JP6494090B2 - Electrostatic spraying equipment - Google Patents

Description

  The present invention relates to an electrostatic spraying device.

  Conventionally, a polymer that is the material to be applied is made into a solution, and the solution is put into a container with a sharp tip such as a needle tip of a syringe or a thin glass tube, and an electric charge is applied by applying a high voltage. A material in the form of a mist that is charged by the repulsive force of the electric charge is directed to the side called the collector on the ground or the side opposite to the spray side using the Coulomb force, and the material is moved along the collector or the collector. An electrostatic spraying device that collects (stacks) on a substrate to be disposed is known (see Patent Document 1).

When applying paint or the like to an object to be coated with such an electrostatic spraying device, the object is coated on the object side by making the object itself a ground or a collector on the side opposite to the spray side. Can be attracted by electrostatic force.
For this reason, when coating an object to be coated using an electrostatic spraying device, the coating is atomized using a general gas and the atomized liquid is applied to the object to be coated. In comparison, the coating efficiency of the paint can be made extremely high.

JP 2007-277775 A

By the way, in painting using an electrostatic spraying device, for example, when the conditions such as the shape of the object to be coated, the type of paint, the atomization state of the paint, etc. are good, the coating efficiency can be almost 100%. On the other hand, there are cases where the coating efficiency is less than 100%. In this case, there is a problem that the paint that has not been applied to the object to be coated is scattered and the surroundings are soiled.
This invention is made | formed in view of such a situation, and it aims at providing the electrostatic spray apparatus which suppressed that the circumference | surroundings were contaminated with liquids, such as a coating material which does not adhere to a to-be-coated article.

The present invention is grasped by the following composition in order to achieve the above-mentioned object.
(1) The electrostatic spraying apparatus of the present invention is an electrostatic spraying apparatus for applying an atomized liquid atomized by electrostatic explosion to an object to be coated, and has a tip from which a charged liquid is detached, And when the liquid spraying portion is separated by electrostatic force, the collector that collects the atomized liquid that has not been applied to the object to be coated, and the potential of the liquid spraying portion is based on the collector Is the first potential, and when the reference is the object to be coated, the second potential is used, and the polarity direction of the first potential and the polarity direction of the second potential are the same. And at least one voltage applying means for applying a voltage between the liquid spraying part and the collector and between the liquid spraying part and the article to be coated, and the liquid spraying The distance between the part and the collector is the mist on the liquid spray part and the object to be coated. Apart than the distance between the position where the liquid is applied.
(2) In the configuration of (1), the first potential and the second potential are the same potential.
(3) In the configuration of (1) or (2), the collector and the object to be coated are grounded, and the collector and the object to be coated are grounded.
(4) In the configuration of any one of (1) to (3), the liquid spray unit is disposed such that the tip of the liquid spray unit faces the collector, The position where the object to be coated is disposed to apply the atomized liquid is a position deviated from the direction in which the tip of the liquid spraying part faces.
(5) In any one of the constitutions (1) to (4), the booth includes an exhaust port, and exhaust means for exhausting air from the exhaust port. It is provided at the exhaust port.
(6) In the configuration of (5), the collector is detachably attached to the exhaust port.
(7) The atomizing liquid application method of the present invention is an atomizing liquid application method to an object to be coated using the electrostatic spraying device described in any one of the above (1) to (6). In order to apply the atomizing liquid to the object to be coated, from the stage before the object is positioned at a position where the atomizing liquid is applied, the liquid spraying unit and the collector are The liquid is charged and desorbed by the electrostatic force generated by the potential difference therebetween, and the atomized liquid is sprayed.

  ADVANTAGE OF THE INVENTION According to this invention, the electrostatic spraying device which suppressed that the circumference | surroundings are soiled with liquids, such as a coating material which does not adhere to a to-be-coated object, can be provided.

