JP2005305210A - Coating apparatus and coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus and a coating method for sufficiently micronizing a coating material so as to applying coating of high quality without causing the wasted coating material, while coating equipment is made simple. <P>SOLUTION: According to this invention, the above coating apparatus can be realized. The apparatus is provided with an ejection hole for ejecting the pressurized coating material, an opening/closing valve for opening or closing the ejecting hole, and a drive device for driving the opening/closing valve to intermittently open or close the hole, wherein continuous opening time of the ejection hole is controlled to be shorter than the time until the coating material ejected from the ejection hole reaches a coating surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coating apparatus and a coating method, and more particularly to an apparatus and a method for atomizing a paint and spraying it onto a painted surface.

  When painting the body of an automobile, the paint is atomized and sprayed onto the painted surface. For this type of coating apparatus, a system using a rotary atomizing spray gun, a system using an air spray gun, and a system using an airless spray gun have been put into practical use.

  In the spray gun of the rotary atomization system, the paint is atomized by colliding the paint that is continuously sprayed from the spray hole with the rotating atomizer. According to the rotary atomization method, the atomization of the paint is promoted by the collision between the rotating atomizer and the paint. However, since the spray range of the atomized paint is excessively diffused, it is necessary to apply a potential difference between the paint to be sprayed and the painted surface, and to attach the paint to the painted surface by electrostatic attraction. When a rotary atomizing spray gun is used, charging equipment is required, and safety measures for workers are indispensable, and the painting equipment becomes large.

In an air-type spray gun, the paint sprayed continuously from the spray hole is atomized by a compressed air flow. For example, Patent Documents 1 and 2 disclose the structure of an air-type spray gun. In the air type spray gun, the paint is continuously sprayed from the spray holes, and the paint is atomized by the compressed air flow ejected from the annular air holes formed around the paint spray holes. When an air type spray gun is used, the paint sprayed from the spray hole can be effectively atomized by the compressed air flow. However, since the paint accelerated by the compressed air flow rebounds on the paint surface, the paint is wasted.
JP-A-8-24726 JP-A-9-206637

  In recent years, airless spray guns have been developed. In an airless spray gun, pressurized paint is continuously sprayed from the injection holes, and the sprayed paint is atomized by mixing with the outside air. Use of an airless spray gun simplifies the painting equipment. In addition, since no compressed air is used, the flow rate of the paint reaching the painted surface is low, and there is little rebound from the painted surface. Waste of paint can be saved. However, in the method in which pressurized paint is continuously sprayed from the injection holes, the atomization of the paint cannot be sufficiently promoted. With a normal airless spray gun, the particle size of the paint becomes 100 μm or more, and high-quality coating cannot be obtained. In order to obtain a high-quality coating, it is necessary to atomize the paint to about 40 μm.

  In the rotary atomization type spray gun, charging equipment is required, and coating equipment becomes large. In an air-type spray gun, paint rebounds on the painted surface, resulting in waste of paint. In the airless spray gun, the atomization of the paint is insufficient and a high-quality coating cannot be obtained.

  The present invention solves the above problems. The present invention provides a coating apparatus and a coating method capable of simplifying the coating equipment, hardly causing waste in the paint, sufficiently atomizing the paint, and obtaining a high-quality paint.

  The present invention can be embodied in a coating apparatus. The coating apparatus includes an injection hole that injects pressurized paint, an on-off valve that opens and closes the injection hole, and a drive device that drives the on-off valve to open and close the injection hole intermittently. Here, the time for which the spray holes are continuously opened is adjusted to be equal to or less than the time until the paint sprayed from the spray holes reaches the painted surface.

