Seal structure

Abstract

The present invention provides a sealing structure for a valve of the type in which a valve body is formed at a front end of a valve stem, and the valve is closed or opened by moving the valve stem in a central axis direction, in which an annular sealing material is arranged in a multi-stage continuous manner to form a multi-stage seal in a region in which the valve stem slides. The sealing structure of the present invention is characterized by comprising a plurality of stages of combinations consisting of: a C-shaped member having a circular ring, a portion of which is cut out in the circumferential direction of the circular ring; a composite member including a hollow cylindrical portion and a flange extending radially outward in a central axis direction of the hollow cylindrical portion on a valve body side of the hollow cylindrical portion, the hollow cylindrical portion being inserted into a central hollow portion of the C-shaped member; and a support ring and an O-ring disposed on the flange of the composite component.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202511368602.7 (22) Application Date 2025.09.24 (30) Priority Data 2024-165829 2024.09.25 JP (71) Applicant: Tatsuno Co., Ltd. Address: Japan (72) Inventor: Masahiro Takezawa (74) Patent Agency: Beijing Zhongzi Law Firm 11247 Patent Attorney: Lirong Ma, Peng Wu (51) Int.Cl. F16K 41 / 02 (2006.01) (54) Title of Invention: Sealing Structure (57) Abstract: This invention provides a sealing structure for a valve of the type in which a valve body is formed at the front end of a valve stem and the valve is closed or opened by moving the valve stem along a central axis, wherein annular sealing material is arranged in a multi-stage continuous manner in the region where the valve stem slides to form a multi-stage seal. The sealing structure of the invention is characterized by comprising a multi-stage combination of the following: a C-shaped member having an annulus, a portion of which is cut off circumferentially; a composite member comprising a hollow cylindrical portion and a flange extending radially outward along the central axis of the hollow cylindrical portion on the valve body side of the hollow cylindrical portion, the hollow cylindrical portion being inserted into the central hollow portion of the C-shaped member; and a support ring and an O-ring disposed on the flange of the composite member. Claims 1 page, Description 10 pages, Drawings 14 pages, CN 121739182 A 2026.03.27 CN 1 21 73 91 82 A 1. A sealing structure comprising a multi-stage combination of the following: a C-shaped member having an annulus, a portion of which is cut off along the circumferential direction of the annulus; a composite member comprising a hollow cylindrical portion and a flange extending radially outward along the central axis of the hollow cylindrical portion on the valve body side of the hollow cylindrical portion, the hollow cylindrical portion being inserted into the central hollow portion of the C-shaped member; and a support ring and an O-ring disposed on the flange of the composite member. 2. A shut-off valve, comprising: a housing having a fluid flow passage formed along a central axis; a valve stem disposed in the flow passage and extending along the central axis; a valve body formed at a front end of the valve stem; a valve seat formed in the housing near one end of the flow passage; and a valve closing mechanism for pressing the valve body against the valve seat, the valve closing mechanism comprising an actuator and a valve closing force adjusting mechanism, wherein the valve closing force adjusting mechanism is disposed in a pressure transmission chamber receiving the valve stem at the end opposite to the valve body; and a valve stem actuation shaft.It engages with the valve stem and is moved along the central axis direction by the actuator; and a pressure regulating spring, which is interposed between the actuator and the valve stem actuation shaft to regulate the compressive force of the valve stem actuation shaft, and the sealing structure as claimed in claim 1 is installed in the flow passage through which the valve stem actuation shaft extends to prevent fluid from flowing into the actuator side. 3. A flow regulating valve, comprising: a cam plate having an inclined surface formed on its surface; a drive source for rotating the cam plate via a reduction mechanism; a cam follower having one of a rotating portion and a moving portion, the latter pressing against the surface of the cam plate and moving along the central axis direction of the flow regulating valve in response to the inclination of the surface of the cam plate; and a valve stem support, one end of which is connected to the cam follower and the other end of which is connected to the valve stem, wherein the flow rate varies according to the size of the small diameter portion into which the valve stem is inserted in the flow passage, and the sealing structure as claimed in claim 1 is installed in the region where the valve stem, extending along the central axis direction of the housing, slides. Claims 1 / 1 page 2 CN 121739182 A Sealing Structure Technical Field

[0001] This invention relates to a sealing structure used in shut-off valves or flow control valves for high-pressure fluids such as high-pressure hydrogen. Background Art

[0002] In shut-off valves and flow control valves for high-pressure fluids such as high-pressure gases, the valve body is located at the front / end of the valve stem. By moving the valve stem along the central axis, the valve body can be positioned on a valve seat formed within the flow passage to close the valve, or the valve body can be moved away from the valve seat to open the valve. In these types of valves, the valve stem is sealed with a cup seal or an O-ring to prevent leakage of the working fluid from the sliding part of the valve stem (the movable part of the valve stem).

[0003] To seal the valve stem, seamless annular sealing materials, such as O-rings or support rings, are required. However, it is difficult to install such annular sealing materials or support rings in the area where the valve stem slides, and there is a problem that the sealing material cannot be continuously arranged in multiple stages to form a multi-stage seal.

[0004] As another prior art, JP6972506B proposes a shut-off valve that improves the sliding performance, sealing performance, and durability of the sliding portion. Although this prior art is useful, it does not solve the aforementioned problems.

[0005] The contents of JP6972506B are incorporated herein by reference in their entirety. Summary of the Invention

[0006] The present invention was made in view of the problems of the prior art described above, and its object is to provide a sealing structure for a valve of the type in which the valve body is disposed at the front / end of the valve stem and the valve is closed or opened by moving the valve stem along the central axis, wherein, in the region where the valve stem slides, annular sealing material is arranged in a multi-stage continuous manner to form a multi-stage seal.

[0007] [Means for Solving the Problem]

[0008] The sealing structure 30 of the present invention is characterized by comprising a multi-stage combination of the following: a C-shaped member (C-ring) 32 having an annulus, a portion of which is cut off in the circumferential direction; a composite member 33 comprising a hollow cylindrical portion 33A and a flange 33B extending radially outward along the central axis of the hollow cylindrical portion 33A on the valve body side of the hollow cylindrical portion 33A, the hollow cylindrical portion 33A being inserted into the central hollow portion of the C-shaped member 32; and a support ring 34 and an O-ring 35 disposed on the flange 33B of the composite member 33.

