Vortex-type flow regulation valve

Abstract

A vortex-type flow regulation valve (11) comprises: a vortex chamber (27) that is defined by a cylinder-shaped circumferential side wall (13), and a first end wall (15) and a second end wall (17) that are provided at either end of the same; an inlet flow passage (19) that extends along an inlet flow passage center axis (P1) and opens in the circumferential side wall (13); an outlet flow passage (21) that extends along an outlet flow passage center axis (P2) and opens in the first end wall (15); a protrusion (23) that protrudes into the vortex chamber (27) from one of the first end wall (15) and the second end wall (17); and a driving unit (25) that causes the protrusion (23) to move toward and away from the other of the first end wall (15) and the second end wall (17), within the vortex chamber (27). The inlet flow passage (19) is provided such that the inlet flow passage center axis (P1) passes through a location that is distanced from a vortex chamber center axis (O), and the movement of the protrusion (23) regulates the flow rate of a fluid flowing out from the outlet flow passage (21).

Description

Vortex flow control valve

[0001] The present invention relates to a flow control valve used in fluid transport piping in various industrial fields such as chemical plants, semiconductor manufacturing fields, liquid crystal manufacturing fields, and food manufacturing fields.

[0002] Needle valves are commonly used for flow rate adjustment in various industrial fields. As described in Patent Document 1, for example, a needle valve adjusts the flow rate of a fluid flowing through the gap between the needle and the valve seat by inserting the tapered tip of a valve element called a needle into a valve seat having a through-hole and moving the peripheral surface of the tip of the needle toward and away from the valve seat to change the gap between the needle and the valve seat. To enable fine adjustment of the flow rate, the gap between the needle and the valve seat in a needle valve is narrower than in other flow paths. In particular, the gap between the needle and the valve seat becomes very narrow near the lower limit of the needle valve's operating flow rate range.

[0003] Patent No. 5144880 Publication No. 59-5209

[0004] As described above, needle valves have a narrow gap between the needle and the valve seat, particularly near the lower limit of the needle valve's operating flow range. Therefore, if the needle and the valve seat are not coaxial, they may come into contact and slide when adjusting to a low flow rate, even though they should not. This can result in wear on the needle and the valve seat. Such wear changes the relationship between the needle and the valve seat, i.e., the needle valve's opening and flow rate, making it difficult to accurately adjust the flow rate. Furthermore, particles generated by wear can be mixed into the fluid. Such particle mixing into the fluid is a major problem, particularly in the semiconductor manufacturing industry. When an electric actuator is used to drive the needle and frequently adjust the flow rate using feedback control, the needle is constantly reciprocating, making the above-mentioned problem particularly pronounced. Furthermore, changes in the relationship between the needle valve's opening and flow rate require readjustment of control parameters, such as feedback control. In such cases, the needle valve is often replaced at the end of its useful life, resulting in increased maintenance costs.

[0005] One method for preventing sliding between the valve disc and the valve seat is to use a vortex-type fluid element utilizing a swirling flow, as disclosed in Patent Document 2, for example. The vortex-type fluid element disclosed in Patent Document 2 includes a vortex chamber having an outlet port at its center, an input nozzle connected to the outer periphery of the vortex chamber and directing the fluid from the input port toward the output port, and a control nozzle that ejects a control flow that swirls the fluid ejected from the input nozzle near the outlet of the vortex chamber. In the interference region, the control flow ejected from the control nozzle collides with the jet ejected from the input nozzle and deflects it, generating a vortex within the vortex chamber. Generating a vortex creates a pressure difference between the interference region and the output port, increasing flow resistance and thereby controlling the output flow rate. However, while this type of vortex-type fluid element does not cause contact between the valve disc and the valve seat, it is necessary to adjust the flow rate of the control flow ejected from the control nozzle in order to control the flow rate. Therefore, a flow rate control valve is required to adjust the flow rate of the control flow, and ultimately, there remains a risk of particles being mixed into the control flow.

[0006] Therefore, an object of the present invention is to solve the problems present in the prior art and to provide a flow control valve in which contact between the valve body and the valve seat does not occur within the area in contact with the fluid to be controlled.

[0007] In view of the above object, the present invention provides a vortex type flow control valve comprising: a vortex chamber defined by a cylindrical peripheral side wall and first and second end walls provided at both ends of the peripheral side wall and facing each other; an inlet flow path extending along a central axis of an inlet flow path and opening onto the peripheral side wall; and an outlet flow path extending along a central axis of an outlet flow path and opening onto the first end wall, wherein a fluid flowing in from the inlet flow path forms a vortex within the vortex chamber and flows out of the outlet flow path, and the inlet flow path is arranged such that the central axis of the inlet flow path passes through a position away from a central axis of the vortex chamber connecting the center of the first end wall and the center of the second end wall, and the vortex type flow control valve further comprises: a protrusion protruding into the vortex chamber from one of the first end wall and the second end wall; and a drive unit for moving the protrusion toward and away from the other of the first end wall and the second end wall within the vortex chamber, wherein the flow rate of the fluid flowing out of the outlet flow path is adjusted by movement of the protrusion.

[0008] In the above-described vortex flow control valve, a vortex chamber is defined by a cylindrical peripheral wall and opposing first and second end walls provided at both ends thereof. The inlet flow passage is provided so that the central axis of the inlet flow passage, which opens into the peripheral wall, passes through a position away from the vortex chamber central axis connecting the centers of the first and second end walls of the vortex chamber. The outlet flow passage opens into the first end wall. Thus, fluid flowing through the inlet flow passage becomes a swirling flow within the vortex chamber, swirling, and then flows out of the outlet flow passage. As a result, pressure loss occurs depending on the length of the swirling flow (i.e., the length of the vortex flow streamline) from when it enters the inlet flow passage to when it exits the outlet flow passage. Furthermore, the swirling flow (vortex flow) collides with a protrusion provided on one of the first and second end walls so as to protrude into the vortex chamber, and a portion of the swirling flow that collides with the protrusion takes a shortcut toward the outlet flow passage. As the protrusion approaches the other of the first end wall and the second end wall, the gap between the top of the protrusion and the other of the first end wall and the second end wall decreases, increasing the proportion of swirling flows that collide with the protrusion, thereby increasing the proportion of swirling flows that take a shortcut toward the outlet flow path. Conversely, as the protrusion moves away from the other of the first end wall and the second end wall, the gap between the top of the protrusion and the other of the first end wall and the second end wall increases, increasing the proportion of swirling flows that pass through the gap without colliding with the protrusion, thereby decreasing the proportion of swirling flows that take a shortcut toward the outlet flow path. As described above, the pressure loss of fluid flowing from the inlet flow path to the outlet flow path in the vortex chamber is proportional to the length of the swirling flow (vortex flow) streamline from the inlet flow path to the outlet flow path. Therefore, as the proportion of swirling flows that collide with the protrusion and take a shortcut toward the outlet flow path increases, the overall length of the swirling flow streamline from the inlet flow path to the outlet flow path decreases, reducing the pressure loss and increasing the flow rate out of the outlet flow path. On the other hand, if the proportion of the swirling flow that collides with the protrusion and takes a shortcut toward the outlet flow passage decreases, the overall length of the swirling flow streamline from the inlet flow passage to the outlet flow passage increases, increasing pressure loss and reducing the flow rate out of the outlet flow passage. Utilizing this characteristic, it is possible to adjust the flow rate of the fluid out of the outlet flow passage by using the drive unit to move the protrusion provided on one of the first end wall and the second end wall toward or away from the other of the first end wall and the second end wall.

