Mist Nozzle

Abstract

To provide a mist nozzle that has a simple structure, can stably generate fine mist even with a low pressure / low air capacity, and facilitates adjustment of a generation amount of mist.SOLUTION: A mist nozzle includes: a nozzle body 100 having a liquid discharge part 140 having a liquid discharge port 144, and a holding part 150 having a liquid supply passage 120, a gas discharge port 162 and a gas supply passage 160 and connected to the other end portion of the liquid discharge part 140; and a cap 180 having an injection hole portion 182 and detachably mounted on the nozzle body 100. When the cap 180 is mounted on the nozzle body 100, a gas injection part 166 connected to the gas discharge port 162 and a space part 170 are disposed, the liquid discharge port 144 is positioned on the concentric circle with the injection hole portion 182 and on an upstream side of liquid with respect to the outer end portion in the axial direction, the gas discharge port 162 is positioned on a downstream side of liquid with respect to the liquid discharge port 144, and a mixed body of liquid and gas is injected from the injection hole portion 182.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a nozzle that mixes a gas and a liquid to atomize and spray the liquid, a so-called mist nozzle, and particularly to an external mixing type mist nozzle.

Background Art

[0002] As one of the spray nozzles used for spraying and atomizing chemical liquids and paints, there is a mist nozzle. Mist nozzles include a type (internal mixing type) that separately introduces a gas (e.g., air) and a liquid (e.g., water) into the mist nozzle and mixes them inside the mist nozzle to atomize the liquid, and a type (external mixing type) that separately introduces a gas and a liquid into the nozzle and mixes them at the tip (spray outlet portion) of the mist nozzle. For any type, it is extremely important to make the spray pattern uniform and stably generate mist.

[0003] Patent Document 1 discloses a liquid agent spraying device in a backpack power sprayer, in which a hose made of a flexible material and a mist nozzle communicating with the hose are arranged along a hollow long support rod integrally coupled to a liquid supply pipe. In this device, during the spraying operation, the pressurized air generated in the fan case by a fan rotated by an engine drive reaches the mist nozzle through a bent pipe and a hose, while the chemical liquid in the chemical liquid tank is caused to flow into the mist nozzle through the liquid supply pipe by driving a mist pump, so that the chemical liquid is atomized in the mist nozzle by the pressurized air and sprayed from the tip of the mist nozzle.

[0004] Patent Document 2 discloses a mist nozzle that sprays a chemical solution over a wide area by causing water or a chemical solution ejected from the nozzle opening of the nozzle body to collide with a deflector positioned with a slight gap in front of it and atomizing it. In this device, the support arm that is attached to the nozzle body and supports the deflector is composed of a single thin elastic wire having a deflector support straight portion located on a line perpendicular to the injection center line of the nozzle opening, and both clip portions that are respectively extended to both ends of the deflector support straight portion and can be detachably fitted to the outer peripheral surface of the nozzle body.

[0005] Patent Document 3 discloses a mist head that generates sufficient negative pressure around the entire circumference of the nozzle discharge port and can spray evenly from the nozzle discharge port. In this device, in a mist head comprising a head body having a cylindrical shape for flowing an air current and a mist nozzle having a body portion having a nozzle discharge port for discharging a chemical solution located at the tip within the head body, a recessed portion is provided around the nozzle discharge port on the side portion along the flow direction of the air current of the body portion on the side where the flow of the air current on the rear side is blocked by the body portion.

[0006] Patent Document 4 discloses a mist nozzle that can suppress the generation of energy loss due to the orthogonal collision of a pressurized gas and a liquid and inject a mist atomized at high speed. In this device, a liquid suction port for sucking a liquid is provided on the center line of the injection flow path, and a plurality of gas discharge ports for discharging a gas are provided concentrically with the liquid suction port outside the liquid suction port. An inner atomization region is formed inside the plurality of concentric gas discharge ports to form a vortex and atomize the liquid droplets, and the middle portion of the injection flow path is widened to the outside of the plurality of gas discharge ports to form an outer atomization region that forms a vortex and atomizes the liquid droplets outside the plurality of concentric gas discharge ports, thereby improving the cleaning ability and cooling ability of the mist nozzle.

