Pressure reducing valve

Abstract

To provide a technology which can inhibit a liquid from accumulating in a space between an inner peripheral surface of an outer member and an outer peripheral surface of an inner member while stabilizing an attitude of the inner member.SOLUTION: An inner cylindrical part may include: a first end located at a valve body part side end; a second end located at an end opposite to a valve body part; and an intermediate part located between the first end and the second end. An outer peripheral surface at the intermediate part of the inner cylindrical part may be recessed to the radial inner side of the inner cylindrical part over an entire periphery as seen in a circumferential direction of the inner cylindrical part. A space between the outer peripheral surface at the intermediate part of the inner cylindrical part and an inner peripheral surface of an outer cylindrical part may be wider than a space between the outer peripheral surface at the first end of the inner cylindrical part and the inner peripheral surface of the outer cylindrical part and may be wider than a space between the outer peripheral surface at the second end of the inner cylindrical part and the inner peripheral surface of the outer cylindrical part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a pressure reducing valve. [Background technology]

[0002] Patent Document 1 discloses a pressure reducing valve for adjusting the pressure of gas. The pressure reducing valve of Patent Document 1 includes an outer member and an inner member disposed inside the outer member. The outer member includes a valve seat portion provided with an opening through which gas can pass, and an outer cylindrical portion extending cylindrically from the valve seat portion. The inner member includes a valve body portion that opens and closes the opening of the valve seat portion, and an inner cylindrical portion that extends cylindrically from the valve body portion and is disposed inside the outer cylindrical portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-115820 Summary of the Invention [Problem to be solved by the invention]

[0004] The pressure reducing valve of Patent Document 1 is a valve for adjusting the pressure of a gas. However, if this type of pressure reducing valve is used to adjust the pressure of a liquid, liquid may accumulate between the inner circumferential surface of the outer cylindrical portion and the outer circumferential surface of the inner cylindrical portion due to the action of surface tension. If liquid accumulates in this area, for example in cold regions, the accumulated liquid may freeze, causing the pressure reducing valve to malfunction. Furthermore, the accumulated liquid may expand when it freezes, which may cause the inner member to tilt inside the outer member. Furthermore, even in pressure reducing valves that adjust the pressure of a gas, liquid mixed with the gas may penetrate and accumulate between the inner circumferential surface of the outer cylindrical portion and the outer circumferential surface of the inner cylindrical portion. In this case, the accumulated liquid may freeze, causing the pressure reducing valve to malfunction or the inner member to tilt.

[0005] The present specification provides a technique that can prevent liquid from accumulating between the inner circumferential surface of the outer member and the outer circumferential surface of the inner member while stabilizing the posture of the inner member. [Means for solving the problem]

[0006] The pressure reducing valve disclosed in this specification includes an outer member and an inner member disposed inside the outer member. The outer member may include a valve seat having an opening through which a fluid can pass, and an outer cylindrical portion extending cylindrically from the valve seat. The inner member may include a valve body that opens and closes the opening, and an inner cylindrical portion that extends cylindrically from the valve body and is disposed inside the outer cylindrical portion. The inner cylindrical portion may include a first end located at an end on the valve body side, a second end located at an end opposite to the valve body, and an intermediate portion located between the first end and the second end. The outer peripheral surface of the intermediate portion of the inner cylindrical portion may be recessed radially inward of the inner cylindrical portion around the entire circumferential circumference of the inner cylindrical portion. The distance between the outer peripheral surface of the intermediate portion of the inner cylindrical portion and the inner peripheral surface of the outer cylindrical portion may be wider than the distance between the outer peripheral surface of the first end portion of the inner cylindrical portion and the inner peripheral surface of the outer cylindrical portion, and may also be wider than the distance between the outer peripheral surface of the second end portion of the inner cylindrical portion and the inner peripheral surface of the outer cylindrical portion.

