JP5712053B2 - Valve actuator - Google Patents

Description

  The present invention relates to a valve actuator suitable for a valve used in a pipe line through which a high-pressure fluid flows, and more particularly, to a valve actuator suitable for a metal diaphragm valve actuator used in a piping system of a semiconductor manufacturing apparatus or the like.

Usually, a metal diaphragm valve used in a semiconductor manufacturing apparatus or the like has a metal diaphragm and a resin sheet packing, and an actuator is mounted on the upper side of the valve. This actuator has a stem that directly presses and moves the diaphragm pressing body disposed on the upper portion of the diaphragm, and presses or releases the diaphragm through the diaphragm pressing body by this stem, so that the diaphragm and the packing can be moved. It is the structure which opens and closes the flow path between.
Further, when the diaphragm valve is used for high-pressure fluid, it is necessary to increase the thrust during the diaphragm operation by the actuator in order to improve the sealing performance by the valve body. In this case, in general, an actuator for high pressure fluid includes a mechanism having a piston and a cylinder, and the thrust of the pressing body is increased by the piston / cylinder mechanism. Furthermore, in order to further increase the thrust of the piston, the cylinder structure may be provided in a plurality of stages such as two stages or three stages.

  On the other hand, a metal diaphragm valve is known in which a mechanism for increasing the thrust of an air cylinder is provided inside the actuator. As this type of diaphragm valve, for example, a metal diaphragm valve of Patent Document 1 is known. This diaphragm valve has a hard ball and a tapered pressing member, and acts on the hard ball using the pressing member as a wedge to increase the force for pressing the diaphragm.

  14 and 15 show a conventional valve actuator having an internal structure similar to that of the diaphragm valve disclosed in the literature 1. FIG. The actuator device 1 includes a ball body 2, a small-diameter needle 4 having a substantially conical inclined surface 3, a cylindrical member 6 having a mortar-shaped inclined surface portion 5, and a pressing member 8 that presses a diaphragm presser 7. Yes. The actuator device 1 is a so-called normally closed (NC) type in which the diaphragm valve body 12 in the diaphragm valve 11 is maintained in the closed state by the elastic force of the spring member 10 provided in the body portion 9 at normal times. It has become. When compressed air flows into the body portion 9 of the actuator device 1, the piston portion 13 provided in the body portion 9 rises from the state shown in FIG. ) To the state. When the needle 4 is raised, the ball body 2 moves in the direction of diameter reduction along the inclined surface 3 on the outer periphery of the needle, and the ball body 2 is also moved upward so as to be guided by the inclined surface portion 5 of the cylindrical member 6. It moves and the pressing by the pressing member 8 is released, and the diaphragm valve body 12 rises and enters the valve open state. At this time, the stroke (not shown) when the needle 4 moves up and down is about 5 to 6 times the stroke when the pressing member moves up and down.

  When the actuator device 1 and the diaphragm valve 11 are integrated together, the actuator is mounted with the ball member 2 between the actuator device 1 in which the tubular member 6 and the needle 4 are incorporated and the diaphragm valve 11. The device 1 and the diaphragm valve 11 are fixed by screwing. The positional relationship among the needle 4, the ball body 2, and the pressing member 8 is determined by adjusting the screwing position. Then, the screw connection between the actuator device 1 and the diaphragm valve 11 is adjusted to match the positional relationship, and the diaphragm valve body 12 is adjusted to the valve closing position, and the valve is integrated by the adjusting screw 14 provided for fixing. It is set to the state.

  Incidentally, high-pressure metal diaphragm valves for semiconductor manufacturing are desired to be reduced in size and cost in addition to being compatible with high-pressure fluids. In this case, by forming the cylinder shape of the actuator from a conventional square to a round shape, the cost may be reduced due to downsizing and material reduction.

Japanese Patent Publication No. 8-6828

  However, an actuator that directly moves the diaphragm pressing body with the stem and moves it up and down needs to increase the thrust by the diaphragm pressing body when flowing high pressure fluid. In this case, the cylinder has a multi-stage structure. When it is provided, it is difficult to reduce the size due to an increase in the dimension in the height direction, and the number of parts increases and the internal structure becomes complicated.

On the other hand, regarding the metal diaphragm valve of Patent Document 1 and the actuators of FIGS. 14 and 15, as shown in FIG. 14, a needle 4 that guides the ball body 2 is provided on the upper surface side of the pressing member 8. For this reason, the pressing member 8 becomes obstructive in the moving direction of the needle 4, and the length of the inclined surface 3 is limited by limiting the stroke when the needle 4 moves up and down. And it became difficult to ensure a large stroke of the needle 4, and the operating range of the ball body 2 by the inclined surface 3 was narrowed. Thereby, the stroke when the needle 4 moves up and down is limited to about 5 to 6 times the stroke when the pressing member 8 moves up and down, and the expansion of thrust by the piston portion 13 is limited to about 5 to 6 times. It was.
In order to increase the thrust, it is necessary to provide a plurality of cylinders. In this case, the entire size is increased and the number of parts is increased, leading to an increase in cost.

  Since the ball body 2 is arranged on the outer peripheral side of the inclined surface 3 of the tapered small-diameter needle 4 as described above, the number of ball bodies 2 that can be arranged is limited, for example, a small number of about 3 to 4 Only one can be placed. When the number of balls is small, the load applied to each ball body 2 when moving is large. In this case, the durability is poor due to increased friction and wear of the ball body 2 more vigorously, or depression of the cylindrical member 6 or the pressing member 8 due to a strong pressing force from the ball body 2. It was.

