JP2017100080A - Electrostatic spray method and electrostatic spray device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic spray method and an electrostatic spray device for improving workability of work for coating liquid such as paint on a coating object.SOLUTION: An electrostatic spray method of the present invention is the electrostatic spray method for coating liquid on a coating object 40 by separating the liquid from a nozzle 22 in an electrified state by electrostatic force generated by impressing voltage between a liquid spray part 20 having the nozzle 22 and an unlike pole part (the coating object) 40 of becoming an unlike pole to the liquid spray part 20, and includes a process of coating the liquid on a liquid coating part in a state of not opposing the liquid coating part expected to coat the liquid of the coating object 40 to the nozzle 22, by positioning the coating object 40 in a position for separating from the axis (the Z axis) of the nozzle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrostatic spraying method and an electrostatic spraying apparatus.

  Conventionally, a nozzle that sprays while applying a voltage to a solution material, and a mask that is disposed in the vicinity of the substrate between the nozzle and the substrate and includes an opening having a predetermined opening pattern, is provided from the nozzle. The sprayed solution material is deposited as a thin film on the substrate, and the portion of the opening of the mask on the nozzle side is configured to have an opening area larger than the portion of the opening of the mask on the substrate side. A thin film forming apparatus is known (see Patent Document 1).

JP 2014-147891 A

  By the way, in the usage pattern as in Patent Document 1, it is sufficient that the solution material can be sprayed toward one surface of the substrate. However, when a liquid such as a paint is applied to the object to be coated, Even if the object is flat, it may be required to apply a liquid to both the front and back surfaces.

In such a case, after performing the operation | work which has arrange | positioned so that either the surface side of a flat plate-shaped to-be-coated object side may face a nozzle, and may apply a liquid, the remaining other surface is a nozzle. This is accompanied by the work of turning the object to be placed so as to face the surface, and the workability is not good.
In addition, there is no method for completing liquid coating on both the front and back surfaces simultaneously with a single coating operation.

  This invention is made in view of such a situation, and provides the electrostatic spraying method and the electrostatic spraying apparatus which improved the workability | operativity of the operation | work which applies liquids, such as a coating material, to a to-be-coated article. With the goal.

The present invention is grasped by the following composition in order to achieve the above-mentioned object.
(1) In the electrostatic spraying method of the present invention, a liquid is charged by electrostatic force generated by applying a voltage between a liquid spraying portion having a nozzle and a different polarity portion different from the liquid spraying portion. An electrostatic spraying method in which a liquid is applied to an object by separating the nozzle from the nozzle in a state where the object is positioned at a position separated from an axis of the nozzle and the liquid of the object is applied. A step of applying the liquid to the liquid application portion in a state where the liquid application portion to be applied does not face the nozzle.

(2) In the configuration of (1) above, the step includes changing a separation distance between the object to be coated and the axis of the nozzle.

(3) In the configuration of (2), the change in the separation distance is performed by moving at least one of the article to be coated or the liquid spraying portion in a direction orthogonal to the axis of the nozzle.

(4) In the configuration of (2), the change in the separation distance is performed by changing the direction in which the nozzle faces.

(5) In any one configuration of the above (1) to (3), the liquid application part is at least one of the front surface and the back surface of the flat plate-shaped object to be coated,
The surface to be the liquid application part is made substantially parallel to the axis of the nozzle.

(6) In any one of the constitutions (1) to (5), the step includes changing a distance between the object to be coated and the nozzle.

(7) The electrostatic spraying method of the present invention charges a liquid with electrostatic force generated by applying a voltage between a liquid spraying part having a nozzle and a different polar part having a different polarity with respect to the liquid spraying part. In the electrostatic spraying method of separating the nozzle from the nozzle and applying the liquid to the object to be coated, the liquid application part of the object to be coated with the liquid is a flat plate-like object. Positioning the object to be coated on the axis of the nozzle so that the surface that is at least one of the front surface and the back surface, which is the liquid coating portion, is substantially parallel to the axis of the nozzle, and the liquid A step of applying the liquid to the liquid application portion in a state where the application portion does not face the nozzle.

(8) In the electrostatic spraying method of the present invention, the liquid is charged by electrostatic force generated by applying a voltage between the liquid spraying portion having the nozzle and the different polarity portion different from the liquid spraying portion. In the electrostatic spraying method of separating the nozzle from the nozzle and applying a liquid to the object to be coated, the object to be coated has two application surfaces separated as a liquid application part to be coated with the liquid. And the relative positional relationship between the object to be coated and the liquid spraying portion is such that one straight line connecting an arbitrary point on one application surface of the object to be coated and the tip of the nozzle is an axis of the nozzle. On the other hand, the liquid is simultaneously applied to both of the two application surfaces in a state satisfying the relationship located on the opposite side of the other side straight line connecting the arbitrary point of the other application surface of the object to be coated and the tip of the nozzle. Including the step of applying.

