Spray nozzle

Abstract

To provide a spray nozzle which can switch a spray amount and does not easily cause a drift phenomenon.SOLUTION: In a spray nozzle 10, a tip side body 20 and a rear end side body 30, which constitute a nozzle body 1, are so connected as to be non-rotatable relatively and movable in an axial direction, and an open hole 28 in a radial direction is provided on a tip side with respect to a first orifice part 27 in the middle of a flow channel 2 of the tip side body 20. By rotating an operation cylinder 7 which is screwed to an outer periphery of the tip side body 20 and is so attached to the rear end side body 30 as to be non-movable in the axial direction and moving the tip side body 20 in the axial direction, a bottom surface of an engagement hole 22a of the tip side body 20 opens and closes a peripheral hole 34b of a second orifice part 34 formed integrally with a tip of the rear end side body 30, thereby switching between a state that a small amount of liquid mixed with air introduced into the flow channel 2 through the open hole 28 from an exterior is sprayed and a state that a large amount of the same is sprayed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a spray nozzle used for spraying liquids such as pesticides and water. [Background technology]

[0002] When spraying liquids such as pesticides or water, the liquid can be atomized and sprayed efficiently by connecting a spray nozzle to a liquid supply source such as a liquid pressure hose. However, the spray nozzle must be used according to the purpose of the liquid spray. For example, a small spray amount is used when spraying liquid on a part of the leaf surface of a crop, and a large spray amount is used when spraying liquid on the entire leaf surface of a crop. Therefore, if the spray amount required changes depending on the purpose, the spray nozzle connected to the liquid supply source must be changed to a different type, and the workload of changing the spray nozzle increases, especially for sprayers such as large boom sprayers.

[0003] In contrast, if a spray nozzle with a structure that allows the spray amount to be switched is used, the work of replacing the spray nozzle can be omitted or the frequency of replacement can be reduced. For example, Patent Document 1 proposes such a spray nozzle that allows the spray amount to be switched.

[0004] As shown in Fig. 6, the spray nozzle of Patent Document 1 includes a cylindrical nozzle body 51 having a flow passage 52 formed through its axial center, a nozzle plate 53 attached to the tip of the nozzle body 51 and having a nozzle hole 53a at the center, a tip cap 54 for attaching the nozzle plate 53 to the nozzle body 51, a base tube 55 connected to the rear end of the nozzle body 51 and connected to a liquid pressure feed hose which is an external liquid supply source, a connection cap 56 for attaching the base tube 55 to the nozzle body 51, a cylindrical operation cover 57 disposed on the radial outside of the nozzle body 51, a core 58 disposed at the tip of the flow passage 52 of the nozzle body 51, and an orifice plate 59 for partitioning the flow passage 52 of the nozzle body 51. The orifice plate 59 has a central hole 59a and a plurality of peripheral holes 59b around it. Here, the tip refers to the downstream end in the flow direction of the liquid, and the rear end refers to the upstream end in the flow direction of the liquid (the same applies below).

[0005] The nozzle body 51 is divided into a tip side body 70 and a rear end side body 80 connected to the base tube 55, and the tip side body 70 is further divided into a tip section 71 to which the injection plate 53 and the core 58 are attached, and an intermediate section 72 to which the orifice plate 59 is attached. The intermediate section 72 of the tip side body 70 is provided with a through hole 72a penetrating from the outer circumferential surface to the flow path 52 on the tip side of the attachment position of the orifice plate 59, and a male thread is provided on the outer circumferential surface on the rear end side of the through hole 72a. The tip section 71 and the intermediate section 72 of the tip side body 70 are integrated by a concave-convex engagement, and the rear end side body 80 is integrated with the base tube 55 by a concave-convex engagement. The tip portion of the rear end body 80 is fitted into the rear end inner circumference of the intermediate portion 72 of the tip end body 70 so as to be relatively non-rotatable but movable in the axial direction, and the tip surface of the rear end body 80 and the peripheral hole 59b of the orifice plate 59 face each other in the axial direction.

