Flow Control Valve

Abstract

To provide a flow rate adjustment valve which handles a high-pressure gas as a work fluid, which can operate withstanding a load of a high pressure of the high-pressure gas without causing a friction.SOLUTION: A flow rate adjustment valve (100) includes: a cam panel (11) in which a slope is formed on a surface (cam panel surface); a drive source (20: for example, an electric motor) that rotationally drives the can panel (11) via a deceleration mechanism (21); a cam follower (12: cam follower rod) having a rotational part (12A: roller or bearing) that is pressed against a surface (11A: cam panel surface) of the can panel (11), and moving in a center axis direction (C) of the flow rate adjustment valve (100) (or shaft 1) by an inclination of the surface (11A) of the cam panel (11); and a shaft support part (13) with one end being connected to the cam follower (12) while the other end being connected to the shaft (1). A flow path cross-section area and flow rate change according to a dimension (Lt) of the shaft (1) inserted into a flow path small-diameter part (3A).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a flow control valve, and more particularly to a flow control valve (for example, needle valve type) for high-pressure gas. [Background technology]

[0002] There are types of flow control valves for high-pressure gas that adjust the valve opening by reciprocating the valve element of the high-pressure gas control valve in the axial direction of the shaft. Prior art for such flow control valves includes those in which the valve element or shaft is operated by an actuator such as a stepping motor (for example, Patent Document 1), and those in which a separate air valve is provided and operated by air. However, in the case of a flow control valve for high-pressure gas, the pressure of the high-pressure gas, which is the working fluid, acts on the valve element, so a large load is required to reciprocate the valve element, which poses the problem of increasing the size of the actuator or air valve itself, and also poses the problem of requiring equipment to control a large actuator or air valve itself.

[0003] Here, by using a rotating device such as a motor as a power source and converting rotational motion into linear motion using a screw mechanism, it is possible to adjust the valve opening by moving the valve element back and forth in the axial direction of the shaft.If a motor is used as the power source, it is possible to directly control the valve opening by controlling the motor. However, because the screw mechanism converts rotational motion into linear motion, the pressure of the high-pressure gas that serves as the working fluid acts on the threads of the screw mechanism, causing wear at the threaded engagement parts and resulting in durability problems. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-196001 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been proposed in view of the problems of the prior art described above, and aims to provide a flow control valve that uses high-pressure gas as the working fluid, that can withstand the load caused by the high pressure of the high-pressure gas while operating, and that is resistant to wear. [Means for solving the problem]

[0006] The flow control valve (100) of the present invention comprises: A flow rate control valve (100) that handles high-pressure hydrogen as a working fluid to be filled into a fuel cell vehicle, The surface (cam plate surface 11A) is inclined (set in accordance with the flow characteristics required for the flow control valve 100). disc-shaped A cam plate (11), a drive source (20: for example, an electric motor) that rotates and drives the cam plate (11) via a speed reduction mechanism (21); a cam follower (cam follower rod 12) that has a moving part (12A) that is pressed against the surface (11A: cam plate surface) of the cam plate (11) and moves in the direction of the central axis (C) of the flow control valve (100) (or shaft 1: valve stem) due to the inclination of the surface (11A) of the cam plate (11); A shaft support (13: valve stem support) having one end connected to the cam follower (12) and the other end connected to the shaft (1: valve stem). and, A cam plate side casing (14) that covers the cam follower (12) and A long hole (14A) is formed in the cam plate side casing (14), The cam follower (12) is formed in a rod shape, and at both ends thereof, there are provided a moving portion (12A) consisting of a rolling bearing that is rotatably pressed against the cam plate surface (11A) or a plain bearing that smoothly slides on the cam plate surface (11A), and a bearing (12B) that is inserted into an elongated hole (14A) formed in the cam plate side casing (14) and is movable in the longitudinal direction of the elongated hole (14A). The flow rate varies depending on the length (Lt) of the shaft (1) inserted into the small diameter portion (3A) of the flow passage.

[0007] In the present invention, it is preferable that the cam follower (12) is configured as a rod overall, has moving parts (12A) near both ends that are rotatably pressed against the surface (11A) of the cam plate (11), and has the center of the cam plate (11) connected to one end of a shaft support part (13) extending in the direction of the central axis (C). Here, it is preferable that the moving portion (12A) is formed of a rolling bearing (including a roller) that can rotate freely on the surface (11A) of the cam plate (11). Alternatively, the moving portion (12A) is preferably formed of a sliding bearing that smoothly slides on the surface (11A) of the cam plate (11). Furthermore, it is preferable that the cam follower (12) is composed of a rotatable cam follower roller (12-3), and the rotation axis of the cam follower roller (12-3) is supported on one end of a shaft support portion (13-1) extending in the direction of the central axis (C) from a position radially eccentric outward from the center of the cam plate (11-1).

[0008] In the present invention, it is preferable to provide a measuring device (22) that measures the rotation speed of the output shaft of the drive source (20: motor) or the rotation speed of a gear constituting the reduction gear mechanism (21), and to provide a control device (control unit CU: see FIG. 15) that controls the flow rate of the flow control valve (100) based on the measurement result of the measuring device (22).

