JP2017087116A - Two-fluid nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-fluid nozzle of which a structure is simplified and of which downsizing is achieved.SOLUTION: A two-fluid nozzle comprises: a piston for opening/closing a liquid passage which is so provided along a center axis in a body of a nozzle as to be movable forward and backward, has a solid rod part in the front of an injection side and has a cylinder part in the rear of the injection side; a cylinder accommodation chamber which so accommodates the cylinder part of the piston as to be movable forward and backward; a spring which presses a rear end face of the cylinder part in the cylinder accommodation chamber thereby energizing in a valve closing direction; a liquid passage which comprises a valve seat, which is opened/closed by a valve part at a rod side forward end of the piston, in a passage midway, and which communicates a mixing chamber at a forward end of the passage and a liquid introduction port opened to a side face of the body with each other; an air passage for spraying which communicates an air introduction port opened to the side face of the body and the mixing chamber with each other; and a pilot air passage which communicates the air introduction port opened to the side face of the body and a pilot air introduction port at a forward end of the cylinder accommodation chamber with each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a two-fluid nozzle, and more particularly, in a two-fluid nozzle that mixes and injects gas (air) and liquid (water) and has a liquid passage (usually a water passage) provided with spraying and stopping inside the nozzle. The operation is performed by opening and closing by a pneumatically operated piston provided inside the nozzle.

  Conventionally, when a large number of two-fluid nozzles are used in parallel, the spraying and stopping of the nozzles are controlled by the liquid passages provided inside the nozzles with liquid and compressed air supplied to each nozzle from the main pipe. The opening / closing piston is operated by pilot air supplied to the nozzle. Conventionally, as a two-fluid nozzle provided with this kind of opening and closing piston, Japanese Patent Application Laid-Open No. 2007-90221 (Patent Document 1) and Utility Model Registration No. 2521116 (Patent Document 2) related to the applicant's application are disclosed. There is a nozzle disclosed in Japanese Unexamined Patent Publication No. 2000-246151 (Patent Document 3).

  The nozzle 100 of Patent Document 1 has a structure shown in FIGS. 9A and 9B, and a liquid passage 102 is provided at the center of a piston 101 that is moved back and forth by supply and discharge of pilot air moving along a central axis. An air passage 103 is provided on the outer periphery, and liquid and air are mixed in the mixing chamber 105 and sprayed from the nozzle 104. A pilot air pipe 110 is provided which branches an air supply pipe 108 for supplying air to the air passage 103 and connects to the pilot air supply / discharge passage 109 of the nozzle. Air is supplied to the pilot air supply / discharge passage 109 to advance the piston 101 to the injection side, and the liquid passage 102 is closed as shown in FIG. 9A, and the air supply to the air passage 103 is stopped. While spraying is stopped, as shown in FIG. 9B, air is exhausted from the pilot air supply / discharge passage 109 and air is supplied to the air passage 103 to retract the piston 101 to open the liquid passage 102. Spraying.

  Further, as shown in FIGS. 10A and 10B, the nozzle of Patent Document 2 is provided with an air passage 208 along the central axis of a piston 201 for opening and closing liquid inflow provided in the nozzle 200, and from the air passage 208. A part of the inflowing air acts on the pressure receiving surface (anti-injection side) 201a of the piston 201 to push down the piston 201 against the spring 212 on the back side of the piston 201 to open the liquid valve seat 203, and from the liquid inlet The inflowing liquid is guided to the mixing chamber 205, mixed with the air from the air passage 208 in the mixing chamber 205, and sprayed from the nozzle 204 as shown in FIG. On the other hand, as shown in FIG. 10B, air is supplied to the pilot inflow port 211 through the pilot air supply pipe 210 to the rear surface of the piston 201, and the piston 201 is pressed together with the spring 212 to the injection side to thereby liquid valve seat 203. Is closed, and only the air passing through the air passage 208 provided in the piston 201 is injected from the injection port 204.

  Furthermore, the nozzle of Patent Document 3 relating to the applicant's co-application has the same configuration as the nozzle of Patent Document 2, and is provided with an air passage using a piston rod portion as a cylinder, mixed with liquid, and sprayed. Air is supplied to the working surface of the large-diameter portion of the piston and the piston is pushed down to open the liquid passage, while pilot air is supplied to the back surface of the piston to advance the piston and close the liquid passage.

JP 2007-90221 A Utility Model Registration No. 2521116 JP 2000-246151 A

  In the nozzle of Patent Document 1 having the structure shown in FIG. 9, the rod portion and the large-diameter portion that protrude to the injection side of the piston 101 are sleeves, and the hollow portion that penetrates is the liquid passage 102, so the liquid flow rate should be increased. Then, the diameter of the rod portion of the piston 101 is increased, the area of the pressure receiving surface of the piston on which the pilot air acts is reduced, and the pressure of the pilot air needs to be increased. Moreover, in order to stop the injection instantaneously and without liquid leakage, it is necessary to increase the area of the pressure receiving surface of the piston, and there is a problem that the nozzle itself becomes large.

