JP7616677B2 - Spray nozzle - Google Patents

Description

The present invention relates to a spray nozzle used to spray liquids such as pesticides and water.

Many spray nozzles used to spray liquids such as pesticides and water are equipped with a cylindrical nozzle body with a liquid passageway formed through the axis and a male thread formed on the outer periphery of the tip, a nozzle tip member such as a nozzle plate or nozzle tip with a nozzle hole through which liquid supplied to the liquid passageway of the nozzle body is sprayed as mist droplets, and a cap that is screwed to the tip of the nozzle body and fixes the nozzle tip member to the tip of the nozzle body with the nozzle hole exposed (for example, see Patent Document 1).

JP 2018-51427 A

In spray nozzles like the one described above, the cap's fastening to the nozzle body gradually loosens due to vibrations during use, and this loosening can cause the nozzle tip components, such as the spray plate and nozzle tip, to rotate. If the circumferential position of the nozzle tip component changes, the mist particles sprayed from the nozzle may point in an unintended direction, which can result in the liquid not being sprayed efficiently on the target object.

One way to deal with this is to periodically retighten the cap, but with large sprayers (such as boom sprayers with multiple spray nozzles attached at regular intervals along the length of a long boom), retightening the cap can be a tedious task.

The objective of the present invention is to provide a cap that is screwed to the nozzle body of a spray nozzle to secure the nozzle tip member, and that has a simple structure and can be stably prevented from loosening.

In order to solve the above problems, the present invention provides a spray nozzle comprising a cylindrical nozzle body with a liquid passage formed through the axial center and a male thread formed on the outer periphery of the tip, a nozzle tip member with a nozzle hole for spraying liquid supplied to the liquid passage of the nozzle body, and a cap that is screwed to the tip of the nozzle body and fixes the nozzle tip member to the tip of the nozzle body with the nozzle hole exposed, the cap has an engagement portion on the inner periphery closer to the screw-in tip side than the female thread that screw-connects with the male thread of the nozzle body, with a circumferentially continuous mountain-shaped protrusion having inclined surfaces on both sides in the circumferential direction, and the nozzle body has an engagement piece that engages with the engagement portion of the cap and is displaceable radially inward by elastic deformation on the outer periphery closer to the axial center than the male thread.

In the above configuration, when the nozzle tip member is fixed to the nozzle body, as the cap is screwed to the tip of the nozzle body, the engaging portion of the cap comes into contact with the engaging piece of the nozzle body, but if the force used to rotate the cap is increased to a certain extent, the protrusion of the engaging portion displaces the engaging piece radially inward by elastic deformation and overcomes the engaging piece, allowing the cap to be tightened smoothly. Then, when the tightening is completed and the engaging portion and the engaging piece are engaged, even if a force is applied in a direction that loosens the cap due to vibration or the like, the cap can be stably prevented from loosening as long as the force is not large enough to cause the protrusion of the engaging portion to overcome the engaging piece.

The mechanism for preventing the cap from loosening in this way is composed only of an engagement part consisting of multiple mountain-shaped protrusions formed on the inner circumference of the screw-in tip side of the cap, and an engagement piece that is provided on the outer circumference of the nozzle body so that it can be displaced radially inward, so the structure is simple and does not increase the number of parts in the entire spray nozzle.

Here, the engaging piece can be made up of a support portion that extends obliquely from the outer periphery of the nozzle body in the radial direction, and a protrusion that is continuous with the tip side of the support portion and fits into the valley between adjacent protrusions in the circumferential direction of the cap. By using this engaging piece, it becomes easy to adjust the design of the resistance to loosening of the cap (ease of attachment and removal).

Furthermore, if the engaging pieces are provided in multiple locations at equal intervals around the circumference of the nozzle body, the force that rotates the cap is applied to the cap in a balanced manner, which is preferable.