It is a perspective view showing the whole electrostatic spraying device composition of a 1st embodiment concerning the present invention. It is sectional drawing along the central axis of the liquid spraying part of the electrostatic spraying apparatus of 1st Embodiment which concerns on this invention. It is the enlarged view to which the front end side of the liquid spray part of 1st Embodiment which concerns on this invention was expanded, (a) is a figure in case the front end surface of a mandrel is located back, (b) is (a). It is a figure in case the front end surface of a mandrel is located ahead rather than the state of this. It is a figure for demonstrating a state when the electrostatic spraying apparatus of 1st Embodiment which concerns on this invention apply | coats the atomization liquid to the to-be-coated article. It is a perspective view which shows the whole structure of the electrostatic spraying apparatus of 2nd Embodiment which concerns on this invention. It is a perspective view which shows the whole structure of the electrostatic spraying apparatus of 3rd Embodiment which concerns on this invention. It is sectional drawing along the central axis of the liquid spraying part of the electrostatic spraying apparatus of 3rd Embodiment which concerns on this invention. It is a front view of the electrostatic spraying apparatus of 3rd Embodiment which concerns on this invention. It is a perspective view of the collection body of the electrostatic spraying apparatus of 3rd Embodiment which concerns on this invention. It is sectional drawing which shows the modification of the electrostatic spraying apparatus of 1st Embodiment which concerns on this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment.
Unless otherwise specified, expressions such as “front (end)” and “front (direction)” indicate the spray direction side of the liquid in each member, etc., and “rear (end)” or “rear (direction)”. The expression "" represents the opposite side of the liquid spraying direction in each member or the like.

(First embodiment)
FIG. 1 is a perspective view showing the overall configuration of the electrostatic spraying device 10 of the first embodiment.
As shown in FIG. 1, the electrostatic spraying device 10 includes a liquid spraying unit 20 and a collecting body 30, and a liquid such as a paint sprayed from the liquid spraying unit 20 in an atomized liquid state. 40 is an apparatus for applying to 40.
In addition, the electrostatic spraying device 10 includes at least one voltage applying unit (voltage power supply) that applies a voltage between the liquid spraying unit 20 and the collector 30 and between the liquid spraying unit 20 and the object to be coated 40. 50.

  In FIG. 1, the central axis of the liquid spray unit 20 is indicated by one-point oblique lines. As illustrated in FIG. 1, the liquid spray unit 20 has the central axis of the liquid spray unit 20 positioned substantially at the center of the collector 30. The object to be coated 40 is positioned so as to be positioned on the central axis thereof. In this state, a liquid such as paint is applied to the object to be coated 40 in the state of an atomized liquid. Is done.

As can be seen from FIG. 1, the electrostatic spraying device 10 is configured such that the distance between the liquid spraying unit 20 and the collector 30 is such that the atomized liquid is applied to the liquid spraying unit 20 and the workpiece 40. It is made to be separated from the distance to the position.
Moreover, the electrostatic spraying apparatus 10 is provided with the means 60 which earth | grounds the collection body 30 and the to-be-coated object 40, and the collection body 30 and the to-be-coated object 40 are earth | grounded.

Note that the grounding means 60 is not necessarily provided, and whether or not the grounding means 60 is provided is optional. However, when an operator involves an operation of touching the collection body 30 or the object to be coated 40, safety is required. It is preferable to provide from the viewpoint.
Further, in the present embodiment, the case where the electrical wiring from the voltage applying means is directly connected to the object to be coated 40 is shown, but it is not necessary to connect the electrical wiring directly to the object to be coated 40. .

  For example, when the object 40 is transported to a position where the atomized liquid is applied by a transport device or the like, the electrical wiring from the voltage application means is connected to the transport device, The object to be coated 40 may be electrically connected to the voltage applying means via a placement portion on which the object to be coated 40 of the transport device is placed.

(Liquid spray part)
FIG. 2 is a cross-sectional view taken along the one-dotted line (the central axis of the liquid spray unit 20) in FIG.
As shown in FIG. 2, the liquid spraying unit 20 includes a main body 21 made of an insulating material in which a liquid channel 21 b having a liquid supply port 21 a to which a liquid is supplied is formed, and a liquid flow in which the through hole is a main body 21. A liquid nozzle 22 provided at the tip of the main body 21 so as to communicate with the passage 21b, and a mandrel 23 made of a conductive material disposed in the liquid flow path 21b of the main body 21 and in the through hole of the liquid nozzle 22. I have.

The main body portion 21 is provided with a hole portion 21c communicating with the liquid channel 21b in order to take out the mandrel 23 to the rear end side, and a gap between the mandrel 23 is sealed in the hole portion 21c. A seal member 24 is provided to prevent liquid from leaking.
In this embodiment, an O-ring is used as the seal member 24. However, the O-ring is not limited to the O-ring, and any member that can be sealed may be used.

  Further, at the rear end of the mandrel 23 positioned on the rear end side of the main body portion 21 through the hole portion 21c, a knob portion 23a made of an insulating material is provided, and provided so as to penetrate substantially the center of the knob portion 23a. An electrical wiring connection portion 23b made of the conductive material thus provided is provided.