  Similarly to the nozzle of Patent Document 1, the nozzle of Patent Document 2 shown in FIG. 10 is also provided with an air passage 208 using a rod portion 201r of the piston 201 that opens and closes the liquid passage as a sleeve. In order to increase the amount of air mixed with the liquid, it is necessary to increase the thickness of the rod portion 201r. In this case, the pressure receiving surface 201a of the large-diameter cylinder portion 201b of the piston 201 is reduced. Therefore, it is necessary to enlarge the large-diameter cylinder part 201b of the piston 201 in order to stop the spraying instantaneously and stop the liquid leakage reliably, and the nozzle 200 is increased in size. The nozzle of Patent Document 3 having the same structure as that of Patent Document 2 has the same problem as described above.

  Thus, since the nozzles of Patent Documents 1 and 2 that have been provided in the past are provided with a liquid passage or an air passage using the rod portion of the piston for opening and closing the liquid passage as a sleeve, the liquid or gas flowing through the passage is provided. When the flow rate is increased, there is a problem that the piston is enlarged, the spring for urging the piston is enlarged, and the nozzle is enlarged. Furthermore, it is necessary to add compressed air to the spring force of the spring, and the piping becomes complicated. In addition, when the rod portion is a sleeve and the thin hollow is a liquid passage, there is a problem that foreign matters mixed in the liquid are easily clogged in the liquid passage.

  Further, the nozzle is provided with an orifice (minimum cross-sectional portion) in the fluid passage in order to increase the injection pressure. In the nozzles of FIGS. 9 and 10 as well, the orifice 300 is provided at the mixing portion of air and liquid. The passage cross-sectional area increases on the outflow side. Thus, if there is a portion where the cross-sectional area is partially increased in the passage, turbulent flow is generated in the fluid in the portion. Due to this turbulent flow, foreign substances such as silica, calcium, and magnesium contained in a liquid such as water adhere to the inner peripheral surface of the liquid passage, which accumulates and causes clogging. The same applies to gases such as air, and foreign substances contained in the gas adhere to the inner peripheral surface of the passage and cause clogging of the gas passage. In particular, if the passage is bent at a portion where the cross-sectional area of the passage is large, or if there is a corner on the inner peripheral surface of the passage, turbulent flow is likely to occur, and foreign matter accumulates along the corner and clogs the passage. Some problems are likely to occur.

According to the present invention, in the conventional two-fluid nozzle that opens and closes the liquid flow path by operating the piston with pilot air, the piston rod portion is hollow, and the piston is miniaturized without providing a liquid passage or an air passage. The main issue.
Another problem is to prevent foreign matter from adhering to the inner surface of the passage and reduce or prevent clogging at the orifice and passage bends and corners provided at the site where liquid and air are mixed. Yes.

In order to solve the above problems, the present invention provides:
A piston for opening and closing a liquid passage, which is disposed in the body of the nozzle so as to be able to move back and forth along the central axis, has a solid rod part at the front part on the injection side and has a cylinder part at the rear part, and a cylinder of the piston A cylinder housing chamber for housing the part so as to freely move forward and backward,
A spring that presses against a rear end surface of the cylinder portion in the cylinder housing chamber and biases it in a valve closing direction;
A fluid passage that is provided in the middle of the passage with a valve seat that is opened and closed by a valve portion at the front end of the rod portion of the piston, and that communicates a mixing chamber at the front end of the passage and a liquid inlet opening on a side surface of the body; An air inlet opening on the side surface of the spraying air passage for communicating with the mixing chamber;
A pilot air passage that communicates an air inlet opening on the side of the body and a pilot air inlet at the front end of the cylinder housing chamber;
The piston is retracted by the air supplied to the pressure receiving surface of the front surface of the cylinder portion of the piston to open the valve seat of the liquid passage and mix and spray two fluids, while acting on the rear surface of the piston portion of the piston. A two-fluid nozzle is provided in which a piston is advanced by the spring to close the valve seat and stop spraying.

  The nozzle of the present invention having the structure described above is a nozzle having a piston that opens and closes a liquid passage, and the rod portion of the piston having a valve portion at the tip is a relatively small pin-shaped solid body. Since the rod is not a liquid passage or an air passage as in -3, the rod portion can be made thin. As a result, the area of the pressure receiving surface of the cylinder portion of the piston that projects the rod portion toward the center can be increased, and the downsizing of the nozzle can be promoted while speeding up the operation of the piston without increasing the size of the piston.

