of the second biasing member being flat and attached to the casing, and the central portion of the second biasing member being flat and in contact with the stem.

[0061] According to the above description, the second biasing member includes an outer edge portion and an intermediate portion. The outer edge portion is flat and attached to the casing. The intermediate portion is flat and in contact with the stem. Therefore, the second biasing member can be easily attached to the casing and the stem.

[0062] In the seventh phase, the pressure reducing valve, in the sixth phase, includes a tapered portion connecting the outer edge portion and the central portion of the second biasing member.

[0063] According to the above description, the second biasing member has a tapered portion connecting the outer edge portion and the central portion. Therefore, when the leaf spring flexes, the tapered portion elastically deforms while changing the relative angle with the outer edge portion and the central portion, allowing the central portion to move parallel to the tapered portion. This allows the stem to be pushed straight.

[0064] The pressure reducing valve in the eighth phase is a pressure reducing valve in the second or third phase, wherein the casing includes a guide portion for sliding the stem and a secondary side passage connected to a secondary port, and a connecting passage connected to the secondary chamber is formed in at least one of the guide portion and the stem, and the connecting passage is connected to the secondary side passage via the secondary chamber.

[0065] According to the above description, the connecting passage is connected to the secondary passage via the secondary chamber. Therefore, the number of passages formed in the casing can be reduced. This helps to prevent the pressure reducing valve from becoming too large.

[0066] From the above description, many improvements and other embodiments of the disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the disclosure. The details of its structure and / or function can be substantially modified without departing from the spirit of the disclosure. [Explanation of symbols]

[0067] 1. Pressure Reducing Valve 10 Casing 11 Valve body 12. Coil spring (first biasing member) 13 Stem 13c Communication path 14. Leaf spring (second biasing member) 14a center part 14b Outer edge portion 14c tapered section 15 aisles 16 Containment space 19 Guide Section 20 Secondary side passage 35 Open Space 36 Secondary Chamber

Claims

1. Casing including passageway, A valve body is movably housed in the casing and adjusts the opening degree of the passage, A first biasing member that biases the valve body in the closing direction, A stem is movably housed in the casing and contacts the valve body, The valve body is biased in the opening direction via the stem, to resist secondary pressure, The second biasing member is a plate-shaped spring extending laterally from the stem, in a pressure reducing valve.

2. The casing includes a secondary chamber through which secondary pressure is introduced. The pressure reducing valve according to claim 1, wherein the secondary chamber is formed to face the second biasing member.

3. The casing includes a housing space for housing the second biasing member, The pressure reducing valve according to claim 2, wherein the second biasing member divides the housing space into an open space that is open to the atmosphere and the secondary chamber, and seals the space between the secondary chamber and the open space.

4. The stem is arranged to be slidably guided within the casing. The pressure reducing valve according to claim 1, wherein the second biasing member is in contact with the end face of the stem.

5. The pressure reducing valve according to claim 1, wherein the second biasing member is formed in the shape of a convex disc in the opening direction.

6. The second biasing member includes an outer edge portion and a central portion, The outer edge portion of the second biasing member is flat and attached to the casing. The pressure reducing valve according to claim 5, wherein the central portion of the second biasing member is flat and in contact with the stem.

7. The pressure reducing valve according to claim 6, wherein the second biasing member includes a tapered portion connecting the outer edge portion and the central portion.

8. The casing includes a guide portion that slides and guides the stem, and a secondary side passage connected to a secondary port. A connecting passage to the secondary chamber is formed in at least one of the guide portion and the stem. The pressure reducing valve according to claim 2, wherein the communication passage is connected to the secondary side passage via the secondary chamber.

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