Actuator, opening / closing valve mechanism, and fluid control device

Abstract

The purpose of the present invention is to provide an actuator having excellent responsiveness compared to an actuator in which a plurality of assemblies to be disposed inside a casing are stacked alone in an axial direction, and an open / close valve mechanism.　An actuator 10 of the present invention comprises: a casing 20, a shaft body 30 disposed inside the casing 20, and formed with a long hole LH and a plurality of exhaust holes EH; a plurality of assemblies 40 arranged to correspond to the plurality of exhaust holes EH, respectively, each assembly 40 having a partition body 42 and a piston body 44, and forming a closed space with each partition body 42, each partition body 42 abutting an inner circumferential surface of the casing 20 over the entire circumference while allowing penetration of the shaft body 30, each piston body 44 allowing the shaft body 30 to penetrate therethrough; a biasing body 50 for biasing a piston body 44H from an upper end side toward a lower end side; and a push rod 60 connected to an opposite side of the shaft body 30 with respect to an opening of the shaft body 30. An open / close valve mechanism 110 comprises the actuator 10, a valve body 70, and a body 80, and has a function of controlling communication and shut-off of fluid.

Description

[Technical Field]

[0001] This application claims priority based on Japanese Patent Application No. 2022-097678, filed June 16, 2022. The entirety of this Japanese application is incorporated herein by reference.

[0002] The present invention relates to an actuator, an on-off valve mechanism, and a fluid control device. [Background technology]

[0003] As shown in FIG. 2, FIG. 4, etc., Patent Document 1 discloses a multi-stage piston actuator including a cylinder body, multiple piston bodies, multiple partitions, a coil spring, and a push rod, and an on-off valve mechanism having this multi-stage piston actuator.

[0004] Each of the multiple piston bodies is combined with a partition that fits into the cylinder body, forming a pressure chamber between them. Each piston body has a pressure plate portion, a shaft rod extending from the pressure plate portion in one thickness direction and having an axial air passage communicating with the pressure chamber, and a sliding guide tubular portion extending in the other thickness direction. Each partition has a bottom plate portion with a through hole formed therein to accommodate the shaft rod of an adjacent piston body, a large-diameter outermost tubular portion extending from the bottom plate portion in one thickness direction and fitting into the cylinder body, and a sliding guide tubular portion extending in one thickness direction and slidably fitting into the sliding guide tubular portion of the piston body. Together with each piston, each partition constitutes a unit that is arranged overlapping along the axial direction of the cylinder body. Coil springs are positioned in compression between the multiple units and one end wall of the cylinder body. Push rods are positioned at the other axial ends of the multiple units.

[0005] With this multi-stage piston actuator having the above-described configuration, when compressed air is supplied from outside to the inside of the cylinder body, pressure that resists the spring pressure from the coil spring is exerted on each pressure chamber, causing the shafts of each piston body to come into mechanical contact with each other, exerting an output on the push rod. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6170635 Summary of the Invention [Problem to be solved by the invention]

[0007] In the multi-stage piston actuator disclosed in Patent Document 1, multiple units, each consisting of a piston body and a partition, are stacked axially and biased by a coil spring at their upper ends and disposed inside a casing. In this multi-stage piston actuator, immediately after a driving fluid supplied from the outside to the casing is sent into the pressure chamber of a unit, the piston body of another unit adjacent to the unit downstream in the driving fluid flow direction may separate axially from the piston body of the first unit. As a result, the piston bodies move sequentially, starting with the topmost one, toward the upstream side in the driving fluid flow direction. As a result, compared to when the piston bodies move as a single unit, it takes longer for the bottommost piston body to rise and the valve to open. As a result, the multi-stage piston actuator disclosed in Patent Document 1 has a long time lag between receiving an open command and actually opening the valve, adversely affecting responsiveness.

[0008] One of the objects of the present invention is to provide an actuator and an opening / closing valve mechanism including this actuator that has superior responsiveness compared to an actuator in which multiple assemblies placed inside a casing are stacked and arranged in the axial direction. [Means for solving the problem]

[0009] The actuator of the first aspect comprises: a casing having an introduction hole formed at one end thereof for introducing a driving fluid from the outside; a shaft disposed within the casing along the axial direction of the casing, the shaft having an elongated hole that opens in the same direction as the inlet hole and extends along the axial direction, and a plurality of exhaust holes that communicate with the elongated hole and are arranged at predetermined intervals along the axial direction, the shaft introducing the driving fluid from the inlet hole through the opening of the elongated hole and discharging it from the plurality of exhaust holes; a partition body including a disk body having a first through hole formed in the center and an outer cylindrical body standing on the periphery of the disk body and abutting against the inner peripheral surface of the casing; a piston body having a rod-shaped cylindrical body with a second through hole formed at the center and inserted into the first through hole, the piston body being arranged at a plurality of positions inside the casing corresponding to the plurality of exhaust holes; a biasing body disposed inside the casing; Equipped with Each partition body in the plurality of assemblies abuts against an adjacent partition body in the axial direction at the end surface of the outer cylindrical body and the disk body, and each piston body abuts against an adjacent piston body in the axial direction at the rod-shaped cylindrical bodies, Each piston body passes through the second through-hole so as to be able to abut against the shaft body, and together with each partition body, forms a closed space communicating with each exhaust hole at each position of the plurality of exhaust holes; Either the piston body arranged on the most one end side or the most other end side is connected to the shaft body, The biasing member biases the piston member connected to the shaft member in a direction against the pressure of the driving fluid.

[0010] The actuator of the second aspect is 1. The actuator of the first aspect, an internal thread is formed on an inner peripheral surface of the other end of the second through hole in the piston body on the one end side, A male thread is formed on the outer peripheral surface of one end of the shaft body, The first end side piston body is connected to the shaft body by fastening the female thread and the male thread together.