[0009] The flow control valve (100) of the present invention comprises a shaft (1) with a small-diameter tip (1A) and a main body (2) in which a flow path (3) is formed, the shaft tip (1A) is arranged so as to be insertable into the small-diameter flow path portion (3A) of the flow path (3) formed in the main body (2), and a gap (δ) is set to exist between the outer periphery of the shaft tip (1A) and the inner circumferential surface of the small-diameter flow path portion (3A), and it is preferable that the valve opening or flow rate varies depending on the position of the shaft (1) in the direction of the central axis (C) relative to the flow path (3). [Effects of the Invention]

[0010] According to the present invention having the above-described configuration, the rotation of the drive source (20: electric motor) is transmitted via the speed reducer (21), causing the cam plate (11) to rotate. Since the surface (11A: cam plate surface) of the cam plate (11) is inclined (set in accordance with the flow characteristics required of the flow control valve 100), the follower (cam follower rod 12, moving portion 12A) pressed against and in contact with the cam plate surface (11A) moves in the direction of the central axis (C). As a result, the shaft (1) and valve element (1AT) connected to the follower (12) also move in the direction of the central axis (C). As a result, the position of the shaft (1) in the flow path (3) fluctuates, the dimension (Lt) of the shaft (1) inserted into the small diameter portion (3A) of the flow path fluctuates, and the cross-sectional area of ​​the flow path fluctuates. That is, the rotation of the cam plate (11) adjusts the position of the shaft (1) in the direction of the central axis (C), and the dimension (Lt) by which the shaft (1) is inserted into the small diameter portion (3A) of the flow path is adjusted, thereby realizing the flow rate characteristics required for the flow control valve (100).

[0011] In the present invention, a rotary device such as a drive source is used as a power source, and the cam plate (11) and cam followers (12, 12A) convert rotational motion into linear motion, thereby allowing the valve element to reciprocate in the axial direction of the shaft (1) and adjusting the valve opening. If a motor (20) is used as the drive source, the valve opening can be directly controlled by controlling the motor (20). According to the present invention, it is not the screw mechanism that converts rotational motion into linear motion, and the pressure of the high-pressure gas, which is the working fluid, does not act on the threads of the screw mechanism, so there is no wear on the threaded engagement parts, and the durability of the flow control valve is improved.

[0012] As described above, in a flow control valve for high-pressure gas, such as high-pressure hydrogen gas, the pressure of the high-pressure gas acts on the valve element, and so in the past, a large actuator or air valve was required to reciprocate the valve element. According to the present invention, by appropriately arranging bearings or rollers to reduce resistance, it is possible to rotate the cam plate (11) and adjust the position of the shaft (1) in the direction of the central axis (C) without using a large amount of power, so there is no need to provide a large actuator or air valve as in the prior art. By measuring the rotation amount of the motor (20) which is the driving source or the rotation amount of a predetermined location in the reduction mechanism (21), the positions of the cam plate surface (11) and the cam follower (12) can be identified, and by controlling the rotation amount of the motor (20) or the rotation amount of a predetermined location in the reduction mechanism (21), the axial position (C) of the shaft (1) can be accurately controlled, and therefore the flow rate of the high-pressure gas can be accurately controlled in accordance with the required characteristics. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an explanatory cross-sectional view of a flow rate adjustment valve according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory cross-sectional view showing a cross section perpendicular to FIG. [Figure 3] FIG. 1 is a characteristic diagram showing desirable flow control valve opening-hydrogen flow rate characteristics when filling a fuel cell vehicle (FCV) with hydrogen. [Figure 4] 4 is an enlarged explanatory cross-sectional view showing the relative positions of the shaft tip and the small diameter flow passage portion when the flow rate adjustment valve according to the illustrated embodiment is closed. FIG. [Figure 5] 10 is an enlarged explanatory cross-sectional view showing the relative positions of the shaft tip and the small diameter flow passage portion when the flow rate adjustment valve is in a small flow rate region. FIG. [Figure 6] 10 is an enlarged explanatory cross-sectional view showing the relative positions of the shaft tip and the small diameter flow passage portion at the boundary between the small flow rate region and the large flow rate region of the flow control valve. FIG. [Figure 7] 10 is an enlarged explanatory cross-sectional view showing the relative positions of the shaft tip and the small diameter flow passage portion in the state of the large flow rate region of the flow adjustment valve. FIG. [Figure 8] FIG. 3 is a perspective view of the flow rate adjustment valve shown in FIGS. 1 and 2. [Figure 9] FIG. 9 is a perspective view showing the configuration of FIG. 8 with the casing omitted. [Figure 10] FIG. 2 is a perspective view showing a cam plate, a cam follower rod, and a shaft support portion. [Figure 11] 11 is a view of the cam plate, the cam follower rod, and the shaft support portion shown in FIG. 10 as viewed from the arrow A11. [Figure 12] FIG. 4 is a perspective view showing a combination of a cam plate and a gear. [Figure 13] FIG. [Figure 14] 4 is a flowchart showing opening and closing control in the illustrated embodiment. [Figure 15] FIG. 15 is a block diagram for executing the control of FIG. 14. [Figure 16] FIG. 10 is a perspective view showing a main part of a first modified example of the illustrated embodiment. [Figure 17] FIG. 10 is a perspective view showing a main part of a second modified example of the illustrated embodiment. [Figure 18] FIG. 10 is a perspective view showing a main part of a third modified example of the illustrated embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. In the illustrated embodiment, the working fluid is, for example, high-pressure hydrogen gas. First, an embodiment of the present invention will be described with reference to FIGS. In Figure 1, which shows a cross section of a flow control valve 100 according to an embodiment, high-pressure hydrogen gas, which is the working fluid of the flow control valve 100, flows in from an inlet 2A (arrow A1) and is supplied downstream of an outlet 2B via a flow path adjustment section 10 (arrow A2). 1 and 2, the flow path adjustment unit 10 has a valve body and a valve seat, and has the function of adjusting the valve opening to adjust the flow rate. Details of the flow path adjustment unit 10 will be described later with reference to FIGS. 3 to 7. In FIG. 1, only the gears are shown hatched.