[0007] With this configuration, the outer peripheral surface of the inner cylindrical portion at the intermediate portion is recessed, which makes it possible to prevent liquid (e.g., liquid fuel or water mixed in gaseous fuel) from accumulating between the inner peripheral surface of the outer cylindrical portion and the outer peripheral surface of the inner cylindrical portion at the intermediate portion. Furthermore, even if the gap between the outer peripheral surface of the inner cylindrical portion at the intermediate portion and the inner peripheral surface of the outer cylindrical portion is large, the presence of the first end and second end of the inner cylindrical portion makes it possible to stabilize the position of the inner cylindrical portion inside the outer cylindrical portion. As described above, it is possible to prevent liquid from accumulating between the inner peripheral surface of the outer member and the outer peripheral surface of the inner member while stabilizing the position of the inner member.

[0008] The distance between the outer peripheral surface of the inner cylindrical portion at the first end and the inner peripheral surface of the outer cylindrical portion may be wider than the distance between the outer peripheral surface of the inner cylindrical portion at the second end and the inner peripheral surface of the outer cylindrical portion.

[0009] This configuration can prevent liquid from accumulating between the outer peripheral surface of the first end of the inner cylindrical portion and the inner peripheral surface of the outer cylindrical portion. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view of a pressure reducing valve according to an embodiment. [Figure 2] FIG. [Figure 3] Cross-sectional view of III-III in Figure 2. [Figure 4] IV-IV cross section of Figure 2. [Figure 5] VV cross section of Figure 2. [Figure 6] FIG. [Figure 7] FIG. 10 is a cross-sectional view of a pressure reducing valve according to a modified example. [Figure 8] FIG. 10 is a diagram showing the results of a test example. DETAILED DESCRIPTION OF THE INVENTION

[0011] A pressure reducing valve 2 of the embodiment will be described with reference to the drawings. The pressure reducing valve 2 of the embodiment is a valve for reducing the pressure of a fluid (for example, a liquid such as water or liquid fuel, or a gas such as hydrogen gas). Note that the following description will be given of a pressure reducing valve 2 for reducing the pressure of a liquid. As shown in FIG. 1, the pressure reducing valve 2 of the embodiment includes a main body 4 and a valve body 6.

[0012] The main body 4 includes a first flow path 91, a second flow path 92, a first valve seat portion 10, and a cylindrical main body portion 122. The first flow path 91 and the second flow path 92 are configured to allow liquids such as water and fuel to pass through. The first valve seat portion 10 is provided between the first flow path 91 and the second flow path 92. The cylindrical main body portion 122 extends cylindrically from the first valve seat portion 10. The first valve seat portion 10 and the cylindrical main body portion 122 are configured as a single unit.

[0013] The first flow path 91 is provided upstream of the first valve seat portion 10 in the flow direction of the liquid. The first flow path 91 is connected to a liquid supply source (for example, a fuel pump (not shown)). Liquid is supplied from the liquid supply source to the first flow path 91. The second flow path 92 is provided downstream of the first flow path 91 and the first valve seat portion 10 in the flow direction of the liquid. The second flow path 92 is connected to a liquid supply destination (for example, an engine (not shown)). Liquid is supplied to the liquid supply destination through the second flow path 92.

[0014] The first valve seat portion 10 has a first opening 12 through which liquid can pass. The first opening 12 is provided in the center of the first valve seat portion 10. A first flow path 91 on the upstream side and a second flow path 92 on the downstream side communicate with each other through the first opening 12. The first valve seat portion 10 also has a first seating surface 14. The first seating surface 14 is provided around the first opening 12. The first seating surface 14 is provided on the surface of the first valve seat portion 10 on the first flow path 91 side. The first seating surface 14 faces the first flow path 91.

[0015] Next, the valve element 6 will be described. The valve element 6 is disposed in the first flow path 91. The valve element 6 is disposed so as to face the first opening 12 and the first seating surface 14 of the first valve seat portion 10. The valve element 6 opens and closes the first opening 12 by coming into contact with or moving away from the first seating surface 14. When the first opening 12 is opened, liquid flows from the first flow path 91 to the second flow path 92 through the first opening 12.