  When the actuator device 1 and the diaphragm valve 11 are assembled, the actuator device 1 and the diaphragm valve 11 are integrated by screwing, and the positional relationship among the needle 4, the ball body 2, and the pressing member 8 is adjusted by this screwing position. The valve closing position of the valve body 12 is adjusted. For this reason, the adjustment becomes troublesome, and an adjustment screw 14 for fixing to a predetermined adjustment position is required, and the number of parts is increased.

  The present invention has been developed in order to solve the above-mentioned problems. The object of the present invention is to increase the thrust force for operating the valve while reducing the overall size and reducing the number of parts. It can be applied to valves for high-pressure fluid with improved performance, and the load applied when moving is distributed to improve durability, the internal structure is simplified to reduce the number of parts, and assembly and adjustment to the valve is also possible An object of the present invention is to provide an easy valve actuator.

In order to achieve the above object, the invention according to claim 1 is an actuator for a valve that incorporates a thrust expansion mechanism that enlarges the thrust of the piston and closes the valve by an air-driven actuator that operates with the piston. A plurality of balls, which are moving members, are arranged on a disk surface provided on the upper part of the valve drive output shaft, and a piston is formed by hollowing out the fixed disk surface at the lower end of the shaft, which fixes these balls to the actuator body, and the inside of the piston. And a tapered surface portion that forms a conical tapered surface portion that spreads along the inner peripheral opening side of the disk, and a ball placed on the disk surface by the operation of the piston by moving between the disk surface and the fixed disk surface, the output to expand the thrust of the piston to the output shaft part, the a said shaft And screwed and fixed to the top of Chueta body is adjustably arranged actuator valve to adjustably disposed position of the fixed disk up and down the shaft by the screwing structure.

According to a second aspect of the present invention, there is provided a valve actuator including a thrust expansion mechanism for enlarging the thrust of the piston and closing the valve by an air-driven actuator operated by the piston, wherein the thrust expansion mechanism is a lower end of the shaft fixed to the actuator body. A roller cam, which is a moving member, is pivotally attached to the fixed member, and the first roller member provided at the upper end of the roller cam is hollowed out from the inside of the piston so as to expand along the inner peripheral opening side of the piston. The second roller member provided at the lower end of the roller cam is pressed against the disk surface of the valve shaft drive output shaft to expand the piston thrust to the output shaft. and while it outputs, to the shaft and fixed screwed to the top of the actuator body, adjusting the shaft up and down by the screwing structure Capable provided is adjustably disposed actuator valve position of the roller cam.

  The invention according to claim 3 is the valve actuator in which the output thrust of the thrust expanding mechanism for driving the valve is increased over the entire stroke from the valve opening to the valve closing.

  The invention according to claim 4 is the valve actuator in which any one of the tapered surface portion, the fixed disk surface and the disk surface is formed in a two-stage taper, arc portion or curved surface portion.

According to the first aspect of the present invention, a plurality of balls are arranged on the disk surface at the top of the output shaft portion, and these balls are formed into a fixed disk surface at the lower end of the shaft and a conical tapered surface on the inner peripheral opening side of the piston. For example, in a diaphragm valve, if it moves from valve opening to valve closing, the deadline thrust increases with the pressure receiving area of the diaphragm, but the thrust required for this deadline Therefore, it is possible to obtain an efficient output thrust matched to the high pressure, high thrust for valve closing and high stroke for large flow rate.
At this time, if the taper surface portion is a straight line, the enlargement ratio due to the ball at this straight portion is constant, and if it is a two-stage taper, it only changes to a two-stage enlargement ratio. Although the output thrust may decrease as the load decreases, the valve opens even when the spring load decreases by forming one of the tapered surface, fixed disk surface, or disk surface as a curved surface. It is possible to continuously increase the output thrust from the valve to the valve closing.
Without requiring a multi-stage cylinder, the overall size and internal structure can be simplified, the number of parts can be reduced, and the thrust for valve operation can be increased to improve the sealing performance of the valve. For this reason, it is suitable for a valve for high-pressure fluid, and the load is distributed by the tapered surface portion, so that the wear of the ball, piston, and fixed disk surface can be suppressed, and the durability can be improved. Since the piston, the output shaft, the ball, and the fixed disk surface at the lower end of the shaft can be integrated into the main body to be integrated into a unit, it is easy to attach to the valve and adjust it after installation. Furthermore, since the shaft is provided in a screwed structure, the position of the fixed disk can be adjusted by rotating the shaft up and down, so that the valve closing position can be adjusted according to variations in the sealing position of individual valves. . In this case, by attaching the shaft to the upper part of the actuator, the fixed disk can be tightened to the thrust expansion start position while rotating the shaft with a predetermined torque and easily adjusting the seal position.

According to the second aspect of the present invention, the first roller member of the roller cam pivotally attached to the fixed member abuts the taper surface portion movably, and the second roller member presses the disk surface of the output shaft portion to piston. Because it has a thrust expansion mechanism that expands the output thrust to the output shaft, the roller cam moves in a circular arc so that the taper surface of the piston inner surface is either straight or curved. The output thrust can be increased continuously from opening to closing. In this case, by obtaining an efficient output thrust, a high thrust for valve closing and a high stroke for a large flow rate can be achieved.
Without requiring multiple stages of cylinders, the overall size can be reduced, the internal structure can be simplified, the number of parts can be reduced, and the thrust for valve operation can be increased to improve the sealing performance of the valve. For this reason, it is suitable for a valve for high-pressure fluid, the load can be distributed by the tapered surface portion, durability can be improved, and assembly and adjustment to the valve can be facilitated. Furthermore, since the shaft is provided in a screwed structure, the roller cam can be adjusted by rotating the shaft up and down, so that the valve closing position can be adjusted according to variations in the sealing position of the individual valves. In this case, by attaching the shaft to the upper portion of the actuator, the roller cam can be tightened to the thrust expansion start position while the seal position is easily adjusted by rotating the shaft with a predetermined torque.

