Pressure reducing valve and valve device

Abstract

This pressure reducing valve is provided with: a casing in which a valve passage is formed; a valve body that is housed in the casing so as to be movable in the axial direction, and adjusts the degree of opening of the valve passage according to the secondary pressure; and a biasing member that is housed in the casing and biases the valve body in one direction in the axial direction against the secondary pressure. The biasing member is a plate-shaped spring extending radially outward from the valve body, and is compressed and deformed in the axial direction when the secondary pressure is at least equal to atmospheric pressure.

Description

[Technical Field]

[0001] The present disclosure relates to a pressure reducing valve that adjusts the opening degree of a valve passage, and a valve device. [Background technology]

[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, a secondary pressure acts on a valve element in a closing direction. The valve element is also provided with a leaf spring. The leaf spring biases the valve element against the secondary pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-124130 Summary of the Invention [Problem to be solved by the invention]

[0004] In the pressure reducing valve of Patent Document 1, the outer edge portion of the leaf spring is fixed by the casing. Therefore, when the valve disc reciprocates, a large load amplitude occurs near the outer edge portion. Therefore, in pressure reducing valves, it is desirable to improve the durability of the leaf spring, which is the biasing member, by taking measures against the load amplitude.

[0005] An object of the present disclosure is to provide a pressure reducing valve and a valve device that can improve the durability of a biasing member. [Means for solving the problem]

[0006] The pressure reducing valve of the first disclosure comprises a casing in which a valve passage is formed, a valve body housed in the casing so as to be movable in the axial direction and which adjusts the opening of the valve passage in accordance with a secondary pressure, and a biasing member housed in the casing and biasing the valve body in one axial direction against the secondary pressure, the biasing member being a plate-shaped spring extending radially outward from the valve body and being compressed and deformed in the axial direction at least when the secondary pressure is equal to atmospheric pressure.

[0007] According to the first disclosure, the biasing member is compressively deformed in the axial direction. That is, an initial load can be applied to the biasing member in the axial direction before the valve body is actuated. Therefore, when the valve body reciprocates, the amount of change in the load acting on the biasing member can be suppressed. That is, the load amplitude generated in the biasing member can be reduced. This improves the durability of the biasing member.

[0008] The valve device disclosed in the second disclosure comprises a casing in which a valve passage is formed, a valve body housed in the casing so as to be movable in the axial direction and which changes its position in response to an acting force to change the opening degree of the valve passage, and a biasing member housed in the casing and biasing the valve body in one axial direction to open the valve passage against the acting force, the biasing member being a plate-shaped spring extending laterally from the valve body and being compressed and deformed in the axial direction by the casing.

[0009] According to the second disclosure, the biasing member is compressively deformed in the axial direction by the casing. That is, an initial load can be applied to the biasing member in the axial direction before the valve body is actuated. Therefore, when the valve body reciprocates, the amount of change in the load acting on the biasing member can be suppressed. That is, the load amplitude acting on the biasing member can be reduced. This improves the durability of the biasing member. [Effects of the Invention]

[0010] According to the present disclosure, the durability of the biasing member can be improved. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view illustrating a pressure reducing valve according to an embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view showing a leaf spring provided in the pressure reducing valve of FIG. 1. [Figure 3] 2 is an enlarged cross-sectional view showing an area X in the pressure reducing valve of FIG. 1. FIG. [Figure 4] 2 is an enlarged cross-sectional view showing an area Y in the pressure reducing valve of FIG. 1. FIG. [Figure 5] 2 is a cross-sectional view showing a state in which the valve element has moved toward the seating portion in the pressure reducing valve of FIG. 1. FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a pressure reducing valve according to a second embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a pressure reducing valve according to a third embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a pressure reducing valve according to a fourth embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing a pressure reducing valve according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, pressure reducing valves 1, 1A to 1C according to first to fourth embodiments of the present disclosure will be described with reference to the drawings. Note that the concepts of directions used in the following description are used for convenience of explanation and do not limit the orientation of the configuration of the invention to those directions. Furthermore, the pressure reducing valves 1, 1A to 1C described below are merely one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the following embodiments, and additions, deletions, and modifications are possible within the scope of the invention.

[0013] <Reducing valve> As shown in Fig. 1, a pressure reducing valve 1, which is a first embodiment and an example of a valve device, includes a casing 10, a valve element 11, and a leaf spring 12. The pressure reducing valve 1 reduces the pressure of gases such as compressed natural gas and hydrogen gas to operating pressure or atmospheric pressure.

[0014] <Casing> The casing 10 has a valve passage 13 and a valve space 14. More specifically, the casing 10 has a housing block portion 10a and a cover portion 10b. The valve passage 13 is formed in the housing block portion 10a. The valve space 14 is formed within the casing 10 by covering the housing block portion 10a with the cover portion 10b.