[0006] The operation cover 57 is attached to the nozzle body 51 so as to be rotatable about the axis thereof, with a female screw provided on its inner peripheral surface being screwed into a male screw of an intermediate portion 72 of the tip side body 70 constituting the nozzle body 51. Also, a flange portion 57a ​​provided on the rear end portion is sandwiched between the rear end portion of the rear end side body 80 constituting the nozzle body 51 and the connecting cap 56 in a state in which the two are immovable relative to each other in the axial direction. As a result, when the operation cover 57 is rotated, the tip side body 70 of the nozzle body 51 moves axially together with the orifice plate 59 relative to the operation cover 57 and the rear end side body 80 of the nozzle body 51.

[0007] A communication passage 60 is formed between the outer peripheral surface of the tip side body 70 of the nozzle body 51 and the inner peripheral surface of the operation cover 57, extending in the axial direction from the tip side of the operation cover 57 and connecting the outside to the through hole 72a of the tip side body 70. The communication passage 60 has a bent portion 60a midway, and an O-ring 61 is disposed near the rear end side of the bent portion 60a.

[0008] This conventional spray nozzle has the above-mentioned configuration, and when the operation cover 57 is rotated in one direction to move the tip side body 70 of the nozzle body 51 together with the orifice plate 59 axially toward the rear end side, opening the communication passage 60 and bringing the orifice plate 59 into close contact with the tip face of the rear end side body 80 to close the peripheral hole 59b of the orifice plate 59, the liquid supplied to the flow passage 52 from the rear end side of the nozzle body 51 passes through the central hole 59a of the orifice plate 59, and is mixed with air introduced from the outside through the communication passage 60 and the through hole 72a of the nozzle body 51 into the flow passage 52, and is sprayed from the nozzle hole 53a of the spray plate 53. At this time, a spray pattern with a large spray particle size and a small spray amount is obtained.

[0009] On the other hand, when the operation cover 57 is rotated in the reverse direction to move the tip side body 70 of the nozzle body 51 together with the orifice plate 59 axially toward the tip side, the communication passage 60 is closed by the O-ring 61, and the orifice plate 59 is separated from the tip surface of the rear end body 80 to open the peripheral holes 59b of the orifice plate 59, the liquid supplied to the flow passage 52 from the rear end side of the nozzle body 51 passes through the central hole 59a and each peripheral hole 59b of the orifice plate 59 and is sprayed from the nozzle hole 53a of the spray plate 53 without being mixed with air. At this time, a spray pattern with a small spray particle size and a large spray amount is obtained.

[0010] That is, with this spray nozzle, by rotating the operating cover 57 attached to the nozzle body 51, it is possible to switch between a state in which a small amount of liquid containing air is sprayed and a state in which a large amount of liquid without air is sprayed. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2005-319365 A Summary of the Invention [Problem to be solved by the invention]

[0012] However, with the conventional spray nozzles described above, when used in a large-volume spray state without mixing in air, the spray droplet size becomes small and is prone to drift (the phenomenon in which the sprayed liquid scatters outside the intended area), making them unsuitable for spraying herbicides, etc.

[0013] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a spray nozzle that is capable of switching the spray amount and is less susceptible to drift. [Means for solving the problem]

