Pressure reducing valve

Abstract

Provided is a technique whereby it is possible to stabilize the orientation of an inner member and to suppress the retention of liquid between the inner peripheral surface of an outer member and the outer peripheral surface of the inner member. The inner cylindrical portion may have a first end portion located at an end portion on the valve body portion side, a second end portion located at an end portion on the opposite side from the valve body portion, and an intermediate portion located between the first end portion and the second end portion. The outer peripheral surface of the intermediate portion of the inner cylindrical portion may be recessed inward in the radial direction of the inner cylindrical portion over the entire circumference of the inner cylindrical portion in the circumferential direction. Alternatively, the interval between the outer peripheral surface of the inner cylindrical portion at the intermediate portion and the inner peripheral surface of the outer cylindrical portion may be wider than the interval between the outer peripheral surface of the inner cylindrical portion at the first end portion and the inner peripheral surface of the outer cylindrical portion. The distance between the outer peripheral surface of the inner cylindrical part at the second end part and the inner peripheral surface of the outer cylindrical part is wider than the distance between the outer peripheral surface of the inner cylindrical part at the second end part and the inner peripheral surface of the outer cylindrical part.

Description

Technical Field

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

[0002] Patent document 1 discloses a pressure reducing valve for adjusting the pressure of a gas. The pressure reducing valve of Patent document 1 includes an outer member and an inner member arranged inside the outer member. The outer member includes: a valve seat portion having an opening through which gas can pass; and an outer cylindrical portion extending in a cylindrical shape from the valve seat portion. The inner member includes: a valve core portion for opening and closing the opening of the valve seat portion; and an inner cylindrical portion extending in a cylindrical shape from the valve core portion, the inner cylindrical portion being arranged inside the outer cylindrical portion.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-115820 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The pressure reducing valve of patent document 1 is a valve for adjusting the pressure of gas, but in the case where it is assumed that the pressure of liquid is adjusted by using such a pressure reducing valve, sometimes the liquid is retained between the inner peripheral surface of the outer cylindrical portion and the outer peripheral surface of the inner cylindrical portion due to the effect of surface tension. It is conceivable that if the liquid is retained in this portion, for example, in cold areas, the pressure reducing valve may malfunction due to freezing of the retained liquid. In addition, it is conceivable that the posture of the inner member may tilt on the inner side of the outer member due to the expansion of the volume caused by freezing of the retained liquid. In addition, even in the case of a pressure reducing valve for adjusting the pressure of gas, sometimes the liquid mixed in the gas may enter and be retained between the inner peripheral surface of the outer cylindrical portion and the outer peripheral surface of the inner cylindrical portion. It is conceivable that in this case, the pressure reducing valve may malfunction and the posture of the inner member may tilt due to freezing of the retained liquid.

[0008] This specification provides a technology that can stabilize the posture of an inner member and suppress the accumulation of liquid between the inner peripheral surface of an outer member and the outer peripheral surface of the inner member.

[0009] Solutions for solving problems

[0010] The pressure reducing valve disclosed in this specification includes an outer member and an inner member arranged inside the outer member. Alternatively, the outer member includes: a valve seat portion, which is provided with an opening portion through which a fluid can pass; and an outer cylindrical portion, which extends from the valve seat portion in a cylindrical shape. Alternatively, the inner member includes: a valve core portion, which opens and closes the opening portion; and an inner cylindrical portion, which extends from the valve core portion in a cylindrical shape, and the inner cylindrical portion is arranged inside the outer cylindrical portion. Alternatively, the inner cylindrical portion includes: a first end portion, which is located at an end portion on the valve core portion side; a second end portion, which is located at an end portion on the side opposite to the valve core portion; and an intermediate portion, which is located between the first end portion and the second end portion. Alternatively, the outer peripheral surface of the intermediate portion of the inner cylindrical portion is recessed inward in the radial direction of the inner cylindrical portion over the entire circumference of the inner cylindrical portion. It is also possible that the interval between the outer circumferential surface at the middle portion of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion is wider than the interval between the outer circumferential surface at the first end portion of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion, and is wider than the interval between the outer circumferential surface at the second end portion of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion.

