JP2014144388A - Coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus which efficiently switches coating between aqueous coating and solvent coating.SOLUTION: A coating apparatus 100 comprises: a bell main body 10 having a rotary atomization head 20; a water base paint passage 15 which is connected with the rotary atomization head 20; and a solvent paint passage 16 which is connected with the rotary atomization head 20 without connecting with the water base paint passage 15. It is preferable that the coating apparatus 100 further comprises: a voltage application device which establishes electrical continuity with the rotary atomization head 20; a cartridge 21 which may connect with the water base paint passage 15; and a collar change valve 30 which is positioned at the exterior of the bell main body 10 and is connected with the solvent paint passage 16.

Description

  The present invention relates to a coating apparatus.

  2. Description of the Related Art An electrostatic coating apparatus is known as a coating apparatus having excellent coating efficiency on a painted surface and smoothness of a coated film after coating. An example of a coating head provided in the electrostatic coating apparatus is a coating gun. As an application of the electrostatic coating apparatus, there is high-quality coating such as painting of an automobile body. For such high-quality coating, it is necessary to selectively use a water-based paint (conductive paint) and a solvent paint (non-conductive paint).

  Patent Literature 1 describes a coating apparatus for applying a water-based paint and a solvent paint using a common application gun. Such a coating apparatus includes a pipe for each of a non-conductive paint and a conductive paint in the gun. Both pipes can be selectively connected to the application head through a switching valve. A common line for the non-conductive paint and the conductive paint exists between the switching valve and the application head.

JP 05-049976 A

  The length of the pipe part shared as a whole is shortened as compared with the prior art in the coating apparatus described in Patent Document 1. For this reason, it is easy to clean the pipeline at the time of paint switching. However, the common pipeline of the water-based paint and the solvent paint requires a replacement operation with a cleaning agent when the paint is switched.

  Specifically, when the paint is switched from a solvent paint to a water-based paint, the solvent paint in the pipeline that is used by the solvent detergent must be washed, and then the detergent in the pipeline must be replaced with the water detergent. There is. The same applies to the reverse case.

  Without such a process, paint agglomerates can form in the common line and block it. An object of the present invention is to solve such problems and to provide a coating apparatus capable of efficiently switching between aqueous coating and solvent coating.

  The coating apparatus of the present invention includes a bell body having a rotary atomizing head, an aqueous paint path connected to the rotary atomizing head, and a solvent paint connected to the rotary atomizing head without being connected to the aqueous paint path. A route.

  The coating apparatus of the present invention is located outside the bell body and connected to the solvent paint path, with a voltage applying device electrically conducting with the rotary atomizing head, a cartridge connectable to the water-based paint path. It is preferable to further include a color change valve.

  It is preferable that the coating apparatus of the present invention further includes an outer pipe connected to the solvent paint path and the color change valve, and a cleaning agent tank connected to the color change valve. It is preferable that the solvent paint path is located in the bell main body and communicates with the cleaning agent tank via the outer pipe and the color change valve.

  The cartridge is preferably detachable from the bell body. It is preferable that the water-based paint path has an inflow end which is located in the bell main body and can be connected to the paint container of the cartridge via a connection surface of the bell main body and the cartridge. It is preferable that the bell main body further has a cleaning path branched from the water-based paint path, and the cleaning path is connected to a lumen of the water-based paint path.

  It is preferable that the bell main body further has a hollow rotary shaft connected to the rotary atomizing head. The bell main body does not have an end surface that penetrates the hollow rotary shaft and is connected to the rotary atomizing head of the hollow rotary shaft, and a cleaning nozzle that is connected to a space surrounded by the inner wall of the rotary atomizing head. preferable. It is preferable that the bell body does not have a cleaning nozzle that penetrates the hollow rotating shaft.

  It is preferable that each of the water-based paint path and the solvent paint path passes through the hollow rotary shaft and has a delivery end. The delivery ends of the water-based paint path and the solvent paint path are preferably in contact with an end face connected to the rotary atomizing head of the hollow rotary shaft and a space surrounded by the inner wall of the rotary atomizing head.

  According to the present invention, it is possible to provide a coating apparatus capable of efficiently switching between aqueous coating and solvent coating.

It is a schematic diagram showing a painting device concerning an embodiment. It is a figure which shows the coating device concerning embodiment. It is a figure of the bell main body and voltage application apparatus concerning an embodiment. It is a figure of a bell main part and a washing unit concerning an embodiment. It is a figure of the front-end | tip part of the bell main body concerning embodiment. It is a figure of the coating device concerning a 1st comparative form. It is a figure of the atomization part concerning the 2nd comparative form. It is sectional drawing of the atomization part concerning a 2nd comparison form. It is sectional drawing of the atomization part concerning a 3rd comparison form.

[Overview]
As shown in FIG. 1, the coating apparatus 100 includes a rotary atomizing head 20 (bell cup) and a plurality of feed tubes (paint path). The plurality of feed tubes includes an aqueous paint path 15 and a solvent paint path 16. The water-based paint path 15 is a first paint path connected to the rotary atomizing head 20. The solvent paint path 16 is a second paint path connected to the rotary atomizing head 20 without being connected to the water-based paint path 15.

  The aqueous paint path 15 may communicate with the cartridge 21. In this case, the aqueous paint path 15 sends the aqueous paint 1 received from the cartridge 21 via the inflow end 52 to the rotary atomizing head 20 via the delivery end 53. As the water-based paint, an emulsion (dispersion type) paint is preferable.