[0016] As shown in Figures 1 and 2, the valve body 6 includes an outer valve body 20 (an example of an outer member) and an inner valve body 30 (an example of an inner member). The outer valve body 20 is made of, for example, a resin (such as silicone rubber or synthetic rubber). The outer valve body 20 is disposed so as to face the first opening 12 and the first seating surface 14 of the first valve seat portion 10. The outer valve body 20 abuts against or is spaced apart from the first seating surface 14.

[0017] The outer valve body 20 includes a first tip portion 21, a first cylindrical portion 22 (an example of an outer cylindrical portion), a first base end portion 23, and a third flow path 93. The first tip portion 21, the first cylindrical portion 22, and the first base end portion 23 are integrally configured. The first tip portion 21 faces the first valve seat portion 10. The third flow path 93 is provided inside the first tip portion 21, the first cylindrical portion 22, and the first base end portion 23.

[0018] The first tip portion 21 is configured in a substantially conical shape. In a modified example, the first tip portion 21 may be configured in a substantially elliptical cone shape or a substantially polygonal cone shape. The inner and outer diameters of the first tip portion 21 decrease toward the tip side. The first tip portion 21 has a second opening 24 through which liquid can pass. The second opening 24 is provided in the radial center of the first tip portion 21. The upstream third flow path 93 and the downstream second flow path 92 communicate with each other through the first opening 12 of the first valve seat portion 10 and the second opening 24 of the outer valve body 20.

[0019] The first tip portion 21 also includes a first valve body portion 26 and a second valve seat portion 27. The first valve body portion 26 is provided on the outer peripheral surface side (first valve seat portion 10 side) of the first tip portion 21. The second valve seat portion 27 is provided on the inner peripheral surface side (third flow path 93 side) of the first tip portion 21. A second opening portion 24 is provided in the second valve seat portion 27.

[0020] The first valve body portion 26 faces the first seating surface 14 of the first valve seat portion 10 of the main body 4. The first valve body portion 26 has a first abutment surface 262 that abuts against or is spaced apart from the first seating surface 14. The first abutment surface 262 is provided on the outer peripheral surface of the first tip portion 21 and faces the first seating surface 14. The first abutment surface 262 is provided around the second opening 24.

[0021] The second valve seat portion 27 has a second seating surface 272. The second seating surface 272 is provided around the second opening 24. The second seating surface 272 is provided on the inner circumferential surface of the first tip portion 21, and faces the third flow path 93.

[0022] The first cylindrical portion 22 will be described. The first cylindrical portion 22 extends cylindrically from the first valve body portion 26 and the second valve seat portion 27. The first cylindrical portion 22 is configured in a substantially cylindrical shape. In a modified example, the first cylindrical portion 22 may be configured in a substantially elliptical or polygonal cylindrical shape. In the cross-sections shown in FIGS. 3 to 5, the inner circumferential surface 52 of the first cylindrical portion 22 is configured in a substantially circular shape. In a modified example, the inner circumferential surface 52 of the first cylindrical portion 22 may be configured in a substantially elliptical or polygonal shape. As shown in FIGS. 1 and 2, the first cylindrical portion 22 extends cylindrically from the rear end portion of the first tip portion 21 (the end portion opposite the first valve seat portion 10) toward the rear (upstream side). The first cylindrical portion 22 is located between the first tip portion 21 and the first base end portion 23.

[0023] The first base end 23 is configured in a substantially circular ring shape. In a modified example, the first base end 23 may be configured in a substantially elliptical ring shape or a substantially polygonal ring shape. The first base end 23 extends from the rear end (the end opposite the first tip end 21) of the first cylindrical portion 22 toward the inside in the radial direction of the first cylindrical portion 22. The first base end 23 has a third opening 25 through which a liquid can pass. The third opening 25 is provided in the radial center of the first base end 23. The first flow path 91 and the third flow path 93 communicate with each other through the third opening 25.