[0011] According to this structure, since the outer peripheral surface at the middle part of the inner cylindrical portion of the inner member is recessed, it is possible to suppress liquid (for example, liquid fuel or water mixed in gaseous fuel, etc.) from being retained between the inner peripheral surface of the outer cylindrical portion and the outer peripheral surface at the middle part of the inner cylindrical portion. In addition, even if the interval between the outer peripheral surface at the middle part of the inner cylindrical portion and the inner peripheral surface of the outer cylindrical portion is wide, the presence of the first end and the second end of the inner cylindrical portion can stabilize the posture of the inner cylindrical portion inside the outer cylindrical portion. According to the above, it is possible to stabilize the posture of the inner member and suppress liquid from being retained between the inner peripheral surface of the outer member and the outer peripheral surface of the inner member.

[0012] The distance between the outer circumferential surface at the first end of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion may be wider than the distance between the outer circumferential surface at the second end of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion.

[0013] According to this configuration, it is possible to suppress the liquid from accumulating 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view of the pressure reducing valve of the embodiment.

[0015] Figure 2 It is a cross-sectional view of the valve core of the embodiment.

[0016] Figure 3 yes Figure 2 III-III sectional view.

[0017] Figure 4 yes Figure 2 IV-IV cross-sectional view.

[0018] Figure 5 yes Figure 2 VV cross-sectional view.

[0019] Figure 6 It is a perspective view of the inner valve core of the embodiment.

[0020] Figure 7 It is a cross-sectional view of a pressure reducing valve according to a modified example.

[0021] Figure 8 It is a figure which shows the result of a test example. DETAILED DESCRIPTION

[0022] The pressure reducing valve 2 of the embodiment is described with reference to the accompanying drawings. The pressure reducing valve 2 of the embodiment is a valve for reducing the pressure of a fluid (for example, liquid such as water or liquid fuel, or gas such as hydrogen). In addition, the pressure reducing valve 2 for reducing the pressure of a liquid is described below. Figure 1 As shown, the pressure reducing valve 2 of the embodiment includes a main body 4 and a valve element 6 .

[0023] The main body 4 includes a first flow path 91, a second flow path 92, a first valve seat portion 10, and a main body cylindrical portion 122. The first flow path 91 and the second flow path 92 are configured so that liquids such as water and fuel can pass therethrough. The first valve seat portion 10 is provided between the first flow path 91 and the second flow path 92. The main body cylindrical portion 122 extends from the first valve seat portion 10 in a cylindrical shape. The first valve seat portion 10 and the main body cylindrical portion 122 are configured as one body.

[0024] The first flow path 91 is provided at a position on the upstream side 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 (e.g., a fuel pump (not shown)). Liquid is supplied to the first flow path 91 from the liquid supply source. The second flow path 92 is provided at a position on the downstream side 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 (e.g., an engine (not shown)). Liquid is supplied to the liquid supply destination via the second flow path 92.

[0025] The first valve seat portion 10 includes a first opening portion 12 through which liquid can pass. The first opening portion 12 is provided at the center of the first valve seat portion 10. The first flow path 91 on the upstream side and the second flow path 92 on the downstream side are connected via the first opening portion 12. In addition, the first valve seat portion 10 includes a first seat surface 14. The first seat surface 14 is provided around the first opening portion 12. The first seat surface 14 is provided on the surface of the first valve seat portion 10 on the side of the first flow path 91. The first seat surface 14 faces the first flow path 91.

