Pressure regulating valve

Abstract

comprising pressure regulating valve (1): a pressure control chamber (21, 22); a piston (15) which is movable in an axial direction in response to pressure in the pressure control chamber (21, 22); a valve element (14) which is to be moved together with the piston (15); and a seat (12) with which the valve element (14) can be brought into contact, wherein the piston (15) includes a hollow piston section (43) in one end on a side closer to the seat (12), the hollow piston section opening on the side closer to the seat (12), and the valve element (14) has: a tip section (61) that can be brought into contact with the seat (12); a column-shaped section (52) which is inserted into the hollow piston section (43); and an insertion section (65) which projects radially outwards from an outer circumferential surface (52a) of the column-shaped section (52), wherein the insertion section (65) is inserted into an inner circumferential surface (43b) of the hollow piston section (43), and the insertion section (65) has a spherical shape, characterized by the fact that an outer diameter (d2) of the insertion section (65) is formed to be larger than an inner diameter (d1) of the hollow piston section (43).

Description

[0001] The present invention relates to a pressure control valve for regulating the pressure of a fluid, and in particular a pressure control valve for regulating the pressure of, for example, a high-pressure fuel gas by reducing the pressure to a desired pressure.

[0002] As one of pressure regulating valves for regulating the pressure of a fluid, the publication of the unexamined Japanese patent application (translation of the publication of the PCT application) No. 2010-533268 (“JP 2010-533268 A”) discloses a high-pressure regulator configured to bring a piston seat, which moves together with a piston, into contact with or away from a seat ring in order to regulate the pressure of a fluid.

[0003] German patent application DE 42 37 451 A1 discloses a hydraulic pressure reducing valve with the features of the preamble of claim 1.

[0004] In the high-pressure regulator disclosed in JP 2010-533268 A, the piston can slide within an internal bore of a body during displacement, for example, if it is tilted due to a coaxial misalignment of the piston relative to the internal bore (i.e., a deviation between their central axes). Furthermore, a coaxial misalignment between the seat ring and the piston seat can also be caused if the axis of an inlet pressure chamber formed within the seat ring and the axis of the piston are misaligned. This can result in a disturbance in the sealing force between the seat ring and the piston seat. During valve closure, when the seat ring is in contact with the piston seat, it is necessary to increase the pressure in an outlet pressure chamber if the tilt of the piston must be forcibly reduced to center (align) it between the seat ring and the piston seat.Thus, a pressure value (a pressure control value) in the outlet pressure chamber can increase during valve closure.

[0005] The following invention was made to solve the above problems and it has the objective of providing a pressure control valve that is able to prevent a pressure increase in a pressure control valve.

[0006] The problem is solved by the features of claim 1. Further developments of the present invention are specified in the dependent claims.

[0007] To solve the above problem, one aspect of the invention provides a pressure control valve comprising: a pressure control chamber; a piston that is movable in an axial direction in response to a pressure in the pressure control chamber; a valve element that is movable together with the piston; and a seat with which the valve element can be brought into contact, characterized in that the piston has a hollow piston section at one end on a side closer to the seat, the hollow piston section opening on the side closer to the seat, and the valve element comprising: a pointed section that can be brought into contact with the seat; a column-shaped section that is inserted into the hollow piston section;and an insertion section projecting radially outwards from an outer circumferential surface of the column-shaped section, wherein the insertion section is inserted into an inner circumferential surface of the hollow piston section, and the insertion section has a spherical shape.

[0008] As previously mentioned, the valve element can tilt relative to the piston while the insertion section of the column-shaped part of the valve element remains inserted into the hollow piston section. Therefore, even if the piston tilts or tilts, or if the seat and valve element are not coaxially aligned, the valve element simply needs to be brought into contact with the seat to center the valve element and secure it to the piston. Consequently, it is unnecessary to subsequently apply force to forcibly reduce the piston's tilt to center itself between the seat and the valve element during valve closure. This can suppress pressure rise in a pressure-regulating valve.

