JP2017047348A - Rotary atomization head type coating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity during the coating work by preventing a cleaning fluid or a coat from remaining in a cleaning fluid/coat remaining space to simplify the cleaning work for the rotary atomization head.SOLUTION: A rotary atomization head 18 is configured by including a cleaning fluid reservoir 23 positioned between a cleaning fluid partition wall 19F and a coating partition wall 19G to reserve a cleaning fluid supplied from a feed tube 6, an outer peripheral surface cleaning passage 25 that makes the cleaning fluid supplied from a feed tube 6 to the cleaning fluid reservoir 23 flow out to the outer peripheral surface 19E of the rotary atomization head body 19, and a cleaning fluid/coat remaining space 26 in a rotary shaft mount hole 19C. In addition to this, the cleaning fluid partition wall 19F of the atomization head body 19 is provided with a cleaning fluid/coat outflow passage 27 that makes the cleaning fluid or the coat having flowed into the cleaning fluid/coat remaining space 26 through a gap between the feed tube 6 and the cleaning fluid partition wall 19F of the atomization head body 19 flow out toward the outer peripheral surface cleaning passage 25.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary atomizing head type coating machine that sprays paint particles from, for example, a rotary atomizing head toward an object to be coated.

  In general, when painting automobile bodies, furniture, electrical appliances, etc., a rotary atomizing head type coating machine is used which has good paint application efficiency and finish. The rotary atomizing head type coating machine supplies an air motor that uses compressed air as a power source, a hollow rotating shaft that is rotatably supported by the air motor and has a tip protruding forward from the air motor, and paint or cleaning fluid. The inner cylinder that extends through the rotary shaft to the tip of the rotary shaft and is located at the center of the shaft and that supplies the paint or cleaning fluid, and is positioned on the outer peripheral side of the inner cylinder and recedes from the tip of the inner cylinder A feed tube comprising an outer cylinder that opens to the position and supplies cleaning fluid to and from the inner cylinder, and a cup-shaped body that expands toward the front side, and the tip of the rotating shaft is attached to the rear side And a rotary atomizing head having a coating film thinning surface for spraying the coating material supplied from the feed tube on the front side.

  The rotary atomizing head has a cleaning fluid partition wall protruding radially inward at a position facing the tip end portion of the outer cylinder of the feed tube, a front side of the cleaning fluid partition wall, and a protruding site of the inner cylinder. A paint partition wall protruding radially inward at the enclosed position, a cleaning fluid reservoir positioned between the cleaning fluid partition wall and the paint partition wall and storing cleaning fluid supplied from an outer cylinder of the feed tube; and the feed An outer peripheral surface cleaning passage that is open to the outer peripheral surface of the rotary atomizing head, and the cleaning fluid supplied from the outer cylinder of the tube to the outer peripheral surface of the rotary atomizing head in order to flow the cleaning fluid supplied to the outer peripheral surface of the rotary atomizing head; The cleaning fluid / paint residual space is formed in the rotary shaft mounting hole of the rotary atomizing head between the rear surface of the fluid partition and the tip of the rotary shaft (see, for example, Patent Document 1).

  In this rotary atomizing head type coating machine, when the painting operation is completed, the cleaning fluid is supplied to the cleaning fluid reservoir from between the inner tube and the outer tube of the feed tube with the rotary atomizing head rotated. Thereby, the cleaning fluid supplied to the cleaning fluid reservoir can be discharged to the outer peripheral surface of the rotary atomizing head via the outer peripheral surface cleaning passage, and the paint adhering to the outer peripheral surface of the rotary atomizing head is cleaned. Can do.

JP 2002-168883 A

  Here, when the cleaning fluid or paint is discharged from the feed tube, a part of the scattered cleaning fluid or paint may flow into the cleaning fluid / paint residual space through the gap between the feed tube and the cleaning fluid partition wall. In addition, when cleaning is performed using an external cleaning machine for cleaning the rotary atomizing head or the like from the outside, a part of the cleaning fluid sprayed from the external cleaning machine toward the rotary atomizing head is May flow into paint residual space.

  As described above, in the state where the cleaning fluid / paint remains in the cleaning fluid / paint residual space, the cleaning fluid / paint in the cleaning fluid / paint residual space may become the rotary atomizing head depending on the posture of the rotary atomizing head type coating machine. It flows out through the various passages and outer peripheral surface cleaning passages provided on the outer surface, and is attached to the outer surface of the rotary atomizing head. Then, the cleaning fluid and paint adhering to the outer surface of the rotary atomizing head may be scattered around and adhering to the painted surface when the rotary atomizing head type coating machine is moved by the painting robot. Further, the cleaning fluid or paint remaining in the cleaning fluid / paint residual space may be mixed into the paint supplied as the next color.

  In this case, in order to prevent scattered cleaning fluid or paint from adhering to the painted surface or mixing in a different color paint, remove the rotary atomizing head after each painting operation and disassemble it. There is a problem that the productivity at the time of painting work decreases because it has to be washed.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to clean the rotary atomizing head by preventing the cleaning fluid / paint from remaining in the cleaning fluid / paint residual space. It is intended to provide a rotary atomizing head type coating machine that can improve productivity during painting work by simplifying the above.

  A rotary atomizing head type coating machine according to the present invention includes an air motor using compressed air as a power source, a hollow rotating shaft that is rotatably supported by the air motor and has a tip projecting forward from the air motor, and paint or cleaning fluid. An inner cylinder that passes through the rotary shaft and extends to the tip of the rotary shaft for supply and is positioned at the shaft center and supplies the paint or cleaning fluid, and is positioned on the outer peripheral side of the inner cylinder and the tip of the inner cylinder A feed tube comprising an outer cylinder that opens to a position that is more receded and supplies the cleaning fluid to and from the inner cylinder, and a cup-shaped body that expands toward the front, and the tip of the rotating shaft on the rear And a rotary atomizing head having a coating film thinning surface for spraying the coating material supplied from the feed tube on the front side, and the rotary atomizing head is connected to the feed tube. A cleaning fluid partition protruding inward in the radial direction at a position facing the tip portion of the outer cylinder, and protruding inward in the radial direction at a position in front of the cleaning fluid partition and surrounding the protruding portion of the inner cylinder A paint partition, a cleaning fluid reservoir that is positioned between the cleaning fluid partition and the paint partition and stores the cleaning fluid supplied from the outer tube of the feed tube, and from the outer tube of the feed tube to the cleaning fluid reservoir In order to allow the supplied cleaning fluid to flow out to the outer peripheral surface of the rotary atomizing head, an outer peripheral surface cleaning passage opened in the outer peripheral surface of the rotary atomizing head, a rear surface of the cleaning fluid partition wall, and a tip of the rotating shaft In the rotary atomizing head type coating machine constituted by the cleaning fluid / paint residual space formed in the rotary shaft mounting hole of the rotary atomizing head, the cleaning fluid partition wall of the rotary atomizing head The fee A cleaning fluid / paint outflow passage is provided in which the cleaning fluid or paint flowing into the cleaning fluid / paint residual space through the gap between the tube and the cleaning fluid partition wall flows out toward the outer peripheral surface cleaning passage. .