[0009] The shut-off valve 100 comprises: a housing 2 having a fluid flow passage 3 formed along the central axis; a valve stem 1 disposed in the flow passage 3 and extending along the central axis; a valve body 1AT formed at the front end of the valve stem 1; and a valve seat 3AT. It is formed in the housing 2 near the end of the flow passage 3; and a valve closing mechanism 10 for pressing the valve body 1AT against the valve seat 3AT, the valve closing mechanism 10 consisting of an actuator 11 and a valve closing force adjusting mechanism 50A, wherein the valve closing force adjusting mechanism 50A has a valve stem actuation shaft 40 in the pressure transmission chamber 5 that accommodates the end of the valve stem 1 opposite to the valve body 1AT, the valve stem actuation shaft 40 engaging with the valve stem 1 and moving along the central axis direction through the actuator 11, and a pressure adjusting spring 144 interposed between the actuator 11 and the valve stem actuation shaft 40 to adjust the pressing force of the valve stem actuation shaft 40, and a sealing structure 30 preferably installed in the flow passage through which the valve stem actuation shaft 40 extends to prevent fluid from flowing into the actuator 11 side.

[0010] The flow regulating valve 200 includes: a cam plate 41 having an inclined surface formed on its surface 41A; a drive source 50 for rotating the cam plate 41 via a speed reduction mechanism 51; a cam follower 42 having one of a rotating portion 42A and a moving portion, the latter pressing against the surface 41A of the cam plate 41 and moving along the central axis of the flow regulating valve 200 in response to the inclination of the surface 41A of the cam plate 41; and a valve stem support 43, one end of which is connected to the cam follower 42 and the other end of which is connected to the valve stem 1-1, wherein the flow rate varies according to the size Lt of the small diameter portion into which the valve stem 1-1 is inserted into the flow passage 3, and a sealing structure 30 is preferably installed in the region where the valve stem 1-1 slides along the central axis of the housing 2-1.

[0011] Effects of the Invention

[0012] In the sealing structure 30 of the present invention having the above-described configuration, in the hollow portion 31 in which the valve stem 1 slides and in which a plurality of grooves 31A are intermittently formed, the intermittently formed grooves 31A have a large inner diameter so as to accommodate the C-shaped member 32. The hollow cylindrical portion 33A of the composite member 33 having a hollow cylindrical portion 33A and a flange 33B is inserted into the C-shaped member.In the hollow portion 32A of component 32, a support ring 34 and an O-ring 35 are placed on the flange 33B. Thus, the O-ring 35, the support ring 34, the component 33 having the hollow cylindrical portion 33A and the flange 33B, and the C-shaped component 32 are combined to form a sealing unit (C32-35). Since the integral seal (C32-C35) can be arranged in the grooves 31A formed intermittently in the hollow portion 31, the present invention can form a multi-layer sealing structure with multiple layers continuously stacked along the central axis direction of the portion of the valve stem 1 that slides therein. Therefore, it is possible to easily and reliably form a multi-stage sealing structure in the sliding portion of the valve stem that is difficult to achieve with the prior art.

[0013] According to the present invention, a sealing structure can be provided for a valve, wherein the valve body is disposed at the front end of the valve stem, and the valve is closed or opened by moving the valve stem along the central axis direction, and wherein annular sealing material is arranged in a multi-stage continuous manner in the area in which the valve stem slides therein to form a multi-stage seal.

[0014] Figure 1 shows a cross-sectional view of a conventional sealing structure.

[0015] Figure 2 shows a cross-sectional view of a sealing structure according to an embodiment of the present invention.

[0016] Figure 3 is a perspective view of the hollow cylindrical-flange composite member used in the sealing structure of Figure 2.

[0017] Figure 4 is a perspective view of the C-ring used in the sealing structure of Figure 2.

[0018] Figure 5 shows a cross-sectional view of a shut-off valve equipped with a sealing structure according to the illustrated embodiment in its open state.

[0019] Figure 6 is a partially enlarged cross-sectional view of part A in Figure 5.

[0020] Figure 7 shows a cross-sectional view of the shut-off valve shown in Figure 5 immediately after it is closed.

[0021] Figure 8 shows a cross-sectional view of the valve after a predetermined time has elapsed since the shut-off valve shown in Figure 5 was closed.

[0022] Figure 9 shows a cross-sectional view of a flow regulating valve provided with a sealing structure according to the illustrated embodiment.

[0023] [Fig. 10] shows a cross-sectional view of the flow control valve of Fig. 9 taken along a cross section perpendicular to the cross section of Fig. 9.

[0024] [Fig. 11] shows an enlarged cross-sectional view of the relative position of the shaft front end and the small-diameter flow passage portion in the flow control valves shown in Figs. 9 and 10 in a low flow rate region.

[0025] [Fig. 12] Perspective view of the flow control valves shown in Figs. 9 and 10.

[0026] [Fig. 13] shows a perspective view of the configuration of Fig. 12, wherein the housing is omitted.

[0027] [Fig. 14] shows a perspective view of the cam plate, cam follower, and valve stem support.

[0028] [Fig. 15] View taken along arrow A15 in Fig. 14.

[0029] [Fig. 16] shows a perspective view of the cam plate. Specification 2 / 10 pages 4 CN 121739182 A Detailed Description

[0030] Hereinafter, an embodiment of the invention will be described with reference to the accompanying drawings. First, the sealing structure 30 according to the illustrated embodiment will be described with reference to Figures 2 to 4. This sealing structure 30 can be used, for example, in the shut-off valve 100 described later with reference to Figures 5 to 8 and the flow regulating valve 200 described later with reference to Figures 9 to 16. As will be described later, in the shut-off valve 100 of Figures 5 to 8 and the flow regulating valve 200 of Figures 9 to 16, valve bodies 1AT and 1AT-1 are disposed at the front ends of valve stems 1 and 1-1, and the shut-off valve 100 and the flow regulating valve 200 are opened and closed by movement of valve stems 1 and 1-1 along their central axis. The sealing structure 30 shown in Figures 2 to 4 is disposed at a position where the valve stems 1 and 1-1 slide within the housings 2 and 2-1 during movement.

