JP7502775B2 - Spray nozzle - Google Patents

Description

The present invention relates to a spray nozzle for spraying a gas-liquid mixture, which is a mixture of a liquid and a gas.

A known spray nozzle for spraying a gas-liquid mixture, which is a mixture of liquid and gas, has a configuration such as that disclosed in Non-Patent Document 1.

Asaba Co., Ltd. "Super 25 (for human power and power - Asaba Co., Ltd.)", [online], Asaba Co., Ltd., [searched on May 8, 2020], Internet <URL: https://www.asaba-mfg.com/part/スーパー25%e3%80%80g14/>

By using the spray nozzle disclosed in Non-Patent Document 1, the mixture of liquid and gas is stabilized and drift and scattering of the gas-liquid mixture sprayed from the spray nozzle can be suppressed, making it suitable for tasks such as spraying pesticides. However, there is an issue that the spray width becomes narrow when the gas-liquid mixture is sprayed at a low volume and low pressure.

The present invention was made to solve the above problems, and its purpose is to provide a spray nozzle that can spray a gas-liquid mixture over a wide area even when spraying a low volume and low pressure.

As a result of intensive research by the inventors to solve the above problems, the inventors have come up with the following configuration: That is, the present invention is a spray nozzle for spraying a gas-liquid mixture of liquid and air, comprising: a nozzle holder arranged on a base end side, which is a connecting side with a liquid supply pipe that supplies the liquid, and having an air introduction part for taking in the air into the liquid, an introduction path that communicates between the air introduction part and an external space and introduces external air into the air introduction part, and a mixing chamber for mixing the external air taken in by the air introduction part with the liquid to generate the gas-liquid mixture; a front spray plate attached to the front end side of the nozzle holder and having a slit formed therein, which is an injection port for the gas-liquid mixture supplied from the mixing chamber; and a nozzle holder disposed between the nozzle holder and the front spray plate, a nozzle core having a guide flow passage formed therein for guiding the gas-liquid mixture supplied from the mixing chamber toward the slit; and an orifice plate housed at the base end side of the nozzle holder and having a pinhole formed therein for injecting the liquid supplied from the liquid supply pipe into the air inlet, wherein the guide flow passage is formed in a shape such that a cross-sectional area of the flow passage gradually decreases as it proceeds from the base end side to the tip end side, and a buffer space is formed between the nozzle core and the tip injection plate in which the gas-liquid mixture supplied from the guide flow passage is temporarily stored before being sprayed from the slit.

This allows the gas-liquid mixture to be temporarily stored in a pressurized state in the buffer space before being sprayed from the slit, so that even when spraying the gas-liquid mixture at low volume and pressure, it can be sprayed over a wide area. This makes it possible to significantly reduce the labor burden when spraying a gas-liquid mixture, such as when spraying pesticides.

The slit is formed in a constricted portion where the tip side of the leading plate is convex, and the nozzle core has a disk placed on the nozzle holder, the guide passage formed in the disk, and a protrusion provided in an area outside the guide passage and entering the constricted portion, and it is preferable that the buffer space is formed by the disk and the protrusion of the nozzle core and the constricted portion of the leading plate.

This allows the nozzle to be formed by combining parts that make up a conventional spray nozzle, making it possible to provide a high-performance spray nozzle at a low cost.

By adopting the spray nozzle configuration of the present invention, the gas-liquid mixture can be temporarily stored in a pressurized state in the buffer space before being sprayed from the slit, so that even when spraying the gas-liquid mixture at low volume and pressure, it can be sprayed over a wide area. Therefore, when manually spraying a gas-liquid mixture, such as for spraying pesticides, the amount of liquid that the worker must carry can be significantly reduced, making it possible to significantly reduce the burden of work.

FIG. 2 is an exploded view of the spray nozzle according to the embodiment. FIG. 2 is a front view of the spray nozzle according to the embodiment. FIG. 2 is a plan view of the spray nozzle according to the embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an enlarged view of the base portion of FIG. 4 . FIG. 2 is an enlarged plan view of the nozzle core. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 6. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. 10 is a cross-sectional view taken along line XI-XI in FIG. 9. FIG. 2 is an explanatory diagram showing the internal structure of the nozzle core and the tip plate. FIG. 11 is an explanatory cross-sectional view showing a modified example of the guide flow path. 13 is an explanatory diagram showing a modified example of the nozzle core and the tip plate. FIG.