[0015] The valve passage 13 has a primary passage 21, a valve chest 22, and a secondary passage 23. In the valve passage 13, gas flowing from the primary passage 21 passes through the valve chest 22 and is output to the secondary passage 23. More specifically, the primary passage 21 and the valve chest 22 are both formed along a predetermined axis L1. The valve chest 22 is located on one axial side of the primary passage 21, and the primary passage 21 is connected to the valve chest 22 via a valve port 21a. The axial direction is along the axis L1. A seat 24 is formed in the casing 10 around the valve port 21a. The secondary passage 23 opens to the inner circumferential surface of the valve chest 22 and is connected to the valve chest 22. The secondary passage 23 extends from the inner circumferential surface of the valve chest 22 in a direction intersecting the axis L1.

[0016] The valve space 14 is formed within the casing 10. More specifically, the valve space 14 is formed on one axial side of the valve chamber 22 in the casing 10. The valve space 14 is connected to the valve chamber 22. The valve space 14 is separated into an atmospheric chamber 25 and a secondary chamber 26 by a leaf spring 12, which will be described in detail later.

[0017] <Valve body> The valve disc 11 is housed in the casing 10. More specifically, the valve disc 11 is inserted into the valve chamber 22 of the casing 10 so as to be axially movable. The valve disc 11 is, for example, a cylindrical member molded from synthetic resin. A seal member 27 is disposed on the outer circumferential surface of the valve disc 11. The valve disc 11 is inserted into the valve chamber 22 while sealed by the seal member 27. This provides a tight seal between the valve chamber 22 and the valve space 14. One axial end of the valve disc 11 protrudes into the valve space 14. A leaf spring 12, which will be described in detail later, is attached to one axial end of the valve disc 11. The valve disc 11 is disposed so that the tip portion 11a, which is the other axial end, faces the seat portion 24.

[0018] Furthermore, the valve element 11 adjusts the opening degree of the valve passage 13 in accordance with the force acting thereon (secondary pressure, which will be described later in this embodiment). More specifically, the valve element 11 is inserted into the valve chamber 22 so as to be movable in the axial direction. An annular passage 22a is formed around the tip end 11a of the valve element 11. Therefore, the primary side passage 21 is connected to the secondary side passage 23 via the annular passage 22a. Furthermore, the valve element 11 moves toward and away from a seating portion 24. As a result, the opening degree of the valve port 21a of the primary side passage 21 is adjusted by the valve element 11. That is, by moving the valve element 11, the opening degree of the valve passage 13 is adjusted.

[0019] A communication passage 11b is formed in the valve body 11. The communication passage 11b is a passage that penetrates the valve body 11. More specifically, the communication passage 11b opens at the other axial end side of the outer peripheral surface of the valve body 11 and also opens at one axial end side. The communication passage 11b connects the annular passage 22a and the valve space 14 (more specifically, the secondary chamber 26, which will be described in detail later).

[0020] <Leaf springs> The leaf spring 12, which is an urging member, is housed in the casing 10. More specifically, the leaf spring 12 is housed in the valve space 14 of the casing 10. The leaf spring 12 is attached to the valve element 11. The leaf spring 12 extends radially outward from the valve element 11. The leaf spring 12 urges the valve element 11 in one axial direction (in this embodiment, the opening direction, which moves the valve element 11 away from the seating portion 24).

[0021] The configuration of the leaf spring 12 will be described in more detail below. The leaf spring 12 is, for example, a plate-shaped metal member (in this embodiment, a member made of SUS or an alloy such as SUS304CSP). The leaf spring 12 has the following shape: The leaf spring 12 is formed into a disk shape in a plan view. As shown in FIG. 2, the radial center portion (hereinafter referred to as the "center portion") 12a of the leaf spring 12 is formed into a convex cross section that is raised in one axial direction. The center portion 12a of the leaf spring 12 has a larger diameter than the outer shape of the valve body 11 and is formed flat. Furthermore, the outer edge portion 12b of the leaf spring 12 extends radially outward from the valve space 14 in a plan view. The outer edge portion 12b of the leaf spring 12 is formed flat. In this embodiment, the outer edge portion 12b of the leaf spring 12 extends approximately straight in the radial direction.