[0015] 1 and 2, the flow control valve, generally designated by the reference numeral 100, has a main body 2 (flow path adjustment unit casing), a shaft support 13 (valve stem support), a cam plate 11 with a sloped surface 11A (cam plate surface), a cam follower rod 12 (cam follower), and an electric motor 20 (drive source). A flow path 3 (FIGS. 4 to 7) is formed in the main body 2, and the flow path 3 constitutes the flow path adjustment unit 10. The shaft support 13 supports a shaft 1 (valve stem), and the shaft 1 has a shaft tip 1A (valve stem tip: FIG. 4 to FIG. 7). The electric motor 20 drives the cam plate 11 to rotate via a reduction mechanism 21. A spring 15 is interposed between the abutment portion 2E on the main body portion 2 side and the abutment portion 13E near the lower end of the shaft support portion 13, and the spring 15 presses the shaft support portion 13 (downward in Figures 1 and 2), thereby biasing the flow control valve 100 in the normally open direction. The flow control valve 100 has a cam plate side casing 14 and a shaft support part casing 16, and the cam plate side casing 14 covers the area from near the lower end of the shaft support part 13 to below the cam follower rod 12 and cam plate 11, and the shaft support part casing 16 covers the area from near the lower end of the main body part 2 to near the lower end of the shaft support part 13 and the spring 15.

[0016] As will be described later with reference to Figure 13, the cam plate 11 has a sloped surface 11A (the upper surface in Figures 1 and 2; the cam plate 11 is only referenced in Figure 1) and a flat lower surface. Therefore, the thickness of the cam plate (the thickness in the vertical direction in Figures 1 and 2) changes smoothly along the circumferential direction. The cam follower rod 12 is configured as a rod (bar) overall, and has cam plate contact bearings 12A (Fig. 2: rolling bearing: moving part) near both ends. The cam plate contact bearing 12A is pressed rotatably against the surface 11A of the cam plate 11 by the elastic force of a spring 15. A roller bearing, for example, is used as the cam plate contact bearing 12A. Although not shown, the moving part can be made up of a roller instead of the cam plate contact bearing 12A. As shown in Figure 2, oblong hole contact bearings 12B (Figure 2) are provided at both ends of the cam follower rod 12 (portions radially outward of the cam plate contact bearing 12A). The oblong hole contact bearings 12B are inserted into oblong holes 14A (see Figure 8; not shown in Figures 1 and 2) formed in the cam plate side casing 14, and are movable longitudinally (up and down in Figures 1 and 2) within the oblong holes 14A. The structure in which the oblong hole contact bearings 12B are inserted into the oblong holes 14A will be described later with reference to Figure 8. A ball bearing, for example, can be used as the oblong hole contact bearings 12B.

[0017] 2, cam follower rod 12 is connected to base 13A of shaft support 13, which extends in the direction of central axis C, at a position corresponding to the center (central part) of cam plate 11. At the connection between cam follower rod 12 and shaft support 13, cam follower rod 12 and shaft support 13 are connected via connection part bearing 12C. A roller bearing, for example, can be used as connection part bearing 12C. By mounting the cam plate contact bearing 12A and the connecting portion bearing 12C on the cam follower rod 12, the cam plate 11 can rotate smoothly even when the high pressure of compressed hydrogen gas is applied. The other end of the shaft support portion 13 (the end portion on the side remote from the cam follower rod 12: the upper end portion in FIGS. 1 and 2) is connected to the shaft 1.

[0018] 1 and 2, the reduction mechanism 21 is a mechanism that reduces the rotational speed of the output of the electric motor 20, which is the drive source, and transmits it, but is not limited to the structure shown in the figures, and any conventionally known structure can be applied. However, in the illustrated embodiment, a reduction mechanism with specifications and structure that can withstand operation under conditions where high-pressure hydrogen gas is added, such as by appropriately employing a thrust bearing, is used. The structure for attaching a thrust bearing to the gear of the reduction mechanism 21 will be described later with reference to FIG. 11. Gear 21-1 (Figure 2), which is the gear that constitutes the reduction mechanism 21 and is located closest to the cam plate 11, and the cam plate 11 are integrated by fitting a key 17 (Figure 2) (see Figures 11 and 12). Although not explicitly shown in Figures 1 and 2, the illustrated embodiment is provided with a control unit CU (control device: see Figure 15) that controls the flow rate of the flow control valve 100, and also has a measuring device (22: rotation amount sensor) that measures the amount of rotation of the output shaft of the electric motor 20 or the amount of rotation of the gears that make up the reduction mechanism (see Figure 15: not shown in Figures 1 and 2).

[0019] Next, the flow path adjustment unit 10 will be described with reference to FIGS. In Figure 3, the characteristics of the opening of the flow control valve and the hydrogen flow rate are shown by characteristic line L1 (L11, L12), and when the opening of the flow control valve is opened (moving to the right region on the horizontal axis of Figure 3) from a closed state (the origin of Figure 3), the opening gradually increases (moving to the upper region on the vertical axis of Figure 3) (the region near the origin of Figure 3).Then, the small flow rate region R1, where the opening is small, transitions to a large flow rate region R2 where the opening has increased. In the small flow rate region R1, the slope θ1 of the characteristic line L11 is small and the pressure rise is small, which reduces damage to the fuel tank and various piping of the fuel cell vehicle (FCV) being filled. On the other hand, in the large flow rate region R2, the slope θ2 of the characteristic line L12 is large, which increases the hydrogen flow rate and meets the demand for high-speed hydrogen filling. The operation of the flow rate adjustment valve in the small flow rate region R1 will be described with reference to FIGS. 4 to 6, and the operation of the flow rate adjustment valve in the large flow rate region R2 will be described with reference to FIG. In FIG. 3, the reference symbol L13 indicates the boundary between the small flow rate region R1 and the second flow rate region R2, and the state at the boundary L13 is shown in FIG.