(9) In the configuration of (8), the one side axis is a straight line connecting the position of the substantially center of one application surface and the nozzle, and the other side axis is substantially the center of the other application surface. And the angle between the one-side axis and the nozzle axis is substantially equal to the angle between the other-side axis and the nozzle axis.

(10) In the configuration of the above (8) or (9), the object to be coated has a flat plate shape, and one application surface and the other application surface are the front surface and the back surface of the flat object to be coated. is there.

(11) The electrostatic spraying device of the present invention includes a liquid spraying unit having a nozzle, a rotating unit that rotates the liquid spraying unit so as to change a direction in which the nozzle faces, the liquid spraying unit, and the liquid spraying. A voltage applying means for applying a voltage between the different polar parts with respect to the part to generate an electrostatic force and causing the liquid to be detached from the nozzle in a charged state so that the liquid is applied to the object to be coated. And comprising.

(12) The electrostatic spraying device of the present invention generates electrostatic force by applying a voltage between the liquid spraying unit having a nozzle and the liquid spraying unit and a different polar part different from the liquid spraying unit. Voltage applying means for releasing the liquid from the nozzle in a charged state, and the object to be applied to which the liquid in the charged state released from the nozzle crosses the axis of the nozzle, or Moving means for moving at least one of the liquid spraying units.

(13) In the configuration of the above (11) or (12), a moving unit that moves at least one of the object to be coated or the liquid spraying unit and changes a distance between the object to be coated and the nozzle. Prepare.

  ADVANTAGE OF THE INVENTION According to this invention, the electrostatic spraying method and electrostatic spraying apparatus which improved the workability | operativity of the operation | work which applies liquids, such as a coating material, 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 of the liquid spray part of 1st Embodiment which concerns on this invention. It is an enlarged view of the front end side of the liquid spraying part of FIG. 2, (a) is a figure which shows the case where the front-end | tip of a mandrel is located back, (b) is a front-end | tip of a mandrel located ahead of (a). It is a figure which shows the case where it does. It is an upper surface figure showing the example of the 1st spraying by the electrostatic spraying device of a 1st embodiment concerning the present invention. It is a top view which shows the state which changed the direction which a nozzle faces from the state of FIG. 4 to the right side. It is a top view which shows the 2nd spray example by the electrostatic spraying apparatus of 1st Embodiment which concerns on this invention. It is a top view which shows the whole structure of the electrostatic spraying apparatus of 2nd Embodiment which concerns on this invention. It is a top view which shows the case where the electrostatic spraying apparatus of 1st, 2nd embodiment which concerns on this invention is used for the coating of the liquid to a circular shaped to-be-coated object.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter, 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 an electrostatic spraying device 10 according to a first embodiment of the present invention.
As shown in FIG. 1, the electrostatic spraying device 10 has a liquid spraying unit 20 having a nozzle 22, a rotating unit 30 that rotates the liquid spraying unit 20, and the liquid spraying unit 20 and the liquid spraying unit 20. And a voltage applying means 50 that is a voltage power source for applying a voltage between the different polarity portion 40 that has a different polarity.

In the present embodiment, the case where the electrical wiring from the voltage application means 50 is directly connected to the object to be coated and the object itself is used as the heteropolar portion 40 is shown. For example, the object to be coated is placed. An electrical wiring from the voltage application means 50 is connected to a placement portion (not shown), and the object to be coated is electrically connected to the voltage application means 50 via the placement portion with the placement portion as a different polarity portion 40. It may be connected.
In addition, in this embodiment, since the to-be-coated object itself is made into the different pole part 40, below, the code | symbol 40 is mainly attached | subjected and the code | symbol of a different pole part may be abbreviate | omitted below.

The article to be coated 40 is grounded by the grounding means 60.
This grounding means 60 is not an essential requirement, but in the case of an object to be coated 40, it is preferable to provide it from the viewpoint of safety because an operator may touch it.

(Liquid spray part)
FIG. 2 is a cross-sectional view showing only the liquid spray unit 20.
In FIG. 2, a state in which a liquid such as a paint is sprayed from the liquid spraying unit 20 is illustrated as described later.

  As shown in FIG. 2, 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 through-hole serving as a liquid flow of the body part 21. A nozzle 22 provided at the tip of the body portion 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 body portion 21 and in the through hole of the nozzle 22. Yes.

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, at the rear end of the mandrel 23 located on the rear end side of the 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 almost the center of the knob portion 23a. An electrical wiring connection portion 23b made of the conductive material thus provided is provided.

As shown in FIG. 1, the electrical wiring from the voltage application means 50 is connected to the electrical wiring connection part 23b.
As shown in FIG. 2, the mandrel 23 and the electric wiring connecting part 23 b are electrically connected by the electric wiring connecting part 23 b coming into contact with the mandrel 23.

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

Therefore, the mandrel 23 is removably attached to the body part 21 by screwing the male screw 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.

Here, in general, the nozzle for spraying the liquid of the electrostatic spraying device is a fine liquid passage having a small diameter of the through hole through which the liquid flows.
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 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.