[0031] Similarly, in the prior art, in order to prevent fluid (e.g., high-pressure hydrogen) from leaking from the sliding point of the valve stem 1 (1-1) in the flow passage 3 of the housing (as shown by arrow A1), as shown in FIG1, sealing materials such as O-rings 35 are arranged at the sliding point. In order to prevent high-pressure hydrogen from leaking from the sliding point of the valve stem 1, a multi-stage seal with multiple O-rings 35 is required. In a shut-off valve or flow control valve, multiple grooves 31A (expanded diameter portions) can be intermittently formed along the central axis direction at the sliding point 31 (hole, hollow portion) of the valve stem 1 to cooperate with the O-rings 35 as sealing materials. In order to prevent the phenomenon of the O-rings 35 biting into the gap of the groove portion 31A formed in the sliding portion 31 of the valve stem 1 due to high pressure, i.e., the so-called "O-ring protrusion", and to obtain good pressure resistance, the O-rings 35 are used in combination with an annular support ring 34.

[0032] In the prior art shown in FIG1, in order to accommodate the O-ring 35 in the groove portion (expanded diameter portion) 31A provided in the valve stem sliding portion (hollow portion) 31 and combine it with the support ring 34 to form a multi-stage structure, the inner diameter of the valve stem sliding portion 31 must be the same as the inner diameter D of the groove portion 31A that accommodates the O-ring 35. When the groove portion 31A is not formed discontinuously along the central axis direction, it is impossible to combine the O-ring 35 with the support ring 34 to form a multi-stage structure.

[0033] In contrast, as shown in FIG2, in the sealing structure 30 according to the illustrated embodiment, the combination of the O-ring 35, support ring 34, hollow cylindrical body-flange composite member 33, and C-ring 32 is stacked in multiple stages along the central axis direction of the hollow portion 31. In FIG2, a flow passage 3 for working fluid is formed along the central axis direction of the housing (not shown), through which the valve stem 1 and the like extend. In the flow passage 3, in the hollow portion 31 for sliding of the valve stem 1, multiple regions (expanded diameter portions) 31A with larger inner diameters are formed intermittently at equal intervals along the central axis direction (two locations are shown in the example of Figure 2). The sealing structure 30 in Figure 2 is provided, for example, in the region where the valve stem actuation shaft 13 slides along the central axis direction in the hollow portion of the shut-off valve 100 (Figures 5, 7 and 8).

[0034] When the sealing structure 30 is installed in the hollow portion 31 for sliding of the valve stem actuation shaft 13 (valve stem 1, etc.), a C-ring 32 is arranged and fitted in the expanded diameter portion 31A of the hollow portion 31, and the C-ring 32 has a shape in which a portion of the annular ring is cut off in the circumferential direction. A hollow cylindrical / flange composite member 33 is placed above the C-ring 32. When the hollow cylindrical / flange composite member 33 is placed, a hollow cylindrical region 33A extending along the central axis direction (vertical direction) of the hollow cylindrical / flange composite member 33 is inserted into the hollow portion 32A formed in the radial center of the C-ring 32. The support ring 34, O-ring 35 and support ring 34 are placed sequentially on the flange 33B of the hollow cylindrical / flange composite member 33. That is, two support rings 34 are placed on the flange 33B of the hollow cylindrical / flange composite member 33, with an O-ring 35 sandwiched between them. In adjacent combinations (combinations of O-ring 35, support ring 34, hollow cylindrical / flange composite member 33, and C-ring 32), the C-ring 32 is positioned above the support ring 34, while the support ring 34 is positioned above the O-ring 35. With this configuration, the sealing structure 30, which is stacked in multiple stages along the central axis, can be easily and reliably installed within the hollow portion 31. The support ring 34, the hollow cylindrical / flange composite member 33, and the C-ring 32 will be described later with reference to Figures 3 and 4.

[0035] A combination (unit) consisting of one O-ring 35, two support rings 34, one hollow cylindrical-flange composite member 33, and one C-ring 32 is denoted by the symbol C32-35. The sealing structure 30 is composed of multiple stages of such units C32-35. Figure 2 shows the units C32-35 stacked in two stages. With the sealing structure 30 having this configuration, multiple stages of seals can be arranged, and high-pressure hydrogen leakage can be reliably prevented without increasing the inner diameter of the hollow portion 31 in which the valve stem actuation shaft 13 (valve stem 1, etc.) slides. Here, since the units C32-35 include support rings 34, phenomena such as the O-ring 35 biting into the gap in the sliding portion of the valve stem 1 (O-ring protrusion) due to high pressure can be prevented. Although not shown, a cup-shaped seal can be used instead of the O-ring 35. In this case, it is preferable to arrange the cup-shaped seal with the top open as shown in Figure 2.

[0036] For example, the sealing structure 30 can be provided in the flow passage 3 of the shut-off valve 100 shown in Figures 5 to 8. The sealing structure 30 can also be provided in the flow passage 3-1 of the flow regulating valve 200 shown in Figures 9 to 16.

[0037] The support ring 34 is made of resin. As described above, the support ring 34 fills the gap between the inner wall of the flow passage 3 and the O-ring 35, and prevents a portion of the O-ring 35 from protruding due to high pressure and entering the gap between it and the inner wall of the flow passage 3 (O-ring).This prevents the O-ring 35 from "protruding" and prevents it from breaking at the insertion point. To reliably prevent this "protrusion" of the O-ring 35, in the illustrated embodiment, two support rings 34 are arranged to clamp the O-ring 35 from above and below.

[0038] The hollow cylindrical / flange composite member 33 will be described with reference to FIG3. The composite member 33 is made of metal and has a hollow cylindrical body 33A extending along the central axis direction (vertical direction) and a flange 33B located above the body 33A and extending radially outward (the flange 33B located at the upper edge of the body 33A). When assembling the composite member 33, the body 33A is inserted into the hollow portion 32A of the C-ring 32. This prevents the C-ring 32 from contracting radially inward.

[0039] The C-ring 32 will be described with reference to FIG4. The C-ring 32 is made of metal and is cut at approximately equal intervals in the circumferential direction at multiple locations to form a plurality of slits 32B (four in FIG3). The formation of slits 32B makes it easier for the C-ring 32 to shrink radially, thus making it easier to insert into the flow passage 3. The number of slits 32B may not be four (e.g., two to six). Here, a larger number of slits 32B means a larger radial dimension of the C-ring 32, and when the radial dimension of the C-ring 32 is large, the inner diameter of the hollow portion 31 is also large, thus making it easier to insert the support ring 34 into the hollow portion 31 by deforming it. If the support ring 34 can be inserted into the hollow portion 31, the sealing structure 30 according to the illustrated embodiment is not required. Therefore, it is not necessary to unnecessarily increase the number of slits 32B.