[0007] Non-Patent Document 1 discloses mist nozzles with different orifice diameters that can be selected according to the purpose of the mist, the installation height of the nozzle, the environment of the installation location, etc. In this case, in order to prevent the expansion of the holes due to wear, the spray holes are made of stainless steel and the body is made of brass, or both the spray holes and the body are made of stainless steel.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0009]

Non-Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0010] As described above, various mist nozzles have been proposed in order to achieve ideal mist generation and improve handling properties. However, their structures and usage methods are still complex.

[0011] In the case of what is disclosed in Patent Document 1, it is not intended to improve the nozzle itself, and it is necessary to newly provide a fan in order to forcibly introduce pressurized air. For this reason, the weight of the liquid application device increases, and the manufacturing cost and the like also increase.

[0012] In the case of what is disclosed in Patent Document 2, it requires fine assembled parts such as a deflector, fixing screws, and support arms. For this reason, difficulties arise in terms of durability and maintenance, and it is not something that anyone can easily manage and use.

[0013] In the case of what is disclosed in Patent Document 3, it is necessary to generate sufficient negative pressure around the entire circumference of the nozzle discharge port. For this reason, it is necessary to newly provide a special recess on the side portion along the flow direction of the air flow in the body portion of the mist nozzle. Also, it is necessary to provide a support portion for supporting the mist nozzle on the mist ejection head body.

[0014] In the case of what is disclosed in Patent Document 4, the internal structure of the nozzle is complex, and the opening portion of the mist injection port is exposed to the outside.

[0015] Even in the case of what is disclosed in Non-Patent Document 1, the internal structure of the nozzle is complex.

[0016] The present invention has been made in consideration of the above circumstances, and aims to provide a mist nozzle having a simple and compact structure, capable of stably generating fine mist even at low pressure and low air volume, and with easy adjustment of the mist generation amount.

Means for Solving the Problems

[0017] The mist nozzle of the present invention has the following configuration in order to achieve the above object.

[0018] (1) A nozzle body having a cylindrical liquid discharge portion provided with a liquid discharge port on one end side and a holding portion connected to the other end side of the liquid discharge portion, and a cap provided with an ejection hole portion penetrating through the outer surface portion and the inner surface portion and detachably attached to the nozzle body. The holding portion has a liquid supply path that connects to the other end side of the liquid discharge portion and supplies liquid to the liquid discharge portion, a gas discharge port from which gas is discharged, and a gas supply path that supplies gas to the gas discharge port. When the cap is attached to the nozzle body, A gas ejection part communicating with the gas ejection port, and a space part surrounded by the inner surface of the cap and the nozzle body and communicating with the ejection hole part and the gas ejection part are provided. The liquid ejection port is concentric with the ejection hole part and is located on the upstream side of the liquid with respect to the outer end part in the axial direction of the ejection hole part. The gas ejection port is located on the downstream side of the liquid with respect to the liquid ejection port. A mist nozzle configured such that a mixture of the liquid ejected from the liquid ejection port and the gas ejected from the gas ejection part is ejected from the injection hole part.

[0019] (2) The mist nozzle according to (1) above, wherein the liquid ejection part is made of metal or alloy.

[0020] (3) The mist nozzle according to (1) or (2) above, wherein the liquid ejection port has an outer diameter (Φ) of 0.2 mm or more and 1.0 mm or less and an inner diameter (Φ) of 0.1 mm or more and 0.9 mm or less.