[0011] The actuator of the third aspect is The actuator of the first or second aspect, a portion of the shaft body on the other end side in the axial direction includes a cylindrical body having an annular flat surface facing the one end side in the axial direction and an outer peripheral surface having the same outer diameter as the rod-shaped cylindrical body, The cylindrical body supports the piston body that is located at the other end of the axial direction among all the piston bodies that constitute the multiple assemblies on the annular plane, and forms the closed space together with the assembly that is located at the other end of the axial direction among the multiple assemblies.

[0012] The actuator of the fourth aspect is 10. The actuator of the third aspect, The other axial end portion has a connecting portion.

[0013] The opening and closing valve mechanism of the first aspect is The actuator has any one of the first to fifth aspects.

[0014] The opening and closing valve mechanism of the second aspect is The on-off valve mechanism of the first aspect, It has a bellows structure connected to the connecting portion.

[0015] One aspect of the fluid control device comprises: The valve mechanism includes the valve mechanism of the first or second aspect. [Effects of the Invention]

[0016] The actuators of the first to fourth embodiments, the on-off valve mechanisms having the actuators, and the fluid control devices including the on-off valve mechanisms have actuators of the above configurations, and therefore are actuators, on-off valve mechanisms, and fluid control devices that have superior responsiveness compared to actuators in which multiple assemblies arranged inside a casing are stacked and arranged in the axial direction using only these assemblies. [Brief explanation of the drawings]

[0017] [Figure 1]FIG. 1 is a diagram of an actuator for driving a normally closed valve to open in an embodiment of the present invention (hereinafter referred to as the present embodiment), and is a vertical cross-sectional view in a state where no driving fluid has been introduced into the casing (at zero stroke). [Figure 2] FIG. 2 is an enlarged view of the area surrounded by dashed line A in FIG. [Figure 3A] FIG. 10 is a top view of a partition body included in each of a plurality of assemblies of the actuator of this embodiment. [Figure 3B] FIG. 3B is a longitudinal cross-sectional view of the partition body of FIG. 3A taken along a cutting line (IIIB) including its axis. [Figure 4A] FIG. 10 is a bottom view of a piston body included in each of a plurality of assemblies of the actuator of the present embodiment. [Figure 4B] FIG. 4B is a longitudinal cross-sectional view of the piston body of FIG. 4A taken along a cutting line (IVB) including its axis. [Figure 5] FIG. 1 is a diagram of the actuator of this embodiment, showing a longitudinal cross section of the actuator in a state where a driving fluid is introduced from the outside into the casing (at full stroke). [Figure 6] FIG. 6 is an enlarged view of the portion surrounded by the dashed line B in FIG. 5. [Figure 7] FIG. 2 is a vertical cross-sectional view of an opening / closing valve mechanism including an actuator according to the present embodiment. [Figure 8] 1 is an external perspective view of a fluid control device including an on-off valve mechanism according to an embodiment of the present invention. [Figure 9] 10A and 10B are diagrams of two adjacent assemblies of a comparative actuator, showing longitudinal cross sections of the two piston bodies before and after the introduction of a driving fluid into the interior of the casing. DETAILED DESCRIPTION OF THE INVENTION

[0018] Overview The present embodiment and several modified examples thereof will be described below. First, the present embodiment will be described. Then, several modified examples will be described. Please note that in this specification, components having equivalent functions are assigned the same reference numerals in each drawing referred to in different embodiments. For convenience, the upper direction of the drawing will be referred to as the upper end side, and the lower direction will be referred to as the lower end side.

[0019] <<Present Embodiment>> The functions, configuration, operation, and effects of this embodiment will be described below in the order of description with reference to the drawings.

[0020] <Function and Configuration of the Actuator of the Present Embodiment> FIG. 1 is a diagram of an actuator 10 according to this embodiment, showing a longitudinal cross-sectional view of a state in which no driving fluid is introduced into the casing 20 (at zero stroke). FIG. 2 is an enlarged view of the portion surrounded by dashed line A in FIG. 1. FIG. 3A is a top view of a partition body 42 included in each of the multiple assemblies 40 of the actuator 10, and FIG. 3B is a longitudinal cross-sectional view of the partition body 42 of FIG. 3A taken along a section line (IIIB) including its axis. FIG. 4A is a bottom view of a piston body 44 included in each of the multiple assemblies 40B-F other than the assembly 40A located at the uppermost end in the axial direction of the casing 20, and FIG. 4B is a longitudinal cross-sectional view of the piston body 44 of FIG. 4A taken along a section line (IVB) including its axis. FIG. 5 is a diagram of the actuator 10, showing a longitudinal cross-sectional view of a state in which a driving fluid is introduced into the casing 20 from the outside (at full stroke). FIG. 6 is an enlarged view of the portion surrounded by dashed line B in FIG. 5.

[0021] 1, 5, etc., the actuator 10 of this embodiment includes a casing 20, a shaft 30, a plurality of assemblies 40, a coil spring 50 (an example of a biasing body), and a push rod 60. The actuator 10 of this embodiment has a function of moving the push rod 60 in response to the introduction of a driving fluid from the outside, thereby moving the shaft 30 from a zero stroke position (see FIG. 1) to a full stroke position (see FIG. 5). The actuator 10 will be described below by dividing it into each of the above-mentioned components.

[0022] [Casing] As shown in FIGS. 1 and 5, the casing 20 of this embodiment is, for example, a cylindrical part.

[0023] As an example, the casing 20 has a shape that is approximately symmetrical about its own axis (denoted by the symbol O in the drawings). The casing 20 has a through-hole formed therein that penetrates from its upper end (the symbol + in the drawings indicates the upper end in the axial direction) to its lower end (the symbol - in the drawings indicates the lower end in the axial direction). The casing 20 in which the through-hole is formed has a shape that results in a structure described below in order to arrange the shaft 30, the multiple assemblies 40, the coil spring 50, and the push rod 60 in a predetermined positional relationship inside the casing.