[0024] Next, the inner valve body 30 will be described. The inner valve body 30 is made of, for example, a metal (alloy or the like). The inner valve body 30 is disposed in the third flow path 93 inside the outer valve body 20. The inner valve body 30 is disposed so as to face the second opening 24 and the second valve seat portion 27 of the outer valve body 20. The inner valve body 30 opens and closes the second opening 24 by abutting against or moving away from the second valve seat portion 27. When the second opening 24 is opened, liquid flows from the third flow path 93 to the second flow path 92 through the second opening 24 and the first opening 12 of the first valve seat portion 10.

[0025] The inner valve body 30 includes a second tip portion 31, a protruding portion 36, a second cylindrical portion 32 (an example of an inner cylindrical portion), and a spring chamber 35. The second tip portion 31, the protruding portion 36, and the second cylindrical portion 32 are integrally configured. The spring chamber 35 is provided inside the second cylindrical portion 32.

[0026] The second tip portion 31 is configured in a substantially conical shape. In a modified example, the second tip portion 31 may be configured in a substantially elliptical cone shape or a substantially polygonal cone shape. The outer diameter of the second tip portion 31 decreases toward the tip side.

[0027] The second tip portion 31 includes a second valve body portion 33. The second valve body portion 33 is provided on the outer peripheral surface side (the second valve seat portion 27 side) of the second tip portion 31. The second valve body portion 33 faces the second opening portion 24 and the second valve seat portion 27 of the outer valve body 20. The second valve body portion 33 opens and closes the second opening portion 24 by coming into contact with or moving away from the second valve seat portion 27.

[0028] The second valve body portion 33 has a second abutment surface 332 that abuts against or is spaced apart from the second seating surface 272 of the second valve seat portion 27. The second abutment surface 332 is provided on the outer peripheral surface of the second tip portion 31, and faces the second seating surface 272 of the outer valve body 20.

[0029] The protrusion 36 extends from the second tip portion 31 toward the second opening 24 of the outer valve body 20. The protrusion 36 is inserted into the second opening 24 and extends toward the second flow path 92. The protrusion 36 protrudes from the second opening 24 toward the second flow path 92. The protrusion 36 is inserted into the first opening 12 of the first valve seat portion 10.

[0030] Next, the second cylindrical portion 32 will be described. The second cylindrical portion 32 extends cylindrically from the second valve body portion 33. The second cylindrical portion 32 is configured in a substantially cylindrical shape. In a modified example, the second cylindrical portion 32 may be configured in a substantially elliptical or polygonal cylindrical shape. In the cross section shown in FIGS. 3 to 5, the outer peripheral surface 62 of the second cylindrical portion 32 is configured in a substantially circular shape. In a modified example, the outer peripheral surface 62 of the second cylindrical portion 32 may be configured in a substantially elliptical or polygonal shape. As shown in FIGS. 1, 2, and 6, the second cylindrical portion 32 extends cylindrically from the rear end (the end opposite the protrusion 36) of the second tip portion 31 toward the rear (upstream side). The second cylindrical portion 32 is disposed inside the first cylindrical portion 22 of the outer valve body 20.

[0031] The second cylindrical portion 32 has a first end portion 80, a second end portion 82, and an intermediate portion 84. The first end portion 80 is located at the end of the second cylindrical portion 32 on the second tip portion 31 side (the second valve body portion 33 side). The second end portion 82 is located at the end of the second cylindrical portion 32 on the opposite side to the second tip portion 31 (the opposite side to the second valve body portion 33). The intermediate portion 84 is located between the first end portion 80 and the second end portion 82 of the second cylindrical portion 32.

[0032] The outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 is recessed radially inward of the second cylindrical portion 32 around the entire circumferential circumference of the second cylindrical portion 32. The outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 is curved in a concave shape. The curved surface of the outer peripheral surface 62 at the intermediate portion 84 extends from the first end portion 80 to the second end portion 82.