When the coating material is continuously sprayed from the spray holes, a distribution range of the paint particle groups continuously extending from the spray holes to the coating surface is formed.
On the other hand, if the paint is sprayed intermittently from the spray hole and the paint spray is stopped before the paint sprayed from the spray hole reaches the paint surface, The distribution range does not continue from the spray hole to the painted surface, but becomes a lump of paint particle groups toward the painted surface. It was confirmed that the atomization of the paint particle group was promoted when the distribution range of the paint particle group did not extend from the injection hole to the painted surface but became a lump of the paint particle group toward the painted surface.
The reason is not always clear, but for example
(1) The outside air circulates in front of and behind the lump of the paint particle group, which increases the chance of collision between the paint and the outside air, and promotes atomization of the paint.
(2) The outside air located in front of the coating particle group lump reduces the flying speed of the coating particle group lump and increases the time it takes to reach the coating surface from the spray hole, further promoting atomization of the coating. It is presumed that it is due to being done.
If the paint is sprayed intermittently under conditions where the paint spray is interrupted before the paint sprayed from the spray hole reaches the paint surface, atomization of the paint particle group is promoted and a high-quality paint is obtained. be able to.
A fuel injection valve developed for supplying fuel to the engine can be used to intermittently open and close the injection hole by the on-off valve to inject the paint intermittently. The fuel injection valve can open and close the injection hole intermittently in a very short time, and the distribution range of the paint particle group injected from the injection hole is not continuous from the injection hole to the coating surface, and becomes a lump of paint particle group. The relationship toward the painted surface can be easily obtained.
When the spray gun has two or more spray holes, it is possible to open the other spray hole and spray the paint while one spray hole is closed. In this case, when the entire spray gun is viewed, the paint is sprayed continuously. On the other hand, when the individual injection holes are seen, the paint is intermittently injected. Even with this method, atomization of the paint can be promoted. Whether or not the paint is intermittently ejected should be considered in units of injection holes. Even if the spray gun is continuously sprayed when looking at the entire spray gun, if the paint is sprayed intermittently when looking at the individual spray holes, it should be evaluated that the paint is sprayed intermittently. Can do.
The spray gun of the present invention basically does not use air. The atomization of the paint can be promoted without using air. However, the auxiliary use of air is not excluded. It is possible to further promote atomization by using air as an auxiliary.

When coating is performed using the coating apparatus of the present invention, the coating is usually performed while adjusting the position and angle of the injection hole with respect to the coating surface. In such a case, it is desirable that the worker who performs the coating instructs the start and end of the coating. Alternatively, it is desirable to have a configuration in which the painting apparatus is instructed to start and finish painting in synchronization with the operation of the robot that operates the spray gun.
When a paint start signal and a paint end signal are input to the coating device, the paint start signal and the paint end signal are input, and the on-off valve is input after the paint start signal is input until the paint end signal is input. It is preferable to use a control device that drives and intermittently opens and closes the injection holes.
In the conventional painting apparatus, the paint is continuously ejected from the injection hole until the painting end signal is inputted after the painting start signal is inputted. However, if the above-described control device is prepared, the paint is continuously ejected from the ejection hole until the painting end signal is inputted after the painting start signal is inputted. By promoting atomization of the paint particle group, it is possible to paint with high quality.
If a painting end signal is input, the injection hole is continuously closed and the paint is not injected.

The coating apparatus of the present invention basically does not use compressed air. For this reason, the spray gun can be reduced in size, and a plurality of spray guns can be arranged in parallel corresponding to the spread of the painted surface.
When a plurality of spray guns are driven simultaneously, it is possible to paint over a wide range at the same time. For example, when painting a wide range such as an automobile bonnet, the paint is intermittently ejected from all the paint spraying devices arranged in parallel. Further, when painting a narrow range such as a bumper of an automobile, it is possible to drive only the paint spraying device selected according to the paint range and to spray the paint locally and intermittently.
According to this coating apparatus, it is possible to perform coating on a painted surface of various shapes without causing waste of paint while using the same coating apparatus.

The present invention can also be understood as a novel coating method. In the coating method of the present invention, coating is performed while intermittently spraying pressurized paint from the spray holes from the start of painting to the end of painting. The time during which the paint is continuously sprayed is set to be equal to or less than the time until the paint sprayed from the spray hole reaches the painted surface.
When the paint is intermittently ejected, a lump of paint particle groups is formed between the spray hole and the painted surface, and the lump flies toward the painted surface. The atomization of the paint is promoted, and sufficiently atomized paint particles adhere to the painted surface. Although it is basically an airless system, it is possible to realize a high-quality coating in which the paint is sufficiently atomized.

