JP2023117677A - Waste liquid selector valve - Google Patents

Abstract

To provide a waste liquid selector valve which enables fluid to flow more easily.SOLUTION: A waste liquid selector valve 11 includes: a valve body 13 in which a main passage 15 extending linearly along a main passage axis L is formed; and multiple valve mechanism parts 17 provided on the main passage 15. Each valve mechanism part 17 includes: a valve chamber 21 provided on the main passage 15; and a valve body 23 which is disposed in the valve chamber and has a taper part 23b at a tip. The valve body 13 is formed with: a branch passage 27 extending in a direction of a branch passage axis M perpendicular to the main passage axis L; and a contraction part 41 which extends between the valve chamber 21 and the branch passage 27 and has a smooth inner peripheral surface which narrows from the valve chamber 21 to the branch passage 27. The valve body 23 is reciprocated in a direction of the branch passage axis M to move an outer peripheral surface of the taper part 23b of the valve body 23 close to or away from the inner peripheral surface of the contraction part 41 and thereby open or close the valve mechanism part 17.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a waste liquid switching valve that is used in piping lines in various industrial fields such as chemical plants, semiconductor manufacturing, foodstuffs, and biotechnology, and that can discharge fluid by switching a waste liquid line.

In the cleaning process of semiconductor manufacturing, a plurality of liquids such as chemical solutions and pure water are switched and supplied to a cleaning tank, and then discharged from the tank of the cleaning tank through a discharge line. From the viewpoint of waste liquid treatment, the used liquid is preferably recovered by switching the discharge line for each type. For this reason, it is conceivable to use a switching valve in the discharge line. For example, as the switching valve, a channel switching device as disclosed in Patent Document 1 or Patent Document 2 can be used. In addition, in the semiconductor cleaning process, in addition to batch-type cleaning equipment that cleans multiple wafers simultaneously in a single cleaning tank, cleaning solutions suitable for the materials used for each wafer can be used to support small-lot, high-mix production. In order to do this, a single-wafer cleaning apparatus, which cleans each wafer in a single cleaning tank, has been increasingly adopted.

Japanese Patent No. 4944049 Japanese Patent No. 5039604

In the single-wafer type cleaning apparatus, cleaning tanks are arranged in multiple stages so that processing can be performed in parallel in order to increase the throughput. Moreover, the waste liquid from the cleaning tank of the cleaning apparatus is generally discharged by utilizing the difference in the lift of the waste liquid line. For this reason, if the number of stages is increased while suppressing an increase in the size of the entire apparatus, the difference in the lift of each waste liquid line that can be secured from each cleaning tank to the switching valve will be reduced. However, the conventional common channel switching device has a large pressure loss, a small so-called capacity coefficient Cv, and a small discharge flow rate of the waste liquid. For this reason, there is a problem that the waste liquid tank of the cleaning tank tends to overflow.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the problems of the prior art and to provide a waste fluid switching valve that facilitates fluid flow.

In view of the above objects, the present invention provides a waste liquid switching valve that includes a valve body in which a main flow path extending linearly along the axis of the main flow path is formed, and a plurality of valve mechanisms provided on the main flow path. wherein each valve mechanism includes a valve chamber provided on the main flow passage, and a valve element disposed in the valve chamber and having a tapered portion at a distal end thereof; and a smooth inner peripheral surface extending between the valve chamber and the branch channel and tapering from the valve chamber toward the branch channel. A narrowed portion is formed, and the valve body is reciprocated in the direction of the branch flow path axis to bring the outer peripheral surface of the tapered portion of the valve body into contact with and separate from the inner peripheral surface of the narrowed portion. A waste liquid selector valve adapted to open and close a valve mechanism is provided.