  According to the present invention, when the painting operation is completed, the rotary atomizing head is rotated at a high speed together with the rotating shaft by the air motor. As a result, the cleaning fluid or paint flowing into the cleaning fluid / paint residual space can flow out toward the outer peripheral surface cleaning passage of the rotary atomizing head by the cleaning fluid / paint outflow passage, and rotate from the outer peripheral surface cleaning passage. It can flow out to the outer peripheral surface side of the atomizing head.

  As a result, even if a part of the cleaning fluid or paint flows into the cleaning fluid / paint residual space, the centrifugal force generated when the rotary atomizing head rotates causes the cleaning fluid or paint to rotate through the cleaning fluid / paint outflow passage. It can be discharged outside the chemical head. As a result, since the cleaning fluid or paint does not remain in the cleaning fluid / paint residual space, the cleaning fluid or paint does not adhere to the outer surface of the rotary atomizing head. Therefore, it is possible to reduce the frequency of the disassembling and cleaning work performed in order to prevent poor painting, and improve the productivity of the painting work.

  Moreover, it is possible to prevent the cleaning fluid or paint from flowing into the air motor by not leaving the cleaning fluid or paint in the cleaning fluid / paint remaining space.

It is sectional drawing which shows the rotary atomizing head type coating machine by the 1st Embodiment of this invention. It is sectional drawing which expands and shows the front side part of the rotary atomization head type coating machine of FIG. It is sectional drawing which expands and shows the III section in FIG. It is sectional drawing which looked at the rotary atomization head etc. from the arrow IV-IV direction of FIG. It is sectional drawing which looked at the front side part of the rotary atomization head type coating machine by 2nd Embodiment from the same position as FIG. It is sectional drawing which looked at the rotary atomization head etc. from the arrow VI-VI direction of FIG. It is sectional drawing which looked at the front side part of the rotary atomization head type coating machine by 3rd Embodiment from the same position as FIG. It is sectional drawing which looked at the front side part of the rotary atomization head type coating machine by 4th Embodiment from the same position as FIG. It is sectional drawing which shows the rotary atomization head type coating machine by 5th Embodiment. It is sectional drawing which looked at the rotary atomization head by a modification from the same position as FIG. It is sectional drawing which looked at the front side part of the rotary atomizing head type coating machine by a reference example from the same position as FIG.

  Hereinafter, a rotary atomizing head type coating machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  1 to 4 show a first embodiment of the present invention. In the first embodiment, a rotary atomizing head type coating machine provided with a rotary atomizing head having a thin coating film thinning surface is described as an example.

  In FIG. 1, a rotary atomizing head type coating machine 1 according to the present embodiment is configured as a direct charging type electrostatic coating machine that directly applies a high voltage to a paint by a high voltage generator (not shown), for example. Has been. The rotary atomizing head type coating machine 1 is attached to the tip of an arm (not shown) of a painting robot, for example. The rotary atomizing head type coating machine 1 includes a housing 2, an air motor 3, a rotary shaft 5, a feed tube 6, and a rotary atomizing head 18 which will be described later.

  The base 2 of the housing 2 is attached to the tip of the arm. The housing 2 is provided with a motor housing portion 2A so as to open to the front end side, and the opening side of the motor housing portion 2A is provided with a female screw portion 2B located on the inner peripheral side expanded one step. It has been. Further, the housing 2 has an insertion hole 2C into which a base end side of a feed tube 6 described later is inserted at a central position (a position of an axis OO of the rotation shaft 5 described later) of the bottom of the motor housing portion 2A. Is provided.

  The air motor 3 is provided coaxially with the axis OO in the motor housing 2 </ b> A of the housing 2. The air motor 3 rotates a rotary shaft 5 and a rotary atomizing head 18 (described later) at a high speed of 3000 to 150,000 rpm, for example, using compressed air as a power source. The air motor 3 is provided in a stepped cylindrical motor case 3A attached to the front side of the housing 2, a turbine 3B which is positioned near the rear side of the motor case 3A and rotatably accommodated, and the motor case 3A. And the air bearing 3 </ b> C that rotatably supports the rotating shaft 5.

  The motor case 3 </ b> A of the air motor 3 is formed as a cylindrical body whose center line is the axis OO of the rotation shaft 5. The motor case 3A includes a large-diameter large-diameter cylinder 3A1 that is inserted into the motor housing portion 2A of the housing 2 and a small-diameter small-diameter cylinder 3A2 that protrudes forward from the tip (front end) of the large-diameter cylinder 3A1. It is formed in a cylindrical shape. A cable attachment hole 3A3 is provided on the rear side of the large diameter cylinder 3A1 so as to face the outer diameter portion of the turbine 3B, and a rotation speed detection cable 3D described later is inserted into the cable attachment hole 3A3. Yes.

  The turbine 3B is configured by an impeller (not shown) formed by connecting a plurality of blades in the circumferential direction. Turbine air (compressed air) supplied from a turbine air supply pipe 28, which will be described later, is sprayed toward the turbine 3B, whereby the turbine 3B rotates the rotary shaft 5 at high speed. The air bearing 3C is attached to the inner peripheral side of the motor case 3A, and rotates through an annular air layer by spraying supplied bearing air (compressed air) toward the outer peripheral surface of the rotary shaft 5. The shaft 5 is rotatably supported.

  Further, the motor case 3A of the air motor 3 is provided with a rotation speed detection cable 3D. The rotational speed detection cable 3D is disposed so as to face the outer diameter portion of the turbine 3B by inserting the distal end portion thereof into the cable attachment hole 3A3 of the motor case 3A. The rotational speed detection cable 3D detects the rotational speed of the turbine 3B, and is formed, for example, as an optical fiber cable made of a resin material.

  The air motor 3 is formed by screwing the annular retaining member 4 to the female screw portion 2B of the housing 2 in a state where the large-diameter cylinder 3A1 of the motor case 3A is inserted into the motor housing portion 2A of the housing 2. It is integrally mounted in the housing 2.

  The rotating shaft 5 is formed as a hollow cylinder that is rotatably supported by the air motor 3 via an air bearing 3C. The rotating shaft 5 is disposed in the motor case 3A so as to extend in the axial direction about the axis OO. The rotating shaft 5 has a base end side (rear end side) integrally attached to the center of the turbine 3B, and a tip projecting forward from the motor case 3A. As shown in FIG. 2, the distal end side of the rotating shaft 5 is a tapered surface 5A having a diameter reduced toward the front side, and a thread portion for attaching the rotary atomizing head 18 to the distal end side of the tapered surface 5A. 5B is formed.

  The feed tube 6 supplies paint or cleaning fluid toward the rotary atomizing head 18 and extends to the tip of the rotary shaft 5 through the rotary shaft 5. The distal end side of the feed tube 6 protrudes from the distal end of the rotary shaft 5 and extends into the rotary atomizing head 18. On the other hand, the proximal end side of the feed tube 6 is inserted into the insertion hole 2C of the housing 2 in a positioned state.

  The feed tube 6 extends coaxially with the axis OO and has an inner cylinder 6A through which paint or cleaning fluid flows, and an outer cylinder 6A that is positioned on the outer peripheral side of the inner cylinder 6A. The cylinder 6B is formed. Thereby, the feed tube 6 is comprised as a double pipe as a whole. Inside the inner cylinder 6A is a paint supply passage 6C through which the paint or cleaning fluid flows, and between the inner cylinder 6A and the outer cylinder 6B is an annular cleaning fluid supply passage 6D through which the cleaning fluid flows. The paint supply passage 6C is connected to a paint supply source (not shown) such as a color change valve device, and the cleaning fluid supply passage 6D is connected to a cleaning fluid supply source (not shown).