[0022] The leaf spring 12 also has a tapered portion 12c connecting the outer edge portion 12b and the central portion 12a. The tapered portion 12c is formed as follows. That is, the tapered portion 12c is formed in a tapered shape. The tapered portion 12c is formed in a tapered shape, for example, at a plurality of angles. The tapered portion 12c has different taper angles between the outer edge portion 12d and the central portion 12e. In this embodiment, the taper angle of the central portion 12e is acuter than the taper angle of the outer edge portion 12d. Therefore, when the central portion 12a moves in the other axial direction, the leaf spring 12 bends as follows. That is, the tapered portion 12c compresses and deforms while changing the relative angle between the outer edge portion 12d and the central portion 12e (see the two-dot chain line in FIG. 2). As a result, the central portion 12a moves parallel to the other axial direction while the outer edge portion 12d maintains its shape. It should be noted that the tapered portion 12c does not necessarily have to be formed in a tapered shape with multiple angles, that is, the tapered portion 12c may be formed with a single taper angle.

[0023] As described above, the leaf spring 12 is attached to one axial end of the valve body 11. In this embodiment, the surface on the other axial side of the central portion 12a is joined to one axial end of the valve body 11. The leaf spring 12 also has an insertion hole 12f formed in the central portion 12a. The insertion hole 12f is formed to correspond to the opening of the communication passage 11b at one axial end of the valve body 11 (hereinafter referred to as the "secondary side opening"). In this embodiment, the insertion hole 12f is formed to have a larger diameter than the secondary side opening.

[0024] The following methods are examples of attachment methods. That is, a surface treatment is applied to the surface on the other axial side of the central portion 12a. Examples of surface treatments include chemical treatment and physical treatment using laser irradiation. After the surface treatment, the valve body 11 made of a synthetic resin such as PEEK, PPS, PI, or PAI is resin-molded and joined to the surface on the other axial side of the central portion 12a. Other possible attachment methods include attachment using a snap fit, adhesive, adhesive tape, or bushing, or attachment by chemical bonding or outsert molding. In these attachment methods, it is preferable to ensure sealing between the valve body 11 and the leaf spring 12 using a sealing member or the like.

[0025] Furthermore, when the valve body 11 is molded by resin molding, the valve body 11 is molded with resin so that a gate remainder 11c is formed at one axial end of the valve body 11, as shown in FIG. 3 . More specifically, the insertion hole 12f of the leaf spring 12 is formed with a larger diameter than the communication passage 11b, as described above. The gate remainder 11c is formed on one axial end face of the valve body 11 during resin molding so as to be located within the insertion hole 12f around the secondary-side opening of the valve body 11. The tip of the gate remainder 11c is formed lower than the surface on one axial side of the leaf spring 12. In this embodiment, a counterbore 11e recessed toward the other axial side is formed around the secondary-side opening at one axial end (more specifically, one axial end) of the valve body 11. The gate remainder 11c is formed in the counterbore 11e. This prevents the tip of the gate remainder 11c from exceeding the surface on one axial side of the leaf spring 12, even if the gate remainder 11c is formed long in the axial direction. This prevents the gate remnant 11c from hitting the ceiling surface 14a of the casing 10.

[0026] Furthermore, as shown in FIG. 4 , the leaf spring 12 is fixed to the casing 10. More specifically, an outer edge portion 12b of the leaf spring 12 is fixed to the casing 10 over the entire circumferential direction. More specifically, an outer fixing portion 12g (i.e., the outer edge of the outer edge portion 12b) located radially outward of the leaf spring 12 is fixed. In this embodiment, the leaf spring 12 is fixed to the casing 10 by sandwiching the outer fixing portion 12g over the entire circumferential direction between the cover portion 10b and the housing block portion 10a. More specifically, the outer edge portion 12b of the leaf spring 12 is placed on an end face of the housing block portion 10a. The cover portion 10b is then placed over the housing block portion 10a so that their end faces are butted against each other. In this embodiment, the cover portion 10b is screwed to the housing block portion 10a. As a result, the outer edge of the leaf spring 12 is sandwiched between the end faces of the cover portion 10b and the housing block portion 10a. The cover portion 10b and the housing block portion 10a may be fastened together with a plurality of fasteners (for example, bolts). By fastening together, the outer edge of the leaf spring 12 is sandwiched between the cover portion 10b and the housing block portion 10a. The leaf spring 12 thus arranged biases the valve element 11 in the opening direction against the secondary pressure.

[0027] 1, the leaf spring 12 forms a secondary chamber 26 and an atmospheric chamber 25 in the casing 10. More specifically, the leaf spring 12 separates the valve space 14 of the casing 10, thereby forming the atmospheric chamber 25 and the secondary chamber 26 in the casing 10.