Another coating method of the present invention is to arrange the coating devices embodied in the present invention in parallel, select a coating device corresponding to the spread of the painted surface, and drive only the selected coating device. Features.
The coating apparatus embodied in the present invention basically does not use air, and the spray gun can be miniaturized. By arranging a plurality of miniaturized spray guns in parallel and selecting a spray gun that can be driven according to the spread of the paint surface, various paint spray patterns can be realized and which spray pattern is used. However, high quality coating can be realized by intermittent spraying of the paint.
When a plurality of spray guns are driven simultaneously, it is possible to paint over a wide range at the same time. For example, when painting a wide range such as an automobile bonnet, the paint is intermittently ejected from all the paint spraying devices arranged in parallel. Further, when painting a narrow range such as a bumper of an automobile, it is possible to drive only the paint spraying device selected according to the paint range and to spray the paint locally and intermittently.

  According to the technique of the present invention, although it is basically an airless system, it is possible to sufficiently atomize the paint and realize high-quality painting.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. First, the main features of the embodiment are listed.
(Embodiment 1): The coating apparatus includes a paint supply path for introducing pressurized paint, an injection hole for injecting the supplied paint, an opening / closing valve for opening / closing the injection hole, and an injection hole by driving the opening / closing valve. Drive means for intermittently opening and closing. The time for which the spray holes are continuously opened is equal to or shorter than the time until the paint sprayed from the spray holes reaches the painted surface.
(Mode 2): The time during which the on-off valve is continuously opened is 1 ms or less. Between the spray hole and the painted surface, a lump of paint particle groups exposed to the front and back is formed.

(First embodiment)
FIG. 1 is a diagram schematically showing a coating apparatus 2 of the present invention. The case 30 of the coating apparatus 2 has a cylindrical space inside, and the space communicates with the outside through the orifice 12 and the injection hole 14 at one end of the case 30. A movable body 26 is slidably accommodated inside the case 30. The movable body 26 includes a valve 16 (corresponding to an on-off valve) and an armature 18. The armature 18 made of a magnetic material is formed in a cylindrical shape, and is slidably provided in the case 30. A valve 16 is integrally connected to an end face of the armature 18 on the side close to the injection hole 14. The valve 16 includes a cylindrical shaft member. One end of the shaft member is connected to the armature 18, and a ball 32 is integrally fixed to the other end. The shaft member of the valve 16 has a hole through which the paint can flow from the inside of the valve 16 to the outside. A return spring 24 is provided on the other end face of the armature 18 to urge the armature 18 toward the injection hole 14 so that the ball 32 fixed to the tip of the valve 16 contacts the seat 34.
A paint chamber 4 is formed inside the case 30 via the armature 18 and the valve 16. The paint chamber 4 is connected to the paint tank 6 via the paint supply path 8. The paint is pressurized and sent from the paint tank 6 to the paint chamber 4 by a pump 10 provided in the paint supply path 8. The paint chamber 4 communicates with the injection hole 14 via the orifice 12 when the ball 32 and the sheet 34 are not in contact with each other. When the ball 32 and the seat 34 are in contact with each other, the connection between the paint chamber 4 and the injection hole 14 is interrupted.

The case 30 is provided with an electromagnetic coil 22 that is energized by a signal from the controller 28. When energized, the electromagnetic coil 22 applies an electromagnetic force to the armature 18, and moves the armature 18 away from the injection hole 14 against the urging force of the return spring 24.
A stopper 20 is provided on the inner surface of the case 30. The stopper 20 is an annular projection provided on the opposite side of the injection hole 14 when viewed from the armature 18 and restricts the movable range of the armature 18.
The controller 28 inputs the painting start signal and the painting end signal, and intermittently turns on and off the current applied to the electromagnetic coil 22 after the painting start signal is inputted and before the painting end signal is inputted. In FIG. 1, the paint start signal is indicated by a change from low to high, the paint end signal is indicated by a change from high to low, and the time when the paint end signal is input from time t1 when the paint start signal is input. Until t2, the controller 28 applies current for 1 ms to the electromagnetic coil 22 so as to de-energize for 1 ms. The injection hole 14 is repeatedly opened for 1 ms and then closed for 1 ms.

