JP5812966B2 - Rotary atomizing coating equipment - Google Patents

Description

  The present invention relates to an improvement in a rotary atomizing coating apparatus of a type in which paint is sprayed by a rotary atomizing head.

  A rotary atomizing coating apparatus including a rotary atomizing head has been widely used in practice (for example, see Patent Document 1 (FIG. 2)).

  FIG. 6 is a diagram for explaining the basic configuration of a conventional rotary atomizing coating apparatus. The rotary atomizing coating apparatus 100 includes a rotary shaft 101 and a rotary atomizing head 102 attached to the tip of the rotary shaft 101. And a paint supply passage 103 for supplying paint to the rotary atomizing head 102, a paint outflow hole 104 formed in the rotary atomizing head 102 for allowing the paint to flow out to the front surface, and the rotary atomizing head 102. It comprises a shaping air hole 105 for ejecting shaping air.

  The coating material supplied to the front surface from the coating material outflow hole 104 is discharged from the outer edge of the rotary atomizing head 102 under a centrifugal force, and is shaped with shaping air. As a result, the paint is sprayed forward while drawing a parabola as shown by the arrow (1). However, the particle size of the paint atomized by centrifugal action varies. Among them, the paint having a large particle size flies as shown by the arrow (2) against the shaping air. As a result, a paint having a large particle size is not suitable for an object to be coated. Coating efficiency (coating efficiency) decreases. In order to reduce the coating cost, improvement in coating efficiency is required.

JP-A-9-248495

  This invention makes it a subject to provide the rotary atomization type coating device which can improve coating efficiency.

The invention according to claim 1 is a rotary atomizing coating apparatus comprising a rotary atomizing head that radiates and radiates paint supplied from a paint supply path with centrifugal force.
A paint outflow hole for allowing the paint from the paint supply path to flow out from the back surface to the front surface, and an inner creeping surface that imparts a centrifugal force to the paint that is formed on the front surface and flows out of the paint outflow hole. An inner shaping air ejection hole that ejects shaping air that shapes the shape of the paint discharged from the outer edge of the inner creepage surface, an outer creepage surface that is provided so as to surround the outer edge of the inner creepage surface and receives the paint discharged from the outer edge; An outer shaping air ejection hole is further provided outside the outer creepage surface.

  The invention according to claim 2 is characterized in that the outer edge of the inner creepage is in front of the inner edge of the outer creepage and the outer edge of the inner creepage overlaps with the inner edge of the outer creepage. The front refers to the front side of the rotary atomizing head.

In the first aspect of the present invention, the paint outflow hole, the inner creepage surface, the inner shaping air ejection hole, and the outer creepage surface are arranged in this order from the rotation center to the radially outward side. The paint having a relatively small particle diameter is discharged from the outer edge of the inner creeping surface, and then shaped by the air flow from the inner shaping air ejection hole and sprayed onto the object to be coated. The paint having a relatively large particle size is discharged from the outer edge of the inner creeping surface and then moves to the outer creeping surface. Centrifugal force is applied again on the outer creeping surface and sprayed from the outer edge of the outer creeping surface to the object to be coated. In addition, since the large particle size that could not be sprayed to the coating object with the inside shaping air is further atomized on the outer creeping surface and sprayed forward, all the particle sizes of the paint provided to the coating object are the same. become.
That is, according to the present invention, all the particle diameters of the paint can be made equal, and all of the paint can be applied to the object to be coated, so that the coating efficiency can be greatly improved.

  In addition, in the invention according to claim 1, since the outer shaping air ejection hole is further provided outside the outer creeping surface, the paint discharged from the outer edge of the outer creeping surface by the air flow from the outer shaping air ejection hole is provided. The shape can be adjusted.