[0021] Further, the mist nozzle of the present invention is a mist nozzle that atomizes and ejects a liquid with a gas, and includes a liquid supply path provided in a resinous nozzle body for supplying the liquid, a metal injection part provided at the tip of the liquid supply path so as to be detachable and injecting the liquid, a gas supply path provided in the nozzle body for supplying and injecting gas in the same direction as the injection direction of the liquid by the injection part, and a resin cap detachably attached to the nozzle body so as to surround the gas supply path and the injection part, and having an ejection hole part through which the gas from the gas supply path and the liquid from the injection part are mixed and ejected as mist. When the cap is attached to the nozzle body, the injection part is configured to be located inside the cap without being exposed outside the cap.

[0022] According to the above configuration, it has a simple and compact structure, enables stable generation of fine mist even at low pressure and low air volume, and has a useful effect that the adjustment of the mist generation amount is easy.

[0023] Also, according to the above configuration, it is excellent in durability, practical, and excellent in terms of productivity and economy.

Effect of the Invention

[0024] The mist nozzle of the present invention has a simple structure and can stably generate fine mist even at low pressure and low air volume. Further, the mist nozzle of the present invention can easily adjust the mist generation amount.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

[0026] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. In the present specification, members and elements having the same configuration or the same function are denoted by the same reference numerals, and repeated detailed description thereof will be omitted.

[0027] The mist nozzle 10 according to the present embodiment is a mist nozzle that atomizes and injects water (liquid) with air (gas). The mist nozzle 10 includes a nozzle body 100 and a cap 180 that is detachably attached to the nozzle body 100.

[0028] The nozzle body 100 includes a cylindrical liquid discharge part 140 provided with a liquid discharge port 144 on one end side, and a holding part 150 connected to the other end side of the liquid discharge part 140. The holding part 150 is provided with a gas discharge port 162 through which gas is discharged, and a liquid supply path 120 that is connected to the other end side part of the liquid discharge part 140 to supply liquid to the liquid discharge part 140, and a gas supply path 160 that supplies gas to the gas discharge port 162 are provided inside. The cap 180 is provided with an ejection hole part 182 that penetrates the outer surface part and the inner surface part of the cap 180.

[0029] When the cap 180 is attached to the mist nozzle body 100, that is, when the cap 180 is attached to the mist nozzle body 100, the mist nozzle 10 is provided with a gas ejection part 166 that communicates with the gas discharge port 162 and ejects the gas discharged from the gas discharge port 162, and a space part 170 surrounded by the inner surface part of the cap 180 and the nozzle body 100. The space part 170 communicates with the ejection hole part 182 and the gas ejection part 166. Also, in this state, the liquid discharge unit 140 will be at a position that satisfies the following two conditions. · In the X-axis direction of FIG. 1, the liquid discharge port 144 is located on the concentric circle of the ejection hole portion 182. · In the Y-axis direction of FIG. 1, the liquid discharge port 144 is located on the upstream side of the liquid with respect to the axially outer end portion E1 of the ejection hole portion 182. Also, in the present embodiment, the liquid discharge port 144 is located between the axially outer end portion E1 and the axially inner end portion E2 of the ejection hole portion 182 in the Y-axis direction of FIG. 1.

