JP4997403B2 - Electrostatic spray device nozzle - Google Patents

Description

  The present invention relates to a nozzle of an induction charging type electrostatic spraying device that sprays a chemical solution or the like using static electricity.

  A conventional nozzle of this type of electrostatic spraying device includes a nozzle that ejects a liquid to be sprayed as droplets, and an electrode that is disposed so as to be close to the outside of the diffusion range of the droplet, By applying a high voltage between the liquid supplied to the nozzle and the electrode, the liquid droplets are inductively charged. The electrode is made of an annular metal, and is installed at the tip of an electrode holder formed so as to surround the nozzle. The electrode holder is supported on the proximal end side of the nozzle.

When spraying is started by this nozzle, the chemical liquid ejected from the nozzle adheres to the electrode holder, and a continuous film connected to the electrode and the nozzle is formed. Usually, the main chemical solution contains a spreading agent for facilitating adhesion to crops, insects, etc., so that the continuous film is easily formed. This continuous film may cause a leakage between the electrode and the nozzle. In order to solve these trouble phenomena, there are some which are configured as follows by preventing the trouble film from forming a continuous film in the vicinity of the electrode.
(1) As shown in FIG. 4, the electrode holder 51 of the nozzle hole 50 is formed of a water-repellent material so that even if the droplet D ejected from the nozzle 52 adheres, the electrode holder 51 becomes a water droplet. An embodiment in which the continuous film connected to the electrode 53 is not formed on the electrode 51 (see Patent Document 1).
(2) As shown in FIG. 5, an air discharge port 64 for discharging compressed air is provided in the electrode holder 61 of the nozzle 60, and the droplet D ejected from the nozzle 62 is blown off with the compressed air so as not to adhere. A mode in which a wide continuous film connected to the electrode 63 is prevented from being formed (see Patent Document 2).

JP 2005-125175 A JP 2006-21148 A

  However, since the nozzle hole of the conventional electrostatic spraying device includes a metal electrode, there is a problem that the weight is heavy and the cost is increased. This problem has a great influence on the weight and cost, particularly when a plurality of nozzle holes such as a lily of the valley type are provided.

  Moreover, when the means described in Patent Document 1 or Patent Document 2 is provided in order to prevent the continuous film from being formed, there is a problem that the weight of the nozzle is further increased and the cost is increased. .

The inventor of this application discovered the following fact about the said continuous film through the research regarding the electrostatic spray apparatus for solving the said subject.
(1) After the continuous film is formed at the portion where the electrode is disposed, even if the electrode is not present, the conductive continuous film acts as an electrode. It must be possible to inductively charge.
(2) The time required to form the required continuous film for inductively charging the droplet to the same charge amount as the electrode is determined by the size, shape, material, and surface of the portion where the continuous film is formed. Depending on conditions such as the state and components of the liquid, it must be within tens of seconds at the latest from the start of spraying.

Therefore, the nozzle hole of the electrostatic spray device of the present invention is
A nozzle that ejects liquid to be sprayed into droplets;
It is provided in place of the annular electrode disposed so that the inner periphery is close to the outer periphery of the droplet diffusion range, and is disposed so that the inner periphery is close to the outer periphery of the droplet diffusion range. And an annular portion made of a non-conductive material, formed to allow the surface to be covered with the continuous film of liquid by adhering the droplets during spraying,
A conductor having a conductive surface exposed to be in contact with the continuous film;
Non-conductive, provided in the middle part of the creeping surface from the annular part to the nozzle, and configured to prevent leakage between the annular part and the nozzle by interrupting the continuous film at the middle part A leakage prevention part made of a conductive material,
The annular part is formed so that the surface has affinity for the liquid,
The droplet is induced to be charged by applying a relative high voltage to the liquid supplied to the nozzle to the continuous film through the conductor.

  Here, “the surface is formed so as to allow the surface to be covered with the continuous film of the liquid by adhering the droplet during spraying” is a configuration in which the surface is easily covered with the continuous film. In addition to the aspect in which the surface is provided, an aspect in which the structure for preventing the surface from being covered with the continuous film is not particularly provided is also included.

According to this configuration, the droplet ejected from the nozzle can be induction-charged by using the continuous film without providing an electrode at the nozzle hole. For this reason, the weight of the nozzle hole can be reduced and the cost can be reduced.
In addition, by forming so as to have the affinity, a continuous film can be smoothly formed on the surface of the annular portion, and the time required for inductive charging of droplets by the continuous film can be shortened. Can do.