[0024] Here, for convenience, if the casing 20 is divided into an upper casing section 22, a lower casing section 24, and a middle casing section 26 connecting the upper casing section 22 and the lower casing section 24, the upper casing section 22, the middle casing section 26, and the lower casing section 24 each have a structure to perform the following functions.

[0025] 1 and 5, an introduction hole 22A for introducing a driving fluid into the casing 20 is formed on the upper end side of the casing upper part 22. In addition, a recess for accommodating a coil spring 50 (described later) is formed on the lower end side of the casing upper part 22.

[0026] The casing lower part 24 is configured so that a portion of the shaft 30 can be slidably inserted therethrough, so that the push rod 60 can be disposed therein, and so that the casing lower part 24 abuts against a partition body 42F of the assembly 40F that is disposed axially lowest in the axial direction among the multiple assemblies 40. Here, the portion that abuts against the partition body 42F is an annular flat surface 24A. In addition, a male thread for threadably engaging with a body 80 (described later) is formed on the outer circumferential surface below the through hole 24B.

[0027] The casing intermediate portion 26 is configured so that a portion of the shaft body 30 and a plurality of assemblies 40 are disposed therein.

[0028] [Shaft] As shown in Figures 1 and 5, the shaft body 30 of this embodiment is disposed inside the casing 20 along the axial direction of the casing 20. The shaft body 30 has a central elongated hole LH extending axially from the upper end to the lower end. The peripheral wall of the shaft body 30 also has a plurality of exhaust holes EH that communicate with the elongated holes LH and are arranged at set intervals along the axial direction. Here, in this embodiment, the number of exhaust holes EH is, for example, six, the same as the number of assemblies 40 described below. The shaft body 30 has the function of discharging the driving fluid introduced from the outside into the inside of the casing 20 into each closed space ER described later, and the function of moving axially in accordance with the operation of other components to move the push rod 60.

[0029] The shaft body 30 is integrally formed of an upper shaft body portion 32, a lower shaft body portion 34, and an intermediate shaft body portion 36 connecting the upper shaft body portion 32 and the lower shaft body portion 34.

[0030] The shaft upper portion 32 is a cylindrical body having a through hole in the axial direction and a male thread 32A formed on the outer circumferential surface. The through hole of the shaft upper portion 32 corresponds to a part of the elongated hole LH.

[0031] The lower shaft portion 34 is a cylindrical body having a hole opening at its upper axial end and a bottommost exhaust hole EH among the multiple exhaust holes EH. The hole opening at the upper axial end corresponds to the bottommost of the elongated holes LH, and the elongated holes LH communicate with the bottommost exhaust hole EH at their bottoms. The outer diameter of the upper end of the lower shaft portion 34 is designed to fit into the through holes 42d (an example of a first through hole) of each partition body 42. The outer diameter of the upper end of the lower shaft portion 34 is designed to be equal to the outer diameter of the rod-shaped cylindrical body 44b of each piston body 44. The lower shaft portion 34 forms a step at the boundary with the intermediate shaft portion 36, which will be described later. The boundary portion of the lower shaft portion 34 with the intermediate shaft portion 36 is designated as an annular flat surface 34A, and the outer peripheral surface is designated as an outer peripheral surface 34B. The lower end of the shaft lower portion 34 is a cylindrical body with a smaller outer diameter than the upper end, and is provided with a connecting portion 34C having a male thread for connecting the push rod 60 to the shaft 30.

[0032] The shaft intermediate section 36 is a cylinder having a through hole in the axial direction, and its upper axial end is connected to the shaft upper section 32 and its lower axial end is connected to the shaft lower section 34. All of the multiple exhaust holes EH (five exhaust holes EH in this embodiment) except for one exhaust hole EH formed in the shaft lower section 34 are formed in the shaft intermediate section 36. The shaft intermediate section 36 is designed to pass through the through holes 44d (an example of a second through hole) of each piston body 44, with a gap provided between it and each piston body 44.

[0033] [Multiple Assemblies] Each of the multiple assemblies 40 of this embodiment (assemblies 40A, 40B, 40C, 40D, 40E, and 40F, described below) is arranged inside the casing 20 so as to overlap one another along the axial direction, as shown in Figures 1 and 5.

[0034] 1 and 5, the multiple assemblies 40 (six in total) lined up from the upper end to the lower end in the axial direction are referred to as assemblies 40A, 40B, 40C, 40D, 40E, and 40F for convenience. Each of the assemblies 40B, 40C, 40D, 40E, and 40F has a partition body 42 and a piston body 44 of the same shape. In contrast, the assembly 40A has a partition body 42 of the same shape as the other assemblies 40 and a piston body 44H of a different shape. First, the assemblies 40B, 40C, 40D, 40E, and 40F, which have the same shape and configuration, will be described, and then the assembly 40A will be described.

[0035] <Assemblies 40B to 40F having the same shape and configuration> As shown in Figures 1 to 6, assemblies 40B, 40C, 40D, 40E, and 40F of this embodiment each have a partition body 42, a piston body 44, a small-diameter O-ring 46, and a large-diameter O-ring 48, which are fitted together to form the assembly.