The electrical wiring connecting portion 23b is connected to the electrical wiring from the voltage applying means 50, and the electrical wiring connecting portion 23b is brought into contact with the mandrel 23 so that the mandrel 23 and the electrical wiring connecting portion 23b are electrically connected. Connected.
In the present embodiment, the case where the mandrel 23 is used as the electrode of the liquid spray unit 20 is shown. However, the liquid nozzle 22 is made of a conductive material, and the electrical wiring from the voltage applying means 50 is connected to the liquid nozzle 22. In this manner, the liquid nozzle 22 may be used as the electrode of the liquid spray unit 20.

  A female screw structure 21e for screwing and connecting the knob 23a is provided on the inner peripheral surface of the rear end opening 21d of the main body 21, while a male screw is provided on the outer peripheral surface of the tip of the knob 23a. A structure 23c is provided.

Therefore, the mandrel 23 is detachably attached to the main body portion 21 by screwing the male screw structure 23c on the outer peripheral surface of the tip of the knob portion 23a into the female screw structure 21e of the rear end opening portion 21d of the main body portion 21.
Further, the mandrel 23 can be moved in the front-rear direction by adjusting the screwing amount of the knob 23a, and the position of the distal end surface 23d of the mandrel 23 can be adjusted in the front-rear direction.

In general, the nozzle for spraying the liquid of the electrostatic spraying device is a fine liquid flow path in which the diameter of the through hole through which the liquid flows is small.
This is presumably because a stable liquid atomization state cannot be obtained when the opening diameter of the nozzle tip from which the liquid flows is large.
For example, in general, the opening diameter of the nozzle tip is less than 0.1 mm.

  For this reason, as soon as the liquid dries, the opening at the tip of the nozzle is clogged. However, since the opening diameter is small, there is a problem that it is difficult to eliminate this clogging.

However, the reason will be explained later. However, by using the mandrel 23, it has been found that, compared to the conventional case, it is possible to achieve a good atomization even when the opening diameter of the nozzle tip is a large opening diameter. The opening diameter of the opening 22b at the tip of the liquid nozzle 22 of this embodiment is a large opening diameter of 0.2 mm.
As a result, the frequency of occurrence of clogging can be greatly reduced.

  Note that the opening diameter of the opening 22b of the liquid nozzle 22 is not limited to 0.2 mm. In the embodiment using the mandrel 23, there is no problem even if the opening diameter is about 1 mm.

  The opening diameter of the opening 22b of the liquid nozzle 22 is preferably 0.1 mm or more, more preferably 0.2 mm or more, and more preferably 0, considering that clogging is less likely to occur and cleaning is possible even when clogging occurs. It is preferable to make it larger than 2 mm.

  On the other hand, the opening diameter of the opening 22b of the liquid nozzle 22 is preferably 1.0 mm or less, more preferably 0.8 mm or less, and even more preferably 0.5 mm or less, considering the atomization stability. Is good.

Moreover, in this embodiment, since the mandrel 23 can be moved in the front-rear direction as described above, the clogging can be eliminated by moving the mandrel 23 even if clogging occurs.
Furthermore, since the inner diameter of the through hole of the liquid nozzle 22 is also large enough to allow the mandrel 23 to be disposed, it is possible to remove the mandrel 23 and wash it by flowing a large amount of cleaning liquid.

  FIG. 3 is an enlarged view in which the distal end side of the liquid spraying part 20 is enlarged. FIG. 3A is a case where the distal end surface 23d of the mandrel 23 is located rearward, and FIG. This is a case where the distal end surface 23d of the mandrel 23 is positioned forward of the state (a).

  As shown in FIG. 3 (a), the liquid nozzle 22 has a tapered inner diameter portion (see range A) having a taper angle α that becomes smaller in taper toward the opening portion 22b. 23 has a taper-shaped portion (see range B) having a taper angle β of which the outer diameter decreases toward the distal end surface 23d.

The taper angle α of the tapered inner diameter portion of the liquid nozzle 22 is set larger than the taper angle β of the tapered portion of the mandrel 23.
The diameter of the front end surface 23d of the mandrel 23 is smaller than the diameter of the opening 22b of the liquid nozzle 22, but the diameter of the tapered portion of the mandrel 23 gradually increases toward the rear end side. The liquid nozzle 22 is formed so as to have a portion having a diameter larger than the opening diameter of the opening 22 b of the liquid nozzle 22.