  Furthermore, the inner cylinder 6A is formed longer in the axial direction than the outer cylinder 6B. Thereby, the front-end | tip part of the inner cylinder 6A becomes the protrusion part 6A1 which protruded ahead from the front-end | tip part 6B1 of the outer cylinder 6B. The opening of the protruding portion 6A1 is opposed to a paint receiving portion 22C of the hub member 22 described later in a slightly spaced state.

  A check valve 6E is provided at the distal end portion 6B1 of the outer cylinder 6B. The check valve 6E is formed in a cylindrical shape using a resin material having elasticity (spring property), a rubber material, or the like, for example, a fluorine-based resin material. In order to prevent the cleaning fluid from dripping, the check valve 6E is always in close contact with the outer peripheral surface of the inner cylinder 6A by an elastic force, and closes the opening side of the cleaning fluid supply passage 6D. On the other hand, when the cleaning fluid is supplied from the cleaning fluid supply passage 6D, the check valve 6E opens against the supply pressure of the cleaning fluid, so that the cleaning fluid is discharged from the cleaning fluid supply passage 6D. Is forgiving.

  The shaping air ring 7 is arranged on the outer peripheral side of the rotary atomizing head 18 and adjusts the spray pattern of the paint sprayed from the rotary atomizing head 18. The shaping air ring 7 includes a rear ring portion 8, a front ring portion 9, a first shaping air ejection hole 10, and a second shaping air ejection hole 11 which will be described later.

  The rear ring part 8 is formed as a stepped cylindrical body attached to the housing 2 so as to surround the front part of the air motor 3. On the outer periphery of the rear portion of the rear ring portion 8, a male screw portion 8A that is screwed to the female screw portion 2B of the housing 2 is provided.

  The front ring part 9 is formed as a stepped cylindrical body attached to the front part of the rear ring part 8 so as to surround the rotary atomizing head 18. The front end surface 9 </ b> A of the front ring portion 9 is disposed at a position that protrudes to the front side of the entire peripheral passage portion 25 </ b> B of the outer peripheral surface cleaning passage 25. The tip surface 9A is provided with a first shaping air ejection hole 10 and a second shaping air ejection hole 11.

  The front ring portion 9 has a ring inner peripheral surface 9B facing the outer peripheral surface 19E of the atomizing head main body 19 constituting the rotary atomizing head 18 with a gap. The ring inner peripheral surface 9B is formed as a concave conical surface that is expanded at the same angle as the outer peripheral surface 19E so as to face the outer peripheral surface 19E with a substantially constant gap dimension.

  A large number of first shaping air ejection holes 10 are provided in the circumferential direction and located near the outer periphery of the front end surface 9A of the front ring portion 9. Each first shaping air ejection hole 10 ejects shaping air toward the discharge edge 19J in order to adjust the spray pattern of the paint sprayed from the discharge edge 19J of the atomizing head main body 19. . Each first shaping air ejection hole 10 is connected to a first air source (not shown) via a first shaping air passage 16 described later.

  A plurality of second shaping air ejection holes 11 are provided on the inner peripheral side of the first shaping air ejection hole 10 and are provided on the front end surface 9A of the front ring portion 9. Each second shaping air ejection hole 11 ejects shaping air along the front portion of the outer peripheral surface 19 </ b> E of the atomizing head main body 19, similarly to each first shaping air ejection hole 10. Each second shaping air ejection hole 11 is connected to a second air source (not shown) via a second shaping air passage 17 described later.

  The annular gap 12 is defined between the ring inner peripheral surface 9B of the front ring portion 9 constituting the shaping air ring 7 and the outer peripheral surface 19E of the atomizing head main body 19. The annular gap 12 is formed as a conical (trumpet-shaped) thin space that expands toward the front side along the inner circumferential surface 9B and the outer circumferential surface 19E. Since the annular gap 12 is formed as a thin space, the assist air described later can be reliably applied to the cleaning fluid that has flowed out of the outer peripheral surface cleaning passage 25 into the annular gap 12. Accordingly, the cleaning fluid can be stably supplied to the front side portion of the outer peripheral surface 19E, and the cleaning efficiency of the outer peripheral surface 19E can be improved. Further, the backflow of the paint and the cleaning fluid can be prevented.

  The assist air ejection hole 13 is provided in the inner part (rear side) of the ring inner peripheral surface 9B of the front ring part 9 so as to open forward. The assist air ejection holes 13 are made up of a plurality of small holes formed in the circumferential direction, and are opened slightly inclined outward in the radial direction with respect to the axis OO of the rotating shaft 5. Each assist air ejection hole 13 is connected to, for example, a first shaping air passage 16. Each assist air ejection hole 13 ejects assist air (purge air) into the annular gap 12 to prevent the paint and cleaning fluid from flowing back into the annular gap 12 and from the outer peripheral surface cleaning passage 25 to the annular gap 12. The outflowing cleaning fluid can be smoothly guided toward the tip of the shaping air ring 7.

  As shown in FIG. 1, the inner cover 14 is provided so as to surround the housing 2, and its front end is fitted to the rear ring portion 8 of the shaping air ring 7 from the outside. Further, the outer cover 15 constitutes the outer peripheral surface of the rotary atomizing head type coating machine 1 and surrounds the shaping air ring 7 and the inner cover 14.

  The first shaping air passage 16 supplies compressed air from the first air source to each first shaping air ejection hole 10. The first shaping air passage 16 is provided, for example, between the housing 2 and the inner cover 14 and in the rear ring portion 8 and the front ring portion 9 of the shaping air ring 7.

  The second shaping air passage 17 supplies compressed air from the second air source to each second shaping air ejection hole 11. The second shaping air passage 17 is provided, for example, between the housing 2, the air motor 3 and the rear ring portion 8 of the shaping air ring 7, the rear ring portion 8, and the front ring portion 9.

  Next, the configuration of the rotary atomizing head 18 that is a characteristic part of the present embodiment will be described in detail.

  The rotary atomizing head 18 is attached to the tip of the rotary shaft 5 and sprays paint or the like supplied from the feed tube 6 by being rotated together with the rotary shaft 5 by the air motor 3. The rotary atomizing head 18 includes an atomizing head main body 19, a hub member 22, a cleaning fluid reservoir 23, an outer peripheral surface cleaning passage 25, a cleaning fluid / paint residual space 26, and a cleaning fluid / paint outflow passage 27 described later. ing.

  The atomizing head main body 19 constituting the rotary atomizing head 18 is formed as a cup-like body whose entire shape expands toward the front side. That is, in the atomizing head main body 19, the rear side which is the base end side is a cylindrical cylindrical portion 19A attached to the tip of the rotary shaft 5, and the cup portion 19B where the front side of the cylindrical portion 19A is widened forward. It has become.