[0036] (Partition body) As shown in FIGS. 3A and 3B, each partition 42 has a disk 42a, an outer cylindrical body 42b, and an inner cylindrical body 42c. A through hole 42d is formed in the center of the disk body 42a. The outer diameter of the disk body 42a is designed to be approximately the same as the inner diameter of the casing intermediate portion 26 of the casing 20. The outer cylinder 42b protrudes from the entire outer peripheral edge of the disk 42a to one side in the thickness direction of the disk 42a (the upper axial end side in this embodiment) and substantially abuts against the inner peripheral surface of the casing intermediate section 26 of the casing 20. The outer cylinder 42b also has a notch 42e formed therethrough. The notch 42e serves to exhaust air on the upper surface of the piston 44 when the piston 44 rises. The inner cylinder 42c is disposed between the through-hole 42d and the outer cylinder 42b, and protrudes from the disk 42a in the same direction as the outer cylinder 42b. The protruding height of the inner cylinder 42c is designed to be lower than the protruding height of the outer cylinder 42b.

[0037] As shown in Figure 1, the multiple partition bodies 42 are abutted against a flat surface 24A on the axial lower end side of the casing 20, and are biased from the axial upper end side by a coil spring 50 via a piston body 44H, and are arranged along the axial direction of the casing 20 with the tip end of the outer cylindrical body 42b of an adjacent partition body 42 abutting against the entire outer peripheral edge portion of the other side surface in the thickness direction of the disk body 42a of one partition body 42.

[0038] (Piston body) As shown in FIGS. 4A and 4B, each piston body 44 has an opposing body 44a, a rod-shaped cylindrical body 44b, and a fitting cylindrical body 44c. The opposing body 44a is disk-shaped with a through hole 44d formed in the center, and is designed to face the disk body 42a and the inner cylindrical body 42c in the axial direction of the casing 20 and to fit into the outer cylindrical body 42b (see Figures 1, 2, 5 and 6). The rod-shaped cylinder 44b protrudes from the through-hole 44d of the opposing body 44a toward the opposite side to the disk body 42a in the thickness direction of the opposing body 44a (toward the upper end of the casing 20 in the axial direction in this embodiment), and its inner diameter is designed so as not to abut against the outer circumferential surface of the shaft body 30. Furthermore, a through-hole 44f is formed in a part of the peripheral wall of the rod-shaped cylinder 44b, for sending the driving fluid exhausted from the corresponding exhaust hole EH of the shaft body 30 into the closed space ER. Although the through-holes 44f are shown in two directions in Figures 4A and 4B, they may be formed in three or four directions, etc. The fitting cylinder 44c is disposed between the through hole 44d and the entire outer periphery of the opposing body 44a, protrudes from the opposing body 44a toward the disk body 42a in the thickness direction of the opposing body 44a, and is designed to slidably fit into the inner cylindrical body 42c. The protruding height of the fitting cylinder 44c is designed to be equal to the protruding height of the inner cylindrical body 42c, for example. As shown in FIGS. 4A and 4B, the fitting cylinder 44c is formed with passage grooves 44e that allow the driving fluid exhausted from each exhaust hole EH of the shaft 30 to pass through.

[0039] As shown in Fig. 1, the piston bodies 44 are arranged along the axial direction of the casing 20, with the tip end of the rod-shaped cylindrical body 44b of one piston body 44 abutting against the entire inner peripheral edge of the surface on the other side in the thickness direction of the opposing body 44a of the adjacent piston body 44. Also, as shown in Figs. 1 and 2, each piston body 44 is fitted into each partition body 42 from the upper end side in the axial direction of the casing 20. The piston body 44 of one assembly 40 overlaps, in the radial direction of the casing 20, another assembly 40 (assembly 40B, for example) adjacent to the upper end side in the axial direction of the casing 20 of that one assembly 40 (assembly 40C, for example).

[0040] Furthermore, the piston body 42F of the assembly 40F, which is located at the lowest axial end of the casing 20 among the multiple assemblies 40B to F, is supported by the annular flat surface 34A of the shaft lower part 34 of the shaft body 30, as shown in Figures 1 and 5, and the assembly 40F forms a closed space ER together with the shaft lower part 34.

[0041] (Small and large diameter O-rings) As shown in Figures 1, 2, etc., the small diameter O-ring 46 is fitted between the inner cylindrical body 42c of the partition body 42 of one assembly 40 (assembly 40B as an example) and the rod-shaped cylindrical body 44b of the piston body 44 of another assembly 40 (assembly 40C as an example) adjacent to the lower axial end side of the casing 20 in the one assembly 40 (assembly 40B), sealing the inner cylindrical body 42c and the rod-shaped cylindrical body 44b. As shown in Figures 1, 2, etc., the large diameter O-ring 48 is fitted between the outer cylindrical body 42b of the partition body 42 of one assembly 40 (assembly 40B as an example) and the fitting cylindrical body 44c of the piston body 44 of that one assembly 40 (assembly 40B), sealing the outer cylindrical body 42b and the fitting cylindrical body 44c. The small diameter O-ring 46 and the large diameter O-ring 48 form a closed space ER together with the partition body 42 and piston body 44 of the assembly 40 (assembly 40B as an example) and the piston body 44 of another assembly 40 (assembly 40C as an example) adjacent to the assembly 40 (assembly 40B).

[0042] <Assembly 40A> Next, assembly 40A of this embodiment will be described mainly with reference to Figure 1. Assembly 40A includes a partition body 42, a piston body 44H (an example of an uppermost piston body), a small-diameter O-ring 46, and a large-diameter O-ring 48, which are fitted together to form the assembly. Here, partition body 42, small-diameter O-ring 46, and large-diameter O-ring 48 have the same shapes as those of assemblies 40B, 40C, 40D, 40E, and 40F, respectively.

[0043] (irregularly shaped piston body) 1 and 5, piston body 44H of this embodiment has a different shape from piston body 44 of assemblies 40B, 40C, 40D, 40E, and 40F. More specifically, piston body 44H has an opposing body 44a, a rod-shaped cylindrical body 44L, and a fitting cylindrical body 44c. Piston body 44H differs from piston body 44 in that rod-shaped cylindrical body 44b of piston body 44 is replaced with rod-shaped cylindrical body 44L.