  As shown in FIG. 2 to be described later, the solvent coating path 16 sends the solvent coating 4 received from an arbitrary container or pipe line via the inflow end 54 to the rotary atomizing head 20 via the delivery end 55. The delivery end 53 and the delivery end 55 function as a discharge port for each paint.

  The water-based paint path 15 and the solvent paint path 16 communicate separately to the rotary atomizing head. For this reason, the common part where the water-based paint 1 and the solvent paint 4 are mixed is only the rotary atomizing head. Since the rotary atomizing head rotates at a high speed, the cleaning agent at the time of cleaning is scattered and does not stay in the common part.

  For this reason, even when switching from the water-based paint 1 to the solvent paint 4, it is not necessary to replace the cleaning agent. That is, the coating apparatus 100 can be efficiently switched from aqueous coating to solvent coating. Since the coating apparatus 100 does not require replacement of the cleaning agent even when switching from the solvent paint to the water-based paint, bidirectional switching between the water-based paint and the solvent paint is efficient.

  The coating apparatus 100 can easily combine an aqueous coating process with a solvent coating process. For this reason, the coating method using the coating apparatus 100 uses a thinner amount of cleaning thinner such as xylene, ethylbenzene, and petroleum aromatic hydrocarbon, which will be described later.

[Details]
As shown in FIG. 2, the coating apparatus 100 further includes a bell body 10 having a rotary atomizing head 20, a cartridge 21 connected to the aqueous paint path 15, and a color change valve 30 connected to the solvent paint path 16.

  The color change valve 30 is preferably located outside the bell body 10. In this case, the color change valve 30 can be used alternately by the plurality of bell bodies 10. The rotary atomizing head 20, the water-based paint path 15, and the solvent paint path 16 are located in the bell body 10.

  The color change valve 30 includes color valves 31 to 36. The color change valve has an internal paint path 67 having a number of branches equal to the number of color valves. The number of color valves included in the color change valve is preferably four or more. This is because at least two color valves are required for the cleaning agent supply path and the cleaning air supply path.

  The color valves 31 to 36 open and close the pipelines independently. The color valve 31 is connected to the internal paint path 67 through the connecting portion 61. The color valves 32 to 36 are connected to the internal paint path 67 through the connection portions 62 to 66, respectively.

  The color valve 31 sends the solvent paint 4 received from a paint tank (not shown) to the internal paint path 67 through the connecting portion 61. The internal paint path 67 sends the solvent paint 4 received from the color valve 31 to the external pipe 17.

  Each of the color valves 32 to 34 receives a solvent paint having a color different from that of the solvent paint 4 from a paint tank (not shown). Each of the color valves 32 to 34 sends solvent paint received from a paint tank (not shown) to the internal paint path 67. The color change valve opens and closes the color valves 31 to 36 according to a command received from the outside or a predetermined procedure.

  The coating apparatus 100 further includes an outer pipe 17, a color valve, and a cleaning agent tank (not shown). For example, the color valve 36 in the color change valve 30 may be used as the valve. The color valve 36 communicates with the external pipe 17 via the internal paint path 67.

  It is preferable that the cleaning agent tank communicates with the color valve 35 or 36 farthest from the bell body 10 so that the cleaning agent can clean the solvent paint supplied from the color valves 31 to 34. In the present embodiment, a cleaning agent tank (not shown) communicates with the color valve 36.

  The color valve 36 sends the cleaning agent received from a cleaning agent tank (not shown) to the internal paint path 67 via the connection portion 66. An air tank (not shown) communicates with the color valve 35. The color valve 35 sends the cleaning air received from an air tank (not shown) to the internal paint path 67 through the connection portion 65.

  The internal paint path 67 sends the cleaning agent and cleaning air received from the color valve 36 and the color valve 35 to the external pipe 17. The external pipe 17 sends the cleaning agent and the cleaning air received from the internal paint path 67 to the solvent paint path 16 via the pipe connection portion 14. The cleaning agent and the cleaning air clean the inner paint path 67, the outer pipe 17, and the solvent paint path 16 in this order.

  The color change valve 30 selects and switches the color valve connected to the internal paint path 67 from among the color valves 31 to 36. For this reason, the color change valve can switch the color of the solvent paint.

  When the color valve is switched, it is necessary to clean the internal paint path 67, the external pipe 17, and the solvent paint path 16 with a cleaning agent and cleaning air. By such cleaning, the solvent paint remaining in each path or pipe can be removed.

  The cleaning agent tank can store thinner as a cleaning agent for solvent paint. From the viewpoint of detergency, thinners include xylene, ethylbenzene, petroleum aromatic hydrocarbons, 1,3,5-trimethylbenzene, isobutyl acetate, butyl acetate, methyl isobutyl ketone, n-butyl alcohol, or 3-methoxy-3. -Methyl-1-butanol is preferred.

  It is well known to those skilled in the art that such thinners require appropriate handling for the safety of painters and the preservation of the surrounding environment. Since the coating apparatus 100 includes the cleaning mechanism for the solvent paint path 16, the solvent paint remaining in the solvent paint path 16 can be washed after the predetermined solvent paint is applied.

  The painting apparatus 100 can include a robot (not shown). The bell main body 10 further includes a robot connection portion 13. The robot connection unit 13 is connected to a robot (not shown). The robot connection unit 13 includes a pipe connection unit 14 on a connection surface with the robot.

  The robot and the bell main body 10 are detachable. The robot includes an external pipe 17 that communicates with the solvent paint path 16 via a pipe connection 14. It is preferable that the outer tube 17 has flexibility that can follow the operation of the robot.