Below, an embodiment of a spray nozzle 100 according to the present invention will be described in detail with reference to the drawings. As shown in Figs. 1 to 3, the spray nozzle 100 in this embodiment comprises a nozzle holder 10, an orifice plate 20, a nozzle core 30, an O-ring 40 as a sealing member, a tip plate 50, and a nozzle cap 60.

The nozzle holder 10 has a main body 11, a first rib 12, a second rib 13, a base 14, and a male threaded portion 15. The main body 11 is formed as a cylindrical body having an internal space penetrating in the height direction. On the outer peripheral surface of the main body 11, a first rib 12 is arranged along the height direction of the main body 11, standing perpendicular to the radial outward direction of the main body 11. The first rib 12 is arranged at a plurality of locations at required intervals along the circumferential direction of the outer peripheral surface of the main body 11. In addition, at the intermediate position in the height direction of the first rib 12, a second rib 13 is arranged along the circumferential direction of the main body 11, standing perpendicular to the radial outward direction from the outer peripheral surface of the main body 11. By providing such a first rib 12 and a second rib 13 on the main body 11, the main body 11 can be provided with sufficient strength and reduced in weight.

A base portion 14 is formed on the base end side (connection side with the liquid supply pipe 70) of the main body portion 11. The base portion 14 has a flange portion 14A, a small diameter portion 14B, an introduction passage 14C, a connection portion 14D, and a base portion inner space 14E. The flange portion 14A is for holding a connector 80 that connects the liquid supply pipe 70 to the nozzle holder 10. The small diameter portion 14B is a portion formed with a smaller diameter than the flange portion 14A, and is integrated with the lower end portion of the first rib 12. In addition, an introduction passage 14C is formed on the outer circumferential surface of the small diameter portion 14B for introducing external air into an air introduction portion 17 (described later) formed inside the main body portion 11. In this embodiment, the introduction passage 14C is provided at two points spaced 180 degrees around the central axis of the main body portion 11, extending in a direction perpendicular to the radial outward direction from the central axis of the main body portion 11, and communicates the external space with the air introduction portion 17.

The bottom side of the base portion 14 is formed with a smaller diameter than the flange portion 14A, and is formed with a connecting portion 14D to which the liquid supply pipe 70 is connected. A recessed base portion inner space 14E is formed in the bottom surface of the connecting portion 14D. The base portion inner space 14E contains the orifice plate 20, which will be described later.

The tip (upper end) of the main body 11 is formed with a male threaded portion 15 having a cylindrical shape and a screw thread on its outer circumferential surface. An internal space 15A is formed inside the male threaded portion 15, and positioning protrusions 16 are provided at two equally spaced locations on the outer circumferential surface of the internal space 15A (the inner circumferential surface of the male threaded portion 15) so as to protrude toward the inside of the internal space 15A (the central axis of the male threaded portion 15 (not shown)).

As shown in Figures 4 and 5, the main body 11 is formed with a flow path space for passing the liquid supplied from the liquid supply pipe 70. This flow path space is formed in the following order from the base end side of the main body 11: base inner space 14E, air introduction section 17, flow path 18, enlarged diameter flow path 19A, and male threaded section inner space 15A. The base inner space 14E is connected to the internal space of the liquid supply pipe 70, and the enlarged diameter flow path 19A is connected to the male threaded section inner space 15A. In this embodiment, the mixing chamber 19 is formed by the enlarged diameter flow path 19A and the male threaded section inner space 15A, which are continuous in the flow path direction.

The air inlet 17, which is connected to the base inner space 14E, has an inlet passage communication space 17A in which the communication part 14F of the inlet passage 14C is formed, and a reduced diameter part 17B that is provided downstream of the inlet passage communication space 17A and gradually reduces in diameter as it proceeds downstream. The height position of the inlet passage communication space 17A is formed to be the same as the height position of the communication part 14F, which is the opening part in the inlet passage communication space 17A of the inlet passage 14C, and the inner diameter dimension of the inlet passage communication space 17A is formed to be the same dimension (cylindrical) in the height direction. The reduced diameter part 17B is intended to reliably guide the water injected into the inlet passage communication space 17A to the flow path 18 together with the outside air taken in from the inlet passage 14C, even if the central axis of the path of the water injected into the inlet passage communication space 17A does not coincide with the central axis of the main body part 11.