As described above, the spray nozzle of the present invention is designed so that when the cap is screwed onto the nozzle body, an engagement portion consisting of multiple mountain-shaped protrusions formed on the inner circumference of the screwed-in tip side of the cap engages with an engagement piece provided on the outer circumference of the nozzle body so that it can be displaced radially inward, and therefore the cap can be stably prevented from loosening with a simple structure. Therefore, rotation of the nozzle tip member due to vibration during use can be prevented, and liquid can always be sprayed accurately onto the target object without having to periodically retighten the cap.

FIG. 1 is an external perspective view of a spray nozzle according to an embodiment; FIG. 2 is an exploded perspective view of a main part of the spray nozzle of FIG. 1; FIG. 2 is a longitudinal sectional front view of the spray nozzle of FIG. 4 is a cross-sectional view taken along line IV-IV of FIG.

The embodiment of the present invention will be described below with reference to Figures 1 to 4. As shown in Figures 1 to 3, this spray nozzle includes a cylindrical nozzle body 1 having a liquid passage 1a formed through the axial center and a male thread 1b formed on the outer periphery of the tip, a cap 2 screwed to the tip of the nozzle body 1, a disk-shaped nozzle plate (nozzle tip member) 3 attached to the nozzle body 1 by the cap 2, an annular seal member 4 sealing between the nozzle plate 3 and the nozzle body 1, a core 5 arranged between the tip surface of the nozzle body 1 and the nozzle plate 3, an orifice plate 6 arranged in the liquid passage 1a near the rear end of the nozzle body 1, a cylindrical packing 7 that is in close contact with the rear end surface of the nozzle body 1, a filter 8 arranged inside the packing 7, a holder 9 that holds the rear end of the nozzle body 1, a union nut 10 that connects the holder 9 to the nozzle body 1, and a lock nut 11 that prevents the union nut 10 from loosening. Between the nozzle body 1 and the cap 2, a mechanism 12 is provided to prevent the cap 2 from loosening relative to the nozzle body 1 (hereinafter referred to as the "loosening prevention mechanism").

The nozzle body 1 has a pair of arc-shaped core receivers 1c on the inner circumference of the large-diameter tip of the liquid passage 1a, which protrude slightly from the tip surface of the nozzle body 1, and a pair of pin holes 1d on the step surface that forms the bottom of the large-diameter tip of the liquid passage 1a. In addition, an air introduction hole 1e is provided in the center in the longitudinal direction, penetrating from the outer circumferential surface to the liquid passage 1a, and a flange 1f for engaging a union nut 10 is provided on the outer periphery of the rear end.

The cap 2 has a female thread 2a formed on its inner circumference that threads into the male thread 1b of the nozzle body 1, and an inner flange 2b at its tip. Then, by threading the cap to the nozzle body 1 with the nozzle plate 3 pressed against the tip surface of the nozzle body 1 via the seal member 4, the outer peripheral edge of the nozzle plate 3 is tightened by the inner flange 2b, and the nozzle plate 3 is fixed to the nozzle body 1 together with the seal member 4 and the core 5.

The nozzle plate 3 is formed with a bulging portion 3a that has a U-shaped cross section and extends in the radial direction, and a nozzle hole 3b that sprays liquid supplied to the liquid passage 1a of the nozzle body 1 is opened in the longitudinal center of the bulging portion 3a. The nozzle hole 3b is exposed by the cap 2 and is fixed to the tip of the nozzle body 1.

The sealing member 4 is a general-purpose O-ring, which is compressed between the nozzle plate 3 and the tip surface of the nozzle body 1 when the cap 2 is tightened, creating a liquid-tight seal between the nozzle plate 3 and the nozzle body 1.

