JP2019124301A - Check valve - Google Patents

Abstract

To surely close a check valve to prevent water from flowing to an air driving portion when air supply to an air passage is cut off.SOLUTION: A check valve is disposed in a mechanism 1 including a supply portion 300 for supplying a mixture of air and water, a mixing portion 32 for mixing air and water, a communication passage 31 for communicating the mixing portion 32 to the supply portion 300, an air passage 41 for communicating the mixing portion 32 and an air source 40, a water passage 37 for communicating the mixing portion 32 and a water source 38, and an air supply portion 46 for communicating a branch portion 42 disposed in the air passage 41 and an air driving portion 47, and stops the water flowing from the mixing portion 32 to the air driving portion 47 between the mixing portion 32 and the branch portion 42. The check valve 5 includes a cylinder 50 vertically disposed while communicated to the mixing portion 32 at its lower end and communicated to the air source 40 at its upper end, and a floating body 51 floating on a water level of the water entering into the cylinder 50 from the lower end and vertically moving, blocks the air passage 41 when the floating body 51 is positioned at the upper end in the cylinder 50, and allows the air supply to the mixing portion 32 when the floating body 51 is separated from the upper end in the cylinder 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a check valve for preventing backflow of water.

  A processing apparatus for processing a semiconductor wafer or the like may mix water and air necessary for processing in the apparatus. For example, a grinding apparatus for grinding a wafer ejects, from the holding surface, a mixed fluid in which water and air are mixed, when the wafer is released from a chuck table that holds the wafer by suction. Besides, when cleaning the wafer, water and air are mixed and jetted from the nozzle toward the wafer.

As described above, in the processing device, air and water are mixed in the mixing unit in the device.
In addition, the air path that connects the mixing unit and the air supply source is branched in the device via a branch, and the branched air path is connected to an air driving unit such as an air cylinder or an air spindle operated by the air supply. doing.

  When a problem occurs in the air supply source and the supply of air to the air path is discontinued, the air pressure in the air path may decrease, and water supplied from the water supply source may enter the air path by water pressure. Then, the water may reach the air driving unit and damage the air driving unit. In order to prevent water from flowing to the air supply source side in order to prevent the occurrence of such damage, the spring type is provided on the mixing section side (more downstream side) than the branching section that branches the air path to the air driving section. (See, for example, Patent Document 1).

JP, 2014-003186, A

However, there is a problem that the spring-type check valve may not be properly closed when the air supply to the air passage is interrupted.
Therefore, there is a problem that when the air supply to the air path is interrupted, the check valve is reliably closed so that the water does not flow to the air driving unit.

  The present invention for solving the above problems relates to a supply unit for supplying a mixed fluid in which air and water are mixed, a mixing unit for mixing air and water, and communication between the mixing unit and the supply unit. A communication path, an air path communicating the mixing portion and an air supply source, a water path communicating the mixing portion and the water supply source, an air path driven by a branch portion disposed in the air path and the air supply A mechanism including an air supply path communicating with a drive unit, the check valve being disposed between the mixing unit and the branch unit and configured to stop water from flowing from the mixing unit to the air driving unit; And a cylinder in which the lower end is in communication with the mixing portion and the upper end is in communication with the air supply source, and the floating body floats on the water surface of water entering the cylinder from the lower end and moves vertically. When positioned at the upper end in the cylinder, the air path is shut off and the floating body is separated from the upper end in the cylinder A check valve that permits air fed to the mixing unit.

  It is preferable that the lower part in the cylinder is provided with a shielding part which suppresses the flow velocity of water entering the cylinder from the lower end.

  The check valve according to the present invention includes a supply unit that supplies a mixed fluid in which air and water are mixed, a mixing unit that mixes air and water, and a communication passage that connects the mixing unit and the supply unit. An air path communicating the mixing unit and the air supply source, a water path communicating the mixing unit and the water supply source, an air connecting the branch part disposed in the air path and the air driving unit driven by the air supply A mechanism having a supply passage, which is disposed between the mixing unit and the branching unit and is for stopping water from flowing from the mixing unit to the air driving unit, the lower end being in communication with the mixing unit and the upper end being the air The air supply from the air supply source to the air path is possible because the cylinder provided in communication with the supply source and the floating body floating on the water surface of the water entering the cylinder from the lower end and moving vertically are provided. The pressure of air in the air path is interrupted by trouble etc. When the pressure of the water to be supplied falls below, the floating body floating on the water surface of the water entering the cylinder shuts off the air passage, preventing water from flowing to the air passage on the air supply source side rather than the check valve It is possible to prevent water from entering the air drive unit. In addition, when the floating body separates from the upper end of the cylinder due to the decrease in the water pressure, the air can be supplied to the mixing unit.