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

  On the other hand, the opening diameter of the opening 22b of the nozzle 22 is preferably 1.0 mm or less, more preferably 0.8 mm or less, and further preferably 0.5 mm or less in consideration of the stability of atomization.

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.
Further, since the inner diameter of the through hole of the nozzle 22 is large enough to allow the mandrel 23 to be disposed, the mandrel 23 can be removed and a large amount of washing liquid can be flowed for washing.

  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 located in front of the state of (a).

  As shown in FIG. 3A, the nozzle 22 has a tapered inner diameter portion (refer to the range W1) having a taper angle α that becomes smaller in taper toward the opening portion 22b. Has a tapered portion (see range W2) having a taper angle β of which the outer diameter becomes smaller toward the distal end surface 23d.

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

  As described above, by forming the tip end side of the nozzle 22 and the mandrel 23, as can be seen by comparing FIG. 3A and FIG. The width of the gap formed by the mandrel 23 can be adjusted, and the amount of liquid exiting from the opening 22b of the nozzle 22 can be adjusted.

In addition, by moving the mandrel 23 further forward than in the state shown in FIG. 3B, the mandrel 23 can abut against the inner peripheral surface of the nozzle 22 to close the opening 22 b of the nozzle 22. It is.
Therefore, it is possible to prevent the liquid in the nozzle 22 from being dried by blocking the opening 22b of the nozzle 22 with the mandrel 23 in a state where the liquid such as paint is not sprayed, and to suppress the clogging of the nozzle 22. it can.

(Different pole part)
In the present embodiment, as shown in FIG. 1, a case is shown in which an object to be coated 40 is used at a different pole portion, and the electric wiring on the opposite side to that connected to the mandrel 23 of the voltage applying means 50 is coated. By being connected to the object 40, the object to be coated 40 itself has a different polarity with respect to the liquid spray unit 20.

(Rotating means)
As shown in FIG. 1, the rotation means 30 includes a support portion 31 and a rotation mechanism portion 32.
One end of the support portion 31 is inserted into the rotation mechanism portion 32, and the support portion 31 is connected to a rotation shaft of a motor (not shown) provided in the rotation mechanism portion 32.

  On the other hand, a ring-shaped holding portion 31a is provided at the other end of the support portion 31, and the body portion 21 of the liquid spraying portion 20 is inserted into the ring-shaped holding portion 31a, so The liquid spray unit 20 is supported.

  Therefore, when the motor (not shown) of the rotation mechanism unit 32 is rotated, the support unit 31 is also rotated, and the liquid spraying unit 20 is rotated, so that the direction in which the nozzle 22 faces can be changed. .

  Next, with reference to FIG. 2, first, a state in which the liquid is sprayed from the liquid spraying unit 20 will be described, and then an electrostatic spraying method using the electrostatic spraying device 10 will be described.

  The liquid supplied to the liquid supply port 21a of the body part 21 is supplied to the tip end side of the nozzle 22, and the electrostatic force accompanying the voltage applied between the workpiece 40 and the mandrel 23, which is a different pole part. As a result, 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 of the nozzle 22 (more precisely, the opening 22b and the mandrel) 23, it is not necessary to be pumped and supplied at such a pressure that the liquid is ejected from the gap 23). In the state where the liquid is ejected vigorously, it may be impossible to atomize.

  More specifically, the electrostatic force that pulls the liquid forward is balanced against the adhesive force due to the surface tension and viscosity of the tip 23d of the liquid mandrel 23 and the outer peripheral edge 22a of the nozzle 22 as shown in FIG. As shown, a tailor cone 80 in which the liquid supplied to the tip side of the nozzle 22 has a conical shape at the tip is formed.

The tailor cone 80 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 nozzle 22 charged with excess charge.
Then, the liquid is pulled straight from the tip of the tailor cone 80 by electrostatic force, and then the liquid is sprayed by electrostatic explosion.

  The liquid to be sprayed, that is, the liquid that has been separated from the nozzle 22 into liquid particles, has a drastically larger area in contact with air than the state before separation, and thus the evaporation of the solvent is promoted. The distance between the charged electrons is reduced as the gas is evaporated, electrostatic repulsion (electrostatic explosion) occurs, and the liquid particles are further 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, a mandrel 23 is provided in the nozzle 22.
Assuming that the mandrel 23 is not provided as in the conventional electrostatic spraying device, the portion to which the liquid can adhere is only the outer peripheral edge 22a of the tip of the nozzle 22.

  When the opening diameter of the opening 22b of the nozzle 22 is increased in such a state, the liquid can be attached only to the outer peripheral edge 22a of the tip of the nozzle 22. This makes it impossible to form a clean tailor cone 80 or to maintain the tailor cone 80 itself, so that the stability of the liquid particles detaching from the nozzle 22 (stability such as particle size, number and charged state) is obtained. As a result, it is surmised that stable atomization of the liquid cannot be achieved.