The core 5 regulates the flow of the liquid that has passed through the liquid passage 1a after being mixed with air sucked in through the air inlet 1e of the nozzle body 1, and has two flow paths 5a that direct the liquid toward the spray plate 3. A pair of positioning pins 5b are provided on the back surface (the surface facing the nozzle body 1), and a pair of protrusions 5c are provided on the periphery of the front surface (the surface facing the spray plate 3). Each positioning pin 5b is inserted into the pin hole 1d of the nozzle body 1, and is assembled in a state where a part of the periphery of the back surface abuts against the core receiver 1c of the nozzle body 1. During this assembly, each protrusion 5c of the core 5 fits into a groove on the back surface (the surface facing the core 5) of the bulge 3a of the spray plate 3, thereby positioning the core 5 and the spray plate 3 in the circumferential direction.

The holder 9 has a liquid introduction passage 9a that communicates with the liquid passage 1a of the nozzle body 1 through the inner space of the packing 7, and is a member that is connected to a liquid supply source (not shown) such as an external liquid guide tube with its tip holding the rear end of the nozzle body 1 and the outer periphery of the packing 7.

The union nut 10 has an inner flange 10a at its tip, and when it is screwed into the tip of the holder 9, the inner flange 10a tightens the flange 1f of the nozzle body 1, connecting the nozzle body 1 to the holder 9, and in this state is prevented from loosening by the lock nut 11.

Of the above-mentioned components, the spray plate 3, orifice plate 6, and filter 8 are made of stainless steel, the seal member 4 and packing 7 are made of rubber, and the other components are made of resin. The resin components can be replaced with other materials that are resistant to the liquid to be sprayed, but it is preferable to use resin for the nozzle body 1, as described below.

The locking mechanism 12 that locks the cap 2 against the nozzle body 1 is provided with an engagement portion 13 on the inner circumference closer to the screw-in tip than the female thread 2a of the cap 2, with a mountain-shaped protrusion 13a having inclined surfaces on both sides in the circumferential direction, as shown in Figures 3 and 4, and a pair of engagement pieces 14 that engage with the engagement portion 13 of the cap 2 are provided at centrally symmetrical positions on the outer circumference closer to the axial center than the male thread 1b of the nozzle body 1, as shown in Figures 2 to 4.

Each engagement piece 14 of the nozzle body 1 is composed of a support portion 14a that extends obliquely from the outer periphery of the nozzle body 1 in the radial direction, and a convex portion 14b that is continuous with the tip side of the support portion 14a and fits into the valley between adjacent protrusions 13a in the circumferential direction of the cap 2, and is provided in a state in which it can be displaced radially inward of the nozzle body 1 by the bending deformation of the support portion 14a. Here, each engagement piece 14 is formed of resin integrally with the nozzle body 1, and is designed so that an appropriate amount of displacement occurs due to the bending deformation of the support portion 14a.

By adopting the above-mentioned anti-loosening mechanism 12, when the spray plate 3 is fixed to the nozzle body 1 together with the seal member 4 and the core 5, as the cap 2 is screwed to the tip of the nozzle body 1, the engagement portion 13 of the cap 2 comes into contact with the protrusions 14b of each engagement piece 14 of the nozzle body 1. However, if the force with which the cap 2 is rotated is increased to a certain extent at this time, the protrusions 13a of the engagement portion 13 bend the support portions 14a of the engagement pieces 14 and displace them radially inward, overcoming the protrusions 14b of the engagement pieces 14, so that the cap 2 can be tightened smoothly. Then, after the cap 2 is sufficiently tightened, the convex portions 14b of the engagement pieces 14 enter the valleys between the protrusions 13a adjacent to each other in the circumferential direction of the cap 2, completing the tightening.

When the cap 2 has been tightened in this way and the engagement piece 14 of the nozzle body 1 is engaged with the engagement portion 13 of the cap 2, even if a force is applied in a direction that loosens the cap 2 due to vibration or the like, the cap 2 can be stably prevented from loosening as long as the force is not large enough to cause the protrusion 13a of the engagement portion 13 to overcome the convex portion 14b of the engagement piece 14.

