Flow rate adjustment 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 particularly to a flow control valve for high-pressure gas (for example, a needle valve type).

Background Art

[0002] As a flow control valve for high-pressure gas, there is a type in which the valve body of the high-pressure gas control valve reciprocates in the axial direction of the shaft to adjust the valve opening degree. In the prior art of such a type of flow control valve, there are those in which the valve body or the shaft is actuated by an actuator such as a stepping motor (for example, Patent Document 1), and those in which an air valve is separately provided and actuated by air. However, in the case of a flow control valve for high-pressure gas, since the pressure of the high-pressure gas as the working fluid acts on the valve body, a large load is required to reciprocate the valve body, and there is a problem that the actuator or the air valve itself becomes large. In addition, there is a problem that equipment for controlling the large actuator or the air valve itself is required.

[0003] Here, by using a rotary device such as a motor as a power source and converting the rotary motion into a linear motion by a screw mechanism, it is possible to reciprocate the valve body in the axial direction of the shaft to adjust the valve opening degree. And if a motor is used as the power source, it is possible to directly control the valve opening degree by controlling the motor. However, in order to convert the rotary motion into a linear motion by the screw mechanism, the pressure of the high-pressure gas as the working fluid acts on the screw thread of the screw mechanism, resulting in wear of the screw engagement portion and a problem in durability.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been proposed in view of the above-described problems of the prior art, and is a flow control valve that handles high-pressure gas as a working fluid, and aims to provide a flow control valve that can operate while withstanding the load due to the high pressure of the high-pressure gas and is less likely to cause wear.

Means for Solving the Problems

[0006] The flow control valve (100) of the present invention a cam plate (11) having an inclination (set corresponding to the flow characteristics required for the flow control valve 100) formed on the surface (cam plate surface 11A), a drive source (20: for example, an electric motor) that rotationally drives the cam plate (11) via a speed reduction mechanism (21), a cam follower (cam follower rod 12) having a moving part (12A) pressed against the surface (11A: cam plate surface) of the cam plate (11), and moving in the direction of the central axis (C) of the flow control valve (100) (or the shaft 1: valve rod) due to the inclination of the surface (11A) of the cam plate (11), a shaft support part (13: valve rod support part) having one end connected to the cam follower (12) and the other end connected to the shaft (1: valve rod), characterized in that the flow rate varies depending on the dimension (Lt) in which the shaft (1) is inserted into the small-diameter part (3A) of the flow path.

[0007] In the present invention, the cam follower (12) is preferably configured to be entirely rod-shaped, and moving parts (12A) that are rotatably pressed against the surface (11A) of the cam plate (11) are provided near both end portions, and the central portion of the cam plate (11) is connected to one end portion of a shaft support part (13) extending in the direction of the central axis (C). Here, the moving part (12A) is preferably composed of a rotatable rolling bearing (including a roller) that rotates on the surface (11A) of the cam plate (11). Alternatively, the moving part (12A) is preferably composed of a sliding bearing that smoothly slides on the surface (11A) of the cam plate (11). Further, the cam follower (12) is constituted by a rotatable cam follower roller (12-3), and it is preferable that the rotation axis of the cam follower roller (12-3) is supported at one end of a shaft support portion (13-1) extending in the direction of the central axis (C) from a position eccentric radially outward with respect to the central portion of the cam plate (11-1).

[0008] Also, in the present invention, it is preferable to provide a measuring device (22) for measuring the number of revolutions of the output shaft of the drive source (20: motor) or the number of revolutions of the gears constituting the speed reduction mechanism (21), and a control device (control unit CU: see FIG. 15) for controlling the flow rate of the flow rate adjustment valve (100) based on the measurement result of the measuring device (22).

[0009] In the flow rate adjustment valve (100) of the present invention, it includes a shaft (1) having a tip (1A) with a small diameter and a main body portion (2) in which a flow path (3) is formed. The shaft tip (1A) is disposed so as to be insertable into a flow path small diameter portion (3A) of the flow path (3) formed in the main body portion (2), and a gap (δ) is set to exist between the outer periphery of the shaft tip (1A) and the inner peripheral surface of the flow path small diameter portion (3A). It is preferable that the valve opening degree or the flow rate varies according to the position of the shaft (1) in the direction of the central axis (C) with respect to the flow path (3).

Advantages 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 reduction mechanism (21), and the cam plate (11) rotates. Since an inclination (set corresponding to the flow rate characteristics required for the flow rate adjustment valve 100) is formed on the surface (11A: cam plate surface) of the cam plate (11), the follower (cam follower rod 12, moving portion 12A) pressed 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 the valve body (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) in which the shaft (1) is inserted into the flow path small diameter portion (3A) fluctuates, and the flow path cross-sectional area fluctuates. That is, when the cam plate (11) rotates, the position of the shaft (1) in the direction of the central axis (C) is adjusted, and the dimension (Lt) of the shaft (1) inserted into the small-diameter portion (3A) of the flow path is adjusted, so that the flow rate characteristics required for the flow rate control valve (100) can be realized.