  According to the third aspect of the present invention, the output thrust of the thrust expansion mechanism is increased by the total stroke from the valve opening to the valve closing, so that the entire valve can be made compact without requiring a plurality of stages of cylinders. The output thrust required for the deadline can be reliably exhibited, and high sealing performance can be exhibited even in the case of high-pressure fluid. In the case of a thrust expansion mechanism with a roller cam, the expansion rate increases as the roller cam moves in a circular arc, and the valve cam moves toward the valve closing side. When operated to the side, the output thrust is further increased. Since the piston, the output shaft portion, the roller cam, and the disk surface of the output shaft portion can be integrated into the main body as a unit, it is easy to attach to the valve and adjust after the attachment.

  According to the fourth aspect of the present invention, any one of the tapered surface portion, the fixed disk, and the disk surface is provided on the two-stage taper, arc, or curved surface, and the thrust during piston operation is changed by changing the taper angle. The rate of increase of can be changed. In this case, by setting the opening side to a gentler taper angle than the back side, the output thrust is small on the valve opening side and the output thrust is increased near the valve closing side, so even if the same spring is used, high thrust and high stroke are achieved. Is obtained.

It is sectional drawing which showed 1st Embodiment of the actuator for valves of this invention. It is sectional drawing which showed the valve open state of the actuator for valves of FIG. It is the expanded sectional view which showed the principal part of FIG. (A) is a principal part expanded sectional view which showed the valve closed state. (B) is the principal part expanded sectional view which showed the valve open state. It is the graph which showed the characteristic of the actuator for valves. It is sectional drawing which showed 2nd Embodiment of the actuator for valves of this invention. It is sectional drawing which showed the valve open state of the actuator for valves of FIG. It is the expanded sectional view which showed the principal part of the actuator for valves. (A) is a principal part expanded sectional view which showed the valve closed state. (B) is the principal part expanded sectional view which showed the valve open state. It is the expanded sectional view which showed the valve body vicinity. (A) is the expanded sectional view which showed the valve closed state. (B) is the expanded sectional view which showed the valve open state. It is sectional drawing which showed 3rd Embodiment of the actuator for valves of this invention. FIG. 10 is a cross-sectional view showing a valve closed state of the valve actuator of FIG. 9. It is sectional drawing which showed 4th Embodiment of the actuator for valves of this invention. It is sectional drawing which showed the valve open state of the actuator for valves of FIG. It is sectional drawing which showed 5th Embodiment of the actuator for valves of this invention. It is sectional drawing which showed the conventional valve actuator. (A) is a principal part expanded sectional view of FIG. (B) is a principal part expanded sectional view which shows the state which valve closing operation | movement of (a) was.

  Embodiments of a valve actuator according to the present invention will be described below in detail with reference to the drawings. 1 and 2 show a first embodiment of a valve actuator according to the present invention. FIG. 1 shows a valve closed state, and FIG. 2 shows a valve open state. In FIG. 3, the principal part expanded sectional view in the open / close state of a valve is shown.

  In the figure, a valve actuator body (hereinafter referred to as actuator body) 20 includes a body 23 having a cylinder 21 and a base body 22 for covering the cylinder 21, and a tapered surface portion is provided in the body 23. And a thrust expanding mechanism 30 having a tapered disk-like surface 48 formed with 31, a fixed disk surface 50 formed of a tapered surface formed on the fixed disk 27, and a ball 28 as a moving member. Further, the actuator main body 20 is provided with a valve drive output shaft portion 26 and a disk 29, and the actuator main body 20 can drive an external valve (valve) 35.

  The tapered surface portion 31 is formed on the piston 25 provided in the actuator body 20. The tapered surface portion 31 is formed in a conical shape which is formed by hollowing out the piston inner peripheral surface 25a inside the piston 25 and extends along the inner peripheral opening side of the piston 25, and the piston inner peripheral surface 25a has this tapered surface shape. The tapered surface portion 48 including the portion 31 is formed. In the present embodiment, the tapered surface portion 31 has two different taper angles, which are a first tapered surface portion 31a on the opening side and a second tapered surface portion 31b following the first tapered surface portion 31a. It is provided on the stage. Although not shown, the taper angle of the first tapered surface portion 31a is gentler than the taper angle of the second tapered surface portion 31b.

  The tapered surface portion surface 48 is not limited to a taper, but may be formed in a two-stage taper, arc portion or curved surface portion. Furthermore, not only the tapered surface portion surface 48 but also the fixed disk surface 50 or a ball mounting portion 38 which is a disk surface described later can be formed in a two-stage taper or arc portion or curved surface portion. In any case, the taper angle can be set to an appropriate angle. In this case, as described above, it is desirable that the taper angle be such that the slope becomes gentler toward the operation direction.