[0026] Next, the valve core 6 is described. The valve core 6 is arranged in the first flow path 91. The valve core 6 is arranged to face the first opening 12 and the first seat surface 14 of the first valve seat portion 10. The valve core 6 opens and closes the first opening 12 by contacting or separating with respect to the first seat surface 14. When the first opening 12 is opened, the liquid flows from the first flow path 91 to the second flow path 92 via the first opening 12.

[0027] like Figure 1 and Figure 2 As shown, the valve core 6 includes an outer valve core 20 (an example of an outer member) and an inner valve core 30 (an example of an inner member). The outer valve core 20 is made of, for example, resin (silicone rubber, synthetic rubber, etc.). The outer valve core 20 is arranged to be opposite to the first opening 12 of the first valve seat portion 10 and the first seat surface 14. The outer valve core 20 abuts against or separates from the first seat surface 14.

[0028] The outer valve core 20 includes a first top end 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 top end portion 21, the first cylindrical portion 22, and the first base end portion 23 are integrally formed. The first top end portion 21 is opposite to the first valve seat portion 10. The third flow path 93 is provided inside the first top end portion 21, the first cylindrical portion 22, and the first base end portion 23.

[0029] The first top end portion 21 is configured to be roughly conical. In a modified example, the first top end portion 21 may also be configured to be roughly elliptical cone-shaped or roughly polygonal pyramid-shaped. The inner diameter and outer diameter of the first top end portion 21 decrease toward the top end side. The first top end portion 21 has a second opening portion 24 through which liquid can pass. The second opening portion 24 is provided in the radial center portion of the first top end portion 21. The third flow path 93 on the upstream side and the second flow path 92 on the downstream side are connected via the first opening portion 12 of the first valve seat portion 10 and the second opening portion 24 of the outer valve core 20.

[0030] In addition, the first top end portion 21 includes a first valve core portion 26 and a second valve seat portion 27. The first valve core portion 26 is provided on the outer peripheral surface side (first valve seat portion 10 side) of the first top end portion 21. The second valve seat portion 27 is provided on the inner peripheral surface side (third flow path 93 side) of the first top end portion 21. The second opening portion 24 is provided in the second valve seat portion 27.

[0031] The first valve core portion 26 is opposite to the first seat surface 14 of the first valve seat portion 10 of the body 4. The first valve core portion 26 includes a first contact surface 262 that contacts or separates from the first seat surface 14. The first contact surface 262 is provided on the outer peripheral surface of the first top end portion 21 and faces the first seat surface 14. The first contact surface 262 is provided around the second opening portion 24.

[0032] The second valve seat portion 27 includes a second seat surface 272 . The second seat surface 272 is provided around the second opening 24 . The second seat surface 272 is provided on the inner peripheral surface of the first distal end portion 21 , and faces the third flow path 93 .

[0033] The first cylindrical portion 22 is described. The first cylindrical portion 22 extends from the first valve core portion 26 and the second valve seat portion 27 in a cylindrical shape. The first cylindrical portion 22 is configured to be substantially cylindrical. In a modified example, the first cylindrical portion 22 may also be configured to be substantially elliptical cylindrical or substantially polygonal cylindrical. Figure 3-Figure 5 In the cross section shown in FIG. 1 , the inner circumferential surface 52 of the first cylindrical portion 22 is configured to be substantially circular. In a modified example, the inner circumferential surface 52 of the first cylindrical portion 22 may also be configured to be substantially elliptical or substantially polygonal. Figure 1 and Figure 2 As shown, the first tubular portion 22 extends in a tubular shape from the rear end portion (the end portion opposite to the first valve seat portion 10 ) of the first tip portion 21 toward the rear (upstream side). The first tubular portion 22 is located between the first tip portion 21 and the first base portion 23 .