On the other hand, in this embodiment, the mandrel 23 is disposed in the nozzle 22, and the liquid adheres not only to the outer peripheral edge 22 a of the 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 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 tailor cone 80 can be formed. It is thought that stable atomization is possible.

  If the distal end surface 23d of the mandrel 23 protrudes too far forward from the outer peripheral edge 22a of the nozzle 22 (that is, the distal end surface of the opening 22b of the nozzle 22), the electric field is unlikely to act on the liquid exiting the nozzle 22. If the front end surface 23d of the nozzle 23 is retracted too far backward from the front end surface of the opening 22b of the 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 tip surface 23d of the mandrel 23 is in the front-rear direction along the central axis of the mandrel 23 with respect to the tip surface of the opening 22b of the nozzle 22 in the state where the liquid is sprayed. It is preferably located within 10 times the opening diameter of the opening 22b at the tip, more preferably within 5 times, and even more preferably within 3 times.

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

  Then, the tip of the mandrel 23 reaches the vicinity of the opening 22b of the nozzle 22 so that a conical tailor cone 80 can be formed by an electric field (electrostatic force) acting on the liquid coming out of the tip of the nozzle 22. Therefore, it is preferable to be located within 2 mm forward (outward direction) from the front end surface of the opening 22b of the nozzle 22, while acting on the adhesion of the liquid. In addition, it is preferable that the tip of the mandrel 23 be positioned within 2 mm behind (in the retracting direction) from the tip surface of the opening 22 b of the nozzle 22.

As described above, by providing the mandrel 23, stable atomization of the liquid can be performed even if the opening diameter of the opening 22b of the nozzle 22 is increased.
For this reason, the opening diameter of the opening part 22b of the nozzle 22 can be made into a large opening diameter which can suppress clogging.
Further, since the opening diameter of the opening 22b of the nozzle 22 can be increased, the nozzle 22 can be easily manufactured by machining.

  In the present embodiment, the tip of the mandrel 23 is shown as a flat flat surface as the tip surface 23d. However, the tip of the mandrel 23 is not necessarily a flat flat surface, and the stable tailor cone 80 is formed. Therefore, for example, the tip of the mandrel 23 may be a curved surface protruding toward the front side like an R shape.

  The liquid sprayed from the liquid spraying part 20 (nozzle 22) in this way is atomized while repeating electrostatic explosion, and since the atomized liquid is charged, the object to be coated is a heteropolar part. It is attracted to the 40 side by electrostatic force and applied to the article 40 to be coated.

An electrostatic spraying method for applying a liquid to the article 40 using the electrostatic spraying device 10 as described above will be described.
(First spray example)
FIG. 4 is a top view showing a first spray example in an electrostatic spraying method in which a liquid is applied to the article 40 using the electrostatic spraying device 10.
In FIG. 4, the voltage applying unit 50 and electric wiring from the voltage applying unit 50 are omitted.

As shown in FIG. 4, in the first spraying example, the liquid application part to be applied with the liquid of the flat plate-like object 40 has one surface 40 a and one surface 40 a on the surface or the back surface of the object 40 or the surface or The case where it is set as both surfaces of the other surface 40b of the back surface is shown.
That is, the to-be-coated object 40 of the first spray example has two application surfaces (a front surface and a back surface) that are spaced apart from each other as a liquid application portion on which a liquid is to be applied.

  Also, the Z-axis indicated by the dotted arrow in FIG. 4 is the axis of the nozzle 22, and as can be seen from FIG. 4, the surfaces 40 a and 40 b that become the liquid coating portions are substantially parallel to the Z-axis that is the axis. In addition, the object 40 is positioned on the Z axis, which is the axis, and the surfaces 40 a and 40 b that are the liquid application portions are not opposed to the nozzle 22.

  Furthermore, in the example shown in FIG. 4, the relative positional relationship between the object to be coated 40 and the liquid spraying unit 20 is such that an arbitrary point on one surface 40 a (one application surface) of the object to be coated 40 and the tip of the nozzle 22. Is opposite to the other straight line connecting an arbitrary point of the other surface 40b (the other application surface) of the article 40 and the tip of the nozzle 22 with respect to the axis (Z axis) of the nozzle 22. It is assumed that the relationship located on the side is satisfied.

  In particular, the one side axis is a straight line L1 that connects the position of the substantially center of one application surface (one surface 40a) and the nozzle 22, and the other side axis is the substantially center of the other application surface (the other surface 40b). The angle θ between the one side axis (see L1) and the axis of the nozzle 22 (Z axis) is equal to the other side axis (see L2) and the axis of the nozzle 22 (see L2). The angle γ with respect to the Z axis) is almost equal.

  And when spraying of the liquid is started in such a state, the liquid sprayed from the liquid spraying part 20 spreads over a wide range due to electrostatic explosion, but the article 40 itself is a heteropolar part, As shown by the arrows in FIG. 4, the liquid is applied to the surfaces 40 a and 40 b to be the liquid application portions by being attracted by electrostatic force.