[0033] The outer diameter of the second cylindrical portion 32 varies along the axial direction of the second cylindrical portion 32. The outer diameters of the second cylindrical portion 32 at the first end 80 and the second end 82 are the largest among the outer diameters of the second cylindrical portion 32 that vary in the axial direction. The outer diameter of the intermediate portion 84 of the second cylindrical portion 32 is smaller than the outer diameters of the second cylindrical portion 32 at the first end 80 and the second end 82.

[0034] 3 to 5 , the outer peripheral surface 62 of the second cylindrical portion 32 of the inner valve body 30 faces the inner peripheral surface 52 of the first cylindrical portion 22 of the outer valve body 20 in the radial direction of the second cylindrical portion 32. A gap 60 through which liquid can pass is provided between the outer peripheral surface 62 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22. When liquid passes through the third flow path 93 inside the outer valve body 20, the liquid passes through the gap 60.

[0035] The distance between the outer peripheral surface 62 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 varies along the axial direction of the second cylindrical portion 32. A distance W84 between the outer peripheral surface 62 of the second cylindrical portion 32 at an intermediate portion 84 and the inner peripheral surface 52 of the first cylindrical portion 22 is wider than a distance W80 between the outer peripheral surface 62 of the second cylindrical portion 32 at a first end portion 80 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 (see FIGS. 3 and 4). Furthermore, the distance W84 between the outer peripheral surface 62 of the second cylindrical portion 32 at the intermediate portion 84 and the inner peripheral surface 52 of the first cylindrical portion 22 is wider than a distance W82 between the outer peripheral surface 62 of the second end portion 82 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 (see FIGS. 3 and 5). The distance W80 at the first end 80 and the distance W82 at the second end 82 are the smallest distances that vary in the axial direction between the outer peripheral surface 62 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22. In the embodiment, the distance W80 at the first end 80 and the distance W82 at the second end 82 are the same distance.

[0036] As shown in Fig. 1, a small coil spring 50 is disposed in the spring chamber 35 of the inner valve body 30. The small coil spring 50 expands and contracts along the axial direction of the valve body 6. The small coil spring 50 presses the valve body 6 (the inner valve body 30 and the outer valve body 20) from the upstream side toward the downstream side.

[0037] The pressure reducing valve 2 further includes a piston 100 and a large coil spring 102. The piston 100 is configured to be movable in the left-right direction in FIG. 1. The piston 100 is pressed toward the valve body 6 by the large coil spring 102. The piston 100 includes a protruding portion 101 that protrudes toward the protruding portion 36 of the inner valve body 30.

[0038] Next, the operation of the pressure reducing valve 2 will be described. First, the pressure reducing valve 2 is in a closed state. That is, the valve element 6 is in contact with the first valve seat portion 10 of the main body 4, and the first opening 12 is in a closed state. Furthermore, the inner valve element 30 is in contact with the outer valve element 20, and the second opening 24 is in a closed state. When the pressure reducing valve 2 is in a closed state, the pressure of the liquid in the second flow path 92 is maintained at a relatively high level.

[0039] (Valve opening operation) In the pressure reducing valve 2, when liquid is supplied to a liquid supply destination, the pressure of the liquid in the second flow path 92 decreases. As a result, the piston 100, which receives the pressure of the liquid in the second flow path 92, is pressed toward the valve element 6 by the large coil spring 102, and the piston 100 moves toward the valve element 6. When the pressure of the liquid in the second flow path 92 decreases significantly, the piston 100 accordingly moves significantly toward the valve element 6. On the other hand, when the amount of decrease in the pressure of the liquid in the second flow path 92 is small, the amount of movement of the piston 100 toward the valve element 6 also decreases accordingly.

