WO2019221100A1

WO2019221100A1 - Masking jig

Info

Publication number: WO2019221100A1
Application number: PCT/JP2019/019052
Authority: WO
Inventors: 和昭佐藤; 大地川越
Original assignee: アネスト岩田株式会社
Priority date: 2018-05-18
Filing date: 2019-05-14
Publication date: 2019-11-21
Also published as: JP2019198851A

Abstract

Provided is a masking jig which is used in an electrostatic spray device that sprays an atomized liquid onto an coating object by applying a voltage between a liquid spraying part and a heteropolar part. The masking jig comprises a masking body formed of an insulating material and an outer peripheral conductor body formed of a conductor material or a semiconductor material. The masking body is formed to have one or more apertures for defining a coating section on an object to be coated. The outer peripheral conductor body extends in the normal direction of a plane identical to or contiguous with a plane in which the aperture of the masking body exists and is provided outside around the axis passing through the center of gravity of the aperture and is provided closer to the liquid spraying part than the masking body is. The heteropolar part is made to have the same potential direction as an object to be coated relative to the liquid spraying part.

Description

Masking jig

The present invention relates to a masking jig.

Conventionally, liquid such as paint is detached from the liquid spraying part in a charged state by electrostatic force generated by applying a voltage between the liquid spraying part and a different polar part that is different from the liquid spraying part, In an electrostatic spraying apparatus for spraying an atomized liquid onto an object to be coated, a masking jig having a hole with a predetermined shape and pattern is placed in contact with the vicinity of the object to be coated, What forms the thin film corresponding to a hole part in a to-be-coated article is known (refer patent document 1).

The masking jig described in Patent Document 1 includes a masking main body and a masking auxiliary body, and the masking auxiliary body defines an application part of the object to be coated and a non-application part of the object to be coated. Arranged, the masking body is arranged so as to cover the non-application part that is not covered by the masking auxiliary body, the masking auxiliary body is formed using a conductive material, and the masking body uses an insulating material. Is formed.

Japanese Unexamined Patent Publication No. 2016-221433

By the way, when the coating portion of the object to be coated is small, that is, when the opening area of the hole portion of the masking jig is small, only the hole portion of the masking auxiliary body is reduced or the masking auxiliary body is reduced and the hole portion is also reduced. It needs to be small. However, in the former case, most of the coating material adheres (applies) to the masking auxiliary body, so that the waste of the coating material increases. In the latter case, the liquid spraying portion has a different polarity. Since the electric field forming region of the masking auxiliary body becomes smaller, a strong electric field is not sufficiently formed between the liquid spraying part and the liquid atomization may not be performed normally.

Therefore, the present invention has been made in view of the above problems, and provides a masking jig capable of forming an electric field with a liquid spraying portion even when the total opening area of the hole portions for the application portion is small. The purpose is to do.

According to one aspect of the present invention, a liquid is charged in a charged state by an electrostatic force generated by applying a voltage between a liquid spraying portion and a different polarity portion having a different polarity with respect to the liquid spraying portion. A masking jig used in an electrostatic spraying device that is detached from a part and sprays an atomized liquid onto an object to be coated, and is formed of a masking body formed of an insulating material and a conductive material or a semiconductive material. An outer peripheral conductor, and the masking body is formed with one or a plurality of holes for defining a coating portion for applying a liquid in the object to be coated, and the outer peripheral conductor is formed on the masking body. It extends in the normal direction of the plane that coincides with or touches the surface where the hole exists, and is disposed outside the axis passing through the center of gravity of the hole, and is disposed on the liquid spraying portion side of the masking body. And the liquid spray The masking jig to make the different poles of the same potential direction as the object to be coated is provided for.

According to one aspect of the present invention, there is provided an electrostatic spraying device including a liquid spraying unit and a masking jig having the above-described configuration.

It is a perspective view which shows the whole structure of the electrostatic spraying apparatus using the masking jig of embodiment which concerns on this invention. It is a schematic sectional drawing which shows the whole structure of the electrostatic spraying apparatus using the masking jig of embodiment which concerns on this invention. It is sectional drawing which shows the liquid spraying part of an electrostatic spraying apparatus. It is an enlarged view which shows the front end side of a liquid spray part, (a) When the front-end | tip of a mandrel is located back, (b) When the front-end | tip of a mandrel is located ahead. It is the (a) front view and (b) sectional view showing the masking jig of the embodiment concerning the present invention. It is the (a) front view and (b) sectional view showing the masking jig of the modification concerning the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the embodiments of the present specification, the same members are denoted by the same reference numerals throughout. In addition, the terms “front (end)” and “front (direction)” indicate the spray direction side of the liquid in each member, and the terms “rear (end)” and “rear (direction)” The side opposite to the spray direction of the liquid is indicated, and “left” and “right” indicate a case where the rear is viewed from the front.