[0034] The first base end portion 23 is configured as a roughly circular ring. In a modified example, the first base end portion 23 can also be configured as a roughly elliptical ring or a roughly polygonal ring. The first base end portion 23 extends from the rear end portion of the first tubular portion 22 (the end on the side opposite to the first top end portion 21) toward the radial inner side of the first tubular portion 22. The first base end portion 23 has a third opening portion 25 through which liquid can pass. The third opening portion 25 is provided at the center portion of the radial direction of the first base end portion 23. The first flow path 91 and the third flow path 93 are connected via the third opening portion 25.

[0035] Next, the inner valve core 30 will be described. The inner valve core 30 is made of, for example, metal (alloy, etc.). The inner valve core 30 is arranged in the third flow path 93 on the inner side of the outer valve core 20. The inner valve core 30 is arranged to be opposite to the second opening portion 24 and the second valve seat portion 27 of the outer valve core 20. The inner valve core 30 opens and closes the second opening portion 24 by abutting or separating with respect to the second valve seat portion 27. When the second opening portion 24 is opened, the liquid flows from the third flow path 93 to the second flow path 92 via the second opening portion 24 and the first opening portion 12 of the first valve seat portion 10.

[0036] The inner valve body 30 includes a second tip portion 31, a protruding portion 36, a second tubular portion 32 (an example of an inner tubular portion), and a spring chamber 35. The second tip portion 31, the protruding portion 36, and the second tubular portion 32 are integrally formed. The spring chamber 35 is provided inside the second tubular portion 32.

[0037] The second distal end portion 31 is configured in a substantially conical shape. In a modified example, the second distal end portion 31 may be configured in a substantially elliptical cone shape or a substantially polygonal pyramid shape. The outer diameter of the second distal end portion 31 decreases toward the distal end side.

[0038] The second top end portion 31 includes a second valve core portion 33. The second valve core portion 33 is provided on the outer peripheral surface side (second valve seat portion 27 side) of the second top end portion 31. The second valve core portion 33 is opposite to the second opening portion 24 and the second valve seat portion 27 of the outer valve element 20. The second valve core portion 33 opens and closes the second opening portion 24 by contacting or separating from the second valve seat portion 27.

[0039] The second valve body portion 33 includes a second contact surface 332 that contacts or separates from the second seat surface 272 of the second valve seat portion 27. The second contact surface 332 is provided on the outer peripheral surface of the second distal end portion 31 and faces the second seat surface 272 of the outer valve body 20.

[0040] The protrusion 36 extends from the second tip portion 31 toward the second opening 24 of the outer valve element 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.

[0041] Next, the second cylindrical portion 32 will be described. The second cylindrical portion 32 extends from the second valve core portion 33 in a cylindrical shape. The second cylindrical portion 32 is configured to be substantially cylindrical. In a modified example, the second cylindrical portion 32 may also be configured to be substantially elliptical cylindrical or substantially polygonal cylindrical. Figure 3-Figure 5 In the cross section shown in FIG. 1 , the outer peripheral surface 62 of the second cylindrical portion 32 is configured to be substantially circular. In a modified example, the outer peripheral surface 62 of the second cylindrical portion 32 may also be configured to be substantially elliptical or substantially polygonal. Figure 1 , Figure 2 as well as Figure 6 As shown, the second tubular portion 32 extends in a tubular shape from the rear end portion (the end opposite to the protrusion 36 ) of the second tip portion 31 toward the rear (upstream). The second tubular portion 32 is disposed inside the first tubular portion 22 of the outer valve element 20 .

[0042] The second tubular portion 32 includes 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 tubular portion 32 on the second tip portion 31 side (the second valve core portion 33 side). The second end portion 82 is located at the end of the second tubular portion 32 on the opposite side to the second tip portion 31 (the opposite side to the second valve core portion 33). The intermediate portion 84 is located between the first end portion 80 and the second end portion 82 of the second tubular portion 32.

[0043] The outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 is recessed inward in the radial direction of the second cylindrical portion 32 over the entire circumference of the second cylindrical portion 32. The outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 is concavely curved. The curved surface of the outer peripheral surface 62 at the middle portion 84 extends from the first end portion 80 to the second end portion 82.