In the waste liquid switching valve, the tapered portion at the tip of the valve body is provided on the smooth inner peripheral surface of the narrowed portion provided between the valve chamber and the branch flow path so as to taper from the valve chamber toward the branch flow path. The valve mechanism is opened and closed by bringing the outer peripheral surfaces of the valves into contact with each other. Here, "smooth" means that the inner peripheral surface is not provided with protrusions, corners, or the like. When the tapered portion of the valve body is brought into contact with and separated from the corner formed at the boundary between the valve chamber and the branch flow path extending in the direction of the axis of the branch flow path perpendicular to the axis of the main flow path, the valve mechanism section When the valve is open, the flow passage area between the tapered portion and the corner portion of the valve body is rapidly narrowed and then widened rapidly. On the other hand, when the valve mechanism portion of the waste liquid switching valve is open, the fluid flows between the inner peripheral surface of the throttle portion and the outer peripheral surface of the tapered portion of the valve body, and the flow path area changes gradually. Therefore, the change in the flow velocity of the fluid becomes gentle, and the pressure loss becomes small. Further, since the tapered portion of the valve body contacts and separates from the smooth inner peripheral surface of the throttle portion, the flow of fluid between the throttle portion and the tapered portion is not hindered by projections or the like. As a result, the pressure loss of the fluid from the valve chamber to the branch channel can be reduced, and the fluid can easily flow from the valve chamber to the branch channel. Furthermore, when the valve mechanism is in the closed state, the outer peripheral surface of the tapered portion of the valve body and the inner peripheral surface of the throttle portion abut within the throttle portion. Therefore, the volume of the valve body accommodated in the throttle portion is increased, and the volume of the portion of the valve body protruding on the extension of the main flow path in the valve chamber can be reduced. As a result, when the fluid flowing through the main channel passes through the closed valve mechanism, the valve element prevents the fluid from interfering with the flow of the fluid, allowing the fluid to flow through the waste liquid switching valve and into the branch flow channel. easier.

In the above waste liquid switching valve, it is preferable that the inner peripheral surface of the throttle portion is a smooth curved surface curved in a convex shape.

In addition, the valve chamber is formed so as to extend further than the main flow path in a direction of a width axis perpendicular to the main flow path axis and the branch flow path axis. The length in the direction is preferably greater than the length in the direction of the branch channel axis, and the cross section of the main channel has a rectangular shape that is longer in the direction of the width axis than in the direction of the branch channel axis. is more preferred.

Furthermore, it is preferable that the main flow path is connected to an external flow path via a connection path, and that the cross section of the main flow path is larger than the cross section of the connection path in the direction of the width axis. However, it is more preferable to include an enlarged diameter portion that is tapered and expanded in the direction of the width axis from the external flow channel toward the main flow channel.

In the waste liquid switching valve, a connecting portion between the main flow path and the valve chamber may be chamfered.

Further, in the waste liquid switching valve, the outer peripheral surface of the tapered portion of the valve body is positioned farther from the branch flow path than the front inclined surface located on the tip side and the front inclined surface, and and a rear-side inclined surface forming an angle with respect to the branch channel axis that is larger than the front-side inclined surface, and the rear-side inclined surface may contact and separate from the inner peripheral surface of the narrowed portion. .

As one embodiment, the main flow path extends between a first end and a second end connected to the connection path, and the plurality of valve chambers are at least in the first It can be provided at the end and the second end.

According to the present invention, the pressure loss between the valve chamber and the branch channel can be reduced, and the fluid can easily flow between the valve chamber and the branch channel. In addition, when the fluid flowing through the main flow path passes through the valve mechanism in the closed state, it is possible to prevent the flow of the fluid from being obstructed, and the fluid can easily flow to the branch flow path through the waste liquid switching valve. Therefore, it becomes easier for the fluid to pass through the waste liquid switching valve. As a result, even when a waste liquid switching valve is used in a waste liquid line with a small head difference, it is possible to suppress a decrease in the flow rate and ensure a sufficient waste liquid flow rate.

1 is a longitudinal sectional view showing the overall configuration of a waste liquid switching valve according to the present invention; FIG. FIG. 2 is a perspective view showing a state in which a valve body of the waste liquid switching valve shown in FIG. 1 is cut; 2 is a cross-sectional view of the valve body of the waste liquid switching valve shown in FIG. 1 as viewed from above in FIG. 1; FIG. FIG. 4 is a cross-sectional view of the valve body of the waste liquid switching valve taken along line AA in FIG. 3; FIG. 5 is an enlarged cross-sectional view showing an enlarged valve chamber portion of a valve body in a modified form of the waste liquid switching valve according to the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a waste liquid switching valve according to the present invention will be described with reference to the drawings.
First, referring to FIG. 1, the overall configuration of the waste liquid switching valve 11 will be described.