  On the rear side of the atomizing head main body 19, a rotating shaft mounting hole 19C extending into the cup portion 19B with the cylindrical portion 19A as an opening is provided. The rotating shaft mounting hole 19C is for mounting the tip of the rotating shaft 5 and is reduced in diameter toward the front so as to correspond to the tapered surface 5A of the rotating shaft 5. Furthermore, a female screw portion 19D that is screwed into the male screw portion 5B of the rotary shaft 5 is formed in an intermediate portion in the axial direction of the rotary shaft attachment hole 19C.

  The outer peripheral side of the cup part 19B is an outer peripheral surface 19E that expands in a conical shape toward the front side. This outer peripheral surface 19E faces the ring inner peripheral surface 9B of the front ring portion 9 via the annular gap 12, and is formed as a smooth conical surface over the entire area in the front and rear directions and over the entire circumference. Has been.

  On the other hand, an annular cleaning fluid partition wall 19F is provided on the inner peripheral side of the cup portion 19B. The cleaning fluid partition wall 19F forms the bottom of the rotary shaft mounting hole 19C, and is provided to project radially inward at a position facing the tip portion 6B1 of the outer tube 6B of the feed tube 6 with a gap in the axial direction. Yes. The inner peripheral surface 19F1 of the cleaning fluid partition wall 19F has a gap 20 between the check valve 6E and the check valve 6E so as not to interfere when the check valve 6E of the feed tube 6 is opened.

  On the inner peripheral side of the cup part 19B, an annular paint partition wall 19G that protrudes inward in the radial direction at a position in front of the cleaning fluid partition wall 19F and surrounding the projecting part 6A1 of the inner tube 6A of the feed tube 6 is provided. Is provided. The inner peripheral surface 19G1 of the paint partition wall 19G has a gap 21 between the inner cylinder 6A so as not to interfere with the inner cylinder 6A. Further, the inner diameter side of the paint partition wall 19G protrudes forward while drawing an arc so that paint or the like does not flow out from the paint reservoir 24 described later to the cleaning fluid reservoir 23 side.

  The inner peripheral side of the cup part 19B is a cup inner peripheral surface 19H on the front side of the paint partition wall 19G. The cup inner peripheral surface 19H includes a back inner peripheral surface 19H1 that forms a peripheral wall of the paint reservoir 24 and the back inner peripheral surface. It is formed by the paint thin film surface 19H2 expanded from the front end of 19H1. The paint thinning surface 19H2 is formed as a dish-like curved surface that expands with a small axial dimension. The paint thinning surface 19H2 is used to distribute the paint flowing out from the paint reservoir 24 while thinning the paint toward the front side, and the tip (front end) of the paint thinning surface 19H2 discharges the thinned paint as paint particles. It has become.

  The hub member 22 is formed as a disk-like body provided on the cup inner peripheral surface 19H in front of the paint partition wall 19G of the atomizing head main body 19. The hub member 22 is disposed at a boundary position between the inner peripheral surface 19H1 of the back of the cup inner peripheral surface 19H and the paint thinning surface 19H2 so as to close the front side of the paint reservoir 24 described later. A large number of hub paint passages 22A (only two are shown) are provided on the outer peripheral side of the hub member 22 so as to flow between the inner peripheral surface 19H1 and the paint or cleaning fluid to the paint thinning surface 19H2. In the direction. Further, at a position near the center of the hub member 22, a plurality of hub cleaning fluid passages 22B (only two are shown) are provided on the front surface for allowing the cleaning fluid to flow out.

  Further, a paint receiving portion 22 </ b> C protruding in a conical shape toward the tip of the inner cylinder 6 </ b> A of the feed tube 6 is provided at the center of the rear surface of the hub member 22. The paint receiving portion 22C collides with the paint or cleaning fluid discharged in the axial direction from the paint supply passage 6C in the inner cylinder 6A. Therefore, as shown by an arrow A in FIG. 3, the paint and the cleaning fluid can be smoothly diffused by gradually changing the direction of the paint and the cleaning fluid in the radial direction by the paint receiving portion 22C.

  The cleaning fluid reservoir 23 is provided between the cleaning fluid partition wall 19F and the paint partition wall 19G of the atomizing head main body 19. The cleaning fluid reservoir 23 is formed as an annular space for storing the cleaning fluid flowing out from the cleaning fluid supply passage 6 </ b> D of the feed tube 6. On the outer diameter side of the cleaning fluid reservoir 23, an inflow side of an outflow hole portion 25A constituting an outer peripheral surface cleaning passage 25 described later is open in communication. Here, the diameter dimension of the cleaning fluid reservoir 23 is set so that the cleaning fluid / paint residual space 26 (rotary shaft) described later is used to incline the cleaning fluid / paint outflow passage 27 described later from the rear side toward the front side in the radial direction. It is set to a value larger than the diameter dimension of the mounting hole 19C).

  The paint reservoir 24 is provided between the paint partition wall 19 </ b> G of the atomizing head main body 19 and the hub member 22. The paint reservoir 24 is formed as an annular (doughnut-shaped) space for storing the paint flowing out from the paint supply passage 6 </ b> C of the feed tube 6. The paint reservoir 24 is a space for temporarily storing the paint or the cleaning fluid flowing out from the paint supply passage 6C and diffusing them.

  The outer peripheral surface cleaning passage 25 is provided on the outer peripheral side of the cup portion 19B so as to open to the outer peripheral surface 19E of the atomizing head main body 19. The outer peripheral surface cleaning passage 25 is the atomizing head main body as shown by an arrow B in FIG. 3 for cleaning fluid supplied from the outer cylinder 6B (cleaning fluid supply passage 6D) of the feed tube 6 to the cleaning fluid reservoir 23. 19 is discharged to the outer peripheral surface 19E. Here, the outer peripheral surface cleaning passage 25 communicates the cleaning fluid reservoir 23 and the outer peripheral surface 19E (annular gap 12) of the atomizing head main body 19, and is an outflow hole portion located upstream in the flow direction of the cleaning fluid. 25A and an all-around passage portion 25B located on the downstream side.

  A plurality of outflow holes 25A constituting the upstream portion of the outer peripheral surface cleaning passage 25 are provided in the atomizing head main body 19 at a predetermined interval in the circumferential direction (see FIG. 4). Each outflow hole portion 25A is a small-diameter passage extending radially from the inner diameter side to the outer diameter side, and the inner diameter side opens inward in the radial direction and communicates with the cleaning fluid reservoir 23. On the other hand, the outer diameter side of each outflow hole portion 25A is disposed to be inclined in the direction opposite to the rotation direction of the rotary atomizing head 18 (the direction indicated by the arrow R in FIG. 4).

  The entire peripheral passage portion 25B of the outer peripheral surface cleaning passage 25 is formed as an entire peripheral space communicating with the outer diameter side of each outflow hole portion 25A. This all-round passage portion 25B is formed as a thin conical cylindrical space (gap) whose outer diameter side gradually expands toward the front side, and its outermost diameter portion opens to the outer peripheral surface 19E of the atomizing head main body 19. ing. As a result, the entire circumferential passage portion 25B flows out to the outer peripheral surface 19E of the atomizing head main body 19 in a state in which the cleaning fluid supplied from each outflow hole portion 25A is temporarily accumulated by being continuously accumulated in the circumferential direction. Can do.