[0030] In the mist nozzle 10 having the above configuration, the gas supplied from the gas supply passage 160 and discharged from the gas discharge port 162 is ejected from the gas ejection portion 166 and flows toward the space portion 170. At this time, the flow velocity of the gas on the downstream side of the gas ejection portion 166 increases. The gas flowing into the space portion 170 with an increased flow velocity partially swirls inside the space portion 170 and heads toward the injection hole portion 182. At this time, the gas flows toward the downstream side of the gas through the gap between the liquid discharge unit 140 and the inner peripheral surface of the injection hole portion 182 and around the liquid discharge port 144. As a result, the differential pressure generated between the upstream side and the downstream side of the gas of the injection hole portion 182 becomes larger, and the gas flow velocity on the downstream side of the injection hole portion 182 further increases. Therefore, even when the gas supplied to the gas supply passage 160 is at low pressure and low air volume, the mist nozzle 10 can create a negative pressure state in the downstream region of the injection hole portion 182, that is, the liquid downstream region of the liquid discharge port 144. And since the liquid discharge port 144 is located on the upstream side of the liquid with respect to the axially outer end portion E1 of the ejection hole portion 182, the liquid can be discharged from the liquid discharge port 144 with a low-pressure and low-air-volume gas due to the above negative pressure, and a mixture of gas and liquid can be efficiently ejected from the injection hole portion 182 while atomizing the liquid. As a result, while simplifying the structure of the mist nozzle 10, it is possible to stably generate fine mist even with low pressure and low air volume. That is, in the mist nozzle 10, the flow velocity of the gas filled in the space portion 170 is increased in the gap between the ejection hole portion 182 and the liquid discharge portion 140 (liquid discharge port 144), and this gas is discharged outside the mist nozzle 10. At this time, a negative pressure is generated in the liquid existing in the liquid discharge portion 140, and the liquid is also sucked out and discharged together with the gas discharged outside the mist nozzle 10. Incidentally, at this time, by supplying the liquid by pressurization, the spray amount can also be increased. Also, the fineness of the mist to be sprayed can be adjusted according to the outer diameter (Φ) D1, inner diameter (Φ) D2 of the liquid discharge port 144, and the positional relationship of the ejection hole portion 182. In this way, the mist nozzle 10 of the present embodiment can stably generate fine mist even at low pressure and low air volume while simplifying the structure.

[0031] According to the mist nozzle 10 having the above configuration, since the cap 180 can be detachably attached to the nozzle body 100, according to the application and the desired mist generation amount (injection amount), a cap having a different diameter (diameter) of the injection hole portion 182 can be replaced on the mist nozzle body 100, so that the mist generation amount can be more easily adjusted.

[0032] Hereinafter, the mist nozzle 10 of the present embodiment will be described in detail.

[0033] The liquid discharge portion 140 constituting the nozzle body 100 has a hollow portion 142, a liquid discharge port 144 on one end side (liquid downstream side), and a liquid inlet 146 on the other end side (liquid upstream side). The liquid discharge portion 140 may be made of metal, alloy, resin, or ceramic, or may be made of other materials. Considering durability and cost, the liquid discharge portion 140 is preferably made of metal or alloy, particularly stainless steel.

[0034] The outer diameter (Φ) D1 of the liquid discharge port 144 is preferably 0.2 mm or more and 1.0 mm or less. A more preferable outer diameter (Φ) D1 is 0.4 mm or more and 0.9 mm or less, and a particularly preferable outer diameter (Φ) D1 is 0.5 mm or more and 0.8 mm or less. In the present embodiment, the outer diameter (Φ) D1 is 0.5 mm. Also, the inner diameter (Φ) D2 of the liquid discharge port 144 is preferably 0.1 mm or more and 0.9 mm or less. A more preferable inner diameter (Φ) D2 is 0.2 mm or more and 0.8 mm or less, and a particularly preferable inner diameter (Φ) D2 is 0.4 mm or more and 0.7 mm or less. In the present embodiment, the inner diameter of the liquid discharge port 144 is 0.4 mm. Also, the thickness of the liquid discharge part 140 in the liquid discharge port 144 is preferably 0.01 mm or more and 0.2 mm or less, and more preferably 0.05 mm or more and 0.1 mm or less. In the present embodiment, it is 0.05 mm. The outer diameter (Φ) D3 of the liquid inlet 146 is preferably substantially equal to the outer diameter (Φ) D1, and the inner diameter (Φ) D4 of the liquid inlet 146 is preferably substantially equal to the inner diameter (Φ) D2. Note that the sizes of the outer diameter (Φ) D1, inner diameter (Φ) D2, outer diameter (Φ) D3, and inner diameter (Φ) D4 can be appropriately selected according to the gas flow rate and the gas supply pressure.