[0011] In the present invention, using a rotating device such as a drive source as a power source, by converting the rotational motion into a linear motion by the cam plate (11) and the cam followers (12, 12A), the valve body can reciprocate in the axial direction of the shaft (1) to adjust the valve opening degree. And if the motor (20) is used as the drive source, it is possible to directly control the valve opening degree by controlling the motor (20). According to the present invention, since the conversion of the rotational motion into the linear motion is not a screw mechanism and the pressure of the high-pressure gas, which is the working fluid, does not act on the thread of the screw mechanism, wear of the screw engagement portion does not occur, and the durability of the flow rate control valve is improved.

[0012] As described above, in a flow rate control valve for high-pressure gas such as high-pressure hydrogen gas, since the pressure of the high-pressure gas acts on the valve body, in order to reciprocate the valve body, a large actuator or an air valve has been conventionally required. According to the present invention, by appropriately arranging bearings or rollers 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. Therefore, it is not necessary to provide a large actuator or an air valve as in the prior art. And by measuring the rotation amount of the motor (20) as the drive source or the rotation amount at a predetermined position in the speed reduction mechanism (21), the positions of the cam plate surface (11) and the cam follower (12) are specified, and by controlling the rotation amount of the motor (20) or the rotation amount at a predetermined position of the speed reduction mechanism (21), the position of the shaft (1) in the axial direction (C) can be accurately controlled. Therefore, it is possible to accurately control the flow rate control of the high-pressure gas in accordance with the required characteristics.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the illustrated embodiment, the working fluid is, for example, high-pressure hydrogen gas. First, embodiments of the present invention will be described with reference to FIGS. 1 to 17. In FIG. 1 showing a cross section of the flow rate adjustment valve 100 according to the embodiment, the high-pressure hydrogen gas, which is the working fluid of the flow rate adjustment valve 100, flows in from the inlet 2A (arrow A1) and is supplied to the downstream side from the discharge port 2B via the flow path adjustment unit 10 (arrow A2). In FIGS. 1 and 2, the flow path adjustment unit 10 has a valve body and a valve seat, and has a function of adjusting the flow rate by adjusting the valve opening degree. Details of the flow path adjustment unit 10 will be described later with reference to FIGS. 3 to 7. In FIG. 1, only the gear is shown with hatching.

[0015] In FIGS. 1 and 2, the flow rate adjustment valve, indicated as a whole by reference numeral 100, has a main body part 2 (flow path adjustment part casing), a shaft support part 13 (valve rod support part), a cam plate 11 with an inclination formed on the 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 part 2, and the flow path 3 constitutes the flow path adjustment unit 10. The shaft support part 13 supports a shaft 1 (valve rod), and the shaft 1 has a shaft tip 1A (valve rod tip: FIGS. 4 to 7). The electric motor 20 rotationally drives the cam plate 11 via a speed reduction mechanism 21. A spring 15 is interposed between the contact part 2E on the main body part 2 side and the contact part 13E near the lower end of the shaft support part 13. The shaft support part 13 is pressed by the spring 15 (downward in FIGS. 1 and 2), and therefore the flow rate adjustment valve 100 is constantly biased in the open direction. The flow control valve 100 has a cam plate side casing 14 and a shaft support portion casing 16. The cam plate side casing 14 covers from near the lower end of the shaft support portion 13 to below the cam follower rod 12 and the cam plate 11. The shaft support portion casing 16 covers from near the lower end of the main body portion 2 to near the lower end of the shaft support portion 13 and the spring 15.

[0016] As will be described later with reference to FIG. 13, the cam plate 11 has an inclination formed on the surface 11A (the upper surface in FIGS. 1 and 2: only FIG. 1 is labeled for the cam plate 11), and the lower surface is configured as a flat surface. Therefore, the thickness of the cam plate (the thickness in the vertical direction in FIGS. 1 and 2) smoothly changes along the circumferential direction. The cam follower rod 12 is entirely configured in a rod shape (bar shape), and has cam plate contact bearings 12A (FIG. 2: rolling bearings: moving parts) near both ends. The cam plate contact bearings 12A are rotatably pressed against the surface 11A of the cam plate 11 by the elastic force of the spring 15. For example, roller bearings are used as the cam plate contact bearings 12A. Although not shown, the moving part can be configured by rollers instead of the cam plate contact bearings 12A. As shown in FIG. 2, long hole contact bearings 12B (FIG. 2) are provided at both ends of the cam follower rod 12 (the portions radially outside the cam plate contact bearings 12A). The long hole contact bearings 12B are inserted into long holes 14A formed in the cam plate side casing 14 (see FIG. 8: not shown in FIGS. 1 and 2), and are movable in the longitudinal direction (the vertical direction in FIGS. 1 and 2) within the long holes 14A. The structure in which the long hole contact bearings 12B are inserted into the long holes 14A will be described later with reference to FIG. 8. For example, ball bearings can be used as the long hole contact bearings 12B.