The liquid passage communicating with the liquid introduction port opens into a rod housing chamber in which the rod portion of the piston moves forward and backward, and enters the mixing chamber via a valve seat of the liquid passage located at the front end of the rod housing chamber. Communication,
The spraying air passage communicating with the air introduction port communicates with the mixing chamber via an air passage provided on the injection side from the valve seat,
Further, a vent hole is provided in the wall of the body surrounding the cylinder housing chamber that houses the spring to release it to the atmosphere.

The air inlet is provided separately at a position close to the side surface of the body with a spray air inlet that communicates with the spray air passage and a pilot air inlet that communicates with the pilot air passage;
Alternatively, the number of the air inlets is one, and the atomizing air passage and the pilot air passage are communicated with the air inlet.

  In either case, the liquid is always supplied to the liquid inlet, and when the spray air inlet and the pilot air inlet are separated, the air is always supplied to the spray air passage and the pilot air passage is sprayed. Sometimes pilot air is introduced and the supply of pilot air is stopped when spraying is stopped.

The outer surface of the body where the air inlet and the liquid inlet are provided is rectangular, and the liquid inlet and the air inlet are provided on two opposite sides of the four sides,
When the spraying air inlet and the pilot air inlet are provided separately, it is preferable to provide them on adjacent sides.

As described above, when the spraying air introduction port and the pilot air introduction port are separately provided, the passage is provided in the side close to the body of the nozzle, so that the passage provided in the nozzle can be easily formed.
In particular, when one air inlet is provided in the body of the nozzle and a part of the air introduced at the time of spraying is used as pilot air to actuate the piston and open the liquid passage, Even if pilot air is not supplied to the back surface of the nozzle, the piston moves by the spring on the back side to close the liquid passage, and it is only necessary to connect one air supply pipe to one air inlet of the nozzle. Thus, the piping is simplified and the passage provided in the nozzle is also simplified, so that the nozzle can be further downsized.

  Further, the valve portion provided at the tip of the rod portion having a small diameter of the piston has a trapezoidal shape, and an O-ring is provided in an annular mounting recess provided on the conical circumferential surface as a seal material between the valve seat. It is preferable to fit.

Further, an X ring made of an annular body having an X-shaped cross section is interposed between the outer peripheral surface of the intermediate portion in the longitudinal direction of the rod portion of the piston and the inner surface of the rod housing chamber as a sealing material for preventing liquid leakage. At the same time, it is preferable to place a Teflon (registered trademark) backup ring on the front side of the X ring.
The reason for using the X-ring is that when the rod part diameter is reduced, the ring diameter also becomes smaller, and problems such as twisting of the ring and burrs during molding cause problems in durability and sealability. Instead, a 0 ring may be used.
The backup ring is used to prevent the X ring from sticking out.

  Further, the Y air packing is interposed between the outer peripheral surface of the large-diameter cylinder portion of the piston and the inner peripheral surface of the cylinder chamber, so that pilot air acting on the pressure receiving surface on the entire surface of the large-diameter cylinder portion It is preferable to prevent leakage to the back side and to ensure that air pressure acts on the pressure receiving surface of the cylinder part.

At the center of the inflow side of the mixing chamber in the body of the nozzle, a peripheral wall surrounding the spraying air passage projects, and the front end of the liquid passage opens to the inflow side outer periphery of the mixing chamber,
The front end side outer peripheral surface of the peripheral wall surrounding the spraying air passage and the inner peripheral surface of the mixing chamber surrounding the front end side outer peripheral surface are inclined toward the front end in the direction of diameter reduction to reduce the diameter to the front end side of the liquid passage. It is preferable that an annular inclined liquid passage is provided, and the liquid flowing from the inclined liquid passage into the mixing chamber is sucked with a gas injected from an air injection port at the front end of the spraying air passage.

  As described above, instead of providing an orifice with a reduced channel cross-sectional area in the liquid passage, an annular inclined liquid passage that is reduced in diameter toward the mixing chamber is provided. In the inclined liquid passage, the flow passage cross-sectional area in the length direction and perpendicular to the axis is gradually reduced, so that the hydraulic pressure can be gradually increased. Thus, since the transverse orifice is not provided in the flow path, the flow path sandwiching the orifice does not expand, and there is no portion where turbulence occurs. As a result, it is possible to reduce or prevent the foreign matter in the liquid from adhering to the inner peripheral surface surrounding the liquid supply path and accumulating it.

Further, the peripheral edge of the air injection port at the tip of the spraying air passage has an acute angle, and the front end side inner peripheral surface of the peripheral wall surrounding the spraying air passage is inclined to communicate with the air injection port at the front end of the air passage. The passage is preferably an inclined air passage.
And the said inclination air passage which continues to the periphery of the said air injection opening is provided with the 1st inclination part and the 2nd inclination part which continues to this 1st inclination part,
Preferably, the first inclined portion is inclined by 0 to 5 degrees with respect to the nozzle axis, and the second inclined portion is inclined by 10 to 30 degrees with respect to the nozzle axis.