The operation of the coating apparatus 2 will be described. The paint in the paint tank 6 is pressurized by the pump 10 and fed into the paint chamber 4 of the coating apparatus 2 via the paint supply path 8. In a state in which the energization signal is not transmitted from the controller 28 to the electromagnetic coil 22, the armature 18 is loaded by the return spring 24 in the right direction in FIG. 1 and is held at a position where the ball 32 contacts the seat 34. In this state, there is a gap that cannot be illustrated between the armature 18 and the stopper 20. In a state where the ball 32 is in contact with the seat 34, the space between the paint chamber 4 and the injection hole 14 is blocked by the valve 16, and the paint flowing into the paint chamber 4 is in a pressurized state in the paint chamber 4. Stays inside.
When an energization signal is transmitted to the electromagnetic coil 22 by the controller 28, the electromagnetic coil 22 is energized. Electromagnetic force acts on the armature 18 by the electromagnetic coil 22, and the armature 18 moves toward the left in FIG. 1 against the urging force of the return spring 24 and collides with the stopper 20. The armature 18 is held at the collision position by the electromagnetic force of the electromagnetic coil 22, the ball 32 is separated from the seat 34, and the paint chamber 4 and the injection hole 14 communicate with each other through the orifice 12. The pressurized paint staying in the paint chamber 4 flows into the orifice 12 through a small gap between the ball 32 and the seat 34 and is jetted from the jet hole 14.
When the energization signal from the controller 28 stops, the electromagnetic coil 22 stops energization. The electromagnetic force acting on the armature 18 disappears, the armature 18 moves to the right in FIG. 1 by the urging force of the return spring 24, and the ball 32 fixed to the tip of the valve 16 comes into contact with the seat 34. And stop. The space between the paint chamber 4 and the spray hole 14 is blocked, and the spray of paint from the spray hole 14 is stopped.
The controller 28 repeatedly transmits a low potential and a high potential as energization signals to the electromagnetic coil 22. As a result, the armature 18 repeatedly moves in the case 30 and the spraying and stopping of the paint from the spray holes 14 are repeated.

The paint sprayed from the spray holes 14 diffuses and moves toward the paint surface W while being atomized.
Since the spray hole 14 forms a tapered shape that extends toward the outlet, the paint moves to the coating surface W while being diffused in a tapered shape even after being sprayed from the spray hole 14.
The coating material sprayed from the spray holes 14 diffuses toward the coating surface W, and the contact area with the outside air increases. Before reaching the paint surface W, the paint particles and the outside air are mixed, and the paint particles are atomized.

The time for the paint to reach the coating surface W from the injection hole 14 is about 10 ms. On the other hand, since the paint is intermittently ejected from the injection holes 14 and the time for which the paint is continuously ejected is 1 ms, the sprayed paint forms a paint particle cluster 36 as shown in FIG. Then move to the painted surface W.
When the paint is intermittently ejected from the ejection holes 14, there is an atmosphere before and after the ejected paint particle cluster 36 unlike the case where the paint is continuously ejected. For this reason, the collision chance of the sprayed paint particle cluster 36 and the atmosphere increases, and the atomization of the paint is promoted. Furthermore, the traveling speed of the coating particle group lump 36 decreases, and the arrival at the coating surface W is delayed. By the time the paint reaches the painted surface W, mixing with the atmosphere is sufficiently performed, and atomization of the paint particles is further promoted.
The paint sprayed from the spray holes 14 is atomized to about 40 μm and reaches the paint surface W. Since the paint when reaching the painted surface W has a low flow velocity, it does not bounce off the painted surface W and adheres to the painted surface W. In addition, since there is no air for atomization, there is no rebound of air on the painted surface W, and the paint particles can be suitably attached to the painted surface W.

In the above embodiment, the case where the energization signal pattern generated by the controller 28 is a periodic pattern in which the ON potential that continues for 1 ms and the OFF potential that continues for 1 ms is repeated has been described, but the energization signal pattern is not limited thereto. .
In the coating apparatus of the present invention, it is sufficient that the time for which the injection holes are continuously opened, that is, the time for which the ON potential continues is shorter than the time for the paint to reach the coating surface W, and the time for which the OFF potential continues is particularly limited. There is no.
For example, a repeating pattern in which the ON potential continues for 1 ms and then the OFF potential continues for 0.5 ms may be used.