  By providing a shield at the lower end of the cylinder to reduce the flow velocity of water entering the cylinder from the lower end, the water flow entering the cylinder generates a force to lower the floating body when the check valve must be closed. It is possible to prevent the occurrence of a situation where a flow passage is formed in the check valve.

It is sectional drawing which shows typically an example of the mechanism in which a non-return valve is arrange | positioned. FIG. 2A is a cross-sectional view showing the check valve of the embodiment 1 in the open state. Drawing 2 (B) is a sectional view showing the nonreturn valve of Embodiment 1 which is in a closed state. FIG. 3A is a cross-sectional view showing the check valve of the embodiment 2 in the open state. FIG. 3 (B) is a cross-sectional view showing the check valve of Embodiment 2 in the closed state. FIG. 4A is an exploded perspective view of the check valve according to the third embodiment. FIG. 4B is a perspective view showing the check valve of the third embodiment. It is a perspective view of the non-return valve of Embodiment 3 in the state where the one-touch coupling was attached. FIG. 6A is a cross-sectional view showing the check valve of the embodiment 3 in the open state. FIG. 6 (B) is a cross-sectional view showing the check valve of the embodiment 3 in the closed state.

  The mechanism 1 shown in FIG. 1 is, for example, a cutting apparatus for cutting and dividing a workpiece held by suction on a holding table 30 with a cutting blade not shown, or a workpiece to be held by suction on a holding table 30 with a grinding wheel not shown. It is a mechanism disposed in a grinding apparatus or the like for thinning a workpiece to a desired thickness, and includes a check valve 5 according to the present invention.

  For example, the holding table 30 shown in FIG. 1 has a circular outer shape and is made of a porous member or the like, and is capable of adsorbing a plate-like workpiece such as a semiconductor wafer, and is a mixed fluid in which air and water are mixed. Can be supplied onto the holding table 30, and a frame 301 supporting the supply unit 300.

  The exposed surface of the supply unit 300 is a holding surface 300a that can suction and hold a plate-like workpiece. As shown in FIG. 1, one end 31 a of the communication passage 31 made of, for example, a metal pipe or a flexible resin tube penetrates the bottom of the frame body 301 of the holding table 30 and communicates with the supply unit 300. The other end 31 b side of the communication passage 31 is in communication with the mixing unit 32 that mixes air and water.

A branch passage 33 branches from the communication passage 31, and a suction source 39 formed of a vacuum generator such as a vacuum pump or an ejector is in communication with the branch passage 33. On the branch passage 33, a vacuum valve 330 capable of switching between a state in which the branch passage 33 is in communication with the suction source 39 and a state in which the branch passage 33 is open to the atmosphere is disposed.
With the vacuum valve 330 open, the suction force generated by operating the suction source 39 is transmitted to the holding surface 300 a of the supply unit 300 via the branch passage 33 and the communication passage 31, whereby the holding table 30 is obtained. Can suction and hold the workpiece on the holding surface 300a.

  The mixing unit 32 is, for example, a chamber provided with three connection ports, and the other end 31 b of the communication passage 31 is connected to one of the connection ports as described above, and another one of the connection ports is , One end of a water path 37 through which water flows is connected. At the other end of the water path 37, a water supply source 38 constituted by a pump or the like is connected. For example, a water stop valve 371 for controlling the opening and closing of the water path 37 is disposed on the water path 37 connecting the mixing unit 32 and the water supply source 38, and the water stop valve 371 in the water path 37 A throttling valve 372 for adjusting the amount of water flowing into the mixing unit 32 is connected downstream.

  One end 41 a of an air path 41 communicating the mixing unit 32 and the air supply source 40 is connected to another connection port of the mixing unit 32. The air supply source 40 composed of a compressor, an air storage tank, and the like and connected to the other end 41 b of the air path 41 can cause compressed air to flow into the air path 41. On the upstream side (the other end 41b side) of the air path 41, a branch portion 42 such as a three-way pipe is disposed, and the branch portion 42 is other than the air supply path 46 whose one end communicates with the air drive portion 47. The end is connected. The air drive unit 47 is, for example, an air cylinder operated by supplying air, an air spindle (a spindle which supports the rotation shaft in a non-contact manner by the pressure of an air layer formed in the gap between the housing and the rotation shaft).

