JP2007021328A - Coater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To expand and narrow a coating pattern by an air stream jetted from the rear side to surround a rotary spraying head for increasing the degree of freedom in the adjustment. <P>SOLUTION: A coater (1) is provided with an air stream-jetting direction control mechanism (8) which adjusts the air stream-jetting direction jetted from the rear side so as to surround the rotary spraying head (5) arranged at a machine (2) tip to set the coating pattern (P). In the coater (1), the air stream-jetting direction control mechanism (8) is formed integrally to an annular slit (7), which turns a shaping air spout formed at the machine (2) tip along a rear of a margin of the rotary spraying head (5). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coating machine provided with an air flow ejection direction control mechanism that adjusts the ejection direction of an air flow ejected from the back side so as to surround a rotary atomizing head and arranges a coating pattern.

The rotary atomizing electrostatic coating machine sprays shaping air from the back side of the rotary atomizing head so as to surround the rotary atomizing head, thereby adjusting the coating pattern when the paint adheres to the surface of the object and scattering of paint particles. And the coating efficiency is improved.
If the supply pressure of the shaping air is adjusted as necessary and the supply amount of paint is increased, it is necessary to maintain the coating pattern for thick coating purposes. In the case where the coating pattern is expanded while the coating film thickness is maintained while being set high, the shaping air supply pressure is set relatively low.

However, since the coating pattern cannot be adjusted sufficiently by adjusting the supply pressure of the shaping air, recently, the coating pattern has been devised by devising the flow of air formed around the rotary atomizing head. A painting machine to prepare is proposed.
JP 2005-131590 A

FIG. 8 shows such a conventional coating machine 61, in which a substantially cylindrical main air flow F ₁ is formed around the rotary atomizing head 63 disposed at the tip of the machine body 62, and the peripheral surface of the machine body 62 is formed. The auxiliary air flow F ₂ is formed outside the main air flow F ₁ by covering the adapter 64, and the induced flow generated by the main air flow F _{1 is} controlled by variably controlling the jet direction of the sub air flow F _2. The paint pattern is arranged by offsetting.
However, even if the ejection direction of the auxiliary air flow F ₂ is controlled, it is only possible to offset the induced flow caused by the main air flow F ₁ and improve the coating efficiency, and the coating pattern is positively controlled. It is not possible.
Therefore, control of the coating pattern are forced to resort to pressure control of the primary air flow F _1, it is not different from the adjustment essentially by the conventional shaping air.

  Therefore, the present invention has a technical problem of widening the degree of freedom in adjusting the coating pattern by the air flow blown from the back side so as to surround the rotary atomizing head.

  In order to solve this problem, the present invention adjusts the jet direction of the air flow jetted from the back side so as to surround the rotary atomizing head arranged at the front end of the airframe, and adjusts the paint pattern to make the air flow jet direction In the coating machine provided with the control mechanism, the air flow ejection direction control mechanism is integrally formed in an annular slit that is a shaping air ejection port formed at the front end of the machine body along the back surface of the peripheral portion of the rotary atomizing head. It is characterized by that.

  In the present invention, the term “paint” refers to a concept that includes a liquid coating material that forms a liquid film on the surface of an article to be coated, such as an oil coating agent and an adhesive, in addition to a so-called paint. The concept includes spraying such a liquid coating material to form a liquid film on the surface of the object to be coated.

  According to the present invention, the air flow ejection direction control mechanism is integrally formed with the annular slit serving as the shaping air ejection port formed at the front end of the airframe along the back surface of the peripheral portion of the rotary atomizing head. The shaping air ejected from the annular slit is controlled by an air flow ejection direction control mechanism formed in the annular slit, and is directly sprayed on the paint particles sprayed from the peripheral portion of the rotary atomizing head to generate the sprayed air. Since the area is expanded or narrowed, there is an excellent effect that it is possible to control the coating pattern applied to the surface of the object to be coated.