[0044] The outer diameter of the second cylindrical portion 32 changes along the axial direction of the second cylindrical portion 32. The outer diameters at the first end 80 and the second end 82 of the second cylindrical portion 32 are the largest outer diameters among the outer diameters that change along the axial direction of the second cylindrical portion 32. The outer diameter at the middle portion 84 of the second cylindrical portion 32 is smaller than the outer diameters at the first end 80 and the second end 82 of the second cylindrical portion 32.

[0045] like Figure 3-Figure 5 As shown, the outer peripheral surface 62 of the second cylindrical portion 32 of the inner valve core 30 is opposite to the inner peripheral surface 52 of the first cylindrical portion 22 of the outer valve core 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 the liquid passes through the third flow path 93 on the inner side of the outer valve core 20, the liquid passes through the gap 60.

[0046] The interval between the outer circumferential surface 62 of the second tubular portion 32 and the inner circumferential surface 52 of the first tubular portion 22 varies along the axial direction of the second tubular portion 32. The interval W84 between the outer circumferential surface 62 of the middle portion 84 of the second tubular portion 32 and the inner circumferential surface 52 of the first tubular portion 22 is wider than the interval W80 between the outer circumferential surface 62 of the first end portion 80 of the second tubular portion 32 and the inner circumferential surface 52 of the first tubular portion 22 (see FIG. 1 ). Figure 3 and Figure 4 ). In addition, the interval W84 between the outer peripheral surface 62 at the middle portion 84 of the second tubular portion 32 and the inner peripheral surface 52 of the first tubular portion 22 is wider than the interval W82 between the outer peripheral surface 62 at the second end portion 82 of the second tubular portion 32 and the inner peripheral surface 52 of the first tubular portion 22 (refer to Figure 3 and Figure 5). The interval W80 at the first end 80 and the interval W82 at the second end 82 are the smallest intervals among the intervals that vary along the axial direction between the outer circumferential surface 62 of the second tubular portion 32 and the inner circumferential surface 52 of the first tubular portion 22. In the embodiment, the interval W80 at the first end 80 and the interval W82 at the second end 82 are the same intervals.

[0047] like Figure 1 As shown, a small coil spring 50 is arranged in the spring chamber 35 of the inner valve element 30. The small coil spring 50 expands and contracts along the axial direction of the valve element 6. The small coil spring 50 pushes the valve element 6 (the inner valve element 30 and the outer valve element 20) from the upstream side toward the downstream side.

[0048] The pressure reducing valve 2 further includes a piston 100 and a large coil spring 102. The piston 100 is configured to be able to move along Figure 1 The piston 100 is pressed toward the valve body 6 by the large coil spring 102. The piston 100 includes a protrusion 101 that protrudes toward the protrusion 36 of the inner valve body 30.

[0049] Next, the operation of the pressure reducing valve 2 described above will be described. First, it is assumed that the pressure reducing valve 2 is in a closed valve state. That is, it is assumed that the valve core 6 is in contact with the first valve seat portion 10 of the main body 4, and the first opening portion 12 is in a closed state. In addition, it is assumed that the inner valve core 30 is in contact with the outer valve core 20, and the second opening portion 24 is in a closed state. In the closed valve state of the pressure reducing valve 2, the pressure of the liquid in the second flow path 92 is maintained at a relatively high state.

[0050] (Valve opening action)

[0051] In the pressure reducing valve 2, the pressure of the liquid in the second flow path 92 is reduced by supplying the liquid to the supply destination of the liquid. Then, the piston 100 receiving the pressure of the liquid in the second flow path 92 is pushed toward the valve core 6 by the large coil spring 102, and the piston 100 moves toward the valve core 6. If the pressure of the liquid in the second flow path 92 is greatly reduced, the piston 100 moves greatly toward the valve core 6 accordingly. On the other hand, when the amount of reduction 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 core 6 is also small accordingly.