  For this reason, since it is possible to complete the liquid application simultaneously on the front surface and the back surface of the object to be coated 40 by one application operation, the nozzle 22 and the surface of the object to be coated 40 are opposed to each other as in the prior art. After the liquid is applied to the surface, the direction of the object to be coated 40 is turned over so that the back surface and the nozzle 22 face each other and the liquid is applied to the back surface. Work becomes unnecessary, and workability can be improved.

  In the above description, the case where one application surface (one surface 40a) and the other application surface (the other surface 40b) are substantially parallel during the thickness separation of the object 40 is shown. However, for example, the thickness of the object to be coated 40 increases as it goes away from the liquid spraying unit 20, and one application surface (one surface 40a) and the other application surface (the other surface 40b) are It may be an inclined surface in which the separation distance gradually increases.

On the other hand, depending on how the sprayed liquid spreads and the size of the object to be coated 40, the liquid to be sprayed up to the portions of the surfaces 40a and 40b, which are liquid coating portions located on the side away from the liquid spraying portion 20, In some cases, it does not reach and uneven coating occurs.
It should be noted that the portions of the surfaces 40a and 40b that are the liquid application portions located on the side away from the liquid spraying portion 20 may be described as the far sides of the surfaces 40a and 40b.

  However, as described above, the electrostatic spraying device 10 of the present embodiment is configured to be able to rotate the liquid spraying unit 20 by the rotating means 30, and therefore, the nozzle 22 is provided with both the nozzles shown in FIG. The direction can be changed in the direction of the arrow.

  For this reason, for example, as shown in FIG. 5, when the liquid spraying unit 20 is rotated so that the nozzle 22 faces the right side, the sprayed liquid is sprayed so as to spread more widely in the space on the surface 40b side. The liquid sprayed to the far side of 40b reaches, and the liquid sprayed to the far side is attracted by the electrostatic force to the surface 40b of the article 40 and directly applied to the surface 40b. The liquid can be applied so that there is no coating unevenness.

  Conversely, although not shown, when the liquid spraying unit 20 is rotated so that the nozzle 22 faces the left side, the liquid sprayed reaches the far side of the surface 40a and reaches the far side of the surface 40b. The liquid can be applied so that there is no coating unevenness.

As described above, when the nozzle 22 is directed to the right side or the left side, the direction of the Z axis that is the axis of the nozzle 22 also changes, and in this state, the object to be coated 40 is based on the Z axis that is the axis of the nozzle 22. It is in the state located in the position spaced apart in the direction which cross | intersects from 22 axes (refer FIG. 5).
Even in this state, the surfaces 40 a and 40 b that are the liquid application portions to be applied with the liquid remain in a state of not facing the nozzle 22.

  Accordingly, the object to be coated 40 is located at a position separated from the axis (Z axis) of the nozzle 22 in the direction intersecting with the axis (Z axis) of the nozzle 22 (see the thick arrow A in FIG. 5). Including the step of applying the liquid to the liquid application part (surface 40b) in a state where the liquid application part (surface 40b) to be applied with the liquid 40 does not face the nozzle 22, the occurrence of application unevenness Can be suppressed.

  5 shows the case where the nozzle 22 is directed to the right side. However, when the nozzle 22 is directed to the left side, the axis of the nozzle 22 is based on the axis (Z axis) of the nozzle 22 when the article 40 is to be coated. The liquid application part (surface 40a) is located in a position separated from the (Z axis) in a direction intersecting with the liquid application part (surface 40a) to which the liquid of the object 40 is to be applied and does not face the nozzle 22. By including the step of applying the liquid in 40a), the occurrence of uneven coating can be suppressed.

  Therefore, the electrostatic spraying method according to the present invention is located at a position where the object to be coated 40 is separated from the axis (Z axis) of the nozzle 22 in the direction intersecting the axis (Z axis) of the nozzle 22. By including a step of applying a liquid to the liquid application part (surfaces 40a, 40b) in a state where the liquid application part (surfaces 40a, 40b) to be applied with the liquid of the object 40 does not face the nozzle 22, The occurrence of coating unevenness can be suppressed.

  In the first spraying example, the case where both the front and back surfaces (surfaces 40a and 40b) of the object to be coated 40 have been described as the liquid application portion where the liquid is to be applied. In some cases, the liquid application part to be applied is only one surface 40a or the other surface 40b of the front surface or the back surface of the object 40 to be coated.

  For example, when the liquid is applied only to the other surface 40b, the position where the article 40 is separated in the direction intersecting the axis (Z axis) of the nozzle 22 with respect to the axis (Z axis) of the nozzle 22 from the beginning. (Refer to the thick arrow A in FIG. 5), and the other surface 40b, which is the liquid application part to which the liquid of the object 40 is to be applied, does not face the nozzle 22, the liquid application part You may make it implement the process of applying a liquid to a certain other surface 40b.