The waste liquid switching valve 11 includes a valve body 13 in which a main flow path 15 extending linearly along the main flow path axis L is formed, and a plurality of valve mechanisms 17 provided on the main flow path 15 . , one end of the main flow passage 15 in the direction of the main flow passage axis L is connected to the external flow passage via a connecting passage 19 . In the illustrated embodiment, the waste liquid switching valve 11 has three valve mechanism portions 17A, 17B, and 17C, but may have two or four or more valve mechanism portions 17. FIG.

The valve mechanism sections 17A, 17B, and 17C basically have the same configuration, and in the drawing, common reference numerals are given to configurations common to the respective valve mechanism sections 17A, 17B, and 17C. When referring to the configuration of a particular one of the valve mechanisms 17A, 17B and 17C, the reference numerals are denoted by A, B and C correspondingly, and each valve rather than the specific valve mechanisms 17A, 17B and 17C The symbols A, B, and C are not attached when referring to the configuration common to the mechanism section 17 .

Each valve mechanism portion 17 is composed of a valve chamber 21 provided on the main flow passage 15, a valve body 23 arranged in the valve chamber 21, and a driving portion 25 for driving the valve body 23. . Each valve chamber 21 has a substantially cylindrical inner peripheral surface and extends in the direction of the branch flow channel axis M perpendicular to the main flow channel axis L. provided at intervals. In the illustrated embodiment, the valve chamber 21C of the valve mechanism portion 17C is provided at one end of the main flow path 15 connected to the connection path 19 in the direction of the main flow path axis L, and the other end of the main flow path 15 is provided. A valve chamber 21A of the valve mechanism portion 17A is provided in the portion, and a valve chamber 21B of the valve mechanism portion 17B is provided on the main flow path 15 between the valve chambers 21A and 21C.

A branch flow path 27 extending in the direction of the branch flow path axis M communicates with the valve chamber 21 , and a valve seat is formed at an opening from the branch flow path 27 to the valve chamber 21 . Further, a driving portion 25 is attached to the valve main body 13 so as to face the branch flow path 27 across the valve chamber 21 in the direction of the branch flow path axis M. By reciprocating the valve body 23 in the direction of to bring the valve body 23 into contact with and away from the valve seat, the valve mechanism 17 is opened and closed to switch between flow and blockage between the main flow path 15 and the branch flow path 27. It is designed to be

In the illustrated embodiment, the valve body 23 includes a diaphragm portion 29 extending radially outwardly from the outer periphery of the upper end of the valve body 23 and having a generally circular outer periphery. The drive unit 25 includes a drive unit housing 31 in which a cylinder portion as an accommodation space is formed, a piston 33 slidably accommodated in the cylinder portion, and a piston 33 extending from the piston 33 toward the valve chamber 21 . It is composed of a stem 35 extending along the length and connected to the valve body 23, a diaphragm presser 37, and an urging member 39 for urging the piston.

The valve body 13 is formed with an opening extending to each valve chamber 21 at a position facing the branch flow path 27 in the direction of the branch flow path axis M, and a diaphragm portion 29 is arranged so as to cover the opening. be done. A diaphragm retainer 37 is attached to the bottom of the drive unit housing 31 so as to cover the opening of the cylinder unit. An outer peripheral edge of the diaphragm portion 29 is sandwiched between a diaphragm retainer 37 and the valve body 13 by a driving portion housing 31 fixed to the valve body 13 with bolts or the like. In this manner, the diaphragm portion 29 partitions the valve chamber 21 and the driving portion 25 , and the valve body 23 is arranged in the valve chamber 21 while being supported by the valve main body 13 via the diaphragm portion 29 . . A stem 35 extending from the piston 33 through a diaphragm retainer 37 is connected to the valve body 23 supported by the diaphragm portion 29 .