[0020] In Figure 4, which shows the details of the flow path adjustment section 10, a flow path 3 (hydrogen gas flow path) is formed in the flow path forming section 2C of the main body 2, and the flow path 3 has a flow path small diameter section 3A that communicates with the outlet 2B, a flow path large diameter section 3B that communicates with the flow path inlet 2A (see Figure 1), and a flow path tapered section 3AT that connects them. A shaft tip tapered portion 1AT is formed on the inlet 2A side of the shaft tip 1A (the lower side in Figure 4), and the inlet 2A side of the shaft tip tapered portion 1AT is continuous with the shaft 1 (shaft main body: the part with a larger diameter than the shaft tip 1A). In the state shown in Fig. 4, the shaft tip 1A is inserted into the small diameter flow path portion 3A, and the shaft tip tapered portion 1AT abuts (engages or seats) on the flow path tapered portion 3AT. In the state shown in Fig. 4, the shaft tip 1A forms the valve body, the flow path tapered portion 3AT forms the valve seat, and the flow rate adjustment valve 30 is closed. In Figure 4, there is a circular gap δ with a minute radial dimension between the outer peripheral surface of the shaft tip 1A and the inner peripheral surface of the small diameter flow passage portion 3A. When the flow control valve 100, which is composed of the shaft tip tapered portion 1AT and the flow passage tapered portion 3AT, is open, hydrogen flows through the circular gap δ at a small flow rate. In this case, the hydrogen flow rate depends on the flow resistance in the circular gap δ, and this flow resistance is determined by the axial length Lt of the shaft, which is the length of the shaft tip 1A inserted into the small diameter flow passage portion 3A. The axial length Lt of the shaft is the distance (axial length of the shaft) that hydrogen gas flows through the circular gap δ.

[0021] FIG. 5 shows a state in which the shaft 1 (shaft tip 1A) has been moved downward from the state in FIG. 4 (state in which the valve is closed). 5, the shaft 1 (shaft tip 1A) has descended (compared to the state in FIG. 4), so the shaft tip tapered portion 1AT is separated from the flow path tapered portion 3AT, and the flow rate adjustment valve 100 is open. The length Lt of the shaft in the axial direction by which the shaft tip 1A is inserted into the flow path small diameter portion 3A is shorter than in the state in FIG. 5, the axial length Lt of the shaft is long, so the flow resistance in the annular gap δ is large and the flow rate of hydrogen gas in the gap δ is small. When the shaft tip 1 is further lowered and the axial length Lt of the shaft becomes shorter, the flow resistance in the gap δ decreases and the flow rate of hydrogen gas increases. In the flow control valve 100 according to the illustrated embodiment, the axial length Lt of the shaft, at which the shaft tip 1A is inserted into the small diameter flow path portion 3A, is changed to vary the flow path resistance, thereby enabling fine adjustment of the flow rate of hydrogen gas flowing through the annular gap δ.

[0022] In the state shown in Fig. 6, the end face 1AB of the shaft tip 1A is aligned with the boundary 3C between the small diameter flow path portion 3A and the tapered flow path portion 3AT, and the shaft axial length Lt (see Figs. 4 and 5; not shown in Fig. 6) is zero. The state shown in Fig. 6 is the state of the boundary L13 (Fig. 3) between the small flow rate region R1 (Fig. 3) and the large flow rate region R2 (Fig. 3) in the illustrated flow control valve 100. When the shaft 1 is further lowered from the state shown in FIG. 6, the state shown in FIG. 7 is reached.

[0023] In FIG. 7, an end face 1AB of the shaft tip 1A is located below a boundary 3C between the small diameter flow passage portion 3A and the tapered flow passage portion 3AT. In Figure 5, which shows the state of the small flow rate region, the flow path through which hydrogen gas flows is formed by the annular gap δ, and the flow path resistance is high. On the other hand, in the state shown in Figure 7, the flow path through which hydrogen gas flows is formed by the region between the outer circumferential surface of the shaft tip 1A and the inner circumferential surface of the flow path tapered portion 3AT, and its cross-sectional area is much larger than that of the annular gap δ shown in Figure 5, so the flow path resistance is low and the flow rate of hydrogen gas is high (large flow rate region). When the shaft 1 (shaft tip 1A) is further lowered, the cross-sectional area of ​​the flow path for hydrogen gas increases dramatically. With the illustrated flow control valve 100, the transitions of the valve from closed state to low flow state to high flow state are all made continuously by moving the shaft tip 1A in a direction away from the small diameter flow path portion 3A. With continuous and smooth operation, hydrogen gas flows at a low flow rate immediately after closing, i.e., when the valve is opened, and the low flow rate gradually increases (small flow rate region R1). After the state shown in Figure 6 (L13 in Figure 3), the hydrogen gas flow rate increases rapidly (large flow rate region R2). 3 to 7 are merely examples. The flow path adjustment unit A in the illustrated embodiment can also be configured in the same manner as the flow rate adjustment valve shown in Patent Document 1, for example.

[0024] The flow rate adjustment valve 100 shown in cross section in Figures 1 and 2 is shown in a perspective view in Figure 8. And Figure 9 shows the state in Figure 8 with the cam plate side casing 14 omitted. In Fig. 8, elongated holes 14A are formed on both side surfaces of the cam plate-side casing 14, elongated hole contact bearings 12B are inserted into the elongated holes 14A, and the elongated hole contact bearings 12B are disposed at the end of the cam follower rod 12 (see Fig. 9; however, the cam plate-side casing 14 is omitted in Fig. 9). With this configuration, when the cam plate 11 (Fig. 9) rotates due to the rotation of the electric motor 20 (drive source) transmitted via the reduction mechanism 21, the shaft support portion 13 (Fig. 9) and the shaft 1 (Figs. 1 and 2) rotate (co-rotate) around their central axes, preventing the shaft support portion 13 and the shaft 1 (Figs. 1 and 2) from moving in the central axis direction (the direction of arrow C in Figs. 8 and 9). 8 and 9, the reference numeral 2B denotes a discharge port for high-pressure hydrogen gas.

[0025] As shown in Figures 1, 2 and 9, the shaft support 13 is connected to the cam follower rod 12 so as to surround it (via the connecting portion bearing 12C), and the shaft support 13 and the cam follower rod 12 are pressed against the cam plate 11 by a spring 15. When the cam plate 11 is rotated by being driven by the electric motor 20 via the speed reducing mechanism 21, the shaft support portion 13 and the cam follower rod 12 move in the direction of the central axis C of the shaft 1 due to the inclination of the upper surface 11A of the cam plate 11.