[0009] According to the pressure control valve configured as above, it is possible to suppress a pressure increase in a pressure control valve. Fig. Figure 1 is a cross-sectional view of a pressure regulating valve in one embodiment; Fig. Figure 2 is a side view of a valve element; Fig. Figure 3 is a cross-sectional view of the valve element and a recessed section of a piston, showing that the valve element has not yet been pressed into the recessed section of the piston; Fig. Figure 4 is a cross-sectional view of the seat, the valve element, and the recessed section of the piston, showing that the valve element is in the process of being pressed into the recessed section of the piston; and Fig. Figure 5 is a cross-sectional view of the seat, the valve element and the recessed section of the piston, showing that the valve element is fully pressed into the recessed section of the piston.

[0010] A detailed description of a preferred embodiment of a pressure regulating valve embodying the present invention is now given with reference to Fig. 1 to Fig. 5. In this embodiment, the invention is applied to a pressure reducing valve for reducing the pressure of a high-pressure fuel gas to be supplied to a delivery point. In the following description, the terms "upstream side" and "downstream side" each denote an upstream side or position and a downstream side or position in a flow direction of the fuel gas G.

[0011] A pressure regulating valve 1 is a pressure reducing valve for regulating the pressure of the fuel gas G by reducing its pressure to a desired level. In the present embodiment, the fuel gas G is, for example, hydrogen gas to be supplied to a vehicle fuel cell or a battery (not shown). An upstream end of the pressure regulating valve 1 is connected to a main stop valve (not shown) to enable or stop the supply of the fuel gas G stored in a fuel tank (not shown). A downstream end of the pressure regulating valve 1 is connected to an injection device (not shown) for supplying the fuel gas G to a fuel cell or a battery.

[0012] As in Fig. As shown in Figure 1, the pressure regulating valve 1 comprises a housing 10, a seat (a valve seat) 12, a valve element 14, a piston 15, a spring 16, and other components. The housing 10 is primarily formed from an inlet block element 11, a body element 13, and an outlet block element 17. The body element 13 forms an internal first pressure regulating chamber 21. Furthermore, a second pressure regulating chamber 22 is delimited by the body element 13, the piston 15, and the outlet block element 17. Fig. Figure 1 shows the pressure regulating valve 1 during a valve closing, in which the valve element 14 is in contact with the seat 12.

[0013] The inlet block element 11 is provided with an inlet 31, an inlet passage 32, and other components. The inlet 31 is an inlet opening through which the fuel gas G flows into the pressure regulating valve 1. The inlet passage 32 is a passage connected to the inlet 31 and a seat hole (through hole) 33 of the seat 12. A filter 34 is located in the inlet passage 32 to allow the fuel gas G to pass through while removing any foreign matter contained in the fuel gas G. Furthermore, a bushing 35 is located between the filter 34 and the seat 12.

[0014] The seat 12 is made of resin and, compressed to a predetermined extent, is wedged between the inlet block element 11 and the body element 13. The seat 12 has an approximately circular ring shape. This seat 12 is provided with the seat hole 33, which is connected to the inlet passage 32 and the first pressure control chamber 21.

[0015] The body element 13 is a casing for the pressure regulating valve 1 and accommodates the valve element 14, the piston 15, the spring 16 and part of the outlet block element 17.

[0016] The valve element 14 is located in the first pressure control chamber 21, which is situated downstream of the seat 12. Within the first pressure control chamber 21, the valve element 14 moves together with the piston 15 to engage with or disengage from the seat 12, thereby blocking or allowing the flow of the fuel gas G. Specifically, the valve element 14 serves to open and close a flow channel connecting the seat hole 33 of the seat 12 and the first pressure control chamber 21. This valve element 14 is made of metal.

[0017] As in Fig. As shown in 2, the valve element 14 contains in an order from one side closer to the seat 12 (i.e. from a top side in Fig. 2), a sealing part 51 which can be brought into contact with the seat 12, and a retaining part 52 (a column-shaped part) which is received and held in a cup-shaped, recessed section 43 of the piston 15. The retaining part 52 is located on a side or in a position closer to the piston 15 than the sealing part 51.

[0018] The sealing part 51 is provided with a pointed section 61, a cylindrical section 62, a large diameter section 63 and further parts, arranged in a sequence from a side closer to the seat 12.