(1) Embodiment 1 of the check valve
A check valve 5 according to the present invention (hereinafter referred to as the check valve 5 of the first embodiment) according to the present invention is disposed downstream of the branch portion 42 of the air path 41, that is, between the branch portion 42 and the mixing portion 32. It is set up. The check valve 5 whose specific structure is shown in FIG. 2A is, for example, a cylinder 50 made of metal, plastic or the like and provided with a substantially cylindrical space inside, and a floating body accommodated in the cylinder 50. And prevents the flow of water from the mixing unit 32 to the air driving unit 47.

The upper end 50a of the cylinder 50 is in communication with the air supply source 40 via the branch portion 42 by the piping that constitutes the air path 41, and the lower end 50b of the cylinder 50 is connected to the mixing portion 32 by the piping that constitutes the air path 41. It is in communication. For example, as shown in FIG. 1, between the check valve 5 and the mixing unit 32 in the air passage 41, the air passage 41 can be switched to a state of communicating with the air supply source 40 and a state opened to the atmosphere. Air valve 44 is disposed. A throttle valve 45 for adjusting the flow rate of air flowing into the mixing unit 32 is disposed further downstream of the air valve 44.
2 (A), (B), 3 (A), (B) and 6 (A), (B), between the water supply source 38 and the lower end 50 b of the check valve 5 A part of the configuration is omitted.

  As shown in FIG. 2 (A), the floating body 51 has, for example, a spherical outer shape, and is made of metal, plastic or the like having a smaller specific gravity than water. As shown in FIG. 2A, the inside of the cylinder 50 is a cylindrical space in the present embodiment, but may be a prismatic space. When the inside of the cylinder 50 is a cylindrical space as in the present embodiment, the inner diameter of the cylinder 50> the diameter of the floating body 51. When the inside of the cylinder 50 is a prismatic space, the length of one side of the prism is equal to the diameter of the floating body 51.

  For example, on the upper end 50a side of the inside of the cylinder 50, a conical contact surface 50c is formed, the inner diameter of which decreases below the diameter of the floating body 51 toward the upper end 50a and the floating body 51 abuts at the time of valve closing. A water inlet 50 d is open at a substantially central position on the lower end 50 b side inside the cylinder 50.

For example, at the lower part in the cylinder 50, a shielding part 52 for suppressing the flow velocity of water entering the cylinder 50 from the water inlet 50d is disposed. In the cylinder 50, for example, the shielding portion 52 shown in FIG. 2A is on the inner peripheral surface on the −X direction side (the rear side in the drawing) from the inner peripheral surface on the + X direction side (the front side in the drawing) It is a plate extending transversely over the water inlet 50d toward the circumferential surface. The width in the Y-axis direction of the shielding portion 52 is smaller than the inner diameter of the cylinder 50, and a gap is formed between the shielding portion 52 and the inner circumferential surface of the cylinder 50. The shielding portion 52 is located, for example, below the floating body 51 in the cylinder 50, and when the air is supplied, the floating body 51 moves downward below the shielding portion 52 to close the water inlet 50d of the lower end 50b and air path It also plays a role of restricting the movement of the floating body 51 so that it does not close.
In addition, the shape of the plate-shaped shielding part 52 is not limited to the example shown to FIG. 2 (A), It extends in the semicircle shape so that the upper direction of the water inlet 50d of the lower end 50b may be covered in the cylinder 50. It is also good.

As shown in FIG. 2A, in a state where air is supplied from the air supply source 40 to the air path 41, the floating body 51 does not block the upper end 50a side of the inside of the cylinder 50 and the upper surface of the shield portion 52 It is in the state of getting on. The air supplied from the air supply source 40 to the air passage 41 flows into the cylinder 50 from the upper end 50a side, passes through the gap on both sides of the shielding part 52, and constitutes the air passage 41 from the water inlet 50d of the lower end 50b. , And passes through the open air valve 44 (see FIG. 1) to reach the mixing section 32.
Further, by supplying water from the water supply source 38 to the water path 37, the water passes through the open water stop valve 371 and reaches the inside of the mixing unit 32, and air and water are mixed in the mixing unit 32. Are mixed. The mixed fluid in the mixing unit 32 passes through the communication passage 31 and reaches the supply unit 300 shown in FIG. 1 so that the mixed fluid can be ejected from the holding surface 300a. In addition, since the vacuum valve 330 is closed, the mixed fluid does not flow into the suction source 39 through the branch passage 33.