The present invention further comprises a mixing chamber for mixing the liquid introduced through the liquid passage into the nozzle body and the air introduced through the atomizing air passage,
At the center of the inflow side of the mixing chamber in the body of the nozzle, a peripheral wall surrounding the spraying air passage projects, and the front end of the liquid passage opens to the inflow side outer periphery of the mixing chamber,
A liquid passage on the inflow side of the mixing chamber in which a front end side outer peripheral surface of the peripheral wall surrounding the spraying air passage and an inner peripheral surface of the mixing chamber surrounding the front end side outer peripheral surface are inclined toward the front end in a diameter reducing direction. A two-fluid nozzle having an annular inclined liquid passage with a reduced diameter is provided.

The two-fluid nozzle of the present invention is a nozzle having a piston that opens and closes a liquid passage, and a rod portion of a piston having a valve portion at the tip is a relatively small pin-shaped solid body, as in Patent Documents 1 to 3 described above. Since the rod is not used as a sleeve for a liquid passage or an air passage, the rod portion can be made thin. As a result, the area of the pressure receiving surface of the cylinder portion of the piston that projects the rod portion toward the center can be increased, and the downsizing of the nozzle can be promoted while speeding up the operation of the piston without increasing the size of the piston. Therefore, the size of the two-fluid nozzle of the present invention can be reduced to less than half that of the conventional nozzle shown in FIG.
In addition, since the piston is downsized, the spring that urges the piston from the back side can be downsized, and it is not necessary to operate the piston by applying compressed air pressure to the spring pressure of the piston, simplifying the air piping path can do.
Further, since the rod portion of the piston is not used as a flow path, it has various advantages such that the amount of spray liquid can be increased without causing clogging in the flow path.

  Further, an annular inclined liquid passage having a reduced diameter is provided on the inflow side of the mixing chamber for mixing the liquid introduced from the liquid passage and the air introduced from the spraying air passage, and the inclined liquid passage is perpendicular to the length in the length direction. By gradually increasing the hydraulic pressure by gradually reducing the cross-sectional area of the channel in the direction, a structure in which no transverse orifice is provided in the flow channel can prevent the occurrence of turbulent flow in the flow channel portion sandwiching the orifice. As a result, it is possible to reduce or prevent the foreign matter in the liquid from adhering to the inner peripheral surface surrounding the liquid supply path and accumulating it.

The two-fluid nozzle of 1st embodiment of this invention is shown, (A) is sectional drawing of an axial direction, (B) is sectional drawing of an orthogonal direction with (A), (C) is a principal part enlarged view of (A). It is. It is a rear view which shows the positional relationship of the air inlet and the liquid inlet of the said 2 fluid nozzle. It is drawing which shows the piping system of the two fluid nozzle of said 1st embodiment. It is sectional drawing at the time of spraying of the said 2 fluid nozzle. It is sectional drawing which shows the 1st modification of the mixing part of the liquid of the said 2 fluid nozzle, and the air for spraying. It is sectional drawing which shows the 2nd modification of the mixing part of the liquid of the said 2 fluid nozzle, and the air for spraying. The two-fluid nozzle of 2nd embodiment is shown, (A) is sectional drawing of an axial direction, (B) is a rear view which shows the positional relationship of an air inlet and a liquid inlet. It is drawing which shows the piping system of the 2 fluid nozzle of 2nd embodiment. (A) (B) is sectional drawing which shows a prior art example. (A) (B) is sectional drawing which shows another prior art example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 4 show a two-fluid nozzle according to the first embodiment.
The two-fluid nozzle is smaller than the two-fluid nozzle of the applicant's previous application shown in FIG. The external shape is rectangular.

  The two-fluid nozzle 1 (hereinafter abbreviated as “nozzle 1”) has a body 2 with an injection side F on the front side and an injection port 4, while the rear end on the non-injection side has a closed wall and a vent hole 2 h in the center. Yes. The outer shape of the rear side of the body 2 has a rectangular shape, and the cylinder housing chamber 5 and the rod housing chamber 6 that house a piston 12 having a solid rod portion 10 and a cylinder portion 11 therein so as to be able to move forward and backward are arranged along a central axis L. In line with. As shown in FIG. 2, among the four sides of the rectangular body 2, the spraying air inlet 7 and the liquid inlet 8 are provided on the opposite side, and the pilot air inlet 9 is provided on the other side. .