On the other hand, when replacing the spray plate 3, simply rotating the cap 2 in the opposite direction to when it was tightened with a certain amount of force will cause the protrusion 13a of the engagement part 13 to overcome the convex part 14b of the engagement piece 14, allowing the cap 2 to be smoothly loosened and removed from the nozzle body 1.

This spray nozzle has the above-mentioned configuration, in which liquid supplied from an external liquid source to the liquid inlet passage 9a of the holder 9 flows through the filter 8 inside the packing 7 into the liquid passage 1a of the nozzle body 1, passes through the orifice plate 6 and is mixed with air introduced from the air inlet hole 1e, then is straightened as it passes through the flow path 5a of the core 5, and is sprayed in the form of mist droplets from the nozzle 3b of the nozzle plate 3.

The cap 2 that secures the spray plate 3 to the nozzle body 1 is prevented from loosening from the nozzle body 1 by an anti-loosening mechanism 12, and is designed not to rotate easily due to vibrations during use. Therefore, liquid can be sprayed accurately onto the target object at all times without having to periodically retighten the cap 2, eliminating the need for the cumbersome task of retightening the cap as in the past.

In addition, the anti-loosening mechanism 12 is composed only of an engagement portion 13 consisting of multiple mountain-shaped protrusions 13a formed on the inner circumference of the cap 2 and an engagement piece 14 provided on the outer circumference of the nozzle body 1, so the structure is simple and does not increase the number of parts in the entire spray nozzle.

Furthermore, the engagement piece 14 of the nozzle body 1 has a support portion 14a that extends obliquely from the outer periphery of the nozzle body 1 in the radial direction, so the design of the resistance to loosening of the cap 2 (ease of attachment and removal) can be easily adjusted by changing the length and cross-sectional area of the support portion 14a.

It is sufficient that at least one engagement piece is provided on the outer periphery of the nozzle body, but it is preferable to provide multiple engagement pieces at equal intervals around the circumference of the nozzle body as in this embodiment, so that the force rotating the cap is applied to the cap in a balanced manner.

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

For example, the engagement piece is not limited to that in the embodiment, but may be any piece that can be displaced radially inward of the nozzle body by elastic deformation.

The present invention can also be applied to spray nozzles incorporating nozzle tip components (e.g., nozzle tips, etc.) other than the nozzle plate as in the embodiment.

1 Nozzle body 1a Liquid passage 1b Male thread 2 Cap 2a Female thread 3 Spray plate (nozzle tip member)
3b nozzle 12 anti-loosening mechanism 13 engagement portion 13a projection 14 engagement piece 14a support portion 14b protrusion

Claims (3)

A spray nozzle comprising: a cylindrical nozzle body having a liquid passage formed through its axial center and a male screw formed on the outer periphery of its tip; a nozzle tip member having an orifice for spraying liquid supplied to the liquid passage of the nozzle body; and a cap that is screwed to the tip portion of the nozzle body and fixes the nozzle tip member to the tip of the nozzle body with the orifice exposed,
The cap is provided with an engagement portion on an inner periphery on the screw-in tip side of the female thread that is screwed into the male thread of the nozzle body, the engagement portion having a circumferentially continuous mountain-shaped protrusion having inclined surfaces on both circumferential sides,
A spray nozzle characterized in that the nozzle body has an engagement piece that engages with an engagement portion of the cap and is provided on the outer periphery of the nozzle body toward the axial center side of the male thread, the engagement piece being displaceable radially inward by elastic deformation. The spray nozzle according to claim 1, characterized in that the engagement piece is composed of a support portion that extends obliquely from the outer periphery of the nozzle body in the radial direction, and a protrusion that is continuous with the tip side of the support portion and fits into a valley between adjacent protrusions in the circumferential direction of the cap. The spray nozzle according to claim 1 or 2, characterized in that the engagement pieces are provided in a plurality at equal intervals around the circumference of the nozzle body.

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