[0028] The secondary chamber 26 is a chamber into which the secondary pressure is introduced, and the introduced secondary pressure acts on the valve element 11. The secondary chamber 26 is located on one axial side of the leaf spring 12. In this embodiment, the secondary chamber 26 is mainly formed in the cover portion 10b. As described above, the secondary chamber 26 is isolated from the atmospheric chamber 25 by the leaf spring 12. On the other hand, the secondary chamber 26 is connected to the valve passage 13 (more specifically, the annular passage 22a) via the communication passage 11b of the valve element 11. Therefore, the secondary pressure is introduced to the secondary chamber 26 via the communication passage 11b. The leaf spring 12 receives the secondary pressure introduced to the secondary chamber 26. The secondary pressure acts on the valve element 11 in the other axial direction via the leaf spring 12. The leaf spring 12 is then deflected by receiving the secondary pressure. The leaf spring 12 then exerts an elastic restoring force to bias the valve element 11 in one axial direction.

[0029] The atmospheric chamber 25 is a chamber maintained at atmospheric pressure to allow compressive deformation of the leaf spring 12 in the axial direction. The atmospheric chamber 25 is located on the opposite side of the leaf spring 12 from the secondary chamber 26, i.e., on the other axial side. That is, the atmospheric chamber 25 is located on the valve chamber 22 side of the leaf spring 12. The atmospheric chamber 25 is open to the atmosphere. More specifically, an atmosphere release passage 25a is formed in the casing 10. The atmosphere chamber 25 is open to the atmosphere via the atmosphere release passage 25a. That is, the atmosphere chamber 25 is maintained at atmospheric pressure. Therefore, the atmosphere chamber 25 allows compressive deformation of the leaf spring 12 in the axial direction.

[0030] Furthermore, the leaf spring 12 is housed in a casing 10. The leaf spring 12 is compressed and deformed in the axial direction at least when the secondary pressure is equal to atmospheric pressure (i.e., in an unpressurized state). More specifically, the casing 10 is configured as follows: In the casing 10, the secondary chamber 26 is formed with a smaller diameter than the atmospheric chamber 25. That is, the inner circumferential surface of the casing 10 has a step 10c on the secondary chamber 26 side, as shown in FIG. 4. More specifically, the inner circumferential surface of the cover portion 10b protrudes radially inward from the inner circumferential surface of the housing block portion 10a. As a result, the step 10c is formed around the entire circumferential circumference of the casing 10 between the cover portion 10b and the housing block portion 10a. The end face on the other axial side of the step 10c is tapered. More specifically, the end face on the other axial side of the step 10c is inclined so as to protrude in the other axial direction as it advances radially inward. As a result, the adjacent portion 12h of the outer edge portion 12b of the leaf spring 12, which is adjacent to the outer fixed portion 12g, is pressed against the step 10c over the entire circumferential direction, and the leaf spring 12 is pressed in the other axial direction and is compressed and deformed in the axial direction.

[0031] As shown in FIG. 3, the leaf spring 12 is compressed and deformed in the axial direction by having the central portion 12a pressed against the casing 10. More specifically, the casing 10 presses the surface of one axial side of the central portion 12a of the leaf spring 12. In this embodiment, the casing 10 is configured as follows: In the casing 10, the central portion 12a of the leaf spring 12 abuts against the ceiling surface 14a of the valve space 14. More specifically, in the casing 10, the ceiling height H (corresponding to the height of the secondary chamber 26, see FIG. 1) from the outer fixing portion 12g to the ceiling surface 14a is lower than the free height h of the leaf spring 12 (see FIG. 2). Therefore, the central portion 12a of the leaf spring 12 abuts against the ceiling surface 14a. This causes the leaf spring 12 to be compressed and deformed in the axial direction (see the two-dot chain line and solid line in FIG. 3). As an example, the ceiling height H is set to 30% to 70% of the free height h.

[0032] <Reducing valve operation> In the pressure reducing valve 1 configured as described above, the valve element 11 is biased in one axial direction by the leaf spring 12 as shown in FIG. 1 . Therefore, the valve passage 13 is open. As a result, gas is output from the primary passage 21 through the annular passage 22a of the valve chamber 22 to the secondary passage 23. The gas is also guided from the annular passage 22a to the secondary chamber 26 via the communicating passage 11b. That is, secondary pressure is guided to the secondary chamber 26. Therefore, when the secondary pressure exceeds a predetermined pressure, the leaf spring 12 moves the valve element 11 to a position corresponding to the secondary pressure as shown in FIG. 5 . As a result, the opening of the valve passage 13 (more specifically, the opening of the valve port 21a) is adjusted according to the secondary pressure. The pressure reducing valve 1 maintains the secondary pressure at the predetermined pressure.