First, before describing the masking jig 30 according to the embodiment of the present invention, the electrostatic spraying apparatus 10 using the masking jig 30 will be described. FIG. 1 is a perspective view showing an overall configuration of an electrostatic spraying apparatus 10 using a masking jig 30 according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the overall configuration of the electrostatic spraying apparatus 10 using the masking jig 30 according to the embodiment of the present invention.

(Electrostatic spray device)
As shown in FIGS. 1 and 2, the electrostatic spraying device 10 includes a liquid spraying unit 20 having a liquid nozzle 22, a masking jig 30, and a different polar part 40 having a different polarity with respect to the liquid spraying unit 20. A voltage applying means (voltage power source) 50 for applying a voltage between the liquid spraying unit 20 and the liquid spraying unit 20;

In the present embodiment, the case where the electrical wiring from the voltage applying means (voltage power source) 50 is directly connected to the object to be coated and the object itself is used as the heteropolar portion 40 is shown. An electrical wiring from a voltage applying means (voltage power source) 50 is connected to a placement portion (not shown) for placing the coating material, and this placement portion is defined as a different polarity portion 40, and the placement portion is covered with the placement portion. The coating material may be electrically connected to the voltage applying means (voltage power source) 50. Also, the term “different pole” does not only mean the relationship between the so-called positive electrode (positive electrode) and the negative electrode (negative electrode), but the relationship between a high potential and a low potential even if the same polarity is used. Furthermore, it also means a case where an electric field is formed with relatively different polarities.

The object to be coated (hereinafter referred to as “the object to be coated 40”) serving as the different pole portion 40 is grounded by the grounding means 60. The grounding means 60 is not an essential component, but the object to be coated 40 is preferably provided from the viewpoint of safety because the operator may touch it.

(Liquid spray part)
FIG. 3 is a cross-sectional view showing the liquid spray unit 20 of the electrostatic spray device 10. Note that FIG. 3 shows only the liquid spray unit 20 and illustrates a state in which a liquid such as paint is sprayed from the liquid spray unit 20 as will be described later.

As shown in FIG. 3, the liquid spray unit 20 includes a body part 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 having a body part 21 with a through hole. A liquid nozzle 22 provided at the tip of the body portion 21 so as to communicate with the flow path 21b, and a mandrel 23 made of a conductive material disposed in the liquid flow path 21b of the body portion 21 and in the through hole of the liquid nozzle 22. It is equipped with.

The 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.

And the knob 23a which consists of an insulating material is provided in the rear end of the mandrel 23 located in the rear end side of the trunk | drum 21 through the hole 21c, and it penetrates substantially the center of the knob 23a. An electrical wiring connection portion 23b made of the provided conductive material is provided.

As shown in FIG. 1 and FIG. 2, the electrical wiring from the voltage applying means 50 is connected to the electrical wiring connecting portion 23b. As shown in FIG. 3, the mandrel 23 and the electric wiring connection part 23 b are electrically connected by causing the electric wiring connection part 23 b to contact the mandrel 23.

In the present embodiment, the mandrel 23 is used as an electrode on the liquid spraying unit 20 side. However, for example, the liquid nozzle 22 of the liquid spraying unit 20 is made of a conductive material, and the voltage applying unit 50 is connected to the liquid nozzle 22. The liquid nozzle 22 may be used as an electrode on the liquid spraying unit 20 side.

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

That is, the mandrel 23 is detachably attached to the body part 21 by screwing the male thread structure 23c on the outer peripheral surface of the tip of the knob 23a into the female thread structure 21e of the rear end opening 21d of the body part 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.

The opening diameter of the opening 22b at the tip of the liquid nozzle 22 is formed with a large opening diameter of 0.2 mm. The opening diameter of the opening 22b of the liquid nozzle 22 is not limited to 0.2 mm. For example, in the form using the mandrel 23, the opening diameter may be about 1.0 mm, and clogging is less likely to occur, and considering that clogging can be easily performed, cleaning can be easily performed 0.1 mm or more. Is preferably 0.2 mm or more, and more preferably larger than 0.2 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. It is good to do.

FIG. 4 is an enlarged view in which the distal end side of the liquid spraying unit 20 is enlarged. (A) When the distal end surface 23d of the mandrel 23 is located rearward, (b) When the distal end surface 23d of the mandrel 23 is located forward It is.

As shown in FIG. 4 (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 made 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.