  The rotary atomizing head 18 configured as described above is supplied with paint from the paint supply passage 6 </ b> C of the feed tube 6 while being rotated at high speed by the air motor 3. At this time, the rotary atomizing head 18 discharges the paint supplied from the feed tube 6 through the paint reservoir 24, each hub paint passage 22A of the hub member 22, and the paint thinning surface 19H2 of the atomizing head main body 19. It is possible to spray from the edge 19J as countless paint particles atomized by centrifugal force. Further, when cleaning the paint adhering to the paint reservoir 24, each hub paint passage 22A of the hub member 22, the paint thinning surface 19H2 of the atomizing head main body 19 and the discharge edge 19J, the rotary atomizing head 18 is moved at a high speed. These can be cleaned by supplying a cleaning fluid from the paint supply passage 6C of the feed tube 6 while rotating.

  On the other hand, when cleaning the paint adhering to the outer peripheral surface 19E of the atomizing head main body 19, the cleaning fluid of the feed tube 6 is rotated as indicated by the arrow A in FIG. A cleaning fluid is supplied from the supply passage 6D. Thereby, as indicated by arrow B, the cleaning fluid is supplied to the outer peripheral surface 19E of the atomizing head main body 19 via the cleaning fluid reservoir 23 and the outer peripheral surface cleaning passage 25. The attached paint can be washed.

  The cleaning fluid / paint residual space 26 forms a part of the rotary atomizing head 18, and is between the rear surface of the cleaning fluid partition wall 19 </ b> F of the atomizing head main body 19 and the tip of the rotary shaft 5. The rotary shaft mounting hole 19C is formed. The cleaning fluid / paint residual space 26 is a space necessary for coaxially attaching the rotary atomizing head 18 to the tip of the rotary shaft 5. Here, a cleaning fluid / paint outflow passage 27 (described later) is provided in a corner between the rear surface of the cleaning fluid partition wall 19 </ b> F and the rotary shaft mounting hole 19 </ b> C in communication with the cleaning fluid / paint residual space 26.

  Next, the configuration of the cleaning fluid / paint outflow passage 27 which is a characteristic part of the present embodiment will be described in detail.

  A plurality of, for example, four (see FIG. 4) cleaning fluid / paint outflow passages 27 are provided at intervals in the circumferential direction on the outer peripheral side of the cleaning fluid partition wall 19F constituting the atomizing head main body 19 of the rotary atomizing head 18. ing. As shown by arrow C in FIG. 3, each cleaning fluid / paint outflow passage 27 passes through, for example, the clearance 20 between the feed tube 6 and the cleaning fluid partition wall 19F and the clearance 21 between the feed tube 6 and the coating partition wall 19G. Or, when the paint flows into the cleaning fluid / paint residual space 26, the cleaning fluid or paint flows out to the outer peripheral surface 19E side of the atomizing head main body 19 through the outer peripheral surface cleaning passage 25 as indicated by arrow D. It is.

  Each of the cleaning fluid / paint outflow passages 27 is open to the cleaning fluid / paint residual space 26 with the rear side, which is the upstream side in the flow direction, serving as an inlet 27A. On the other hand, the front side, which is the downstream side of each cleaning fluid / paint outflow passage 27, serves as an outlet 27 </ b> B and opens to the outer diameter portion of the cleaning fluid reservoir 23.

  Specifically, the inflow port 27A has a rotation shaft mounting hole 19C that opens at a corner of the cleaning fluid / paint residual space 26 between the rotation shaft mounting hole 19C of the atomizing head main body 19 and the cleaning fluid partition wall 19F. The cleaning fluid partition wall 19F is formed. Accordingly, by rotating the rotary atomizing head 18 at a high speed, the cleaning fluid and the paint that have entered the cleaning fluid / paint residual space 26 flow radially outward due to the centrifugal force. Cleaning fluid and paint can be efficiently introduced.

  Here, each of the cleaning fluid / paint outflow passages 27 is formed as a small circular hole, and the inner diameter dimension d thereof is set to a value as shown in Equation 1 below.

  Further, each of the cleaning fluid / paint outflow passages 27 is disposed so as to incline radially outward from the rear side to the front side. That is, each cleaning fluid / paint outflow passage 27 is inclined outward in the radial direction with an angle α with respect to the axis OO of the rotating shaft 5.

  In this case, the angle α is a dimensional relationship of each part of the rotary atomizing head 18, for example, a dimension such as an angle at which a drill can be inserted into the rotary shaft mounting hole 19C when drilling each cleaning fluid / paint outflow passage 27. It is set according to conditions. That is, the angle α of each of the cleaning fluid / paint outflow passages 27 is set as shown in Equation 2 below.

  The turbine air supply conduit 28 supplies turbine air (compressed air) toward the impeller of the turbine 3 </ b> B, and is provided in the housing 2 and the motor case 3 </ b> A of the air motor 3. On the other hand, the turbine air discharge conduit 29 discharges the exhaust air after driving the turbine 3B to the outside (atmosphere) of the housing 2, and is provided in the motor case 3A of the housing 2 and the air motor 3.

  The rotary atomizing head type coating machine 1 according to the first embodiment has the above-described configuration. Next, an operation when performing a painting operation using the rotary atomizing head type coating machine 1 will be described. .

  Bearing air is supplied to the air bearing 3C of the air motor 3, and turbine air is supplied to the turbine 3B to rotationally drive the rotary shaft 5. As a result, the rotary atomizing head 18 rotates at a high speed together with the rotary shaft 5. In this state, the paint selected by the color change valve device (not shown) is supplied from the paint supply passage 6C in the inner cylinder 6A of the feed tube 6 to the rotary atomizing head 18, whereby the paint is rotated and atomized. It can be sprayed from the head 18 as paint particles. In this case, the coating particles sprayed from the rotary atomizing head 18 can be charged to a high voltage by applying a high voltage to the rotary atomizing head 18 or the like.

  Thereby, since the high voltage is applied to the paint particles sprayed from the rotary atomizing head 18 by the high voltage generator, the paint particles charged to the high voltage are applied to the article connected to the ground. It can fly toward and apply efficiently.

  On the other hand, when the paint is sprayed from the rotary atomizing head 18, the shaping air is ejected from the shaping air ejection holes 10 and 11 of the shaping air ring 7 in order to atomize the spray paint and shape the spray pattern. Thereby, shaping air can be made to collide with the liquid yarn of the paint flying from the rotary atomizing head 18, and the paint can be atomized.

  Next, when the painting work is finished and the rotary atomizing head 18 is cleaned in preparation for the next painting work, that is, the paint adhering to the atomizing head main body 19 and the hub member 22 of the rotary atomizing head 18 is washed. The case where it does is demonstrated.

  In this case, as indicated by an arrow A in FIG. 3, the cleaning fluid (thinner, compressed air, etc.) selected by the color change valve device is applied to the feed tube 6 while rotating the rotary atomizing head 18 at a high speed. It is supplied to the rotary atomizing head 18 from the supply passage 6C. The cleaning fluid flows along the hub member 22 and the cup inner peripheral surface 19H of the atomizing head main body 19 to the hub member 22, the inner peripheral surface 19H1 of the cup inner peripheral surface 19H, the paint thinning surface 19H2, and the like. The attached paint can be washed.

  Next, the case where the coating material adhering to the outer peripheral surface 19E of the atomizing head main body 19 of the rotary atomizing head 18 is washed will be described.