  The piston 25 is formed in a substantially cylindrical shape, and this one piston is accommodated in the cylinder 21 so as to be reciprocally movable. O-rings 32 and 33 are attached to the inner and outer peripheral sides of the piston 25. A contact portion 34 is formed on the tip side of the piston 25, and this contact portion 34 can contact the base body 22 during operation.

  The valve drive output shaft portion 26 is disposed on an upper portion of the presser member 37, and the presser member 37 is provided to directly contact and drive the valve body 36 of the valve 35 attached to the actuator body 20. A disk 29 is provided on the opposite side of the output shaft portion 26 to the fixed disk 27, and a ball mounting portion 38 is formed on the surface of the disk 29. A shaft portion 39 is formed in the lower portion of the output shaft portion 26, and this shaft portion 39 is inserted into a mounting hole 40 formed in the base body 22, so that the entire output shaft portion 26 is connected to the base body 22. And can be moved up and down. A coil spring 41 is mounted between the output shaft portion 26 and the base body 22. The output shaft portion 26 is elastically biased upward in FIG. 1 by a coil spring 41. An O-ring 42 is attached to the outer periphery of the shaft portion 39, and the space between the shaft portion 39 and the base body 22 is sealed by the O-ring 42.

The fixed disk 27 is fixed to the upper portion of the actuator body 20 via the shaft 43. At that time, the fixed disk 27 is disposed so as to face the output shaft portion 26 by screwing a male screw portion 44 formed on the shaft 43 and a female screw portion 45 formed on the cylinder 21. With this screwing structure, the shaft 43 can be moved up and down to adjust its position, and the position of the fixed disk 27 can be adjusted. The valve closed position adjustment as described below by adjustment of the position of the fixed disk 27 becomes possible, there is no need to align by rotating the entire actuators body.

Inside the shaft 43, an inflow port 46 communicating with the outside of the actuator body 20 and between the piston 25 and the base body 22 is formed. Compressed air can be supplied into the cylinder 21 between the piston 25 and the base body 22 from the outside of the actuator body 20 through the inflow port 46 .

  The fixed disk 27 at the lower end of the shaft 43 fixed to the actuator body 20 is formed with the fixed disk surface 50 which faces the disk 29 and is inclined in the outer diameter direction. For example, the fixed disk surface 50 is formed at an angle of 30 ° with respect to the horizontal direction in FIG.

  The balls 28 are made of, for example, steel balls, and a plurality of balls 28 are arranged inside the thrust expanding mechanism 30. The number of balls 28 may be an appropriate number, but it is preferable to provide at least 3 balls, for example, about 8 to 12 balls. In this case, the output shaft portion 26 and the fixed disk 27 are in a stable state.

  As described above, the base body 22 is formed with the mounting hole 40 into which the shaft portion 39 of the output shaft portion 26 can be inserted. The mounting hole 40 can guide the output shaft portion 26 in the operation direction. A male screw portion 51 is formed on the cylinder side outer periphery of the base body 22, and this male screw portion 51 is screwed and joined to a female screw portion 52 formed in the cylinder 21 through a seal member 51 a so as to be hermetically sealed. A male screw 53 is formed on the valve mounting side of the base body 22, and the actuator body 20 is attached to and detached from the valve 35 via the male screw 53.

  The actuator body 20 is an air-driven actuator that operates with the piston 25 and has a built-in thrust expansion mechanism 30 that expands the thrust of the piston 25 and closes the valve 35. In the thrust expanding mechanism 30, the ball 28 that moves in contact with the tapered surface 48 during the stroke of the piston 25 is disposed.

  The thrust expansion mechanism 30 is provided inside the tapered surface portion surface 48. In this thrust expanding mechanism 30, a plurality of balls 28 are arranged on a ball mounting portion 38 on the surface of a disk 29 provided on the output shaft portion 26, and these balls 28 are fixed to a fixed disk surface 50 and a tapered surface portion. It is configured by being sandwiched between the surface 48. The cylinder 21 and the base body 22 are screwed in a sealed state and integrated as an actuator body 20. The piston 25 is attached so as to be movable up and down, and a spring 55 is disposed between the piston 25 and the cylinder 21. The piston 25 is ejected in a direction in which the pressing member 37 is pressed by the spring 55.

  When the piston 25 of the actuator body 20 is actuated, the ball 28 placed on the ball placing portion 38 on the surface of the disk 29 by this operation causes the ball placing portion 38, which is the disc surface, and the fixed disc surface 50 to Move between. By this movement, the thrust of the piston 25 can be output to the output shaft portion 26 by expanding. When the valve is driven by the thrust expanding mechanism 30 of the actuator body 20, the output thrust of the thrust expanding mechanism 30 may be increased over the entire stroke from the valve opening to the valve closing.

  The actuator body 20 has a structure in which the valve 35 is closed by a spring 55 attached to the back surface of a single piston 25, and the thrust of the spring 55 is expanded and output to the output shaft portion 26 by the thrust expansion mechanism 30. It is constructed as a normally closed type pneumatic actuator with a structure. The number of pistons is not limited to one, and a plurality of pistons can be stacked as will be described later.

  The valve 35 is a diaphragm valve having a general structure, and has, for example, the structure shown in FIG. The valve 35 includes a valve box 62 having a primary channel 60, a secondary channel 61, a valve body 36, a valve seat 64, a pressing member 37, and a bonnet 65. The valve body 36 is disposed at a predetermined position of the valve box 62, and a pressing member 37 for pressing is attached to the upper portion of the valve body 62 by a bonnet 65 so as to be movable up and down. A female screw 66 that can be screwed with the male screw 53 is formed on the connection side of the valve 35 with the actuator main body 20, and the female screw 66 and the male screw 53 are screwed to each other so that the thrust expanding mechanism 30 is provided inside. The actuator body 20 incorporating the valve and the valve 35 can be attached and detached with one touch.