Thus, by forming the tip side of the liquid nozzle 22 and the mandrel 23, the width of the gap formed by the liquid nozzle 22 and the mandrel 23 can be adjusted by moving the mandrel 23 in the front-rear direction. The amount of liquid exiting from the opening 22b of the liquid nozzle 22 can be adjusted.

In addition, by moving the mandrel 23 further forward than in the state shown in FIG. 4B, the mandrel 23 contacts 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 such as paint is not sprayed. Clogging can be suppressed.

(Different pole part 40)
In the present embodiment, as described above, the case where the article 40 is used as the different pole portion 40 is shown, and the electric wiring on the opposite side to the one connected to the mandrel 23 of the voltage applying means (voltage power source) 50 is shown. Is connected to the object to be coated 40, so that the object to be coated 40 itself has a different polarity with respect to the liquid spray unit 20.

However, for example, when the object 40 is conveyed to a position where a liquid such as paint is applied by a conveying device or the like, the object 40 of the conveying device carries the electrical wiring from the voltage application means 50. The article to be coated 40 may be electrically connected to the voltage application means 50 through the placement portion so as to be connected to the placement portion to be placed.

Returning to FIG. 3, the state in which the liquid is sprayed from the liquid spraying unit 20 will be described, and then the masking jig 30 for applying the sprayed liquid only to a predetermined range of the article 40 to be coated. Will be described.

The liquid supplied to the liquid supply port 21 a of the body part 21 is further supplied to the tip side of the liquid nozzle 22, and the static electricity accompanying the voltage applied between the article 40 (different pole part 40) and the mandrel 23. By force, it is pulled forward and disengages and atomizes forward.

In addition, the supply of the liquid should just be sequentially supplied with the liquid which is lost from the liquid spraying part 20 by being consumed by spraying, and the opening 22b (more precisely, the opening 22b and the liquid nozzle 22). If the pressure is supplied at such a pressure that the liquid is ejected from the gap between the mandrel 23, the atomization may not be possible.

Then, as shown in FIG. 3, the electrostatic force that pulls the liquid forward balances the adhesion force due to the surface tension and viscosity to the distal end surface 23 d of the mandrel 23 and the outer peripheral edge 22 a of the liquid nozzle 22, The liquid supplied to the tip side of the nozzle 22 forms a Taylor cone TC having a conical shape at the tip.

This Taylor Cone TC is formed in a conical shape by the positive / negative charge separation occurring in the liquid by the action of an electric field, and the meniscus at the tip of the liquid nozzle 22 charged with excess charge is deformed. . Then, the liquid is pulled straight from the tip of the Taylor cone TC by electrostatic force, and then the liquid is sprayed over a wide range by electrostatic explosion.

The liquid to be sprayed, that is, the liquid that has been separated from the liquid nozzle 22 to become liquid particles has a drastically larger area in contact with the air than before the separation, so that the evaporation of the solvent is promoted. As the gas vaporizes, the distance between the charged electrons approaches, electrostatic repulsion (electrostatic explosion) occurs, and further, the liquid particles are divided 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, the mandrel 23 is provided in the liquid nozzle 22, but if the mandrel 23 is not provided, the portion to which the liquid can adhere is only the outer peripheral edge 22 a of the tip of the liquid nozzle 22. .

In this case, when the opening diameter of the opening 22b of the liquid nozzle 22 is increased, the liquid can be attached only to the outer peripheral edge 22a of the front end of the liquid nozzle 22, so that, for example, the liquid may fluctuate vertically and horizontally from the liquid nozzle 22. It is easy to form a beautiful Taylor Cone TC, or the Taylor Cone TC itself cannot be maintained, so that the stability of the liquid particles leaving the liquid nozzle 22 (particle size, number, charged state, etc.) It is inferred that the liquid cannot be stably atomized as a result.

Therefore, in this embodiment, the mandrel 23 is arranged 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 large, the tip end surface 23d of the mandrel 23 to which the liquid can adhere is present at the center of the opening 22b, so that a stable Taylor cone TC can be formed. It is thought that stable atomization of the liquid can be achieved.

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, the position of the distal end surface 23d of the mandrel 23 is the liquid nozzle in the front-rear direction along the central axis of the mandrel 23 with the liquid spraying state as a reference with respect to the distal end surface of the opening 22b of the liquid nozzle 22. It is suitable that it is located within 10 times the opening diameter of the opening 22b at the tip of 22, more preferably located within 5 times, more preferably located within 3 times. It is.

For example, in this embodiment, when the opening diameter of the opening 22b of the liquid nozzle 22 is 0.2 mm and the electrostatic force is not taken into consideration, the liquid exiting from the opening 22b of the liquid nozzle 22 is at the tip of the liquid nozzle 22. It comes out to be a hemisphere with a diameter of about 0.2 mm.