[0044] The rod-shaped cylindrical body 44L is longer than the rod-shaped cylindrical body 44b, and has a thicker peripheral wall and a larger outer diameter than the rod-shaped cylindrical body 44b. The rod-shaped cylinder 44L has a through hole HX formed along its axis from the upper end to the lower end, which is connected to the introduction hole 22A at the upper end and the long hole LH of the shaft body 30 at the lower end, and is connected to the shaft body 30 at the lower end.

[0045] An internal thread HY is formed on the inner peripheral surface of the lower end side (shaft body 30 side) of the through hole HX of the rod-shaped cylindrical body 44L. The piston body 44 is connected to the shaft body 30 by screwing the internal thread HY into an external thread 32A formed on the outer peripheral surface of the shaft body upper part 32 of the shaft body 30.

[0046] In this way, the uppermost piston body 44H is connected to the shaft body 30 by threaded engagement, the lowermost piston body 44 is supported by the annular flat surface 34A of the lower shaft body 34 of the shaft body 30, and the tip end of the rod-shaped cylindrical body 44b of an adjacent piston body 44 abuts against the entire inner peripheral edge portion of the other side surface in the thickness direction of the opposing body 44a of one piston body 44.By adopting this configuration, when the driving fluid is introduced from the shaft body 30 into the pressure chamber and moves in the valve opening direction, the multiple piston bodies 44 move integrally with the shaft body 30 without separating.

[0047] [Coil spring] 1 and 5, the coil spring 50 of this embodiment is disposed between a recess formed in the casing upper portion 22 of the casing 20 and the opposing body 44a of the piston body 44H in a state compressed from its natural length, and has the function of biasing the piston body 44H from the upper end side to the lower end side. Specifically, the coil spring 50 abuts against the opposing body 44a of the piston body 44H to bias the piston body 44H.

[0048] [Push rod] The push rod 60 of this embodiment is disposed at the lower axial end of the casing 20 of the shaft body 30, and is configured to be movable in accordance with axial movement of the shaft body 30. In this embodiment, the push rod 60 is connected to the connecting portion 34C of the shaft lower portion 34 of the shaft body 30 by screwing, for example.

[0049] <Function and configuration of the opening / closing valve mechanism including the actuator of this embodiment> 7 is a vertical cross-sectional view of an on-off valve mechanism 110 including the actuator of this embodiment. The on-off valve mechanism 110 including the actuator of this embodiment (hereinafter referred to as on-off valve mechanism 110) has the above-mentioned actuator 10, a valve element 70, and a body 80.

[0050] [Valve Body 70] The valve body 70 has a bellows structure as shown in FIG.

[0051] The welded bellows 71 is formed by welding a stem 71A, a bellows flange 71B, and a bellows 71C as shown in FIG. 7. The upper end of the stem 71A is formed with a male thread that is screwed together with the lower end of the push rod 60, and the lower end of the stem 71A is formed with a recess for accommodating the upper end of the disc packing 72.

[0052] The upper end of the disc packing 72 is fixed to the recess at the lower end of the stem 71A by means of crimping or the like, and the lower end abuts or is separated from the opening of the flow path formed in the body 80 (described later) all around its circumference, thereby allowing or blocking the flow of fluid passing through the flow path.

[0053] [Body 80] As shown in Figure 7, the body 80 is a block-shaped member in which a plurality of flow paths are formed, defining inflow paths for the inflow of fluid and outflow paths for the outflow of fluid. One side of each flow path opens at the lower end of the body 80, and the other side opens at a housing recess (described later), and the flow paths are connected to each other. An internal thread is formed on the inner circumferential surface of the housing recess to be mated with an external thread of the casing lower part 24, and the actuator 10 is fixed to the body 80 by tightening it via the bellows flange 71B. In addition, through holes are formed at both longitudinal ends of the body 80 for inserting fastening bolts.

[0054] In other words, the opening / closing valve mechanism 110 is formed by threading the lower end of the push rod 60 in the actuator 10 to the upper end of the valve body 70, and by threading the actuator 10 to a recess formed in the body 80, the valve body 70 rises and falls in accordance with the operation of the actuator 10 described below, thereby opening and closing the fluid flow path formed in the body 80 and controlling the supply and cut-off of fluid.

[0055] In this embodiment, the valve element has a bellows structure, but is not limited to this and may be a diaphragm, etc. Also, although the valve element 70 is configured to be connected to the push rod 60 by screwing, it may be configured such that the push rod 60 is not provided and an internal thread is formed in the connecting portion 34C of the shaft lower portion 34, to which the external thread at the upper end of the stem 71A is connected.

[0056] <Operation of the actuator and on-off valve mechanism of this embodiment> Next, the operation of the actuator 10 and on-off valve mechanism 110 of this embodiment will be described with reference to Figures 1, 5, and 7. Here, an external device that supplies a driving fluid under the control of a control device (not shown) is attached to the introduction hole 22A formed in the casing 20 of the actuator 10. The control device also outputs rectangular pulse signals of an on signal and an off signal at a predetermined cycle, causing the external device to supply the driving fluid while the on signal is being output, and preventing the external device from supplying the driving fluid while the off signal is being output.

[0057] Actuator 10 in its initial state (zero stroke state) is as shown in Figure 1. In this state, piston body 44H of assembly 40A and each of piston bodies 44 of assemblies 40B to 40F are positioned at the lowest axial position among their respective movable positions.