  In this case, the cleaning fluid flows out from the cleaning fluid supply passage 6 </ b> D of the feed tube 6 to the cleaning fluid reservoir 23 while rotating the rotary atomizing head 18 at a high speed. The cleaning fluid stored in the cleaning fluid reservoir 23 flows out to the annular gap 12 through the outer peripheral surface cleaning passage 25 by centrifugal force as indicated by an arrow B in FIG. On the other hand, the assist air ejection hole 13 supplies assist air to the annular gap 12. As a result, the assist air ejected from the assist air ejection hole 13 causes the cleaning fluid that has flowed out from the entire peripheral passage portion 25B of the outer peripheral surface cleaning passage 25 into the annular gap 12 along the outer peripheral surface 19E of the atomizing head main body 19. The paint adhering to the outer peripheral surface 19E can be washed.

  Here, when coating is performed by discharging the paint from the feed tube 6, the paint or the bright material contained in the paint collides with the paint receiving part 22 </ b> C of the hub member 22, so that the paint receiving part 22 </ b> C is worn. There are things to do. In this case, if the cleaning fluid or paint is discharged toward the paint receiving portion 22C, the cleaning fluid or paint is likely to be scattered.

  FIG. 11 shown as a reference example shows a rotary atomizing head 101 in which the cleaning fluid / paint outflow passage 27 is not provided. The rotary atomizing head 101 according to the reference example differs from the rotary atomizing head 18 according to the first embodiment in that the cleaning fluid / paint outflow passage 27 is not provided. Therefore, in the reference example of FIG. 11, except for the cleaning fluid / paint outflow passage 27, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the reference example shown in FIG. 11, as indicated by an arrow X, when the cleaning fluid is discharged from the inner cylinder 6 </ b> A (paint supply passage 6 </ b> C) of the feed tube 6, a large amount of cleaning fluid flows from the paint reservoir 24 to the cup inner peripheral surface 19 </ b> H. Flowing into. However, a part of the cleaning fluid passes through the clearance 21 between the feed tube 6 and the paint partition wall 19G and the clearance 20 between the feed tube 6 and the cleaning fluid partition wall 19F as indicated by an arrow Y, and the cleaning fluid / paint residual space 26 Flow into. As indicated by an arrow Z, the cleaning fluid or the like flowing into the cleaning fluid / paint residual space 26 further enters the air motor 3 through the gap between the feed tube 6 and the rotary shaft 5.

  When cleaning fluid or the like having a solvent component enters the air motor 3, for example, when the cleaning fluid or the like comes into contact with the rotational speed detection cable 3D, the rotational speed detection cable 3D is melted to detect the rotational speed of the turbine 3B. It may be possible to cause trouble. Even in an atmosphere containing a vaporized solvent component, the detection site on the tip surface of the rotation speed detection cable 3D may be clouded. Further, when the infiltrated cleaning fluid reaches the turbine air discharge conduit 29, the cleaning fluid may come into contact with a control valve or the like for controlling the painting robot via the turbine air discharge conduit 29, which may cause malfunction. is there. Further, when the paint flowing into the cleaning fluid / paint residual space 26 enters between the rotary shaft 5 and the air bearing 3C of the air motor 3, the pigment contained in the paint adheres to the air bearing 3C, and the rotation of the air motor 3 is performed. It may cause defects.

  However, according to the first embodiment, the cleaning fluid / paint residual space is provided in the cleaning fluid partition wall 19F of the atomizing head body 19 of the rotary atomizing head 18 through the gap 20 between the feed tube 6 and the cleaning fluid partition wall 19F. A cleaning fluid / paint outflow passage 27 through which the cleaning fluid or paint flowing into the outer surface 26 flows out toward the outer peripheral surface cleaning passage 25 is provided.

  Therefore, when the painting operation is completed, the rotary atomizing head 18 is rotated at a high speed together with the rotary shaft 5 by the air motor 3. As a result, the cleaning fluid or paint flowing into the cleaning fluid / paint residual space 26 is washed by the cleaning fluid / paint outflow passage 27 as shown by arrow D in FIG. As shown by arrow B, the outer peripheral surface cleaning passage 25 can flow out toward the outer peripheral surface 19E of the rotary atomizing head 18 (the atomizing head main body 19).

  As a result, even if a part of the cleaning fluid or the paint flows into the cleaning fluid / paint residual space 26, the cleaning fluid / paint outflow passage 27 causes the cleaning fluid / paint outflow passage 27 by the centrifugal force when the rotary atomizing head 18 is driven to rotate. The cleaning fluid or the paint can be discharged from the paint residual space 26 to the outside. As a result, since no cleaning fluid or paint remains in the cleaning fluid / paint residual space 26, it is possible to prevent the cleaning fluid or paint from being scattered around or mixed into the next color paint. Can be prevented, and the reliability of the paint finish can be improved.

  In addition, by preventing the occurrence of coating failure due to the cleaning fluid or paint entering the cleaning fluid / paint residual space 26, the frequency of disassembling and cleaning the rotary atomizing head 18 can be reduced, and the productivity of the painting work can be reduced. Can be improved.

  Furthermore, by not allowing the cleaning fluid or paint to remain in the cleaning fluid / paint residual space 26, it is possible to suppress the cleaning fluid or paint from flowing into the air motor 3. Accordingly, for example, damage to the rotational speed detection cable 3D due to cleaning fluid or solvent contained in the paint can be prevented, and rotation failure of the air motor 3 due to adhesion of pigments contained in the paint can be prevented, thereby improving the durability of the air motor 3. Can be improved. Moreover, it is possible to prevent malfunction of the painting robot due to contact with the solvent component, and to improve reliability.

  A plurality of cleaning fluid / paint outflow passages 27 are provided at intervals in the circumferential direction, and are inclined by an angle α from the rear side to the front side in the radial direction. Thus, when the rotary atomizing head 18 is driven to rotate at a high speed, the cleaning fluid and the paint in the cleaning fluid / paint residual space 26 are positively discharged through the cleaning fluid / paint outflow passage 27 using the centrifugal force at this time. can do.

  The outlet 27 B of the cleaning fluid / paint outflow passage 27 is configured to open to the cleaning fluid reservoir 23. Accordingly, the cleaning fluid and the paint can be discharged from the cleaning fluid / paint residual space 26 to the outer peripheral surface 19E side of the rotary atomizing head 18 through the cleaning fluid reservoir 23 and the outer peripheral surface cleaning passage 25.

  Further, the rotary atomizing head 18 is located behind the coating film thinning surface 19H2 of the cup inner circumferential surface 19H of the atomizing head main body 19 and in front of the coating partition wall 19G, and the coating material flows out to the outer circumferential side. A hub member 22 having a hub paint passage 22A is provided. The hub member 22 is provided with a paint receiving portion 22C that is located at the center of the rear surface and projects in a conical shape toward the tip of the inner cylinder 6A of the feed tube 6. Accordingly, a part of the cleaning fluid or a part of the paint that collides with the paint receiving portion 22C of the hub member 22 and a part of the paint are formed between the gap 21 between the feed tube 6 and the paint partition wall 19G and between the feed tube 6 and the cleaning fluid partition wall 19F. It flows into the cleaning fluid / paint residual space 26 through the gap 20. However, the cleaning fluid or paint flowing into the cleaning fluid / paint residual space 26 can flow out toward the outer peripheral surface cleaning passage 25 through the cleaning fluid / paint outflow passage 27.