The tip of the mandrel 23 is present near the liquid so that a conical Taylor cone TC can be formed by the action of an electric field (electrostatic force) on the liquid coming out of the tip of the liquid nozzle 22. Good. Therefore, it is preferable that the front end surface of the opening portion 22b of the liquid nozzle 22 is located within 2 mm forward (in the direction of exit), while the tip of the mandrel 23 is liquid so as to affect the adhesion of the liquid. It is preferable that the nozzle 22 is located within 2 mm backward (in the retracting direction) from the front end surface of the opening 22b.

Thus, by providing the mandrel 23, the opening diameter of the opening 22b of the liquid nozzle 22 can be made large so that clogging can be suppressed. Moreover, since the opening diameter of the opening part 22b of the liquid nozzle 22 can be enlarged, the liquid nozzle 22 can be manufactured by machining.

In the present embodiment, the tip of the mandrel 23 is shown as a flat plane as the tip surface 23d. However, the tip of the mandrel 23 is not necessarily a flat flat surface, and the stable cone TC Since it only has to contribute to the formation, for example, the tip of the mandrel 23 may be a curved surface protruding toward the front side, like an R shape.

In this way, the liquid sprayed from the liquid spraying unit 20 (liquid nozzle 22) becomes an atomized liquid while repeating electrostatic explosion, and the atomized liquid is in a charged state. It is attracted to the 40 (different pole part 40) side by electrostatic force and applied to the article 40.

(Masking jig)
The masking jig 30 will be described with reference to FIGS. 1, 2, and 5. FIG. 5A is a front view and FIG. 5B is a cross-sectional view showing a masking jig 30 according to an embodiment of the present invention.
The masking jig 30 includes at least a masking main body 31 disposed on the workpiece 40 side and an outer peripheral conductor 32 disposed on the liquid spraying unit 20 side. The masking main body 31 and the outer peripheral conductor 32 are formed separately from each other, and the outer peripheral conductor 32 is detachably or detachably attached to the masking main body 31.

The masking body 31 is formed in a substantially rectangular flat plate shape (so as to extend in a plane), but the external dimensions and shape of the masking body 31 are arbitrary as long as the object to be coated 40 can be covered, For example, the outer shape may be formed in a curved shape according to the shape of the article to be coated 40, or may be formed in a concave or convex stepped shape.

The masking body 31 is charged in the same potential direction as the liquid sprayed on the surface by the electrostatic force generated by the voltage applied between the object to be coated 40 and the liquid spraying part 20 (that is, the liquid is charged to a positive charge). If so, the surface is charged with a positive charge, and if the liquid is charged with a negative charge, the surface is charged with a negative charge) (for example, 0.5 mm or more, preferably 1). 0.0 mm or more). However, the thickness of the masking main body 31 may not be uniform.

If the thickness of the masking body 31 is increased to facilitate polarization, the masking body 31 is likely to be in a favorable charged state that repels charged liquid and prevents liquid from being applied onto the masking body 31. Or it can be reduced.

Further, the masking body 31 is formed using an insulating material such as polyethylene, polypropylene, polyphenylene sulfide, polyethylene terephthalate, or fluorine resin, but it is more preferable if it has excellent solvent resistance.

Furthermore, the masking main body 31 has a hole 31a that defines a coating part 41 for applying a liquid in the article to be coated 40 and a non-coating part 42 for not applying a liquid in the article to be coated 40 at the approximate center.

The hole 31a is formed of one or a plurality of holes having an arbitrary shape such as a circle, a triangle, or a polygon according to the shape of the desired application portion 41. The hole 31a according to the present embodiment. Is a single circular hole with the axis CL as the center of gravity (center). However, the center of gravity of the hole 31a is the center of mass when the mass is uniformly distributed within the outline of the hole 31a. Further, when the hole portion 31a is formed by a plurality of holes, the axis CL passes through the center of gravity of the plurality of holes.

At this time, the maximum radius from the center of gravity of the hole 31a may be 4 mm or less, and a diameter of about 4 mm to 5 mm is particularly preferable. In other words, the sum total of the opening areas of the holes 31a is preferably, for example, 50 mm ² or less. Note that the axis CL in the masking jig 30 of the embodiment extends in the normal direction of the plane that coincides with the plane on which the hole 31a exists, and further in the normal direction of the plane in which the masking body 31 extends. Is also extended. On the other hand, when the hole 31a is formed in the curved masking body 31, the axis CL extends in the normal direction of the plane that is in contact with the curved surface where the hole 31a exists at the position of the center of gravity of the hole 31a (or If the sum of the opening areas of the holes 31a is within the above range, the holes 31a can be regarded as being substantially in a plane, so that the opening area of the holes 31a is also expanded into a flat surface. (It may be determined that it exists on a plane without being determined.)