[0035] Also, a connection port 120a is provided on one end side (liquid downstream side) of the liquid supply path 120 provided inside the holding part 150 constituting the nozzle body 100, and a liquid supply port 120b is provided on the other end side (liquid upstream side). Note that the holding part 150 may be made of metal, alloy, resin, or ceramic, or may be made of other materials. Considering costs and the like, the holding part 150 is preferably made of resin. The liquid supply path 120 is connected to the liquid discharge part 140 via the connection port 120a. In the present embodiment, a concave space part 152 is provided at the tip part on the liquid downstream side of the holding part 150, and the other end side of the liquid discharge part 140 is inserted into the liquid supply path 120 via the space part 152 and the connection port 120a. When the mist nozzle 10 is in use, the space portion 152 is substantially the same as the shape of the liquid discharge portion 140 so that the liquid discharge portion 140 does not fall off from the holding portion 150. Further, the diameter of the connection port 120a is equal to or greater than the outer diameter (Φ) D3 of the liquid inlet 146 so that the other end side of the liquid discharge portion 140 can be inserted into the liquid supply passage 120. Also, the liquid supply port 120b is connected via a pipe or the like to a liquid supply source (not shown).

[0036] Then, the liquid supplied from the liquid supply source flows into the liquid supply passage 120 from the liquid supply port 120b, passes through the liquid supply passage 120, flows into the hollow portion 142 from the liquid inlet 146 of the liquid discharge portion 140, and is discharged from the liquid discharge port 144 through the hollow portion 142. Note that the mist nozzle 10 may be a self-priming type so that it can supply liquid from the liquid supply source, or may be configured to supply liquid using a pump or the like.

[0037] Note that the method (form) of connecting the liquid supply passage 120 to the other end side of the liquid discharge portion 140 is not limited to the above. For example, a method in which the connection port 120a of the liquid supply passage 120 is made convex and is fitted inside one end side of the liquid discharge portion 140 through the liquid inlet 146, a method of connecting both through a connecting member (not shown), and further, a method of integrally forming the liquid discharge portion 140 and the holding portion 150 using a 3D printer or the like can be employed.

[0038] Also, a gas discharge port 162 is provided at one end of the gas supply passage 160, and a gas supply port 164 is provided at the other end. The gas supply port 164 is connected via a pipe and a compression adjustment valve or the like to a gas supply source (not shown). Then, the gas supplied by pressurization from the gas supply source flows into the gas supply passage 160 from the gas supply port 164 and is discharged from the gas discharge port 162 through the gas supply passage 160. Also, gas is ejected from the gas ejection portion 166 through the gas discharge port 162. Here, the gas ejection portion 166 opens in the same direction or substantially the same direction as the opening direction of the liquid discharge port 144. With such a configuration, the gas can be sent to the injection hole portion 182 more efficiently. As the gas supply source, a compressor device is preferably used. The gas supply pressure of the compressor device can be, for example, 0.1 MPa or more and 1 MPa or less, and can also be 0.2 MPa or more and 0.9 MPa or less, 0.3 MPa or more and 0.7 MPa or less, or 0.2 MPa or more and 0.3 MPa or less.

[0039] The cap 180 is cylindrical and is fitted to the tip side (liquid / gas downstream side) of the nozzle body 100. However, the shape of the cap 180 is not limited to this, and any shape may be used as long as it can be detachably attached to the nozzle body 100. Also, as a method of attaching the cap 180 to the nozzle body 100, there are methods such as inserting and fitting the tip side of the nozzle body 100 into the cap 180, providing a fitting groove on one side and a convex portion corresponding to the fitting groove on the other side, and fitting the convex portion into the fitting groove, but it is not limited to this.