  The solvent coating path 16 is located in the bell main body 10, and thus can have an inflow end 54 that contacts the pipe connection portion 14. The delivery end 55 of the solvent paint path 16 is connected to the rotary atomizing head 20. The external pipe 17 sends the solvent paint 4 received from the internal paint path 67 of the color change valve 30 to the solvent paint path 16.

  The solvent paint path 16 sends the solvent paint 4 received from the outer tube 17 to the rotary atomizing head 20. In each path and pipe, the color paints other than the solvent paint 4 sent out by the color valves 32 to 34 are similarly received and sent.

  Since the coating apparatus 100 includes the outer tube 17, the bell main body 10 can be replaced without replacing the color change valve 30. For this reason, the coating apparatus 100 can smoothly replace the bell main body 10. Further, since the color change valve 30 can be fixed at a predetermined position around the robot or around the robot, damage due to a mechanical action during the operation of the coating apparatus 100 can be prevented.

  The cartridge group 50 is detachably attached to the bell main body 10. The cartridge group 50 includes cartridges 21 to 23. The number of cartridges may be 1 to 3, or 4 or more. In the drawing, the cartridge 21 in the cartridge group 50 is connected to the bell main body 10. The bell body 10 has a connecting surface 51 used for coupling with the cartridge group 50.

  The water-based paint path 15 can have an inflow end 52 on the connection surface 51 by being located in the bell body 10. The cartridge 21 has a paint container 24. The aqueous paint path 15 can be connected to the paint container 24 via the inflow end 52. The paint container 24 can store the water-based paint 1, for example.

  After the cartridge 21 is connected to the bell body 10, the paint container 24 is pressed in the cartridge 21. The coating container 24 whose volume has been shrunk under pressure sends the aqueous coating material 1 to the aqueous coating material path 15 via the inflow end 52. The cover 27 seals the cartridge and prevents the fluid that presses the paint container 24 from leaking out. The paint container 24 is preferably bag-shaped.

  The cartridge 22 includes a paint container 25 that can store the water-based paint 2. The cartridge 22 further includes a cover 28. The cartridge 23 includes a paint container 26 that can store the water-based paint 3. The cartridge 23 further includes a cover 29. The function of each member is the same as that of each member of the cartridge 21. For this reason, the color which the coating apparatus 100 paints can be switched to the color of desired water-based paints 1-3 by replacement | exchange of a cartridge.

  The bell body 10 further has a cleaning path 19. The cleaning path 19 branches off from the water-based paint path 15. The cleaning path 19 is connected to the lumen of the water-based paint path 15 at one end. The cleaning path 19 is connected to the water-based paint path 15 via the trigger valve 12. The cleaning path 19 is connected to the cleaning unit 18 at the other end.

  The trigger valve 12 cuts off the connection between the cleaning path 19 and the water-based paint path 15 and opens the water-based paint path 15. The trigger valve 12 blocks the pipe line between the inflow end 52 and the delivery end 53 of the water-based paint path 15. For this reason, the cleaning path 19 and the delivery end 53 communicate with each other via the trigger valve 12.

  The cleaning unit 18 sends the cleaning agent received from the cleaning valve described later to the cleaning path 19. The cleaning path 19 sends the cleaning agent received from the cleaning unit 18 to the water-based paint path 15 via the trigger valve 12. The cleaning agent cleans the lumen of the water-based paint path 15. The cleaning path 19 is preferably connected in the vicinity of the inflow end 52 in order to reduce the portion in the lumen of the aqueous paint path 15 where the cleaning agent cannot be cleaned.

  From the viewpoint of detergency, aqueous thinner is preferred as the cleaning agent. The aqueous thinner is preferably water mixed with an amine. An aqueous solution of Toyogent (registered trademark) T-SW3 is particularly suitable as an aqueous thinner.

Toyogent T-SW3:
35-45% Ethylene glycol mono-n-butyl ether 10-20% Propylene glycol normal butyl ether 30-40% Isopropyl alcohol 5-10% Isopropanolamine

Toyogent T-SW3 diluted with pure water (85% pure water):
5.3-6.8% Ethylene glycol mono-n-butyl ether 1.5-3.0% Propylene glycol normal butyl ether 4.5-6.0% Isopropyl alcohol 0.8-1.5% Isopropanolamine

  As shown in FIG. 3, the coating apparatus 100 includes a voltage applying device and other conductive members. The other conductive members are electrically connected between the voltage application device and the rotary atomizing head 20. In FIG. 3, description of members having the same reference numerals as those shown in FIG. 2 is omitted.

  In addition, compared with FIG. 2, the solvent coating path 16 is located in the bell main body 10 in the upper side in the figure. Such illustration is for convenience of explanation and does not indicate a desirable position of the solvent coating path 16. In the present embodiment, the solvent paint path 16 has no particular position limitation as long as it is located within the bell main body 10.

  The voltage application device includes a cascade (high voltage generator) 75, low voltage cables 76 and 77, and a high voltage controller 78. Other conductive members are an air motor 70, a terminal 73, and a high voltage cable 74.

  The air motor 70 is connected to the rotary atomizing head 20. The air motor 70 includes a terminal 73. The terminal 73 is connected to the high voltage cable 74. The high voltage cable 74 is connected to the cascade 75.