  The presser member 37 moves up and down by the output in the axial direction of the output shaft portion 26 of the actuator body 20. Due to the vertical movement of the pressing member 37, the valve element 36 comes into contact with and separates from the valve seat 64, and the primary flow path 60 and the secondary flow path 61 can be opened and closed.

  In the above embodiment, the fixed disk surface 50 is formed on the fixed disk 27 side, but it is also possible to form a tapered surface (not shown) radially on the ball mounting portion 38 of the output shaft portion 26 from the center. In this way, a taper surface is formed on either or both of the fixed disk 27 and the disk 29, and the ball 28 is sandwiched between the taper surface and the taper surface portion surface 48 so that the thrust of the piston 25 is output. The output can be enlarged to 26. The same applies to second and third embodiments described later.

  1 and FIG. 3A, as described above, the actuator main body 20 is normally moved downward in the axial direction by the elastic force of the spring 55 disposed between the piston 25 and the cylinder 21. Is biased in the direction. At this time, the abutting portion 34 abuts on the base body 22 and the downward movement amount of the piston 25 is restricted, and an excessive force is prevented from being applied to the thrust expansion mechanism 30.

  When the piston 25 descends, a plurality of balls 28 are pushed inward (inner diameter direction) along the tapered surface portion 31 formed on the piston inner peripheral surface 25a, and along the fixed disk surface 50 of the fixed disk 27. Move. At this time, since the fixed disk 27 is fixed at a predetermined position in the actuator body 20 via the shaft 43, the ball 28 moves along the ball mounting portion 38 of the disk 29 toward the inner diameter side in the radial direction. The part 26 is pushed down.

  The axial movement component of the ball 28 is output from the output shaft portion 26 with the thrust increased through the disk 29. Since the fixed disk surface 50 and the ball 28 of the thrust expanding mechanism 30 are disposed inside the tapered surface portion 48 of the piston 25, the piston 25 and the output shaft portion 26 do not come into contact with each other. A long stroke and tapered surface portion 31 can be secured. By this mechanism, the stroke of the piston 25 can be lengthened. For example, the elastic force of the spring 55 is transmitted to the presser member 37 while expanding the thrust to about 10 to 20 times, and the presser member 37 moves the valve body 36 in the direction of the valve seat 64. The valve closed state can be maintained by pressing strongly. Therefore, high sealing performance suitable for high pressure fluid can be ensured.

In FIG. 3A, when the downward force F _1y from the piston 25 is transmitted to the contact C ₁ between the piston 25 and the ball 28 during the valve opening operation, the direction of the force is determined by the action of the tapered surface portion 31. The magnitude becomes a component force according to the law of component force, and acts on the ball 28 as a horizontal force F _1x . This force _{F 1x} is to be transferred from the ball 28 to the fixed disk 27 in contact _{C 2,} the force _{F 1x} and opposite force is exerted from the fixed disk 27 as a reaction force _F'1x. The reaction force F ′ _1x becomes a downward force F ′ _{1y at} the contact C ₂ according to the law of component force, and this force F ′ _1y is caused by the taper action of the tapered surface portion 31 and the fixed disk surface 50 in FIG. While increasing in the entire stroke from the valve opening to the valve closing in the direction of the arrow, the thrust is expanded to 10 to 20 times and output as an output thrust.

On the other hand, when compressed air is supplied between the piston 25 and the base body 22 through the inlet 46 of the shaft 43 from the outside, the piston 25 moves in the direction in which the spring 55 is compressed (upward in FIG. 1). For this reason, the ball 28 exerting a force that moves in the outer diameter direction by the fixed disk surface 50 moves in the outer diameter direction along the tapered surface portion surface 48, and the output shaft portion 26 has the elasticity of the coil spring 41. The valve body 36 and the pressing member 37 are moved upward by the pressure of the high-pressure fluid flowing in the flow path, and the valve is opened as shown in FIGS .

  Here, before the valve body 35 is opened and closed by the actuator body 20, it is necessary to match the valve closing position of the output shaft portion 26 (the lowest state in FIG. 1) with the valve closing position of the valve body 36. . At the time of alignment, the actuator body 20 and the valve 35 are fixed with the piston 25 in the lowest position. Next, the shaft 43 is rotated, and the fixed disc 27 provided at the tip of the shaft 43 is moved up and down to adjust the distance between the fixed disc 27 and the output shaft portion 26, and the valve body 36 is moved by the output shaft portion 26. Press in the closed state. At this time, the shaft 43 is tightened with a predetermined torque so that the spring 55 is resilient enough to maintain the valve closed state. Thereby, the positions of the output shaft portion 26 of the actuator body 20 and the valve body 36 can be matched.

  Thus, by rotating the shaft 43 screwed into the cylinder 21, the distance between the output shaft portion 26 and the fixed disk 27 can be easily adjusted, and the seal position of the valve body 36 can be adjusted accurately. In this case, as described above, the elastic force of the spring 55 can be expanded to a thrust of about 10 to 20 times and output from the output shaft portion 26. For example, when the thrust is increased 10 times, if the movement amount of the output shaft portion 26 is 0.1 mm and the frictional resistance of the thrust expansion mechanism 30 is 50%, the movement amount of the piston 25 is 2 mm. As described above, the amount of movement of the valve element 36 can be grasped with respect to the amount of movement of the shaft 43 from the enlargement ratio of the thrust. The position of the part 26 and the valve body 36 can be matched.