[0019] The tip section 61 is a part that can come into contact (seat) with the seat 12 and has a spherical shape, more precisely a hemispherical or dome-shaped form. Thus, the tip section 61 of the valve element 14 can be reliably brought into close line contact with the entire circumference of the seat hole 33 of the seat 12. This tip section 61 can be brought into contact with the seat 12 to close the seat hole 33 during valve closure. The cylindrical section 62 has a continuous circular cylindrical shape that extends to the tip section 61 and the large-diameter section 63. The large-diameter section 63 has an outer diameter that is larger than the outer diameter of both the tip section 61 and the cylindrical section 62. The large diameter section 63 is provided with an end face 64 located on a side closer to the piston 15 (i.e.h. on a side that continues to the retaining part 52).

[0020] The retaining part 52 has an approximately column-like shape. This retaining part 52 has an outer diameter that is smaller than the outer diameter of the end face 64 of the large-diameter section 63 of the sealing part 51. The retaining part 52 is provided with a press-fit section 65 (an insertion section).

[0021] This press-fit section 65 projects radially outwards from an outer circumferential surface 52a of the retaining part 52. Specifically, the outer diameter d2 of the press-fit section 65 is larger than the outer diameter of a remaining section of the outer circumferential surface 52a of the retaining part 52, which is different from the press-fit section 65. Furthermore, the outer diameter d2 of the press-fit section 65 is larger than the inner diameter d1 (see Fig. 3) of the recessed section 43 of the piston 15, which will be described later. Accordingly, the press-fit section 65 is pressed (inserted) into an inner circumferential surface 43b of the recessed section 43 of the piston 15 (see Fig. 5) The press-fit section 65 is formed on the retaining part 52 in its entire circumferential direction.

[0022] In the present embodiment, the press-fit section 65 of the valve element 14 has a spherical shape, more precisely a spherical section shape, which is designed with a diameter equal to the outer diameter d2. In particular, the outer circumferential surface of the press-fit section 65 is a spherical zone or a curved surface. As in Fig. As shown in Figure 2, the press-fit section 65 is located in an axial direction (an up and down direction in Fig. 2) at a position above the center of the retaining part 52 of the valve element 14, i.e. in the axial direction at an approximately central position of the entire valve element 14.

[0023] The retaining part 52 has a contact end section 66, which is designed to be inserted into the piston 15. This contact end section 66 will come into contact with a base surface 43a of the piston 15 during valve closing (see Fig. 5) In the present embodiment, the contact end section 66 also has a spherical shape, more precisely, a partially spherical shape, which is a section of a sphere, as shown in Fig. As specified in Figure 2, the contact end section 66 has a diameter D. This means that the outer surface of the contact end section 66 is a partially spherical or rounded surface. Instead of the previously mentioned spherical contact end section 66 of the valve element 14, the bottom surface 43a of the recessed section 43 of the piston 15 can be spherical (a rounded surface projecting towards the opening 43e). The diameter D is chosen to be larger than the outer diameter d2.

[0024] The piston 15 is in response to the pressure in the second pressure control chamber 22 in an axial direction (in an up-down direction). Fig. 1) movable within the housing 10. As in Fig. As shown in Figure 1, the piston 15 is provided with a body section 36, a shaft section 37, a passage 38, the recessed section 43, and other components. The body section 36 has a cylindrical shape and is located downstream of the shaft section 37. On the side of the body section 36 closer to a spring 16, it has a spring seat 39 (a contact section with the spring 16) against which one end of the spring 16 abuts. A seal 41, which acts as a sealing element, is positioned on the outer circumferential surface of the body section 36.

[0025] The shaft section 37 has a cylindrical shape and is positioned upstream of the body section 36. The shaft section 37 is provided with inlet openings 42, which provide communication between the passage 38 and the first pressure control chamber 21. The passage 38 is shaped to extend in an axial direction along the piston 15.