[0033] In addition, in the pressure reducing valve 1, the valve element 11 reciprocates in one axial direction and the other to adjust the opening of the valve passage 13. When the valve element 11 reciprocates in one axial direction and the other, the leaf spring 12 repeatedly undergoes compressive deformation and elastic recovery. As a result, the leaf spring 12 repeatedly oscillates in the axial direction, and an oscillating load acts on the leaf spring 12 (more specifically, the adjacent portion 12h). In this regard, in the pressure reducing valve 1, the leaf spring 12 is pre-compressively deformed in an unpressurized state. In other words, an initial load acts on the leaf spring 12. Therefore, it is possible to reduce the difference between the load acting on the leaf spring 12 in an unpressurized state where the secondary pressure has increased and the load acting on the leaf spring 12 in an applied pressure state. This makes it possible to reduce the load amplitude of the load acting on the leaf spring 12 during operation.

[0034] In the pressure reducing valve 1 of the first embodiment, the leaf spring 12 is compressed and deformed in the axial direction. That is, an initial load can be applied to the leaf spring 12 in the axial direction before the valve element 11 is actuated. Therefore, when the valve element 11 reciprocates, the amount of change in the load acting on the leaf spring 12 can be suppressed. That is, the load amplitude generated in the leaf spring 12 can be reduced. This can improve the durability of the leaf spring 12.

[0035] Furthermore, in the pressure reducing valve 1 of the first embodiment, the leaf spring 12 is compressed and deformed in the axial direction by the casing 10. Therefore, an increase in the number of parts is suppressed.

[0036] Furthermore, in the pressure reducing valve 1 of the first embodiment, the adjacent portion 12h is pressed by the casing 10, thereby compressing and deforming the leaf spring 12 in the axial direction. Therefore, a load can be applied in advance to the adjacent portion 12h, where the load amplitude increases when the valve element 11 operates. This reduces the amount of change in load when the valve element 11 reciprocates. In other words, the load amplitude can be reduced.

[0037] Furthermore, in the pressure reducing valve 1 of the first embodiment, the central portion 12a is pressed by the casing 10, thereby compressing and deforming the leaf spring 12 in the axial direction. Therefore, when the valve body 11 reciprocates, the load amplitude is prevented from increasing.

[0038] Furthermore, in the pressure reducing valve 1 of the first embodiment, the valve element 11 is attached to the central portion 12a of the leaf spring 12. This makes it easy to align the direction in which the leaf spring 12 is pressed with the direction in which the valve element 11 moves. This makes it possible to prevent uneven contact during the reciprocating motion of the valve element 11, allowing the valve element 11 to move smoothly.

[0039] Furthermore, in the pressure reducing valve 1 of the first embodiment, the valve element 11 has a gate remainder 11c at one axial end thereof. This prevents the gate remainder 11c from hitting the seating portion 24 when the valve element 11 operates. This prevents a decrease in the seating property of the seating portion 24 caused by the gate remainder.

[0040] [Second embodiment] The pressure reducing valve 1A of the second embodiment shown in Fig. 6 has a configuration similar to that of the pressure reducing valve 1 of the first embodiment. Regarding the configuration of the pressure reducing valve 1A of the second embodiment, differences from the pressure reducing valve 1 of the first embodiment will be mainly described, and the same components will be assigned the same reference numerals and descriptions thereof will be omitted. The same applies to pressure reducing valves 1B and 1C of the third and fourth embodiments described later. In the pressure reducing valve 1A of the second embodiment, the communication passage 11Ab of the valve body 11A has a throttle 11g. More specifically, the communication passage 11Ab has a first passage portion 11d and a plurality of second passage portions 11e (two second passage portions 11e in this embodiment). The first passage portion 11d extends in the axial direction of the valve body 11. The first passage portion 11d opens at one axial end of the valve body 11 and is connected to the secondary chamber 26. Each of the second passage portions 11e extends in the radial direction from the other axial end of the valve body 11. Each of the second passage portions 11e opens at the other axial end of the outer peripheral surface of the valve body 11 and is connected to the annular passage 22a. Each of the second passage portions 11e is connected radially inward to the first passage portion 11d via a throttle 11g. In this embodiment, the orifice 11g is formed in a tapered shape that narrows radially inward. Therefore, the width of the communication passage 11Ab is narrowed at the orifice 11g, and transmission of pressure fluctuations when the secondary pressure is introduced into the secondary chamber 26 is suppressed. In the pressure reducing valve 1A of the second embodiment, the communication passage 11Ab has a restriction 11g. This makes it possible to suppress the secondary pressure vibration and surge pressure in the secondary pressure from being transmitted to the secondary chamber 26. This prevents the leaf spring 12 and the valve element 11 from being affected by the secondary pressure vibration and surge pressure. This prevents the valve element 11 from chattering. In addition, the pressure reducing valve 1A of the second embodiment has the same functions and effects as the pressure reducing valve 1 of the first embodiment.