[0014] In order to solve the above problems, the spray nozzle of the present invention comprises a cylindrical nozzle body having a flow passage formed through its axial center, a nozzle plate attached to the tip of the nozzle body and having a nozzle hole in the center, and an actuating cylinder disposed radially outside the nozzle body, the nozzle body being configured such that a tip side body to which the nozzle plate is attached and a rear end side body connected to an external liquid supply source are connected together so as to be relatively unrotatable about the axis but movable in the axial direction, and the tip side body is fitted into the tip of the rear end side body. a first orifice portion having a central hole disposed on the axis of the flow passage further forward than the engagement hole, a through hole penetrates from an outer circumferential surface further forward than the first orifice portion to the flow passage, and a male screw is formed on an outer circumferential surface further rearward than the through hole, and a second orifice portion is provided at the tip of the rear end side body, having a central hole disposed on the axis of the flow passage and peripheral holes disposed therearound, and facing a bottom surface of the engagement hole of the tip end side body, and the working cylinder is provided on its inner circumferential surface. The screw is screwed into the male thread of the tip side body, and is attached to the tip side body so as to be rotatable about the axis, and is attached to the rear end side body so as to be rotatable about the axis but immovable in the axial direction. When the tip side body is moved toward the rear end side by rotating the working cylinder in one direction and the bottom surface of the engagement hole is brought into contact with the second orifice portion, the central hole of the second orifice portion communicates with the flow path of the tip side body, and the peripheral holes are closed by the bottom surface of the engagement hole, and the working cylinder is rotated in one direction to move the tip side body toward the rear end side. When the tube is rotated in the opposite direction to move the tip side body toward the tip side and move the bottom surface of the engagement hole away from the second orifice portion, the central hole and peripheral holes of the second orifice portion communicate with the flow path of the tip side body, and liquid supplied to the flow path from the rear end side of the rear end body passes through the second orifice portion and the first orifice portion of the tip side body, and then is mixed with air introduced into the flow path from the outside through the through hole of the tip side body and sprayed from the nozzle of the spray plate.

[0015] According to the above configuration, by simply rotating the actuator attached to the nozzle body, it is possible to easily switch between spraying a small amount of liquid and spraying a large amount of liquid. Moreover, since the sprayed liquid has a large atomized particle size due to the inclusion of air, the occurrence of drift can be effectively suppressed.

[0016] In the above configuration, it is preferable that the second orifice portion of the rear end body is provided with an annular protrusion protruding from the periphery of its central hole toward the flow path of the tip side body, and that the annular protrusion is adapted to fit into the rear end of the flow path of the tip side body when the bottom surface of the engagement hole of the tip side body abuts against the second orifice portion. In this way, even if the bottom surface of the engagement hole of the tip side body does not come into full contact with the second orifice portion when the tip side body is moved toward the rear end, the liquid that has passed through the peripheral hole of the second orifice portion is less likely to flow into the flow path of the tip side body, thereby preventing an unintended increase in the amount of spray when a small amount is being sprayed.

[0017] Here, if the outer peripheral surface of the annular protrusion of the rear end body and the inner surface of the rear end of the flow path of the tip side body are formed as tapered surfaces of the same shape, the annular protrusion can more smoothly enter the rear end of the flow path of the tip side body when the tip side body moves toward the rear end. Effect of the Invention

[0018] As described above, the spray nozzle of the present invention is designed to open and close the peripheral hole of the second orifice by rotating the actuator cylinder to move the tip body in the axial direction, so that it can easily switch between spraying a small amount of liquid and spraying a large amount of liquid. Moreover, the spray particle size of the liquid can be increased by mixing in air, so the occurrence of drift can be effectively suppressed. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a spray nozzle according to an embodiment in use; [Diagram 2] FIG. 2 is an exploded perspective view of the spray nozzle of FIG. [Diagram 3] A longitudinal sectional front view of the spray nozzle in Figure 1 (when spraying a small amount) [Figure 4] Cross-sectional view taken along line IV-IV in Figure 3. [Diagram 5] FIG. 2 is a longitudinal sectional front view showing the state in which the tip side body of the spray nozzle of FIG. 1 is moved in the axial direction (large amount spraying state) [Figure 6] A partial cross-sectional front view of a conventional spray nozzle (when spraying a small amount) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 5. Fig. 1 shows a state in which a spray nozzle 10 of the embodiment is connected to liquid guide pipes (branch pipes) P provided at a predetermined interval in the longitudinal direction of a boom B of a boom sprayer, which is an external liquid supply source. Here, although not shown, the liquid guide pipe P of the boom B has a male thread formed on the outer periphery on the tip side for connecting the spray nozzle 10, and a pair of notches for preventing the spray nozzle 10 from rotating are provided at the tip.