In the above embodiment, the valve 16, the armature 18, the electromagnetic coil 22, the ball 32, and the seat 34 are used to open and close the injection hole 14 as driving means for intermittently opening and closing the connection between the injection hole 14 and the paint chamber 4. However, the means for intermittently opening and closing the injection hole 14 is not limited to this.
For example, instead of the above, an electrically driven butterfly valve may be provided on the inlet side of the orifice 12 and the controller 28 may control the butterfly valve to open and close the injection hole 14.

(Second embodiment)
Another coating apparatus 102 of the present invention will be described with reference to FIG. Components identical to those of the first embodiment are denoted by common reference numerals and description thereof is omitted.

FIG. 2 is a view schematically showing the coating apparatus 102 of the present invention.
The case 30 of the coating apparatus 102 includes an injection switch 38. The injection switch 38 is a push button type switch, and transmits an ON potential to the controller 28 when pressed, and an OFF potential when not pressed.
The controller 28 generates an energization signal pattern to be transmitted to the electromagnetic coil 22 based on the first signal input from the injection switch 38 and the second signal that intermittently turns on and off the electromagnetic coil 22. The first signal (signal 1 in FIG. 3) is an ON potential when the injection switch 38 is pressed, and is an OFF potential when the injection switch 38 is not pressed. The second signal (signal 2 in FIG. 3) is a repetition of an ON potential that lasts 1 ms and an OFF potential that lasts 1 ms. The energization signal pattern (signal 3 in FIG. 3) generated from the first signal and the second signal is set to the ON potential only when the first signal is the ON potential and the second signal is also the ON potential. In this case, the potential is OFF. The controller 28 transmits the generated energization signal pattern to the electromagnetic coil 22.

The operation of the painting apparatus 102 will be described.
In a state where the injection switch 38 is not pressed, the energization signal pattern generated by the controller 28 continues the OFF potential, and thus the electromagnetic coil 22 is not energized. Electromagnetic force does not act on the armature 18, and the ball 32 is in contact with the seat 34 by the urging force of the return spring 24. The paint in the paint tank 6 is driven by the pump 10 to be pressurized and fed into the paint chamber 4 of the coating apparatus 102 via the paint supply path 8. Since the ball 32 and the seat 34 are in contact with each other, the connection between the paint chamber 4 and the injection hole 14 is cut off, and the paint flowing into the paint chamber 4 stays in the paint chamber 4 in a pressurized state. To do.

When the injection switch 38 is pressed, the controller 28 repeatedly transmits to the electromagnetic coil 22 an ON potential signal indicating energization start and an OFF potential signal indicating energization release.
While the injection switch 38 is pressed, the energization signal pattern is a repeat of an ON potential that lasts for 1 ms and an OFF potential that continues for 1 ms. The electromagnetic coil 22 is repeatedly energized and not energized, and the armature 18, the valve 16, and the ball 32 are repeatedly moved in the left-right direction in FIG. The connection between the paint chamber 4 and the injection hole 14 repeats the state of communication and the state of interruption, and the injection of the paint from the injection hole 14 is repeated repeatedly. The paint sprayed intermittently from the spray holes 14 is suitably atomized by admixture with the outside air and adheres to the paint surface W.

  When the pressing of the injection switch 38 is released, the energization signal pattern generated by the controller 28 continues the OFF potential, so that the electromagnetic coil 22 is not energized. Electromagnetic force does not act on the armature 18, and the ball 32 and the seat 34 come into contact with each other due to the urging force of the return spring 24. The connection between the paint chamber 4 and the injection hole 14 is cut off, and the paint flowing into the paint chamber 4 stays in the paint chamber 4 in a pressurized state, and the injection of the paint from the injection hole 14 is stopped. .

  In the painting apparatus 102 of the present embodiment, the operator can control the start and end of painting by operating the injection switch 38. The painting operation is performed in an airless manner, and the paint can be adhered to the painting surface W by spraying the paint intermittently.

  In the above embodiment, the push button type switch is used as the injection switch 38. However, instead of the push button type switch, for example, a lever type switch may be used.