The space in the cylinder portion is divided into two spaces by the piston 33, one of which is provided with a biasing member 39, and the other space is supplied with and discharged with the driving fluid, thereby branching the piston 33. By reciprocating in the direction of the road axis M, the valve body 23 is brought into contact with and separated from the valve seat via the stem 35 . Specifically, in the valve mechanism portion 17A, a biasing member 39A is arranged in a space below the piston 33A in the cylinder portion in FIG. It is Therefore, by supplying the driving fluid to the space above the piston 33A in the cylinder portion, the piston 33A is moved in the direction of the branch flow path axis M against the biasing force of the biasing member 39A so as to approach the valve chamber 21A. The valve body 23 can be moved in the direction of the branch flow path axis M from a state away from the valve seat to a direction approaching the valve seat via the stem 35A, and brought into contact with the valve seat. Further, by discharging the driving fluid from the space above the piston 33A in the cylinder portion, the piston 33A is moved in the direction of the branch flow path axis M in the direction away from the valve chamber 21A by the biasing force of the biasing member 39A. , the valve body 23 can be moved away from the valve seat in the direction of the branch flow path axis M via the stem 35A to move away from the valve seat.

On the other hand, in the valve mechanism portion 17B and the valve mechanism portion 17C, the space above the pistons 33B and 33C in the cylinder portion is urged so as to apply an urging force in a direction to bring the pistons 33B and 33C closer to the valve chambers 21B and 21C. Force members 39B and 39C are arranged. Therefore, by supplying the driving fluid to the space below the pistons 33B and 33C in the cylinder portion, the valve chambers 21B and 21C are moved in the direction of the branch flow path axis M against the biasing force of the biasing members 39B and 39C. By moving the pistons 33B and 33C away from the valve seat, the valve body 23 can be moved away from the valve seat in the direction of the branch flow path axis M via the stems 35B and 35C. . Further, by discharging the driving fluid from the space below the pistons 33B and 33C in the cylinder portion, the valve chambers 21B and 21C are approached in the direction of the branch flow path axis M by the biasing forces of the biasing members 39B and 39C. By moving the pistons 33B and 33C in the direction of the branch flow channel axis M, the valve body 23 can be moved via the stem 35A in the direction of approaching the valve seat and brought into contact with the valve seat.

By configuring the valve mechanism portion 17A and the valve mechanism portions 17B and 17C so that their behaviors are different in this way, even if the driving fluid is not supplied to the valve mechanism portions 17A, 17B and 17C, The valve mechanism portion 17A is opened to allow the waste liquid to be discharged through the waste liquid switching valve 11. FIG.

As shown in FIG. 1, the valve body 23 includes a cylindrical central portion 23a and a front tapered portion that tapers from the central portion 23a toward the tip portion (the end portion on the side closer to the branch flow path 27). 23b and a rear tapered portion 23c that tapers from the central portion 23a toward the driving portion 25, and has an approximately top shape. The outer peripheral surface of the front tapered portion 23b includes a front inclined surface located on the tip side, and a front inclined surface located farther from the branch flow path 27 than the front inclined surface and forward of the branch flow path axis M. and a rear sloping surface extending at a greater angle than the side sloping surface. 2, between the valve chamber 21 and the branch flow passage 27, there is a smooth cylindrical inner peripheral surface that narrows from the valve chamber 21 toward the branch flow passage 27. An approximately funnel-shaped narrowed portion 41 is provided. The inner peripheral surface of the narrowed portion 41 is preferably a smooth curved surface curved in a convex shape, but may be a planar inclined surface. In this specification, the term "smooth" means that no projections, corners, or the like are provided on the inner peripheral surface. In the valve mechanism portion 17, the tapered outer peripheral surface of the front tapered portion 23b of the valve body 23 contacts and separates from the smooth inner peripheral surface of the throttle portion 41 having such a configuration, so that the valve chamber 21 and the branch flow path 27 are separated. Opening and closing between is performed. That is, the inner peripheral surface of the throttle portion 41 functions as a valve seat.