[0017] In FIG. 2, the cam follower rod 12 is connected to the base 13A of the shaft support portion 13 extending in the direction of the central axis C at a position corresponding to the central portion (center portion) of the cam plate 11. At the connecting portion between the cam follower rod 12 and the shaft support portion 13, the cam follower rod 12 and the shaft support portion 13 are connected via a connecting portion bearing 12C. As the connecting portion bearing 12C, for example, a roller bearing can be used. By interposing 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 a high pressure of compressed hydrogen gas is applied. The other end of the shaft support portion 13 (the end portion on the side separated from the cam follower rod 12: the upper end portion in FIGS. 1 and 2) is connected to the shaft 1.

[0018] In FIGS. 1 and 2, the speed reduction mechanism 21 is a mechanism that reduces and transmits the rotational speed of the output of the electric motor 20, which is a drive source, but is not limited to the illustrated structure, and a conventionally known structure can be applied. However, a speed reduction mechanism with a specification and structure that can withstand operation under a state where high-pressure hydrogen gas is applied, such as appropriately adopting a thrust bearing, is adopted in the illustrated embodiment. The structure of attaching a thrust bearing to the gear of the speed reduction mechanism 21 will be described later with reference to FIG. 11. The gear 21-1 (FIG. 2) provided at the position closest to the cam plate 11 among the gears constituting the speed reduction mechanism 21 and the cam plate 11 are integrated by fitting a key 17 (FIG. 2) (see FIGS. 11 and 12). Although not shown in FIGS. 1 and 2, in the illustrated embodiment, a control unit CU (control device: see FIG. 15) that controls the flow rate of the flow rate adjustment valve 100 is provided, and a measuring device (22: rotational speed sensor) that measures the rotational amount of the output shaft of the electric motor 20 or the rotational amount of the gears constituting the speed reduction mechanism is also provided (see FIG. 15: not shown in FIGS. 1 and 2).

[0019] Next, with reference to FIGS. 3 to 7, the flow path adjustment portion 10 will be described. In FIG. 3, the characteristics of the opening degree of the flow rate adjustment valve and the hydrogen flow rate are shown by characteristic lines L1 (L11, L12). When the opening degree of the flow rate adjustment valve is opened from the closed state (the origin in FIG. 3) (when moving to the right region on the horizontal axis of FIG. 3), the opening degree gradually increases (when moving to the upper region on the vertical axis of FIG. 3) (in the region near the origin of FIG. 3). Then, it shifts from the small flow rate region R1 where the opening degree is small to the large flow rate region R2 where the opening degree has increased. In the small flow rate region R1, since the slope θ1 of the characteristic line L11 is small and the pressure rise is also small, damage to the fuel tank and various pipes of the FCV (fuel cell vehicle) to be filled can be reduced. On the other hand, in the large flow rate region R2, since the slope θ2 of the characteristic line L12 is large, the hydrogen flow rate is large, and the requirement of performing hydrogen filling at high speed can be met. 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. 7. In FIG. 3, reference numeral 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. 6.

[0020] In FIG. 4 showing the details of the flow path adjustment unit 10, a flow path 3 (hydrogen gas flow path) is formed in the flow path forming unit 2C of the main body unit 2. The flow path 3 has a flow path small diameter part 3A communicating with the flow outlet 2B, a flow path large diameter part 3B communicating with the flow path inlet 2A (see FIG. 1), and a flow path taper part 3AT connecting them. A shaft tip taper part 1AT is formed on the flow path inlet 2A side (the lower side in FIG. 4) of the shaft tip 1A, and the flow path inlet 2A side of the shaft tip taper part 1AT is continuous with the shaft 1 (shaft main body: a part having a larger diameter than the shaft tip 1A). In the state of FIG. 4, the shaft tip 1A is inserted into the flow path small diameter part 3A, and the shaft tip taper part 1AT is in contact (engaged or seated) with the flow path taper part 3AT. In the state of FIG. 4, the shaft tip 1A constitutes the valve body, the flow path taper part 3AT constitutes the valve seat, and the flow rate adjustment valve 30 is closed. In FIG. 4, there is an annular gap δ with a very small radial dimension between the outer peripheral surface of the shaft tip 1A and the inner peripheral surface of the small-diameter flow path portion 3A. When the flow rate adjustment valve 100 composed of the shaft tip taper portion 1AT and the flow path taper portion 3AT is open, hydrogen flows through the annular gap δ at a small flow rate. The hydrogen flow rate in that case depends on the flow path resistance in the annular gap δ, and the flow path resistance is determined by the shaft axial length Lt in which the shaft tip 1A is inserted into the small-diameter flow path portion 3A. The shaft axial length Lt is the distance (shaft axial length) through which hydrogen gas flows in the annular gap δ.