(Third embodiment)
Another coating apparatus 302 of the present invention will be described with reference to FIG. Components identical to those of the first embodiment are denoted by common reference numerals and description thereof is omitted.
The case 330 of the coating apparatus 302 has a cylindrical space therein, and the space passes through the orifice 312a and the injection hole 314a on one end surface 306 of the case 330, and the route passes through the orifice 312b and the injection hole 314b. It communicates with the outside through.
A rotating valve 316 (corresponding to an on-off valve) is housed in the case 330 so as to be able to rotate while being in sliding contact with the end surface 306. The rotary valve 316 is a half-moon shaped plate material, and a rotary shaft 318 is integrally connected to the rotation center thereof. The rotary shaft 318 is connected to the motor 324, and the rotary shaft 318 and the rotary valve 316 rotate when the motor 324 rotates. The rotation of the motor 324 is controlled by the controller 328. The controller 328 controls the motor 324 so that the motor 324 rotates once in 2 ms and half in 1 ms.
FIG. 5 is a view showing a VV cross section of FIG. A conduction state between the coating chamber 304 and the orifice 312a and the orifice 312b is controlled by a rotary valve 316. When the rotary valve 316 is in a position to shield the orifice 312a, the connection between the paint chamber 304 and the orifice 312a and the injection hole 314a is cut off, and the paint chamber 304 communicates with the outside via the orifice 312b and the injection hole 314b. To do. When the rotary valve 316 rotates around the rotary shaft 318 and rotates to a position where the rotary valve 316 shields the orifice 312b, the connection between the paint chamber 304 and the orifice 312b and the injection hole 314b is cut off. It communicates with the outside via the injection hole 314a.
A paint chamber 304 is formed by the surface of the rotary shaft 318, the surface of the rotary valve 316, and the inner surface of the case 330. The paint chamber 304 is connected to the paint tank 6 via the paint supply path 8. The paint is pressurized and sent from the paint tank 6 to the paint chamber 304 by the pump 10 provided in the paint supply path 8. The operation of the pump 10 is controlled by a controller 328.

The operation of the painting apparatus 302 will be described.
In response to an instruction from the controller 328, the motor 324 is driven to rotate the rotary shaft 318 and the rotary valve 316.
The controller 328 drives the pump 10. The paint in the paint tank 6 is driven by the pump 10 to be pressurized and fed into the paint chamber 304 of the coating apparatus 302 via the paint supply path 8. As shown in FIG. 5, when the rotary valve 316 is in a position to shield the orifice 312a, the connection between the paint chamber 304 and the orifice 312a and the injection hole 314a is cut off, and the paint chamber 304 has the orifice 312b and the injection hole 314b. Communicate with the outside via. The pressurized paint fed into the paint chamber 304 flows into the orifice 312b and is injected from the injection hole 314b.
The number of rotations of the motor 324 is controlled by the controller 328, and is controlled so as to rotate in 2 ms for one revolution and 1 ms for one half revolution. When the rotary valve 316 rotates about the rotation shaft 318 and rotates to a position where the orifice 312b is shielded over 1 ms, the connection between the paint chamber 304 and the orifice 312b and the injection hole 314b is cut off, and the paint chamber 304 is connected to the orifice 312a and the injection. It communicates with the outside via the hole 314a. The injection of the paint from the injection hole 314b is stopped, and the pressurized paint is injected from the injection hole 314a instead.
When the rotary valve 316 further rotates around the rotary shaft 318 and rotates again to a position where the orifice 312a is shielded over 1 ms, the connection between the paint chamber 304 and the orifice 312a and the injection hole 314a is cut off, and the paint chamber 304 is connected to the orifice 312b. Communicate with the outside via the injection hole 314b. The injection of the paint from the injection hole 314a stops, and instead, the pressurized paint is injected again from the injection hole 314b.

The paint sprayed from each of the spray holes 314a and 314b diffuses and moves toward the paint surface W while being atomized. Since each of the injection holes 314a and 314b has a tapered shape that spreads toward the outlet, the paint moves to the coating surface W while being diffused in a tapered shape even after being injected from each of the injection holes 314a and 314b. To go.
The paint sprayed from the spray holes 314a and 314b diffuses toward the coating surface W, and the contact area with the outside air increases. Before reaching the paint surface W, the paint particles and the outside air are mixed, and the paint particles are atomized.