When the branch flow path 27 directly opens into the valve chamber 21 as in the conventional switching valve, a substantially right-angled corner is formed at the connecting portion between the inner peripheral surface of the branch flow path 27 and the wall surface of the valve chamber 21 . , this corner functions as a valve seat, and the outer peripheral surface of the front tapered portion 23b of the valve body 23 comes into contact with and separates from the corner. Then, when the front taper portion 23b of the valve body 23 is separated from the corner portion and the valve is opened, the flow passage area between the front taper portion 23b of the valve body 23 and the corner portion is rapidly narrowed. Since it expands rapidly after being closed, the flow velocity of the fluid flowing from the valve chamber 21 to the branch flow path 27 changes rapidly. As a result, the pressure loss of the fluid increases, and the flow rate from the valve chamber 21 to the branch flow path 27 tends to decrease. On the other hand, in the waste liquid switching valve 11, when the valve mechanism portion 17 is in the open state and the outer peripheral surface of the front taper portion 23b of the valve body 23 is separated from the inner peripheral surface of the throttle portion 41, the valve Since the flow passage area between the outer peripheral surface of the front tapered portion 23b of the body 23 and the inner peripheral surface of the narrowed portion 41 changes relatively slowly, the change in the flow velocity of the fluid also becomes relatively moderate. As a result, the pressure loss of the fluid is also reduced, making it easier for the fluid to flow from the valve chamber 21 to the branch flow path 27, making it possible to suppress the decrease in flow rate from the valve chamber 21 to the branch flow path 27 due to pressure loss. Become.

In addition, in the waste liquid switching valve 11, the inner peripheral surface of the throttle portion 41 is smooth, and no protrusions or the like are provided on the inner peripheral surface, so that the outer peripheral surface of the front tapered portion 23b of the valve body 23 is directly connected to the inner peripheral surface. It abuts on the inner peripheral surface of the diaphragm portion 41 . Therefore, when the fluid flows between the outer peripheral surface of the front taper portion 23b of the valve body 23 and the inner peripheral surface of the throttle portion 41, the change in flow velocity can be reduced, and the pressure loss is reduced. It becomes easier to suppress the decrease in the flow rate to the flow path 27 . In addition, when the valve seat portion has a projection, slurry or the like remains on the valve seat portion and mixes with the cleaning agent or the like to be poured next, making it impossible to reuse the cleaning agent. In the waste liquid switching valve 11, since no protrusion is provided on the inner peripheral surface of the throttle portion 41, slurry or the like can be prevented from remaining. Furthermore, in the waste liquid switching valve 11 configured as described above, when the valve mechanism portion 17 is in the closed state, the outer peripheral surface of the front tapered portion 23b of the valve body 23 and the valve seat (that is, the inner peripheral surface of the throttle portion 41) ) is made in the throttle portion 41 . Therefore, compared to the case where the corner formed at the connection portion between the wall surface of the valve chamber 21 and the inner peripheral surface of the branch flow path 27 serves as the valve seat, it protrudes along the extension of the main flow path 15 within the valve chamber 21 . It is possible to reduce the volume of the portion of the valve body 23 that is in contact. As a result, when the fluid flowing through the main flow passage 15 passes through the closed valve mechanism portion (eg, the valve mechanism portion 17B or the valve mechanism portion 17C) to the downstream side, the valve body 23 prevents the fluid from flowing. , and the fluid can easily flow downstream in the main flow path 15 . The fact that the valve body 23 includes the rear tapered portion 23 c also contributes to the effect of reducing the volume of the portion of the valve body 23 protruding along the extension of the main flow path 15 in the valve chamber 21 . From a similar point of view, since the central portion 23a of the valve body 23 has the largest diameter in the cross section in the direction perpendicular to the branch flow path axis M, the branch flow path axis M can be adjusted to the extent that the required strength can be maintained. It is preferable to reduce the thickness in the direction of . The valve body 23 may be composed only of the front tapered portion 23b and the rear tapered portion 23c without providing the central portion 23a.