[0009] In the above-described vortex flow control valve, it is preferable that the protrusion is provided at a position eccentric to the central axis of the vortex chamber. In the vortex chamber, the center of the vortex chamber becomes the center of the vortex flow. Therefore, by arranging the protrusion in this manner, the swirling flow (vortex flow) in the vortex chamber is more likely to collide with the protrusion.

[0010] It is more preferable that the protrusion is provided so that at least a portion thereof overlaps an extension of the inlet flow path leading to the vortex chamber. If the protrusion is arranged so as to overlap an extension of the inlet flow path, the fluid flowing from the inlet flow path into the vortex chamber will reliably collide with the protrusion, making it easier to achieve the above-mentioned effects.

[0011] It is also preferable that the first end wall and the second end wall have a circular or elliptical shape, in which case the cross section of the vortex chamber perpendicular to the central axis of the vortex chamber, i.e., the peripheral wall of the vortex chamber, also has a circular or elliptical shape, so that the fluid flows along the peripheral wall, making it easier to generate a smooth vortex flow.

[0012] In one embodiment, the outlet flow passage may be provided such that a central axis of the outlet flow passage extends through a position spaced apart from a central axis of the inlet flow passage.

[0013] In another embodiment, the outlet flow passage may be provided such that the axis of the outlet flow passage extends on the central axis of the vortex chamber.

[0014] The outlet flow passage may be provided such that the outlet flow passage axis extends through a position displaced from the vortex chamber central axis toward the inlet flow passage central axis.

[0015] The protrusion may be provided at a position offset from the central axis of the outlet flow path.

[0016] The protrusion may have a circular or elliptical cross section.

[0017] The drive unit may drive the protrusion to change the protrusion length into the vortex chamber.

[0018] The protrusion may be provided on the second end wall. In this case, the first end wall may be made of a diaphragm, the protrusion may be attached to the diaphragm, and the driving unit may drive the protrusion via the diaphragm.

[0019] According to the present invention, a vortex flow is generated in a vortex chamber, and the protrusion is moved relative to the opposing end wall to change the proportion of swirling flow that collides with the protrusion. This changes the proportion of swirling flow that collides with the protrusion and takes a shortcut toward the outlet flow path, thereby increasing or decreasing the overall length of the swirling flow streamline from the inlet flow path to the outlet flow path. By utilizing this characteristic, the protrusion on one of the first end wall and the second end wall is moved toward or away from the other of the first end wall and the second end wall using a drive unit, thereby adjusting the flow rate of the fluid flowing out of the outlet flow path. This eliminates the need to provide a valve disc and a valve seat in an area that contacts the fluid to be controlled, thereby eliminating the contact area between the valve disc and the valve seat. This eliminates the need to reset flow rate control parameters due to wear on the valve disc and the valve seat, and also reduces particle contamination of the fluid.

[0020] 7 is a partially cutaway perspective view showing the overall configuration of a vortex-type flow control valve according to a first embodiment of the present invention, with a portion cut away so that the interior can be seen. FIG. 1 is a plan view of the vortex-type flow control valve shown in FIG. 1 as seen from above. FIG. 2 is a side view of the vortex-type flow control valve shown in FIG. 1 as seen from the side of FIG. 1. FIG. 3 is an explanatory diagram schematically showing the flow in a vortex chamber of the vortex-type flow control valve shown in FIG. 1 as seen from above. FIG. 4 is an explanatory diagram schematically showing the flow in a vortex chamber of the vortex-type flow control valve shown in FIG. 1 as seen from the side of FIG. 1. FIG. 5 is an explanatory diagram schematically showing the flow in a state in which a protrusion does not protrude into the vortex chamber of the vortex-type flow control valve shown in FIG. 1. FIG. 6 is an explanatory diagram schematically showing the flow in a state in which a protrusion slightly protrudes into the vortex chamber of the vortex-type flow control valve shown in FIG. 1. FIG. 7 is an explanatory diagram schematically showing the flow in a state in which the protrusion protrudes further into the vortex chamber of the vortex-type flow control valve shown in FIG. 10A and 10B .

[0033] FIG. 10B is an explanatory diagram illustrating the configuration and dimensions of a vortex-type flow control valve used in an experiment, showing the vortex-type flow control valve with the upper end wall (second end wall) removed as viewed from above.

[0034] FIG. 10C is an explanatory diagram illustrating the configuration and dimensions of a vortex-type flow control valve used in an experiment, showing the vortex-type flow control valve with the upper end wall (second end wall) removed as viewed from the side.

[0035] FIG. 10D is a piping diagram showing the arrangement of the vortex-type flow control valve, measuring instruments, and control instruments used in the experiment.

[0036] FIG. 10E is a graph plotting measurement results of the relationship between the protrusion length and the flow rate when the differential pressure between the upstream pressure and the downstream pressure is changed, obtained by an experiment using the vortex-type flow control valve shown in FIGS. 10A and 10B .