[0026] 9 and 10, a cam contact bearing 12A and a long hole contact bearing 12B are provided at both ends of the cam follower rod 12, and the cam follower rod 12 is pressed against the surface 11A of the cam plate 11 via the cam contact bearing 12A. A slope is formed on the surface 11A of the cam plate 11, and the slope is formed as two slopes that are point-symmetrical with respect to the center of the central opening 11B (FIGS. 10 and 13) of the cam plate 11. The reason for forming the two slopes that are point-symmetrical is that each slope presses the two cam contact bearings 12A that are arranged near both ends of the cam follower rod 12 with the same pressure. 10, reference numeral 11F denotes a flat surface that constitutes a part of the cam plate surface 11A, and reference numeral 11ST denotes a step portion on the cam plate surface 11A. The surface 11A of the cam plate 11 will be described later with reference to FIG.

[0027] 9 and 10, when electric motor 20 (see FIGS. 1 and 2) rotates, the rotation is transmitted to cam plate 11 via speed reduction mechanism 21, causing cam plate 11 to rotate. As shown in FIGS. 10 and 11, gear 21-1, which is the gear that constitutes speed reduction mechanism 21 and is closest to cam plate 11, is integrated with cam plate 11. When the cam plate 11 rotates, the inclination of the cam plate surface 11A (two inclinations arranged point-symmetrically) causes the position of the cam plate surface 11A, with which the two cam plate contact bearings 12A near both ends of the cam follower rod 12 are in contact, to fluctuate along the central axis C, causing the cam follower rod 12 to move along the central axis C. When the cam follower rod 12 moves in the direction of the central axis C, the shaft 1 (Figures 1 and 2) moves via the shaft support part 13 (base part 13A) connected to the cam follower rod 12, thereby adjusting the valve opening degree of the flow control valve 100. In other words, by controlling the rotation angle of the cam plate 11, the position of the cam follower rod 12 in the direction of the central axis C can be adjusted, and the valve opening degree of the flow rate adjustment valve 100 can be controlled.

[0028] In the illustrated embodiment, a rotary device such as an electric motor 20 is used as a power source, and the cam plate 11 and driven rod 12 convert rotational motion into linear motion, thereby moving the valve element 1AT (FIGS. 4 to 7) back and forth in the axial direction of the shaft 1, thereby adjusting the valve opening. If the electric motor 20 is used as the drive source, the valve opening can be directly controlled by controlling the electric motor 20. Furthermore, in the illustrated embodiment, because the screw mechanism does not convert rotational motion into linear motion, the pressure of the high-pressure hydrogen gas, which is the working fluid, does not act on the threads of the screw mechanism, and wear or damage does not occur to the threaded engagement portion, thereby improving the durability of the flow control valve. Furthermore, by appropriately arranging bearings or rollers in the driven rod 12, shaft support portion 13, and reduction mechanism 21 to reduce resistance, the cam plate 11 can be rotated without using a large amount of power, and the position of the shaft 1 in the direction of the central axis C can be adjusted, eliminating the need for a large actuator or air valve as in the prior art. By measuring the amount of rotation of the electric motor 20, which is the driving source, or the amount of rotation at a predetermined location in the reduction mechanism 21, the positions of the cam plate surface 11A and the cam follower 12 can be identified, and by controlling the amount of rotation of the electric motor 20 or the amount of rotation at a predetermined location in the reduction mechanism 21, the position of the shaft 1 in the direction of the central axis C can be accurately controlled, making it possible to accurately control the flow rate of high-pressure gas in accordance with the required characteristics.

[0029] 11, which shows the back surface of cam plate 11 (the surface opposite to cam plate surface 11A), as described above, gear 21-1 of reduction mechanism 21, the gear closest to cam plate 11, is coupled to cam plate 11 by fitting key 17 (not shown: see FIG. 2). A thrust roller bearing 21A-1 is provided on the surface of gear 21-1 opposite to cam plate 11 (the lower surface in FIG. 11). By providing a thrust roller bearing 21A-1 on the surface of the gear 21-1 opposite to the cam plate 11, it is possible to withstand the compressive force applied by the high-pressure hydrogen gas. 12 shows the cam plate 11 and gear 21-1 integrated together, with an inclined surface 11S and a step portion 11ST formed on the cam plate surface 11A. The inclined surface 11S and step portion 11ST will be described later with reference to FIG. In FIG. 12, the thrust roller bearing 21A-1 (see FIG. 11) provided on the gear 21-1 is omitted.

[0030] A surface 11A of the cam plate 11 (cam plate surface: upper surface in the illustrated example) is formed with an inclination corresponding to the amount of movement (amount of displacement) of the shaft 1 (valve disc 1AT, FIGS. 4 to 7). In FIG. 13, the surface 11A of the cam plate 11 is formed with a flat surface 11F in addition to an inclined surface 11S. Two inclined surfaces 11S-1 and 11S-2 extending in the circumferential direction are formed so as to be point symmetrical about the center of the central opening 11B of the cam plate 11. Flat surfaces 11F-11 and 11F-12 are formed adjacent to both ends of the circumferential direction of inclined surface 11S-1, and flat surfaces 11F-21 and 11F-22 are formed adjacent to both ends of the circumferential direction of inclined surface 11S-2. These flat surfaces are also point symmetrical about the center of the central opening 11B of the cam plate 11, have the same shape, and extend in the circumferential direction. The two inclined surfaces 11S-1 and 11S-2 press the two cam plate contact bearings 12A (see FIGS. 2, 9 and 10) disposed near both ends of the driven rod 12 with the same pressure.