[0052] When the piston 100 moves toward the valve core 6, the protrusion 101 of the piston 100 contacts the protrusion 36 of the inner valve core 30 and pushes the inner valve core 30 toward the upstream side. As a result, the inner valve core 30 moves toward the upstream side. If the piston 100 moves greatly toward the valve core 6, the inner valve core 30 moves greatly toward the upstream side. On the other hand, when the amount of movement of the piston 100 toward the valve core 6 is small, the amount of movement of the inner valve core 30 toward the upstream side is also small.

[0053] When the inner valve core 30 moves to the upstream side, the second valve core portion 33 of the inner valve core 30 is separated from the second valve seat portion 27 of the outer valve core 20, and the second opening portion 24 becomes open. If the second opening portion 24 becomes open, the liquid flows out from the third flow path 93 on the inner side of the outer valve core 20 to the second flow path 92 via the second opening portion 24. This state is the first valve-opening state. The first valve-opening state is achieved 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 addition, in the first valve-opening state, the outer valve core 20 is pushed toward the downstream side under the action of the pressure of the liquid passing through the third flow path 93. As a result, the outer valve core 20 abuts against the first valve seat portion 10 of the main body 4.

[0054] When the inner valve core 30 moves further upstream from the first valve opening state, the second cylindrical portion 32 of the inner valve core 30 abuts against the first base end portion 23 of the outer valve core 20 and pushes the first base end portion 23 toward the upstream side. As a result, the outer valve core 20 moves toward the upstream side. When the outer valve core 20 moves toward the upstream side, the first valve core portion 26 of the outer valve core 20 separates from the first seat surface 14 of the first valve seat portion 10, and the first opening portion 12 becomes an open state. If the first opening portion 12 becomes an open state, the liquid flows out from the first flow path 91 to the second flow path 92 via the first opening portion 12. This state is the second valve opening state. The second valve opening state is achieved 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.

[0055] (Valve closing action)

[0056] Next, the valve closing action is described. The valve closing action is the opposite action to the above-mentioned valve opening action. In the above-mentioned pressure reducing valve 2, when the liquid flows into the second flow path 92, the pressure of the liquid in the second flow path 92 rises. Then, under the action of the pressure of the liquid in the second flow path 92, the piston 100 is pushed to the side opposite to the valve core 6, and the piston 100 moves to the side opposite to the valve core 6 (that is, the downstream side). If the piston 100 moves to the downstream side, the inner valve core 30 moves to the downstream side accordingly.

[0057] When the inner valve core 30 moves to the downstream side, the second valve core portion 33 of the inner valve core 30 abuts against the second valve seat portion 27 of the outer valve core 20, and the second opening portion 24 becomes closed. When the inner valve core 30 further moves to the downstream side, the outer valve core 20 is pushed to the downstream side by the inner valve core 30, and the inner valve core 30 and the outer valve core 20 move to the downstream side. When the inner valve core 30 and the outer valve core 20 move to the downstream side, the first valve core portion 26 of the outer valve core 20 abuts against the first valve seat portion 10 of the body 4, and the first opening portion 12 becomes closed.

[0058] (Effect)

[0059] The pressure reducing valve 2 of the embodiment has been described above. 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 portion 24 of the outer valve body 20; and the second cylindrical portion 32 that extends from the second valve body portion 33 in a cylindrical shape, and the second cylindrical portion 32 is arranged inside the first cylindrical portion 22 of the outer valve body 20. The second cylindrical portion 32 includes: the first end portion 80 that is located at the end portion on the second valve body portion 33 side; the second end portion 82 that is located at the end portion on the opposite side to the second valve body portion 33 (on the first base end portion 23 side of the outer valve body 20); and the middle portion 84 that is located between the first end portion 80 and the second end portion 82. The outer peripheral surface 62 of the middle portion 84 of the second cylindrical portion 32 is recessed inward in the radial direction of the second cylindrical portion 32 over the entire circumference of the circumference of the second cylindrical portion 32. The interval W84 between the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 is wider than the interval 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. In addition, the interval W84 between the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 is wider than the interval 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.