  Next, FIG. 5 and FIG. 6 show a second embodiment of the present invention. The feature of the present embodiment is that a liquid collecting part for expanding the inlet is provided at the inlet of the cleaning fluid / paint outlet passage. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified.

  5 and 6, the cleaning fluid / paint outflow passage 31 according to the second embodiment is substantially the same as the cleaning fluid / paint outflow passage 27 according to the first embodiment. Four cleaning fluid partitions 19F are provided at intervals in the circumferential direction so as to communicate with the cleaning fluid reservoir 23. However, the cleaning fluid / paint outflow passage 31 according to the second embodiment has the inflow port 31A opened to a liquid collection unit 32 described later, and therefore the cleaning fluid / paint outflow passage according to the first embodiment. 27. The outlet 31B is open to the cleaning fluid reservoir 23. Further, the inner diameter dimension and the angle of the cleaning fluid / paint outflow passage 31 are set within the range of values described in the first embodiment.

  The liquid collection unit 32 according to the second embodiment is provided at the inlet 31 </ b> A of the cleaning fluid / paint outflow passage 31. Specifically, the liquid collection unit 32 is disposed on the outer peripheral side of the cleaning fluid partition wall 19 </ b> F constituting the atomizing head main body 19 of the rotary atomizing head 18 and opens rearward toward the cleaning fluid / paint residual space 26. It is formed as a substantially semicircular annular groove (overall groove). The liquid collection part 32 is set to have a semicircular diameter dimension, that is, a width dimension larger than an inner diameter dimension of the cleaning fluid / paint outflow passage 31.

  As a result, the liquid collection part 32 expands the inlet 31A side of the cleaning fluid / paint outflow passage 31 to move the cleaning fluid / paint remaining space 26 to the outer peripheral side along the cleaning fluid partition wall 19F. Alternatively, the paint can be collected and efficiently supplied to the cleaning fluid / paint outflow passage 31. In this case, the liquid collection part 32 formed as a substantially semicircular annular groove can collect a wide range of cleaning fluid from low viscosity to high viscosity paint.

  Thus, also in the second embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. In particular, according to the second embodiment, the inlet 31A of the cleaning fluid / paint outlet passage 31 is provided with the liquid collecting portion 32 for expanding the inlet 31A. As a result, the cleaning fluid or paint that moves to the outer periphery side by centrifugal force in the cleaning fluid / paint residual space 26 can be collected once by the liquid collecting section 32 and guided to the inlet 31A of the cleaning fluid / paint outflow passage 31. The cleaning fluid and the paint can be efficiently discharged through the cleaning fluid / paint outflow passage 31.

  Next, FIG. 7 shows a third embodiment of the present invention. A feature of the present embodiment is that a liquid collecting part for enlarging the inlet is provided at the inlet of the cleaning fluid / paint outflow passage, and the groove has a larger groove depth dimension toward the outer peripheral side. This is because it is configured as a substantially triangular groove. In the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified.

  In FIG. 7, the cleaning fluid / paint outflow passage 41 according to the third embodiment is substantially the same as the cleaning fluid / paint outflow passage 27 according to the first embodiment, and the cleaning fluid / paint residual space 26 and the cleaning fluid reservoir. Four cleaning fluid partition walls 19F are provided on the outer peripheral side of the cleaning fluid partition wall 19F at intervals in the circumferential direction. However, the cleaning fluid / paint outflow passage 41 according to the third embodiment has the inflow port 41A opened to a liquid collection section 42 described later, and therefore the cleaning fluid / paint outflow passage according to the first embodiment. 27. The outlet 41B is open to the cleaning fluid reservoir 23. Further, the inner diameter size and angle of the cleaning fluid / paint outflow passage 41 are set within the range of the values described in the first embodiment.

  The liquid collection part 42 according to the third embodiment is provided at the inlet 41 </ b> A of the cleaning fluid / paint outflow passage 41. Specifically, the liquid collecting part 42 is disposed on the outer peripheral side of the cleaning fluid partition wall 19F constituting the atomizing head main body 19 of the rotary atomizing head 18, and opens rearward toward the cleaning fluid / paint residual space 26. It is formed as an annular groove (overall groove). The liquid collection part 42 according to the third embodiment is formed as a substantially triangular concave groove in which the axial groove depth dimension gradually increases toward the outer peripheral side, and the cleaning fluid is formed in the deepest part (outermost peripheral part). / The inlet 41A of the paint outflow passage 41 is open in communication.

  As a result, the liquid collection part 42 expands the inlet 41A side of the cleaning fluid / paint outflow passage 41 to move the cleaning fluid / paint residual space 26 to the outer peripheral side along the cleaning fluid partition wall 19F. Alternatively, the paint can be collected and efficiently supplied to the cleaning fluid / paint outflow passage 41. In this case, the substantially triangular liquid collection part 42 whose groove depth dimension increases toward the outer peripheral side is suitable for, for example, guiding cleaning fluid or low-viscosity paint to the cleaning fluid / paint outflow passage 41.

  Thus, also in the third embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the second embodiment described above. In particular, according to the third embodiment, the inflow port 41A of the cleaning fluid / paint outflow passage 41 is provided with the liquid collecting portion 42 for enlarging the inflow port 41A. As a result, the cleaning fluid or paint that moves to the outer periphery side by centrifugal force in the cleaning fluid / paint residual space 26 can be collected once by the liquid collecting section 42 and guided to the inlet 41A of the cleaning fluid / paint outflow passage 41. The cleaning fluid and the paint can be efficiently discharged through the cleaning fluid / paint outflow passage 41. Further, the substantially triangular liquid collecting part 42 whose groove depth dimension increases toward the outer peripheral side can efficiently guide the cleaning fluid and the low-viscosity paint to the cleaning fluid / paint outflow passage 41.

  Next, FIG. 8 shows a fourth embodiment of the present invention. The feature of this embodiment is that the outlet of the cleaning fluid / paint outflow passage opens into the outer peripheral surface cleaning passage. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is simplified.

  In FIG. 8, a plurality of, for example, four cleaning fluid / paint outflow passages 51 according to the fourth embodiment are provided at intervals in the circumferential direction, similar to the cleaning fluid / paint outflow passage 27 according to the first embodiment. (Only two are shown). However, in the cleaning fluid / paint outflow passage 51 according to the fourth embodiment, the inflow port 51A opens to the cleaning fluid / paint residual space 26, and the outflow port 51B opens to the outflow hole 25A of the outer peripheral surface cleaning passage 25. This is different from the cleaning fluid / paint outflow passage 27 according to the first embodiment. Note that the inner diameter size and angle of the cleaning fluid / paint outflow passage 51 are set to the value ranges described in the first embodiment.

  As a result, each cleaning fluid / paint outflow passage 51 can cause the cleaning fluid or paint that has entered the cleaning fluid / paint residual space 26 to flow out into the outflow hole 25 </ b> A of the outer peripheral surface cleaning passage 25.

  Thus, also in the fourth embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. In particular, according to the fourth embodiment, the outlet 51B of the cleaning fluid / paint outflow passage 51 is configured to open to the outer peripheral surface cleaning passage 25. Accordingly, the cleaning fluid or paint that has entered the cleaning fluid / paint residual space 26 can be discharged to the outer peripheral surface cleaning passage 25 by the cleaning fluid / paint outlet passage 51 and easily discharged to the outside from the outer peripheral surface cleaning passage 25. be able to.