[0058] First, the control device outputs a pulse signal to an external device, and when an ON signal is input to the external device, driving fluid is introduced from the external device into the inlet hole 22A of the casing 20. The driving fluid introduced into the inlet hole 22A flows through the through hole HX of the piston body 44H and is further introduced into the elongated hole LH of the shaft body 30. The driving fluid supplied to the elongated hole LH is exhausted from the multiple exhaust holes EH connected to the elongated hole LH into each of the closed spaces ER formed in the multiple assemblies 40. The driving fluid exhausted to each of the closed spaces ER passes through the passing groove 44e and is supplied to the entirety of each of the closed spaces ER.

[0059] As the time it takes for the driving fluid to be exhausted from each exhaust hole EH increases, the pressure in each closed space ER increases. As a result, the piston body 44H of the assembly 40A and each of the piston bodies 44 of the assemblies 40B-F are subjected to a force from their respective closed spaces ER, directed from the lower end to the upper end in the axial direction of the casing 20. When this force exceeds the biasing force of the coil spring 50, which biases the piston body 44H from the upper end in the axial direction, and the frictional forces of all the small-diameter O-rings 46 and large-diameter O-rings 48, the piston body 44H and each of the piston bodies 44 of the assemblies 40B-F move from the lower end to the upper end in the axial direction. Accordingly, the shaft body 30 connected to the piston body 44H also moves together with the piston body 44H. As a result, the push rod 60 connected to the shaft body 30 also moves together with the piston body 44H. Figure 5 shows the actuator 10 in a state where a predetermined amount of driving fluid has been introduced into each closed space ER, resulting in the piston body 44H and each piston body 44 of assemblies 40B to 40F, the shaft body 30, and the push rod 60 being positioned at the uppermost axial position among their movable positions (full stroke state).

[0060] As push rod 60 moves, welded bellows 71 and disc packing 72 move from the lower end to the upper end in the axial direction. This movement opens the fluid flow paths formed in the housing recess of body 80, allowing fluid to flow.

[0061] Next, when the control device switches the pulse signal output to the external device to an OFF signal, the supply of driving fluid from the external device to the inlet hole 22A of the casing 20 is stopped. Accordingly, the driving fluid is no longer supplied to each closed space ER from each exhaust hole EH. The driving fluid inside each closed space ER is discharged to the outside via the same flow path as when the driving fluid was introduced from the external device. Then, due to the decrease in pressure in each closed space ER and the biasing force of the coil spring 50, the actuator 10 changes from the full stroke state shown in FIG. 5 to the zero stroke state.

[0062] In accordance with this movement, welded bellows 71 and disc packing 72 move from the upper end side to the lower end side in the axial direction, closing the fluid flow path formed in the receiving recess of body 80. Thus, the fluid is shut off.

[0063] <Fluid control device including an on-off valve mechanism> Fig. 8 is an external perspective view of a fluid control device 200 including an on-off valve mechanism 110. As shown in Fig. 8, the fluid control device 200 is provided with a metal base plate and rail members arranged in the width direction and extending in the longitudinal direction. Fluid control devices including the on-off valve mechanism 110 of the present invention are installed on this rail member via a plurality of joint blocks, and the plurality of joint blocks form flow paths through which the fluid flows from the upstream side to the downstream side. Here, fluid control equipment refers to equipment used in a fluid control device that controls the flow of a fluid, and has a body 80 that defines a fluid flow path.Specific examples include, but are not limited to, an on-off valve mechanism 110, a regulator 110B, a pressure gauge 110C, an on-off valve (three-way valve) 110D, a mass flow controller 110E, etc.

[0064] <Effects of the Actuator and Opening / Closing Valve Mechanism of the Present Embodiment> Next, the effects of the actuator 10 and the on-off valve mechanism 110 of this embodiment will be described with reference to the drawings.

[0065] [First effect] This effect is achieved by the configuration in which the multiple piston bodies 44 are arranged integrally with the shaft body 30 without contacting the shaft body 30 and are aligned in the axial direction of the casing 20.

[0066] For example, in the case of the configuration of the prior art document mentioned above, a configuration (hereinafter referred to as a comparative configuration) is adopted in which a pressure chamber (corresponding to a closed space in this embodiment) into which a driving fluid is introduced is formed in each assembly by arranging the cylindrical shaft rods constituting each piston body side by side in the axial direction of multiple assemblies (combinations including partitions and piston bodies) (see FIG. 9). That is, in the actuator of this comparative configuration, a plurality of assemblies each composed of a piston body and a partition are stacked in the axial direction by themselves, and are arranged inside a casing body with their upper ends biased by a coil spring.

[0067] As described above, in the case of the comparative actuator, immediately after the driving fluid introduced into the casing body from the outside is sent into the pressure chamber of one assembly, the piston body of that assembly separates from the piston bodies of the other assemblies, and the piston bodies rise in the order in which they are arranged, that is, there is a risk that the multiple piston bodies will not rise as a unit (see FIG. 9). As a result, there is a time lag between when the driving fluid is introduced into the casing and when the push rod reaches its full stroke state.

[0068] In contrast to this, in the present embodiment, the uppermost piston body 44H of the multiple piston bodies 44 is fixed to the shaft body 30 by screwing, the lowermost piston body 44 abuts against the upper end surface of the shaft body lower part 34, and the piston bodies also abut in the axial direction, so that the shaft body 30 and the multiple piston bodies are integrally arranged in the axial direction of the casing 20 (see FIGS. 1, 2, 5, and 6). Therefore, in the present embodiment, one piston body 44 will not separate and move. Therefore, the actuator 10 of this embodiment has superior responsiveness compared to the comparative embodiment (the time from when the driving fluid is introduced into the casing 20 until the push rod 60 reaches the full stroke state is short).