On the other hand, the peripheral conductor 32 is made of a conductive material or a semiconductive material so that a strong electric field is formed between the object 40 and the liquid spray unit 20 by the voltage applied between the object 40 and the liquid spray unit 20. It is formed using a property material. As the conductive material for forming the outer peripheral conductor 32, a metal such as copper or aluminum is preferable, and metal foil is particularly preferable from the viewpoint of ease of handling such as moldability and weight. As the semiconductive material, carbon or metal is used. A resin in which the conductive material is blended is preferable. The outer peripheral conductor 32 is connected to the grounding means 60 (or the pole on the side opposite to the liquid spraying part 20 in the voltage applying means 50).

The outer peripheral conductor 32 is formed in a circular ring shape having a circular opening 32a that allows passage of the sprayed liquid. The opening 32a has a sufficiently larger inner diameter than the hole 31a of the masking main body 31, and the center thereof is set at a position that is concentric with the center of the hole 31a. That is, the outer peripheral conductor 32 is disposed outside the hole 31a around the axis CL passing through the center of gravity (center) of the hole 31a, and has a shape that is rotationally symmetric with respect to the axis CL. In the outer peripheral conductor 32 of this embodiment, the inner diameter is 20 mm and the outer diameter is 30 mm.

In other words, the outer peripheral conductor 32 is disposed outside the application range in which the liquid is applied when the liquid spraying unit 20 is placed 10 cm away from the article 40 (that is, the application) Not placed inside the range.) This is because when the inner diameter of the outer peripheral conductor 32 is small and the inner periphery of the outer peripheral conductor 32 becomes too close to the axis CL, the atomized liquid becomes more attracted to the outer peripheral conductor 32, and the article 40 This is because the amount of liquid adhering to the surface is reduced, and the outer peripheral conductor 32 is preferably disposed at a position not included in the application range.

This application range varies depending on the viscosity of the liquid, but is usually about 10 mm in maximum diameter (80 mm ^{2 in the} case of an area), and the opening 32 a of the outer peripheral conductor 32 is matched to the liquid actually used. The inner diameter should be designed.

By disposing the outer peripheral conductor 32 between the liquid spraying part 20 and the masking main body 31 in this way, the different polar part 40 (application part 41 of the object to be coated 40) is small and the masking main body 31 is liquid sprayed. Even if charged by the unit 20, the outer conductor 32 is different from the liquid spray unit 20 in the same potential direction as the workpiece 40 (for example, the outer conductor 32 and the workpiece 40 have the same potential) and Therefore, a strong electric field can be formed between the liquid spraying part 20 and the outer peripheral conductor 32 to enable electrostatic atomization. The potential difference between the liquid spraying unit 20 and the outer peripheral conductor 32 may be in a range that can be atomized. However, since the outer peripheral conductor 32 is arranged close to the object to be coated 40, Preferably, it is the same potential as 40 or in a range that does not cause a problem in discharge.

And the liquid sprayed on the masking body 31 (front) from the hole 31a avoids the charged masking body 31 and gathers in the hole 31a, and the sprayed liquid is deposited on the workpiece 40. It will be applied.

Incidentally, the masking jig 30 of the present embodiment further includes an inner peripheral conductor 33 disposed between the object to be coated 40 and the masking main body 31 in addition to the masking main body 31 and the outer peripheral conductor 32 described above. . The inner peripheral conductor 33 is provided on the surface of the masking body 31 on the object 40 side, and is arranged in a non-contact state with a space from the object 40 to be coated. The inner peripheral conductor 33 is also connected to the ground means 60.

The inner peripheral conductor 33 is made of a conductive material, like the masking body 31. The outer dimension / shape of the inner peripheral conductor 33 is arbitrary as long as it is smaller than the masking main body 31 and larger than the hole 31a. The inner conductor 33 is arranged such that the second hole 33a having a diameter smaller than or equal to the diameter of the hole 31a of the masking main body 31 is concentric with the center of the hole 31a.

That is, the axis CL passes through the center of gravity (center) of the hole 31 a of the masking body 31, the center of gravity (center) of the opening 32 a of the outer peripheral conductor 32, and the center of gravity (center) of the second hole 33 a of the inner peripheral conductor 33. In addition, the axis CL coincides with the central axis of the mandrel 23 of the liquid spraying unit 20.