  As described above, by forming the tip side of the liquid nozzle 22 and the mandrel 23, as can be seen by comparing FIGS. 3 (a) and 3 (b), the mandrel 23 is moved in the front-rear direction so that the liquid nozzle 22 The width of the gap formed by the mandrel 23 can be adjusted, and the amount of liquid coming out from the opening 22b of the liquid nozzle 22 can be adjusted.

Further, by moving the mandrel 23 further forward than in the state shown in FIG. 3B, the mandrel 23 abuts on the inner peripheral surface of the liquid nozzle 22 and closes the opening 22 b of the liquid nozzle 22. Is possible.
Therefore, it is possible to prevent the liquid in the liquid nozzle 22 from drying by closing the opening 22b of the liquid nozzle 22 with the mandrel 23 in a state where the liquid is not sprayed, and the liquid nozzle 22 is clogged. This can be suppressed.

(Collector)
The collection body 30 is a member that collects the atomized liquid that has not been applied to the article 40 so that it does not scatter, and attracts and collects the atomized liquid by electrostatic force before the atomized liquid scatters. .

For this reason, as a material of the collector 30, a conductive material or an antistatic material having a surface resistance of 10 ¹⁰ Ω or less is used as a material of the collector 30 so as to form a different electrode with respect to the electrode of the liquid spray unit 20. preferable.

  In the present embodiment, the collector 30 has a flat plate shape as shown in FIG. 1, but the shape itself is not particularly limited because the atomized liquid is collected by electrostatic force as described above. There is no problem even if it has a large number of through openings such as a mesh.

Next, the state when the atomizing liquid is applied to the article to be coated 40 will be described using the electrostatic spraying apparatus 10 of the present embodiment having the above-described configuration.
FIG. 4 is a diagram for explaining a state when the atomizing liquid is applied to the article 40.

  The liquid supplied to the liquid supply port 21 a of the main body 21 is supplied to the tip side of the liquid nozzle 22, and accompanies the voltage applied between the article 40 and the collector 30 and the liquid spraying unit 20. By electrostatic force, it is pulled forward and disengages and atomizes forward.

  In addition, the supply of the liquid only needs to be sequentially supplied with the amount of liquid lost from the liquid spraying part 20 by being consumed by spraying, and the opening 22b of the liquid nozzle 22 (more precisely, the opening 22b and There is no need to pump and supply the liquid at such a pressure that the liquid is ejected from the gap between the mandrel 23. In a state where the liquid is ejected vigorously, it may be impossible to atomize.

  More specifically, FIG. 3 shows that the electrostatic force that pulls the liquid forward balances the adhesion force due to the surface tension and viscosity on the distal end surface 23d of the mandrel 23 and the distal outer peripheral edge 22a of the liquid nozzle 22. Thus, the tailor cone 70 in which the liquid supplied to the tip side of the liquid nozzle 22 has a conical shape at the tip is formed.

The tailor cone 70 is formed into a conical shape by separating positive / negative charges in the liquid by the action of an electric field, and deforming the meniscus at the tip of the liquid nozzle 22 charged with excess charge.
Then, the liquid released from the liquid nozzle 22 is pulled out by the electrostatic force so that the charged liquid is pulled almost straight from the tip of the tailor cone 70 and then spreads upward, downward, left and right obliquely forward by electrostatic explosion. .
The liquid that has been separated to form liquid particles has a drastically increased area in contact with air compared to the state prior to separation, and thus the evaporation of the solvent is promoted, and between the charged electrons as the solvent evaporates. , The electrostatic repulsion (electrostatic explosion) occurs and further breaks up into small liquid particles.

When this splitting occurs, the surface area in contact with air increases compared to before splitting, so that the evaporation of the solvent is promoted, an electrostatic explosion occurs as described above, and a liquid with a small particle size. Split into particles.
The liquid is atomized by repeating such electrostatic explosion.

Here, in the present embodiment, a mandrel 23 is provided in the liquid nozzle 22.
Assuming that the mandrel 23 is not provided as in the conventional electrostatic spraying device, only the tip outer peripheral edge 22 a of the liquid nozzle 22 can be attached to the tip of the liquid nozzle 22.