[0021] The state in which the shaft 1 (shaft tip 1A) is moved downward in FIG. 4 from the state shown in FIG. 4 (the valve is closed) is shown in FIG. 5. In FIG. 5, since the shaft 1 (shaft tip 1A) has descended (compared to the state in FIG. 4), the shaft tip taper portion 1AT is separated from the flow path taper portion 3AT, and the flow rate adjustment valve 100 is open. And the shaft axial length Lt in which the shaft tip 1A is inserted into the small-diameter flow path portion 3A is shorter compared to the state in FIG. 4. In the state of FIG. 5, since the shaft axial length Lt is long, the flow path resistance in the annular gap δ is large, and the flow rate of the hydrogen gas flowing in the gap δ is small. When the shaft tip 1 further descends and the shaft axial length Lt becomes short, the flow path resistance in the gap δ becomes small, and the hydrogen gas flow rate increases. In the flow rate adjustment valve 100 according to the illustrated embodiment, the shaft axial length Lt in which the shaft tip 1A is inserted into the small-diameter flow path portion 3A is varied to vary the flow path resistance, whereby the flow rate of the hydrogen gas flowing through the annular gap δ can be finely adjusted.

[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 flow path taper portion 3AT, and the shaft axial length Lt (see FIGS. 4 and 5: not shown in FIG. 6) becomes 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 rate adjustment 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, the end face 1AB of the shaft tip 1A is located below the boundary 3C between the small-diameter flow path portion 3A and the flow path taper portion 3AT. In Fig. 5 showing the state in the low-flow region, the flow path through which hydrogen gas flows is constituted by the annular gap δ, and the flow path resistance is large. On the other hand, in the state shown in Fig. 7, the flow path through which hydrogen gas flows is constituted by the region between the outer peripheral surface of the shaft tip 1A and the inner peripheral surface of the flow path taper portion 3AT. Compared with the annular gap δ shown in Fig. 5, its cross-sectional area is much larger, the flow path resistance is small, and the flow rate of hydrogen gas is large (high-flow region). When the shaft 1 (shaft tip 1A) is further lowered, the cross-sectional area of the flow path of hydrogen gas increases dramatically. According to the illustrated flow rate adjustment valve 100, the transitions from the closed state of the valve → the low-flow state → the high-flow state are all continuously performed by an operation of moving the shaft tip 1A in a direction away from the small-diameter flow path portion 3A. By a continuous and smooth operation, hydrogen gas flows at a small flow rate immediately after closing, i.e., at the time of valve opening, and the small flow rate gradually increases (low-flow region R1). After the state shown in Fig. 6 (L13 in Fig. 3), the flow rate of hydrogen gas increases rapidly (high-flow region R2). Here, the configuration of the flow path adjustment portion A shown in Figs. 3 to 7 is merely an example. The flow path adjustment portion A in the illustrated embodiment can 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 Figs. 1 and 2 is shown in a perspective view in Fig. 8. And the state where the cam plate side casing 14 in Fig. 8 is omitted is shown in Fig. 9. In FIG. 8, long holes 14A are formed on both side surfaces of the cam plate side casing 14, and long hole contact bearings 12B are inserted into the long holes 14A. The long hole contact bearings 12B are arranged at the ends of the cam follower rod 12 (see FIG. 9. However, the cam plate side casing 14 is omitted in FIG. 9). With such a configuration, when the cam plate 11 (FIG. 9) rotates due to the rotation of the electric motor 20 (driving source) transmitted through the speed reduction mechanism 21, the shaft support portion 13 (FIG. 9) and the shaft 1 (FIGS. 1 and 2) rotate (orbit) around their central axes, and the situation where the shaft support portion 13 and the shaft 1 (FIGS. 1 and 2) do not move in the central axis direction (the direction of arrow C in FIGS. 8 and 9) is prevented. In FIGS. 8 and 9, what is indicated by reference numeral 2B is the discharge port of high-pressure hydrogen gas.

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

[0026] In FIGS. 9 and 10, bearing 12A for cam contact and bearing 12B for long hole contact are respectively 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 bearing 12A for cam contact. An inclination is formed on the surface 11A of the cam plate 11, and the inclination is formed as two inclinations that are point-symmetrical with respect to the center of the central opening 11B (FIGS. 10 and 13) of the cam plate 11. The two point-symmetrical inclinations are formed because each inclination presses the two bearings 12A for cam contact arranged near both ends of the cam follower rod 12 with the same pressure. Reference numeral 11F in FIG. 10 indicates a flat surface that forms part of the cam plate surface 11A, and reference numeral 11ST indicates a stepped portion on the cam plate surface 11A. The surface 11A of the cam plate 11 will be described later with reference to FIG. 13.

[0027] In FIGS. 9 and 10, when the electric motor 20 (see FIGS. 1 and 2) rotates, the rotation is transmitted to the cam plate 11 via the speed reduction mechanism 21, and the cam plate 11 rotates. As shown in FIGS. 10 and 11, the gear 21-1 closest to the cam plate 11 among the gears constituting the speed reduction mechanism 21 is integrated with the cam plate 11. When the cam plate 11 rotates, due to the inclination of the cam plate surface 11A (two inclinations arranged point-symmetrically), the position of the two cam plate contact bearings 12A near both ends of the cam follower rod 12 in the direction of the central axis C of the cam plate surface 11A with which they are in contact fluctuates, so the cam follower rod 12 moves in the direction of the central axis C. If the cam follower rod 12 moves in the direction of the central axis C, the shaft 1 (see FIGS. 1 and 2) moves via the shaft support portion 13 (base portion 13A) connected to the cam follower rod 12, and the valve opening degree of the flow rate adjustment valve 100 can be adjusted. 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 is controlled.