  The time for the paint to reach the painting surface W from each of the injection holes 314a and 314b is about 10 ms. On the other hand, the time during which the paint is intermittently injected from each of the injection holes 314a and 314b and the paint is continuously injected is 1 ms. The sprayed paint is sufficiently mixed with the outside air by the outside air wrapping around the back, and is atomized to about 40 μm and adheres to the painted surface.

FIG. 6 shows an opening / closing pattern of the injection holes 314a and 314b in the above situation. Pattern 1 in FIG. 6 shows an opening / closing pattern of the injection holes 314a, and pattern 2 shows an opening / closing pattern of the injection holes 314b. Each of the injection holes is repeatedly opened for 1 ms after being opened for 1 ms, and when one of the injection holes is open, the other injection hole is closed.
In such a case, each of the spray holes 314a and 314b of the coating apparatus 302 intermittently sprays the paint, but while one spray hole is closed, the other spray hole is opened to spray the paint, The total amount of paint sprayed from the coating apparatus 302 is a constant amount regardless of time. Since each injection hole compensates for the decrease in the amount of paint due to intermittent injection, it is possible to atomize the paint without reducing the total amount of paint sprayed from the coating apparatus.

(Fourth embodiment)
An outline of another painting apparatus 200 embodied by the present invention is shown in FIG.
The coating apparatus 200 includes paint spraying apparatuses 202a, 202b, 202c, 202d, a holder 222, a robot arm 220, a paint tank 210, a pump 214, a paint supply path 216, and a controller 212.
The coating material injection devices 202a, 202b, 202c, and 202d are the same as the coating device 2 of the first embodiment.
The paint sprayers 202 a, 202 b, 202 c, 202 d have paint chambers (not shown) connected to the paint tank 210 via the paint supply path 216.
The paint supply path 216 is provided with a pump 214. The paint supply path 216 has a branch path downstream from the pump 214, and distributes and supplies the pressurized paint to the paint injection devices 202a, 202b, 202c, and 202d. The operation of the pump 214 is controlled by the controller 212.
The paint sprayers 202a, 202b, 202c, 202d are held by a holder 222. The holder 222 and the paint spraying devices 202a, 202b, 202c, 202d move together. The robot arm 220 holds the holder 222 and maintains the position and angle of the holder 222. The operation of the robot arm 220 is controlled by the controller 212.
Electromagnetic coils (not shown) inside the paint sprayers 202a, 202b, 202c, 202d are controlled by the controller 212. The coating material injection devices 202a, 202b, 202c, and 202d open the injection holes 204a, 204b, 204c, and 204d by energizing the electromagnetic coils. When energization of the electromagnetic coil is stopped, the injection holes 204a, 204b, 204c, and 204d are closed.

The operation of the coating apparatus 200 will be described with reference to FIG.
When the workpiece W1 is fixed on the jig, the coating apparatus 200 starts the coating process.
The controller 212 drives the pump 214 to pressurize the paint in the paint tank 210 and supply it to the paint injection devices 202a, 202b, 202c, 202d. The spray holes 204a, 204b, 204c, 204d of the paint sprayers 202a, 202b, 202c, 202d are all closed, and the supplied paint stays pressurized in the paint sprayers 202a, 202b, 202c, 202d. To do.
The controller 212 drives the robot arm 220 to adjust the position and angle of the paint sprayers 202a, 202b, 202c, 202d held by the holder 222. When the paint spraying devices 202a, 202b, 202c, 202d are held at a position and an angle at which the article W1 can be suitably coated, the controller 212 moves to an electromagnetic coil (not shown) of the paint spraying devices 202a, 202b, 202c, 202d. An energization signal is transmitted, the spray holes 204a, 204b, 204c, and 204d are opened, and the spray of paint from each paint spray device is started.
The controller 212 causes the paint sprayers 202a, 202b, 202c, and 202d to repeatedly perform an operation of continuously opening the spray holes 204a, 204b, 204c, and 204d for 1 ms and an operation of continuously closing the spray holes for 1 ms.
The paint is sprayed intermittently from each of the paint spraying devices 202a, 202b, 202c, and 202d, and is suitably atomized by mixing with the outside air, and after about 10 ms have elapsed since the spraying from each paint spraying device. It adheres to the painted surface of the workpiece W1.
While spraying the paint, the controller 212 appropriately drives the robot arm 220 to set the positions and angles of the paint sprayers 202a, 202b, 202c, 202d held by the holder 222 so that the coating is suitably performed. adjust.
When the coating on the workpiece W1 is completed, the controller 212 closes the spray holes 204a, 204b, 204c, and 204d and stops the spraying of the paint from the paint sprayers 202a, 202b, 202c, and 202d.