[0060] According to this structure, the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 of the inner valve core 30 is recessed inward, so that the liquid can be suppressed from stagnating between the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22. In addition, even if the interval between the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 and the inner peripheral surface 52 of the first cylindrical portion 22 is wide, the posture of the second cylindrical portion 32 can be stabilized inside the first cylindrical portion 22 due to the presence of the first end portion 80 and the second end portion 82 of the second cylindrical portion 32. According to the above, the posture of the inner valve core 30 can be stabilized and the liquid can be suppressed from stagnating between the inner peripheral surface 52 of the outer valve core 20 and the outer peripheral surface 62 of the inner valve core 30.

[0061] (Variation Example)

[0062] (1) The outer diameter at the first end 80 of the second cylindrical portion 32 of the inner valve core 30 may be smaller than the outer diameter at the second end 82 of the second cylindrical portion 32. That is, the interval 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 wider than the interval 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. According to this structure, it is possible to suppress the liquid from stagnating 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.

[0063] (2) In the above-mentioned embodiment, the outer peripheral surface 62 of the middle portion 84 of the second cylindrical portion 32 is formed into a curved surface, but the present invention is not limited to this structure. In a modified example, the outer peripheral surface 62 of the middle portion 84 of the second cylindrical portion 32 may be formed into a bent surface.

[0064] (3) In the above-mentioned embodiment, the valve core 6 includes the outer valve core 20, but the present invention is not limited to this structure. In a modified example, the valve core 6 may not include the outer valve core 20. In this case, Figure 7 As shown, an inner valve core 30 is arranged in the first flow path 91 of the main body 4. The inner valve core 30 is arranged to face the first opening portion 12 and the first seat surface 14 of the first valve seat portion 10 of the main body 4. The second valve core portion 33 of the inner valve core 30 opens and closes the first opening portion 12 by abutting or separating with respect to the first seat surface 14.

[0065] The outer peripheral surface 62 of the second cylindrical portion 32 of the inner valve core 30 is opposite to the inner peripheral surface 152 of the main body cylindrical portion 122 (another example of the outer cylindrical portion) of the main body 4 (another example of the outer member) in the radial direction of the second cylindrical portion 32. The interval between the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 of the inner valve core 30 and the inner peripheral surface 152 of the main body cylindrical portion 122 of the main body 4 is wider than the interval between the outer peripheral surface 62 at the first end portion 80 of the second cylindrical portion 32 and the inner peripheral surface 152 of the main body cylindrical portion 122. In addition, the interval between the outer peripheral surface 62 at the middle 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 interval between the outer peripheral surface 62 at the second end portion 82 of the second cylindrical portion 32 and the inner peripheral surface 152 of the main body cylindrical portion 122.

[0066] (4) In the above-mentioned embodiment, the pressure reducing valve 2 for reducing the pressure of the liquid is described, but the invention is not limited to this structure. In a modified example, the pressure reducing valve 2 for reducing the pressure of a gas (for example, hydrogen, etc.) may also be used. In this case, it is also possible to suppress the liquid (for example, water, etc.) mixed in the gas from being retained between the inner peripheral surface 52 of the outer valve core 20 and the outer peripheral surface 62 of the inner valve core 30.

[0067] (Test example)

[0068] A comparative test based on a test example and a comparative example is described. The pressure reducing valve of the test example is set as the pressure reducing valve 2 of the above-mentioned embodiment. Compared with the pressure reducing valve 2 of the embodiment, the pressure reducing valve of the comparative example is set as a structure in which the outer peripheral surface 62 at the middle part 84 of the second cylindrical part 32 of the inner valve core 30 is not recessed. For the test example and the comparative example, the amount of liquid retained in the gap 60 between the outer peripheral surface 62 at the middle part 84 of the second cylindrical part 32 of the inner valve core 30 and the inner peripheral surface 52 of the first cylindrical part 22 of the outer valve core 20 is compared by simulation.