In this case, if the air pressure supplied to the annular slit is increased or decreased by the air pressure control means as in claim 2, the air speed of the shaping air increases when the air pressure is high. As a result, the coating pattern becomes smaller if the other conditions are equal, and the coating pattern becomes larger if the air pressure is lowered.
As in claim 3, as an air flow ejection direction control mechanism, an inner ring and an outer ring that are relatively movable in the rotational axis direction of the rotary atomizing head are arranged with a predetermined clearance, and the annular ring is interposed between them. A slit and an annular chamber communicating with the annular slit are formed, an outward guide surface is formed at the annular slit opening of the inner ring to eject shaping air outward, and at the annular slit opening of the outer ring If an inward guide surface that blows shaping air inward is formed, the shaping air is projected by projecting the inner ring side against the neutral direction of shaping air that is blown when the inner ring and outer ring are aligned. Can be ejected outward along its guide surface. It can be sprayed the shaping air by protruding the side inwardly along the guide surface.

Further, as in the fourth and fifth aspects, a plurality of sets of air nozzles for injecting air from different angles with respect to the circumferential direction are formed in the annular chamber, and each of the sets of air nozzles is selectively used. Alternatively, if air is supplied at the same time, the flow velocity and direction of the air flow rotating in the annular chamber can be changed, and thereby, the jetting direction of the shaping air can be variably controlled with respect to the rotation direction of the rotary atomizing head.
Here, as in claim 6, an air nozzle for forming a forward direction rotating flow inclined in the rotation direction of the rotary atomizing head and an air nozzle for forming a reverse direction rotating flow inclined in the anti-rotation direction are formed. If air is supplied to each air nozzle selectively or simultaneously, the ejection direction of the shaping air can be variably controlled with respect to the rotation direction of the rotary atomizing head.
That is, if air is supplied from the air nozzle for forming the forward direction swirl flow, a forward swirl flow is formed in the annular chamber, and a spiral flow rotating in the forward direction is ejected as shaping air from the annular slit. Shaping air can be formed along the flow of paint particles.
Further, if air is supplied from the air nozzle for forming a reverse swirl flow, a reverse swirl flow is formed in the annular chamber, and a spiral rotating in the reverse direction with respect to the rotation direction of the rotary atomizing head from the annular slit. Since the flow is ejected as shaping air, it is possible to form shaping air that disturbs the flow of the paint particles.
Furthermore, if the air is supplied from both sides, the swirl flow is canceled and the inside of the annular chamber becomes positive pressure, so that shaping air without twisting can be formed.

  In this example, in order to achieve the purpose of expanding or narrowing the coating pattern by the air flow ejected from the back side so as to surround the rotary atomizing head, the ejection direction of the shaping air is variably controlled. did.

  FIG. 1 is a cross-sectional view showing the internal structure of a coating machine according to the present invention, FIGS. 2 and 3 are explanatory views showing its movement, FIG. 4 is an explanatory view showing main parts, and FIG. 5 is a relationship between a jetting direction and a coating pattern. FIG. 6 is an explanatory diagram showing the relationship between the swirl flow and the ejection direction, and FIG. 7 is an explanatory diagram showing another example.

  The coating machine 1 shown in FIG. 1 has a rotary atomizing head 5 attached to the tip of a tubular rotary shaft 4 of an air motor 3 incorporated in the machine body 2 and rotates via a feed tube 6 communicated with the tubular rotary shaft 4. The coating material supplied to the atomizing head 5 is sprayed from the atomizing edge 5a formed in the peripheral part by centrifugal force.

  An annular slit 7 serving as a spout for shaping air (air flow) ejected from the back side of the spray region S of paint particles from the rotary atomizing head 5 to the article W to be coated is provided at the tip of the body 2. Coating is performed when the paint adheres to the surface of the object to be coated by adjusting the jet direction of the air flow that forms the shaping air F in the annular slit 7 formed along the back surface of the peripheral portion of the rotary atomizing head 5. An air flow ejection direction control mechanism 8 for adjusting the pattern P is integrally formed.

The air flow ejection direction control mechanism 8 includes an inner ring 9A and an outer ring 9B that are relatively movable in the direction of the rotation axis of the rotary atomizing head 5, with a predetermined clearance therebetween. An annular chamber 10 communicating with the slit 7 is formed.
An outward guide surface 11A is formed at the annular slit opening of the inner ring 9A so that the shaping air F is ejected outward when the inner ring 9A protrudes from the outer ring 9B.
In addition, an inward guide surface 11B is formed in the annular slit opening of the outer ring 9B so that the shaping air F is ejected inward when the outer ring 9B protrudes from the inner ring 9A.