The second hole 33a is formed of one or a plurality of holes having an arbitrary shape such as a circle, a triangle, or a polygon according to a desired shape of the application portion 41. In the present embodiment, The second hole 33a is a single circular hole and has a similar relationship to the circular hole of the hole 31a, but may have different shapes. At this time, the maximum radius from the center of gravity of the second hole portion 33a may be smaller than or equal to the radius of the hole portion 31a of the masking main body 31, and a diameter of about 1 mm to 2 mm is particularly preferable. That is, the second hole 33a is preferably located on the inner side with respect to the axis CL than the hole 31a. When a plurality of hole portions 31a are formed, the second hole portion 33a is also formed corresponding to each hole portion 31a.

In this way, by disposing the inner peripheral conductor 33 between the object to be coated 40 and the masking main body 31, it is possible to form a different polarity in a larger range than the case of only the object to be coated 40. The collected liquid can be collected on the center side of the hole 31a of the masking body 31. Then, the liquid that has come off the second hole 33a and has reached the inner peripheral conductor 33 (front) has been applied onto the inner peripheral conductor 33, and has also reached the second hole 33a (front). Is applied on the object to be coated 40. Therefore, the boundary 43 between the application part 41 and the non-application part 42 in the article 40 can be made clearer.

However, the inner peripheral conductor 33 may be disposed so as to contact the workpiece 40. In this case, the inner peripheral conductor 33 can be regarded as having the same potential as the object to be coated 40, that is, the inner peripheral conductor 33 can be regarded as a part of the object to be coated 40 in terms of potential.

For this reason, the sprayed liquid is not collected by the center side of the 2nd hole 33a of the inner periphery conductor 33 by electrostatic repulsion, but on the inner periphery conductor 33 remove | deviated from the 2nd hole 33a ( The liquid that has reached the front) is applied onto the inner peripheral conductor 33, and the liquid that has reached the second hole 33 a (front) is applied onto the article 40. Therefore, the liquid that has reached the outside of the second hole 33a while avoiding the masking body 31 is applied to the application part 41 in the vicinity of the boundary 43 of the article 40, and the applied liquid is thicker than the other parts. It is suppressed.

Further, since the liquid is not repelled at the edge of the second hole 33a and the liquid is neatly applied up to the boundary 43, the boundary 43 between the non-application part 42 and the application part 41 is accurately measured. It becomes possible to form well.

As described above, since the liquid is applied to the outer peripheral conductor 32 and the inner peripheral conductor 33, the outer peripheral conductor 32 or the inner peripheral conductor 33 can be removed by setting the outer conductor 32 or the inner peripheral conductor 33 so as to be detachable. It becomes possible to perform washing, and workability can be improved.

From the viewpoint of liquid application, the outer peripheral conductor 32 and the inner peripheral conductor 33 do not have to be detachably attached to the masking body 31. For example, as shown in FIG. 6, the outer peripheral conductor 32 and the masking main body 31 may be integrated so as not to be detachable. Even if it does in this way, compared with the case where a liquid can be applied to the masking jig 30 whole, since only the part of the outer periphery conductor 32 has only to be partially cleaned, the working efficiency can be greatly improved. It becomes possible.

Such a masking jig 30 in which the outer peripheral conductor 32 and the inner peripheral conductor 33 and the masking main body 31 are integrated so as not to be detachable is formed by two-color molding using, for example, a conductive plastic material and an insulating plastic material. Thus, it can be formed. Alternatively, the outer peripheral conductor 32 and the inner peripheral conductor 33 are made of a conductive material, and the outer peripheral conductor 32 and the inner peripheral conductor 33 are subjected to insert molding using an insulating plastic material, etc. You may make it form the masking main body 31 integrated so that attachment or detachment is impossible.

As described above, the masking jig 30 according to the embodiment of the present invention includes the masking body 31 formed of an insulating material and the outer peripheral conductor 32 formed of a conductive material or a semiconductive material. The masking body 31 is provided with a hole 31a that defines the application part 41 of the article 40 to be coated, and the outer peripheral conductor 32 is a plane that coincides with or touches the plane on which the hole 31a of the masking body 31 exists. It is arranged outside the axis CL that extends in the linear direction and passes through the center of gravity of the hole 31a, is arranged on the liquid spraying part 20 side of the masking body 31, and is coated with respect to the liquid spraying part 20. It is made to become the different pole part 40 of the same electric potential direction. Thereby, in the electrostatic spraying apparatus 10, an electric field can be formed between the liquid spraying part 20 and the outer peripheral conductor 32 of the masking jig 30, and the total opening area of the holes 31a through which the liquid passes is small. However, the liquid can be electrostatically atomized.

In addition, the boundary 43 between the application part 41 that applies the liquid of the object to be coated 40 and the non-application part 42 that does not apply the liquid can be accurately formed, and the liquid applied near the boundary 43 of the application part 41 can be formed. It can suppress that thickness becomes thick.