[0040] The thickness TS of the C-ring 32 in the central axis direction (the vertical direction in Figures 2 and 4) is set to be greater than its thickness TR in the radial direction. The ratio of the radial thickness TR of the C-ring 32 to the thickness TS in the central axis direction is set in the range of 1:1 to 1:10. If the axial thickness TS of the C-ring 32 is thicker, the C-ring 32 is less likely to shrink in the radial direction; if the central axis thickness TS is thinner, the C-ring 32 cannot resist the shear force acting in the central axis direction. In FIG4, although the radial thickness of the C-ring 32 is thinner at the slit 32B, the flange 33B of the hollow cylindrical body-flange composite member 33 covers the C-ring 32, so even if the radial dimension at the slit 32B is thinner, the flange 33B can withstand the load acting in the central axis direction, and therefore no problem occurs.

[0041] Next, referring to FIGS. 5 to 8, the application of the sealing structure 30 according to the embodiment of the present invention described in FIGS. 2 to 4 to the shut-off valve 100 will be described. The shut-off valve 100 is used, for example, as a filling device for filling high-pressure hydrogen into a fuel cell vehicle (FCV). FIGS. 5 and 6 show the shut-off valve 100 in the open state according to the illustrated embodiment. In FIG. 5, the shut-off valve 100It comprises: a housing 2, wherein a high-pressure hydrogen flow passage 3 (3A to 3E: see FIG. 6) extending along the central axis direction (up and down direction in FIG. 5) is formed inside the housing 2; a valve stem 1 disposed within the flow passage 3 and extending along the central axis direction; a valve body 1AT (conical portion: see FIG. 6) formed at the front end (upper end of valve stem 1); a valve seat 3AT (conical portion, see FIG. 6) formed near the end of the flow passage 3 within the housing 2 (near the lower end of the flow passage 3D in FIG. 6); and a valve closing mechanism 10 that presses the valve body 1AT against the valve seat 3AT. A sealing structure 30 described with reference to FIGS. 2 to 4 is provided on the sliding portion of the valve stem actuation shaft 13.

[0042] In FIG. 5, the valve closing mechanism 10 includes an actuator 11 and a valve closing force adjustment mechanism 50A. Actuator 11 is located near the end of the flow passage 3 opposite to the valve seat 1AT in the direction of the central axis (lower part in FIG1), and its function is to move valve stem 1 along the central axis. Valve closing force adjusting mechanism 50A includes elastic repulsion elimination device 20 and valve stem actuation shaft receiving device 40. The function of elastic repulsion elimination device 20 is to eliminate the elastic repulsion of spring 4, which has an elastic repulsion in the direction that causes valve stem 1 to sit on valve seat 3AT. Actuator 11 includes: actuator drive fluid supply section 12 for supplying or discharging actuator drive fluid (e.g., high-pressure air, high-pressure hydrogen); and transmission member 15. Transmission member 15 includes fluid supply section bottom 12A and spring clamping section 16, and transmits the actuator drive fluid supplied or discharged by actuator drive fluid supply section 12 to shaft support member 14, thereby converting it into movement in the direction of the central axis. Reference numerals 2-3 indicate the actuator side housing.

[0043] In the actuator 11, a shaft support member actuation spring 18 is provided below the transmission member 15, thereby surrounding the shaft 14A of the shaft support member 14, and the shaft 14A is connected to the spring clamping part 16 via the connecting part 16A. The spring 18, through its elastic repulsion, pushes the shaft support member 14 upward along the central axis direction via the transmission member 15 and the shaft 14A, and pushes the valve stem actuation shaft 13 and valve stem 1 upward along the central axis direction. In the state of FIG. 5, the driving fluid is supplied to the actuator driving fluid supply part 12, and the actuator driving fluid supply part 12 has a large thickness in the central axis direction (vertical direction).

[0044] The shaft 14A of the shaft support member 14 is provided in the valve stem actuation shaft receiving device 40, which is located at the intermediate position between the actuator 11 and the elastic repulsion elimination device 20. The shaft support member 14 is configured to have a diameter larger than that of the shaft 14A and to support the valve stem actuation shaft 13. The valve stem actuation shaft 13 is connected to the valve stem 1 and extends along the central axis. When the shut-off valve 100 shown in Figure 1 is opened...When open, the lower end of shaft 14A abuts against the stop 17 at the lower end of actuator 11. Conversely, when the shut-off valve 100 shown in Figures 7 and 8 is closed, the lower end of shaft 14A separates from the stop 17. A shaft support member recess 14B is formed on the upper part of shaft support member 14, and the base 13A of valve stem actuation shaft 13 is accommodated in the shaft support member recess 14B. Shaft support member 14 is connected to valve stem actuation shaft 13. Valve stem actuation shaft receiving device 40 is provided with a pressure regulating spring 144, which is disposed within hollow receiving portion 146 and surrounds shaft support member 14 and base 13A of valve stem actuation shaft 13. The lower part of pressure regulating spring 144 abuts against the bottom of hollow receiving portion 146, and the upper part of pressure regulating spring 144 abuts against valve stem actuation shaft engagement portion 142. Valve stem actuation shaft engagement portion 142 engages with base 13A of valve stem actuation shaft 13. In Figure 5, the valve closing mechanism 10 has a pressure transmission chamber 5, which houses the end of the valve stem 1 opposite to the valve body 1AT and the end of the valve stem actuation shaft 13 located on the valve stem 1 side. The pressure transmission chamber 5 is provided with a valve stem engagement portion 6 that engages with the valve stem 1, and one end (upper end) of the spring 4 is fixed to the valve stem engagement portion 6. The pressure transmission chamber 5 houses a lower end support member 7 of the spring, and the lower end support member 7 of the spring has a flange 7A that can contact the other end of the spring 4. The lower end support member 7 of the spring houses the end of the valve stem actuation shaft 13 located on the valve stem 1 side, and the valve stem actuation shaft 13 is connected to the valve stem 1 via the valve stem engagement portion 6 and the lower end support member 7 of the spring.

[0045] The elastic repulsion elimination device 20 has a pressure transmission chamber 5, a spring 4, and a lower end support member 7 of the spring. High-pressure hydrogen from the filling device (not shown) flows into the pressure transmission chamber 5 through the inlet 2A, the inlet-side flow passage 3A, the flow passage space 3B, and the valve actuation flow passage 3C (FIG. 6) of the housing 2, and the fluid pressure acts on the pressure transmission chamber 5. When the pressure in the pressure transmission chamber 5 rises above a predetermined value (specifically set according to the elastic repulsive force of the spring 4), the lower end support member 7 of the spring moves away from the spring 4, and when the pressure in the pressure transmission chamber 5 is equal to or lower than the predetermined value, the lower end support member 7 of the spring contacts the spring 4.