[0037] FIG. 10F is an explanatory diagram illustrating the definition of the protrusion and the position of the outlet flow path of a vortex-type flow control valve in a numerical simulation, showing the vortex-type flow control valve with the upper end wall (second end wall) removed as viewed from above. 14 is a graph plotting the relationship between the position of the protrusion and the flow rate difference ΔQ (amount of change in flow rate from the outlet flow path) when the length of the protrusion is changed from 0.5 mm to 3.5 mm, obtained by a numerical simulation using the vortex flow control valve shown in FIG. 13.14 is a line graph plotting the relationship between the protrusion length and the flow rate Q (flow rate from the outlet flow path) when the protrusion is disposed at an angular position of 90° and at positions displaced by distances of 3.5 mm, 5.5 mm, and 7.5 mm from the center of the vortex chamber in a numerical simulation using the vortex-type flow control valve shown in FIG. 13. FIG. 14 is a line graph plotting the relationship between the protrusion length and the flow rate Q when the protrusion is disposed at an angular position of 180° and at positions displaced by distances of 3.5 mm, 5.5 mm, and 7.5 mm from the center of the vortex chamber in a numerical simulation using the vortex-type flow control valve shown in FIG. 13. FIG. 14 is an explanatory diagram for explaining the protrusion of the vortex-type flow control valve used in the numerical simulation using the vortex-type flow control valve shown in FIG. 13, showing a protrusion having a circular cross-sectional shape (shape 1). FIG. 14 is an explanatory diagram for explaining the protrusion of the vortex-type flow control valve used in the numerical simulation using the vortex-type flow control valve shown in FIG. 13, showing a protrusion having a diamond cross-sectional shape (shape 2). 14 is an explanatory diagram for explaining a protrusion of the vortex-type flow control valve used in a numerical simulation using the vortex-type flow control valve shown in Fig. 13, showing a protrusion having a square cross-sectional shape (shape 3). In the numerical simulation using the vortex-type flow control valve shown in Fig. 13, a protrusion having a cross-section of shape 1 is disposed at an angular position of 90° and a distance of 3.5 mm from the center of the vortex chamber. In the numerical simulation using the vortex-type flow control valve shown in Fig. 13, a bar graph comparing the flow rate difference ΔQ when the protrusion length is changed from 0.5 mm to 3.5 mm for each shape of the protrusion, under the condition that the protrusion is disposed at an angular position of 90° and a distance of 7.5 mm from the center of the vortex chamber. 14 is a line graph plotting the relationship between the length of the protrusion and the flow rate Q when the protrusion having the cross section of Shape 3 is positioned at an angular position of 90° and displaced by 3.5 mm, 5.5 mm, and 7.5 mm from the center of the vortex chamber in a numerical simulation using the vortex flow control valve shown in FIG. 13.14 is a bar graph showing a comparison of flow rate differences ΔQ when the length of the protrusion is changed from 0.5 mm to 3.5 mm at the position of each inlet flow channel, when the position of the inlet flow channel is changed with respect to the center of the vortex chamber under the condition that the protrusion having the cross section of Shape 1 is arranged at the center of the vortex chamber, in a numerical simulation using the vortex type flow control valve shown in Fig. 13. 15 is a bar graph showing a comparison of flow rate differences ΔQ when the length of the protrusion is changed from 0.5 mm to 3.5 mm at the position of each inlet flow channel, when the position of the inlet flow channel is changed with respect to the center of the vortex chamber under the condition that the protrusion having the cross section of Shape 1 is arranged at an angular position 90° and shifted by 5.5 mm from the center of the vortex chamber, in a numerical simulation using the vortex type flow control valve shown in Fig. 13. 14 is a bar graph showing a comparison of flow rate differences ΔQ when the length of the protrusion is changed from 0.5 mm to 3.5 mm at each inlet flow path position, when the position of the inlet flow path is changed relative to the center of the vortex chamber under the condition that the protrusion having the cross section of Shape 1 is positioned at a position offset by 7.5 mm from the center of the vortex chamber at an angular position of 90°, in a numerical simulation using the vortex flow control valve shown in Fig. 13. 15 is a bar graph showing a comparison of flow rate differences ΔQ when the length of the protrusion is changed from 0.5 mm to 3.5 mm at each outlet flow path position, when the position (distance) of the outlet flow path is changed relative to the center of the vortex chamber at an angular position of 90°, under the condition that the protrusion having the cross section of Shape 1 is positioned at a position offset by 7.5 mm from the center of the vortex chamber at an angular position of 90°, in a numerical simulation using the vortex flow control valve shown in Fig. 13. In a numerical simulation using the vortex flow control valve shown in Figure 13, a protrusion having a cross section of Shape 1 is positioned at an angle position 90°, displaced 7.5 mm from the center of the vortex chamber, and the position (distance) of the outlet flow path relative to the center of the vortex chamber is changed to an angle position of 180°. This is a bar graph comparing the flow rate difference ΔQ when the protrusion length is changed from 0.5 mm to 3.5 mm at each outlet flow path position.In a numerical simulation using the vortex flow control valve shown in Figure 13, a protrusion having a cross section of Shape 1 is positioned at a position offset by 7.5 mm from the center of the vortex chamber at an angular position of 90°, and this is a line graph plotting the relationship between the protrusion length and the flow rate Q when the position (distance) of the outlet flow path relative to the center of the vortex chamber at an angular position of 90° is changed to 0 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm, respectively.

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the overall configuration of a vortex flow control valve 11 according to a first embodiment of the present invention will be described with reference to FIGS.

[0022] The vortex flow control valve 11 includes a cylindrical peripheral wall 13 extending along a central axis, a first end wall 15 and a second end wall 17 provided at both ends of the peripheral wall 13 in the axial direction so as to face each other, an inlet flow path 19, an outlet flow path 21, a protrusion 23, and a drive unit 25 for driving the protrusion 23. The first end wall 15 and the second end wall 17 have the same shape and are provided so as to close the end of the peripheral wall 13 in the axial direction, and the space surrounded by the peripheral wall 13, the first end wall 15, and the second end wall 17 constitutes a vortex chamber 27. A vortex chamber central axis O extending to connect the center of the first end wall 15 and the center of the second end wall 17 coincides with the central axis of the peripheral wall 13. In this specification, the centers of the first end wall 15 and the second end wall 17 refer to the centers of gravity of the first end wall 15 and the second end wall 17, respectively. In the illustrated embodiment, the first end wall 15 and the second end wall 17 are circular, and the peripheral side wall 13 is cylindrical. However, the shapes of the first end wall 15 and the second end wall 17 are not limited to circular, and can be any shape, such as an elliptical shape or a polygonal shape such as a triangular shape or a square shape, as long as a vortex flow can be generated in the vortex chamber 27.

[0023] The inlet passage 19 extends along an inlet passage central axis P1 perpendicular to the vortex chamber central axis O and opens to the peripheral side wall 13. The inlet passage central axis P1 extends so as to pass through the center of the cross section of the inlet passage 19. The outlet passage 21 extends from the vortex chamber 27 to the outside along an outlet passage central axis P2 parallel to the vortex chamber central axis O and opens to the first end wall 15 of the vortex chamber 27. The outlet passage central axis P2 extends so as to pass through the center of the cross section of the outlet passage 21. In the illustrated embodiment, both the inlet passage 19 and the outlet passage 21 are formed by circular pipes having circular cross sections. However, the cross sections of the inlet passage 19 and the outlet passage 21 are not limited to circular shapes and can also be polygonal shapes such as elliptical or rectangular. In the illustrated embodiment, the inlet passage 19 is formed by a straight circular pipe, but may have other shapes, such as a nozzle shape, as long as it can introduce fluid into the vortex chamber 27.

[0024] The inlet passage 19 is provided such that the inlet passage central axis P1 passes through an eccentric position away from the vortex chamber central axis O. Therefore, the fluid flowing in from the inlet passage 19 hits the circumferential side wall 13 in the vortex chamber 27 and flows along the circumferential side wall 13, generating a swirling flow. This vortex flow moves toward the outlet passage 21 and flows out from the outlet passage 21. To facilitate the generation of a swirling flow, the inlet passage 19 is preferably provided such that the fluid flowing into the vortex chamber 27 from the inlet passage 19 flows along the circumferential side wall 13. On the other hand, the outlet passage 21 can be provided at any position on the first end wall 15 as long as the fluid flowing into the vortex chamber 27 from the inlet passage 19 generates a vortex flow and then flows out from the outlet passage 21. In other words, the outlet passage 21 only needs to be provided such that the outlet passage central axis P2 extends through a position away from the inlet passage central axis P1 so that the fluid flowing into the vortex chamber 27 from the inlet passage 19 does not flow out from the outlet passage 21 as is.