  Similarly, when liquid is applied only to one surface 40a, the nozzle 22 is directed to the left side in FIG. 5 from the beginning, so that the article 40 is based on the axis (Z axis) of the nozzle 22. The one surface 40a, which is a liquid application portion to be applied with the liquid of the object 40, is not opposed to the nozzle 22 at a position that is separated from the axis (Z axis) of the nozzle 22 Thus, a step of applying a liquid to one of the liquid application portions 40a may be performed.

  That is, when the liquid application part where the liquid is to be applied is only one surface 40a or the other surface 40b of the front surface or the back surface of the object 40, the object 40 is the axis of the nozzle 22 (Z axis). One surface 40a or the other surface 40b, which is a liquid application portion that is to be applied with the liquid of the object 40, is located in a position that is separated from the axis (Z axis) of the nozzle 22 with reference to In a state where the liquid does not face the nozzle 22, a step of applying a liquid to one of the liquid application portions 40 a or the other surface 40 b may be performed.

  Further, the step of applying the liquid to the object to be coated 40 is not required to be performed while the nozzle 22 is stopped, and the object to be coated 40 is moved while moving the nozzle 22 to the left or right while the liquid is being sprayed. You may make it apply a liquid to.

When the direction in which the nozzle 22 faces is changed in this way, the axis line (Z axis) of the nozzle 22 is in a state of approaching or leaving the workpiece 40.
That is, the step of applying the liquid to the object to be coated 40 may include changing the separation distance between the object to be coated 40 and the axis line (Z axis) of the nozzle 22.

In addition, when the article 40 is large in the vertical direction, if the liquid spray unit 20 can be moved in the vertical direction (vertical direction), good liquid application can be performed in the vertical direction.
For this reason, for example, a vertical movement means may be provided, and the rotation means 30 may be mounted on the vertical movement means.

(Second spray example)
In the above description, the case where the liquid is sprayed without changing the distance between the liquid spraying unit 20 and the object to be coated 40 is shown. However, as in the second spraying example shown in FIG. Also good.

  Specifically, as shown in FIG. 6, for example, in a state where the nozzle 22 faces the right side, the distance between the object to be coated 40 and the liquid spray unit 20 indicated by the thick double arrow B is shortened, and the liquid The spray unit 20 may be positioned near the object to be coated 40, or conversely, the liquid spray unit 20 may be positioned far from the object to be coated 40 by increasing the distance.

As shown in FIG. 6, when the liquid spray unit 20 is positioned near the object 40, the nozzle 22 is positioned near the object 40 as indicated by an arrow C. The liquid spray start point is located near the object to be coated 40.
Conversely, when the liquid spraying unit 20 is positioned far from the object to be coated 40, the liquid spray start point is positioned far from the object to be coated 40.

  In this way, the approach distance of the liquid on the surface 40b of the object 40 can be changed by moving the spray start point closer to or away from the object 40, so that the surface 40b is far away. The liquid can reach the side, or conversely, the liquid does not reach the side far from the surface 40b, and the liquid can be applied only to the side close to the liquid spraying unit 20.

  In addition, the liquid spraying unit 20 may be continuously brought close to or separated from the object to be coated 40 while the liquid is being sprayed. The liquid can be uniformly and uniformly applied to 40b.

Note that the method of changing the distance between the liquid spray unit 20 and the object to be coated 40 as described above need not be limited to moving the liquid spray unit 20 so as to be close to or away from the object to be coated 40. Conversely, the article 40 may be moved so as to approach or separate from the liquid spray unit 20.
Furthermore, the distance between the liquid spray unit 20 and the object to be coated 40 may be changed by moving both the liquid spray unit 20 and the object to be coated 40.
That is, distance changing means for changing the distance between the liquid spray unit 20 and the object to be coated 40 may be provided on at least one of the object to be coated 40 side or the liquid spray unit 20 side.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described with reference to FIG.
The electrostatic spraying device 10 ′ of the second embodiment is different from the first embodiment only in that a moving means 70 is added to the configuration of the electrostatic spraying device 10 of the first embodiment. It is the same.
Therefore, this different point will be mainly described, and description of similar points may be omitted.

  In the electrostatic spraying apparatus 10 ′ of the second embodiment, the rotating means 30 is provided on a moving means 70 such as a conveyor, for example. By this moving means 70, a thick arrow in FIG. As shown to D, the liquid spraying part 20 can be moved to the right side or the left side by moving the whole rotation means 30 to the right side or the left side.

  That is, it is possible to move the liquid spray unit 20 in a direction orthogonal to the Z-axis that is the axis of the nozzle 22, and when the liquid spray unit 20 is moved to the right side, as shown by the arrow D1 in FIG. 22 also moves to the right side, and conversely, when the liquid spray unit 20 is moved to the left side, the nozzle 22 also moves to the left side as indicated by an arrow D2.