[0041] [Third embodiment] In a pressure reducing valve 1B of a third embodiment shown in FIG. 7, a communication passage 11Bb of a valve body 11B has a throttle 11g. More specifically, the communication passage 11Bb has a first passage portion 11d and a plurality of second passage portions 11Be (four second passage portions 11Be in this embodiment). Each of the second passage portions 11Be extends radially from the other axial end of the valve body 11. Each of the second passage portions 11Be opens at the other axial end of the outer peripheral surface of the valve body 11 and is connected to the annular passage 22a. Each of the second passage portions 11e is connected radially inward to the first passage portion 11d. A throttle member 11f is inserted into the second passage portion 11e. The throttle member 11f is formed in a cylindrical shape, and its inner hole forms the throttle 11g. Therefore, the throttle 11g is formed in the second passage portion 11e. In the communication passage 11Bb, the passage width is narrowed at the throttle 11g, so that the communication passage 11Bb also suppresses the transmission of pressure fluctuations when the secondary pressure is introduced into the secondary chamber .

[0042] The pressure reducing valve 1B of the third embodiment has the same functions and effects as the pressure reducing valve 1A of the second embodiment.

[0043] [Fourth embodiment] In a pressure reducing valve 1C of a fourth embodiment shown in FIG. 8, a communication passage 11Cb of a valve body 11C has a throttle 11g. More specifically, the communication passage 11Cb has a first passage portion 11d and a plurality of second passage portions 11Be (four second passage portions 11Be in this embodiment). A throttle member 11Cf is inserted into the first passage portion 11d. The throttle member 11Cf is formed in a cylindrical shape, and its inner hole forms the throttle 11g. Therefore, the throttle 11g is formed in the first passage portion 11d. The communication passage 11Cb also has a narrowed passage width at the throttle 11g. Therefore, the communication passage 11Cb also suppresses the transmission of pressure fluctuations when the secondary pressure is introduced into the secondary chamber 26.

[0044] The pressure reducing valve 1C of the fourth embodiment has the same functions and effects as the pressure reducing valve 1B of the third embodiment.

[0045] [Other embodiments] In this embodiment, the pressure reducing valve 1 has been described as an example of a valve device, but the valve device is not limited to the pressure reducing valve 1. The valve device may be, for example, an on-off valve or a relief valve, as long as it biases the valve element 11 in the axial direction against gas pressures such as primary and secondary pressures. Such a valve device also achieves the same effects as the pressure reducing valve 1. Specifically, the leaf spring 12 is axially compressed and deformed by the casing 10. This means that an axial preload can be applied to the leaf spring 12 before the valve element 11 is actuated. This reduces the amount of change in the load acting on the leaf spring 12 as the valve element 11 reciprocates. This means that the load amplitude acting on the leaf spring 12 can be reduced. This improves the durability of the leaf spring 12. Note that in the valve device, the one axial direction is not necessarily limited to the open direction and may also be the closed direction. Furthermore, while the leaf spring 12 abuts against the ceiling surface 14a in the pressure reducing valve 1, it may be spaced from the ceiling surface 14a, as in a pressure reducing valve 1D shown in FIG. 9 . On the other hand, in the pressure reducing valve 1, the step 10c is formed in the casing 10 to forcibly compress and deform the leaf spring 12, but the step 10c does not have to be present. That is, the leaf spring 12 only needs to be compressively deformed by at least one of the ceiling surface 14a and the step 10c. Furthermore, the portion of the leaf spring 12 that presses the adjacent portion 12h is not necessarily limited to the step 10c, but may be a protrusion. The step 10c may be a separate member from the cover portion 10b. Even if the step 10c is the cover portion 10b, it is included in the casing 10.

[0046] Furthermore, the leaf spring 12 does not necessarily have to be attached to the end face of the valve disc 11, but may be attached to the side of the valve disc 11. Furthermore, the leaf spring 12 is not limited to the shape described above, but may have any plate shape (e.g., rectangular) extending radially outward from the valve disc 11. Furthermore, the leaf spring 12 does not necessarily have to have a pressure-receiving function or a sealing function, but these functions may be achieved by the valve disc 11 or a separate member. In other words, a pressure-receiving portion may be formed on the valve disc 11, or sealing may be achieved using an O-ring or a diaphragm. Furthermore, the valve disc 11 is not necessarily limited to being made of synthetic resin, but may also be made of metal.

[0047] Furthermore, the shape of the valve passage 13 is not limited to the above-described shape. For example, the secondary-side passage 23 may be connected to the secondary chamber 26. Furthermore, the valve element 11 does not necessarily have to be formed with the communication passage 11b shown in FIG. 1 to guide the secondary pressure to the secondary chamber 26. For example, the casing 10 may be formed with a passage that connects the secondary-side passage 23 (or the annular passage 22a) and the secondary chamber 26. Alternatively, the secondary-side passage 23 may be connected to the secondary chamber 26 via a passage and an external pipe.