  When the liquid nozzle 22 having a large opening diameter is employed in such a state, the liquid can be attached only to the outer peripheral edge 22a of the tip of the liquid nozzle 22, so that the liquid can be applied to the top, bottom, left, and right of the liquid nozzle 22, for example. Since the tailor cone 70 cannot easily be formed or the tailor cone 70 itself cannot be maintained, the stability of the liquid particles separated from the liquid nozzle 22 (such as the size, number, and charged state of the particles) It is presumed that the liquid cannot be stably atomized as a result.

On the other hand, in the present invention, the mandrel 23 is disposed in the liquid nozzle 22, and the liquid adheres not only to the outer peripheral edge 22 a of the liquid nozzle 22 but also to the distal end surface 23 d of the mandrel 23.
Therefore, even if the opening diameter of the opening 22b of the liquid nozzle 22 is increased, the tip surface 23d of the mandrel 23 to which the liquid can adhere is present at the center of the opening 22b. The opening diameter of the portion 22b is also considered to make it possible to form a stable tailor cone 70 and to stably atomize the liquid.

  If the front end surface 23d of the mandrel 23 protrudes too far forward from the front outer peripheral edge 22a of the liquid nozzle 22 (that is, the front end surface of the opening 22b of the liquid nozzle 22), the electric field is less likely to act on the liquid exiting the liquid nozzle 22. On the other hand, if the distal end surface 23d of the mandrel 23 is excessively retracted backward from the distal end surface of the opening 22b of the liquid nozzle 22, the state is the same as when there is no portion where the liquid can adhere to the central portion of the opening 22b.

  From this, when applying the atomized liquid, the position of the distal end surface 23d of the mandrel 23 is in the front-rear direction along the central axis of the mandrel 23 with respect to the distal end surface of the opening 22b of the liquid nozzle 22. It is preferably located within 10 times the opening diameter of the opening 22b at the tip of the liquid nozzle 22, more preferably within 5 times, and further preferably within 3 times. Is preferred.

  For example, in this embodiment, since the opening diameter of the opening 22b of the liquid nozzle 22 is 0.2 mm, when applying the atomized liquid, the position of the tip surface 23d of the mandrel 23 is the opening of the liquid nozzle 22. It is preferable that it is located within 2 mm before and after the front end surface of 22b, more preferably within 1 mm, and more preferably within 0.6 mm. Preferably located

  As described above, the position of the distal end surface 23d of the mandrel 23 is determined based on the opening diameter of the opening 22b of the liquid nozzle 22 in accordance with the opening diameter of the opening 22b of the liquid nozzle 22. This is because the size of the liquid coming out of the container is determined.

  For example, when the opening diameter of the opening 22b of the liquid nozzle 22 is less than 0.1 mm as in the prior art, the manufacture of the liquid nozzle 22 is difficult by machining, but as in the present embodiment. In addition, if the opening diameter of the opening 22b of the liquid nozzle 22 can be increased to be 0.1 mm or more, there is an advantage that the liquid nozzle 22 can be manufactured by machining.

  As described above, the liquid leaving the liquid nozzle 22 is sprayed from the liquid nozzle 22 so as to spread diagonally forward, up, down, left and right. Some liquids are directed in the direction offset from the object to be coated 40, but many of these liquids that are directed in the direction offset from the object to be coated 40 can be applied to the object to be coated 40.

That is, even if the liquid is directed in the direction offset from the object to be coated 40, the atomized liquid having a smaller particle diameter due to the electrostatic explosion is charged with the liquid particle, and thus the liquid particle and the object to be coated. Since the electrostatic force generated by the potential difference with the coating 40 is attracted to the coating 40 and applied to the coating 40, many of them can be applied to the coating 40.
However, due to the progress of electrostatic explosion among the liquids that are offset from the object to be coated 40, the mass of the atomized liquid that has a large particle diameter is still large, so that the inertial force is changed to the electrostatic force. There is a case where it is better, and there is a thing that scatters without being applied to the object 40.

  Here, as can be seen from FIG. 4, the positive electrode of the voltage applying means 50 that applies a voltage between the liquid spraying unit 20 and the collector 30 and between the liquid spraying unit 20 and the article to be coated 40 is provided. By connecting to the liquid spraying unit 20 and connecting the negative electrode to the collector 30 and the object to be coated 40, the potential of the liquid spraying unit 20 is set to the first potential when the collector 30 is used as a reference. When the coating is used as a reference, the second potential is set, but the polarity direction of the first potential and the polarity direction of the second potential are made the same, and the second potential is captured. The collecting body 30 is also configured to have a different polarity with respect to the pole of the liquid spraying unit 20.