  The spraying air introduction port 7 communicates with a mixing chamber 21 provided along the central axis L via a spraying air passage 20. Specifically, the air passage 20 has the atomizing air introduction port 7 connected to the central air passage 20b along the central axis L via the inclined air passage 20a, and the center of the inflow side of the mixing chamber 21 at the front end of the central air passage 20b. A small-diameter air passage 20d surrounded by a peripheral wall 20c protruding to the center is provided, and the tip of the small-diameter air passage 20d is opened at the center of the mixing chamber 21 as an air injection port 20f. The spray air passage 20 that continues to the mixing chamber 21 is in a position that is not opened and closed by the piston 12, and when the introduction of air into the spray air introduction port 7 is stopped, no air flows into the air passage 20, When air is introduced into the air introduction port 7, the air flows into the air passage 20 and is ejected from the ejection port 4.

  The liquid inlet 8 opens on the side surface of the rod accommodating chamber 6 and communicates with a liquid passage 23 reaching the mixing chamber 21 via a valve seat 22 provided at the front end in the rod accommodating chamber 6. When the rod portion 10 of the piston 12 moves forward in the rod housing chamber 6, the valve seat 22 is closed to block the flow of liquid, and when the rod portion 10 moves backward, the valve seat 22 is opened to inject liquid. As shown in FIG. 1C, the liquid passage 23 is provided with a liquid jet 23i that opens on the inflow side of the mixing chamber 21, and a peripheral wall 20c that surrounds the small-diameter air passage 20d projects from the center of the liquid jet 23i. doing. The inner surface from the inflow side of the mixing chamber 21 to the mixed liquid outlet 21i at the front end is an inclined surface 21b that reduces the diameter, and an inclined liquid passage 23k is provided.

  As shown in FIG. 1 (B), the pilot air inlet 9 communicates with the front end opening of the cylinder housing chamber 5 through a pilot air passage 25 provided in the body 2. When pilot air is introduced from the pilot air inlet 9 into the cylinder housing chamber 5 through the pilot air passage 25, air pressure acts on the pressure receiving surface 11s of the large diameter portion 11a of the cylinder portion 11, and the spring 15 on the back side. The piston 12 is retracted by overcoming the spring force, and the valve seat 22 is opened to allow the liquid to pass therethrough.

  As described above, the piston 12 is used for opening and closing the liquid passage 23, and the valve portion 13 having a truncated cone shape is provided at the front end of the pin-shaped rod portion 10 having a relatively small diameter. The valve seat 22 provided on the way is opened and closed. The cylinder portion 11 of the piston 12 has a step shape having a large diameter portion 11a at the front portion and a medium diameter portion 11b at the rear portion. A small-diameter rod portion 10 is projected forward from the center of the pressure-receiving surface 11s on the front surface of the large-diameter portion 11a. Since the rod portion 10 has a small diameter, the area of the pressure receiving surface 11s of the cylinder portion 11 is increased.

The outer peripheral surface of the large-diameter portion 11a of the cylinder portion 11 is slidably in contact with the inner surface of the cylinder housing chamber 5, and a seal fitting recess 11e is provided on the outer peripheral surface, and a rubber Y-packing 16 is fitted, Air acting on the surface 11s is prevented from leaking to the back side (rear side).
The spring 15 is mounted between the rear surface of the large-diameter portion 11a and the rear end closing wall 2E, and the piston 12 is urged forward on the injection side in the valve closing direction. That is, the piston 12 is always urged by the spring 15 in the forward valve closing direction, and when the air pressure of the pilot air acts on the pressure receiving surface 11 s of the cylinder portion 11, the piston 12 moves backward against the spring force of the spring 15, The passage is to be opened.

  The valve portion 13 provided at the tip of the rod portion 10 having a small diameter of the piston 12 has a trapezoidal shape, and a rubber 0-ring 26 is attached as a sealing material when the valve portion 13 and the valve seat 22 are closed. . Specifically, a conical annular mounting recess is provided on the conical circumferential surface of the valve portion 13, and a rubber 0-ring 26 is fitted and fixed to the mounting recess.

  Further, an X ring 28 made of an annular body having an X-shaped cross section is used as a sealing material for preventing liquid leakage between the outer peripheral surface of the intermediate portion in the longitudinal direction of the rod portion 10 of the piston 12 and the inner surface of the rod housing chamber 6. Intervene. Further, a backup ring 29 made of Teflon (registered trademark) is interposed on the front side of the X ring 28. A 0 ring may be used in place of the X ring 28.

  The nozzle 1 communicates the liquid mixture outlet 21i at the front end of the mixing chamber 21 with a large-diameter chamber 32 through a small-diameter passage 31, and communicates the large-diameter chamber 32 with an ejection chamber 33 having a dome-shaped tip on the ejection side. The two fluids, which are a mixture of air and water, are sprayed from the nozzle 4 provided on the injection side tip wall.

  As shown in FIG. 2, the two-fluid nozzle is supplied with water having a required pressure by connecting a water pipe 36 to the liquid inlet 8. In addition, the compressed air pipe 37 is branched near the nozzle to the spraying air introduction port 7 and the pilot air introduction port 9 in the adjacent positions, and the branching pipes 37A and 37B are respectively connected to the spraying air introduction port 7 and the pilot air introduction port. 9 is connected to each.