  For example, when the thrust by the actuator body 20 is increased 10 times, the moving amount of the valve seat deadline is 0.1 mm, and the moving amount of the piston 25 is 1 mm, and the valve is adjusted in accordance with the seal position of the valve seat. It is necessary to adjust the closing position. In that case, the seal position can be easily adjusted by adjusting the rotation of the shaft 43 with the piston 25 in the lowest position as described above, and tightening the fixed disk with a torque that generates about the piston thrust.

  4, changes in the diaphragm reaction force DF, the spring load SF, and the actuator output thrust AF with respect to the stroke (cylinder stroke) SL during the movement of the piston 25 during the valve closing operation of the actuator body 20 in FIG. Show. In the fully opened state of the valve, the actuator output thrust AF1 is obtained while the diaphragm reaction force DF1 and the spring load SF1 shown in FIG. In the fully closed state of the valve, the actuator output thrust AF2 is obtained while the diaphragm reaction force DF2 and the spring load SF2 shown in FIG.

  With respect to the diaphragm reaction force DF, the diaphragm valve body 36 is formed in a so-called dome shape, and receives the pressure at this dome portion to transmit the thrust, so that the diaphragm reaction force DF1 when the valve of FIG. Become. When operated from the valve open state to the valve closed state, the pressure receiving area from the fluid gradually increases with the deformation of the valve body 36. When the valve shown in FIG. 3 (a) is closed, the pressure receiving area received by the valve body 36 from the fluid is maximized, and the diaphragm reaction force DF2 required to close the valve body 36 is maximized.

  As for the spring load SF, the spring 55 is compressed by the piston 25 in the valve open state and becomes large, and the spring load SF1 becomes maximum when the valve is fully opened. When the valve is operated from the valve open state to the valve closed state, the spring load SF is reduced, thereby reducing transmission efficiency and weakening the force for operating the valve body 36 in the valve closing direction. When fully closed in FIG. 8, the spring load SF2 in the cylinder stroke SL is minimum.

Since the thrust expansion mechanism 30 of the valve actuator of the present invention increases the output thrust AF in the valve closing direction in the full stroke during the valve stroke L when the valve element 36 operates from full open to full close. The valve stroke L is increased on the fully open side where the spring load SF1 is maximum, and the maximum output thrust AF2 can be output on the fully closed side.
Thus, by efficiently expanding and transmitting the thrust, even when the actuator body 20 is downsized, it is possible to cope with a high thrust of the high-pressure valve and a high stroke for a large flow rate. In this case, for example, even when the actuator body is provided with a size of about 70% of a general actuator diameter, it is possible to cope with a pressure / flow rate equivalent to that of a general actuator.

  As described above, the valve actuator of the present invention forms the tapered surface portion surface 48 formed with the conical tapered surface portion 31 that extends along the inner peripheral opening side of the piston 25 provided in the main body 20. The moving member 28 that moves in contact with the tapered surface portion 31 during the stroke of the piston 25 is disposed, and the output thrust for closing the valve 35 is opened via the thrust expanding mechanism 30 having the moving member 28. Therefore, it is possible to cope with high-pressure fluid while reducing the size and reducing the size without providing a multi-stage cylinder structure.

  In this case, the thrust expanding mechanism 30 causes the ball 28 to move between the tapered surface portion surface 48 and the fixed disk surface 50 by the operation of the piston 25 and expands the thrust of the piston 25 to the output shaft portion 26 and outputs it. Since it is a mechanism, the stroke of the piston 25 and the tapered surface portion surface 48 can be lengthened. For this reason, for example, the output thrust from the output shaft portion 26 can be increased as compared with the case where the piston 25 is needle-shaped, and the thrust can be increased to 10 to 20 times that of a higher pressure fluid. Furthermore, the number of parts can be reduced by simplifying the cylinder structure. In addition, by adjusting the angles of the tapered surface portion surface 48 and the fixed disk surface 50, it becomes possible to arbitrarily set the magnification of the output thrust.

  By providing the taper surface portion surface 48 in a two-stage taper, the angle of the taper surface portion surface 48 can be changed to adjust the rate of increase in thrust during piston operation. By this adjustment, for example, the amount of movement of the output shaft can be reduced in the vicinity of the valve closed state to adjust the fine flow rate, and when the valve is in the valve open state, the amount of movement of the output shaft can be increased to open the valve. The speed can be increased to quickly switch from valve closing to valve opening.

  Since the fixed disk surface 50 and the balls 28 are disposed inside the tapered surface portion surface 48, the number of the balls 28 can be increased, and the force from the piston 25 is dispersed by increasing the number of the balls 28. Thus, it can be transmitted to the output shaft portion 26. Therefore, the consumption of the ball 28 can be suppressed, the output shaft portion 26 can be prevented from being depressed or damaged, and the durability can be improved.

  When configuring the actuator body 20, the thrust expanding mechanism 30 having the piston 25, the output shaft portion 26, the fixed disk 27, and the ball 28 can be integrated with the cylinder 21 and the base body 22. For this reason, the actuator main body 20 is provided separately from the valve 35 in advance, and the incorporation with the valve 35 and the adjustment of the valve body 36 can be easily performed.