[0025] In the illustrated embodiment, the inlet passage 19 extends in a tangential direction of the cylindrical circumferential side wall 13 and is connected to the circumferential side wall 13 so that the inlet passage central axis P1 is parallel to the tangent line, allowing the fluid to flow from the inlet passage 19 into the vortex chamber 27 in a direction substantially tangential to the circumferential side wall 13. The outlet passage 21 opens to the first end wall 15 and is provided so that the outlet passage central axis P2 passes through the center of the first end wall 15, i.e., so that the outlet passage central axis P2 extends on the vortex chamber central axis O. With this configuration, the fluid flowing in from the inlet passage 19 flows along the circumferential side wall 13 in the vortex chamber 27, generating a swirling flow, and then flows in a spiral pattern toward the outlet passage 21 as it gradually approaches the center.

[0026] The protrusion 23 is provided on the second end wall 17 so as to protrude into the vortex chamber 27 toward the first end wall 15. The protrusion 23 is driven by a drive unit 25 to move within the vortex chamber 27 along a movement axis extending parallel to the central axis O of the vortex chamber. By moving the protrusion 23 within the vortex chamber 27 using the drive unit 25, the distance (i.e., the gap) between the top of the protrusion 23 extending from the second end wall 17 and the opposing first end wall 15 can be changed. In the illustrated embodiment, a cylinder mechanism is used as the drive unit 25, which can change the protruding length of the protrusion 23 into the vortex chamber 27. However, the drive unit 25 is not limited to a cylinder mechanism. Any other suitable mechanism, such as an electric actuator, can be used as long as it can move the protrusion 23 within the vortex chamber 27 to change the distance (i.e., the gap) between the top of the protrusion 23 extending from the second end wall 17 and the opposing first end wall 15. The drive unit can be of various drive types, such as manual, air-driven, or electric.

[0027] The protrusion 23 is columnar, and the cross section of the protrusion 23 perpendicular to the axis of movement can be any shape. The cross section of the protrusion 23 can be, for example, circular, elliptical, polygonal, such as rectangular, triangular, or diamond, or plate-like. In the illustrated embodiment, the protrusion 23 is columnar with a circular cross section. The protrusion 23 can also be conical or polygonal pyramidal, and steps or grooves may be provided on the peripheral side of the columnar or pyramidal shape.

[0028] It is preferable that the protrusion 23 is disposed so that at least a portion of the protrusion 23 overlaps with an extension of the inlet flow path 19 into the vortex chamber 27 so that the swirling flow of the fluid that has flowed into the vortex chamber 27 from the inlet flow path 19 collides with the protrusion 23 more quickly. However, since a vortex is generated in the vortex chamber 27 as described above, unless the axis of movement of the protrusion 23 is disposed so as to extend on the outlet flow path central axis P2, that is, unless the protrusion 23 is disposed in a position facing the outlet flow path 21, the protrusion 23 will collide with the vortex in the vortex chamber 27. Therefore, the position of the protrusion 23 is not particularly limited as long as it is positioned away from the position facing the outlet flow path 21.

[0029] Next, the operation of the vortex flow control valve 11 of the present invention will be described with reference to FIGS.

[0030] As described above, the inlet passage 19 is provided so that the inlet passage central axis P1 passes through an eccentric position away from the vortex chamber central axis O. Therefore, when the protruding portion 23 does not protrude into the vortex chamber 27, the fluid that flows in from the inlet passage 19 generates a swirling flow in the vortex chamber 27, swirls, and flows toward the outlet passage 21 and out of the outlet passage 21, as shown in Fig. 6. On the other hand, when the protruding portion 23 protrudes into the vortex chamber 27, the fluid that can flow through the gap between the top of the protruding portion 23 and the first end wall 15 continues to swirl and maintains the vortex flow, as shown by the flow lines 29 in Figs. 4 and 5. Furthermore, as shown by streamlines 31 in FIGS. 4 and 5 , a fluid with a protrusion 23 on its streamline flows through the gap between the outer circumferential surface of the protrusion 23 and the peripheral sidewall 13, then curves sharply inward along the circumferential surface of the protrusion 23, or as shown by streamlines 33 in FIGS. 4 and 5 , flows along the inner outer circumferential surface of the protrusion 23, avoids the protrusion 23, then curves sharply inward, and takes a shortcut to the outlet flow passage 21. The fluid that flows from the inlet flow passage 19 into the vortex chamber 27, forms a vortex flow, flows toward the outlet flow passage 21, and then flows out of the outlet flow passage 21 generates a pressure loss according to the distance it flows. Therefore, when the protrusion 23 causes the fluid to take a shortcut as described above, the length of the streamline from the inlet flow passage 19 to the outlet flow passage 21 in the vortex chamber 27 becomes shorter, and the pressure loss decreases. As a result, the flow rate increases.

[0031] When the protrusion 23 is moved in a direction that brings the top of the protrusion 23 closer to the first end wall 15 and thereby reduces the gap between the top of the protrusion 23 and the first end wall 15, the proportion of fluid that flows via a shortcut to the outlet flow passage 21 increases, and as a result, the pressure loss of the fluid flowing from the inlet flow passage 19 to the outlet flow passage 21 as a whole decreases, and the flow rate of the fluid flowing out of the outlet flow passage 21 increases. That is, as shown in FIG. 8 , by moving the protrusion 23 in a direction that brings the top of the protrusion 23 closer to the first end wall 15 and thereby reducing the gap between the top of the protrusion 23 and the first end wall 15, the flow rate of the fluid flowing out of the outlet flow passage 21 can be increased. On the other hand, as shown in FIG. 7 , by moving the protrusion 23 in a direction that moves the top of the protrusion 23 away from the first end wall 15 and thereby increasing the gap between the top of the protrusion 23 and the first end wall 15, the flow rate of the fluid flowing out of the outlet flow passage 21 can be decreased. The inventors have discovered that by moving the protrusion 23 within the vortex chamber 27 so as to change the gap between the top of the protrusion 23 and the first end wall 15, it is possible to adjust the flow rate of the fluid flowing out of the outlet flow path 21 without providing an abutment portion at the point in contact with the target fluid, and to enable the valve to function as a flow rate control valve.

[0032] As described above, flow rate regulation by the protrusion 23 is possible if the fluid flowing in from the inlet flow passage 19 forms a vortex in the vortex chamber 27 and flows toward the outlet flow passage 21, the protrusion 23 is positioned to obstruct this vortex, and the degree to which the protrusion 23 obstructs the vortex can be changed by moving the protrusion 23 within the vortex chamber 27. Therefore, as long as a vortex can be generated in the vortex chamber 27, the shape of the vortex chamber 27 and the positions of the inlet flow passage 19 and the outlet flow passage 21 are not limited, and as long as the protrusion 23 obstructs the vortex, the position of the protrusion 23 is not limited. Furthermore, the cross-sectional shape of the protrusion 23 is not limited. In other words, the vortex-type flow control valve 11 according to the present invention allows for a wide range of configuration combinations.