[0046] In FIG. 5, high-pressure hydrogen flows into the shut-off valve 100 from the inlet 2A and is discharged from the outlet 2B toward the downstream (FCV) device. FIG. 6 shows details of the high-pressure hydrogen flow passage 3 connecting the inlet 2A and the outlet 2B. In FIG. 6, the housing 2 is formed with an inlet 2A for high-pressure hydrogen, and the inlet 2A is connected to the valve actuation flow passage 3C via the inlet-side flow passage 3A and the flow passage space 3B. The flow passage space 3B also leads to the discharge outlet 2B via the discharge outlet side flow passages 3D and 3E. The metal valve stem 1 is disposed within the hollow portion of the valve actuation flow passage 3C and the flow passage space 3B of the housing 2.The front end of rod 1 (upper end in FIG. 6) forms a valve body 1AT with a conical surface. A conical surface is formed at the end of the flow passage space 3B on the discharge side flow passage 3D, and this conical surface forms a valve seat 3AT. The valve seat 3AT and the valve body 1AT form a shut-off valve.

[0047] When the shut-off valve shown in FIG. 5 and FIG. 6 is in the open state, the conical surface forming the valve seat 3AT is separated from the conical surface forming the valve body 1AT. On the other hand, when the shut-off valve shown in FIG. 7 and FIG. 8 is in the closed state, the conical surface forming the valve body 1AT is seated on the valve seat 3AT. FIG. 6 shows the open state of the shut-off valve, in which high-pressure hydrogen gas supplied from the inlet 2A (arrow A1) flows into the flow passage space 3B and is discharged from the discharge outlet 2B to the downstream side (FCV side) of the equipment via the discharge side flow passages 3D and 3E (arrow A2).

[0048] To change the shut-off valve 100 shown in FIG. 5 from the closed state shown in FIG. 7 and FIG. 8 to the open state shown in FIG. 5, actuator drive fluid is supplied to the actuator drive fluid supply unit 12. The fluid pressure of the supplied drive fluid causes the bottom 12A of the fluid supply unit and the spring clamping unit 16 to descend in the direction of arrow D, overcoming the elastic repulsive force of the shaft support member actuation spring 18. As the spring clamping unit 16 descends, the shaft support member 14 descends in the direction of arrow D, and the valve stem actuation shaft 13 connected to the shaft support member 14 also descends in the direction of arrow D. The valve stem 1, connected to the valve stem actuation shaft 13 via the valve stem engagement unit 6 and the lower spring support member 7, also descends in the direction of arrow D. As the valve stem 1 descends, the valve body 1AT (FIG. 6) separates from the valve seat 3AT (FIG. 6), and the shut-off valve 100 opens.

[0049] In the shut-off valve 100 shown in FIG. 5, FIG. 7 shows the state immediately after the shut-off valve 100 is closed, in the state where high-pressure hydrogen flows from the shut-off valve 100 and high pressure acts on the flow passage space 3B (FIG. 6). In order to close the shut-off valve 100 from the open state shown in FIG. 5 to the state shown in FIG. 7, actuator-driven fluid (e.g., high-pressure air, high-pressure hydrogen) is discharged from the actuator-driven fluid supply section 12. This discharge reduces the pressure in the actuator-driven fluid supply section 12, and due to the elastic repulsive force of the shaft support member operating spring 18, the fluid supply section bottom 12A and the spring clamping section 16 rise in the direction of arrow U. When the spring clamping section 16 rises, the shaft support member 14, the valve stem operating shaft 13, and the valve stem 1 connected to the valve stem operating shaft 13 also rise in the direction of arrow U.

[0050] When the spring clamping part 16 rises, the shaft support member 14 rises in the direction of arrow U, and the elastic repulsive force of the pressure regulating spring 144 acts on the base 13A of the valve stem actuation shaft 13 via the valve stem actuation shaft engagement part 142, thereby causing the valve stem actuation shaft 13 to rise in the direction of arrow U. As a result, the lower end support member 7 of the spring presses against the valve stem engagement part to actuate the spring 4, and the valve stem engagement...The elastic repulsive force of the actuating spring 4 causes the valve stem 1 to rise via the valve stem engagement 6. As the valve stem 1 rises, the valve body 1AT (FIG. 6) at the front end of the valve stem 1 sits on the valve seat 3AT (FIG. 6), and the shut-off valve 100 closes. In other words, as the valve stem actuating shaft 13 rises in the direction of arrow U, the elastic repulsive forces of the pressure regulating spring 144 and the valve stem engagement actuating spring 4 act, and cooperate with the pressure of the high-pressure hydrogen gas, closing the shut-off valve 100.

[0051] According to the embodiment shown in the figure, when a predetermined time has elapsed from the state shown in FIG. 7, the elastic repulsive forces of the valve stem engagement actuating spring 4 and the pressure regulating spring 144 disappear. The mechanism for making the elastic repulsive forces of the valve stem engagement actuating spring 4 and the pressure regulating spring 144 disappear will be described below with reference to FIG. 6 and FIG. 8, which show the state after a predetermined time since the shut-off valve 100 has closed. As shown in Figure 7, even if the valve body 1AT (Figure 6) at the front end of the valve stem 1 is seated on the valve seat 3AT (Figure 6) and the shut-off valve 100 is closed, the high-pressure hydrogen gas supplied to the suction port 2A in Figure 6 will flow through the suction port side flow passage 3A and flow passage space 3B, flow through the valve actuation flow passage 3C, and flow into the pressure transmission chamber 5. The pressure of the high-pressure hydrogen gas acts on the flange 7A of the lower end support member 7 of the spring, thereby causing the flange 7A of the lower end support member 7 of the spring to move downward in the direction of arrow D.