[0040] As the piston 100 moves toward the valve disc 6, the protruding portion 101 of the piston 100 comes into contact with the protruding portion 36 of the inner valve disc 30 and presses the inner valve disc 30 upstream. This causes the inner valve disc 30 to move upstream. When the piston 100 moves significantly toward the valve disc 6, the inner valve disc 30 moves significantly upstream. On the other hand, when the amount of movement of the piston 100 toward the valve disc 6 is small, the amount of movement of the inner valve disc 30 upstream also becomes small.

[0041] As the inner valve body 30 moves upstream, the second valve body portion 33 of the inner valve body 30 moves away from the second valve seat portion 27 of the outer valve body 20, and the second opening 24 enters an open state. When the second opening 24 enters an open state, liquid flows from the third flow path 93 inside the outer valve body 20 to the second flow path 92 through the second opening 24. This state is the first open valve state. The first open valve state occurs when the pressure difference between the pressure of the liquid in the second flow path 92 and the pressure of the liquid in the first flow path 91 is relatively high. In the first open valve state, the outer valve body 20 is pressed downstream by the pressure of the liquid passing through the third flow path 93. This causes the outer valve body 20 to abut against the first valve seat portion 10 of the main body 4.

[0042] When the inner valve element 30 moves further upstream from the first open state, the second cylindrical portion 32 of the inner valve element 30 abuts against the first base end portion 23 of the outer valve element 20 and presses the first base end portion 23 upstream. This causes the outer valve element 20 to move upstream. As the outer valve element 20 moves upstream, the first valve element portion 26 of the outer valve element 20 moves away from the first seating surface 14 of the first valve seat portion 10, and the first opening 12 enters an open state. When the first opening 12 enters an open state, liquid flows from the first flow path 91 through the first opening 12 to the second flow path 92. This state is the second open state. The second open state occurs when the pressure difference between the pressure of the liquid in the second flow path 92 and the pressure of the liquid in the first flow path 91 is relatively low.

[0043] (Valve closing operation) Next, the valve closing operation will be described. The valve closing operation is the opposite operation to the valve opening operation described above. In the pressure reducing valve 2 described above, when liquid flows into the second flow path 92, the pressure of the liquid in the second flow path 92 increases. Then, the pressure of the liquid in the second flow path 92 presses the piston 100 toward the side opposite the valve body 6, and the piston 100 moves toward the side opposite the valve body 6 (i.e., the downstream side). As the piston 100 moves downstream, the inner valve body 30 also moves downstream.

[0044] As the inner valve body 30 moves downstream, the second valve body portion 33 of the inner valve body 30 abuts against the second valve seat portion 27 of the outer valve body 20, closing the second opening 24. As the inner valve body 30 moves further downstream, the inner valve body 30 presses the outer valve body 20 downstream, causing the inner valve body 30 and the outer valve body 20 to move downstream. As the inner valve body 30 and the outer valve body 20 move downstream, the first valve body portion 26 of the outer valve body 20 abuts against the first valve seat portion 10 of the main body 4, closing the first opening 12.

[0045] (effect) The above has described the pressure reducing valve 2 of the embodiment. As is clear from the above description, in the pressure reducing valve 2 of the embodiment, the inner valve body 30 includes the second valve body portion 33 that opens and closes the second opening 24 of the outer valve body 20, and the second cylindrical portion 32 that extends cylindrically from the second valve body portion 33 and is disposed inside the first cylindrical portion 22 of the outer valve body 20. The second cylindrical portion 32 includes a first end portion 80 located at the end on the second valve body portion 33 side, a second end portion 82 located at the end on the opposite side to the second valve body portion 33 (the end on the first base end portion 23 side of the outer valve body 20), and an intermediate portion 84 located between the first end portion 80 and the second end portion 82. The outer peripheral surface 62 of the intermediate portion 84 of the second cylindrical portion 32 is recessed radially inward of the second cylindrical portion 32 over the entire circumferential circumference of the second cylindrical portion 32. A distance W84 between the outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 is wider than a distance W80 between the outer peripheral surface 62 at the first end portion 80 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22. Furthermore, the distance W84 between the outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 is wider than a distance W82 between the outer peripheral surface 62 at the second end portion 82 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22.