[0021] As shown in Figures 2 to 4, this spray nozzle 10 includes a cylindrical nozzle body 1 having a flow path 2 formed therethrough at its axial center, a spray plate 3 attached to the tip of the nozzle body 1, a tip cap 4 for attaching the spray plate 3 to the nozzle body 1, a connection cap 5 and a lock cap 6 for connecting the nozzle body 1 to a liquid guide pipe P of the boom B, an actuating cylinder 7 disposed radially outside the nozzle body 1, a core 8 disposed at the tip of the flow path 2 of the nozzle body 1, and a U-shaped slide pin 9 for restricting the axial movement of the actuating cylinder 7 relative to the nozzle body 1, as described later. Note that Figures 2 to 4 are drawn upside down from Figure 1, with the upward direction being the liquid spray direction (the same applies to Figure 5 described later).

[0022] The nozzle body 1 is made by connecting a tip side body 20, to which the nozzle plate 3 and the core 8 are attached, and a rear side body 30, which is connected to a liquid guide tube P, so that they cannot rotate about the axis but can move axially relative to each other, as will be described later. Furthermore, the tip side body 20 is divided into a body tip portion 21 and a body intermediate portion 22.

[0023] The tip portion 21 of the tip side main body 20 has a flow passage outlet 2a formed at the position where the core 8 is attached, and the tip portion of the main body intermediate portion 22 is fitted into the axial hole 21a which gradually expands in diameter from the step surface which forms the bottom of the flow passage outlet 2a toward the rear end face so as to be immovable and immovable in the axial direction.

[0024] A pair of arc-shaped core receivers 23 are provided on the inner periphery of the flow passage outlet 2a of the main body tip 21 in a state of slightly protruding from the tip face of the main body tip 21, and a pair of core fixing recesses 21b extending in the axial direction from the stepped face of the flow passage outlet 2a communicate with the axial hole 21a. A male thread 24 that screws into the tip cap 4 is provided on the outer periphery of the main body tip 21.

[0025] The tip cap 4 has an inner flange 4a on the inner circumference at the tip side, and with the O-ring 11 and spray plate 3 overlapping the tip surface of the main body tip portion 21, it is screwed into the male thread 24 of the main body tip portion 21, thereby tightening the outer peripheral edge of the spray plate 3 with the inner flange 4a, sealing the space between the spray plate 3 and the main body tip portion 21 with the O-ring 11, and attaching the spray plate 3 and core 8 to the main body tip portion 21.

[0026] The nozzle plate 3 is formed with a bulging portion 3a extending in the radial direction and having a U-shaped cross section, and a nozzle hole 3b extending in the width direction is formed in the center of the bulging portion 3a in the longitudinal direction.

[0027] Core 8 regulates the flow of liquid that has flowed up to flow path outlet 2a, and has a pair of holes 8a that direct the liquid toward spray plate 3. In addition, a pair of positioning pins 8b are provided on the back surface (the surface facing main body tip 21), and a pair of protrusions 8c are provided on the periphery of the front surface (the surface facing spray plate 3). Each positioning pin 8b is inserted into a core fixing recess 21b in main body tip 21, and is assembled in a state where part of the periphery of the back surface abuts against core receiver 23 in main body tip 21.

[0028] In addition, when the core 8 is attached to the main body tip portion 21 with the tip cap 4 together with the spray plate 3 and the O-ring 11, each protrusion 8c on the front side of the core 8 fits into a groove on the back side (the surface facing the core 8) of the bulge 3a of the spray plate 3, thereby positioning the core 8 and the spray plate 3 in the circumferential direction.

[0029] The main body intermediate part 22 of the tip side main body 20 has a tapered part 25 tapered in the middle of the part inserted into the axial hole 21a of the main body tip part 21, and a plurality of convex parts 26 are provided at equal intervals in the circumferential direction on the outer periphery rearward of the tapered part 25. The tapered part 25 is press-fitted into the inner periphery of the axial hole 21a of the main body tip part 21, and each convex part 26 is fitted into a plurality of axial grooves 21c provided on the inner periphery of the main body tip part 21, so that the main body intermediate part 22 and the main body tip part 21 are integrated. An O-ring 12 is incorporated between the outer periphery tipward of the tapered part 25 of the main body intermediate part 22 and the inner periphery of the main body tip part 21 to seal between them.