  The cascade 75 is connected to the low voltage cable 76. The low voltage cable 76 and the low voltage cable 77 are a series of low voltage cables. The low voltage cable 77 is connected to the high voltage controller 78. According to the input to the high voltage controller, the voltage application device applies a voltage directly to the rotary atomizing head 20. The rotary atomizing head 20 charges the water-based paint and the solvent paint using the received voltage.

  In a preferred aspect of this embodiment, the color change valve 30 is not connected to a water-based paint tank. In such a case, since the solvent paint has an insulating property, the charge does not leak to the color change valve 30 even if it is charged. Since the insulating cartridge supplies the water-based paint, the water-based paint does not leak electric charge even when charged.

  As shown in FIG. 4, the coating apparatus 100 further includes a cleaning valve 80, a connection portion 81, and an external pipe 82. 4, description of members having the same reference numerals as those in FIG. 2 is omitted. The cleaning valve 80 includes a branch portion 83 and valves 84 and 85.

  The cleaning unit 18 is detachably connected to the cleaning path 19 via the connection portion 81. Further, the docking unit including the cleaning unit 18 may be connected to the connection portion 81 during cleaning. The docking unit includes a cleaning valve 80, a cleaning unit 18, and an external pipe 82.

  The valve 84 sends the cleaning agent received from a cleaning agent tank (not shown) to the branch portion 83. The branch portion 83 sends the cleaning agent received from the valve 84 to the outer pipe 82. The outer pipe 82 sends the cleaning agent received from the branch portion 83 to the cleaning unit 18.

  The valve 85 sends cleaning air to a conduit that connects the branch portion 83, the outer pipe 82, the cleaning unit 18, the connection portion 81, the cleaning path 19, the trigger valve 12, the water-based paint path 15, and the rotary atomizing head 20.

  As shown in FIG. 5, the bell main body 10 has a hollow rotating shaft 114 connected to the rotary atomizing head 20. Description of members having the same reference numerals as those shown in FIGS. 2 to 4 in FIG. 5 is partially omitted. The water-based paint path 15 and the solvent paint path 16 respectively penetrate the hollow rotary shaft 114.

  The delivery end 53 of the water-based paint path is in contact with an end surface 117 connected to the rotary atomizing head 20 of the hollow rotary shaft 114 and a space 119 surrounded by the inner wall 120 of the rotary atomizing head 20. The delivery end 55 of the solvent paint path also contacts the space 119.

  FIG. 5 shows the tip of the bell body 10 on the rotary atomizing head 20 side. A resin case 111 is located at the tip of the bell body 10. The resin case 111 has a cylindrical shape with a large opening on the rotary atomizing head 20 side and extending in the axial direction. A radial bearing 112 and a thrust bearing 113 are located inside the resin case 111. The pattern air nozzle part 177 is in contact with the rotary atomizing head side of the resin case 111.

  A hollow rotary shaft 114 is located inside the radial bearing 112. A flange portion 114 a that bulges toward the outer circumferential direction is located on one side of the hollow rotary shaft 114. The turbine blade 115 is located on the outer peripheral surface of the flange portion 114a. The radial bearing 112 holds the cylindrical portion 114b of the hollow rotary shaft 114. The thrust bearing 113 holds the flange portion 114a.

  An air nozzle 116 is located inside the resin case 111. The air nozzle 116 ejects high-speed air toward the turbine blade 115. When the air nozzle 116 ejects high-speed air, the hollow rotary shaft 114 rotates at high speed around the axis. The thrust bearing 113 holds the side surface of the flange portion 114a, thereby preventing the hollow rotary shaft 114 from being displaced in the axial direction due to the ejection of air from the air nozzle 116.

  The air motor 70 shown in FIG. 3 includes a thrust bearing 113, a flange portion 114a, a turbine blade 115, an air nozzle 116, a radial bearing 112, and a cylindrical portion 114b. An aqueous paint path 15 and a solvent paint path 16 are located in the hollow 114e.

  For example, the air motor 70 rotates the rotary atomizing head 20 at 25,000 to 40,000 rpm in order to give a preferable atomization state to the paint. As the rotary atomizing head 20 rotates at a high speed, the cleaning agent attached to the rotary atomizing head 20 is also scattered.

  A male screw portion 114c is located at the tip of the hollow rotary shaft 114 on the side that does not contact the rotary atomizing head. The tapered surface 114d of the hollow rotary shaft 114 is continuous with the male screw portion 114c. The rotary atomizing head 20 is screwed into the male screw portion 114c.

  When the rotary atomizing head 20 is completely screwed with the male screw portion 114c, the rotary atomizing head 20 is sufficiently adhered to the tapered surface 114d. The male threaded portion 114c and the tapered surface 114d prevent rattling that occurs between the rotary atomizing head 20 and the hollow rotary shaft 114 during the painting operation.

  The rotary atomizing head 20 has a partition wall 20a. A conical protrusion 20b is located at the center of the partition wall 20a. The protruding portion 20b protrudes toward the hollow rotary shaft 114 side. The cleaning hole 20c penetrates the partition wall 20a from the tapered surface of the protrusion 20b. A paint passage 20d is located on the outer periphery of the partition wall 20a. The paint passage 20d penetrates the partition wall 20a.

  The aqueous paint path 15 includes a paint nozzle 125, a paint path 132, and a paint hose 162. The coating material nozzle 125 passes through the hollow rotating shaft 114 in the vertical direction in the drawing through the hollow 114e. The paint nozzle 125 protrudes from the end wall of the hollow rotary shaft 114 at the end of the hollow rotary shaft 114 opposite to the rotary atomizing head 20. An end of the paint nozzle 125 is connected to a paint passage 132 formed in the resin case 111.