When the outer peripheral surface of the front tapered portion 23b includes a front inclined surface and a rear inclined surface, the rear inclined surface is formed as shown in the valve mechanism portion 17B and the valve mechanism portion 17C in FIG. It is preferable that the valve body 23 is configured so that the . By adopting such a configuration, the fluid passing between the outer peripheral surface of the front tapered portion 23b of the valve body 23 and the inner peripheral surface of the throttle portion 41 is less likely to generate turbulence, and the retention of the fluid is prevented. can be suppressed, and adhesion of air bubbles to the valve body 23 can be suppressed.

Further, if the inner peripheral surface of the throttle portion 41 is configured by a smooth curved surface that curves in a convex shape, the outer peripheral surface of the front tapered portion 23b of the valve body 23 and the inner peripheral surface of the throttle portion 41 are in line contact. As a result, the contact area becomes smaller, so that the sealing pressure increases and the sealing performance can be improved.

Next, the details of the structure of the waste liquid switching valve 11 will be further described with reference to FIGS. 2 to 4. FIG.

As shown in FIG. 2 , the valve body 13 of the waste liquid switching valve 11 is provided with a connection path 19 for communicating an external flow path (not shown) and the main flow path 15 . The connection path 19 includes a straight tube portion 19 a connected to the external flow path, and an enlarged diameter portion 19 b provided between the straight tube portion 19 a and the main flow path 15 .

2 and 3, the valve chamber 21 has a cross section perpendicular to the branch channel axis M so that the valve body 23 can reciprocate in the direction of the branch channel axis M. The diameter is larger than the diameters of the connection path 19 and the branch flow path 27 . For this reason, the valve chamber 21 is thicker than the connection passage 19 and the main passage 15 in the direction of the width axis N perpendicular to the main passage axis L and the branch passage axis M, and a part of the valve chamber 21 extends from the connection passage 19 and the main passage. It has a shape expanded in the direction of the width axis N with respect to the path 15 in a convex shape.

When the waste liquid switching valve 11 is used in a single-wafer cleaning apparatus equipped with multi-stage cleaning tanks, the vertical width of the area occupied by the waste liquid switching valve 11 must be reduced, and the branch channel axis M becomes substantially horizontal. The waste liquid switching valve 11 is arranged as follows. Specifically, for example, the waste liquid switching valve 11 is arranged such that the drive unit 25 side of the waste liquid switching valve 11 is arranged at a position slightly higher than the branch flow path 27 side. When the waste liquid switching valve 11 is used in such an arrangement, air bubbles contained in the fluid flowing in from the external channel project in the direction of the width axis N with respect to the connection channel 19 and the main channel 15 in the valve chamber 21. It is likely to be captured and retained in the upper region of the portion (hereinafter simply referred to as “expansion portion 43”) that is expanded in a shape. The air bubbles remaining in the expanded portion 43 hinder the fluid flowing through the main flow passage 15 from smoothly passing downstream through the valve chamber 21 of the valve mechanism portion 17 in the closed state, and can be a factor in reducing the waste liquid flow rate. In particular, if the air bubbles remain in the expanded portion 43C of the valve chamber 21C of the valve mechanism portion 17C provided on the side closer to the external flow path, the effect on the decrease in the flow rate becomes greater.