[0033] For example, as in a second embodiment of a vortex flow control valve 11′ shown in FIG. 9 , the second end wall may be formed of a diaphragm 17′, the protrusion 23 may be supported within the vortex chamber 27 by the diaphragm 17′, and the protrusion 23 may be moved within the vortex chamber 27 by driving the diaphragm 17′ to change the distance between the top of the protrusion 23 and the first end wall 15. In this case, the diaphragm 17′ functions not only as the second end wall but also as a drive unit that drives the protrusion 23. Since it is sufficient for the diaphragm 17′ to support and move the protrusion 23, only a portion of the second end wall 17 may be formed as the diaphragm 17′, and the protrusion 23 may be supported within the vortex chamber 27 by the diaphragm 17′. In FIG. 9 , components common to those of the first embodiment shown in FIG. 1 are designated by the same reference numerals. The configuration of the vortex flow control valve 11' of the second embodiment is similar to that of the vortex flow control valve 11 of the first embodiment, except that the protrusion 23 is moved within the vortex chamber 27 by a diaphragm 17' instead of the drive unit 25, and the action of the vortex flow control valve 11' of the second embodiment is also similar to that of the vortex flow control valve 11 of the first embodiment, in that the flow rate is adjusted by changing the distance (gap) between the first end wall 15 and the top of the protrusion 23. Therefore, detailed explanation of the configuration and action will be omitted here.

[0034] Below, we will explain the relationship between the length of the protrusion 23, the position of the protrusion 23, the shape of the protrusion 23, the position of the inlet flow path 19, the position of the outlet flow path 21, etc., and the flow rate or the amount of change in flow rate of the fluid, which is obtained by experiment or numerical simulation in a vortex flow control valve having a configuration similar to that of the vortex flow control valve 11 of the first embodiment shown in Fig. 1. In the following explanation, for ease of understanding, the same reference numerals as those in the vortex flow control valve 11 will be used for each component of the vortex flow control valve used in the experiment or numerical simulation.

[0035] First, the relationship between the length of the protrusion 23 and the fluid flow rate Q obtained through an experiment using an actually manufactured vortex flow control valve 11 will be described. As shown in Figures 10A and 10B , in the vortex flow control valve 11 used in the experiment, the vortex chamber 27 has a cylindrical shape with a diameter of 20 mm and a height of 4 mm. The inlet flow passage 19, which has a circular pipe shape with a diameter of 4 mm and a length of 15 mm, is connected to the peripheral side wall 13 so as to extend tangentially. The outlet flow passage 21, which has a circular pipe shape with a diameter of 4 mm and a length of 10 mm, extends along the vortex chamber central axis O and is connected to the first end wall 15 so that the outlet flow passage central axis P2 passes through the center of the first end wall 15. The protrusion 23 has a cylindrical shape with a diameter of 5 mm and is positioned at a position offset by 7 mm from the center of the vortex chamber 27 toward the inlet flow passage 19 in a direction perpendicular to the inlet flow passage central axis P1 of the inlet flow passage 19. As shown in FIG. 11 , the pressure regulating valve 35 arranged upstream of the vortex type flow control valve 11 is used to adjust the differential pressure between the upstream pressure PU and downstream pressure PD of the vortex type flow control valve 11, and while changing the length of the protruding portion 23 of the vortex type flow control valve 11, the flow rate is measured by a flow meter 37 arranged upstream of the vortex type flow control valve 11 (more specifically, downstream of the pressure regulating valve 35), and the upstream pressure PU and downstream pressure PD are measured by an upstream pressure meter 39 and a downstream pressure meter 41 arranged upstream and downstream of the vortex type flow control valve 11, respectively.

[0036] FIG. 12 is a graph plotting the experimentally obtained relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min). In FIG. 12, the symbol "●" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min) when the differential pressure between the upstream pressure PU and the downstream pressure PD is 0.05 MPa, the symbol "▲" indicates the relationship when the differential pressure is 0.1 MPa, and the symbol "■" indicates the relationship when the differential pressure is 0.2 MPa. As can be seen from FIG. 12, a correlation is established between the length of the protrusion 23 and the flow rate Q under all differential pressure conditions, and the longer the protrusion 23, the greater the flow rate Q. Therefore, it was confirmed that the flow rate Q can be adjusted and controlled by changing the length of the protrusion 23. It was also confirmed that the flow rate Q increases as the differential pressure increases.

[0037] Next, the results of a numerical simulation (hereinafter simply referred to as a simulation) will be described. In the following description, unless otherwise specified, the simulation was performed under the following conditions: vortex chamber 27 has a cylindrical shape with a diameter of 20 mm and a height of 4 mm; inlet passage 19, which has a circular tubular shape and a diameter of 4 mm, is connected to peripheral side wall 13 so that inlet passage central axis P1 passes through a position 7.5 mm away from the center of vortex chamber 27 and the right end of inlet passage 19 in the figure is located 15 mm away from a line passing through the center of vortex chamber 27 and perpendicular to inlet passage central axis P1; and outlet passage 21, which has a circular tubular shape and a diameter of 4 mm and a length of 10 mm, extends along vortex chamber central axis O and is connected to first end wall 15 so that outlet passage central axis P2 passes through the center of first end wall 15.

[0038] First, the influence of the position of the protrusion 23 in the vortex chamber 27 was confirmed by simulation. Here, the protrusion 23 had a cylindrical shape with a diameter of 4 mm, and was disposed so that its central axis was displaced by various distances (3.5 mm, 5.5 mm, 7.5 mm) from the center of the vortex chamber 27 toward the peripheral side wall 13 at various angular positions (0°, 45°, 90°, 135°, 180°, 270°). The length of the protrusion was changed in the range from 0.5 mm to 3.5 mm, and the amount of change in the flow rate Q (hereinafter referred to as the "flow rate difference ΔQ") was obtained. As shown in Figure 13, the "angular position" of protrusion 23 is defined as the angle formed by an axis extending from the center of vortex chamber 27 through the center of protrusion 23 counterclockwise around the center of vortex chamber 27 with the axis of 0°, where the direction of the axis is parallel to inlet flow path central axis P1 and passes through the center of vortex chamber 27 toward the side closer to inlet flow path 19 is defined as 0°.

[0039] 14 is a graph plotting the relationship between the angular position (°) of the protrusion 23 and the flow rate difference ΔQ (L / min) obtained when the length of the protrusion 23 was changed from 0.5 mm to 3.5 mm in a simulation. In FIG. 14, the symbol "■" indicates the relationship between the angular position (°) of the protrusion 23 and the flow rate difference ΔQ (L / min) when the central axis of the protrusion 23 is positioned 3.5 mm eccentric from the center of the vortex chamber 27, the symbol "▲" indicates the relationship when the central axis of the protrusion 23 is positioned 5.5 mm eccentric from the center of the vortex chamber 27, and the symbol "●" indicates the relationship between the angular position (°) of the protrusion 23 and the flow rate difference ΔQ (L / min) when the central axis of the protrusion 23 is positioned 7.5 mm eccentric from the center of the vortex chamber 27.