  The solvent paint path 16 includes a paint nozzle 126, a paint path 133, and a paint hose 163. The coating material nozzle 126 passes through the hollow rotating shaft 114 in the vertical direction in the drawing through the hollow 114e. The paint nozzle 126 protrudes from the end wall of the hollow rotary shaft 114 at the end of the hollow rotary shaft 114 opposite to the rotary atomizing head 20. An end portion of the paint nozzle 126 is connected to a paint passage 133 of the solvent paint passage 16 formed in the resin case 111.

  The paint passage 132 is connected to the cartridge or cleaning passage 19 coupled to the bell body 10 via the paint hose 162 of the water-based paint passage 15. The paint passage 133 is connected to the color change valve 30 communicating with the paint tank and the cleaning agent tank via the paint hose 163 of the solvent paint path 16.

  The high voltage cable 74 applies a voltage to the terminal 73. The terminal 73 applies a voltage to the rotary atomizing head 20 via the air motor 70 having conductivity. The rotary atomizing head 20 applies a voltage to the water-based paint and the solvent paint to be charged. The rotary atomizing head 20 further turns the water-based paint and solvent paint into charged atomized particles.

  The particles of each paint fly toward the object to be coated by the pattern air ejected from the pattern air nozzle part 177. The object to be coated attracts paint particles by electrostatic force. The coating apparatus efficiently applies the coating material to the object to be coated by the pushing effect of the pattern air and the electrostatic force.

  In a preferred embodiment of the bell main body 10, it is connected to a space 119 that passes through the hollow rotary shaft 114 and is connected to the rotary atomizing head 20 of the hollow rotary shaft 114 and the inner wall 120 of the rotary atomizing head 20. Does not have a cleaning nozzle. In a further preferred aspect of the bell body 10, there is no cleaning nozzle that penetrates the hollow rotating shaft 114.

  Since the coating apparatus 100 includes the cleaning path 19 as described above, the cleaning agent cleans the delivery end of the water-based paint path 15. Since the coating apparatus 100 includes the color change valve 30 communicating with the cleaning agent tank as described above, the cleaning agent cleans the delivery end of the solvent paint path 16. Therefore, the above-described cleaning nozzle is not necessary.

  Since the coating apparatus 100 includes the cartridge group 50 as described above, the water-based paint path 15 can supply a plurality of water-based paints to the rotary atomizing head 20. In addition, the cleaning path 19 supplies the cleaning agent to the water-based paint path 15 every time the application of each water-based paint is completed. For this reason, it is prevented that the coating apparatus 100 paints the water-based paint mixed with different water-based paints in the water-based paint path 15.

  Since the coating apparatus 100 includes the color change valve 30 as described above, the solvent coating path 16 can supply a plurality of solvent coatings to the rotary atomizing head 20. In addition, the color change valve 30 communicating with the cleaning agent tank supplies the cleaning agent to the solvent coating path 16 every time the application of each solvent coating is completed. For this reason, it is possible to prevent the coating apparatus 100 from applying a solvent paint mixed with a different solvent paint in the solvent paint path 16.

The coating apparatus 100 can use various water-based paints and solvent paints properly even if the pipes penetrating the hollow rotary shaft are only the water-based paint path 15 and the solvent paint path 16. Accordingly, the coating apparatus 100 includes the air motor 70 that is simplified as described above. For this reason, even if the coating apparatus 100 repeats the painting operation, failure is unlikely to occur.
[Operation]

  The operation of the coating apparatus and the coating method of this embodiment will be described by focusing on the paint switching method. The method for switching between the water-based paint and the solvent paint of this embodiment is as follows. For example, the coating apparatus 100 of FIG. 2 coats the water-based paint 3 on the object to be coated. Next, the aqueous thinner cleans the aqueous paint 3 remaining in the aqueous paint path 15 and the rotary atomizing head 20.

  The solvent paint path 16 sends the solvent paint 4 received from the color change valve to the rotary atomizing head 20. The coating apparatus 100 sprays the solvent paint 4 on the object to be coated and coats it. The coating apparatus 100 completes the coating of the object to be coated by laminating a water-based paint and a solvent paint on the surface of the non-painted object according to a predetermined procedure.

[Description of effects]
1. Reduction of cleaning time In general, painting of automobiles requires intermediate coating, base coating, and clear coating processes. In order to reduce the environmental load, the intermediate coating and the base coating are preferably water-based coatings. In order to improve the aesthetics and weather resistance of the painted surface, the clear coating is preferably a solvent paint.

  In a small-scale coating line, in order to increase production efficiency, it is preferable to apply both water-based paint and solvent paint in the same process using the same coating apparatus. Further, as will be described later, the color change valve is not suitable for electrostatic coating of a water-based paint. For this reason, it is preferable to apply a water-based paint and a solvent paint with the same coating apparatus provided with a cartridge as shown in FIG.

  FIG. 6 shows a coating apparatus 200 according to the first comparative embodiment. Description of members having the same reference numerals as those in FIG. 2 in FIG. 5 is partially omitted. The coating apparatus 200 includes a water-based paint cartridge group 50 and a solvent paint cartridge group 40.

  The cartridge group 40 is detachable from the bell body 10. The cartridge group 40 includes cartridges 41 and 42. The cartridge 41 includes a paint container 44 that can store the solvent paint 4. The cartridge 41 further includes a cover 47.