[0030] The main body intermediate part 22 is provided with an engagement hole 22a in which the tip part of the rear end side main body 30 fits into the large diameter part at the rear end, and a first orifice part 27 having a central hole 27a arranged on the axis of the flow path 2 is integrally formed on the tip side of the engagement hole 22a. The flow path 2 from the center of the engagement hole 22a to the central hole 27a of the first orifice part 27 is formed with a tapered surface whose inner surface widens toward the rear end. A pair of through holes 28 penetrating from the outer peripheral surface to the flow path 2 are provided on the tip side of the first orifice part 27 so as to face each other across the flow path 2. The vicinity of the outer opening of the through hole 28 is cut out larger than the opening, making it easier for air to flow into the through hole 28 from the outside of the main body intermediate part 22.

[0031] In addition, a male thread 29 that screws into the actuator cylinder 7 is provided on the outer peripheral surface of the large diameter portion of the main body intermediate portion 22 rearward of the through hole 28, and a pair of notches 22b are provided in the rear end portion for fitting with the rear end main body 30 so as to be unable to rotate relative to the rear end main body 30.

[0032] The rear end body 30 has a small diameter at the tip, and a first annular groove 31 is provided on the outer periphery of the small diameter portion for incorporating an O-ring 13 that seals between the rear end body 30 and the intermediate body portion 22, and a second annular groove 32 is provided on the outer periphery of the axial center portion for engaging with a slide pin 9 as described below.

[0033] In addition, a pair of protrusions 33 are provided on the outer periphery of the small diameter tip portion, and by fitting the small diameter tip portion into the engagement hole 22a of the main body intermediate portion 22 with each protrusion 33 fitting into the notch 22b of the main body intermediate portion 22, the tip side body 20 and the rear end side body 30 are connected relative to each other so as to be unable to rotate around the axis but able to move axially.

[0034] The small-diameter tip portion is integrally formed with a second orifice portion 34 having a central hole 34a disposed on the axis of the flow path 2 and peripheral holes 34b disposed around the central hole 34a and facing the bottom surface of the engagement hole 22a of the main body intermediate portion 22. The second orifice portion 34 is provided with an annular protrusion 34c protruding from the periphery of the central hole 34a toward the flow path 2 of the main body intermediate portion 22. The outer circumferential surface of the annular protrusion 34c is formed as a tapered surface having the same shape as the inner surface of the rear end portion of the flow path 2 of the main body intermediate portion 22, and is adapted to fit into the rear end portion of the flow path 2 of the main body intermediate portion 22 when the bottom surface of the engagement hole 22a of the main body intermediate portion 22 abuts against the second orifice portion 34 as described below.

[0035] Furthermore, a flange 35 for engaging the connecting cap 5 is provided on the outer periphery of the rear end of the rear end side main body 30, and a pair of anti-rotation projections 36 are provided on the rear end side of the flange 35.

[0036] The connecting cap 5 has an inner flange 5a on the inner periphery at the tip end side thereof. Although not shown, the rear end body 30 is connected to the liquid guide tube P by screwing the rotation-preventing protrusion 36 of the rear end body 30 into the notch of the liquid guide tube P and engaging with the male thread of the liquid guide tube P, whereby the flange 35 of the rear end body 30 is tightened by the inner flange 5a, thereby connecting the rear end body 30 to the liquid guide tube P.

[0037] In addition, the locking cap 6 is attached to the rear end side of the connecting cap 5 so that it cannot rotate around the axis and cannot move in the axial direction relative to the connecting cap 5, and prevents the connecting cap 5 from loosening when the rear end main body 30 is connected to the liquid guide tube P as described above.

[0038] The working cylinder 7 is attached to the tip side main body 20 so as to be rotatable about its axis by threadingly engaging a female thread 7a provided on its inner peripheral surface with a male thread 29 on the outer peripheral surface of the main body intermediate portion 22.