[0040] 14 shows that under the condition that the inlet flow passage 19 is connected to the circumferential side wall 13 so as to extend in a direction substantially tangential to the circumferential side wall 13 and the outlet flow passage 21 is connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, the flow rate Q can be changed and a flow rate difference ΔQ can be generated by changing the length of the protrusion 23, regardless of the angular position of the protrusion 23 and the eccentric distance of the protrusion 23 from the center of the vortex chamber 27. Furthermore, it can be seen that the farther the protrusion 23 is disposed from the center of the vortex chamber 27, i.e., the closer the protrusion 23 is disposed to the circumferential side wall 13 of the vortex chamber 27, the wider the range of flow rate adjustment becomes, and particularly when the protrusion 23 is disposed at an angular position in the range of 90° to 180°, the wider the range of flow rate adjustment becomes. This is presumably because, when a fluid flows from the inlet flow passage 19 along the circumferential side wall 13 of the vortex chamber 27 and becomes a vortex, the closer the protrusion 23 is positioned to the circumferential side wall 13 and the closer it is to the starting point of the vortex of the fluid flowing in from the inlet flow passage 19, the easier it is to achieve the effect of the vortex taking a shortcut toward the outlet flow passage 21.

[0041] 15 and 16 are line graphs plotting the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) obtained when the protrusion 23 was provided at angular positions of 90° and 180° and the length of the protrusion 23 was changed from 0.5 mm to 3.5 mm in a simulation. In Fig. 15, the symbol "■" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the central axis of the protrusion 23 was positioned 3.5 mm eccentric from the center of the vortex chamber 27 at the angular position of 90°, the symbol "▲" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the central axis of the protrusion 23 was positioned 5.5 mm eccentric from the center of the vortex chamber 27 at the angular position of 90°, and the symbol "●" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the central axis of the protrusion 23 was positioned 7.5 mm eccentric from the center of the vortex chamber 27 at the angular position of 90°. Also, in Figure 16, the symbol "■" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the central axis of the protrusion 23 is positioned 3.5 mm eccentric from the center of the vortex chamber 27 at an angular position of 180°, the symbol "▲" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the central axis of the protrusion 23 is positioned 5.5 mm eccentric from the center of the vortex chamber 27 at an angular position of 180°, and the symbol "●" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the central axis of the protrusion 23 is positioned 7.5 mm eccentric from the center of the vortex chamber 27 at an angular position of 180°.

[0042] 15 and 16 show that, regardless of whether the protrusion 23 is provided at an angular position of 90° or 180°, the flow rate Q increases as the length of the protrusion 23 increases and as the protrusion 23 is disposed farther from the center of the vortex chamber 27. In particular, when the protrusion 23 is disposed 5.5 mm or more away from the center of the vortex chamber 27, the correlation between the length of the protrusion 23 and the flow rate Q increases. Furthermore, although not shown here, even when the protrusion 23 is disposed at angular positions of 0°, 45°, 135°, and 270°, the flow rate Q increases as the length of the protrusion 23 increases, confirming that there is a correlation between the length of the protrusion 23 and the flow rate Q. Therefore, under the condition that the inlet flow passage 19 is connected to the circumferential side wall 13 so as to extend in a direction approximately tangential to the circumferential side wall 13, and the outlet flow passage 21 is connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, it is possible to change the flow rate Q by changing the length of the protrusion 23, regardless of the position of the protrusion 23, and thereby adjust and control the flow rate Q.

[0043] Next, the influence of the cross-sectional shape of the protrusion 23 was confirmed by simulation. Here, the simulation was performed for the cases where the protrusion 23 had three cross-sectional shapes shown in FIGS. 17A to 17C , namely, cross-sectional shape 1, cross-sectional shape 2, and cross-sectional shape 3. Cross-sectional shape 1 was a circle with a diameter of 4 mm as shown in FIG. 17A , cross-sectional shape 2 was a diamond with a diagonal length of 4 mm as shown in FIG. 17B , and cross-sectional shape 3 was a square with sides of 4 mm as shown in FIG. 17C . In the case of cross-sectional shape 2, the protrusion 23 was positioned so that the vortex flow first hit the corners of the diamond shape, and in the case of cross-sectional shape 3, the protrusion 23 was positioned so that the vortex flow was received by the square surface.

[0044] 18 and 19 are bar graphs comparing the flow rate difference ΔQ (L / min) obtained by simulation when the length of the protrusion 23 is changed from 0.5 mm to 3.5 mm for each cross-sectional shape of the protrusion 23. Fig. 18 shows the results obtained when the protrusion 23 is provided so that its central axis is positioned at an angular position of 90° and 3.5 mm eccentric from the center of the vortex chamber 27, and Fig. 19 shows the results obtained when the protrusion 23 is provided so that its central axis is positioned at an angular position of 90° and 7.5 mm eccentric from the center of the vortex chamber 27.

[0045] 18 and 19 show that under the condition that the inlet flow passage 19 is connected to the circumferential side wall 13 so as to extend in a direction substantially tangential to the circumferential side wall 13 and the outlet flow passage 21 is connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, the flow rate Q can be changed and a flow rate difference ΔQ can be generated by changing the length of the protrusion 23, regardless of the cross-sectional shape of the protrusion 23. Furthermore, a comparison of the flow rate difference ΔQ depending on the position of the protrusion 23, including the result when the protrusion 23 (not shown) is positioned at an angular position of 90°, eccentric by 5.5 mm from the center of the vortex chamber 27, shows that the farther the protrusion 23 is positioned from the center of the vortex chamber 27, i.e., the closer the protrusion 23 is positioned to the circumferential side wall 13 of the vortex chamber 27, the wider the range of flow rate adjustment becomes. This is presumably because, as described above, when the fluid flows from the inlet passage 19 along the peripheral side wall 13 of the vortex chamber 27 and becomes a vortex, the closer the protrusion 23 is positioned to the peripheral side wall 13 and the closer it is to the starting point of the vortex of the fluid flowing in from the inlet passage 19, the more likely it is that the vortex will have the effect of shortcutting towards the outlet passage 21. Furthermore, a comparison of the flow rate difference ΔQ depending on the position of the protrusion 23, including the result when the protrusion 23 (not shown) is positioned at an angular position of 90°, eccentric by 5.5 mm from the center of the vortex chamber 27, shows that the flow rate difference ΔQ is larger for Shape 2 (diamond-shaped cross section) than for Shape 1 (circular cross section), and that the flow rate difference ΔQ is even larger for Shape 3 (square cross section) than for Shape 2. This is presumably because, compared with a circular cross-section protrusion 23, a diamond-shaped cross-section protrusion 23 is arranged so that its corners hit the vortex first, or a square cross-section protrusion 23 is arranged so that its surface receives the vortex, which makes it easier to obtain the effect of shortcutting the vortex toward the outlet flow path 21. Furthermore, even with a rectangular or plate-shaped protrusion, it is presumed that if the vortex hits the surface, it can be similarly made to shortcut the vortex toward the outlet flow path 21, thereby achieving the effect of increasing the flow rate difference ΔQ.