[0069] As mentioned above, the comparative actuator employs a configuration in which the cylindrical shafts of the piston bodies are aligned in the axial direction to form air passages for the driving fluid, thereby forming pressure chambers into which the driving fluid is introduced in each assembly (see Figure 9). Due to mechanical tolerances, such as the machining accuracy and dimensional variations of the shafts, there is a risk that the axes of the axial air passages of the piston bodies may be misaligned due to the mechanical tolerances. If this misalignment results in flow resistance for the driving fluid, it will correspondingly slow down the time it takes for the driving fluid to reach each pressure chamber. In contrast to this, in the case of this embodiment, in the first place, there is no increase in flow path resistance, as in the comparative example, in the flow paths for passing the driving fluid through each closed space ER. Therefore, according to the actuator 10 of this embodiment, there is less individual variation in response compared to the comparative embodiment.

[0070] As mentioned above, the actuator of the comparative example employs a configuration in which the cylindrical shafts constituting each piston body are aligned in the axial direction to form pressure chambers into which the drive fluid is introduced in each assembly. That is, each shaft in the comparative example functions as both an axial flow passage and a shaft that moves in the axial direction. To improve the responsiveness required of the actuator, it is preferable to increase the cross-section (flow passage area) of the air passage of each shaft. However, the larger the cross-section of the air passage of each shaft—in other words, the thinner the peripheral wall of each shaft—the more difficult it becomes to maintain the shape of the shaft while exerting a reaction force on the small-diameter O-ring 46. As a result, it becomes more difficult for each shaft to move stably along the axial direction. In contrast, in the actuator 10 of this embodiment, the function of the flow path in the axial direction is provided to the shaft 30, not to each piston 44 (see Figures 2, 6, etc.). In other words, in the case of this embodiment, the function of the air passage for the driving fluid introduced into each pressure chamber is provided to the shaft 30, which is a separate member, not to each piston 44, so the above-mentioned problem that can arise in the comparative embodiment does not occur. Therefore, in the actuator 10 of this embodiment, the axial movement of each piston body 44, 44H is more likely to be stable than in the comparative embodiment. Accordingly, in the actuator 10 of this embodiment, the durability of each assembly 40 is higher than in the comparative embodiment.

[0071] [Second effect] This effect is achieved by connecting the piston body 44H to the shaft body 30. 1 and 5, an internal thread HY is formed on the inner peripheral surface of the lower end side (shaft body 30 side) of the through hole HX of the rod-shaped cylinder 44L. The rod-shaped cylinder 44L is connected to the shaft body 30 by screwing the internal thread HY into an external thread 32A formed on the outer peripheral surface of the shaft body upper part 32 of the shaft body 30. Therefore, according to the actuator 10 of this embodiment, the piston body 44H can be connected to the shaft body 30 without using parts (e.g., screws, screw holes, etc.) for connecting the piston body 44H to the shaft body 30 and without increasing the flow path resistance.

[0072] [Third effect] This effect is achieved by connecting the push rod 60 to the shaft body 30 . In the configuration of the aforementioned prior art document, the push rod is not fixed to any part of the assembly, so the push rod can move axially from one defined position to another defined position due to the operation of the actuator in this configuration, but not vice versa. In contrast to this, in the actuator 10 of this embodiment, as shown in FIGS. 1 and 5, the push rod 60 is connected to the connecting portion 34C of the shaft body 30. Therefore, according to the actuator 10 of this embodiment, the push rod 60 can be moved in conjunction with the movement of the shaft body 30 in both axial directions.

[0073] [Fourth Effect] This effect is achieved by arranging a plurality of assemblies 40 integrally, each penetrating the shaft body 30 . As mentioned above, the comparative actuator employs a configuration in which the shaft rods that make up each piston body are connected in the axial direction (see Figure 9). Therefore, due to mechanical tolerances such as the machining accuracy and dimensional variations of each shaft rod, there is a risk that one piston body will move axially while misaligning with the axis of the partition into which its tip is fitted. As a result, the small-diameter O-ring sandwiched between one piston body and the partition will deform only in a biased portion in the circumferential direction due to this misalignment, and will become distorted in shape. In contrast, in the present embodiment, a configuration is adopted in which multiple assemblies 40 each penetrate the shaft body 30 and are arranged integrally (see Figures 1 and 5), so the above-mentioned misalignment problem that can occur in the comparative embodiment does not occur or is unlikely to occur in the first place. Therefore, in the actuator 10 of this embodiment, the small-diameter O-ring 46 and the large-diameter O-ring 48 are less likely to deform unevenly than in the comparative embodiment. Accordingly, in the actuator 10 of this embodiment, each assembly 40 is less likely to break (has high durability) than in the comparative embodiment.

[0074] [Other effects] Furthermore, in the opening / closing valve mechanism 110 using the actuator 10 of this embodiment, the valve element 70 is connected to the push rod 60, which has the effect of allowing the valve element 70 to move in conjunction with the movement of the shaft body 30 in both axial directions, just like the push rod 60. Furthermore, it is also possible to implement a configuration in which the push rod 60 is not provided as an opening / closing valve mechanism 110 using the actuator 10. In this case, by designing a connecting portion 34C to which the valve body 70 can be connected to the lower part of the shaft body 34 and configuring the valve body to move in conjunction with the operation of the actuator 10, an effect similar to the third effect can be obtained.

[0075] <<Multiple Modifications>> As described above, the present invention has been described using the above-mentioned embodiment as an example, but the present invention is not limited to this embodiment. The technical scope of the present invention also includes, for example, several modified examples described below.

[0076] For example, in the present embodiment, the number of the plurality of assemblies 40 is described as six, for example. However, the number of the plurality of assemblies 40 does not have to be six. For example, it may be two to five, or seven or more.

[0077] Furthermore, for example, in the present embodiment, the push rod 60 has been described as being housed inside the casing 20. However, the push rod 60 may be disposed outside the casing 20. Furthermore, the push rod 60 does not necessarily have to be a component of the actuator 10, as long as the valve element 70 can open or close the flow path in accordance with the operation of the actuator 10.