In the invention according to claim 2, the outer edge of the inner creeping surface is in front of the inner edge of the outer creeping surface, and the outer edge of the inner creeping surface overlaps with the inner edge of the outer creeping surface.
In the vicinity of the inner shaping air ejection hole, a region where a negative pressure occurs due to the influence (pressure difference) of the air ejection occurs. According to the present invention, since the outer edge of the inner creepage and the inner edge of the outer creepage overlap, even if a part of the paint away from the outer edge of the inner creepage is drawn into the negative pressure region, the paint It hits. As a result, there is no concern that the paint flows back to the inner shaping air ejection hole, and contamination of the rotary atomizing coating apparatus can be avoided.

It is principal part sectional drawing of the rotary atomization type coating apparatus which concerns on this invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1 (a front view of a rotary atomizing head). FIG. 3 is an enlarged view of part 3 of FIG. 1. It is operation | movement explanatory drawing of a rotary atomization type coating device. It is a figure which shows the example of a change of a rotary atomization type coating device. It is a figure explaining the basic composition of the conventional rotary atomization type coating device.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

  As shown in FIG. 1, the rotary atomizing coating apparatus 10 includes a cylindrical gun body 11, a rotary atomizing head 20 that is rotatably disposed at the front center of the gun body 11, and the rotary atomization. The paint supply path 13 for supplying paint to the back surface 21 of the head 20 is a basic constituent member. The gun body 11 and the paint supply path 13 are non-rotating members, and the rotary atomizing head 20 is a rotating member.

  The rotary atomizing head 20 is provided with a paint outflow hole 23 penetrating from the back surface 21 to the front surface 22, and a cup-shaped inner surface 24 is formed on the front surface 22 so as to surround the paint outflow hole 23. An inner shaping air ejection hole 26 penetrating from the back surface 21 to the front surface 22 is provided along the outer edge 24a, and a large-diameter cup-shaped outer creeping surface 27 is formed so as to surround the inner shaping air ejection hole 26. The outer creeping surface 27 is partially connected to the inner creeping surface 24 by a rib (small bridge) or the like.

By providing the inner shaping air ejection hole 26 to be inclined in the direction opposite to the rotation direction of the bell cup, the collision energy between the paint sprayed from the outer edge 24a of the inner creepage surface 24 and the inner shaping air is increased, and the paint is atomized. Efficiency can be improved.
In addition, a fine guide groove 28 is provided on the outer edge 24 a of the inner creepage surface 24, and a fine guide groove 29 is provided on the outer edge 27 a of the outer creepage surface 27. These guide grooves 28 and 29 play a role such as the role of miniaturizing the paint.

  Further, the gun body 11 is provided with a first air passage 31 for supplying air to the inner shaping air ejection hole 26, and an outer shaping air ejection hole 32 is provided at a portion surrounding the outer edge 27a of the outer creeping surface 27. A second air passage 33 for supplying air to the outer shaping air ejection hole 32 is provided.

  The front view of the rotary atomizing head 20 will be described with reference to FIG. 2. The rotary atomizing head 20 has a paint outflow hole 23, an inner creepage surface 24, an inner shaping air ejection hole 26, an outer side. The creeping surfaces 27 are arranged in this order.

  As shown in FIG. 3, the outer edge 24 a of the inner creepage surface 24 overlaps the inner edge 27 b of the outer creepage surface 27 by δ. More precisely, the outer diameter of the inner creepage surface 24 is obtained by adding 2 · δ (double δ) to the inner diameter of the outer creepage surface 27.

  In the vicinity of the inner shaping air ejection hole 26, a region where a negative pressure occurs due to the influence (pressure difference) of the air ejection occurs. According to the present invention, since the outer edge 24a of the inner creepage surface 24 and the inner edge 27b of the outer creepage surface 27 overlap, even if a part of the paint away from the outer edge 24a of the inner creepage surface 24 is drawn into the negative pressure region, The paint hits the inner edge 27b of the outer creepage surface 27 as indicated by an arrow (3). As a result, there is no concern that the paint flows backward to the inner shaping air ejection hole 26, and contamination of the rotary atomizing coating apparatus can be avoided.