In order to suppress the retention of air bubbles in such an expanded portion 43, in the waste liquid switching valve 11, the expanded portion 43 of the valve chamber 21 protrudes in the direction of the width axis N with respect to the main flow path 15 and the connection path 19. ie, the difference between the maximum dimension of the main passage 15 and the connecting passage 19 and the maximum dimension of the valve chamber 21 in the direction of the width axis N is reduced. Specifically, the connection path 19 includes a straight pipe portion 19a having a circular cross section (a cross section perpendicular to the main flow channel axis L) and a straight pipe portion 19a connected to the external flow channel toward the main flow channel 15. and an enlarged diameter portion 19b that is tapered in the direction of the width axis N and expanded. In the illustrated embodiment, the enlarged diameter portion 19b of the connection passage 19 is connected to the valve chamber 21C of the valve mechanism portion 17C provided at one end of the main flow passage 15 . Further, the cross section of the main channel 15 is expanded in the direction of the width axis N, and the length in the direction of the width axis N in the cross section of the main channel 15 is larger than the length in the direction of the branch channel axis M. As one embodiment, as shown in FIG. 4, the cross-sectional shape of the main channel 15 is a substantially rectangular shape whose length in the direction of the width axis N is greater than the length in the direction of the branch channel axis M. be able to. However, if the amount of protrusion of the expanded portion 43 of the valve chamber 21 that protrudes in the direction of the width axis N with respect to the main flow passage 15 can be reduced, the main flow passage 15 can have another cross-sectional shape. Alternatively, for example, it is possible to have an elliptical cross-section with a short axis in the direction of the branch channel axis M and a long axis in the direction of the width axis N. Moreover, it is preferable that the cross section of the main flow path 15 is larger in the direction of the width axis N than the cross section of the enlarged diameter portion 19 b of the connection path 19 .

In addition, as shown in FIG. 2, in order to reduce the resistance of the fluid flowing through the main flow path 15, the length of the main flow path 15 (the length of the maximum part in the cross section) in the direction of the branch flow path axis M And the length of the enlarged diameter portion 19b of the connection passage 19 (the length of the maximum portion in the cross section) is preferably equal to the length of the straight pipe portion 19a of the connection passage 19, and the length of the valve chamber 21 is also more preferably equal to the length of the straight tube portion 19a.

As a modification of the waste liquid switching valve 11, as shown in FIG. 45 may be provided. The chamfered portion 45 may be configured such that the inner peripheral surface of the main flow path 15 and the wall surface of the valve chamber 21 around the branch flow path axis M are connected with a curved surface by R chamfering, or the main flow path 15 is connected by C chamfering. The inner peripheral surface and the wall surface of the valve chamber 21 around the branch channel axis M may be connected by a plane. By providing such a chamfered portion 45, when the valve mechanism portion 17 is in the valve closed state, the flow becomes easier to bypass the valve body 23, and the flow in the main flow passage 15 is less likely to be obstructed.

Next, the operation of the waste liquid switching valve 11 shown in FIG. 1 will be described.

A fluid flows into the waste fluid switching valve 11 through a connection path 19 from an external channel provided in the external pipe. The fluid that has flowed into the waste liquid switching valve 11 flows through the main flow path 15 through the connection path 19 . A plurality of valve mechanisms 17 provided in the main flow path 15 are selectively opened according to the type of waste liquid flowing from the external flow path, and the valve mechanisms 17 not selected are closed. be done. In the valve mechanism portion 17 in the valve closed state, the driving portion 25 moves the valve body 23 toward the throttle portion 41 in the direction of the branch flow path axis M, and the outer peripheral surface of the front tapered portion 23b of the valve body 23 is throttled. It abuts against the inner peripheral surface of the portion 41 to prevent the fluid from flowing into the branch flow path 27 . When the valve mechanism portion 17B and the valve mechanism portion 17C are in the closed state, the fluid in the main flow path 15 flows into the valve chambers 21B and 21C, and then flows into the valve bodies 23B and 23B arranged in the valve chambers 21B and 21C. 23C and flows into the main flow path 15 on the downstream side. In addition, in the waste liquid switching valve 11, since the amount of protrusion of the expanded portion 43 of the valve chamber 21 with respect to the main flow path 15 and the connecting passage 19 is small, the air bubbles remaining in the expanded portion 43 are also moved by the flow of the fluid. Therefore, it is possible to prevent air bubbles from remaining in the expanded portion 43 and hindering the flow of fluid in the main flow path 15 .