[0069] Figure 8 The graph shown is a graph showing the results of a comparative test. Figure 8 The horizontal axis of the graph shown is the time for the liquid to flow in the gap 60. The vertical axis of the graph is the ratio of the volume of the liquid retained in the gap 60 facing the outer peripheral surface 62 at the middle portion 84 of the second cylindrical portion 32 to the volume of the first flow path 91 and the third flow path 93. Figure 8 As shown, it was confirmed that in the pressure reducing valve of the test example (pressure reducing valve 2 of the embodiment), the amount of liquid retained in the gap 60 of the outer peripheral surface 62 at the middle portion 84 facing the second cylindrical portion 32 was about 45% less than that of the pressure reducing valve of the comparative example. Based on the above, it was confirmed that according to the pressure reducing valve of the test example (pressure reducing valve 2 of the embodiment), it is possible to suppress the retention of liquid between the inner peripheral surface 52 of the outer valve element 20 and the outer peripheral surface 62 of the inner valve element 30.

[0070] The specific examples of the present invention are described in detail above, but these are only examples and do not limit the claims. The technology described in the claims includes various deformations and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings are technically useful alone or in various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the technology illustrated in this specification or the drawings can achieve multiple purposes at the same time, and achieving one of the purposes itself has technical usefulness.

[0071] Description of Reference Numerals

[0072] 2. Pressure reducing valve; 4. Main body; 6. Valve core; 10. Valve seat; 12. First opening; 14. Outer valve seat; 20. Outer valve core; 21. First top end; 22. First cylindrical portion; 23. First base end; 24. Second opening; 25. Third opening; 26. Outer valve core; 27. Inner valve seat; 30. Inner valve core; 31. Second top end; 32. Second cylindrical portion; 3 3. Inner valve core portion; 35. Spring chamber; 36. Protrusion; 50. Small coil spring; 52. Inner circumference; 60. Gap; 62. Outer circumference; 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; 102. Large coil spring; 122. Cylindrical portion; 152. Inner circumference.

Claims

1. A pressure reducing valve comprising an outer member and an inner member arranged inside the outer member, wherein: The outer member includes: a valve seat portion having an opening through which a fluid can pass; and an outer cylindrical portion extending from the valve seat portion in a cylindrical shape. The inner member includes: a valve core portion that opens and closes the opening; and an inner cylindrical portion that extends from the valve core portion in a cylindrical shape, the inner cylindrical portion being arranged inside the outer cylindrical portion. The inner cylindrical portion includes: a first end portion located at the end portion on the valve core portion side; a second end portion located at the end portion on the side opposite to the valve core portion; and an intermediate portion located between the first end portion and the second end portion. The outer peripheral surface of the middle portion of the inner cylindrical portion is recessed inward in the radial direction of the inner cylindrical portion over the entire circumference of the inner cylindrical portion. The interval between the outer circumferential surface at the middle portion of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion is wider than the interval between the outer circumferential surface at the first end portion of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion, and is wider than the interval between the outer circumferential surface at the second end portion of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion.

2. The pressure reducing valve according to claim 1, wherein: A distance between an outer circumferential surface at the first end of the inner cylindrical portion and an inner circumferential surface of the outer cylindrical portion is wider than a distance between an outer circumferential surface at the second end of the inner cylindrical portion and an inner circumferential surface of the outer cylindrical portion.

3. The pressure reducing valve according to claim 1, wherein: The interval between the outer circumferential surface of the first end of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion is the same as the interval between the outer circumferential surface of the second end of the inner cylindrical portion and the inner circumferential surface of the outer cylindrical portion.

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