[0028] In the illustrated embodiment, using a rotating device such as the electric motor 20 as a power source, the rotational motion is converted into a linear motion by the cam plate 11 and the follower rod 12, so that the valve body 1AT (see FIGS. 4 to 7) reciprocates in the axial direction of the shaft 1 to adjust the valve opening degree. And if the electric motor 20 is used as the drive source, the valve opening degree can be directly controlled by controlling the electric motor 20. And according to the illustrated embodiment, since the rotational motion is not converted into a linear motion by a screw mechanism, 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 and damage of the screw thread engagement portion do not occur. Therefore, the durability of the flow rate adjustment valve is improved. Furthermore, by appropriately arranging bearings or rollers on the driven rod 12, the shaft support portion 13, and the speed 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. Therefore, it is not necessary to provide a large-sized actuator or an air valve as in the prior art. Then, by measuring the rotation amount of the electric motor 20, which is the drive source, or the rotation amount at a predetermined position in the speed reduction mechanism 21, the positions of the cam plate surface 11A and the cam follower 12 are specified, and by controlling the rotation amount of the electric motor 20 or the rotation amount at a predetermined position of the speed reduction mechanism 21, the position of the shaft 1 in the direction of the central axis C can be accurately controlled. Therefore, it is possible to accurately control the flow rate of the high-pressure gas in accordance with the required characteristics.

[0029] In FIG. 11 showing the back surface of the cam plate 11 (the surface opposite to the cam plate surface 11A), as described above, the gear 21-1 closest to the cam plate 11 side among the gears of the speed reduction mechanism 21 and the cam plate 11 are coupled by fitting a key 17 (not shown: see FIG. 2). And a thrust roller bearing 21A-1 (thrust roller bearing) is provided on the surface of the gear 21-1 opposite to the cam plate 11 (the lower surface in FIG. 11). By providing the 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. FIG. 12 shows a state in which the cam plate 11 and the gear 21-1 are integrated, and an inclined surface 11S and a stepped portion 11ST are formed on the cam plate surface 11A. The inclined surface 11S and the stepped portion 11ST will be described later with reference to FIG. 13. In FIG. 12, the illustration of the thrust roller bearing 21A-1 (see FIG. 11) provided on the gear 21-1 is omitted.

[0030] An inclination corresponding to the movement amount (displacement amount) of the shaft 1 (valve body 1AT, FIGS. 4 to 7) is formed on the surface 11A of the cam plate 11 (the cam plate surface: the upper surface in the illustrated example). In FIG. 13, in addition to the inclined surface 11S, a flat surface 11F is formed on the surface 11A of the cam plate 11. 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 circumferential ends of the inclined surface 11S-1, and flat surfaces 11F-21 and 11F-22 are formed adjacent to both circumferential ends of the inclined surface 11S-2. These flat surfaces are also point-symmetrical with respect to 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 two cam plate contact bearings 12A (see FIGS. 2, 9, and 10) arranged near both ends of the follower rod 12 with the same pressure.

[0031] In FIG. 13, the flat surface 11F is provided so that the rotation amount of the electric motor 20 is too large, the cam plate 11 rotates too much, and the valve opening degree to be adjusted does not deviate from the predetermined range. That is, because of the flat surface 11F, even if the electric motor 20 and the cam plate 11 rotate too much, the shaft 1 does not displace more than necessary, preventing the valve opening degree from becoming larger or smaller than a predetermined amount, and the opening and closing of the flow rate adjustment valve 100 are performed within a predetermined range. Thereby, damage to the valve seat 3AT and the shaft 1 can be prevented. As shown in FIG. 13, the circumferential distance of the flat surface 11F is shorter than that of the inclined surface 11S. Each of the inclined surfaces 11S-1 and 11S-2 projects gradually (in the direction of arrow SU) with respect to the flat surfaces 11F-11 and 11F-21 as it advances in the circumferential direction (arrow CL direction) from the same height as the respective flat surfaces 11F-11 and 11F-21 with respect to the moving direction of the shaft 1 (direction of arrow SU in FIG. 13). Then, the inclined surfaces 11S-1 and 11S-2 reach the flat surfaces 11F-12 and 11F-22 after passing the position where they project most in the direction of arrow SU. Step portions 11ST are formed at the boundaries between the flat surface 11F-12 and the flat surface 11F-21 and between the flat surface 11F-22 and the flat surface 11F-11, respectively. In FIG. 13, the height of the step portion in the direction of arrow SU is indicated by the symbol H. The height dimension H of the segment part 11ST (in the direction of arrow SU) is equal to the moving distance of the shaft center axis at the rapid release of the valve at the shaft tip 1A in Fig. 4, or the distance from the position of the shaft tip 1A in Fig. 4 (the valve closing position of the flow rate adjustment valve 100) to the position of the shaft tip 1A in Fig. 7 (the large flow rate region of the flow rate adjustment valve 100).