[0048] In the pressure reducing valves 1B, 1C of the third and fourth embodiments, the throttles 11g are formed by inserting the throttle members 11f, 11Cf into the passage portions 11Be, 11d, respectively, but the throttles may be formed directly in the passage portions 11Be, 11d. Furthermore, the throttle 11g of the pressure reducing valve 1C of the fourth embodiment may be formed in a tapered shape, similar to the pressure reducing valve 1A of the second embodiment.

[0049] Exemplary Embodiments In a first aspect, the pressure reducing valve comprises a casing in which a valve passage is formed, a valve element housed in the casing so as to be axially movable and which adjusts the opening of the valve passage in accordance with a secondary pressure, and a biasing member housed in the casing and biasing the valve element in one axial direction against the secondary pressure, the biasing member being a plate-shaped spring extending radially outward from the valve element and being compressed and deformed in the axial direction at least when the secondary pressure is equal to atmospheric pressure.

[0050] According to the above aspect, the biasing member is compressively deformed in the axial direction. That is, an initial load can be applied to the biasing member in the axial direction before the valve element is actuated. Therefore, when the valve element reciprocates, the amount of change in the load acting on the biasing member can be suppressed. That is, the load amplitude generated in the biasing member can be reduced. This improves the durability of the biasing member.

[0051] In a second aspect of the pressure reducing valve, in the first aspect, the biasing member is compressed and deformed in the axial direction by the casing.

[0052] According to the above aspect, the biasing member is compressed and deformed in the axial direction by the casing, which prevents an increase in the number of parts.

[0053] In a third aspect, the pressure reducing valve is the pressure reducing valve of the second aspect, wherein the biasing member has an outer fixed portion on the radially outer side fixed to the casing, and an adjacent portion on the radially inner side of the outer fixed portion is pressed against the casing, thereby being compressed and deformed in the axial direction.

[0054] According to the above aspect, the biasing member is compressed and deformed in the axial direction by the adjacent portion being pressed by the casing. Therefore, a load can be applied in advance to the adjacent portion where the load amplitude increases when the valve element operates. This reduces the amount of change in load when the valve element reciprocates. In other words, the load amplitude can be reduced.

[0055] In a fourth aspect, in the pressure reducing valve of the second or third aspect, the biasing member is formed in a convex shape with a radially central portion protruding in one axial direction, and the radially central portion is compressed and deformed in the axial direction by being pressed by the casing.

[0056] According to the above aspect, the radially central portion of the biasing member is pressed by the casing, so that the biasing member is compressed and deformed in the axial direction, thereby making it possible to reduce the load amplitude when the valve body reciprocates.

[0057] In a fifth aspect, in the pressure reducing valve of the fourth aspect, the valve element is attached to a radially central portion of the biasing member.

[0058] According to the above aspect, the valve element is attached to the radial center portion of the biasing member. This makes it easy to align the direction in which the biasing member is pushed with the direction in which the valve element moves. This makes it possible to prevent the valve element from hitting one side when reciprocating, thereby enabling the valve element to move smoothly.

[0059] In a sixth aspect, in the pressure reducing valve of any one of the first to fifth aspects, the casing includes a seating portion on which the valve element is seated, and the valve element has a gate residue generated during molding at one axial end portion, and closes the valve passage by seating the other axial end portion on the seating portion.

[0060] According to the above aspect, the biasing member is compressed and deformed in the axial direction by the adjacent portion being pressed by the casing. Therefore, a load can be applied in advance to the adjacent portion where the load amplitude increases when the valve element operates. This reduces the amount of change in load when the valve element reciprocates. In other words, the load amplitude can be reduced.

[0061] A pressure reducing valve in a seventh aspect is the pressure reducing valve of any one of the first to sixth aspects, wherein the casing includes a secondary chamber, the valve element includes a communication passage that introduces a secondary pressure to the secondary chamber, the biasing member receives the secondary pressure introduced to the secondary chamber and moves the valve element to a position according to the received secondary pressure, and the communication passage has a throttle.

[0062] According to the above aspect, the communication passage that introduces the secondary pressure to the secondary chamber has a throttle. This makes it possible to suppress the secondary pressure vibration and surge pressure in the secondary pressure from being transmitted to the secondary chamber. This prevents the biasing member and the valve body from being affected by the secondary pressure vibration and surge pressure. This prevents the valve body from chattering.