[0039] In addition, the working cylinder 7 is formed so that the outer circumferential surface becomes larger in diameter in three stages from the front end to the rear end, and a plurality of vanes 7b are provided on the outer periphery of the small diameter portion at the front end and the intermediate portion so as to extend in the axial direction to facilitate rotational operation.

[0040] The inner circumferential surface of the actuator 7 on the tip side of the female thread 7a faces the outer circumferential surface of the tip side main body 20 with a small radial gap therebetween. As a result, a communication passage 37 is formed between the outer circumferential surface of the tip side main body 20 and the inner circumferential surface of the actuator 7, extending in the axial direction from the tip side of the actuator 7 and connecting the outside with the through hole 28 of the tip side main body 20.

[0041] Further, the large diameter rear end portion of the actuating cylinder 7 is provided with two horizontal holes 7c into which the pair of arms 9a of the slide pin 9 are respectively inserted, and a circumferential groove 7d is provided between the openings of the two horizontal holes 7c on the arm insertion side. When the actuating cylinder 7 is attached to the rear end main body 30 and each arm 9a of the slide pin 9 is inserted into the horizontal hole 7c, the center portion of the arm 9a partially enters the second annular groove 32 of the rear end main body 30. At this time, the arm connecting portion 9b connecting the arms 9a of the slide pin 9 fits into the circumferential groove 7d of the actuating cylinder 7, and at the same time, the claws 9c provided at the tip of each arm 9a engage with the periphery on the side opposite to the insertion side of the horizontal hole 7c.

[0042] As a result, the actuator cylinder 7 is attached to the rear end body 30 so as to be rotatable about the axis but immovable in the axial direction. Here, the tip side body 20 which is screw-coupled to the actuator cylinder 7 is connected to the rear end body 30 so as to be immovable about the axis but immovable in the axial direction, as described above, when the actuator cylinder 7 is rotated, the tip side body 20 moves in the axial direction.

[0043] The spray nozzle 10 has the above-mentioned configuration, and when the tip-side body 20 is moved toward the rear end by rotating the actuator 7 in one direction and the bottom surface of the engagement hole 22a is brought into contact with the second orifice portion 34 of the rear-end body 30, the central hole 34a of the second orifice portion 34 communicates with the flow path 2 of the tip-side body 20 and the peripheral hole 34b is closed by the bottom surface of the engagement hole 22a (the state of Figs. 3 and 4). On the other hand, when the tip-side body 20 is moved toward the tip side by rotating the actuator 7 in the opposite direction and the bottom surface of the engagement hole 22a is separated from the second orifice portion 34, the central hole 34a and the peripheral hole 34b of the second orifice portion 34 communicate with the flow path 2 of the tip-side body 20, and a larger amount of liquid is sent to the flow path 2 of the tip-side body 20 than in the state of Figs. 3 and 4 (the state of Fig. 5).

[0044] In either of the above states, the liquid supplied to the flow path 2 from the rear end side of the rear end body 30 passes through the second orifice 34 and the first orifice 27 of the front end body 20, then mixes with air introduced from the outside through the communication passage 37 and the through hole 28 of the front end body 20 into the flow path 2, passes through the core 8, and is sprayed from the nozzle 3b of the nozzle plate 3. The liquid sprayed from the nozzle 3b forms a flat spray pattern that is thin in the longitudinal direction of the bulge 3a of the nozzle plate 3 and spreads in a fan shape along a plane perpendicular to that direction.

[0045] That is, this spray nozzle 10 can easily switch between spraying a small amount of liquid and spraying a large amount of liquid by simply rotating the actuating cylinder 7. Moreover, since it sprays liquid with air mixed in, regardless of the amount to be sprayed, and a large spray size is obtained, the drift phenomenon is unlikely to occur, making it suitable for spraying herbicides, etc.