[0032] The mode of valve opening / closing control of the flow rate adjustment valve 100 by the rotation of the cam plate 11 will be described for the case of normal valve opening / closing and the case of rapid valve opening. In the case of normal valve opening / closing, the cam plate contact bearings 12A (see Figs. 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 are collectively referred to as the 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 side at the contact position (contact position) between the cam plate contact bearing 12A and the inclined surface 11S (the amount of protrusion in the direction of arrow SU in Fig. 13: protrusion amount), and the valve opening degree of the flow rate adjustment valve 100 is adjusted. When the "protrusion amount" increases (for example, when the contact position advances in the direction of arrow CL), the shaft 1 moves in the direction of closing the flow rate adjustment valve 100. When the "protrusion amount" decreases (for example, when the contact position advances in the direction opposite to arrow CL), the shaft 1 moves in the direction of opening the flow rate adjustment valve 100. When the "protrusion amount" increases as the contact position advances in the direction of arrow CL and the contact position reaches a position adjacent to the flat surface 11F-12 or 11F-22 (a position on the inclined surface 11S), the flow rate adjustment valve 100 is closed. Also, when the "protrusion amount" decreases as the contact position advances in the direction opposite to arrow CL and the contact position reaches a position adjacent to the flat surface 11F-11 or 11F-21 (a position on the inclined surface 11S), the flow rate adjustment valve 100 is opened.

[0033] When the cam plate 11 is rotated so that the contact position (abutting position) between the cam plate contact bearing 12A and the inclined surface 11S advances further in the direction of arrow CL from the closed position and moves beyond the stepped portion 11ST to the other flat surface 11F-11 or 11F-21, the shaft 1 moves in the direction of opening the flow rate adjustment valve 100. As a result, the flow rate adjustment valve 100 can be instantaneously fully opened from the closed state.

[0034] The opening and closing control of the flow rate adjustment valve 100 described above will be mainly described with reference to FIG. 14. 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 gear of the speed reduction mechanism 21 (FIGS. 1 and 2) may be measured. In step S2, based on the rotation amount of the electric motor 20 (or any gear of the speed reduction mechanism 21) measured in step S1, the valve opening degree of the flow rate adjustment valve 100 is calculated and determined. When calculating the valve opening degree of the flow rate adjustment valve 100, based on the rotation amount of the electric motor 20 or the like, the movement amount in the direction of the central axis C of the shaft 1 is calculated, and the valve opening degree of the flow rate adjustment valve 100 is calculated. Here, various parameters may be determined by calculation, but it is also possible to specify mathematical formulas or charts showing the mutual relationships in advance, obtain the mathematical formulas or charts, and determine the necessary parameters.

[0035] In the subsequent step S3, the valve opening degree of the flow rate adjustment valve 100 calculated and determined in step S2 is compared with the target value (valve opening degree in FIG. 3). The target value of the valve opening degree is, for example, a target value using the elapsed time as a parameter and has the characteristics shown in FIG. 3, but it may be determined by parameters other than the elapsed time. In step S4, in response to the comparison result in 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. As a result of the determination in step S4, if the valve opening degree of the flow rate adjustment valve 100 is smaller than the predetermined range of the target value, the process proceeds to step S5. If the valve opening degree is larger than the predetermined range of the target value, the process proceeds to step S6. And, when the valve opening degree of the flow rate adjustment valve 100 is within the predetermined range of the target value (step S4 is "Yes"), the process proceeds to step S7 without rotating the electric motor 20.

[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 minute rotation amount in the direction of increasing the valve opening degree of the flow rate adjustment valve 100. In step S6 (when the valve opening degree is larger than the predetermined range of the target value), the electric motor 20 is rotated by a predetermined minute rotation amount in the direction of decreasing the valve opening degree of the flow rate adjustment valve 100. In step S7, it is determined whether or not the filling using the system including the flow rate adjustment valve 100 has been completed. In step S7, if it is determined that "filling is completed" (step S7 is "Yes"), the control is terminated. If not ("filling is completed") (step S7 is "No"), the process returns to step S1 (the loop when step S7 is "No"). Although not shown in FIG. 14, in the case of rapid opening of the valve, it is determined whether or not the flow rate adjustment valve 100 is in the closed state, and it is determined whether or not rapid opening should be performed. When rapid opening should be performed, control is performed to rotate the electric motor 20 so that the contact position (contact position) of the cam contact bearing 12A and the inclined surface 11S moves from the flat surfaces 11F-12, 11F-22 over the step portion 11ST to the flat surfaces 11F-21, 11F-11.

[0037] The control device CU (control unit) that performs the opening / closing control of the flow rate adjustment valve 100 described above will be described with reference to FIG. 15. In FIG. 15, the 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 storage block B4. The valve opening degree determination block B1 acquires the detected value of the rotation amount from the electric motor rotation amount detection sensor 22 (measurement device) that measures the rotation amount of the electric motor 20 via the signal transmission line SL1. The valve opening degree determination block B1 acquires the "characteristic of the rotation amount of the electric motor 20 - valve opening degree of the flow rate adjustment valve 100" stored in the memory block B4 via the signal transmission line SL2. The relationship among the rotation amount of the electric motor 20, the protruding amount in the central axis direction of the contact position between the cam plate inclined surface 11S and the cam follower rod 12 (the moving amount in the central axis direction of the shaft 1 and the shaft tip 1A), and the valve opening degree of the flow rate adjustment valve can be determined in advance. Then, using the previously determined relationship, the valve opening degree of the flow rate adjustment valve can be calculated from the rotation amount of the electric motor 20 or the like.