  In the state shown in FIG. 2A, for example, when a trouble occurs in the air supply source 40 and the supply of air to the air path 41 is discontinued, the air pressure in the air path 41 is lowered, as shown in FIG. As shown in B), the water supplied by the water supply source 38 flows from the mixing part 32 into the air path 41 and passes through the air valve 44 (see FIG. 1) in the open state, The water enters from the water inlet 50d on the lower end 50b side.

  Here, the water collides with the lower surface of the shielding portion 52, and the flow velocity at the time of entering the inside of the cylinder 50 is lowered, and the water rises in the inside of the cylinder 50. Along with this, the floating body 51 floats on the water surface of the water entering the cylinder 50 and rises with the water surface, abuts on the contact surface 50c in the cylinder 50 and is positioned at the upper end 50a. 5 is closed. Therefore, by blocking the air passage 41, it is possible to stop the water flowing from the mixing unit 32 into the air passage 41 from flowing into the air driving unit 47.

Further, by providing the shielding portion 52 for suppressing the flow velocity of water entering the cylinder 50 from the lower end 50b in the lower portion inside the cylinder 50, the water entering the cylinder 50 generates a force to lower the floating body 51, and the flow path Can be prevented from occurring. That is, when the shielding part 52 is not provided, the water entering the cylinder 50 rushes directly to the floating body 51, causing turbulent flow in the cylinder 50 and the floating body 51 does not float on the water surface in the cylinder 50. The water surface in the cylinder 50 may rise while moving in the water irregularly or sinking in the water. In this case, the water surface may reach the upper end 50a before the floating body 51 abuts on the contact surface 50c, and a state in which the air passage 41 is not closed by the check valve 5 may occur. However, as in the present embodiment, the check valve 5 is provided with the shielding portion 52, so that the water flow entering the cylinder 50 does not rush directly against the floating body 51, so the floating body 51 has a water surface inside the cylinder 50. The check valve 5 is in a closed state reliably because it floats and rises without irregular movement.
Depending on the amount of water supplied from the water supply source 38, the check valve 5 may be configured not to include the shielding portion 52.

  For example, when air is again supplied from the air supply source 40 to the air path 41 by the operator solving the trouble of the air supply source 40, the air flows into the cylinder 50 from the upper end 50 a side, and the cylinder 50 As the air pressure inside increases and the water pressure in the cylinder 50 relatively decreases, the water surface in the cylinder 50 descends and the floating body 51 separates from the contact surface 50 c of the upper end 50 a of the cylinder 50. Thus, when the check valve 5 is in the open state, the air that has passed through the air path 41 is supplied to the mixing unit 32 as described above.

(2) Embodiment 2 of the check valve
On the downstream side of the branch portion 42 of the air passage 41, instead of the check valve 5 of the first embodiment shown in FIGS. 2 (A) and 2 (B), FIGS. 3 (A) and 3 (B) will be described below. The check valve 5A of the second embodiment shown in FIG.
The check valve 5A of the second embodiment is the same as the check valve 5 of the first embodiment except that the shield 52 and the water inlet 50d of the check valve 5 of the first embodiment are changed. There is.
On the lower end 50b side of the check valve 5A, the water inlet 50e into which the water from the water supply source 38 flows extends upward in the side wall of the cylinder 50 and then bends radially inward, and the inner peripheral surface of the cylinder 50 It is open at the bottom. The bent portion of the water inlet 50 e acts as a shielding portion 54 for suppressing the flow velocity of water entering the cylinder 50 from the lower end 50 b, and the water enters the cylinder 50 from the side.
Between the opening at the lower portion of the inner peripheral surface of the cylinder 50 of the water inlet 50e and the floating body 51 located at the lower end 50b, a gap through which the air directed to the mixing unit 32 can pass is always formed. For example, a plurality of projections (not shown) are disposed around the opening at the lower portion of the inner peripheral surface of the cylinder 50 of the water inlet 50e, and the floating body 51 is the inner periphery of the cylinder 50 of the water inlet 50e. The opening at the lower side of the surface may not be closed.