[0046] According to this configuration, the outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 of the inner valve body 30 is recessed inward, thereby making it possible to prevent liquid from accumulating between the outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22. Furthermore, even if the gap between the outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 is wide, the presence of the first end portion 80 and the second end portion 82 of the second cylindrical portion 32 makes it possible to stabilize the orientation of the second cylindrical portion 32 inside the first cylindrical portion 22. As described above, it is possible to prevent liquid from accumulating between the inner peripheral surface 52 of the outer valve body 20 and the outer peripheral surface 62 of the inner valve body 30 while stabilizing the orientation of the inner valve body 30.

[0047] (Variation) (1) The outer diameter at the first end 80 of the second cylindrical portion 32 of the inner valve body 30 may be smaller than the outer diameter at the second end 82 of the second cylindrical portion 32. In other words, the distance W80 between the outer peripheral surface 62 at the first end 80 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 may be larger than the distance W82 between the outer peripheral surface 62 at the second end 82 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22. This configuration makes it possible to prevent liquid from accumulating between the outer peripheral surface 62 at the first end 80 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22.

[0048] (2) In the above embodiment, the outer peripheral surface 62 of the intermediate portion 84 of the second tubular portion 32 is configured as a curved surface, but is not limited to this configuration. In a modified example, the outer peripheral surface 62 of the intermediate portion 84 of the second tubular portion 32 may be configured as a bent surface.

[0049] (3) In the above embodiment, the valve body 6 includes the outer valve body 20, but this configuration is not limited to this. In a modified example, the valve body 6 does not need to include the outer valve body 20. In this case, as shown in FIG. 7 , an inner valve body 30 is disposed in the first flow path 91 of the main body 4. The inner valve body 30 is disposed so as to face the first opening 12 and the first seating surface 14 of the first valve seat portion 10 of the main body 4. The second valve body portion 33 of the inner valve body 30 opens and closes the first opening 12 by abutting against or separating from the first seating surface 14.

[0050] The outer peripheral surface 62 of the second cylindrical portion 32 of the inner valve body 30 faces an inner peripheral surface 152 of a main body cylindrical portion 122 (another example of an outer cylindrical portion) of the main body 4 (another example of an outer member) in the radial direction of the second cylindrical portion 32. The distance between the outer peripheral surface 62 at an intermediate portion 84 of the second cylindrical portion 32 of the inner valve body 30 and the inner peripheral surface 152 of the main body cylindrical portion 122 of the main body 4 is wider than the distance between the outer peripheral surface 62 at a first end portion 80 of the second cylindrical portion 32 and the inner peripheral surface 152 of the main body cylindrical portion 122 of the main body 4. Furthermore, the distance between the outer peripheral surface 62 at the intermediate portion 84 of the second cylindrical portion 32 and the inner peripheral surface 152 of the main body cylindrical portion 122 of the main body 4 is wider than the distance between the outer peripheral surface 62 at a second end portion 82 of the second cylindrical portion 32 and the inner peripheral surface 152 of the main body cylindrical portion 122.

[0051] (4) In the above embodiment, the pressure reducing valve 2 is described as being for reducing the pressure of a liquid, but the present invention is not limited to this configuration. In a modified example, the pressure reducing valve 2 may be for reducing the pressure of a gas (e.g., hydrogen gas, etc.). Even in this case, it is possible to prevent a liquid (e.g., water, etc.) mixed with the gas from remaining between the inner circumferential surface 52 of the outer valve body 20 and the outer circumferential surface 62 of the inner valve body 30.