[0046] In addition, when the tip side body 20 is moved toward the rear end to spray a small amount, the annular protrusion 34c of the second orifice portion 34 smoothly fits into the rear end of the flow path 2 of the tip side body 20. Therefore, even if the bottom surface of the engagement hole 22a of the tip side body 20 is not in full contact with the second orifice portion 34, liquid that has passed through the peripheral hole 34b of the second orifice portion 34 is less likely to flow into the flow path 2 of the tip side body 20, thereby preventing an unintended increase in the amount of spray.

[0047] In addition, since the first orifice portion 27 is integrally formed with the middle portion 22 of the tip-side body 20, and the second orifice portion 34 is integrally formed with the rear-side body 30, the number of parts is reduced and assembly is easier than when the orifice plates that serve the functions of each of the orifice portions 27, 34 are formed separately and attached to the tip-side body and the rear-side body.

[0048] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope and meaning equivalent to the claims.

[0049] For example, the tip side main body does not necessarily have to be divided into a main body tip portion and a main body intermediate portion as in the embodiment, but may be formed as a single unit. [Explanation of symbols]

[0050] 1 Nozzle body 2 Flow Path 3 spout plate 3b spout 4 Tip cap 5 Connecting Cap 6 Lock Cap 7. Working cylinder 7a Female thread 8 Core 9 Slide pin 10 Spray nozzle 20 Tip side body 21 Main body tip 22 Middle part of main body 22a Engagement hole 27 First orifice 27a center hole 28 Through hole 29 Male thread 30 Rear end body 34 Second orifice section 34a center hole 34b Peripheral hole 34c Annular protrusion B Boom P liquid conduit

Claims

1. The nozzle includes a cylindrical nozzle body having a flow passage formed through its axial center, a nozzle plate attached to a tip of the nozzle body and having a nozzle hole at its center, and an actuating cylinder disposed radially outward of the nozzle body, the nozzle body is a front end body to which the nozzle plate is attached and a rear end body connected to an external liquid supply source, the front end body and the rear end body being connected to each other so as to be non-rotatable about an axis and movable in an axial direction; the tip-side body has an engagement hole into which the tip portion of the rear-end body is fitted, a first orifice portion is provided tip-side from the engagement hole and having a central hole disposed on the axis of the flow path, a through hole extends from an outer circumferential surface tip-side from the first orifice portion to the flow path, and a male thread is formed on an outer circumferential surface rear-side from the through hole, a second orifice portion is provided at a tip of the rear end body, the second orifice portion having a central hole disposed on the axis of the flow passage and peripheral holes disposed therearound, the second orifice portion facing a bottom surface of the engagement hole of the tip end body; the working cylinder is attached to the tip side body so as to be rotatable about an axis thereof by a female screw provided on an inner circumferential surface of the working cylinder being screw-coupled with a male screw of the tip side body, and is attached to the rear end side body so as to be rotatable about an axis thereof but not movable in the axial direction, When the tip-side body is moved toward the rear end side by rotating the working cylinder in one direction and the bottom surface of the engagement hole is brought into contact with the second orifice portion, the central hole of the second orifice portion communicates with the flow path of the tip-side body and the peripheral holes are closed by the bottom surface of the engagement hole, When the working cylinder is rotated in the reverse direction to move the tip side body toward the tip side and move the bottom surface of the engagement hole away from the second orifice portion, the central hole and the peripheral hole of the second orifice portion communicate with the flow path of the tip side body, the liquid supplied to the flow path from the rear end side of the rear end side body passes through the second orifice portion and the first orifice portion of the front end side body, and is then mixed with air introduced from the outside into the flow path through a through hole of the front end side body, and is then sprayed from the nozzle of the spray plate, a second orifice portion of the rear end body having a ring-shaped protrusion protruding from the periphery of its central hole toward the flow path of the tip side body, and when the bottom surface of the engagement hole of the tip side body abuts against the second orifice portion, the ring-shaped protrusion fits into the rear end of the flow path of the tip side body.

2. 2. The spray nozzle according to claim 1, wherein an outer circumferential surface of the annular projection of the rear body and an inner surface of the rear end portion of the flow passage of the front body are formed with tapered surfaces of the same shape.

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