In this example, a position adjusting mechanism 12 for moving the outer ring 9B with respect to the inner ring 9A fixed to the machine body 2 is formed.
In the position adjusting mechanism 12, a piston flange 13 formed on the outer peripheral surface of the inner ring 9A is housed in a concave groove 14 formed on the inner peripheral surface of the outer flange 9B to form a double-acting cylinder 15, and the concave The groove 14 is provided with a spring 16 for maintaining the outer ring 9B in a neutral position with respect to the piston flange 13 and is provided with an air drive system 17 for selectively supplying drive air to both sides of the piston flange 13. .

When drive air is not supplied from the air drive system 17, the outer ring 9B is positioned neutral with respect to the inner ring 9A, and the shaping air F is ejected in a neutral direction (for example, parallel to the rotation axis direction).
Then, when driving air is supplied to the front side of the piston flange 13, the outer ring 9B protrudes to the front end side, so that the shaping air F is ejected inward along the inward guide surface 11B.
Further, when driving air is supplied to the back side of the piston flange 13, the outer ring 9B is retracted and the inner ring 9A is protruded to the tip side, so that the shaping air F is directed outward along the outward guide surface 11A. Erupted.
The position of the outer ring 9B is controlled by controlling the pressure of the driving air supplied from the air drive system 17 to the front side and the back side of the piston flange 13, and is formed between the inner ring 9A and the inner ring 9A. The opening area of the annular slit 7 can be continuously changed.

  The annular chamber 10 is formed with a plurality of air nozzles 21A and 21B for injecting air from different angles with respect to the circumferential direction, and selectively or simultaneously supplies air to each air nozzle 21A and 21B. Thus, the air supply system 22 that variably controls the ejection direction of the shaping air F with respect to the rotation direction of the rotary atomizing head 5 is connected.

  In this example, a positive direction rotating flow forming air nozzle 21A that injects air into the annular chamber 10 in the rotational direction R of the rotary atomizing head 5, and air is injected into the annular chamber 10 in the counter-rotating direction. The reverse direction swirl forming air nozzle 21B is formed.

Then, if air is supplied from the air supply system 22 from the air nozzle 21A for forming a forward direction swirl flow, a forward swirl flow is formed in the annular chamber 10, and a spiral flow rotating in the forward direction from the annular slit 7 is generated. Since the wind force of the shaping air F acts in the same direction as the centrifugal force of the rotary atomizing head 5 which is ejected as the shaping air F and acts on the paint particles, the paint particles are blown further away and the coating pattern P is enlarged. The Rukoto.
Further, if air is supplied from the reverse direction swirl forming air nozzle 21 </ b> B, a reverse swirl flow is formed in the annular chamber 10, and the reverse rotation direction R of the rotary atomizing head 5 is reversed from the annular slit 7. Since the spiral flow in the direction is ejected as shaping air F and the wind force of the shaping air F acts in the opposite direction to the centrifugal force of the rotary atomizing head 5 acting on the paint particles, the centrifugal force is canceled and the paint particles are far away. The coating pattern P is reduced in diameter without flying to the end.
Further, if air is supplied from both the air nozzles 21A and 21B, the rotational flow is canceled and the inside of the annular chamber 10 becomes a positive pressure, so that the shaping air F without twisting is ejected.
Furthermore, the air supply system 22 increases or decreases the air pressure supplied to both the air nozzles 21A and 21B by an air pressure control means such as an electropneumatic regulator, an air throttle valve, and an air regulator (none of which are shown). The painting pattern can be finely adjusted by increasing or decreasing the air pressure in the annular chamber 10.