  As shown in FIG. 3A, when air is supplied from the air supply source 40 to the air path 41, the floating body 51 is positioned at the lower end 50b in the cylinder 50, and the check valve 5A is in the open state. ing. Therefore, the air flows into the cylinder 50 from the upper end 50a side, flows from the water inlet 50e on the lower end 50b side to the pipe that constitutes the air path 41, and passes through the open air valve 44 (see FIG. 1). The mixing unit 32 is reached. Further, water is supplied from the water supply source 38 into the mixing section 32 through the water path 37 in an open state, and air and water are mixed. Then, the mixed fluid passes through the communication passage 31 and is ejected from the holding surface 300 a of the supply unit 300.

  In the state shown in FIG. 3A, for example, when the air supply to the air path 41 is interrupted due to a trouble with the air supply source 40 and the air pressure in the air path 41 is lowered, as shown in FIG. Water supplied from the supply source 38 flows from the mixing unit 32 into the air path 41 and enters the cylinder 50 from the water inlet 50 e on the lower end 50 b side. The water collides with the shielding portion 54 in the water inlet 50 e to reduce the flow velocity when entering the cylinder 50. Then, the floating body 51 floats on the water surface of the water entering from inside the cylinder 50 from the side, and rises with the water surface to abut the abutment surface 50c in the cylinder 50 and be positioned at the upper end 50a. 5A is closed, the air path 41 is blocked, and water flowing from the mixing portion 32 into the air path 41 can be prevented from flowing into the air driving portion 47.

  Further, by providing the shielding portion 54 for suppressing the flow velocity of water entering the cylinder 50 from the lower end 50b in the lower portion in the cylinder 50, the water flow entering the cylinder 50 generates a force to lower the floating body 51 Can be prevented from occurring.

  For example, when the operator solves the trouble of the air supply source 40 and air is supplied again from the air supply source 40 to the air path 41, the air flows into the cylinder 50 from the upper end 50a side, and the water pressure in the cylinder 50 By lowering, the water surface in the cylinder 50 descends, and the floating body 51 separates from the contact surface 50 c of the cylinder 50. By the check valve 5A being in the open state, the air having passed through the air path 41 is supplied to the mixing unit 32.

(3) Embodiment 3 of the check valve
On the downstream side of the branch portion 42 of the air passage 41, instead of the check valve 5 of the first embodiment shown in FIGS. 2 (A) and 2 (B), FIGS. 4 (A) and 4 (B) will be described below. The non-return valve 5B of Embodiment 3 shown to these may be arrange | positioned.
Similar to the check valve 5 of the first embodiment, the check valve 5B shown in FIGS. 4A and 4B is housed in a cylinder 50 provided with a cylindrical space inside and a cylinder 50. And a floating body 51. Further, a second sleeve 56 having a short cylindrical outer shape is attached to an opening on the upper end 50a side of the cylinder 50, and a first sleeve 55 having a substantially cylindrical outer shape is attached to an opening on the lower end 50b .

  The second sleeve 56 in which the flow passage 560 smaller than the diameter of the floating body 51 is formed is provided with a flange-like hooking portion 561 extending radially outward on the upper end side thereof. For example, on the lower end side of the flow passage 560, a conical abutment surface 560c with which the floating body 51 abuts when the check valve 5B is closed is formed. As shown in FIG. 4B, the second sleeve 56 is, for example, fitted in the opening on the upper end 50a side of the cylinder 50, and the hooking portion 561 abuts on the upper end surface of the cylinder 50 and is vertically displaced. It is attached to the cylinder 50 in a manner such that there is no

  The first sleeve 55 has an outer diameter slightly smaller than the inner diameter of the cylinder 50, a fitting portion 550 fitted to the cylinder 50, and a diameter smaller than the fitting portion 550 and protrudes upward from the fitting portion 550 A shielding portion 551 for suppressing the flow velocity of water entering the cylinder 50 from the lower end 50 b and a flange-like hooking portion 552 extending radially outward on the lower end side of the fitting portion 550 are provided. A flow path 553 is formed from the lower end side of the fitting portion 550 to the shielding portion 551, and the upper end side of the flow path 553 is branched, for example, at equal intervals in the circumferential direction in the shielding portion 551 It extends outward and opens at the outer peripheral surface of the shielding portion 551.