The orifice plate 20 housed in the base inner space 14E has a disk portion 21 that is circular in plan view, an upright injection portion 22 that rises from the center of the disk portion 21 to the top surface (tip side) of the disk portion 21, and a pinhole 23 formed on the top surface (tip side) of the upright injection portion 22. By housing such an orifice plate 20 in a fitted state in the base inner space 14E, which is the connecting portion with the liquid supply pipe 70, the flow rate of the liquid supplied from the liquid supply pipe 70 is increased in the base inner space 14E, and the liquid can be injected at high speed and in a pinpoint manner into the air introduction portion 17 that communicates with the base inner space 14E.

In addition, in this embodiment, the height position of the opening surface of the pinhole 23 of the upright injection portion 22 and the height position of the central axis of the introduction passage 14C (communication portion 14F) are the same. As described above, the introduction passage 14C is disposed at two locations equally spaced apart in the circumferential direction of the base portion 14 (nozzle holder 10, main body portion 11) when the spray nozzle 100 is viewed in a plan view.

The cylindrical flow passage 18 connected to the air inlet 17 is formed with an inner diameter dimension that is the same as the inner diameter dimension of the narrowest part of the narrowed diameter section 17B. This type of flow passage 18 prevents the external air taken in from the inlet 14C from flowing back through the flow passage 18, and supplies sufficient external air to the connected expanded diameter flow passage 19A (mixing chamber 19). It is also possible to prevent the gas-liquid mixture from flowing back from the expanded diameter flow passage 19A.

The expanding flow passage 19A is formed in an inverted truncated cone shape that gradually expands in diameter as it flows downstream, and is continuous with the male threaded internal space 15A. The diameter dimension of the narrowest diameter part (starting end) of the expanding flow passage 19A is formed to be larger than the inner diameter dimension of the flow passage 18. When spraying of the gas-liquid mixture begins, the water and external air that have passed through the flow passage 18 pass through the mixing chamber 19, collide with the lower surface of the nozzle core 30, and bounce back, mixing the water and the external air, which are temporarily stored in the mixing chamber 19. Even when the mixing chamber 19 is filled with water and external air, additional water and external air are still supplied from the flow passage 18, and the additionally supplied water and external air collide with the gas-liquid mixture stored in the mixing chamber 19, mixing the additionally supplied water and external air. In this way, a gas-liquid mixture in which the water and the external air are sufficiently mixed can be produced.

In addition, by storing the gas-liquid mixture in which the bubbles are finely divided in the space 15A inside the male thread portion, which is located immediately before the nozzle core 30 as in this embodiment, the flow rate of the gas-liquid mixture supplied to the leading nozzle plate 50 through the guide passage 36 of the nozzle core 30 can be increased even in low-volume, low-pressure sprays.

As shown in Figures 6 to 8, the nozzle core 30 in this embodiment has a disk 32, which is the main body, a positioning recess 34, a guide passage 36, and a protrusion 38. The disk 32 is formed with a diameter larger than the opening diameter of the male threaded portion internal space 15A, and the positioning recess 34 is formed on the underside of the disk 32 to match the position of the positioning protrusion 16, so that the positioning protrusion 16 and the positioning recess 34 fit together. The nozzle core 30 can be attached to the nozzle holder 10 (upper surface of the male threaded portion 15) in a predetermined direction depending on the position of the positioning protrusion 16.

In addition, the guide flow passage 36 in this embodiment is formed by two through holes that penetrate the disk 32 in the plate thickness direction as shown in FIG. 1. The two guide flow passages 36 are arranged on the diameter line of the disk 32, and when the nozzle core 30 is viewed in plan, the first straight line L1 (dashed line in FIGS. 1, 3, and 6) connecting the guide flow passages 36 is arranged so as to be parallel (on the same straight line) with the second straight line L2 (dotted line in FIGS. 1 and 3) connecting the communication parts 14F, which are the openings of the introduction passage 14C on the introduction passage communication space 17A side. The applicant's experiments have revealed that by adopting such an arrangement of the guide flow passage 36 and the introduction passage 14C (communication part 14F), the spray width from the slit 56 can be widened.