[0052] When the flange 7A of the lower end support member 7 of the spring descends more than a predetermined amount in the direction of arrow D, as shown in Figure 8, the actuator 11 side end (lower end) of the valve stem engagement actuation spring 4 separates from the flange 7A of the lower end support member 7 of the spring. As a result, the valve stem engagement actuation spring 4 is released from the compressed state and enters the extended state, and the elastic repulsive force that lifts the valve stem engagement 6 in the direction of arrow U disappears. When the valve stem engagement actuation spring 4 extends and the flange 7A of the lower spring support member 7 descends in the direction of arrow D, the valve stem actuation shaft 13 is also pushed downward. As a result, the shaft support member 14 also descends in the direction of arrow D, causing the pressure regulating spring 144 to extend and its elastic repulsive force to disappear. Thus, the force required for the conical surface 1AT (valve body, FIG. 2) at the front end of the valve stem 1 to sit on the conical surface 3AT (FIG. 2) to close the shut-off valve 100 is reduced by the elastic repulsive force of the valve stem engagement actuation spring 4 and the elastic repulsive force of the pressure regulating spring 144, ultimately leaving only the pressure of the high-pressure hydrogen. Moreover, since this force is reduced by the elastic repulsive force of the valve stem engagement actuation spring 4 and the pressure regulating spring 144, damage to the valve body 1AT and the valve seat 3AT is also reduced. Although not shown in the figure, in the illustrated embodiment, in addition to fluid pressure, an electric motor can also be used to open and close the shut-off valve.

[0053] Next, the flow regulating valve 200 using the sealing structure 30 shown in Figures 2 to 4 will be described with reference to Figures 9 to 16.Here, the sealing structure 30 is shown in Figures 9 and 10. The flow regulating valve 200 shown in Figures 9 to 16 is also used for filling high-pressure hydrogen into a fuel cell vehicle (FCV). In Figure 9, high-pressure hydrogen flows in from inlet 2A-1 (arrow A1) and is supplied downstream of outlet 2B-1 via flow path regulating unit B (arrow A2). Flow path regulating unit B has valve body 1AT-1 (Figure 11) and valve seat 3AT-1 (Figure 11) and has the function of regulating the flow rate by adjusting the valve opening. Details of flow path regulating unit B will be described later with reference to Figure 11. In Figures 9 and 10, the sealing structure 30 is located in the area where the valve stem 1-1 slides, extending along the central axis of the main body housing 2-1.

[0054] In Figures 9 and 10, the flow regulating valve 200 includes: a main body housing 2-1 (Figure 11), in which a flow passage 3-1 constituting the flow passage regulating part B is formed; a valve stem 1-1 having a front end 1A-1 (Figure 11); a valve stem support 43 supporting the valve stem 1-1; a cam plate 41, in which an inclined surface is formed on a surface 41A (cam plate surface: Figure 9); a cam follower (cam follower) 42; and an electric motor (drive source) 50, which rotates and drives the cam plate 41 via a reduction mechanism 51. A spring 45 is provided between the abutment portion 2E on the main body 2-1 side and the abutment portion 43E of the valve stem support 43, and the cam follower 42 is always pressed against the cam plate 41 by the spring 45, so that the cam follower 42 does not move away from the cam plate surface 41A. Reference numeral 44 indicates the cam plate side housing, and reference numeral 46 indicates the valve stem support housing.

[0055] As will be described later with reference to FIG. 16, an inclined surface is formed on the surface 41A of the cam plate 41 (the upper surface in FIG. 9 and FIG. 10), and the lower surface is flat. The thickness of the cam plate 41 in the direction of the central axis varies smoothly along the circumferential direction of the cam plate 41. The cam follower 42 is configured as a rod in general and has cam plate contact bearings 42A (e.g., roller bearings: FIG. 10) near both ends. The cam plate contact bearings 42A are rotatably pressed against the surface 41A of the cam plate 41. The two ends of the cam follower 42 have elongated bore contact bearings 42B (e.g., ball bearings: FIG. 10), which are inserted into elongated holes 44A (FIG. 12) formed in the cam plate side housing 44 and are configured to move smoothly in the longitudinal direction (up and down) within the elongated holes 44A.

[0056] The cam follower 42 is connected via a connecting bearing 42C (e.g., a roller bearing: FIG. 10) to the base 43A of the valve stem support 43 extending along the central axis C, the base 43A being located at a position corresponding to the center of the cam plate 41. The other end of the valve stem support 43 is connected to the valve stem 1-1. When the cam plate 41 is rotated by the motor 50 and the reduction mechanism 51, due to the cam...The inclined surface 41A of plate 41 causes the cam follower 42 and valve stem support 43 to move along the central axis C, thereby adjusting the valve opening of the flow regulating valve 200. Although not clearly shown, a control unit CU is provided, which controls the flow rate of the flow regulating valve 200 based on the amount of rotation of the output shaft of the motor 50.

[0057] The flow passage regulating part B in Figures 9 and 10 will be described in detail with reference to FIG. 11. In FIG. 11, a flow passage 3-1 is formed in the main body 2-1, and the flow passage 3-1 has a small diameter flow passage 3A-1 communicating with the outlet 2B-1, a large diameter flow passage 3B-1 communicating with the inlet 2A-1, and a tapered flow passage 3AT-1 connecting the two. The tapered flow passage 3AT-1 constitutes a valve seat. A valve stem tip tapered portion 1AT-1 is formed on the inlet 2A-1 side (lower side in Figure 11) of the valve stem tip 1A-1, and the valve stem tip tapered portion 1AT-1 is connected to the valve stem 1-1. The valve stem tip tapered portion 1AT-1 constitutes the valve body. In Figure 11, there is a radially small annular gap δ between the outer periphery of the valve stem tip 1A-1 and the inner circumferential surface of the flow passage small diameter portion 3A-1. When the flow regulating valve 200 is open and hydrogen flows through this annular gap δ, the hydrogen flow rate through the flow regulating valve 200 is relatively small. The axial length Lt of the valve stem tip 1A-1 inserted into the flow passage small diameter portion 3A-1 is the distance that hydrogen flows through the annular gap δ, and the flow passage resistance formed by the annular gap δ changes with the length Lt, and the hydrogen flow rate also changes accordingly. When the valve stem tip 1A-1 is located in the large diameter section 3B-1 of the flow passage, the hydrogen flow rate through the flow regulating valve 200 is large.

[0058] By adjusting the axial length Lt of the valve stem, the flow regulating valve 200 can continuously switch between the valve closed state (the valve stem tip tapered section 1AT-1 is seated on the flow passage tapered section 3AT-1), the small flow state (as shown in FIG. 11), and the large flow state (the valve stem tip 1A-1 is located in the large diameter section 3B-1 of the flow passage). By continuously and smoothly changing the length Lt to change the flow passage resistance, hydrogen flows at a small flow rate immediately after opening from the closed state, and then the small flow rate gradually increases, while when the valve stem tip 1A-1 is located in the large diameter section 3B-1 of the flow passage, the hydrogen flow rate increases rapidly.