On the other hand, in the alternatively selected valve mechanism portion 17 in the open state, the driving portion 25 moves the valve body 23 away from the throttle portion 41 in the direction of the branch flow path axis M. The outer peripheral surface of the front tapered portion 23b is separated from the inner peripheral surface of the throttle portion 41, and the fluid passes between the outer peripheral surface of the front tapered portion 23b of the valve body 23 and the inner peripheral surface of the throttle portion 41, and the fluid flows through the valve. It is discharged from the chamber 21 into the branch flow path 27 . Since the inner peripheral surface of the throttle portion 41 is tapered in a funnel shape from the valve chamber 21 toward the branch flow path 27, the inclined outer peripheral surface of the front tapered portion 23b of the valve body 23 and the inner peripheral surface of the throttle portion 41 are aligned. , the change in the flow passage area is moderate, the pressure loss is suppressed, and the fluid easily flows from the valve chamber 21 to the branch flow passage 27 . Therefore, even when the lift of the external channel is small, it becomes easy to secure a sufficient waste liquid flow rate.

Although the waste liquid switching valve according to the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the illustrated embodiments. For example, although three valve mechanisms 17 are provided in the illustrated embodiment, two or four or more valve mechanisms 17 may be provided. Further, the valve mechanism portions 17 are provided at both ends of the main flow passage 15 in the direction of the main flow passage axis L. The connection path 19 may be directly connected to the end of the main flow path 15 . Further, as the drive unit 25, a direct action type, a reverse action type, and a return action type may be appropriately selected and used according to the purpose.

11 waste liquid switching valve 13 valve main body 15 main flow path 17, 17A, 17B, 17C valve mechanism 19 connection path 19a straight pipe portion 19b enlarged diameter portion 21, 21A, 21B, 21C valve chamber 23, 23A, 23B, 23C valve element 23a Front tapered portion 27, 27A, 27B, 27C Branch channel 41 Constricted portion 43 Extended portion 45 Chamfered portion

Claims (9)

A waste liquid switching valve comprising: a valve body in which a main flow path extending linearly along a main flow path axis is formed; and a plurality of valve mechanisms provided on the main flow path,
Each valve mechanism section includes a valve chamber provided on the main flow passage, and a valve element disposed in the valve chamber and having a tapered portion at the tip thereof, and a valve main body having a valve body perpendicular to the main flow passage axis. a branch channel extending in the direction of the axis of the branch channel; and a smooth cylindrical inner peripheral surface extending between the valve chamber and the branch channel and tapering from the valve chamber toward the branch channel. A narrowed portion is formed, and the valve body is reciprocated in the direction of the branch flow path axis to bring the outer peripheral surface of the tapered portion of the valve body into contact with and separate from the inner peripheral surface of the narrowed portion. A waste liquid switching valve characterized by opening and closing a valve mechanism. 2. The waste liquid switching valve according to claim 1, wherein the inner peripheral surface of the throttle portion is a smooth curved surface that curves convexly. The valve chamber is formed to be wider than the main flow path in a width axis direction perpendicular to the main flow path axis and the branch flow path axis. 3. The waste liquid switching valve according to claim 1, wherein the length is greater than the length in the direction of the branch channel axis. 4. The waste liquid switching valve according to claim 3, wherein the cross section of the main channel has a rectangular shape that is longer in the direction of the width axis than in the direction of the axis of the branch channel. The main flow path is connected to an external flow path via a connection path, and the cross section of the main flow path is larger than the cross section of the connection path in the direction of the width axis. Waste liquid switching valve described. 6. The waste liquid switching valve according to claim 5, wherein said connection path includes an enlarged diameter portion tapered and enlarged in the direction of said width axis from said external flow path toward said main flow path. The waste liquid switching valve according to any one of claims 1 to 6, wherein a connecting portion between the main flow path and the valve chamber is chamfered. The outer peripheral surface of the taper portion of the valve body is positioned on the side farther from the branch flow path than the front side inclined surface located on the tip side and the front side inclined surface and is relative to the branch flow path axis. and a rear-side inclined surface extending at an angle larger than that of the front-side inclined surface, wherein the rear-side inclined surface contacts and separates from the inner peripheral surface of the throttle portion. The waste liquid switching valve according to item 1. The main flow path extends between a first end and a second end connected to the connection path, and the plurality of valve chambers are arranged at least at the first end and the second end. 9. The waste liquid switching valve according to any one of claims 1 to 8, which is provided at two ends.

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