As shown in Figures 1 and 4, the guide flow passage 36 in this embodiment is formed so that the opening on the top side (tip side) is smaller than the opening on the bottom side (base end side) of the disk 32 in order to increase the flow rate of the gas-liquid mixture supplied to the leading plate 50. To explain in more detail, the guide flow passage 36 in this embodiment is formed in a shape (isosceles trapezoidal cross-sectional shape) in which the cross-sectional area of the flow passage gradually decreases as it progresses from the base end side to the tip end side. Note that, although the guide flow passage 36 is formed in an isosceles trapezoidal cross-sectional shape here, the guide flow passage 36 is not limited to an isosceles trapezoidal cross-sectional shape.

The protrusions 38 are erected at two locations on the upper surface (tip side) of the disk 32 in an area outside the guide flow passage 36, on the same line as the first line L1, and the upper portion of the protrusions 38 abuts against the inside of the leading jet plate 50 described later. In this embodiment, the protrusions 38 are formed in a parabolic shape that gradually increases in protruding height from the outer periphery of the disk 32 toward the center point of the disk 32, and are formed in a required diameter range from the outer periphery of the disk 32 to a position just before the outer periphery of the guide flow passage 36. The inner upright surface 38A of the protrusions 38 is formed in an upright surface that is perpendicular to the upper surface of the disk 32, and a planar arc surface portion is formed along the outer periphery of the guide flow passage 36.

The nozzle core 30 thus formed is mounted in a sealed state on the upper surface of the male thread portion 15 by the O-ring 40 as a sealing member that contacts the upper surface of the male thread portion 15 and the outer periphery of the nozzle core 30, the positioning protrusion 16, and the positioning recess 34. The arc surface portion in plan view is a clearance portion for the molding pin when forming the guide flow path 36.

On the nozzle core 30, a leading plate 50 as shown in Figs. 9 to 11 is placed. In the leading plate 50 in this embodiment, a throttling portion 54, a slit 56, and a thin portion 58 are formed on a base 52 formed in a disk shape. The throttling portion 54 is formed in a convex shape that protrudes upward (protrudes toward the tip of the spray nozzle 100) from other flat portions of the base 52 on the diameter line of the base 52 (on the same straight line as the arrangement direction of the guide flow passage 36) by drawing or the like. The protrusion 38 of the nozzle core 30 can enter the inner surface of the throttling portion 54 in this embodiment. In addition, as shown in Fig. 10, the shape of the rising portion 54A from the base 52 of the throttling portion 54 in this embodiment is formed to follow the outer surface shape of the protrusion 38 of the nozzle core 30, and the shapes of the throttling portion 54 and the protrusion 38 are formed so that they fit into the inner surface of the throttling portion 54.

In the center of the throttling section 54 in the longitudinal direction (the direction of the first straight line L1), a slit 56 is formed as an injection port for the gas-liquid mixture, arranged perpendicular to the longitudinal direction of the throttling section 54. In addition, a required range portion of the throttling section 54 including the portion where the slit 56 is formed is formed as a thin-walled portion 58 that is thinner than the thickness of the other portions of the throttling section 54. By forming such a thin-walled portion 58, the plate thickness at the opening edge of the slit 56 becomes thinner, and the frequency of the gas-liquid mixture breaking into droplets in this portion can be reduced. This prevents droplets from dripping from the opening edge of the slit 56, and even if droplets are formed, they leave the opening edge of the slit 56 at a small droplet stage, making it possible to reduce spray unevenness.

In addition, as shown in FIG. 10, the thin-walled portion 58 in this embodiment is formed as a curved surface that is concave toward the tip side (having an arc-shaped shape when viewed from the front), and the slit 56 is arranged at the bottom of the curved surface so as to cross the throttle portion 54 in a direction perpendicular to the curved surface. This makes the tip spray plate 50 thinnest at the opening edge of the slit 56. Such a thin-walled portion 58 is preferably formed by wire electric discharge machining. The thin-walled portion 58 formed by wire electric discharge machining is advantageous in that it is possible to eliminate the generation of burrs at the opening edge of the slit 56, preventing a reduction in the spray range of the gas-liquid mixture, and further reducing droplet formation.