  The cartridge 42 includes a paint container 45 that can store the solvent paint 5. The cartridge 42 further includes a cover 29. The function of each member is the same as that of each member of the cartridge 21. For this reason, the color which the coating apparatus 200 paints can be switched to the color of the desired solvent paint 4-5 by replacement | exchange of a cartridge.

  In the first comparative embodiment, the feed tube provided in the bell main body is only one common paint path 56 through which the water-based paint and the solvent paint flow. This feature is different from the above embodiment in which the water-based paint path and the solvent paint path are separated in the bell body.

  The coating method of the first comparative form is as follows. Each cartridge is filled with water-based paints 1-3 and solvent paints 4-5. Next, the cartridge 21 is coupled to the bell main body 210.

  Next, the common paint path 56 sends the aqueous paint 1 received from the cartridge 21 to the rotary atomizing head 20. The coating apparatus 200 sprays the water-based paint 1 onto the object to be coated and coats it. Next, the cleaning path 59 sends the aqueous thinner and cleaning air received from the cleaning unit 58 to the common paint path 56.

  The common paint path 56 sends the aqueous thinner and cleaning air received from the cleaning path 59 to the rotary atomizing head 20. The aqueous thinner cleans the common paint path 56 and the rotary atomizing head 20. The cleaning air volatilizes the aqueous thinner remaining in the common paint path 56 and the rotary atomizing head 20.

  The method for switching between the water-based paint and the solvent paint is as follows. For example, the coating apparatus 200 applies the water-based paint 3 to the object to be coated. Next, the aqueous thinner cleans the aqueous paint 3 remaining on the common paint path 56 and the rotary atomizing head 20.

  Next, the cleaning path 59 sends the solvent thinner and cleaning air received from the cleaning unit 58 to the common paint path 56. Here, the solvent thinner replaces the aqueous thinner remaining in the common paint path 56 and the rotary atomizing head 20.

  Next, the cartridge 23 is detached from the bell main body 210. Next, the cartridge 41 is coupled to the bell body 210. Next, the common paint path 56 sends the solvent paint 4 received from the cartridge 41 to the rotary atomizing head 20. The coating apparatus 200 sprays the solvent paint 4 on the object to be coated and coats it.

  On the other hand, as shown in FIG. 2, in this embodiment, the feed tube has a plurality of paths divided into an aqueous paint path and a solvent paint path up to the rotary atomizing head. For this reason, the site | part used by both water-based coating and solvent coating, ie, a mixing part, is only in the rotary atomization head.

  The switching method of the first comparative form requires replacement with a solvent thinner and a cleaning step associated therewith. Even if the color change cleaning is performed after the water-based paint is applied, a small amount of water-based paint remains in the common paint path 56. Aggregates can occur when the solvent paint passes through the common paint path 56.

  On the other hand, the switching method of this embodiment does not require replacement with a solvent thinner and a cleaning process associated therewith. Therefore, the switching method of the above embodiment has an effect of shortening the cleaning time and the total coating time.

2. Prevention of Aggregate Generation The coating apparatus shown in Patent Document 1 or FIG. 6 has a common pipe path or a common paint path for water-based paint and solvent paint. In such a common pipe, a water-based paint and a solvent paint are mixed to produce an aggregate. On the other hand, the coating apparatus of this embodiment has the water-based paint path | route and solvent paint path | route which became separate. For this reason, the coating apparatus of this embodiment has an effect that the solvent or the paint hardly generates aggregates.

  The water-based paint of this embodiment is a resin emulsion paint. Since the resin particles forming the coating film have OH groups or COOH groups on the surface, they have hydrophilicity. Correspondingly, a solvent having hydrophilicity, for example, an aqueous thinner, is used as the cleaning agent for the aqueous paint.

  When a hydrophobic liquid, that is, a solvent paint or solvent thinner is mixed in the water-based paint, OH groups on the surface of the resin particles react with these. For this reason, the OH group is detached from the particle surface. As a result, each particle cannot be maintained in a dispersed state and aggregates. The inventors have found that it is desirable that the delivery route of the water-based paint and its cleaning agent and the delivery route of the solvent paint and its cleaning agent are separated in the coating apparatus.

  The state of the paint, that is, the form of the polymer in the paint is a standard for classifying the paint. There are three major groups of paints: solution, dispersion, and powder. Dispersed forms include those in which polymer particles are dispersed and emulsified. In the dispersion type paint, the main component for forming a film is not dissolved in the solvent.

  The dispersed form is also called an emulsion type. The dispersion form includes a NAD (non-aqueous dispersion form) type in which polymer particles are dispersed in an aliphatic hydrocarbon solvent. The polymer is dispersed in the solvent in both the dispersed form and the non-aqueous dispersed form. For this reason, even if the molecular weight of the polymer is large, the viscosity does not increase, and the ratio of the solid content during coating can be increased.

  There are two types of water-based paints: water-soluble (solution-type paints) and emulsion paints. Water-based paints can be diluted with water. Most of the paint resins are synthetic resins made from petroleum. For this reason, it does not dissolve in water.

  Therefore, it is preferable that the water-based paint containing the resin for coating (polymer) is an emulsion in which the particulate polymer is dispersed in water, or the polymer is water-soluble, that is, water-soluble.

  When the polymer of the water-soluble paint is ionized in water containing an electrolyte, the polymer dissolves in water. Utilizing such properties, water-soluble paints are used in automobile coatings as electrodeposition primers.

  Emulsion paint is also referred to as emulsion paint or latex paint. Emulsion paints are used in construction site painting. In the synthetic resin emulsion paint, a synthetic resin having a particle size of about 0.5 to 1 μm is dispersed in water to form an emulsified state. Within the synthetic resin emulsion paint, the synthetic resin is not dissolved in water and is therefore not a solute.