For this reason, the atomized liquid that has passed through the position of the object to be coated 40 is attracted to the collector 30 by electrostatic force and is applied to the collector 30.
In the present embodiment, since the collector 30 is located at a position far from the position of the object to be coated 40 at a distance from the liquid spraying unit 20, the electrostatic explosion further proceeds and atomizes more than the position of the object to be coated 40. Since the inertial force is reduced and the collector 30 collects the atomized liquid that has not been applied to the object 40 in a state where the inertial force is easily attracted by the electrostatic force, the atomized liquid is efficiently collected. A collection can be performed.

Here, in this embodiment, since the collector 30 and the article to be coated 40 are both grounded by means 60 for grounding the collector 30 and the article to be coated 40, the collector 30 and the article to be coated are grounded. Both potentials of the coating 40 are set to 0 (v).
For this reason, when the collection body 30 is used as a reference, that is, when the potential of the collection body 30 is used as a reference potential, the first potential of the liquid spray unit 20 and the object to be coated 40 are used as a reference. The second potential of the liquid spray unit 20 when the potential of the coating 40 is the reference potential is the same potential.

  As described above, in order to collect the atomized liquid by the collector 30, it is sufficient that the collector 30 has a different polarity with respect to the pole of the liquid spray unit 20. Although it is not necessary for the second potential to be the same, if the same potential is used in this way, it is determined whether the atomized liquid is likely to be applied to the article 40 or the collector 30. It depends on the distance from 20.

  For this reason, the atomized liquid is preferentially applied to the object 40 in a position close to the liquid spraying unit 20, and the mist mainly flies over the zone where the object 40 can be applied as described above. Since the collector 30 collects only the atomizing liquid, the efficiency of applying the atomized liquid to the article 40 can be kept good.

  In other words, if the first potential and the second potential are the same, a part of the atomized liquid that should be attracted to the object 40 side and can be applied, for example, passes through the position of the object 40. The first potential of the liquid spraying portion 20 when a part of the atomized liquid that is applied to the object 40 by electrostatic force is set to the reference potential is the potential of the collector 30. May be attracted to the collector 30 side and may not be applied to the article 40 to be coated.

However, as in the present embodiment, if the first potential and the second potential are the same, the force that attracts the atomized liquid is greater in the collector 30 that is separated from the liquid spray unit 20. It is surely smaller than the object to be coated 40.
For this reason, the collection body 30 collects only the atomized liquid which flew beyond the zone which can be applied to the to-be-coated object 40, and the collection body 30 attracts the atomized liquid which should be able to be applied to the to-be-coated object 40. Thus, it is possible to prevent the application efficiency of the atomized liquid onto the article 40 from being lowered.

  Even if the collector 30 and the object to be coated 40 are grounded and the potentials are not both 0 (v), the first potential and the second potential can be made the same potential. The collector 30 and the object to be coated 40 do not need to be grounded. However, when an operator involves an operation of touching the collector 30 or the object to be coated 40, it is preferable to ground from the viewpoint of safety.

  On the other hand, according to the configuration of the present embodiment, even in the absence of the object to be coated 40, the atomized liquid spray state is generated by the electrostatic force generated by the voltage applied between the collector 30 and the liquid spray unit 20. realizable.

Immediately after the spraying of the atomized liquid is started, the atomization state (liquid spray amount, particle diameter, etc.) may not be stable. Therefore, the mist on the object to be coated 40 in such a state where the atomization state is not stable. Application of the liquefied liquid may cause uneven application.
For this reason, application of the atomized liquid to the article 40 is preferably performed after the atomization state is stabilized, avoiding immediately after the start of spraying.

  However, in the case of a configuration in which the coating object 40 is different from the pole of the liquid spraying unit 20 and the liquid is atomized only by the coating object 40 and the liquid spraying unit 20, the position where the atomized liquid is applied. Since the spraying of the atomized liquid can be started only in a state where the coating object 40 is positioned at the position, application of the atomizing liquid to the coating object 40 immediately after the start of spraying as described above cannot be avoided.