Figure 12 is a cross-sectional view of the main part showing the state in which the leading plate 50 is fitted to the nozzle core 30. When the throttling portion 54 of the leading plate 50 is inserted (fitted) into the protrusion 38 of the nozzle core 30, a space is formed in the area surrounded by the disk 32, the inner upright surface 38A (protrusion 38), and the throttling portion 54. This space is used as a buffer space 39 for storing a predetermined amount of gas-liquid mixture in order to increase the flow rate of the gas-liquid mixture sprayed from the slit 56. By providing the buffer space 39 between the leading plate 50 and the nozzle core 30, the gas-liquid mixture supplied from the guide flow path 36 is not directly sprayed from the slit 56. By storing a predetermined amount of gas-liquid mixture in the buffer space 39 in this way, the momentum of the gas-liquid mixture sprayed from the slit 56 can be increased and the gas-liquid mixture can be further mixed.

As shown in Figures 1 and 4, the nozzle cap 60 is a cylindrical body with a tip formed into a narrow diameter portion 62, and the inner peripheral surface of the nozzle cap 60 is formed with a female thread 64 that screws into the male thread portion 15. By screwing the male thread portion 15 into the female thread 64 of the nozzle cap 60, the narrow diameter portion 62 presses the base 52 of the leading nozzle plate 50 against the upper surface of the male thread portion 15, elastically deforming the O-ring 40, and the nozzle core 30 and leading nozzle plate 50 can be fixed and held in a sealed state to the male thread portion 15.

As shown in Figs. 2 to 4, the connector 80 is a cylindrical body with a female thread 82 formed on the inner circumferential surface and a non-slip convex portion 84 formed on the outer circumferential surface. By screwing the male thread 74 formed on the connection end 72 of the liquid supply pipe 70 connected to the connection portion 14D of the base portion 14 into the female thread 82, the nozzle holder 10 and the liquid supply pipe 70 can be connected in a non-detachable state. Even when the connector 80 is screwed into the nozzle holder 10, the inner diameter dimension of the upper end 86 of the connector 80 is formed slightly larger than the outer diameter dimension of the base portion 14, so that the introduction passage 14C is not blocked and it is possible to prevent foreign matter from being sucked in from the introduction passage 14C.

The structure of the spray nozzle 100 in this embodiment has been described above. Next, a mechanism for supplying water as a liquid and external air as a gas to the spray nozzle 100 in this embodiment and spraying the gas-liquid mixture will be described. Water provided from a clean water supply or the like is supplied to the nozzle holder 10 from a liquid supply pipe 70. The cross-sectional area of the flow path of the water supplied to the nozzle holder 10 is reduced by the standing injection portion 22 of the orifice plate 20, and the flow rate of the water passing through the nozzle holder 10 is increased by passing through a pinhole 23 formed in the standing injection portion 22, thereby reducing the pressure of the surrounding space through which the water passes.

The height position of the opening surface of the pinhole 23 is set at the same height position as the communication part 14F, which is the opening of the inlet passage communication space 17A of the inlet passage 14C that takes in external air, as shown in Figures 4 and 5. In addition, since the communication parts 14F are arranged facing each other when the base part 14 (nozzle holder 10, main body part 11) is viewed in a plane, the horizontal velocity component of the external air taken in from the inlet passage 14C (communication part 14F) is offset in the inlet passage communication space 17A. As a result, the external air taken in the inlet passage communication space 17A by the pressure reduction effect of the water sprayed from the pinhole 23 is efficiently taken in together with the water into the reduced diameter part 17B and the flow path 18, and sufficient external air can be taken in for the amount of water supplied.

In this way, the water and external air taken into the nozzle holder 10 are reliably supplied from the reduced diameter section 17B to the expanded diameter flow path 19A, which is part of the mixing chamber 19, without flowing back through the cylindrical flow path 18. The water and external air taken in by the inlet passage communication space 17A are sent to the mixing chamber 19 at an increased flow rate by the reduced diameter section 17B and the flow path 18. The gas-liquid mixture sent to the expanded diameter flow path 19A collides with the nozzle core 30 housed in the male threaded portion space 15A, which is part of the mixing chamber 19, whereby the water and external air are mixed, and the gas-liquid mixture is temporarily stored in the male threaded portion space 15A.

The connection between the flow passage 18 and the expanded flow passage 19A is formed so that the inner diameter of the expanded flow passage 19A is larger, and the expanded flow passage 19A is formed so that the inner diameter gradually expands toward the downstream side. In the internal space of the expanded flow passage 19A formed in this shape, the water and external air additionally supplied from the flow passage 18 collide with the gas-liquid mixture already stored there, and mixing occurs due to sudden expansion loss. Furthermore, when water and external air are supplied from the flow passage 18, the gas-liquid mixture in the mixing chamber 19 flows sequentially from the guide flow passage 36 of the nozzle core 30 into the buffer space 39 formed inside the throttling portion 54 of the leading nozzle plate 50.