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

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

[0040] Based on the comparison result by the comparison block B2, the control signal output block B3 has the function of outputting a control signal to the electric motor 20 (or the speed reduction mechanism 21) via the signal transmission line SL6 so that the valve opening degree of the flow rate adjustment valve 100 becomes the target value (or a numerical value within a predetermined range from the target value). As described in steps S5 and S6 of FIG. 14, the control signal is a "control signal for rotating the electric motor 20 in the direction in which the valve opening degree of the flow rate adjustment valve 100 increases" or a "control signal for rotating the electric motor 20 in the direction in which the valve opening degree of the flow rate adjustment valve 100 decreases". The storage block B4 has the function of pre-acquiring and storing information and data necessary for the opening / closing control of the flow rate adjustment valve 100 and providing them to each functional block as needed. The information and data stored in the storage block B4 are, for example, specification data regarding the components constituting the flow rate adjustment 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, speed reduction mechanism 21), the characteristic of the rotation amount of the electric motor 20 - the valve opening degree of the flow rate adjustment valve 100, the target value of the valve opening degree of the flow rate adjustment valve 100, and the like.

[0041] FIG. 16 shows a first modification of the illustrated embodiment. In the embodiment described with reference to FIGS. 1 to 15, for example, as shown in FIG. 10, bearings 12A for contacting the cam plate and bearings 12B for contacting the long holes are respectively provided at both ends of the cam follower rod 12 arranged to penetrate the shaft support portion 13. The bearing 12A for contacting the cam plate rolls on the surface 11A of the cam plate 11. And the bearing 12A for contacting the cam plate constitutes a rolling bearing. In contrast, in the first modification of FIG. 16, bearings 12B for contacting the long holes are provided at both ends of the cam follower rod 12-1 penetrating the shaft support portion 13, but no bearing for contacting the cam plate or rolling bearing is provided. In FIG. 16, the region radially inward of the bearing 12B for hole contact of the cam follower rod 12-1 contacts the surface 11A of the cam plate 11 and slides on the surface 11A. In other words, the region radially inward of the bearing 12B for hole contact of the cam follower rod 12-1 slides on the surface 11A of the cam plate 11. When the cam plate 11 rotates, the position of the cam follower rod 12-1 in the direction of the central axis C of the cam plate surface 11A with which it is in contact fluctuates, and the cam follower rod 12-1 moves in the direction of the central axis C, causing the shaft 1 (Figs. 1 and 2) to move, thereby enabling the valve opening degree of the flow rate adjustment valve 100 to be adjusted. The other configurations and operational effects of the first modification example in Fig. 16 are the same as those of the embodiments in Figs. 1 to 15.

[0042] In the first modification example of Fig. 16, the cam follower rod 12-1 is a cylindrical member with a constant radius and is in contact with the region from the inner diameter to the outer diameter of the cam plate 11. Due to the difference in the radius dimension from the rotation axis (central axis C) at the contact location, the contact area between the cam follower rod 12-1 and the cam plate surface 11A at the same rotational speed is larger near the outer diameter of the cam plate 11 compared to near the inner diameter. Therefore, the wear amount of the cam follower rod 12-1 and / or the cam plate surface 11A increases near the outer diameter of the cam plate 11. In the second modification example of Fig. 17, a relatively large-diameter region 12-2A and a relatively small-diameter region 12-2B are provided in the region radially inward of the bearing 12B of the cam follower rod 12-2, and a stepped portion is formed at the boundary between the large-diameter region 12-2A and the small-diameter region 12-2B. With such a configuration, only the large-diameter region 12-2A slides on the cam plate surface 11A. By appropriately setting the axial length of the large-diameter region 12-2A, the size of the portion where the cam follower rod 12-2 contacts the cam plate surface 11A can be adjusted. As a result, the difference in wear amount caused by the difference in radius dimension from the above-described central axis C can be reduced. This large-diameter region 12-2A may be constituted by a sliding bearing. The other configurations and operational effects in the second modification example of Fig. 17 are the same as those of the first modification example in Fig. 16.

[0043] Fig. 18 shows a third modification example of the illustrated embodiment. In the embodiments of FIGS. 1 to 15, the two cam contact bearings 12A contact the surface 11A of the cam plate 11, and the cam contact bearings 12A are respectively provided near both ends of the 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 the shaft support portion 13. The shaft support portion 13 extends in the central axis C direction (arrow C direction) at the center of the cam plate 11. On the other hand, in the third modification example of FIG. 18, the shaft support portion 13-1 extends in the central axis direction (arrow C direction) at a position offset radially outward from the center of the cam plate 11-1. Instead of the cam follower rod, a cam follower roller 12-3 (cam follower) rotatably supported is provided at the end of the shaft support portion 13-1 on the cam plate side, and moves on the cam plate surface 11A-1. The cam follower roller 12-3 is configured in a thin disk shape and constitutes a rolling bearing.