In this respect, in the case of the present embodiment, in order to apply the atomized liquid to the object to be coated 40, the liquid spraying unit 20 and the trap are collected from the stage before the object to be coated 40 is positioned at the position where the atomized liquid is applied. The liquid is charged and desorbed by the electrostatic force generated by the potential difference with the collecting body 30 and the atomized liquid is sprayed. It is possible to implement the atomizing liquid application method in which the atomizing liquid is applied so that the article 40 is positioned at the application position.
Therefore, if it is the electrostatic spraying apparatus 10 of this embodiment, application | coating of the atomization liquid which suppressed the application | coating unevenness of the liquid with respect to the to-be-coated article 40 is realizable.

  In addition, as described above, the electrostatic spraying device 10 of the present embodiment is also applicable to the case where the atomizing liquid is applied to the object to be coated 40 while the object to be coated 40 is automatically and sequentially conveyed by the conveying device. Since the sprayed state can be maintained without 40, continuous coating with little coating unevenness can be performed.

(Second Embodiment)
FIG. 5 is a perspective view showing an overall configuration of an electrostatic spraying apparatus 10 ′ according to the second embodiment of the present invention.
As described with reference to FIG. 1, in the first embodiment, the liquid spraying unit 20 is arranged so that the central axis of the liquid spraying unit 20 is located at the approximate center of the collection body 30, 40 is located on the central axis, and in this state, a liquid such as paint is applied to the article 40 in the form of an atomized liquid.

  That is, the liquid spraying unit 20 is arranged so that the tip of the liquid spraying unit 20 faces the collector 30, and the position where the coating object 40 is disposed to apply the atomized liquid to the coating object 40 is located. This coincides with the direction in which the tip of the liquid spray unit 20 faces.

  On the other hand, in the electrostatic spraying apparatus 10 ′ of the second embodiment, as shown in FIG. 5, the position where the coating object 40 is disposed to apply the atomized liquid to the coating object 40 is the position of the liquid spraying unit 20. The position is deviated from the direction of the tip. This point is different from the first embodiment, and the other points are the same as in the first embodiment.

  As described above, in the electrostatic spraying apparatus 10 ′ in which the position where the coating object 40 is disposed in order to apply the atomized liquid to the coating object 40 is deviated from the direction in which the tip of the liquid spraying unit 20 faces. As shown by arrows in FIG. 5, only the atomized liquid attracted to the object 40 by electrostatic force is applied to the object 40, and the particle diameter is still large due to the progress of electrostatic explosion. Application of the atomized liquid to the object to be coated 40, which has an inertial force that is superior to the drawing force of the object to be coated 40, is avoided.

Therefore, the coating film of the article to be coated 40 is formed only with the atomized liquid having a small particle diameter, and a good coating can be realized in a coating that requires a thin film with a uniform film thickness.
In this case, since the atomized liquid having a large particle size is not positively applied to the article 40, the amount of liquid such as paint that scatters increases, but the scattered liquid is collected by the collector 30. Therefore, the surroundings are not contaminated by a liquid such as a paint that is not applied to the article 40.

(Third embodiment)
FIG. 6 is a perspective view showing the overall configuration of the electrostatic spraying apparatus 10 ″ of the third embodiment according to the present invention (note that the voltage applying means is omitted in FIG. 6), and FIG. It is sectional drawing along the central axis of the liquid spraying part 20 similar to FIG. 2, FIG. 8 is a front view.
As shown in FIGS. 6 to 8, the electrostatic spraying device 10 '' of the third embodiment exhausts air from the booth 80 having the exhaust port 81 and the exhaust port 81 in addition to the configuration of the first embodiment. However, the other points are substantially the same as those of the first embodiment, and the collector 30 is provided at the exhaust port 81.

In addition, in the electrostatic spraying apparatus 10 '' of the third embodiment, the exhaust port 81 and the exhaust unit 83 are connected by the exhaust duct 82. However, the exhaust port 82 is not used and the proximity to the exhaust port 81 is not used. As described above, the air exhaust means 83 may be installed.
As the air exhaust means 83, a general exhaust fan can be used. However, when a liquid such as paint used includes a combustible volatile component, an explosion-proof exhaust fan may be used. .

FIG. 9 is a perspective view showing only the collector 30 of the third embodiment.
As can be seen from FIG. 9, the collector 30 of the third embodiment is formed in a mesh shape so that the air in the booth 80 can be exhausted.