[0040] The diameter (Φ) D5 of the axial outer end portion E1 of the injection hole portion 182 is preferably 0.3 mm or more and 1.1 mm or less. A more preferable diameter (Φ) D5 is 0.5 mm or more and 1.0 mm or less, and a particularly preferable diameter (Φ) D5 is 0.6 mm or more and 0.9 mm or less. Also, the diameter (Φ) D6 of the axial inner end portion E2 of the injection hole portion 182 is preferably 0.3 mm or more and 1.1 mm or less. A more preferable diameter (Φ) D6 is 0.5 mm or more and 1.0 mm or less, and a particularly preferable diameter (Φ) D6 is 0.6 mm or more and 0.9 mm or less. The diameter (Φ) D5 and the diameter (Φ) D6 are preferably equal. In this embodiment, the diameter (Φ) D5 and the diameter (Φ) D6 are 0.8 mm. Note that the sizes of the diameter (Φ) D5 and the diameter (Φ) D6 can be appropriately selected according to the gas flow rate and the gas supply pressure.

[0041] Also, in this state, the liquid discharge portion 140 will be at a predetermined position in the X-axis direction and the Y-axis direction. In the mist nozzle 10 of the present embodiment, the liquid discharge port 144 is concentric with the ejection hole portion 182. In this specification, being concentric means that the center point in the radial cross-section of the liquid discharge port 144 and the center point in the radial cross-section of the axial outer end portion E1 of the ejection hole portion 182 are 0.01 mm or less in Φ. Further, the liquid discharge port 144 is located on the liquid upstream side of the axial outer end portion E1 of the injection hole portion 182 and on the liquid downstream side of the axial inner end portion E2 of the ejection hole portion 182. That is, the liquid discharge port 144 is in a state of being inserted through the injection hole portion 182. At this time, the differential pressure generated on the gas upstream side and the gas downstream side of the injection hole portion 182 (near the liquid discharge port 144) becomes larger, and the gas flow velocity on the gas downstream side of the injection hole portion 182 further increases. Thus, since the mist nozzle 10 can efficiently make the liquid downstream region of the liquid discharge port 144 into a negative pressure, the liquid can be discharged from the liquid discharge port 144 with a low-pressure and low-airflow gas supply. In addition, since the gas flow velocity in the gas downstream region of the injection hole portion 182 can be made larger, the gas-liquid mixture can be efficiently and the liquid can be atomized more finely and ejected from the injection hole portion 182. Note that the position of the liquid discharge port 144 in the Y-axis direction is preferably adjusted within a range on the liquid upstream side of the axial outer end portion E1 of the injection hole portion 182 and where the radial cross-section is in the same straight line as the axial inner end portion E2 of the ejection hole portion 182.

[0042] In the present embodiment, the outer diameter (Φ) D1 of the liquid discharge port 144 and the diameter (Φ) D6 of the injection hole portion 182 are preferably such that the diameter (Φ) D6 - outer diameter (Φ) D1 (that is, the distance L between the outer peripheral portion of the liquid discharge port 144 and the inner peripheral surface of the injection hole portion 182) is 0.5 mm or less, and more preferably 0.1 mm or more and 0.15 mm or less. Note that the distance between the outer peripheral portion of the liquid discharge port 144 and the inner peripheral surface of the injection hole portion 182 can be appropriately selected according to the gas flow rate and the gas supply pressure.

[0043] In addition, since the cap 180 is detachably attached to the nozzle body 100, a plurality of caps 180 having spray hole portions with different opening diameters may be prepared, and the cap 180 attached to the nozzle body 100 may be changed according to the gas flow rate and the gas supply pressure.