[0052] (Test example) A comparative test using a test example and a comparative example will be described. The pressure reducing valve of the test example was the pressure reducing valve 2 of the above-mentioned embodiment. The pressure reducing valve of the comparative example was configured such that, compared to the pressure reducing valve 2 of the embodiment, the outer peripheral surface 62 of the intermediate portion 84 of the second cylindrical portion 32 of the inner valve body 30 was not recessed. For the test example and the comparative example, the amount of liquid remaining in the gap 60 between the outer peripheral surface 62 of the intermediate portion 84 of the second cylindrical portion 32 of the inner valve body 30 and the inner peripheral surface 52 of the first cylindrical portion 22 of the outer valve body 20 was compared by simulation.

[0053] The graph shown in FIG. 8 is a graph showing the results of the comparative test. The horizontal axis of the graph shown in FIG. 8 represents the time it takes for the liquid to flow through the gap 60. The vertical axis of the graph represents the ratio of the volume of the liquid retained in the gap 60 facing the outer peripheral surface 62 of the intermediate portion 84 of the second cylindrical portion 32 to the volume of the first flow path 91 and the third flow path 93. As shown in FIG. 8, it was confirmed that the amount of liquid retained in the gap 60 facing the outer peripheral surface 62 of the intermediate portion 84 of the second cylindrical portion 32 in the test example (pressure reducing valve 2 of the example) was approximately 45% less than that of the pressure reducing valve of the comparative example. From the above, it was confirmed that the pressure reducing valve of the test example (pressure reducing valve 2 of the example) was able to prevent the liquid from retaining between the inner peripheral surface 52 of the outer valve body 20 and the outer peripheral surface 62 of the inner valve body 30.

[0054] Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives itself has technical utility. [Explanation of symbols]

[0055] 2: Pressure reducing valve, 4: Main body, 6: Valve body, 10: Valve seat, 12: First opening, 14: Outer valve seat portion, 20: Outer valve body, 21: First tip portion, 22: First cylindrical portion, 23: First base end portion, 24: Second opening portion, 25: Third opening portion, 26: Outer valve body portion, 27: Inner valve seat portion, 30: Inner valve body, 31: Second tip portion, 32: Second cylindrical portion, 33: Inner valve body portion, 35: spring chamber, 36: protrusion portion, 50: small coil spring, 52: inner circumferential surface, 60: gap, 62: outer circumferential surface, 80: first end portion, 82: second end portion, 84: intermediate portion, 91: first flow path, 92: second flow path, 93: third flow path, 100: piston, 101: protrusion portion, 102: large coil spring, 122: cylindrical portion, 152: inner circumferential surface

Claims

[Claim 1] A pressure reducing valve comprising an outer member and an inner member disposed inside the outer member, the outer member includes a valve seat portion provided with an opening through which a fluid can pass, and an outer cylindrical portion extending cylindrically from the valve seat portion, the inner member includes a valve body portion that opens and closes the opening, and an inner cylindrical portion that extends cylindrically from the valve body portion and is disposed inside the outer cylindrical portion, the inner cylindrical portion includes a first end portion located at an end portion on the valve body portion side, a second end portion located at an end portion opposite the valve body portion, and an intermediate portion located between the first end portion and the second end portion, an outer circumferential surface of the intermediate portion of the inner cylindrical portion is recessed radially inward of the inner cylindrical portion over the entire circumferential circumference of the inner cylindrical portion, a distance between an outer peripheral surface of the intermediate portion of the inner cylindrical portion and an inner peripheral surface of the outer cylindrical portion is wider than a distance between an outer peripheral surface of the inner cylindrical portion at the first end portion of the inner cylindrical portion and an inner peripheral surface of the outer cylindrical portion, and is also wider than a distance between an outer peripheral surface of the inner cylindrical portion at the second end portion of the inner cylindrical portion and an inner peripheral surface of the outer cylindrical portion, a pressure reducing valve, wherein the distance between the outer peripheral surface of the inner cylindrical portion at the first end and the inner peripheral surface of the outer cylindrical portion is wider than the distance between the outer peripheral surface of the inner cylindrical portion at the second end and the inner peripheral surface of the outer cylindrical portion.

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