  According to the nozzle hole of the electrostatic spraying device according to the present invention, there is an excellent effect that the weight can be reduced and the cost can be reduced.

  1 to 3 show a hand-held nozzle portion 1 of an electrostatic spraying device having an injection hole 10 according to an embodiment of the present invention. As shown in FIG. 1, the nozzle portion 1 is arranged in a row with a gap between the grip 2 for an operator to hold, a jet tube 3 projecting from the grip 2, and the tip side of the jet tube 3. And a plurality (five in this example) of nozzle holes 10.

  2 and 3, the nozzle 10 is detachable from the nozzle 11, the nozzle holder 12 that supports the nozzle 11, the joint 13 that connects the nozzle holder 12 to the nozzle 3, and the nozzle holder 12. A nozzle cover 14 that is attached and covers the periphery of the nozzle 11 and a rear cover 15 that is attached to the proximal end side of the nozzle holder 12 are provided.

  The nozzle 11 is configured to eject the liquid to be sprayed supplied as a droplet D through a flow path 16 provided in the interior of the injection tube 3, the joint 13, the nozzle holder 12, and the like. The nozzle 11 may be made of either a non-conductive material or a conductive material. The nozzle 11 of this example is made of resin in order to reduce the weight of the nozzle 10.

  The nozzle cover 14 is made of a nonconductive material and is formed in a substantially cylindrical shape. The peripheral wall of the nozzle cover 14 is provided with a plurality of ventilation windows 14a penetrating inside and outside the peripheral wall. The tip of the nozzle cover 14 is disposed so that the inner periphery is close to the outer periphery of the diffusion range of the droplet D, and the surface is covered with a continuous film S of liquid by the droplet D adhering during spraying. It is the annular part 17 formed so that it might permit. The annular portion 17 of this example is covered with the continuous film S as an aspect “formed to allow the surface to be covered with the liquid continuous film S by the droplet D adhering during spraying”. A configuration that does not particularly impede this is provided. As a preferable aspect of the annular portion 17, an aspect in which the surface is formed so as to have an affinity for a liquid is exemplified. Although it does not specifically limit as this specific aspect, Forming a fine unevenness | corrugation in the surface of the cyclic | annular part 17 or forming the cyclic | annular part 17 with the material which has affinity with a liquid is illustrated.

  A plate-like conductor 18 extending in the length direction (circumferential width direction) of the nozzle cover 14 is disposed on the inner peripheral surface of the nozzle cover 14. The surface of the conductor 18 is a conductive surface exposed so as to be in contact with the continuous film S. A high voltage (relative high voltage with respect to the liquid supplied to the nozzle 11) generated by a high voltage generator (not shown) built in the grip 2 is applied to the conductor 18 by the high voltage lead 4 and the contact shaft 5. It is adapted to be applied via. As a method of providing the conductor 18, in addition to the mode of attaching to the nozzle cover 14 as in this example, the lead 18 made of conductive resin is integrally formed on the nozzle cover 14 or inserted into the nozzle cover 14 of non-conductive resin. This is an example.

  The nozzle holder 12 is made of a non-conductive material and includes a cylindrical holder body 20. At the front end side of the holder main body 20, an intermediate cylindrical portion 21 formed with a smaller diameter than the main body and a small cylindrical portion 22 formed with a smaller diameter than the intermediate cylindrical portion 21 are integrally formed. The nozzle 11 is attached to the distal end side of the small cylindrical portion 22. An annular recess 23 formed between the small cylindrical portion 22 and the middle cylindrical portion 21 is provided in the middle portion of the creeping surface from the annular portion 17 to the nozzle 11 of the nozzle cover 14, and the continuous film S is interrupted at the middle portion. Thus, the leakage prevention portion made of a non-conductive material is configured to prevent leakage between the annular portion 17 and the nozzle 11. A joint 13 is inserted into the opening on the proximal end side of the holder body 20.