  5 and 6 show a second embodiment of the valve actuator of the present invention. In the following embodiments, the same parts as those in the above-described embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  The actuator in this embodiment is similar to the actuator body 20 of the above-described embodiment, and the diaphragm valve body 36 is closed by the load of the spring 55 while the thrust is expanded by the thrust expansion mechanism 30 having the ball 28 as shown in FIG. This is a pneumatically operated valve actuator having a normally closed type mechanism that is operated in a state and is operated in the sealed main body 90 to the valve open state of FIG.

  As shown in FIGS. 7A and 7B, in the actuator main body 90, the tapered surface portion 91 of the tapered surface portion 48 of the piston 93 is formed by an arc portion. When the ball 28 comes into contact with the arc portion 91, the piston 93 can be operated smoothly. Further, since the contact area between the ball 28 and the arc portion 91 becomes long, the piston 93 can be operated gently to finely adjust the valve opening.

Furthermore, the circular arc portion 91 has two different taper angles including a first circular arc portion 91a on the opening side and a second circular arc portion 91b following the first circular arc portion 91a. The taper angle is gentler on the back side than on the opening side. That is, in FIG. 7A, the taper angle θ _{1 of} the second arc portion 91 b <the taper angle θ ₂ of the first arc portion 91 a. It has become. Thus, as in the case of the first embodiment, the angle of the arc portion 91 can be changed to adjust the rate of increase in thrust when the piston 93 is actuated.

  Further, the actuator main body 90 in this embodiment is provided in a three-stage piston structure in which a piston 96 and a cylinder portion 94 having different shapes are provided above the piston 93. A branch port 95 branched from the inlet 46 is formed inside the shaft 43, and compressed air is supplied between the piston 93 and the cylinder portion 94 via the branch port 95.

  When the piston is configured in a plurality of stages, it is possible to make the size in the width direction compact by reducing the cylinder outer diameter while increasing the thrust as compared with the case of one piston. This space saving enables integration with a small footprint even in a narrow space. In the case where the pistons are provided in three or more stages, the piston 96 and the cylinder part 94 having the same shape can be used together and can be easily assembled while preventing them from increasing in number of parts by stacking them up and down.

9 and 10 show a third embodiment of the valve actuator of the present invention.
The actuator body 70 has a structure in which a spring 55 is disposed between one piston 71 and the fixed disk 27 to supply air pressure from the back surface of the piston 71 to close the valve 35. As a result, the actuator body 70 is a normally open type in which the thrust of the piston 71 is expanded and output to the output shaft portion 26 by the thrust expanding mechanism 30. Although not shown, even in the normally open type, a plurality of stages of pistons can be overlapped as in the case of normally closed.

  Inside the shaft 21, an air flow path 72 is formed to communicate between the outside of the actuator body 70, the piston 25, and the cylinder 21 constituting the body 23, and the piston is externally connected via the air flow path 72. It is possible to supply compressed air between 71 and the cylinder 21.

When compressed air is supplied from the outside between the piston 71 and the cylinder 21, the piston 71 operates in a direction (downward direction in FIG. 9) to compress the spring 55 against the elastic force of the spring 55. Is moved in the inner diameter direction along the tapered surface portion 48 having the tapered surface portion 31, and the output shaft portion 26 moves downward against the elastic force of the coil spring 41 so that the output shaft portion is moved. 26 moves downward, and the output shaft portion 26 presses the pressing member 37 downward, and the valve is closed as shown in FIG .

  11 and 12 show a fourth embodiment of the valve actuator of the present invention. The actuator main body 100 of this embodiment includes a thrust expanding mechanism 101 having two roller cams 102 for expanding the thrust. Each of the roller cams 102 and 102 is pivotally attached to a fixing member 105 fixed in the cylinder 21 at the lower end of the shaft 43 fixed to the main body 100. The fixing member 105 is attached to the distal end side of the shaft 43 with a nut 107, and after the attachment, the fixing member 105 is disposed at a predetermined position in the cylinder 21.

  The shaft 43 is fixed to the upper part of the actuator body 100 by screwing in the same manner as in the above embodiment. With this screwing structure, the shaft 43 is provided so as to be adjustable up and down, and the vertical position of the roller cam 102 can be adjusted.

  A first roller member 103 is provided at the upper end of the roller cam 102, and the first roller member 103 is disposed in a state in which the first roller member 103 is movably in contact with the tapered surface portion 97 that forms the tapered surface portion 91. Yes. The tapered surface portion 91 is formed in a conical shape that is hollowed out along the inner peripheral opening side of the piston 108 by hollowing out the piston inner peripheral surface 108a inside the piston 108. The tapered inner surface 108a has a tapered surface shape. A tapered surface portion surface 97 having a portion 91 is formed.

On the other hand, the second roller member 104 is provided at the lower end of the roller cam 10 2. When thrust is transmitted from the piston 108, the roller cam 102 is rotated about the shaft-attached portion 106 by the first roller 103 in contact with the tapered surface portion surface 97, and the rotation of the roller cam 102 causes the second roller member 102 to rotate. 104 is pressed against the disk 29 of the output shaft portion 26, and the thrust of the piston 108 is enlarged and output to the output shaft portion 26.

  Two springs 109 and 110 are provided between the piston 108 and the cylinder 21, and the spring constants of these springs 109 and 110 are set smaller than the spring constant of the spring 55 of the second embodiment, for example. It has been. In this case, a decrease in the load of the spring when the valve is opened to closed can be suppressed.