[0026] The shaft section 37 is connected at one end on the upstream side (i.e., on a side closer to the seat 12) to the recessed section 43 (a hollow piston section) formed by drilling or another technique in a recessed shape (a U-shaped cross-section or a cup-like shape) that opens on the side closer to the seat 12, i.e., on a surface facing the seat 12. A portion of the valve element 14 is inserted into this recessed section 43. In the present embodiment, as shown in Fig. 3 to Fig. As shown in Figure 5, the recessed section 43 has an end section 43c formed with an opening 43e that opens on the side closer to the seat 12, and furthermore, in the end section 43c, a conical section 43d having an inner diameter that decreases from the opening 43e towards the interior of the recessed section 43, i.e., towards the bottom surface 43a. The recessed section 43 also includes the inner circumferential surface 43b, which has an inner diameter d1 in a section closer to the bottom surface 43a than the conical section 43d.

[0027] As in Fig. As shown in Figure 1, a seal 44 (a sealing element) and a thrust ring 45 (a bearing) are mounted on the outer circumferential surface of the shaft section 37. The piston 15 is made of metal.

[0028] The spring 16 is positioned between the body element 13 and the piston 15. This spring 16 pushes the piston 15 in a direction towards the exhaust block element 17, i.e., in a valve-opening direction of the valve element 14.

[0029] The outlet block element 17 is provided with a passage 71 which is connected to an outflow opening (not shown) through which the fuel gas G flows out of the pressure regulating valve 1.

[0030] The first pressure control chamber 21 is located downstream of the seat 12 in the housing 10. When the valve element 14 separates from the seat 12, the first pressure control chamber 21 comes into contact with the inlet 31 of the inlet block element 11. The second pressure control chamber 22 is located downstream of the piston 15. This second pressure control chamber 22 is delimited in the housing 10 by the body element 13, the piston 15, and the outlet block element 17. The pressure of the fuel gas G is regulated in this first pressure control chamber 21 and this second pressure control chamber 22.

[0031] The operations (an operating procedure) of the pressure control valve 1 in the present embodiment are described below. For example, the pressure of the fuel gas G stored in the second pressure control chamber 22 decreases when the fuel gas G begins to be supplied to a vehicle fuel cell, and in a direction that is Fig. The flow is indicated by an arrow at point 1, through passage 71. Accordingly, the piston 15 is moved towards the outlet block element 17 by the pushing force of the spring 16.

[0032] As the valve element 14 separates from the seat 12, a high-pressure fuel gas G supplied from a fuel tank is allowed to flow through the inlet 31, the inlet passage 32, and the seat hole 33 of the seat 12, and then into the first pressure control chamber 21. Furthermore, the fuel gas G flowing into the first pressure control chamber 21 continues to flow through the inlet openings 42 of the piston 15 and the passage 38 into the second pressure control chamber 22.

[0033] Accordingly, the pressure of the fuel gas in the second pressure control chamber 22 increases. When the force exerted on the piston 15 by the pressure of the fuel gas becomes greater than the pushing force of the spring 16, the piston 15 is moved against the pushing force of the spring 16 towards the seat 12. In conjunction with this movement of the piston 15, the valve element 14 is caused to come into contact with the seat 12, thereby stopping the flow of fuel gas G into the first pressure control chamber 21 and the second pressure control chamber 22. In this way, the pressure of the fuel gas G in each of the first pressure control chamber 21 and the second pressure control chamber 22 is maintained at a predetermined value.To be precise, the pressure in the first pressure control chamber 21 and the second pressure control chamber 22 is regulated such that the force obtained by multiplying the area (the cross-sectional area) of a diameter of the second pressure control chamber 22, which is sealed by the seal 41, with the pressure in the second pressure control chamber 22 is equal to the pushing force of the spring 16.

[0034] Here, the piston 15 is displaced while being held in contact with a wall surface 13a of the body element 13 by the thrust ring 45. At this point, if, for example, the piston 15 has a coaxial misalignment (deviation of the central axis) with respect to the cylindrical wall surface 13a that defines the first pressure control chamber 21 in which the piston 15 slides, or if the thrust ring 45 has a thickness that varies or is uneven from section to section, the piston 15 may slide in a tilted or inclined position. Furthermore, if the inlet block element 11 and the seat hole 33 of the seat 12 held in the inlet block element 11 are not coaxially aligned, this may cause a coaxial misalignment between the valve element 14 held by the piston 15 and the seat 12.If the aforementioned tilting or inclination of the piston 15 and a coaxial misalignment between the seat 12 and the valve element 14 occur, a portion of the valve element 14 may fail to make tight contact with the seat 12 during valve closing, when the valve element 14 must be in contact with the seat 12. This results in a disrupted sealing force between the seat 12 and the valve element 14. If force must be applied to the piston 15 to forcibly reduce its inclination and center (align) it between the seat 12 and the valve element 14, it is necessary to increase the fuel gas pressure G in the second pressure control chamber 22 during such valve closing. Therefore, the fuel gas pressure G (hereinafter referred to as the "pressure control value") in the second pressure control chamber 22 may increase during valve closing.