  Next, FIG. 9 shows a fifth embodiment of the present invention. The feature of this embodiment is that the thin coating surface of the rotary atomizing head is formed as a deep curved surface that is widened with a large axial dimension. In the fifth embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified.

  In FIG. 9, the rotary atomizing head 18 'according to the fifth embodiment has an atomizing head main body 19' in substantially the same manner as the rotary atomizing head 18 according to the first embodiment. However, the rotary atomizing head 18 'according to the fifth embodiment is formed as a deep curved surface in which the cup inner peripheral surface 19H' of the atomizing head main body 19 'is expanded with a large axial dimension. Thus, it is different from the rotary atomizing head 18 according to the first embodiment.

  Thus, also in the fifth embodiment configured as described above, it is possible to obtain substantially the same function and effect as those of the first embodiment described above. In particular, according to the fifth embodiment, the cleaning fluid / paint outflow is not limited to the rotary atomizing head 18 according to the first embodiment, but also to the rotary atomizing head 18 ′ according to the fifth embodiment. A passage 27 'can be provided.

  In the second embodiment, the liquid collection portion 32 formed of an annular groove (entire circumferential groove) is provided so as to communicate with all of the four cleaning fluid / paint outflow passages 31. However, the present invention is not limited to this. For example, the present invention may be configured as a modification shown in FIG. That is, in the modified example shown in FIG. 10, it is possible to provide a separate liquid collecting part 62 for each of the four cleaning fluid / paint outflow passages 61. This configuration can be similarly applied to the third embodiment.

  In the first embodiment, when four cleaning fluid / paint outflow passages 27 are provided on the outer peripheral side of the cleaning fluid partition wall 19 </ b> F constituting the atomizing head main body 19 of the rotary atomizing head 18 at intervals in the circumferential direction. Is illustrated. However, the present invention is not limited to this, and two, three, or five or more cleaning fluid / paint outflow passages 27 may be provided at intervals in the circumferential direction. This configuration can be similarly applied to other embodiments.

  In the first embodiment, as the rotary atomizing head type coating machine 1, a direct charging type electrostatic coating machine that directly applies a high voltage to the paint supplied to the rotary atomizing head 18 is taken as an example. explained. However, the present invention is not limited to this. For example, the outer peripheral position of the rotary atomizing head 18 has an external electrode that discharges a high voltage, and the paint particles sprayed from the rotary atomizing head 18 by the discharge from the external electrode are used. It is good also as a structure applied to the indirect charging type electrostatic coating machine which applies a high voltage. Furthermore, the present invention can also be applied to a non-electrostatic coating machine that performs coating without applying a high voltage to the paint. This configuration can be similarly applied to other embodiments.

DESCRIPTION OF SYMBOLS 1 Rotating atomizing head type coating machine 3 Air motor 5 Rotating shaft 6 Feed tube 6A Inner cylinder 6A1 Protruding part 6B Outer cylinder 6B1 Tip part 6E Check valve 18, 18'101 Rotating atomizing head 19, 19 'Atomizing head main body 19C Rotation Shaft mounting hole 19E Outer peripheral surface 19F Cleaning fluid partition wall 19G Paint partition wall 19H, 19H 'Cup inner peripheral surface 19H2 Paint thinning surface 20, 21 Gap 22 Hub member 22A Hub paint passage 22C Paint receiving portion 23 Cleaning fluid reservoir 25 Outer peripheral surface cleaning passage 26 Cleaning fluid / paint residual space 27, 31, 41, 51, 61, 27 ′ Cleaning fluid / paint outflow passage 27A, 31A, 41A, 51A Inlet 27B, 31B, 41B, 51B Outlet 32, 42, 62 Liquid collection Part α Cleaning fluid / Paint outflow passage angle

Claims (6)

An air motor powered by compressed air;
A hollow rotating shaft that is rotatably supported by the air motor and has a tip protruding forward from the air motor;
In order to supply paint or cleaning fluid, it extends through the rotating shaft to the tip of the rotating shaft and is positioned at the center of the shaft and positioned on the outer peripheral side of the inner tube for supplying the coating material or cleaning fluid. A feed tube comprising an outer cylinder that opens at a position retracted from the tip of the inner cylinder and supplies a cleaning fluid to and from the inner cylinder;
Formed as a cup-shaped body that expands toward the front side, and has a rotating shaft mounting hole to which the tip of the rotating shaft is mounted on the rear side, and a paint thinning surface that sprays the coating material supplied from the feed tube on the front side A rotary atomizing head having
The rotary atomizing head is
A cleaning fluid partition wall protruding radially inward at a position facing the tip portion of the outer tube of the feed tube;
A coating partition wall protruding inward in the radial direction at a position surrounding the protruding portion of the inner cylinder on the front side of the cleaning fluid partition wall;
A cleaning fluid reservoir that is located between the cleaning fluid partition and the paint partition and stores cleaning fluid supplied from an outer cylinder of the feed tube;
An outer peripheral surface cleaning passage opened in the outer peripheral surface of the rotary atomizing head in order to allow the cleaning fluid supplied from the outer cylinder of the feed tube to the outer peripheral surface of the rotary atomizing head to flow out to the outer peripheral surface of the rotary atomizing head;
A rotary atomizing head type coating machine comprising a cleaning fluid / paint residual space formed in the rotary shaft mounting hole of the rotary atomizing head between the rear surface of the cleaning fluid partition and the tip of the rotary shaft. In
The cleaning fluid or paint that has flowed into the cleaning fluid / paint residual space through the gap between the feed tube and the cleaning fluid partition flows out to the cleaning fluid partition of the rotary atomizing head toward the outer peripheral surface cleaning passage. A rotary atomizing head type coating machine characterized in that a cleaning fluid / paint outflow passage is provided.   2. The rotary atomizing head type coating machine according to claim 1, wherein a plurality of the cleaning fluid / paint outflow passages are provided at intervals in the circumferential direction and are inclined from the rear side toward the front side in the radial direction.   The rotary atomizing head type coating machine according to claim 1 or 2, wherein a liquid collecting part for enlarging the inlet is provided at an inlet of the cleaning fluid / paint outlet passage.   The rotary atomizing head type coating machine according to claim 1, 2 or 3, wherein an outlet of the cleaning fluid / paint outflow passage opens to the cleaning fluid reservoir.   The rotary atomizing head type coating machine according to claim 1, 2 or 3, wherein an outlet of the cleaning fluid / paint outflow passage opens into the outer peripheral surface cleaning passage. The rotary atomizing head is provided with a hub member having a hub paint passage on the outer peripheral side, located at the back of the paint thinning surface and on the front side of the paint partition,
The hub member is provided with a paint receiving portion that is located at the center of the rear surface and protrudes conically toward the tip of the inner tube of the feed tube,
A part of the cleaning fluid or a part of the paint splashed by colliding with the paint receiving portion of the hub member passes through the gap between the feed tube and the paint partition wall and the gap between the feed tube and the cleaning fluid partition wall. The rotary atomizing head type coating machine according to claim 1, 2, 3, 4 or 5, which flows into the cleaning fluid / paint residual space.

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