With such a configuration, the atomized liquid that has not been applied to the article 40 is collected at the exhaust port 81 by the air exhaust mechanism including the booth 80 and the air exhaust means 83, and is captured there. Since the collection body 30 is provided, the atomized liquid that has not been applied to the article 40 efficiently gathers near the collection body 30, and the atomization liquid collected near the collection body 30 collects the collection body. Since it is attracted to 30 and collected, it is possible to collect the atomized liquid with extremely high efficiency.
In addition, since the collected atomized liquid adheres to the collection body 30, it is suitable that the collection body 30 is detachably attached to the exhaust port 81 so that it can be periodically replaced.

As mentioned above, although this invention was demonstrated based on specific embodiment, this invention is not limited to the said embodiment, You may implement a deformation | transformation and improvement suitably.
In the above-described embodiment, the case where there is one voltage application unit has been described, but a plurality of voltage application units may be provided.
For example, as in the modification of the first embodiment shown in FIG. 10, voltage application means (voltage power source) 51 that applies a voltage between the collector 30 and the liquid spray unit 20, the article to be coated 40, and the liquid spray You may make it provide the voltage application means (voltage power supply) 52 which applies a voltage between the parts 20. FIG.
In this case, a means 61 for grounding the collector 30 and a means 62 for grounding the article 40 may be provided.

Furthermore, the liquid applied to the article 40 need not be limited to the paint, and the liquid used in the electrostatic spraying device may be selected as necessary.
In addition, from the viewpoint of collecting the atomized liquid, it is not an essential requirement that the liquid spraying unit 20 includes the mandrel 23, and therefore, it is not limited to using the mandrel 23.

  In the above embodiment, the tip surface 23d of the mandrel 23 is a flat plane. However, the tip of the mandrel 23 does not necessarily have to be a flat plane, which contributes to the formation of a stable tailor cone 70. Therefore, for example, the tip of the mandrel 23 may be a curved surface protruding toward the front side like an R shape.

  Thus, the present invention is not limited to a specific embodiment, and modifications and improvements as appropriate are also included in the technical scope of the present invention. Is clear from the description of the scope of claims.

10, 10 ′, 10 ″ electrostatic spraying device 20 liquid spraying part 21 body part 21a liquid supply port 21b liquid channel 21c hole part 21d rear end opening part 22 liquid nozzle 22a front end outer peripheral edge 22b opening part 23 mandrel 23a knob part 23b Electric wiring connection portion 23c Male screw structure 23d End face 24 Seal member 30 Collecting body 40 Coated object 50, 51, 52 Voltage applying means 60, 61, 62 Means for grounding 70 Tailor cone 80 Booth 81 Exhaust port 82 Exhaust duct 83 Exhaust Wind

Claims (6)

An electrostatic spraying device for applying an atomized liquid atomized by electrostatic explosion to an object to be coated,
A liquid spraying portion having a tip from which the charged liquid is detached, and the charging and detachment being performed by electrostatic force;
A collector for collecting the atomized liquid not applied to the object to be coated;
The potential of the liquid spraying portion is a first potential when the collector is used as a reference, and a second potential when the collected object is used as a reference. So that the direction of the polarity of the second and the direction of the polarity of the second potential are the same, and a voltage is applied between the liquid spraying part and the collector and between the liquid spraying part and the object to be coated. And at least one voltage applying means for applying,
The distance between the liquid spray part and the collector is farther than the distance between the liquid spray part and the position where the atomized liquid is applied to the object to be coated ,
The liquid spraying part is arranged so that the tip of the liquid spraying part faces the collector, and a position at which the object to be coated is disposed to apply the atomized liquid to the object to be coated. The electrostatic spraying device is positioned so as not to overlap with the extension line of the central axis of the liquid spraying unit .   The electrostatic spray apparatus according to claim 1, wherein the first potential and the second potential are the same potential. A means for grounding the collector and the object to be coated;
The electrostatic spraying device according to claim 1, wherein the collector and the object to be coated are grounded. A booth having an exhaust port;
An exhaust means for exhausting air from the exhaust port,
The electrostatic spray device according to any one of claims 1 to 3 , wherein the collector is provided at an exhaust port of the booth. The electrostatic spraying device according to claim 4 , wherein the collector is detachably attached to the exhaust port. A method for applying an atomized liquid to an object to be coated using the electrostatic spraying device according to any one of claims 1 to 5 ,
In order to apply the atomizing liquid to the object to be coated, a potential difference between the liquid spraying unit and the collector from the stage before the object to be coated is positioned at a position where the atomizing liquid is applied. The atomizing liquid coating method, wherein the charging and desorption of the liquid are performed by the electrostatic force generated in step 1 and the atomizing liquid is sprayed.

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