[0044] As shown in FIG. 18, about 1 / 2 of the cam plate surface 11A-1 is a flat surface 11F-1, and the remaining about 1 / 2 is an inclined surface 11S-1. A step portion 11ST-1 with a height H is formed at the boundary between the position where the inclined surface 11S-1 protrudes most in the central axis direction (arrow C direction) and the flat surface 11F-1. 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 FIGS. 10 and 13 because the portion in contact with the cam plate surface 11A-1 is a single cam follower roller 12-3. In FIG. 18, the rotation shaft (not shown) of the cam follower roller 12-3 is supported by each branch portion where the base portion 13A-1 of the shaft support portion 13-1 is bifurcated.

[0045] According to the third modification example of FIG. 18, when the cam plate 11-1 rotates, the shaft support portion 13 always moves up and down. Therefore, the shaft 1 only rotates around the axial direction and does not move in the axial direction (arrow C direction) (so-called "idling") does not occur. Therefore, it is possible not to provide an idling mechanism (a mechanism in which the long hole contact bearing 12B at the end of the cam follower rod 12 is inserted into the long hole 14A of the cam plate side casing 14: see FIG. 8) as in the embodiments of FIGS. 1 to 15. However, a pin (not shown in Fig. 18) extending radially outward is provided on the shaft support portion 13-1, and the pin is inserted into a long hole (not shown in Fig. 18) of a housing that covers the outside of the shaft support portion 13-1, so that the valve body 1AT and the valve seat 3AT (see Fig. 4) can be made to contact at the same position every time without rotating.

[0046] Also in Fig. 18, similar to the modified examples shown in Figs. 16 and 17, it is possible to provide a member (for example, a hemispherical member) that slides smoothly with the cam plate surface 11A instead of the cam follower roller 12-3, and the sliding member constitutes a sliding bearing. Fig. 18 shows only the cam plate 11-1, the shaft support portion 13-1, and the cam follower roller 12-3, but the other configurations, operations, and effects are the same as those described in Figs. 1 to 17.

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

Explanation of Reference Numerals

[0048] 1 ··· Shaft (valve rod) 1A ··· Shaft tip 2 ··· Main body portion 3 ··· Flow path 3A ··· Small-diameter portion of the flow path 3B ··· Large-diameter portion of the flow path 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 portion (roller or bearing) 13 ··· Shaft support portion (valve rod support portion) 20 ··· Electric motor (drive source) 21 ··· Speed reduction mechanism 22 ··· Measuring device 100 ··· Flow rate control valve CU ··· Control unit (control device) Lt ··· Dimension in which the shaft (small-diameter portion of the shaft) is inserted into the small-diameter portion of the flow path δ... gap

Claims

1. A cam plate having an inclination formed on its surface, A drive source that rotationally drives the cam plate via a speed reduction mechanism, A cam follower that is pressed against the surface of the cam plate and moves in the central axis direction of the flow rate adjustment valve due to the inclination of the surface of the cam plate, It has a valve rod support portion with one end connected to the cam follower and the other end connected to the valve rod, A flow rate adjustment valve characterized in that the flow rate varies depending on the dimension in which the valve rod is inserted into the small-diameter portion of the flow path.

2. A cam plate having an inclination formed on its surface, A drive source that rotationally drives the cam plate via a speed reduction mechanism, A cam follower that has a moving portion pressed against the surface of the cam plate and moves in the central axis direction of the flow rate adjustment valve due to the inclination of the surface of the cam plate, It has a valve rod support portion with one end connected to the cam follower and the other end connected to the valve rod, A flow rate adjustment valve characterized in that the flow rate varies depending on the dimension in which the valve rod is inserted into the small-diameter portion of the flow path.

3. The cam follower is entirely rod-shaped, and moving portions that are rotatably pressed against the surface of the cam plate are provided near both ends. It is a cam follower rod that is connected to one end of a valve rod support portion extending in the central axis direction at the central portion of the cam plate. The flow rate adjustment valve according to Claim 1.

4. The flow rate adjustment valve according to any one of Claims 2 and 3, wherein the moving portion is a rolling bearing.

5. The flow rate adjustment valve according to any one of Claims 2 and 3, wherein the moving portion is a sliding bearing.

6. The cam follower is constituted by a rotatable disk-shaped member, and the rotation axis of the disk-shaped member is supported at one end of a valve rod support portion extending in the central axis direction from a position eccentric radially outward with respect to the central portion of the cam plate. The flow rate adjustment valve according to Claim 1.

7. A flow rate adjustment valve according to any one of claims 1 to 3, comprising a measuring device for measuring the rotational speed of the output shaft of the drive source or the rotational speed of the gears constituting the speed reduction mechanism, and a control device for controlling the flow rate of the flow rate adjustment valve based on the measurement result of the measuring device.

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