[0031] 13, flat surface 11F is provided to prevent the valve opening to be adjusted from deviating from a predetermined range due to excessive rotation of electric motor 20 and excessive rotation of cam plate 11. In other words, because flat surface 11F is provided, even if electric motor 20 and cam plate 11 rotate excessively, shaft 1 does not displace more than necessary, preventing the valve opening from becoming larger or smaller than a predetermined amount, and opening and closing of flow control valve 100 is carried out within a predetermined range. This makes it possible to prevent damage to valve seat 3AT and shaft 1. As shown in Fig. 13, the circumferential distance of flat surface 11F is shorter than that of inclined surface 11S. Inclined surfaces 11S-1 and 11S-2 start from the same height as flat surfaces 11F-11 and 11F-21, respectively, in the direction of movement of shaft 1 (the direction of arrow SU in Fig. 13), and gradually protrude relative to flat surfaces 11F-11 and 11F-21 (in the direction of arrow SU) as they move circumferentially (in the direction of arrow CL). Inclined surfaces 11S-1 and 11S-2 then reach flat surfaces 11F-12 and 11F-22 after passing their maximum protrusion in the direction of arrow SU. A step portion 11ST is formed at the boundary between the flat surface 11F-12 and the flat surface 11F-21, and at the boundary between the flat surface 11F-22 and the flat surface 11F-11. In Fig. 13, the height of the step portion in the direction of the arrow SU is indicated by the symbol H. The height dimension H (in the direction of the arrow SU) of the step portion 11ST is equal to the distance traveled by the central axis of the shaft when the valve at the shaft tip 1A in Figure 4 is rapidly opened, or the distance from the position of the shaft tip 1A in Figure 4 (the valve closing position of the flow control valve 100) to the position of the shaft tip 1A in Figure 7 (the high flow region of the flow control valve 100).

[0032] The manner in which the flow rate control valve 100 is controlled to open and close by the rotation of the cam plate 11 will be described for normal valve opening and closing and for rapid valve opening. During normal valve opening and closing, the cam plate contact bearings 12A (see Figures 2, 9, and 10) near both ends of the cam follower rod 12 rotate around the central opening 11B of the cam plate 11 while contacting the inclined surfaces 11S-1 and 11S-2 of the cam plate 11 (hereinafter, the two inclined surfaces will be collectively referred to as inclined surface 11S). At this time, the axial position of the shaft 1 is determined according to the amount by which the inclined surface 11S protrudes toward the shaft 1 at the contact position (abutment position) between the cam plate contact bearing 12A and the inclined surface 11S (the amount by which it protrudes toward the arrow SU in FIG. 13: protrusion amount), and the valve opening of the flow control valve 100 is adjusted. If the "protrusion amount" increases (for example, when the contact position moves in the direction of the arrow CL), the shaft 1 moves in the direction that closes the flow control valve 100. If the "protrusion amount" decreases (for example, when the contact position moves in the opposite direction to the arrow CL), the shaft 1 moves in the direction that opens the flow control valve 100. When the "amount of protrusion" increases (as the contact position advances in the direction of arrow CL) and the contact position reaches a position adjacent to flat surface 11F-12 or 11F-22 (a position on inclined surface 11S), the flow control valve 100 is closed. When the "amount of protrusion" decreases (as the contact position advances in the opposite direction of arrow CL) and the contact position reaches a position adjacent to flat surface 11F-11 or 11F-21 (a position on inclined surface 11S), the flow control valve 100 is opened.

[0033] When the cam plate 11 is rotated and the contact position (abutment position) between the cam plate contact bearing 12A and the inclined surface 11S moves further in the direction of arrow CL from the closed position, passes over the step portion 11ST, and moves to the other flat surface 11F-11 or 11F-21, the shaft 1 moves in the direction to open the flow control valve 100. This allows the flow rate adjustment valve 100 to be instantly changed from a closed state to a fully open state.

[0034] The opening and closing control of the flow rate adjustment valve 100 will be described mainly with reference to FIG. In the flowchart of Fig. 14, in step S1, the rotation amount of the electric motor 20 (Figs. 1 and 2) is measured by the rotation amount measuring device 22 (see Fig. 15). When measuring the rotation amount, instead of measuring the electric motor 20, the rotation amount of any one of the gears of the reduction mechanism 21 (Figs. 1 and 2) may be measured. In step S2, the valve opening degree of the flow rate adjustment valve 100 is calculated and determined based on the rotation amount of the electric motor 20 (or any gear of the reduction mechanism 21) measured in step S1. When calculating the valve opening of the flow control valve 100, the amount of movement of the shaft 1 in the direction of the central axis C is calculated based on the amount of rotation of the electric motor 20, etc., to calculate the valve opening of the flow control valve 100. Here, various parameters may be determined by calculation, but it is also possible to determine the necessary parameters by specifying in advance mathematical formulas or diagrams that show the interrelationships, etc., and obtaining those mathematical formulas or diagrams.

[0035] In the following step S3, the valve opening of the flow rate control valve 100 calculated and determined in step S2 is compared with a target value (the valve opening in FIG. 3). The target value of the valve opening is a target value using elapsed time as a parameter, for example, and has the characteristics shown in FIG. 3, but may also be determined by a parameter other than elapsed time. In step S4, based on the comparison result of step S3, it is determined whether the valve opening degree of the flow rate adjustment valve 100 determined in step S2 is within a predetermined range of the target value. If the result of the determination in step S4 is that the valve opening of the flow rate adjustment valve 100 is smaller than the predetermined range of the target value, the process proceeds to step S5, and if the valve opening is larger than the predetermined range of the target value, the process proceeds to step S6. If the valve opening degree of the flow rate adjustment valve 100 is within a predetermined range of the target value ("Yes" in step S4), the electric motor 20 is not rotated and the process proceeds to step S7.