  The air system piping path and the liquid system piping path have the structure shown in FIG. The compressed air supplied to the nozzle 1 as spraying air and pilot air is supplied from the air compressor 50 through the compressed air pipe 37, and after the air filter 51 is interposed in the compressed air pipe 37, the branched pipes 37A and 37B are branched. ing. A two-way solenoid valve 52, an on-off valve 53, and a pressure gauge are interposed in the branch pipe 37A connected to the atomizing air inlet 7, while a three-way solenoid valve 54 is provided in the branch pipe 37B connected to the pilot air inlet 9. Intervene. Further, an open / close valve 55 and a pressure gauge are interposed in the water pipe 36 connected to the liquid inlet 8.

  While the liquid (water) supplied to the nozzle 1 through the piping path and the spraying air composed of compressed air are constantly supplied, the pilot air is supplied when spraying and is stopped when spraying is stopped.

The operation of the two-fluid nozzle 1 of the first embodiment having the above-described structure will be described.
At the time of spraying from the two-fluid nozzle 1, water (liquid) to be supplied is supplied from the water pipe 36 to the liquid inlet 8 and compressed air is supplied from the compressed air pipe 37 to the spraying air inlet 7 through the branch pipe 37A. The air is supplied from the pilot air inlet 9 through the pipe 37B. As shown in FIG. 4, compressed air introduced into the cylinder housing chamber 5 from the pilot air introduction port 9 through the pilot air passage 25 is applied to the pressure receiving surface 11 s of the cylinder portion 11 to resist the spring force of the spring 15. The piston 12 is retracted, the air on the back side of the cylinder housing chamber 5 is released to the atmosphere from the vent hole 2h, the front end valve portion 13 is removed from the valve seat 22, and the liquid passage 23 is opened. Thus, the liquid flows from the liquid passage 23 into the inclined liquid passage 23 k of the mixing chamber 21, mixed with the compressed air that flows into the mixing chamber 21 from the spraying air passage 20, and sprayed from the nozzle 4.

  As described above, since the area of the pressure receiving surface 11 s of the piston 12 on which the compressed air acts is increased, the force for retracting the piston 12 increases, and the compressed air is applied to the piston 12 against the spring force of the spring 15. Simultaneously with the supply, the piston is instantaneously retracted to open the valve seat 22 and spray the gas-liquid mixture.

  When the spraying is stopped, the introduction of the compressed air into the pilot air inlet 9 is stopped, but the introduction of the liquid into the liquid inlet 8 and the introduction of the compressed air into the atomizing air inlet 7 are continued. Since the pressure by the compressed air on the pressure receiving surface 11 s of the piston 12 is eliminated, the cylinder portion 11 of the piston 12 is pushed forward by the spring 15 and the valve seat 22 is closed by the valve portion 13 to close the liquid passage 23.

  When the supply of compressed air is stopped, the liquid passage 23 is blocked and water is not sprayed without stopping the supply of water. When the supply of pilot air is stopped, the piston 12 can be advanced by the spring force of the spring 15 and the valve seat 22 can be instantaneously closed by the valve portion 13. In the valve closing operation, the rod portion 10 of the piston 12 has a small-diameter pin shape, so that the required driving force of the piston 12 is small and only the spring force of the spring 15 is required. Therefore, it is not necessary to apply to the spring pressure of the spring 15 the air pressure that presses the piston required by the conventional nozzle shown in FIG. Therefore, the piping of the compressed air to the back side of a piston can be made unnecessary.

  In addition, a rubber O-ring 26 is attached to the valve portion 13 at the tip of the rod portion of the piston 12, and when the valve seat 22 is closed, it is sealed with the O-ring 26, so that liquid leakage can be prevented. Moreover, since the rubber Y-packing 16 is attached, it is possible to prevent leakage of compressed air acting on the pressure receiving surface 11s of the piston 12.

  In particular, the nozzle 1 of the present invention is a nozzle having a piston 12 that opens and closes the liquid passage 23, and the piston rod portion 10 provided with the valve portion 13 at the tip is solid, as in Patent Documents 1 to 3 described above. Since the rod is not used as a sleeve for a liquid passage or an air passage, the rod portion 10 can be formed into a solid thin pin shape. As a result, the required driving force of the piston 12 can be reduced, and the area of the pressure receiving surface 11s of the cylinder portion 11 of the piston 12 that causes the rod portion 10 to protrude in the center can be increased. Therefore, the piston 12 can be instantaneously retracted by the compressed air applied to the pressure receiving surface 11s and can be instantaneously advanced by the spring 15 on the back side.