When the buffer space 39 is filled with the gas-liquid mixture, the gas-liquid mixture is sprayed in a fan shape from the slit 56. In this embodiment, the gas-liquid mixture sprayed from the spray nozzle 100 is temporarily stored in the buffer space 39 as described above, and is sprayed from the slit 56 in a state of increased pressure. In other words, a thoroughly mixed gas-liquid mixture can be sprayed vigorously in a fan shape from the slit 56.

By using the spray nozzle 100 of this embodiment in this way, the bubble volume per unit volume of the sprayed gas-liquid mixture can be significantly improved compared to the conventional method, and the amount of water used when spraying the chemical solution can be significantly reduced. In other words, the gas-liquid mixture can be sprayed over a wide area with a small amount of water using a single-head nozzle structure, significantly improving work efficiency. In addition, particularly when spraying herbicides, this is particularly advantageous in that the particle size of the sprayed gas-liquid mixture does not become excessively small, preventing it from being blown into unintended areas by the wind during spraying.

And because a thin-walled portion 58 is formed in the required range including the portion where the slit 56 is formed, even when the gas-liquid mixture is sprayed, the amount of particles of the gas-liquid mixture that gather on the opening edge of the slit 56 can be kept as small as possible. This is advantageous in that dripping of droplets from the slit 56 is prevented, and the uniformity of the spray density of the gas-liquid mixture in the spray range can be increased.

The spray nozzle 100 according to the present invention has been described above based on an embodiment, but the configuration of the spray nozzle 100 according to the present invention is not limited to the embodiment described above. For example, in the spray nozzle 100 in the embodiment described above, a mixture of external air and water is exemplified as the gas-liquid mixture, but the gas-liquid mixture is not limited to a mixture of external air and water, and can be a gas-liquid mixture of external air and herbicide, or a gas-liquid mixture of a known gas and liquid.

In this embodiment, two guide channels 36 are provided in the nozzle core 30, but three or more guide channels 36 may be provided. These guide channels 36 may be arranged in a straight line, and may have a shape in which the cross-sectional area of the channel gradually decreases in the flow direction. In this embodiment, the guide channels 36 are described as being formed in a so-called linear tapered shape as shown in FIG. 8, but it is also possible to adopt a bell-mouth shape as shown in FIG. 13(A) or a convex shape in which a large diameter section and a small diameter section are directly connected as shown in FIG. 13(B).

In addition, in this embodiment, the slits 56 are described as being orthogonal to the straight line connecting the multiple guide channels 36 in the horizontal direction, but are not limited to this. The slits 56 may be arranged in any manner so long as they are horizontally intersecting the straight line connecting the multiple guide channels 36.

In addition, in this embodiment, the protrusion 38 of the nozzle core 30 is described as fitting into the throttling portion 54 of the leading nozzle plate 50, but this is not limited to the above. The protrusion 38 only needs to be able to enter the throttling portion 54 and abut against the base end side of the throttling portion 54, and it is also possible to adopt a configuration in which the buffer space 39 is formed without the protrusion 38 fitting into the throttling portion 54.

In addition, although the embodiment has been described in which the first rib 12 and the second rib 13 are arranged on the outer peripheral surface of the main body 11, if the main body 11 has sufficient mechanical strength, the arrangement of at least one of the first rib 12 and the second rib 13 can be omitted.

In addition, in this embodiment, the introduction passage 14C is described as being formed in such a manner that the axis of the introduction passage 14C is formed perpendicular to the fluid flow direction in the introduction passage communication space 17A at two locations equally spaced apart in the circumferential direction of the introduction passage communication space 17A, but this is not limited to this form. The two introduction passages 14C can also be disposed on a tangent to the outer peripheral surface of the introduction passage communication space 17A.