[0036] In FIG. 14, in step S5 (when the valve opening degree is smaller than the predetermined range of the target value), the electric motor 20 is rotated by a predetermined small amount in the direction in which the valve opening degree of the flow rate adjustment valve 100 is increased. In step S6 (when the valve opening is greater than the predetermined range of the target value), the electric motor 20 is rotated by a predetermined small amount in the direction in which the valve opening of the flow rate adjustment valve 100 is decreased. In step S7, it is determined whether or not filling using the system including the flow rate adjusting valve 100 has finished. In step S7, if it is determined that "filling has ended" (step S7 is "Yes"), the control ends, and if "filling has not ended" (step S7 is "No"), the process returns to step S1 (a loop in which step S7 is "No"). Although not shown in Figure 14, in the case of rapid opening of the valve, it is determined whether the flow control valve 100 is in a closed state, and whether rapid opening should be performed. If rapid opening is to be performed, the electric motor 20 is controlled to rotate so that the contact position (abutment position) between the cam contact bearing 12A and the inclined surface 11S moves from the flat surface 11F-12, 11F-22 over the step portion 11ST to the flat surface 11F-21, 11F-11.

[0037] The control device CU (control unit) that controls the opening and closing of the flow rate adjustment valve 100 will be described with reference to FIG. In FIG. 15, a control unit CU (control device) has a valve opening degree determination block B1, a comparison block B2, a control signal output block B3, and a memory block B4. The valve opening degree determination block B1 acquires the detected value of the rotation amount from an electric motor rotation amount detection sensor 22 (measuring device) that measures the rotation amount of the electric motor 20 via a signal transmission line SL1. The valve opening determination block B1 acquires the "characteristics of the rotation amount of the electric motor 20 and the valve opening of the flow rate adjustment valve 100" stored in the memory block B4 via a signal transmission line SL2. The relationship between the rotation amount of the electric motor 20, the amount of protrusion in the central axial direction of the contact position between the cam plate inclined surface 11S and the cam follower rod 12 (the amount of movement in the central axial direction of the shaft 1 and the shaft tip 1A), and the valve opening of the flow control valve can be determined in advance. Then, using the predetermined relationship, the valve opening of the flow control valve can be calculated from the rotation amount of the electric motor 20, etc.

[0038] The valve opening determination block B1 has the function of calculating and determining the valve opening of the flow control valve 100 by comparing the detected value of the rotation amount of the electric motor 20 acquired with the "characteristics of the rotation amount of the electric motor 20 - valve opening of the flow control valve 100." The "valve opening degree of the flow rate adjustment valve 100" determined in the valve opening degree determination block B1 is sent to the comparison block B2 via a signal transmission line SL3.

[0039] The comparison block B2 acquires the target value of the valve opening of the flow rate adjustment valve 100 (for example, the target value with elapsed time as a parameter) from the memory block B4 via a signal transmission line SL4. The comparison block B2 has a function of comparing the valve opening of the flow rate adjustment valve 100 determined by the valve opening determination block B1 with the target value of the valve opening. The comparison result of the comparison block B2 is sent to the control signal output block B3 via a signal transmission line SL5.

[0040] The control signal output block B3 has a function of outputting a control signal to the electric motor 20 (or the speed reduction mechanism 21) via a signal transmission line SL6 based on the comparison result by the comparison block B2 so that the valve opening of the flow rate adjustment valve 100 becomes a target value (or a numerical value within a predetermined range from the target value). As explained in steps S5 and S6 of Fig. 14, this control signal is "a control signal for rotating the electric motor 20 in a direction that increases the valve opening of the flow rate adjustment valve 100" or "a control signal for rotating the electric motor 20 in a direction that decreases the valve opening of the flow rate adjustment valve 100." The memory block B4 has a function of acquiring in advance and storing information and data necessary for controlling the opening and closing of the flow control valve 100, and providing the information and data to each functional block as necessary. The information and data stored in the memory block B4 include, for example, specification data on the components that make up the flow control valve 100 (shaft 1, main body 2, flow path 3, cam plate 11, inclined surface 11S of the cam plate 11, cam follower rod 12, electric motor 20, and reduction mechanism 21), characteristics of the rotation amount of the electric motor 20 versus the valve opening degree of the flow control valve 100, a target value for the valve opening degree of the flow control valve 100, etc.

[0041] FIG. 16 shows a first variant of the illustrated embodiment. 1 to 15, as shown in Fig. 10, for example, a cam plate contact bearing 12A and a long hole contact bearing 12B are provided at both ends of cam follower rod 12, which is arranged to pass through shaft support portion 13, and cam plate contact bearing 12A rolls on surface 11A of cam plate 11. Cam plate contact bearing 12A constitutes a rolling bearing. In contrast, in the first modified example shown in Figure 16, slot-contact bearings 12B are provided at both ends of cam follower rod 12-1 that passes through shaft support portion 13, but no cam plate contact bearings or rolling bearings are provided. In Figure 16, the area of ​​cam follower rod 12-1 that is radially inward of slot-contact bearings 12B comes into contact with surface 11A of cam plate 11 and slides on surface 11A. In other words, the area of ​​cam follower rod 12-1 that is radially inward of slot-contact bearings 12B slides on surface 11A of cam plate 11. When the cam plate 11 rotates, the position of the cam plate surface 11A with which the cam follower rod 12-1 is in contact varies along the central axis C, causing the cam follower rod 12-1 to move along the central axis C, and the shaft 1 (Figures 1 and 2) to move, thereby adjusting the valve opening of the flow control valve 100. Other configurations and effects of the first modified example of FIG. 16 are similar to those of the embodiment of FIGS.