[0078] Furthermore, for example, in this embodiment, the coil spring 50 is disposed on the upper end side in the axial direction of the casing 20. However, it is also possible to modify the actuator by disposing the coil spring 50 on the lower end side in the axial direction of the casing 20 and arranging the multiple assemblies 40 in an orientation facing in the opposite axial direction. In this way, the actuator 10 of this embodiment can be modified into an actuator (not shown) in which the zero stroke position and full stroke position are reversed.

[0079] Also, for example, in this embodiment, each assembly 40 has been described as including a small-diameter O-ring 46 and a large-diameter O-ring 48. However, if multiple closed spaces ER can be formed inside the casing 20 using the partition body 42F and the piston body 44, one or both of the small-diameter O-ring 46 and the large-diameter O-ring 48 may be omitted. For example, one or both of the small-diameter O-ring 46 and the large-diameter O-ring 48 may be rubber rings having a rectangular cross section.

[0080] Also, for example, in this embodiment, the outer diameter of the shaft body 30 and the inner diameter of the rod-shaped cylinder 44b of the piston body 44 are designed not to come into contact with each other, and the multiple assemblies 40 are arranged integrally with the shaft body 30 without coming into contact with the shaft body 30. However, as long as the exhaust hole EH of the corresponding shaft body 30 and the through-hole 44f formed in the rod-shaped cylinder 44b overlap in the radial direction and the driving fluid is introduced into each closed space ER, the shaft body 30 and the piston body 44 may be fitted together, and this fitting makes it easier for the shaft body 30 and the piston body 44 to move integrally, resulting in an actuator with better responsiveness. [Explanation of symbols]

[0081] 10 Actuator 20 Casing 22 Upper part of casing 22A introduction hole 24 Lower casing 24A Flat surface (example of contact surface) 24B through hole 26 Casing middle section 30 shaft body 32 Upper part of shaft 32A male thread 34 Lower part of shaft (example of cylindrical body) 34A Circular Plane 34B Outer surface 36 Middle part of shaft 40 assembly 40A assembly 40B assembly 40C assembly 40F assembly 42 Partition Body 42F Partition body (Example of the bottom partition body) 42a Disk 42b outer cylinder 42c Inner cylinder 42d through hole (an example of a first through hole) 42e Notch 44 Piston body 44H Piston body (Example of the top end piston body) 44L rod-shaped cylinder 44a Opposite body 44b Rod-shaped cylinder 44c Fitting cylinder 44d Through hole (an example of a second through hole) 44e Passage groove 44f through hole 46 Small diameter O-ring 48 Large diameter O-ring 50 Coil spring (an example of a biasing body) 60 push rod 110 Opening and closing valve mechanism 70 Valve body 71 Welded bellows 71A stem 71B Bellows flange 71C Bellows 72 Disc packing 80 Body 200 Fluid control device 210 Gas Line 220 Block joint 110B Regulator 110C Pressure Gauge 110D On-off valve (3-way valve) 110E Mass Flow Controller EH exhaust hole ER closed space HX through hole (an example of a third through hole) HY female thread LH long hole

Claims

1. a casing having an introduction hole formed at one end thereof for introducing a driving fluid from the outside; a shaft disposed within the casing along the axial direction of the casing, the shaft having an elongated hole that opens in the same direction as the inlet hole and extends along the axial direction, and a plurality of exhaust holes that communicate with the elongated hole and are arranged at predetermined intervals along the axial direction, the shaft introducing the driving fluid from the inlet hole through the opening of the elongated hole and discharging it from the plurality of exhaust holes; a partition body including a disk body having a first through hole formed in the center and an outer cylindrical body extending from the periphery of the disk body and abutting against the inner peripheral surface of the casing; a piston body having a rod-shaped cylindrical body with a second through hole formed at a center thereof and inserted into the first through hole, the piston body being arranged at a plurality of positions inside the casing corresponding to the plurality of exhaust holes; a biasing body disposed inside the casing; Equipped with Each partition body in the plurality of assemblies abuts against an adjacent partition body in the axial direction at the end surface of the outer cylindrical body and the disk body, and each piston body abuts against an adjacent piston body in the axial direction at the rod-shaped cylindrical bodies, Each piston body passes through the second through-hole so as to be able to abut against the shaft body, and together with each partition body, forms a closed space communicating with each exhaust hole at each position of the plurality of exhaust holes; Either the piston body arranged on the most one end side or the most other end side is connected to the shaft body, The biasing member biases the piston member connected to the shaft member in a direction against the pressure of the driving fluid. Actuator.

2. an internal thread is formed on an inner peripheral surface of the other end of the second through hole in the piston body on the one end side, A male thread is formed on the outer peripheral surface of one end of the shaft body, The first end side piston body is connected to the shaft body by fastening the female screw and the male screw together. The actuator of claim 1 .

3. a portion of the shaft body on the other end side in the axial direction includes a cylindrical body having an annular flat surface facing the one end side in the axial direction and an outer peripheral surface having the same outer diameter as the rod-shaped cylindrical body, the cylindrical body supports, on the annular flat surface, the piston body that is located at the other end in the axial direction among all the piston bodies that constitute the plurality of assemblies, and forms the closed space together with the assembly that is located at the other end in the axial direction among the plurality of assemblies. The actuator of claim 1 .

4. The actuator according to claim 3 , wherein the portion on the other axial end side has a connecting portion.

5. An opening / closing valve mechanism having the actuator according to any one of claims 1 to 4.

6. The on-off valve mechanism according to claim 5 , further comprising a bellows structure connected to the connecting portion.

7. A fluid control device comprising the on-off valve mechanism according to claim 6.

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