  In addition, since the hollow of the rod portion 10 of the piston 12 is not used as a liquid passage and the rod housing chamber 6 on the outer periphery of the rod portion 10 is used as a liquid passage, the diameter of the rod portion 10 of the piston is increased in order to increase the liquid flow rate. Since it is not necessary and can be made into a thin pin as described above, it is possible to reduce the size of the piston 12, the size of the spring 15 and the like, and the overall shape of the nozzle 1 can be greatly reduced.

  Furthermore, in the mixing chamber 21 of liquid and air, an annular inclined liquid passage 23k is provided in which the inclined surface 21b surrounding the liquid inflow side is reduced in diameter toward the mixed liquid outlet 21i, and the inclined liquid passage 23k is in the length direction. Since the channel cross-sectional area in the direction perpendicular to the axis is gradually reduced, the hydraulic pressure can be gradually increased. As described above, since the transverse orifice is not provided in the flow path, turbulent flow does not occur, and it is possible to reduce or prevent clogging due to adhesion of foreign matters in the liquid.

  The portion where the liquid passage 23 and the atomizing air passage 20 are mixed in the mixing chamber 21 may have the structure of the first modification shown in FIG. 5 and the second modification shown in FIG.

  In the first modification shown in FIG. 5, the small-diameter air passage 20d2 continuous to the front end of the central air passage 20b is an inclined air passage that gradually decreases in diameter toward the air injection port 20f at the front end. The peripheral wall 20c surrounding the small-diameter air passage 20d2 protruding to the center of the inflow side of the mixing chamber 21 is inclined in the diameter-reducing direction with the outer peripheral surface and inner peripheral surface facing the front end. As described above, the small-diameter air passage 20d2 that is inclined inside the inclined liquid passage 23k is provided on the inflow side in the mixing chamber 21, and both the outer liquid passage and the inner air passage gradually reduce the cross-sectional area of the liquid. Increasing pressure and air pressure. Since the other structure of the whole nozzle is the same as that of 1st Embodiment, description is abbreviate | omitted.

In the above structure, since a transverse orifice is not provided in the flow path, the flow path sandwiching the orifice does not expand, and there is no portion where turbulence occurs. As a result, it is possible to reduce or prevent the foreign matter in the liquid from adhering to the inner peripheral surface surrounding the liquid supply path and accumulating it.
Furthermore, air can be injected from the air injection port 20f into the center of the mixing chamber 21, and liquid can be sucked from the annular inclined liquid passage 23k on the inflow side outer periphery of the mixing chamber 21 by the injection pressure of the air. Therefore, the liquid on the outer periphery that flows in at high speed in the mixing chamber 21 can be collided and mixed with the air in the center to make the droplets finer. By miniaturizing the liquid in this way, coarse particles can be reduced in the jet fluid, and when the nozzle is used for humidification, cooling, gas suction, paint injection, incinerator injection, coarse particles Can solve the problem of inefficiency.

  In the second modification shown in FIG. 6, the inner surface of the peripheral wall surrounding the inclined small-diameter air passage 20d3 is provided with a first inclined portion 20n on the air injection port 20f side, and the second inclined portion 20m is provided at the rear end of the first inclined portion 20n. Are provided continuously. The second inclined portion 20m is inclined by 10 to 30 degrees with respect to the nozzle center axis L, and the first inclined portion 20n is inclined by 0 to 5 degrees with respect to the nozzle axis.

7 and 8 show a two-fluid nozzle 1-B according to a second embodiment of the present invention.
The two-fluid nozzle 1-B does not provide a spraying air inlet and a pilot air inlet separately, and is configured as one common air inlet 40. The front end of the air introduction port 40 communicates with the spraying air passage 20 and the rear end of the air introduction port 40 communicates with the pilot air passage 25-B. The compressed air that has passed through the pilot air passage 25 -B is introduced into the cylinder accommodating chamber 5 from the front opening of the cylinder accommodating chamber 5, and the compressed air acts on the pressure receiving surface 11 s of the cylinder 11.
The other configuration of the nozzle is substantially the same as that of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  The air system piping path and the liquid system piping path have a structure shown in FIG. The compressed air supplied to the nozzle 1-B as the atomizing air and the pilot air is supplied from the air compressor 50 through one compressed air pipe 37, and the compressed air pipe 37 is supplied with an air filter 51, a two-way solenoid valve 56, and an open / close valve. 57. After interposing a pressure gauge, it is connected to the air inlet 40. The liquid pipe is the same as that of the first embodiment, and an open / close valve 55 and a pressure gauge are interposed in the water pipe 36 connected to the liquid inlet 8.

  The spray air and pilot air consisting of the liquid (water) and compressed air supplied to the nozzle 1-B through the piping path simultaneously supply and stop supplying the sprayed and pilot compressed air, while the liquid is always used. Supply.