The outer peripheral conductor 32 of the embodiment is at the same potential as the article 40 to be coated. As a result, a strong electric field is formed between the liquid spraying part 20 and the outer peripheral conductor 32 as in the case where a strong electric field capable of electrostatic atomization can be formed between the liquid spraying part 20 and the workpiece 40. can do.

The outer peripheral conductor 32 of the embodiment has a circular ring shape that is rotationally symmetric with respect to the axis CL. As a result, the electric field formed around the axis CL is rotationally symmetric with respect to the axis CL, so that there is no unevenness in the distribution of the electric field in any direction of the object to be coated 40, and uneven coating is generated. Can be suppressed.

In the masking body 31 of the embodiment, the sum total of the opening areas of the holes 31a is 50 mm ² or less. For example, when the opening area of the hole 31a (that is, the application part 41) is large, a strong electric field is sufficiently formed between the hole 40a and the object to be coated 40. Although it can atomize, in the case of the to-be-coated object 40 where the area of the application part 41 is small, if the masking jig 30 of the embodiment is not used, electrostatic atomization cannot be performed, which is particularly effective.

The outer peripheral conductor 32 of the embodiment is arranged outside the application range where the liquid is applied when the liquid spraying part 20 is placed 10 cm away from the object to be coated 40 (not arranged inside the application range). Thereby, even if the outer periphery conductor 32 becomes a different polarity with respect to the liquid spraying part 20, possibility that the atomized liquid will apply to the outer periphery conductor 32 can be made low.

The masking jig 30 according to the embodiment further includes an inner peripheral conductor 33 formed of a conductive material, and the inner peripheral conductor 33 is disposed between the workpiece 40 and the masking main body 31. Moreover, the inner peripheral conductor 33 has a second hole 33a smaller than the hole 31a, and the second hole 33a is located on the inner side with respect to the axis CL than the hole 31a. Thereby, the boundary 43 of the application part 41 and the non-application part 42 can be made clearer.

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.

For example, you may make it provide the additional different pole part 40 which accelerates | stimulates that the liquid is made to detach | leave in the charged state near the liquid nozzle 22 of the liquid spraying part 20.

In the above embodiment, when the coating film is formed, the object to be coated 40 is fixed to the placement portion and is not moved with respect to the masking jig 30, but the placement portion can be moved up and down or left and right. Then, the coating film may be formed while moving the article to be coated 40.

In the above embodiment, the masking main body 31 and the inner peripheral conductor 33 are arranged so as to come into contact with each other, but the masking main body 31 and the inner peripheral conductor 33 are arranged so as to provide an interval in the axial direction of the axis CL. May be. Even if the masking jig 30 is arranged in this way, the boundary 43 between the application part 41 and the non-application part 42 can be made clearer.

In the above embodiment, the outer peripheral conductor 32 is disposed so as to contact the surface of the masking main body 31 on the liquid spray unit 20 side. However, the masking main body 31 and the outer peripheral conductor 32 are spaced apart in the axial direction of the axis CL. You may arrange so that it may provide. That is, it is only necessary to be disposed between the liquid spray unit 20 and the masking body 31 so as to be fixed at a fixed position with respect to the axis CL. Even if the masking jig 30 is arranged in this way, the boundary 43 between the application part 41 and the non-application part 42 can be made clearer.

In the above embodiment, the outer peripheral conductor 32 is formed in a circular ring shape. However, if the outer peripheral conductor 32 is arranged rotationally symmetrically with respect to the axis CL, for example, even if it is a square frame shape, the axis CL is sandwiched therebetween. It may be in the form of a bar arranged in parallel, or like the masking jig 130 shown in FIG. 6, the outer peripheral conductors 132 as projections such as a dome shape or a disk center around the axis CL at equal intervals ( It may be arranged so as to be scattered at the same angle (for example, six places in FIG. 6). Also in FIG. 6, the inner peripheral conductor 33 may be arranged.

From the above-described embodiment, at least the following forms are grasped.
(1) According to one embodiment, the liquid spray is charged in a charged state by an electrostatic force generated by applying a voltage between the liquid spray unit and a different polar part having a different polarity with respect to the liquid spray unit. A masking jig used in an electrostatic spraying device that is detached from a part and sprays an atomized liquid onto an object to be coated, and is formed from a masking body formed of an insulating material and a conductive material or a semiconductive material. An outer peripheral conductor, and the masking body has one or a plurality of holes defining a coating portion for applying a liquid in the object to be coated, and the outer peripheral conductor is formed on the masking body. It extends in the normal direction of the plane that coincides with or touches the plane where the hole exists, and is disposed outside the axis passing through the center of gravity of the hole, and is disposed on the liquid spraying portion side of the masking body. And the liquid spraying part Masking jig so as to be different poles of the same potential direction as the object to be coated is provided with.