[0035] In the present embodiment, the valve element 14 is therefore assembled into the recessed section 43 of the piston 15 during the manufacturing of the pressure regulating valve 1 during a performance measurement (e.g., in a gas tightness test of the pressure regulating valve 1). During this manufacturing process, centering between the seat 12 and the valve element 14 and securing the valve element 14 to the piston 15 are completed in advance.

[0036] To be precise, at the time of the performance measurement in the manufacturing process of pressure regulating valve 1, as in Fig. As shown in Figure 3, the valve element 14 is first inserted into the recessed section 43 of the piston 15. The fuel gas G is then supplied to flow through the inlet 31 into the second pressure control chamber 22, thereby increasing the pressure in the second pressure control chamber 22 and moving the piston 15 towards the seat 12 so that the tip section 61 of the valve element 14 comes into contact with the seat 12. Thus, the valve element 14 is pressed through the seat 12 into the recessed section 43 of the piston 15. Finally, as the press-fit section 65 is pressed into the inner circumferential surface 43b of the recessed section 43, the valve element 14 is attached to the piston 15.

[0037] In the present embodiment, the press-fit section 65 of the valve element 14 has, as shown in Fig. Figure 2 shows the spherical shape. Accordingly, the valve element 14 can be inclined relative to the piston 15 about a contact section, as a bearing point, of the press-fit section 65 with the inner circumferential surface 43b of the recessed section 43, while the press-fit section 65 remains pressed into the inner circumferential surface 43b of the recessed section 43 of the piston 15. Therefore, even in the case where the inclination of the piston 15 and the coaxial misalignment between the seat 12 and the valve element 14 have occurred, the valve element 14 can be inclined relative to the piston 15 when the piston 15 is moved in the direction towards the seat 12 to bring the tip section 61 of the valve element 14 into contact with the seat 12.Thus, the valve element 14 can be pressed into the recessed section 43 of the piston 15 by itself, while the coaxial misalignment is absorbed by the seat 12 independently, and centering is carried out with the seat 12.

[0038] In the present embodiment, the contact end section 66 of the valve element 14, as shown in Fig.Figure 2 shows the spherical shape. Accordingly, even if the contact end section 66 comes into contact with the bottom surface 43a of the recessed section 43 during the pressing of the valve element 14 into the recessed section 43 of the piston 15, the valve element 14 can be inclined relative to the piston 15 about the bearing point defined by the contact section of the contact end section 66 with the bottom surface 43a of the recessed section 43. Furthermore, when the contact end section 66 comes into contact with the bottom surface 43a of the recessed section 43, the valve element 14 is no longer pressed towards the piston 15. The valve element 14 is inclined relative to the piston at the time when the tip section 61 of the valve element 14 comes into contact with the seat 12, so that the valve element 14 is pressed into the recessed section 43 of the piston 15 by itself, while centering with the seat 12 is carried out.Thus, the valve element 14 is attached to the piston 15.

[0039] In the present embodiment, the seat 12 and the valve element 14 can be pre-aligned for centering during the manufacturing of the pressure control valve 1, and the valve element 14 can also be pre-pressed and secured in the recessed section 43 of the piston 15. In other words, during the manufacturing of the pressure control valve 1, the pressure in the second pressure control chamber 22 is increased to facilitate the completion of centering between the seat 12 and the valve element 14 and securing the valve element 14 to the piston 15. Therefore, it is not necessary to forcefully apply the force required to reduce the inclination of the piston 15 for centering between the seat 12 and the valve element 14 during valve closure when the pressure control valve 1 is subsequently used (i.e., after the pressure control valve 1 has been manufactured).Therefore, the pressure of the fuel gas G in the second pressure regulating chamber 22 does not need to be increased. Consequently, in the present embodiment, the pressure regulating valve 1 can suppress a pressure increase in a pressure adjusting valve.