  In the same manner as the nozzle 1 of the first embodiment, the nozzle 1-B of the second embodiment pushes the pressure receiving surface 11s of the piston 12 with the compressed air and retracts it when supplying compressed air, thereby opening the valve seat 22 of the liquid passage. Spray. When spraying is stopped, the piston 12 is pressed by the spring 15 to advance, and the valve seat 22 of the liquid passage is closed to stop spraying.

  In the two-fluid nozzle of the second embodiment, since the two compressed air introduction ports required for the nozzle of the first embodiment are made one, it is not necessary to branch the compressed air piping, and the piping is simpler. Become.

DESCRIPTION OF SYMBOLS 1 Two-fluid nozzle 2 Body 4 Injection hole 5 Cylinder accommodation chamber 6 Rod accommodation chamber 7 Spraying air introduction port 8 Liquid introduction port 9 Pilot air introduction port 10 Rod part 11 Cylinder part 11s Pressure receiving surface 12 Piston 13 Valve part 15 Spring 20 Air passage 21 Mixing chamber 22 Valve seat 23 Liquid passage 25 Pilot air passage

Claims (7)

A piston for opening and closing a liquid passage, which is disposed in the body of the nozzle so as to be able to move back and forth along the central axis, has a solid rod part at the front part on the injection side and has a cylinder part at the rear part, A cylinder housing chamber for housing the part so as to freely move forward and backward,
A spring that presses against a rear end surface of the cylinder portion in the cylinder housing chamber and biases it in a valve closing direction;
A fluid passage that is provided in the middle of the passage with a valve seat that is opened and closed by a valve portion at the front end of the rod portion of the piston, and that communicates a mixing chamber at the front end of the passage and a liquid inlet opening on a side surface of the body; An air inlet opening on the side surface of the spraying air passage for communicating with the mixing chamber;
A pilot air passage that communicates an air inlet opening on the side of the body and a pilot air inlet at the front end of the cylinder housing chamber;
The piston is retracted by the air supplied to the pressure receiving surface of the front surface of the cylinder portion of the piston to open the valve seat of the liquid passage and mix and spray two fluids, while acting on the rear surface of the piston portion of the piston. A two-fluid nozzle configured to advance a piston with the spring and close the valve seat to stop spraying. The liquid passage communicating with the liquid introduction port opens into a rod housing chamber in which the rod portion of the piston moves forward and backward, and enters the mixing chamber via a valve seat of the liquid passage located at the front end of the rod housing chamber. Communication,
The spraying air passage communicating with the air introduction port communicates with the mixing chamber via an air passage provided on the injection side from the valve seat,
2. The two-fluid nozzle according to claim 1, wherein a vent hole is provided in a wall of the body surrounding the cylinder housing chamber housing the spring to release the air to the atmosphere. The air inlet is provided separately at a position close to the side surface of the body with a spray air inlet that communicates with the spray air passage and a pilot air inlet that communicates with the pilot air passage;
Alternatively, the two-fluid nozzle according to claim 1 or 2, wherein the number of the air inlets is one, and the atomizing air passage and the pilot air passage are communicated with the air inlet. At the center of the inflow side of the mixing chamber in the body of the nozzle, a peripheral wall surrounding the spraying air passage projects, and the front end of the liquid passage opens to the inflow side outer periphery of the mixing chamber,
The front end side outer peripheral surface of the peripheral wall surrounding the spraying air passage and the inner peripheral surface of the mixing chamber surrounding the front end side outer peripheral surface are inclined toward the front end in the direction of diameter reduction to reduce the diameter to the front end side of the liquid passage. The two-fluid nozzle according to any one of claims 1 to 3, wherein an annular inclined liquid passage is provided.   5. The two-fluid nozzle according to claim 4, wherein an inclined air passage is provided by inclining a front end side inner peripheral surface of a peripheral wall surrounding a spray air passage continuing to an air injection port at a tip of the spray air passage.   The spraying air passage continuing to the periphery of the air injection port includes a first inclined portion and a second inclined portion continuing to the first inclined portion, and the first inclined portion is 0 to 5 with respect to the nozzle axis. The two-fluid nozzle according to claim 5, wherein the second inclined portion is inclined by 10 to 30 degrees with respect to the nozzle axis. A mixing chamber for mixing the liquid introduced through the liquid passage into the body of the nozzle and the air introduced through the atomizing air passage;
At the center of the inflow side of the mixing chamber in the body of the nozzle, a peripheral wall surrounding the spraying air passage projects, and the front end of the liquid passage opens to the inflow side outer periphery of the mixing chamber,
A liquid passage on the inflow side of the mixing chamber in which a front end side outer peripheral surface of the peripheral wall surrounding the spraying air passage and an inner peripheral surface of the mixing chamber surrounding the front end side outer peripheral surface are inclined toward the front end in a diameter reducing direction. A two-fluid nozzle having an annular inclined liquid passage with a reduced diameter.

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