(2) In the form of (1), the outer peripheral conductor may be at the same potential as the object to be coated.

(3) In the form of (1) or (2), the outer peripheral conductor may be disposed between the object to be coated and the masking body in the axial direction.

(4) In any one form from the above (1) to (3), the outer peripheral conductor may be rotationally symmetric with respect to the axis.

(5) In any one form from the above (1) to (4), the masking main body may have a total opening area of the holes of 50 mm ² or less.

(6) In any one form from the above (1) to (5), the masking body may be formed of a curved surface curved in the axial direction of the shaft.

(7) In any one form of the above (1) to (6), the masking jig further includes an inner peripheral conductor formed of a conductive material, and the inner peripheral conductor is It may have a 2nd hole of the size below a hole, and the 2nd hole may be located inside the axis rather than the hole.

(8) In the form of (7), the inner peripheral conductor may be disposed between the object to be coated and the masking body in the axial direction.

(9) In the form of (7), the inner peripheral conductor may be disposed so as to come into contact with the object to be coated.

(10) According to one form, an electrostatic spraying device provided with a liquid spraying part and the masking jig of any one form from said (1) to (9) is provided.

According to the above-described embodiment, it is possible to provide a masking jig capable of forming an electric field with the liquid spraying portion even if the total opening area of the hole portions for the application portion is small.

This application claims priority based on Japanese Patent Application No. 2018-096620 filed on May 18, 2018. The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2018-096620 filed on May 18, 2018 is incorporated herein by reference in its entirety.

The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Laid-Open No. 2016-212433 is incorporated herein by reference in its entirety.

DESCRIPTION OF SYMBOLS 10 Electrostatic spraying device 20 Liquid spray part 21 Body part, 21a Liquid supply port, 21b Liquid flow path, 21c Hole part, 21d Rear end opening part, 21e Female screw structure 22 Liquid nozzle, 22a Front outer peripheral edge, 22b Opening part 23 Mandrel, 23a Pick part, 23b Electrical wiring connection part, 23c Male thread structure, 23d End face 24 Seal member 30 Masking jig 31 Masking body, 31a Hole part 32 Outer conductor, 32a Opening 33 Inner conductor, 33a Second Hole 40 Different pole (Coating object)
41 coating part 42 non-coating part 43 boundary 130 masking jig 132 outer peripheral conductor 50 voltage applying means 60 grounding means TC Taylor cone CL axis

Claims

The liquid is separated from the liquid spraying part in a charged state by electrostatic force generated by applying a voltage between the liquid spraying part and a different polar part having a different polarity with respect to the liquid spraying part. A masking jig used in an electrostatic spraying device for spraying an atomized liquid,
A masking body formed of an insulating material, and a peripheral conductor formed of a conductive material or a semiconductive material,
The masking body is formed with one or a plurality of holes that define an application part for applying a liquid in the object to be coated;
The outer peripheral conductor extends in a normal direction of a plane coinciding with or in contact with the surface where the hole portion of the masking body exists, and is disposed outside an axis passing through the center of gravity of the hole portion, and A masking jig, which is disposed on the liquid spraying portion side of the masking main body and has a different polarity portion in the same potential direction as the object to be coated with respect to the liquid spraying portion.
The masking jig according to claim 1, wherein the outer peripheral conductor has the same potential as the object to be coated.
The masking jig according to claim 1, wherein the outer peripheral conductor is disposed between the object to be coated and the masking main body in the axial direction of the shaft.
The outer circumferential conductor is rotationally symmetric with respect to the axis;
The masking jig according to any one of claims 1 to 3, wherein:
The masking body has a total opening area of the holes of 50 mm 2 or less.
The masking jig according to any one of claims 1 to 4, wherein:
The masking body is formed of a curved surface curved in the axial direction of the shaft.
The masking jig according to claim 1, wherein the masking jig is a masking jig.
The masking jig further includes an inner peripheral conductor formed of a conductive material,
The inner peripheral conductor has a second hole portion having a size equal to or smaller than the hole portion, and the second hole portion is located on the inner side with respect to the shaft than the hole portion.
The masking jig according to any one of claims 1 to 6, wherein:
The masking jig according to claim 7, wherein the inner peripheral conductor is disposed between the object to be coated and the masking body in the axial direction of the shaft.
The masking jig according to claim 7, wherein the inner peripheral conductor is disposed so as to come into contact with the object to be coated.
A liquid spraying section;
A masking jig according to any one of claims 1 to 9,
An electrostatic spraying device.