[0042] 16, cam follower rod 12-1 is a cylindrical member of a constant radius, and is in contact with an area ranging from the inner diameter to the outer diameter of cam plate 11. Due to the difference in the radius from the rotation axis (center axis C) at the contact point, the area of ​​contact between cam follower rod 12-1 and cam plate surface 11A at the same rotation speed is larger near the outer diameter than near the inner diameter of cam plate 11. Therefore, the amount of wear of cam follower rod 12-1 and / or cam plate surface 11A increases near the outer diameter of cam plate 11. In the second modification shown in Figure 17, a relatively large-diameter region 12-2A and a relatively small-diameter region 12-2B are provided in the region of the cam follower rod 12-2 radially inward of the bearing 12B, and a step is formed at the boundary between the large-diameter region 12-2A and the small-diameter region 12-2B. With this configuration, only the large-diameter region 12-2A slides on the cam plate surface 11A, so by appropriately setting the axial length of the large-diameter region 12-2A, the size of the contact area of ​​the cam follower rod 12-2 with the cam plate surface 11A can be adjusted. This reduces the difference in wear caused by the difference in radius from the center axis C. This large diameter region 12-2A may be constituted by a slide bearing. The other configurations and effects of the second modified example in FIG. 17 are the same as those of the first modified example in FIG.

[0043] FIG. 18 shows a third variant of the illustrated embodiment. 1 to 15, two cam contact bearings 12A contact the surface 11A of the cam plate 11, and the cam contact bearings 12A are provided near both ends of a cam follower rod 12 extending in the diameter direction of the cam plate 11. The cam follower rod 12 is connected to one end of a shaft support portion 13. The shaft support portion 13 extends in the center of the cam plate 11 in the direction of the central axis C (the direction of arrow C). In contrast, in the third modified example shown in Figure 18, the shaft support 13-1 extends in the direction of the central axis (indicated by arrow C) at a position offset radially outward from the center of the cam plate 11-1. Instead of a cam follower rod, a rotatably supported cam follower roller 12-3 (cam follower) is provided at the cam plate-side end of the shaft support 13-1, and moves on the cam plate surface 11A-1. The cam follower roller 12-3 is shaped like a thin disk and constitutes a rolling bearing.

[0044] As shown in Figure 18, approximately half of the cam plate surface 11A-1 is a flat surface 11F-1, and the remaining approximately half is an inclined surface 11S-1. A step portion 11ST-1 of height H is formed at the boundary between the flat surface 11F-1 and the position where the inclined surface 11S-1 protrudes most in the direction of the central axis (direction of arrow C). The shape of the cam plate surface 11A-1 is not point symmetrical with respect to the center of the cam plate 11-1 as shown in Figures 10 and 13 because the portion that comes into contact with the cam plate surface 11A-1 is a single cam follower roller 12-3. In FIG. 18, a rotation shaft (not shown) of a cam driven roller 12-3 is supported by each of the branched portions formed by bifurcating a base portion 13A-1 of a shaft support portion 13-1.

[0045] According to the third modified example in Fig. 18, the rotation of the cam plate 11-1 always causes the shaft support portion 13 to move up and down, so that the shaft 1 only rotates in the axial direction and does not move in the axial direction (direction of arrow C) (so-called "co-rotation"). Therefore, it is possible to avoid providing a co-rotation mechanism (a mechanism in which the elongated hole contact bearing 12B at the end of the cam follower rod 12 is inserted into the elongated hole 14A of the cam plate-side casing 14; see Fig. 8) as in the embodiment of Figs. 1 to 15. However, it is possible to provide a pin (not shown in Figure 18) extending radially outward on the shaft support portion 13-1 and insert the pin into a long hole (not shown in Figure 18) in a housing covering the outside of the shaft support portion 13-1, so that the valve body 1AT and the valve seat 3AT (see Figure 4) come into contact at the same position every time without rotating.

[0046] In Figure 18, as in the modified examples shown in Figures 16 and 17, it is possible to replace the cam follower roller 12-3 with a member (for example, a hemispherical member) that slides smoothly against the cam plate surface 11A, and the sliding member constitutes a sliding bearing. Although FIG. 18 shows only the cam plate 11-1, the shaft support portion 13-1, and the cam follower roller 12-3, the other configurations and effects are the same as those explained with reference to FIGS.

[0047] It should be noted that the illustrated embodiments are merely examples and are not intended to limit the technical scope of the present invention. [Explanation of symbols]

[0048] 1. Shaft (valve stem) 1A···Shaft tip 2. Main body 3. Flow path 3A: Small diameter flow passage 3B: Large diameter flow passage 11 Cam plate 11A Cam plate surface 12, 12-1, 12-3... Cam follower (cam follower rod or cam follower roller) 12A, 12A-1....moving part (roller or bearing) 13 Shaft support part (valve stem support part) 20. Electric motor (drive source) 21...Reduction mechanism 22. Measuring equipment 100 Flow control valve CU: Control unit (control device) Lt: The dimension where the shaft (small diameter shaft part) is inserted into the small diameter part of the flow passage δ Gap

Claims

1. A flow control valve (100) that handles high-pressure hydrogen as a working fluid to be filled into a fuel cell vehicle, a disc-shaped cam plate (11) having a slope formed on its surface (11A); a drive source (20) that rotates and drives the cam plate (11) via a speed reduction mechanism (21); a cam follower (12) that is pressed against a surface (11A) of the cam plate (11) and moves in the direction of the central axis (C) of the flow control valve (100) due to the inclination of the surface (11A) of the cam plate (11); a valve stem support (13) having one end connected to the cam follower (12) and the other end connected to the valve stem (1); The cam plate side casing (14) covers the cam follower (12), and a long hole (14A) is formed in the cam plate side casing (14). The cam follower (12) is configured in a rod shape, and at both ends thereof, there are provided a moving portion (12A) consisting of a rolling bearing that is rotatably pressed against the cam plate surface (11A) or a plain bearing that smoothly slides on the cam plate surface (11A), and a bearing (12B) that is inserted into an elongated hole (14A) formed in the cam plate side casing (14) and is movable in the longitudinal direction of the elongated hole (14A), A flow control valve characterized in that the flow rate varies depending on the dimension (Lt) of the valve stem (1) inserted into the small diameter portion (3A) of the flow path.

2. 2. The flow control valve of claim 1, wherein the cam follower (12) is a cam follower rod connected to one end of a valve stem support portion (13) extending in the central axis direction (C) at a position corresponding to the center of the cam plate.

Images