[0059] In FIG. 12, elongated holes 44A are formed on both sides of the cam plate side housing 44, and the elongated hole contact bearing 42B (see FIG. 13) arranged on the end of the cam follower 42 is inserted into the elongated hole 44A. With this configuration, when the cam plate 41 (Fig. 13) rotates due to the rotation of the motor 50, the valve stem support 43 (Fig. 13) and the valve stem 1 (Figs. 9 and 10) can be prevented from rotating about their central axis, thereby preventing the valve stem 1 from not moving along the central axis direction (arrow C direction).

[0060] In Figures 13 and 14, cam follower 42 is provided with cam contact bearings 42A and elongated bore contact bearings 42B at both ends, and cam follower 42 presses against the surface 41A of cam plate 41 via cam plate contact bearings 42A. In Figure 14, cam plate surface 41A has an inclined surface 41S, a flat surface 41F, and a stepped portion 41ST. The inclined surface formed on cam plate surface 41A will be described later with reference to Figure 16.

[0061] In Figures 14 and 15, gear 51-1 is integrally formed with cam plate 41, and gear 51-1 is the gear constituting reduction mechanism 51 and closest to cam plate 41. When the cam plate 41 rotates, the two cam plate contact bearings 42A near the two ends of the cam follower 42 are squeezed by the inclined surface of the cam plate surface 41A (two inclined surfaces that are point-symmetric about the center point of the cam plate surface 41A), and the cam follower 42 moves along the central axis C in Figures 13 and 14. If the cam follower 42 moves along the central axis C, the valve stem front end 1A-1 and the valve body 1AT-1 (Figure 11) also move along the central axis C, and the dimension Lt (Figure 11) of the valve stem front end 1A-1 inserted into the small diameter part 3A-1 (Figure 11) of the flow passage changes, and the valve opening of the flow regulating valve 200 changes accordingly. By controlling the rotation angle of the cam plate 41, the valve opening of the flow regulating valve 200 can be controlled.

[0062] In Figure 15, the gear 51-1 is integrally formed with the cam plate 41, and the gear 51-1 is the gear closest to the cam plate 41 in the reduction mechanism 51. A thrust bearing 51A-1 is provided on the surface of gear 51-1 opposite to the side of cam plate 41 (the lower surface in FIG. 10), so that it can operate smoothly and reliably even when high pressure is applied.

[0063] The inclined surface (and plane) formed on the surface 41A of cam plate 41 corresponding to the movement (displacement) of valve stem 1-1 will be described with reference to FIG. 16. In FIG. 16, two inclined surfaces 41S-1 and 41S-2 of the same shape are formed on cam plate 41. Flat surfaces 41F-11 and 41F-12 are formed adjacent to inclined surface 41S-1 in the circumferential direction, and flat surfaces 41F-21 and 41F-22 are formed adjacent to both ends of inclined surface 41S-2 in the circumferential direction. Inclined surfaces 41S-1 and 41S-2, flat surfaces 41F-11 and 41F-12, and flat surfaces 41F-21 and 41F-22 are point-symmetric about the center of cam plate 41. Two cam plate contact bearings 42A (Figs. 10, 13, and 14) located near both ends of the driven rod 42 press against two inclined surfaces 41S-1 and 41S-2.

[0064] In Fig. 16, the flat surface 41F is provided to prevent the motor 50 from rotating too much and the cam plate 41 from rotating too much.For a long time, the valve opening was accidentally adjusted. This prevents damage to the valve seat 3AT-1 and valve stem 1-1. Inclined surfaces 41S-1 and 41S-2 protrude gradually relative to flat surfaces 41F-11 and 41F-21 from the same height as flat surfaces 41F-11 and 41F-21, along the central axis direction (direction of arrow SU in Figure 16) and simultaneously extend in the circumferential direction (arrow CL). Inclined surfaces 41S-1 and 41S-2 pass through their most protruding positions along the arrow SU direction and reach flat surfaces 41F-12 and 41F-22. Steps 41ST are formed at the boundaries between flat surfaces 41F-12 and 41F-21, and between flat surfaces 41F-22 and 41F-11, and the height of step 41ST in the arrow SU direction is indicated by the symbol H. The height H of step 41ST is the displacement of the valve stem front end 1A-1 as shown in Figure 11, which is equal to the movement of the valve stem front end 1A-1 from the closed position of the flow regulating valve 200 to the high flow position (the movement distance in the direction of the central axis of the valve stem 1-1 when the flow regulating valve 200 is opened quickly).

[0065] Referring to Figure 16, the valve opening and closing control of the flow regulating valve 200 by the rotation of the cam plate 41 is described for both normal valve opening and closing and valve opening quickly. In normal valve opening and closing, the valve opening degree of the flow regulating valve 200 is adjusted according to the amount of protrusion of the inclined surface 41S towards the valve stem 1-1 at the contact position between the cam plate contact bearing 42A and the inclined surface 41S (the amount of protrusion towards the arrow SU in Figure 16). That is, when the "protrusion" increases (when the contact position between the cam plate contact bearing 42A and the inclined surface 41S moves in the direction of arrow CL), the flow regulating valve 200 moves in the closing direction. On the other hand, when the "protrusion amount" decreases (when the contact position between the cam plate contact bearing 42A and the inclined surface 41S moves in the opposite direction of arrow CL), the flow regulating valve 200 moves in the opening direction. When the contact position between the cam plate contact bearing 42A and the inclined surface 41S moves forward in the valve closing direction and reaches the boundary with the flat surface 41F-12 or 41F-22, the flow regulating valve 200 closes. On the other hand, when the contact position between the cam plate contact bearing 42A and the inclined surface 41S moves in the valve opening direction and reaches the boundary with the flat surface 41F-11 or 41F-21, the flow regulating valve 200 opens.

[0066] In the case of rapid valve opening, when the cam plate 41 rotates, the contact position between the cam plate contact bearing 42A and the inclined surface 41S moves from the boundary with the flat surface 41F-11 or 41F-21 across the step portion 41ST to the flat surface 41F-11.When 11 or 41F-21, the regulating valve 200 rapidly transitions from the closed state to the open state. In the flow regulating valve 200 shown in Figures 9 to 16, the cam follower 42 can be omitted, and the motor 50 side end (lower end) of the cam follower 42 can be configured to contact and slide at a position radially outward from the center of the cam plate surface 41A. In this case, preferably, the motor 50 side end of the cam follower 42 constitutes a rolling bearing or a sliding bearing.