[0046] 20 is a line graph plotting the relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min) obtained in a simulation in which a protrusion 23 having a cross section of Shape 3 is provided at an angular position of 90° and the length of the protrusion 23 is changed from 0.5 mm to 3.5 mm. In FIG. 20, the symbol "■" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min) when the central axis of the protrusion 23 is positioned 3.5 mm eccentric from the center of the vortex chamber 27 at an angular position of 90°, the symbol "▲" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min) when the central axis of the protrusion 23 is positioned 5.5 mm eccentric from the center of the vortex chamber 27 at an angular position of 90°, and the symbol "●" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min) when the central axis of the protrusion 23 is positioned 7.5 mm eccentric from the center of the vortex chamber 27 at an angular position of 90°.

[0047] 20 shows that, even when the cross-sectional shape of the protrusion 23 is square, the flow rate Q increases as the length of the protrusion 23 increases and as the protrusion 23 is disposed farther from the center of the vortex chamber 27, just as when the cross-sectional shape of the protrusion 23 is circular. Although not shown here, even when the cross-sectional shape of the protrusion 23 is diamond-shaped, the flow rate Q similarly increases as the length of the protrusion 23 increases and as the protrusion 23 is disposed farther from the center of the vortex chamber 27. Therefore, under the condition that the inlet flow path 19 is connected to the circumferential side wall 13 so as to extend in a direction substantially tangential to the circumferential side wall 13 and the outlet flow path 21 is connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, the flow rate Q can be changed by changing the length of the protrusion 23, and the flow rate Q can be adjusted and controlled, regardless of the cross-sectional shape of the protrusion 23.

[0048] Next, the influence of the position of the inlet passage 19 on the vortex chamber 27 was confirmed by simulation. The position of the inlet passage 19 was defined as the ratio (%) of the distance between the center of the vortex chamber 27 and the central axis P1 of the inlet passage 19 to the value obtained by dividing the difference between the diameter of the cylindrical vortex chamber 27 and the diameter of the circular tubular inlet passage 19 by 2. This is because the inlet passage 19 can only be positioned as close to the circumferential sidewall 13 as possible, with its central axis P1 separated from the circumferential sidewall 13 by the radius of the inlet passage 19. Here, the simulation was performed under the conditions that a cylindrical protrusion 23 with a diameter of 4 mm was provided at an angular position of 90°, and the outlet passage 21 was connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, and the position of the inlet passage 19 relative to the outlet passage 21 was 0%, 25%, 50%, 75%, 94%, and 100%.

[0049] 21 to 23 are bar graphs comparing the flow rate difference ΔQ (L / min) obtained by varying the length of the protrusion 23 from 0.5 mm to 3.5 mm when the position of the inlet passage 19 relative to the outlet passage 21 is changed to 0%, 25%, 50%, 75%, 94%, and 100% for various positions of the protrusion 23. FIG. 21 shows the results obtained when the protrusion 23 is provided so that its central axis is located at the center of the vortex chamber 27. FIG. 22 shows the results obtained when the protrusion 23 is provided so that its central axis is located at an angular position of 90° and 5.5 mm eccentric from the center of the vortex chamber 27. FIG. 23 shows the results obtained when the protrusion 23 is provided so that its central axis is located at an angular position of 90° and 7.5 mm eccentric from the center of the vortex chamber 27. In Figures 21 to 23, the open bar graphs indicate that the flow rate is relatively high when the protrusion 23 is short and that the flow rate is relatively low when the protrusion 23 is long, and the solid black bar graphs indicate that the flow rate is relatively low when the protrusion 23 is short and that the flow rate is relatively high when the protrusion 23 is long.

[0050] 21 to 23 , under the condition that outlet passage 21 is connected to first end wall 15 so as to extend from the center of vortex chamber 27, if protrusion 23 is located eccentrically from the center of vortex chamber 27, it is possible to change the flow rate Q and generate a significant flow rate difference ΔQ by changing the length of protrusion 23, regardless of the position of inlet passage 19, except when inlet passage central axis P1 of inlet passage 19 passes through the center of vortex chamber 27 (i.e., when the position of inlet passage 19 is 0%). This is presumably because, if inlet passage central axis P1 of inlet passage 19 does not pass through the center of vortex chamber 27, the fluid flowing in from inlet passage 19 will generate a vortex flow within vortex chamber 27. Therefore, by providing protrusion 23 at a position eccentric to the center of vortex chamber 27, protrusion 23 has the effect of changing the direction of the vortex flow and causing the fluid to take a shortcut to outlet passage 21. Therefore, in order to adjust the flow rate Q by adjusting the length of the protrusion 23, the inlet flow path 19 must be arranged so that the inlet flow path central axis P1 does not pass through the center of the vortex chamber 27. On the other hand, as can be seen from FIG. 21 , when the protrusion 23 is arranged at the center of the vortex chamber 27 (i.e., when the protrusion 23 is arranged at an angular position of 90° and eccentric by a distance of 0 mm from the center of the vortex chamber 27), the longer the protrusion 23, the lower the flow rate, regardless of the position of the protrusion 23. This is presumably because, under the condition that the outlet flow path 21 is connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, if the protrusion 23 is arranged at the center of the vortex chamber 27, the protrusion 23 will be positioned opposite the outlet flow path 21, and the longer the protrusion 23, the smaller the flow path area for the fluid flowing into the outlet flow path 21. Similarly, when the protrusion 23 overlaps even partially with the outlet flow path 21 when the vortex chamber 27 is viewed in the direction of the vortex chamber central axis O, the longer the protrusion 23, the lower the flow rate.

[0051] 22 and 23, it was found that, under the condition that the outlet passage 21 is connected to the first end wall 15 so as to extend from the center of the vortex chamber 27, when the protrusion 23 is provided at a position eccentric by 7.5 mm from the center of the vortex chamber 27, i.e., when the protrusion 23 is provided at a position substantially adjacent to the circumferential side wall 13 of the vortex chamber 27, a wider range of flow rate adjustment is possible by providing the inlet passage 19 at a position between 50% and 100%, i.e., by providing the inlet passage 19 so that the inlet passage central axis P1 is closer to the circumferential side wall 13 than to the center of the vortex chamber 27. This is presumably because the shortcut effect of the vortex flow is greater when the protrusion 23 is provided near the circumferential side wall 13 of the vortex chamber 27 and the inlet passage central axis P1 of the inlet passage 19 is located near the circumferential side wall 13 of the vortex chamber 27.

[0052] Finally, the influence of the position of the outlet passage 21 on the vortex chamber 27 was confirmed by simulation. As shown in FIG. 13 , the position of the outlet passage 21 was defined by an angular position defined similarly to the angular position of the protrusion 23 and a distance X from the center of the vortex chamber 27. For example, the position of the outlet passage 21 indicated by the two-dot chain line in FIG. 13 is represented as a position at an angular position of 0° and a distance X. In the simulation, the inlet passage 19 was provided so that the inlet passage central axis P1 was located at a position 8 mm away from the center of the vortex chamber 27, and the cylindrical protrusion 23 with a diameter of 4 mm was located at an angular position of 90°, eccentric from the center of the vortex chamber 27 by a distance of 7.5 mm.