The above is one configuration example of the present invention, and the operation thereof will be described next.
If painting is performed without supplying air from the air drive system 17, the outer ring 9B is positioned neutral with respect to the inner ring 9A, and neither of the guide surfaces 11A and 11B is exposed. In parallel, the shaping air F is ejected (see FIG. 5A).
Here, for example, when it becomes necessary to narrow down the coating pattern due to a narrow coating width on the surface of the object to be coated, the supply amount of the paint is reduced, and at the same time, air is supplied from the air drive system 17 to the front side of the piston flange 13. Since the outer ring 9B protrudes to the tip side, the inward guide surface 11B is exposed and the shaping air F is ejected inward (see FIG. 5B).
As a result, the spray area S of the paint is narrowed down by the shaping air F, and the coating pattern P can be reliably reduced while maintaining the film thickness constant.
In addition, if the protrusion amount of the outer ring 9B is increased, the opening area is enlarged, so that the air velocity of the shaping air F can be reduced if the supply pressure is the same, and if the protrusion amount is reduced, the opening area becomes narrower. With the supply pressure, the wind speed can be increased.

In addition, when it becomes necessary to widen the coating pattern by widening the surface of the object to be coated, air is supplied from the air drive system 17 to the back side of the piston flange 13 at the same time as the amount of paint supplied is increased. In this case, the outer ring 9B is retracted and the inner ring 9A is relatively projected, so that the outward guide surface 11B is exposed and the shaping air F is ejected outward (see FIG. 5C).
As a result, the spray angle of the shaping air F that regulates the paint particles sprayed from the rotary atomizing head 5 is expanded, so that the spray region S regulated by the shaping air F is expanded and the coating is performed while the film thickness is kept constant. The pattern P can be expanded.
If the protrusion amount of the inner ring 9A is increased, the opening area is expanded, so that the air velocity of the shaping air F can be reduced if the supply pressure is the same, and if the protrusion amount is decreased, the opening area becomes narrower. With the supply pressure, the wind speed can be increased.

  Furthermore, in this example, since the direction of the swirl flow formed in the annular chamber 10 can be variably controlled, the shaping air F is ejected as a spiral flow in the forward and reverse directions with respect to the rotation direction in each case described above. Thus, the size of the coating pattern P can be finely adjusted.

That is, if air is supplied from the positive direction rotating flow forming air nozzle 21 </ b> A, a positive direction rotating flow equal to the rotation direction of the rotary atomizing head 5 is formed in the annular chamber 10, and the positive direction from the annular slit 7 is formed. Since the rotating spiral flow is ejected as the shaping air F, an air flow along the flow of the paint particles is formed (see FIG. 6A).
As a result, since the wind force of the shaping air F acts in the same direction as the centrifugal force of the rotary atomizing head 5 acting on the paint particles, the paint particles are blown farther and the paint pattern P is expanded.

Further, if air is supplied from the reverse direction swirl flow forming air nozzle 21 </ b> B, a reverse direction swirl is formed in the annular chamber 10, and the direction opposite to the rotational direction of the rotary atomizing head 5 is formed from the annular slit 7. Is ejected as the shaping air F, an air flow in the direction opposite to the flow of the paint particles is formed (see FIG. 6B).
As a result, the wind force of the shaping air F acts in a direction opposite to the centrifugal force of the rotary atomizing head 5 acting on the paint particles, so that the centrifugal force is canceled and the paint particles do not fly far and the coating pattern P is reduced in diameter. Will be.

Further, if air is supplied from both the air nozzles 21A and 21B, the rotational flow is canceled and the inside of the annular chamber 10 becomes positive pressure, so that the shaping air F is ejected without forming a spiral flow (FIG. 6 ( c)).
As a result, the coating pattern P has an intermediate size when the spiral flow in the same direction as the centrifugal force of the rotary atomizing head 5 is formed and when the spiral flow in the opposite direction is formed.

Furthermore, in this example, the air pressure ejected from the air nozzles 21A and 21B by the air supply system 22 can be adjusted.
At this time, by adjusting the wind speed ejected from the air nozzles 21A and 21B by the air supply system 22, the wind speed and direction of the whirling flow in the annular chamber 10 can be freely adjusted.
Further, if the air is ejected from each of the air nozzles 21A and 21B at the same wind speed, only the internal pressure of the annular chamber 10 can be adjusted with the rotating flow in the annular chamber 10 stopped.
In either case, if the internal pressure of the annular chamber 10 is high, the wind speed of the shaping air F ejected from the annular slit 7 increases, and the influence of the shaping air F on the coating pattern P increases. When the pattern P becomes smaller and the air pressure is lowered, the coating pattern P becomes larger.