  Emulsion paint does not necessarily refer to water-based paint in general. As described above, the water-based paint includes a solvent-type paint. The emulsion of the emulsion paint indicates the state of the paint. Therefore, the coating apparatus of this embodiment is particularly suitable for the application of a coating method using an emulsion paint.

3. Atomization of paint The coating apparatus of this embodiment has a rotary atomizing head. The coating apparatus of this embodiment atomizes a paint with a rotary atomizing head. An air atomizing gun is known as a means for atomizing paint. As in the present embodiment, it is difficult for the air atomizing gun to include an aqueous paint path and a solvent paint path that are separated from each other up to the atomization section.

  As shown in FIG. 7, the air atomizing gun of the second comparative embodiment has an air cap 203 as an atomizing portion. The paint nozzle located at the center of the air cap discharges paint. The paint in the figure is a solvent paint 204.

  The atomized air 205 is ejected from a slit around the paint nozzle and atomizes the solvent paint 204. The pattern air 213 collects the atomized paint in an ellipse 214. The air atomizing gun applies the mist of the solvent paint 204 gathered in an elliptical shape to the object to be coated, thereby coating the object.

  FIG. 8 shows a cross section of the discharge part of the air cap 203 of the second comparative embodiment. The air cap 203 has a paint nozzle 234 and an air nozzle 235. The paint path 231 is located inside the paint nozzle 234. The slit-shaped air path 212 is located inside the air nozzle 235 and outside the paint nozzle 234. The paint path 231 discharges the solvent paint 204.

  The air path 212 discharges atomized air 205. The center of the paint path 231 coincides with the center of the air path 212. For this reason, the atomized air 205 is blown out uniformly around the discharge port of the paint nozzle 234. Therefore, the solvent paint 204 is atomized normally.

  The air atomizing gun has only one paint nozzle. For this reason, in a coating method in which the water-based paint and the solvent paint are switched and used, such an air atomizing gun needs to have a common pipe line as in the coating apparatus described in Patent Document 1, for example. The paint nozzle 234 discharges the aqueous paint or solvent paint received from the common pipe.

  As described above, the common pipe line of the water-based paint and the solvent paint needs to be replaced with a cleaning agent when the paint is switched. On the other hand, in the coating apparatus of this embodiment, the water-based paint path and the solvent paint path are separated. For this reason, the coating apparatus does not require a replacement operation with a cleaning agent when the paint is switched.

  As shown in FIG. 9, the air atomizing gun of the third comparative embodiment includes an aqueous paint path and a solvent paint path that are separated from each other up to the atomizing section as in the present embodiment. 9, description of members having the same reference numerals as those in FIG. 8 is omitted.

  The air cap 203 has a paint nozzle 236 and an air nozzle 235. The water-based paint path 232 is one opening provided in the paint nozzle 236. The solvent paint path 233 is the other opening provided in the paint nozzle 236. The solvent paint 204 is discharged from the solvent paint path 233.

  The center of the solvent paint path 233 and the center of the air path 212 do not coincide. For this reason, the atomized air 205 cannot be evenly blown around the discharge port of the solvent paint path 233 of the paint nozzle 236. Therefore, the air atomizing gun cannot properly atomize the solvent paint 204.

  On the other hand, the coating apparatus of this embodiment atomizes a paint with a rotary atomizing head instead of an air nozzle. As shown in FIG. 5, the rotary atomizing head 20 of the present embodiment includes a delivery end 53 of the aqueous paint path 15 or a delivery end 55 of the solvent paint path 16 as a paint discharge port.

  The delivery end 53 and the delivery end 55 are not located on the rotation axis of the rotary atomizing head 20. However, since the rotary atomizing head 20 rotates at a high speed, the coating spreads evenly on the surface of the partition wall 20a or the inner wall 120 due to centrifugal force. For this reason, the coating apparatus 100 can discharge the atomized paint evenly even if the position of the discharge port of the paint is shifted from the rotation axis of the rotary atomizing head 20.

4). Electrostatic coating As shown in FIG. 3, the coating apparatus 100 of the present embodiment includes a voltage application device that is electrically connected to the rotary atomizing head 20. The water-based paint is conductive. For this reason, when water-based paint is supplied through the color change valve, electric charge leaks through the color change valve. If the charge of the water-based paint leaks, the coating apparatus cannot electrostatically paint the water-based paint.

  In contrast, the coating apparatus may include an external electrode. The external electrode is indirectly charged after atomization of the uncharged water-based paint. For this reason, since the coating apparatus does not need to charge the water-based paint in the paint path, the water-based paint can be supplied by the color change valve.

  However, it is difficult for the external electrode to efficiently charge the paint. For this reason, compared with the coating apparatus provided with an external electrode, the coating apparatus of this embodiment can apply | coat efficiently the coating material which has a weather resistance and is excellent in aesthetics.

5. Summary That is, in the coating apparatus of the present embodiment, (1) the water-based paint path and the solvent paint path are separated to the respective discharge ports, and (2) the rotary atomizing head faces the discharge ports. For this reason, the coating apparatus has a special effect that a cleaning agent replacement step is not required when switching between the water-based paint and the solvent paint.

  Further, the water-based paint route and the solvent paint route are not communicated with each other in the coating apparatus. For this reason, it is possible to prevent the solvent paint from going up to the aqueous paint path. Further, the coating apparatus can prevent the aqueous paint from going up to the solvent paint path.