[0040] It is preferred that the valve element 14 is pressed into and secured in the recessed section 43 of the piston 15 with a gap or space between a section of the outer circumferential surface 52a of the retaining part 52 of the valve element 14, excluding the press-fit section 65, and the inner circumferential surface 43b of the recessed section 43 of the piston 15, and between the end surface 64 of the sealing part 51 of the valve element 14 and the end section 43c of the recessed section 43 of the piston 15. Accordingly, when the valve element 14 is to be pressed into the recessed section 43 of the piston 15, the valve element 14 can be inclined with respect to the piston 15 without being restricted by the inner circumferential surface 43b and the end section 43c of the recessed section 43. This makes it easy to align the seat 12 and the valve element 14 for centering.The press-in section 65 is formed in a zone of the valve element 14 which, after being pressed into the recessed section 43 of the piston 15, does not correspond to the position of the conical section 43d of the recessed section 43 of the piston 15.

[0041] The piston 15 is provided, on the side of the opening 43e of the recessed section 43 in the end section 43c, with a conical section 43d, which has an inner diameter that decreases from the opening 43e towards the interior of the recessed section 43. Accordingly, the valve element 14 can move along the surface of the conical section 43d of the recessed section 43 when the valve element 14 is to be pressed into and secured in the piston 15. Thus, the valve element 14 can be easily pressed into the inner circumferential surface 43b of the recessed section 43.

[0042] The preceding embodiments are merely examples and do not constitute a limitation of the present invention. The present invention can be implemented in other specific forms without deviating from its essential features. For example, the press-fit section 65 of the valve element 14 can be partially cut out in one circumferential direction of the retaining part 52, i.e., the press-fit section 65 need not extend continuously over the entire circumference of the retaining part 52. LIST OF REFERENCE SIGNS 1 pressure regulating valve 2 seats 13a Wall area 14 Valve seat 15 pistons 21 first pressure control chamber 22 second pressure control chamber 31 Admission 33 Seat Hole 43 in-depth section 43a Floor area 43b inner circumferential surface 43d conical section 43e Opening 45 Thrust ring 52 Holding part 52a outer circumferential surface 61 Top section 65 Press-fit section 66 Contact end section G Fuel gas d1 inner diameter (of recessed section) d2 outer diameter (of press-fit section)

Claims

[1] comprising pressure regulating valve (1): a pressure control chamber (21, 22); a piston (15) which is movable in an axial direction in response to pressure in the pressure control chamber (21, 22); a valve element (14) which is to be moved together with the piston (15); and a seat (12) with which the valve element (14) can be brought into contact, wherein the piston (15) includes a hollow piston section (43) in one end on a side closer to the seat (12), the hollow piston section opening on the side closer to the seat (12), and the valve element (14) has: a tip section (61) that can be brought into contact with the seat (12); a column-shaped section (52) which is inserted into the hollow piston section (43); and an insertion section (65) which projects radially outwards from an outer circumferential surface (52a) of the column-shaped section (52), wherein the insertion section (65) is inserted into an inner circumferential surface (43b) of the hollow piston section (43), and the insertion section (65) has a spherical shape, characterized by , that an outer diameter (d2) of the insertion section (65) is formed to be larger than an inner diameter (d1) of the hollow piston section (43). [2] Pressure regulating valve (1) according to claim 1, wherein the hollow piston section (43) has a recessed shape that opens on the side closer to the seat (12), the column-shaped section (52) of the valve element (14) is provided with a contact end section (66) which will come into contact with a bottom surface (43a) of the recessed hollow piston section (43), and the contact end section (66) has a spherical shape. [3] Pressure regulating valve (1) according to claim 1 or 2, wherein the hollow piston section (43) comprises an end section (43c) formed with an opening (43e) that opens on the side closer to the seat (12) and, in the end section (43e), includes a conical section (43d) having an inner diameter that decreases from the opening (43e) to the interior of the hollow piston section (43).

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