In the above description, the case in which the ejection direction of the shaping air F is variably controlled inward and outward and the direction in which the shaping air F is ejected is variably controlled is described. It may be a case where variable control is performed only in the direction.
Moreover, although the case where the forward direction swirl flow forming air nozzle 21A and the reverse swirl flow forming air nozzle 21B that change the direction of the swirl flow are arranged in the annular chamber 10 has been described, the angle in the same direction as shown in FIG. A plurality of sets of air nozzles 22 </ b> A and 22 </ b> B may be formed.
In this case, the speed can be changed without changing the direction of the swirl flow, and as a result, the size of the coating pattern P can be finely adjusted according to the speed.
Furthermore, although the case where the inner ring 9A is fixed and the outer ring 9B is arranged so as to be able to advance and retract has been described, even in the case where the outer ring 9B is fixed and the inner ring 9A is arranged so as to be able to advance and retract, both are placed in opposite directions. It may be a case of advancing and retreating.

  As described above, the present invention can be applied to a coating machine that controls the coating pattern by shaping air when the paint particles sprayed from the rotary atomizing head adhere to the surface of the object to be coated.

Sectional drawing which shows the internal structure of the coating machine which concerns on this invention. Explanatory drawing which shows the movement. Explanatory drawing which shows the movement. Explanatory drawing which shows the principal part. Explanatory drawing which shows the relationship between an ejection direction and a coating pattern. Explanatory drawing which shows the relationship between a whirling flow and the ejection direction. Explanatory drawing which shows another example. Explanatory drawing which shows the conventional coating machine.

Explanation of symbols

1 Coating machine 2 Airframe 5 Rotating atomizing head W Workpiece W
S Spray area 7 Annular slit P Coating pattern 8 Air flow ejection direction control mechanism 9A Inner ring 9B Outer ring 10 Annular chamber 11A Outward guide surface 11B Inward guide surface 12 Position adjustment mechanism 21A Forward direction flow forming air nozzle 21B Reverse direction rotation Air nozzle for flow formation

Claims (6)

In a coating machine equipped with an air flow jet direction control mechanism that adjusts the jet direction of the air flow jetted from the back side so as to surround the rotary atomizing head arranged at the tip of the machine body,
A coating machine, wherein the air flow ejection direction control mechanism is integrally formed in an annular slit serving as a shaping air ejection port formed at the front end of the machine body along the back surface of the peripheral portion of the rotary atomizing head.   The coating machine of Claim 1 provided with the air pressure control means which controls the air pressure supplied to the said annular slit. As the air flow ejection direction control mechanism, an inner ring and an outer ring that are relatively movable in the rotational axis direction of the rotary atomizing head are arranged with a predetermined clearance, and communicated with the annular slit and the annular slit therebetween. An annular chamber is formed,
The annular slit opening of the inner ring is formed with an outward guide surface that ejects shaping air outward when the inner ring protrudes, and the outer ring protrudes from the annular slit opening of the outer ring. The coating machine according to claim 1, wherein an inward guide surface is formed to cause shaping air to be ejected inward.   The annular chamber is provided with a plurality of air nozzles for injecting air from different angles with respect to the circumferential direction thereof, and the air is selectively or simultaneously supplied to the air nozzles of the respective groups to rotate the jetting direction of the shaping air. The coating machine of Claim 3 provided with the air supply system variably controlled with respect to the rotation direction of the atomization head.   As the air flow ejection direction control mechanism, a plurality of sets of air nozzles for injecting air from different angles with respect to the circumferential direction are provided in the annular chamber having the annular slit, and each set of air nozzles is selectively or simultaneously provided. The coating machine of Claim 1 provided with the air supply system which variably controls the ejection direction of shaping air with respect to the rotation direction of a rotary atomizing head by supplying air. The air nozzle forms a forward rotation air nozzle for injecting air into the annular chamber in the direction of rotation of the rotary atomizing head, and a reverse rotation in which air is injected into the annular chamber in the counter rotation direction. The coating machine according to claim 4 or 5, comprising a flow forming air nozzle.

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