[0063] In an eighth aspect, the valve device comprises a casing in which a valve passage is formed, a valve disc housed in the casing so as to be axially movable and which changes its position in response to an acting force to change the opening degree of the valve passage, and a biasing member housed in the casing and biasing the valve disc in one axial direction so as to open the valve passage against the acting force, the biasing member being a plate-shaped spring extending laterally from the valve disc and being compressed and deformed in the axial direction by the casing.

[0064] According to the above aspect, the biasing member is compressively deformed in the axial direction by the casing. That is, an initial load can be applied to the biasing member in the axial direction before the valve element is actuated. Therefore, when the valve element reciprocates, the amount of change in the load acting on the biasing member can be suppressed. That is, the load amplitude acting on the biasing member can be reduced. This improves the durability of the biasing member.

[0065] A pressure reducing valve in a ninth aspect is the pressure reducing valve of the eighth aspect, wherein the casing includes a secondary chamber, the valve element includes a communication passage that introduces secondary pressure to the secondary chamber, the biasing member receives the secondary pressure introduced to the secondary chamber and moves the valve element to a position according to the received secondary pressure, and the communication passage has a throttle.

[0066] According to the above aspect, the communication passage that introduces the secondary pressure to the secondary chamber has a throttle. This makes it possible to suppress the secondary pressure vibration and surge pressure in the secondary pressure from being transmitted to the secondary chamber. This prevents the biasing member and the valve body from being affected by the secondary pressure vibration and surge pressure. This prevents the valve body from chattering.

[0067] From the above description, many modifications and other embodiments of the present invention 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 for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention. [Explanation of symbols]

[0068] 1 Pressure reducing valve 1A Pressure reducing valve 10 Casing 11 Valve body 11c Gate Remaining 12 Leaf spring (biasing member) 12a central part 12g outer fixing part 12h Adjacent part 13 Valve passage 24 seating area

Claims

1. a casing in which a valve passage is formed; a valve element that is housed in the casing so as to be axially movable and that adjusts the opening degree of the valve passage in response to a secondary pressure; a biasing member that is housed in the casing and biases the valve body in one axial direction against the secondary pressure, a pressure reducing valve, wherein the biasing member is a plate-shaped spring extending radially outward from the valve body, and is compressed and deformed in the axial direction at least when the secondary pressure is equal to atmospheric pressure;

2. The pressure reducing valve according to claim 1 , wherein the biasing member is axially compressed and deformed by the casing.

3. 3. The pressure reducing valve according to claim 2, wherein the biasing member has an outer fixed portion on the radially outer side fixed to the casing, and an adjacent portion on the radially inner side of the outer fixed portion is pressed by the casing and is thereby compressed and deformed in the axial direction.

4. 4. The pressure reducing valve according to claim 2, wherein the biasing member has a radially central portion formed in a convex shape that protrudes in one axial direction, and the radially central portion is compressed and deformed in the axial direction by being pressed by the casing.

5. The pressure reducing valve according to claim 4 , wherein the valve body is attached to a radially central portion of the biasing member.

6. the casing includes a seating portion on which the valve body is seated, 2. The pressure reducing valve according to claim 1, wherein the valve body has a gate residue formed during molding at one axial end thereof, and closes the valve passage by seating the other axial end thereof on the seat portion.

7. the casing includes a secondary chamber; the valve body includes a communication passage that introduces a secondary pressure to the secondary chamber, the biasing member receives the secondary pressure introduced into the secondary chamber and moves the valve body to a position corresponding to the received secondary pressure, The pressure reducing valve according to claim 1 , wherein the communication passage has a restriction.

8. A casing including a secondary chamber and in which a valve passage is formed; a valve element that is housed in the casing so as to be axially movable and that changes its position in response to an applied force to change the opening degree of the valve passage; a biasing member that is housed in the casing and biases the valve body in one axial direction to open the valve passage against an acting force, the valve body includes a communication passage that introduces a secondary pressure to the secondary chamber, the biasing member is a plate-shaped spring that extends laterally from the valve body and is compressed and deformed in the axial direction by the casing, receives the secondary pressure introduced into the secondary chamber, and moves the valve body to a position corresponding to the received secondary pressure, The valve device, wherein the communication passage has a restriction.

9. A casing including a secondary chamber and in which a valve passage is formed; a valve element that is housed in the casing so as to be axially movable and that changes its position in response to an applied force to change the opening degree of the valve passage; a biasing member that is housed in the casing and biases the valve body in one axial direction to open the valve passage against an acting force, the valve body includes a communication passage that introduces a secondary pressure to the secondary chamber, The biasing member is a plate-shaped spring extending laterally from the valve body and compressed and deformed in the axial direction by the casing, receives the secondary pressure introduced into the secondary chamber, and moves the valve body to a position corresponding to the received secondary pressure.

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