  When the nozzle 22 moves to the right side, the liquid spray start point also moves to the right side, so that the liquid is sprayed more widely in the space on the surface 40b side of the article 40, and the nozzle 22 in the first embodiment. The liquid can reach the far side of the surface 40b in the same manner as when the direction facing is directed to the right side, and the occurrence of coating unevenness can be suppressed.

  Further, if the nozzle 22 is moved to the left side, the liquid can reach the far side of the surface 40a as in the first embodiment when the direction in which the nozzle 22 faces is directed to the left side. Occurrence can be suppressed.

In the present embodiment, the rotating means 30 is provided on the moving means 70, but the rotating means 30 is omitted by providing a supporting portion for supporting the liquid spray unit 20 on the moving means 70. You may do it.
In the above description, only the movement of the liquid spray unit 20 by the moving unit 70 has been described. In addition, the liquid spray unit 20 is rotated by the rotation unit 30 to change the direction in which the nozzle 22 faces. May be.

  Furthermore, in the above description, the liquid spray unit 20 side is moved, so that the article to be coated 40 can be positioned on the right side or the left side of the axis (Z axis) of the nozzle 22. Since this movement only needs to realize a similar movement when viewed relatively, the object 40 can be moved so as to cross the axis (Z axis) of the nozzle 22 when viewed relatively. It only has to be.

  Therefore, by moving the object to be coated 40 in a direction perpendicular to the axis (Z axis) of the nozzle 22, the movement of the object to be coated 40 across the axis (Z axis) of the nozzle 22 is realized. Alternatively, both the object to be coated 40 and the liquid spray unit 20 are moved in a direction orthogonal to the axis (Z axis) of the nozzle 22 so that the object to be coated 40 has an axis (Z axis) of the nozzle 22. You may make it implement | achieve the movement which crosses.

  In the step of applying the liquid to the object 40 using the electrostatic spraying apparatus 10 'of the second embodiment, the relative movement between the nozzle 22 and the object 40 is performed in this way. In the same manner as described in the first embodiment, the distance between the workpiece 40 and the axis (Z axis) of the nozzle 22 (see the thick double arrow E in FIG. 7) is changed. It may be.

  In addition, as described in the first embodiment, a distance changing unit that changes the distance between the object to be coated 40 and the liquid spraying part 20 is provided, and the distance between the object to be coated 40 and the liquid spraying part 20 is provided. May be changed.

  By the way, in the case of the second embodiment, a plurality of objects to be coated 40 are continuously arranged on the axis of the nozzle 22 by providing means for moving the object to be coated 40 in a direction orthogonal to the axis (Z axis) of the nozzle 22. If it is possible to cross (Z axis), it is preferable because the liquid can be efficiently applied to both surfaces (front surface and back surface) of the plurality of objects to be coated 40.

  In this case, for example, a conveyor-type moving means for moving the article to be coated 40 in a direction orthogonal to the axis (Z axis) of the nozzle 22 is provided, and the article to be coated 40 of the moving means is placed. If the part is electrically connected to the voltage applying means 50 (see FIG. 1), the object to be coated 40 is simply placed on the placing part by applying the voltage applying means 50 (see FIG. 1). (See FIG. 1).

As mentioned above, although this invention has been described based on specific embodiment, this invention is not limited to the said embodiment.
In the above description, the plate-shaped object has been mainly described as the object to be coated 40. However, the shape of the object to be coated 40 is not limited to a plate-shaped object. For example, the object to be coated 40 may be a column or a cylinder. It is possible to use a liquid coating portion where the entire circumference of the outer peripheral surface is coated with a liquid.

As shown in FIG. 8, in the case of a cylindrical article 40 having a large diameter, the liquid is satisfactorily applied to the front side portion 40c (refer to the range indicated by the double arrow) that faces the nozzle 22. Can be made.
However, in the case where the object to be coated 40 and the nozzle 22 are opposed to each other, a liquid is applied to a portion 40d (refer to a range indicated by a double arrow) on the side of the object to be coated 40 on the side or the back side located on the opposite side of the front. It may be difficult to apply.

Even in such a case, as shown in FIG. 8, when the liquid spray unit 20 is moved so that the nozzle 22 is positioned on the right side (see arrow F), the liquid is electrostatically applied to the right side of the article 40. In addition to being drawn and applied, the liquid that has passed without being applied to the right side is attracted and applied to the back side by electrostatic force (see dotted arrows in FIG. 8).
Therefore, it is possible to satisfactorily apply the liquid to the right half of the portion 40d such as the back side located on the right side or the front side of the article 40.

Although not shown, when the liquid spraying unit 20 is moved so that the nozzle 22 is positioned on the left side, the portion 40d such as the left side of the article to be coated 40 or the back side positioned on the side opposite to the front side is now displayed. Of these, the liquid can be satisfactorily applied to the left half surface.
As a result, the liquid can be satisfactorily applied to the entire circumference of the outer peripheral surface of the object to be coated 40 without performing an operation such as rotating the object to be coated 40.