  The rear cover 15 is made of a non-conductive material, and an annular disk part 25 attached to the joint 13 and a cylindrical part 26 protruding from the outer periphery of the annular disk part 25 toward the tip of the nozzle 11 are integrally formed. It has been done. The rear cover 15 is disposed so as to cover the base end side of the nozzle holder 12 without contacting. An annular recess 27 formed between the base end side of the nozzle holder 12 and the rear cover 15 is provided in the middle part of the creeping surface from the annular part 17 of the nozzle cover 14 to the grip 2, and the continuous film S is formed in the middle part. This is a leakage prevention portion made of a non-conductive material, which is configured to prevent leakage between the annular portion 17 and the grip 2 by interrupting.

  The operation of the nozzle 10 of the present invention will be described. First, when the high voltage is applied to the conductor 18 and spraying is started, the droplet D ejected from the nozzle 11 is sprayed into the nozzle cover 14 as shown in FIG. The continuous film S is formed on the surface of the annular portion 17. Then, when the high voltage is applied to the continuous film S through the conductor 18, the continuous film S acts as a high-voltage side electrode and starts to inductively charge the droplet D ejected from the nozzle 11. Then, as the continuous film S grows, the charge amount of the droplets D increases, and after a short time from the start of spraying (in this example, the liquid is a pesticide containing a spreading agent, about 1 second, the liquid is water In about 4 seconds in some cases, the droplet D is inductively charged to the same charge amount as when the electrode is provided on the annular portion 17.

  According to the nozzle 10 of the electrostatic spraying apparatus of this example configured as described above, the high voltage is applied to the continuous film S via the conductor 18 so that the droplet D is inductively charged. Since it is configured, the liquid droplet D ejected from the nozzle 11 can be induction-charged by using the continuous film S without providing an electrode at the nozzle hole 10. For this reason, the weight of the nozzle 10 can be reduced and the cost can be reduced. In particular, in the case of a lily of the valley type nozzle portion in which a plurality of nozzle holes 10 are arranged on the distal end side of a long nozzle tube as in this example, the operability can be greatly improved by reducing the weight of the nozzle holes 10. it can.

  Further, if the annular portion 17 is formed so that the surface has affinity for the liquid, the continuous film S is smoothly formed on the surface of the annular portion 17, and the droplet D formed by the continuous film S is formed. The time until the induction charging starts can be shortened.

In addition, this invention is not limited to the said embodiment, For example, it can also be suitably changed and embodied as follows, for example in the range which does not deviate from the meaning of invention.
(1) The present invention is applied to the nozzle holes of other forms of nozzles such as a single head.
(2) The present invention is applied to the injection hole supported by the airframe configured to be able to travel in the field.

It is a perspective view which shows the nozzle part of the electrostatic spraying apparatus provided with the nozzle which concerns on one Embodiment which actualized this invention. It is a disassembled perspective view of the same nozzle. It is sectional drawing of the same nozzle hole during spraying. It is sectional drawing which shows the nozzle part of the conventional electrostatic spraying apparatus. It is sectional drawing which shows the nozzle part of another conventional electrostatic spraying apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle part 2 Grip 3 Jet pipe 4 High voltage | pressure lead wire 5 Contact axis | shaft 10 Injection hole 11 Nozzle 12 Nozzle holder 13 Joint 14 Nozzle cover 14a Ventilation window 15 Rear cover 16 Flow path 17 Annular part 18 Conductor 20 Holder body 21 Middle cylindrical part 22 Small cylindrical part 23 Annular recess 25 Annular disk part 26 Cylindrical part 27 Annular recess D Droplet S Continuous film

Claims (1)

A nozzle that ejects liquid to be sprayed into droplets;
It is provided in place of the annular electrode disposed so that the inner periphery is close to the outer periphery of the droplet diffusion range, and is disposed so that the inner periphery is close to the outer periphery of the droplet diffusion range. And an annular portion made of a non-conductive material, formed to allow the surface to be covered with the continuous film of liquid by adhering the droplets during spraying,
A conductor having a conductive surface exposed to be in contact with the continuous film;
Non-conductive, provided in the middle part of the creeping surface from the annular part to the nozzle, and configured to prevent leakage between the annular part and the nozzle by interrupting the continuous film at the middle part A leakage prevention part made of a conductive material,
The annular part is formed so that the surface has affinity for the liquid,
A nozzle of an electrostatic spraying device configured to inductively charge the droplets by applying a relative high voltage to the liquid supplied to the nozzle to the continuous film via the conductor.

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