[0044] Next, the mist nozzle 11, which is a modified example of the present embodiment, will be described with reference to FIG. 6. In the mist nozzle 11, in a state where the cap 180 is attached to the nozzle body 100, the liquid discharge port 144 is on the liquid upstream side of the axial outer end portion E1 of the injection hole portion 182 and is positioned such that its radial cross section and the radial cross section of the axial inner end portion E2 of the ejection hole portion 182 are on the same line. At this time, the gas flow path cross-sectional area at the peripheral edge of the gas discharge port 144 is about 1 / 73 or less of the maximum gas flow path cross-sectional area of the space portion 170. Therefore, the differential pressure generated between the gas upstream side and the gas downstream side of the injection hole portion 182 (near the liquid discharge port 144) becomes larger, and the gas flow velocity on the gas downstream side of the injection hole portion 182 further increases. In this way, since the mist nozzle 11 can efficiently make the liquid downstream region of the liquid discharge port 144 negative pressure, the liquid can be discharged from the liquid discharge port 144 with a low-pressure and low-air volume gas supply. Further, since the gas flow velocity in the gas downstream region of the injection hole portion 182 can be made larger, the mixture of gas and liquid can be efficiently and the liquid can be atomized more finely and ejected from the injection hole portion 182.

[0045] Furthermore, the mist nozzle 12, which is another modified example of the present embodiment, will be described with reference to FIG. 7. In the mist nozzle 12, in a state where the cap 180 is attached to the nozzle body 100, the liquid discharge port 144 is located on the gas upstream side of the axial outer end portion E1 and the axial inner end portion E2 of the injection hole portion 182. At this time, a gas flow region toward the ejection hole portion 182 is generated between the peripheral portion of the liquid discharge port 144 and the axially inner end portion E2 (peripheral end portion) of the injection hole portion 182. Therefore, gas easily flows into the injection hole portion 182, that is, the gas flow velocity easily increases, and a differential pressure easily occurs between the upstream side and the downstream side of the gas near the liquid discharge port 144. As a result, the liquid downstream region of the liquid discharge port 144 can be efficiently made into a negative pressure, so that the mist nozzle 12 can discharge the liquid from the liquid discharge port 144 with a low-pressure and low-air volume gas supply. In addition, since the gas flow velocity in the gas downstream region of the injection hole portion 182 can be made larger, the mixture of gas and liquid can be efficiently ejected from the injection hole portion 182 with the liquid being more atomized.

[0046] Next, the mist nozzle 20 according to another embodiment will be described with reference to FIGS. 8 and 9. The mist nozzle 20 according to another embodiment includes a liquid supply passage 220 that supplies water, which is a mist nozzle that atomizes and ejects water (liquid) with air (gas), a metal injection portion 240 that is detachably provided at the tip portion 220a of the liquid supply passage 220 and ejects water, a gas supply passage 260 that is provided in the nozzle body 200 and supplies and ejects air in the same direction as the ejection direction of water by the injection portion 240 (arrow A direction in FIG. 8), and a resin cap 280 (shown by a two-dot chain line in FIG. 8) in which an ejection hole portion 282 for ejecting mist generated by mixing the air ejected from the gas supply passage 260 and the water ejected from the injection portion 240 is formed, and is detachably attached to the nozzle body 200 so as to surround the gas supply passage 260 and the injection portion 240. When the cap 280 is attached to the nozzle body 200, the injection portion 240 is configured to be located inside the cap 280 without being exposed outside the cap 280.

[0047] Now, the nozzle body 200 is formed of synthetic resin. The nozzle body 200 is provided with a liquid supply passage 220 and a gas supply passage 260 in order to pulverize water into a mist by mixing two fluids of water and low-pressure air at its tip portion.

[0048] The liquid supply path 220 is formed of synthetic resin including the portion protruding from the nozzle body 200, and has a function of a guide path for supplying water toward the tip portion 220a side.

[0049] The injection part 240 is made of a metal material such as brass or stainless steel, and injects water from the liquid supply path 220. The inner diameter (φ1) of its foremost end is 0.2 mm, but it is not limited to this inner diameter and can be changed as appropriate.

[0050] The gas supply path 260 is formed of synthetic resin, and has a function of a guide path for supplying air toward the tip portion 260a side.