As shown in FIG. 4B, the first sleeve 55 is inserted into the opening on the lower end 50b side of the cylinder 50, and the hooking portion 552 abuts on the lower end surface of the cylinder 50 and does not shift vertically. Thus, it is attached to the cylinder 50. The floating body 51 is placed on the upper surface of the shielding portion 551, and a gap is formed between the inner peripheral surface of the cylinder 50 and the outer peripheral surface of the shielding portion 551.
Further, as shown in FIG. 5, one-touch joints 58A and 58B which can be attached by one-touch operation are respectively attached to the upper end side and the lower end side of the check valve 5B assembled as shown in FIG. It connects to the piping which comprises the air path 41 via the couplings 58A and 58B. The check valve 5B configured in this way can be assembled or disassembled only by using, for example, a tool-free or simple tool, and maintenance of the inside of the cylinder 50 after use, etc. can be easily performed.

  As shown in FIG. 6A, in a state where air is supplied from the air supply source 40 to the air path 41, the floating body 51 is positioned at the lower end 50b in the cylinder 50, and the check valve 5B of the third embodiment It is open. Therefore, the air passes through the flow path 560 of the one-touch joint 58A and the second sleeve 56, flows into the cylinder 50 from the upper end 50a side, and passes through the flow path 553 of the first sleeve 55 and the one-touch joint 58B. Then, it flows to the piping that constitutes the air path 41 and reaches the mixing unit 32. Further, water is supplied from the water supply source 38 into the mixing unit 32 through the water path 37, and air and water are mixed. Then, the mixed fluid passes through the communication passage 31 and spouts from the holding surface 300 a (see FIG. 1) of the supply unit 300.

  In the state shown in FIG. 6A, for example, when the air supply to the air path 41 is stopped due to a trouble with the air supply source 40 and the air pressure in the air path 41 is lowered, as shown in FIG. Water supplied from the supply source 38 flows into the air path 41 from the mixing unit 32. The water passes through the inside of the shielding portion 551 of the first sleeve 55 to suppress the flow velocity, and then enters the cylinder 50 from the lower end 50 b side. Then, the floating body 51 floats on the water surface of the water coming into the cylinder 50 and rises with the water surface without directly colliding with the floating body 51, and abuts on the contact surface 560c of the second sleeve 56. Being positioned at the upper end 50 a of the cylinder 50, the check valve 5 B is closed to shut off the air passage 41, and water flowing from the mixing unit 32 into the air passage 41 can be prevented from flowing into the air driving unit 47.

  Further, by providing the shielding portion 551 for suppressing the flow velocity of water entering the cylinder 50 from the lower end 50b in the lower portion in the cylinder 50, the water flow entering the cylinder 50 generates a force to lower the floating body 51 Can be prevented from occurring.

  When the operator solves the trouble of the air supply source 40 and air is supplied again from the air supply source 40 to the air path 41, the air flows into the cylinder 50 from the upper end 50a side, and the water pressure in the cylinder 50 decreases. Then, the water surface in the cylinder 50 descends, and the floating body 51 separates from the contact surface 560c. The air passing through the air passage 41 is supplied to the mixing unit 32 as the check valve 5B is opened.

1: Mechanism 30: Holding table 300: Supply unit 300a: Holding surface 301: Frame 31: Communication passage 32: Mixing unit 33: Branching passage 330: Vacuum valve 39: Suction source 38: Water supply source 37: Water path 371: Water stop valve 372: throttle valve 40: air supply source 41: air path 42: branch portion 44: air valve 45: throttle valve 46: air supply path 47: air drive portion 5: check valve of the first embodiment 50: cylinder 50c : Contact surface 50d: Water inlet 51: Floating body 52: Shield 5A: Check valve of Embodiment 2 50e: Water inlet 54: Shield 5B: Check valve of Embodiment 3 55: First sleeve 551: Shield Part 56: Second sleeve 58A, B: One-touch coupling

Claims (2)

A supply unit for supplying a mixed fluid in which air and water are mixed, a mixing unit for mixing air and water, a communication passage connecting the mixing unit and the supply unit, a mixing unit and an air supply source An air passage communicating with the water supply passage, a water passage communicating the mixing unit and the water supply source, and an air supply passage communicating the branching unit disposed in the air passage with the air driving unit driven by the air supply; A check valve disposed between the mixing unit and the branch unit to stop water from flowing from the mixing unit to the air driving unit,
The lower end is communicated with the mixing unit and the upper end is communicated with the air supply source, and the floating body floats on the surface of the water which has entered the cylinder from the lower end, and the floating body is the cylinder A non-return valve which shuts off the air passage when positioned at the upper end inside and allows air supply to the mixing unit when the floating body separates from the upper end in the cylinder.   The non-return valve according to claim 1, further comprising a shielding portion for suppressing the flow velocity of water entering the cylinder from the lower end in the lower portion in the cylinder.

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