The controller 212 can selectively perform opening / closing control of the spray holes 204a, 204b, 204c, and 204d of the paint spraying devices 202a, 202b, 202c, and 202d for each paint spraying device. For example, it is possible to intermittently inject paint from one paint injection device and not to inject paint from another paint injection device. Various paint spray patterns can be realized by selectively opening and closing the spray holes 204a, 204b, 204c, and 204d.
For example, as shown in FIG. 7, when the coated surface of the article W1 is a wide and smooth surface, the paint is intermittently sprayed from all of the paint spraying devices 202a, 202b, 202c, and 202d, and coating is performed with a wide spray pattern. Can do.
As shown in FIG. 8, when the surface to be coated W2 is narrow, the paint is intermittently injected from only one paint injection device (paint injection device 202b in FIG. 8), and the other paint injection is performed. Coating can be performed with a narrow range of spray patterns without spraying paint from the apparatus (paint spray apparatuses 202a, 202c, 202d in FIG. 8). By selectively controlling the spraying of the paint from the paint spraying device as described above, it is possible to prevent the paint from adhering to parts other than the painted surface, and to efficiently paint without wasting the paint. .
As described above, it is possible to perform coating on various coated surfaces using the same coating device, and high quality coating can be achieved by intermittent spraying of paint regardless of spray pattern. Can be realized. By using the coating apparatus 200 of the present embodiment, the productivity of the coating process is dramatically improved.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The figure which shows the outline | summary of the coating apparatus 2 (1st Example). The figure which shows the outline | summary of the coating apparatus 102 (2nd Example). The figure which shows a signal pattern (2nd Example). The figure which shows the outline | summary of the coating apparatus 302 (3rd Example). The figure which shows the outline | summary of an injection hole opening / closing mechanism (3rd Example). The figure which shows an opening-and-closing pattern (3rd Example). The figure which shows the outline | summary of the coating apparatus 200 (4th Example). The figure which shows the operation example of the coating device 200 (4th Example).

Explanation of symbols

2 ... Painting device 4 ... Paint chamber 6 ... Paint tank 8 ... Paint supply path 10 ... Pump 12 ... Orifice 14 ... Injection hole 16 ... Valve 18 ... Armature 20 ... Stopper 22 ... Electromagnetic coil 24 ... Return spring 28 ... Controller 30 ... Case 32 ... Ball 34 ... Sheet 36 ... Paint particle cluster 38 ... Spray switch 102... Coating device 200... Coating device 202 a, 202 b, 202 c, 202 d... Paint spray device 204 a, 204 b, 204 c, 204 d. 214 ... Pump 216 ... Paint supply path 220 ... Robot arm 222 ... Holder 302 ... Coating device 304 ... Paint chamber 306 ... End 312a, 312b ... orifice 314a, 314b ... injection holes 316 ... rotary valve 318 ... rotating shaft 324 ... motor 328 ... controller 330 ... Case

Claims (5)

An injection hole for injecting pressurized paint;
An on-off valve for opening and closing the injection hole;
It has a drive device that drives the on-off valve to open and close the injection hole intermittently,
A coating apparatus characterized in that the time for which the spray holes are continuously opened is adjusted to be equal to or less than the time until the paint sprayed from the spray holes reaches the coating surface.   2. The coating apparatus according to claim 1, further comprising a control device for driving the on-off valve to intermittently open and close the injection hole from when the coating start signal is input to when the coating end signal is input.   A coating apparatus in which a plurality of coating apparatuses according to claim 1 are arranged in parallel in accordance with the expansion of the painted surface. From the start of painting to the end of painting, it is a method of painting by spraying pressurized paint intermittently from the injection hole,
A coating method characterized in that the time for which the paint is continuously sprayed is equal to or shorter than the time until the paint sprayed from the spray hole reaches the painted surface.   A coating method comprising: arranging a plurality of coating devices according to claim 1 in parallel, and selecting and driving the coating device corresponding to the spread of the painted surface.

Images