[0051] The cap 280 is made of synthetic resin. When it is attached to the nozzle body 200, an ejection hole portion 182 with an inner diameter (φ2) of 0.7 mm to 1.2 mm is formed on the extension line in the longitudinal direction of the injection part 240 (horizontal direction in FIG. 8). Note that the inner diameter of the ejection hole portion 282 can be adjusted as appropriate. By appropriately adjusting this inner diameter, the diameter of the ejected mist can be adjusted. Further, when the cap 280 is attached to the nozzle body 200, the injection part 240 is positioned inside the cap 280 and is in a sealed state except for the ejection hole portion 282 (see FIG. 9).

[0052] Regarding the above configuration, its operation will be described.

[0053] When air is supplied to the tip portion 260a side through the gas supply path 260, a low-pressure state is formed inside the cap 280. Here, when water is supplied toward the tip portion 220a side through the liquid supply path 220, the low-pressure air pulverizes the water. As a result, the water becomes mist-shaped, for example, with a diameter of 5 μm.

[0054] Thus, the water that has become mist is ejected from the ejection hole portion 282 to the outside of the cap 280.

[0055] Incidentally, the amount and diameter of the mist to be generated can be easily adjusted by adjusting the cap 280 or changing the inner diameter of the liquid supply passage 220.

[0056] According to the above-described other embodiments, when the cap 280 is attached to the nozzle body 200, the injection portion 240 is positioned inside the cap 280 without being exposed outside the cap 280 to form a substantially sealed state. Therefore, compared with a conventional mist nozzle in which the injection portion protrudes or is exposed from the cap, even at low pressure and low air volume, a high water supply capacity and the generation of stable fine mist (5 μm to 20 μm) can be realized.

[0057] Also, according to the above-described other embodiments, only the injection portion 240 to which a load is applied is made of metal, and the others are formed of synthetic resin, so it is also superior in terms of durability and light weight.

[0058] Furthermore, according to the above-described other embodiments, since the structure is simple and compact, it is easy to manufacture, and it has excellent effects in terms of practicality, productivity, and economy.

[0059] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof, of course.

Explanation of Reference Numerals

[0060] 10, 11, 12, 20... Mist nozzle 100, 200... Nozzle body 120, 220... Liquid supply passage 140... Liquid discharge portion 240... Injection portion 160, 260... Gas supply passage 180, 280... Cap 182, 282... Jet hole portion

Claims

1. a nozzle body having a cylindrical liquid ejection section with a liquid ejection port on one end side and a holding section connected to the other end side of the liquid ejection section; and a cap having an ejection hole section penetrating an outer surface section and an inner surface section and removably attached to the nozzle body, the holding portion has a liquid supply path connected to the other end side of the liquid ejection portion to supply liquid to the liquid ejection portion, a gas ejection port from which gas is ejected, and a gas supply path that supplies gas to the gas ejection port, When the cap is attached to the nozzle body, a gas ejection part communicating with the gas discharge port, and a space part surrounded by an inner surface part of the cap and the nozzle body and communicating with the ejection hole part and the gas ejection part, the liquid discharge port is located concentrically with the ejection hole portion and between an axial outer end portion and an axial inner end portion of the ejection hole portion, the gas discharge port is located on the other end side of the liquid discharge portion with respect to a position where the liquid discharge port is present, A mist nozzle configured so that a mixture of the liquid discharged from the liquid discharge port and the gas ejected from the gas ejection portion is ejected from the ejection hole portion.

2. The mist nozzle according to claim 1 , wherein the liquid discharge portion is made of a metal or an alloy.

3. 3. The mist nozzle according to claim 1, wherein the liquid ejection port has an outer diameter (Φ) of 0.2 mm or more and 1.0 mm or less, and an inner diameter (Φ) of 0.1 mm or more and 0.9 mm or less.

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