  In the example illustrated in FIG. 8, the liquid spray unit 20 is moved in order to move the position of the nozzle 22 to the right side or the left side. By rotating 20, the direction in which the nozzle 22 faces may be directed to the right side or the left side.

  As described above, the present invention is not limited to the above specific embodiments, 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 'Electrostatic spraying device 20 Liquid spraying 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 Nozzle 22a Tip outer peripheral edge 22b Opening part 23 Mandrel 23a Knob part 23b Electrical wiring connection portion 23c Male screw structure 23d Tip surface 24 Seal member 30 Rotating means 31 Support portion 31a Holding portion 32 Rotating mechanism portion 40 Different pole portion (object to be coated)
40a, 40b Surfaces 40c, 40d Portion 50 Voltage applying means 60 Grounding means 70 Moving means 80 Tailor cone

Claims (13)

An electrostatic force generated by applying a voltage between a liquid spray portion having a nozzle and a different polarity portion different from the liquid spray portion causes the liquid to be detached from the nozzle in a charged state and applied to the object to be coated. An electrostatic spraying method for applying a liquid,
The liquid is applied to the liquid application part in a state where the object to be coated is located at a position away from the axis of the nozzle and the liquid application part to which the liquid of the object is to be applied does not face the nozzle. An electrostatic spraying method comprising a step of applying.   The electrostatic spraying method according to claim 1, wherein the step includes changing a separation distance between the object to be coated and an axis of the nozzle.   3. The electrostatic according to claim 2, wherein the change in the separation distance is performed by moving at least one of the article to be coated or the liquid spraying portion in a direction orthogonal to the axis of the nozzle. Spraying method.   The electrostatic spraying method according to claim 2, wherein the change in the separation distance is performed by changing a direction in which the nozzle faces. The liquid application part is at least one surface of the front surface or the back surface of the plate-shaped object to be coated,
The electrostatic spraying method according to any one of claims 1 to 3, wherein a surface to be the liquid application part is substantially parallel to an axis of the nozzle.   The electrostatic spraying method according to claim 1, wherein the step includes changing a distance between the object to be coated and the nozzle. A liquid is discharged from the nozzle in a charged state by an electrostatic force generated by applying a voltage between a liquid spraying portion having a nozzle and a different polarity portion different from the liquid spraying portion. An electrostatic spraying method of applying
The liquid application part to which the liquid of the object to be coated is to be applied is at least one surface of the front surface or the back surface of the flat object,
The liquid is applied in a state where the object to be coated is positioned on the axis of the nozzle so that the surface to be the liquid application portion is substantially parallel to the axis of the nozzle, and the liquid application portion does not face the nozzle. An electrostatic spraying method comprising a step of applying the liquid to an application portion. A liquid is discharged from the nozzle in a charged state by an electrostatic force generated by applying a voltage between a liquid spraying portion having a nozzle and a different polarity portion different from the liquid spraying portion. An electrostatic spraying method of applying
The object to be coated has two application surfaces spaced apart as a liquid application part to be applied with the liquid,
The relative positional relationship between the object to be coated and the liquid spray portion is such that one side straight line connecting an arbitrary point on one application surface of the object to be coated and the tip of the nozzle is relative to the axis of the nozzle, The liquid is simultaneously applied to both of the two application surfaces in a state satisfying a relationship located on the opposite side of the other side straight line connecting the arbitrary point of the other application surface of the object to be coated and the tip of the nozzle. An electrostatic spraying method comprising a step. The one-side axis is a straight line connecting the nozzle and the substantially central position of the one application surface;
The other-side axis is a straight line connecting the nozzle and the substantially central position of the other application surface;
The electrostatic spraying method according to claim 8, wherein an angle between the one-side axis and the axis of the nozzle is substantially equal to an angle between the other-side axis and the axis of the nozzle. The object to be coated is flat.
10. The electrostatic spraying method according to claim 8, wherein the one coated surface and the other coated surface are a front surface and a back surface of the flat plate-like object to be coated. A liquid spraying section having a nozzle;
Rotating means for rotating the liquid spraying part so as to change the direction in which the nozzle faces;
A voltage is applied between the liquid spray portion and a different polarity portion that is different from the liquid spray portion to generate an electrostatic force, and the liquid is charged in a charged state so that the liquid is applied to the object to be coated. An electrostatic spraying device comprising: voltage applying means for separating from the nozzle. A liquid spraying section having a nozzle;
A voltage applying means for generating a static force by applying a voltage between the liquid spraying portion and a different polarity portion different from the liquid spraying portion, and separating the liquid from the nozzle in a charged state;
Moving means for moving at least one of the object to be coated or the liquid spraying section so that the object to be coated with the charged liquid separated from the nozzle crosses the axis of the nozzle. An electrostatic spraying device characterized by that.   The moving means for moving at least one of the object to be coated or the liquid spraying unit to change the distance between the object to be coated and the nozzle is provided. Electrostatic spraying device.

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