  The actuator main body 100 can be attached to the valve 35 in the same manner as the thrust expansion device 30 described above. At the time of attachment to the valve 35, the male screw 53 and the female screw 66 are screwed together so that the actuator body 100 incorporating the thrust expansion mechanism 101 and the valve 35 can be attached and detached with one touch.

  In the actuator main body 100 of FIG. 11, the piston 108 is normally biased downward by the elastic force of the spring 55. As the piston 108 descends, the roller 103 on the upper side rotates along the tapered surface portion 97, and the roller cam 102 rotates around the shaft attachment portion 106. At this time, since the roller cam 102 rotates in a direction to stand up around the shaft attachment portion 106, the output shaft portion 26 is pushed down by the roller 104 by pushing the disk 29 downward while the lower roller 104 rotates. . At that time, the thrust from the piston 108 is transmitted while expanding. In the case of the thrust expansion mechanism 101 using the roller cam 102, the power conversion efficiency can be increased, and sufficient thrust can be obtained by one piston shown in the figure. Further, at this time, as in the case where the ball is a moving member, the piston can be made more compact by further increasing the thrust by configuring the pistons in a plurality of stages.

In FIG. 12, when compressed air is supplied between the piston 108 and the base body 22 from the inlet 46, the piston 108 rises while compressing the springs 109 and 110, and accordingly, the upper roller 103 is tapered. The roller cam 102 rotates in a direction tilting to the left and right around the shaft attachment portion 106 while rotating with respect to the surface 97. As a result, the position of the lower roller 104 moves upward as compared with the case of FIG. 11, and along with this movement, the output shaft portion 26 moves upward due to the elastic force of the coil spring 41 to be in the valve open state. .
As described above, the thrust enlarging mechanism 101 can be provided using the roller cam 102 instead of the ball 28, and the thrust enlarging mechanism can be provided in a structure other than these. In the case of this actuator body 100 as well, as in the case of the actuator body 20 described above, the output thrust of the thrust expanding mechanism 101 that drives the valve can be increased over the entire stroke from valve opening to valve closing.

  Further, although the actuator body 100 is a normally closed type, it can be configured as a normally open type as in the case of a thrust expansion mechanism using the ball 28. In any case, the output thrust in the valve closing direction of the valve element 36 from the fully open position to the fully closed position can be increased in a state that is always larger than the reaction force due to the fluid pressure.

FIG. 13 shows a fifth embodiment of the valve actuator of the present invention.
This actuator body 80 has an actuator structure having a single-stage cylinder structure that does not have a thrust expanding mechanism inside, and uses the same base body 22 as the actuator bodies 20 and 70 described above in common.
As described above, since the actuator body 20, 70, 80 having different internal structures can be configured by using the base body 22 in common, the actuators having different internal structures and sizes can be used depending on the application and use location of the valve. The added value of the product can be increased. Furthermore, for example, it is possible to attach a valve having a structure that operates by vertical movement other than a metal diaphragm valve, and in any case, it is simple by screwing the male screw of the base body and the female screw of the valve. It can provide in the structure which can be attached or detached to.

20 Actuator body 25 Piston 26 Output shaft 27 Fixed disk 28 Ball (moving member)
29 Disc 30 Thrust expansion mechanism 31 Tapered surface portion 35 Valve (valve)
43 Shaft 48, 97 Tapered surface portion surface 50 Tapered surface 55 Spring 102 Roller cam 103 First roller member 104 Second roller member 105 Fixing member

Claims (4)

In a valve actuator having a built-in thrust expansion mechanism that closes the valve by enlarging the thrust of the piston with an air-driven actuator that operates with the piston, the thrust expansion mechanism is located on the disk surface provided above the output shaft for valve drive. A plurality of balls, which are moving members, are arranged on the actuator body, and a conical taper that extends along the inner peripheral opening side of the piston by hollowing out the fixed disk surface at the lower end of the shaft that fixes these balls to the actuator body and the inside of the piston The ball is placed between the disk surface and the fixed disk surface by the operation of the piston. by moving, and outputs the enlarged thrust of the piston to the output shaft part, the actuator the said shaft Of screwed and fixed to the upper, valve actuator, characterized in that provided in adjustable position of the fixed disc is provided adjustably for said shaft up and down by the screwing structure. In a valve actuator that incorporates a thrust expansion mechanism that closes the valve by enlarging the thrust of the piston with an air driven actuator that operates with the piston, the thrust expansion mechanism is a moving member on a fixed member at the lower end of the shaft fixed to the actuator body. Tapered surface formed by attaching a roller cam to the shaft and forming a conical tapered surface portion that is formed by hollowing out the inside of the piston and extending along the inner peripheral opening side of the piston. movably contact with the stepped surface, and outputs the enlarged thrust of the piston is pressed against the disk surface of the second roller member the valve shaft driving output shaft portion which is provided at the lower end of the roller cam to the output shaft part The shaft is screwed and fixed to the upper portion of the actuator body, and the shaft can be adjusted up and down by this screwing structure. Valve actuator, characterized in that provided in adjustable position of the roller cam Te.   3. The valve actuator according to claim 1, wherein an output thrust of the thrust expanding mechanism that drives the valve is increased over the entire stroke from the valve opening toward the valve closing. 4.   4. The valve actuator according to claim 1, wherein any one of the tapered surface portion surface, the fixed disk surface, and the disk surface is formed in a two-stage taper, arc portion, or curved surface portion. 5.

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