[0067] It should be noted that the embodiments shown are merely examples and are not intended to limit the technical scope of the invention.

[0068] [Symbol Explanation]

[0069] 1, 1-1 Valve stem

[0070] 1AT, 1AT-1 Valve body

[0071] 2, 2-1 Housing (Main housing)

[0072] 3, 3-1 Flow passage

[0073] 3A-1 Small diameter flow passage

[0074] 3B-1 Large diameter flow passage

[0075] 3AT, 3AT-1 Valve seat

[0076] 4 Valve stem joint actuation spring

[0077] 5 Pressure transmission chamber

[0078] 6 Valve stem joint

[0079] 7 Lower end support member of spring

[0080] 7A Lower end support member flange of spring

[0081] 10 Valve closing mechanism

[0082] 11 Actuator

[0083] 12 Actuator driven fluid supply unit instruction manual 9 / 10 Page 11 CN 121739182 A

[0084] 12A Bottom of fluid supply unit

[0085] 13 Valve stem operating shaft

[0086] 14 Shaft support component

[0087] 15 Transmission component

[0088] 16 Spring clamping part

[0089] 20 Elastic repulsion elimination device

[0090] 30 Sealing structure

[0091] 31 Hollow part

[0092] 31A Expanded diameter part (area with large inner diameter)

[0093] 32 C-ring

[0094] 32A Hollow part of C-ring

[0095] 33 Hollow cylindrical body / flange composite component

[0096] 33A Main body of hollow cylindrical body / flange composite component

[0097] 33B Flange of hollow cylindrical body-flange composite component

[0098] 34 Support ring

[0099] 35 O-ring

[0100] 41 Cam plate

[0101] 41A Cam surface

[0102] 42 Cam follower

[0103] 42A Rotating part (roller or bearing)

[0104] 43 Valve stem support

[0105] 50 Electric motor (drive source)

[0106] 51 Reduction mechanism

[0107] 100 Shut-off valve

[0108] 200 Flow regulating valve

[0109] C Valve stem center axis, etc. (see instruction manual)Page 10 / 10 12 CN 121739182 A Figure 1 Appendix 1 / 14 13 CN 121739182 A Figure 2 Appendix 2 / 14 14 CN 121739182 A Figure 3 Figure 4 Appendix 3 / 14 15 CN 121739182 A Figure 5 Appendix 4 / 14 16 CN 121739182 A Figure 6 Appendix 5 / 14 17 CN 121739182 A Figure 7 Appendix 6 / 14 18 CN 121739182 A Figure 8 Appendix 7 / 14 19 CN 121739182 A Figure 9 Appendix 8 / 14 20 CN 121739182 A Figure 10 Appendix 9 / 14 21 CN 121739182 A Figure 11 Figure 12 (Page 10 / 14, CN 121739182 A) Figure 13 (Page 11 / 14, CN 121739182 A) Figure 14 (Page 12 / 14, CN 121739182 A) Figure 15 (Page 13 / 14, CN 121739182 A) Figure 16 (Page 14 / 14, CN 121739182 A) Abstract The present invention provides a seal structure used in a type of valve in which a valve body is formed at the tip of a valve stem, and the valve is closed or opened by moving the valve stem in the central axial direction, in which a multi-stage seal is formed by continuously arranging multiple stages of annular sealing material in the area where the valve stem slides. The seal structure of the present inventionis characterized by including a plurality of stages of combinations of: a C-shaped member having a circular ring with a portion cut out in a circumferential direction of the circular ring; a composite member including a hollow cylindrical portion and a flange extending radially outward on a valve body side of the hollow cylindrical portion in a central axis direction of the hollow cylindrical portion, the hollow cylindrical portion being inserted into a central hollow portion of the C-shaped member; and a backup ring and an O-ring placed on the flange of the composite member.

Claims

1. A seal structure comprising a plurality of stages consisting of the group of: a C-shaped member having a circular ring, a portion of which is cut out in a circumferential direction of the circular ring; a composite member including a hollow cylindrical portion and a flange extending radially outward from the hollow cylindrical portion in a central axis direction of the hollow cylindrical portion on a valve body side of the hollow cylindrical portion, the hollow cylindrical portion being inserted into a central hollow portion of the C-shaped member; and a support ring and an O-ring disposed on the flange of the composite member.

2. A stop valve comprising: a housing having a fluid flow passage formed in a central axis direction; a valve stem provided in the flow passage and extending in the central axis direction; a valve body formed at a front end of the valve stem; a valve seat formed in the housing at a position near one end of the flow passage; and a valve closing mechanism for pressing the valve body against the valve seat, the valve closing mechanism consisting of an actuator and a valve closing force adjusting mechanism, wherein the valve closing force adjusting mechanism is provided in a pressure transmission chamber accommodating an end of the valve stem opposite to the valve body; a valve stem actuating shaft engaged with the valve stem and moved in the central axis direction by the actuator; and a pressure adjusting spring interposed between the actuator and the valve stem actuating shaft to adjust a pressing force of the valve stem actuating shaft, the seal structure as claimed in claim 1 being installed in a flow passage through which the valve stem actuating shaft extends to prevent fluid from flowing into the actuator side.

3. A flow regulating valve comprising: a cam plate having a slope formed on a surface thereof; a drive source for rotating the cam plate via a reduction mechanism; a cam follower having one of a rotating portion and a moving portion, the one being pressed against the surface of the cam plate and moving in a central axis direction of the flow regulating valve in response to an inclination of the surface of the cam plate; and a valve stem support portion connected at one end to the cam follower and at the other end to a valve stem, wherein flow is varied according to a size of the valve stem inserted into a flow passage small diameter portion, the seal structure as claimed in claim 1 being installed in an area in which the valve stem extending in the central axis direction of the housing slides. a cam plate having a slope formed on a surface thereof; a drive source for rotating the cam plate via a reduction mechanism; a cam follower having one of a rotating portion and a moving portion, the one being pressed against the surface of the cam plate and moving in a central axis direction of the flow regulating valve in response to an inclination of the surface of the cam plate; and a valve stem support portion connected at one end to the cam follower and at the other end to a valve stem, wherein flow is varied according to a size of the valve stem inserted into a flow passage small diameter portion, the seal structure as claimed in claim 1 being installed in an area in which the valve stem extending in the central axis direction of the housing slides.

Images