Furthermore, the height of the opening of the small diameter portion 14B on the outer surface of the inlet passage 14C is the same as the height of the communication portion 14F, which is the opening in the inlet passage communication space 17A, but the inlet passage 14C does not have to be formed horizontally in the base portion 14. In addition, a configuration in which the height position of the inlet passage 14C in the base portion 14 is made different in the extension direction of the inlet passage 14C so that the inlet passage 14C is inclined (non-orthogonal state) with respect to the flow direction of the fluid in the inlet passage communication space 17A and communicates with it can be adopted. Furthermore, a configuration in which the height position of the communication portion 14F of each inlet passage 14C is made different can be adopted. This is advantageous in that the external air taken in by the air inlet portion 17 becomes swirling, and the mixing of the liquid and the external air in the mixing chamber 19 located downstream can be promoted.

In addition, in this embodiment, the nozzle core 30 is described as having a protrusion 38 that enters the throttling portion 54 of the leading plate 50, but this is not limited to this form. As shown in FIG. 14, a protrusion entry portion 52A consisting of a through hole can be formed in the base 52 of the leading plate 50, and the nozzle core 30 can have a protrusion 38 that can enter the protrusion entry portion 52A. In this case, the buffer space 39 is formed by the space surrounded by the disk 32 of the nozzle core 30 and the throttling portion 54 of the leading plate 50. Furthermore, a form can be adopted in which the protrusion entry portion 52A consisting of a through hole shown in FIG. 14 is changed to the protrusion entry portion 52A consisting of a concave portion.

In addition, in this embodiment, a single-head spray nozzle 100 is described, but the spray nozzle 100 of the present invention can also be applied to each of the multi-head nozzles of a chemical spray vehicle.

It is also possible to adopt a configuration in which the various modified examples of the embodiments described above are appropriately combined.

10 nozzle holder,
11 Main body portion, 12 First rib, 13 Second rib,
14 Base portion, 14A Flange portion, 14B Small diameter portion, 14C Introduction passage,
14D connecting portion, 14E base portion inner space, 14F communication portion,
15 Male thread portion, 15A Male thread portion internal space,
16 Positioning protrusion,
17 air introduction portion, 17A introduction passage communication space, 17B reduced diameter portion,
18 flow path,
19 mixing chamber, 19A expanding flow path,
20 Orifice plate,
21 disk portion, 22 standing injection portion, 23 pinhole,
30 nozzle core,
32 disk, 34 positioning recess, 36 guide flow path,
38 protrusion, 38A inner upright surface,
39 Buffer Space,
40 O-ring (sealing member),
50 Front jet plate,
52 base portion, 52A protrusion entry portion,
54: narrowed portion, 54A: rising portion,
56 slit, 58 thin wall portion,
60 Nozzle cap,
62 Thin diameter portion, 64 Female thread,
70 liquid supply pipe,
72 Connection end, 74 Male thread,
80 Linker,
82 female thread portion, 84 convex portion, 86 upper end portion,
100 spray nozzle,
L1: First straight line, L2: Second straight line

Claims (2)

A spray nozzle for spraying a gas-liquid mixture of liquid and air,
a nozzle holder disposed on a base end side which is a connection side with a liquid supply pipe which supplies the liquid, the nozzle holder having an air inlet portion which takes in the air into the liquid, an inlet path which communicates between the air inlet portion and an external space and which takes in external air into the air inlet portion, and a mixing chamber which mixes the external air taken in by the air inlet portion with the liquid to generate the gas-liquid mixture;
a front nozzle plate attached to a front end side of the nozzle holder and having a slit formed therein which is an injection port for the gas-liquid mixture supplied from the mixing chamber;
a nozzle core disposed between the nozzle holder and the front nozzle plate, the nozzle core having a guide passage formed therein for guiding the gas-liquid mixture supplied from the mixing chamber toward the slit;
an orifice plate that is accommodated on the base end side of the nozzle holder and has a pinhole formed therein for injecting the liquid supplied from the liquid supply pipe into the air introduction portion,
The guide flow passage is formed in a shape in which a flow passage cross-sectional area gradually decreases from the base end side to the tip end side,
A spray nozzle characterized in that a buffer space is formed between the nozzle core and the front nozzle plate, in which the gas-liquid mixture supplied from the guide passage is temporarily stored before being sprayed from the slit. The slit is formed in a convex-shaped narrowing portion of the tip side of the front nozzle plate,
the nozzle core has a circular plate mounted on the nozzle holder, the guide passage formed in the circular plate, and a protrusion provided in an outer region of the guide passage and protruding into the throttle portion,
2. The spray nozzle according to claim 1, wherein the buffer space is defined by the disk and the protrusion of the nozzle core and the throttle portion of the tip plate.

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