Next, the operation of the rotary atomizing coating apparatus having the above configuration will be described.
As shown in FIG. 4A, in principle, the paint flowing out from the paint outflow hole 23 is discharged from the outer edge 24a of the inner creepage surface 24 and then shaped by the air flow from the inner shaping air ejection hole 26. Injected onto the workpiece.

  As shown in FIG. 4B, the paint having a large particle size out of the paint flowing along the inner creeping surface 24 breaks through the air from the inner shaping air ejection hole 26 and reaches the outer creeping surface 27. The paint is applied with centrifugal force on the outer creeping surface 27 and is sprayed from the outer edge 27a of the outer creeping surface 27 to the object to be coated. In addition, since the large particle size that could not be sprayed to the coating object with the inside shaping air is further atomized on the outer creeping surface and sprayed forward, all the particle sizes of the paint provided to the coating object are the same. become.

  By overlapping FIGS. 4 (a) and (b), all the particle diameters of the paint can be made equal, and all of the paint can be used for coating the object to be coated, and the coating efficiency can be greatly improved. .

  The shape of the paint sprayed from the outer edge 27a of the outer creeping surface 27 can be adjusted by ejecting the shaping air from the outer shaping air ejection hole 32.

Further, even when the outer shaping air ejection hole 32 is provided, the second air passage 33 can be omitted. A specific example will be described next.
As shown in FIG. 5, only the first air passage 31 is provided in the gun body 11. The air supplied through the first air passage 31 is divided into two parts, one is supplied to the inner shaping air ejection hole 26, and the other is ejected from the outer shaping air through the gap 36 between the back surface of the rotary atomizing head 20 and the gun body 11. It ejects from the hole 32.

  FIG. 5 simplifies the structure of the gun body 11 and can reduce the cost of the rotary atomizing coating apparatus 10. However, the distribution (ratio) between the amount of air ejected from the inner shaping air ejection hole 26 and the amount of air ejected from the outer shaping air ejection hole 32 is fixed.

  In this regard, FIG. 4 has an advantage that the distribution of the amount of air ejected from the inner shaping air ejection hole 26 and the distribution of the amount of air ejected from the outer shaping air ejection hole 32 can be arbitrarily changed.

  The present invention can be applied to a rotary atomizing coating apparatus including a rotary atomizing head.

  DESCRIPTION OF SYMBOLS 10 ... Rotary atomization type coating device, 11 ... Gun body, 13 ... Paint supply path, 20 ... Rotary atomization head, 21 ... Back surface of rotary atomization head, 22 ... Front surface of rotary atomization head, 23 ... Paint outflow hole 24 ... Inner creepage, 24a ... Outer edge of inner creepage, 26 ... Inner shaping air ejection hole, 27 ... Outer creepage, 27a ... Outer edge of outer creepage, 27b ... Inner edge of outer creepage, 32 ... Outer shaping air ejection hole.

Claims (2)

In the rotary atomizing coating apparatus provided with a rotary atomizing head that atomizes and radiates the paint supplied from the paint supply path with centrifugal force,
A paint outflow hole for allowing the paint from the paint supply path to flow out from the back surface to the front surface, and an inner creeping surface that imparts a centrifugal force to the paint that is formed on the front surface and flows out of the paint outflow hole. An inner shaping air ejection hole that ejects shaping air that shapes the shape of the paint discharged from the outer edge of the inner creepage surface, an outer creepage surface that is provided so as to surround the outer edge of the inner creepage surface and receives the paint discharged from the outer edge; A rotary atomizing coating apparatus, further comprising an outer shaping air ejection hole outside the outer creepage surface.   2. The rotary atomizing coating apparatus according to claim 1, wherein an outer edge of the inner creepage is in front of an inner edge of the outer creepage, and an outer edge of the inner creepage overlaps with an inner edge of the outer creepage. .

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