[0053] 24 and 25 are bar graphs comparing the flow rate difference ΔQ (L / min) obtained by varying the length of the protrusion from 0.5 mm to 3.5 mm when the distance X of the outlet passage 21 from the center of the vortex chamber 27 is 0 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm for different angular positions of the outlet passage 21. Fig. 24 shows the results obtained when the outlet passage 21 is located at an angular position of 90°, and Fig. 25 shows the results obtained when the outlet passage 21 is located at an angular position of 180°.

[0054] 24 and 25 show that under the conditions where the inlet flow passage 19 is provided so that the inlet flow passage central axis P1 is located 8 mm away from the center of the vortex chamber 27 and the cylindrical protrusion 23 with a diameter of 4 mm is provided at an angular position of 90°, 7.5 mm eccentric from the center of the vortex chamber 27, the flow rate Q can be changed and a flow rate difference ΔQ can be generated by changing the length of the protrusion 23, regardless of the position of the outlet flow passage 21. In other words, the flow rate Q can be adjusted by changing the length of the protrusion 23, regardless of the outlet flow passage 21. Furthermore, a comparison of the flow rate difference ΔQ depending on the position of the outlet flow passage 21, including results when the outlet flow passage 21 is provided at an angular position of 0° and an angular position of 270° (not shown), shows that a wider range of flow rate adjustment is possible when the outlet flow passage 21 is provided at an angular position of 90°, eccentric from the center of the vortex chamber 27. This is presumably because the protrusion 23 is also positioned at an angle of 90°, making it easier for the vortex flow bent by the protrusion 23 to reach the outlet flow path 21 more quickly, making it easier to achieve the effect of shortcutting the vortex flow toward the outlet flow path 21.

[0055] Figure 26 is a line graph plotting the relationship between the length (mm) of the protrusion 23 and the flow rate Q (L / min) obtained when the length of the protrusion 23 was changed from 0.5 mm to 3.5 mm in a simulation in which the outlet flow path 21 was provided eccentrically from the center of the vortex chamber 27 at an angular position of 90°. In Figure 26, the symbol "●" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the outlet flow path 21 is located at the center of the vortex chamber 27, the symbol "■" indicates the relationship when the outlet flow path 21 is located at an angular position of 90° and 0.25 mm eccentric from the center of the vortex chamber 27, the symbol "◆" indicates the relationship when the outlet flow path 21 is located at an angular position of 90° and 0.5 mm eccentric from the center of the vortex chamber 27, the symbol "▲" indicates the relationship when the outlet flow path 21 is located at an angular position of 90° and 1 mm eccentric from the center of the vortex chamber 27, and the symbol "*" indicates the relationship between the length (mm) of the protrusion 23 and the flow rate (L / min) when the outlet flow path 21 is located at an angular position of 90° and 2 mm eccentric from the center of the vortex chamber 27.

[0056] 26 shows that the flow rate Q increases as the length of the protrusion 23 increases, regardless of the distance from the center of the vortex chamber 27 to the outlet flow passage 21. Therefore, under the following conditions: the inlet flow passage 19 is provided so that the inlet flow passage central axis P1 is located 8 mm away from the center of the vortex chamber 27; the cylindrical protrusion 23 with a diameter of 4 mm is located at an angular position 90°, 7.5 mm eccentric from the center of the vortex chamber 27; and the outlet flow passage 21 is located at an angular position 90°, the flow rate Q can be adjusted and controlled by changing the length of the protrusion 23, regardless of the position of the outlet flow passage 21 from the center of the vortex chamber 27. Also, FIG. 26 shows that the flow rate Q increases as the outlet flow passage 21 is located farther from the center of the vortex chamber 27. Therefore, to obtain a larger flow rate, it is preferable to locate the outlet flow passage 21 as far away from the center of the vortex chamber 27 as possible.

[0057] Although the vortex flow control valve according to the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to the illustrated embodiment. For example, while the illustrated embodiment employs a cylindrical vortex chamber 27, an elliptical or polygonal cylindrical vortex chamber may also be employed as long as a vortex can be generated within the vortex chamber 27. Furthermore, since the flow rate Q can be changed by changing the gap between the top of the protrusion 23 and the opposing end wall, the protrusion 23 may be provided on the first end wall 15 rather than the second end wall 17.

[0058] REFERENCE SIGNS LIST 11 vortex flow control valve 13 peripheral side wall 15 first end wall 17 second end wall 17' diaphragm 19 inlet flow passage 21 outlet flow passage 23 protrusion 25 drive portion 27 vortex chamber

Claims

1. A vortex flow control valve comprising: a vortex chamber defined by a cylindrical peripheral side wall and first and second end walls provided at both ends of the peripheral side wall and facing each other; an inlet flow path extending along the central axis of an inlet flow path and opening onto the peripheral side wall; and an outlet flow path extending along the central axis of an outlet flow path and opening onto the first end wall, wherein a fluid flowing in from the inlet flow path forms a vortex within the vortex chamber and flows out from the outlet flow path; wherein the inlet flow path is arranged so that the central axis of the inlet flow path passes through a position away from the central axis of the vortex chamber which connects the center of the first end wall and the center of the second end wall; and the vortex flow control valve further comprises a protrusion protruding into the vortex chamber from one of the first end wall and the second end wall; and a drive unit which moves the protrusion toward and away from the other of the first end wall and the second end wall within the vortex chamber, wherein the flow rate of the fluid flowing out of the outlet flow path is adjusted by the movement of the protrusion.

2. A vortex flow control valve as set forth in claim 1, wherein said protrusion is provided at a position eccentric to the central axis of said vortex chamber.

3. A vortex flow control valve as set forth in claim 2, wherein the protrusion is provided so that at least a portion of the protrusion overlaps an extension of the inlet flow path into the vortex chamber.

4. The vortex flow control valve according to claim 1, wherein the first end wall and the second end wall are circular or elliptical.

5. A vortex-type flow control valve as described in any one of claims 1 to 4, wherein the outlet flow path is arranged so that the central axis of the outlet flow path extends through a position away from the central axis of the inlet flow path.

6. A vortex flow control valve as set forth in claim 5, wherein the outlet flow passage is provided so that the axis of the outlet flow passage extends on the central axis of the vortex chamber.

7. A vortex-type flow control valve as described in claim 5, wherein the outlet flow passage is arranged so that the outlet flow passage axis extends through a position offset from the central axis of the vortex chamber toward the central axis of the inlet flow passage.

8. The vortex type flow control valve according to claim 5, wherein the protrusion is provided at a position offset from the central axis of the outlet flow passage.

9. The vortex type flow control valve according to claim 5, wherein the protrusion has a circular or elliptical cross section.

10. The vortex type flow control valve according to claim 5, wherein the drive unit drives the protrusion to change the protrusion length of the protrusion into the vortex chamber.

11. The vortex-type flow control valve according to claim 5, wherein said protrusion is provided on said second end wall.

12. The vortex-type flow control valve according to claim 11, wherein the second end wall comprises a diaphragm, the protrusion is attached to the diaphragm, and the drive portion drives the protrusion via the diaphragm.