  Further, in the coating apparatus, (3) the water-based paint path is connected to the cartridge and the cleaning path, and (4) the solvent paint path is connected to the paint tank and the cleaning tank via the color change valve. For this reason, this coating apparatus does not necessarily need to be provided with a paint path and a discharge port for each paint. Therefore, the structure of the coating apparatus is simplified, and the special effects of improving the durability of the coating apparatus are achieved.

  Further, in the coating apparatus, since the cartridge supplies the water-based paint and the color change valve supplies the solvent paint, (5) the coating apparatus may include a voltage application device that directly applies a voltage to the rotary atomizing head. it can. For this reason, the coating apparatus of this embodiment can be painted efficiently.

  Also, changing the cartridge, attaching and detaching the cartridge, and putting in and out the paint stock require a complicated robot system. On the other hand, as described above, the coating apparatus does not require (6) a solvent paint cartridge. For this reason, the coating apparatus can have a more simplified robot system.

  In addition, this invention is not limited to the said embodiment, It is possible to change suitably in the range which does not deviate from the meaning.

  In the above embodiment, the coating apparatus includes one water-based coating path. In contrast, in a variation of the embodiment, the coating apparatus may include two or more water-based paint paths. The coating device may deliver one aqueous paint to the rotary atomizing head via one aqueous paint path. Furthermore, the coating apparatus may deliver other water-based paints to the rotary atomizing head via other water-based paint paths.

  In the case where agglomerates may be generated from one mixed aqueous paint and another aqueous paint, the coating apparatus can suppress the generation of such agglomerates. Each cartridge for containing a water-based paint may have a different opening position for each corresponding water-based paint path. Moreover, a trigger valve may distribute a paint to each water-based paint path | route for every corresponding paint.

  In the above embodiment, the water-based paint path received the water-based paint cleaning agent from the cleaning path. In contrast, in a variation of the embodiment, the water-based paint path may receive a water-based paint cleaner from the cartridge. One cartridge in the cartridge group may have only a cleaning agent container for storing the cleaning agent. Some or all of the cartridges in the cartridge group may have a cleaning agent container and a paint container. A coating apparatus provided with such a cartridge may not include a cleaning path. For this reason, the structure of the coating apparatus is simplified.

  In the above embodiment, the high voltage cable is connected to the terminal of the air motor. On the other hand, in a variation of the embodiment, the high voltage cable may be connected to the rotating part or the radial bearing.

  One of the applications of the present embodiment is a method for manufacturing a vehicle body, which includes a painting process in which a vehicle body before painting is painted by the above-described method to form a painted vehicle body. By such a method, it is possible to efficiently produce a car body having excellent aesthetics and weather resistance.

  One of the applications of the present embodiment is an automobile including the above-described painting process and an assembling process for coupling a painted automobile body with automobile parts including driving parts, control parts, and interior parts. It is a manufacturing method. By such a method, an automobile having excellent aesthetics and weather resistance can be produced efficiently.

  One of the applications of this embodiment is a method of repainting an automobile, which includes a repainting step of painting a part or all of a painted vehicle body of the automobile by the above-described method. Such a method can efficiently repair a car whose paint has been damaged or deteriorated without impairing its beauty and weather resistance.

  In the present embodiment, the painting apparatus and the painting method are shown by taking the automobile body as an example, but the object to be painted is not limited to the automobile. For example, the present invention may be applied to the coating of aircraft, machine tools, transport machines, home appliances, office equipment, building materials, and the like.

DESCRIPTION OF SYMBOLS 10 Bell main body 15 Water-based paint path | route 16 Solvent paint path | route 17 Outer pipe | tube 19 Cleaning path | route 20 Cartridge 22 Cartridge 23 Cartridge 24 Paint container 25 Paint container 26 Paint container 30 Color change valve 51 Connecting surface 52 Inflow end 53 Delivery end 55 Sending end 75 Cascade (part of voltage application device)
76 Low voltage cable (part of voltage application device)
77 Low voltage cable (part of voltage application device)
78 High voltage controller (part of voltage application device)
DESCRIPTION OF SYMBOLS 100 Coating apparatus 114 Hollow rotating shaft 117 End surface 119 Space 120 Inner wall

Claims (8)

A bell body having a rotary atomizing head;
An aqueous paint path connected to the rotary atomizing head;
A coating apparatus comprising: a solvent paint path connected to the rotary atomizing head without being connected to the water-based paint path. A voltage application device in electrical communication with the rotary atomizing head;
A cartridge connectable to the water-based paint path;
A color change valve located outside the bell body and connected to the solvent paint path;
The coating apparatus according to claim 1, further comprising: An outer pipe connected to the solvent paint path and the color change valve;
A cleaning agent tank connected to the color change valve;
The solvent paint path is located in the bell body and communicates with the cleaning agent tank via the outer pipe and the color change valve.
The coating apparatus according to claim 2. The cartridge is detachable from the bell body,
The coating apparatus according to claim 2, wherein the water-based paint path has an inflow end that is located in the bell main body and is connectable to a paint container of the cartridge via a connection surface of the bell main body and the cartridge. . The bell body further has a cleaning path branched from the water-based paint path,
The coating apparatus according to claim 1, wherein the cleaning path is connected to a lumen of the water-based paint path.   The bell main body further includes a hollow rotary shaft connected to the rotary atomizing head, but an end surface that penetrates the hollow rotary shaft and connects to the rotary atomizing head of the hollow rotary shaft, and the rotary atomizing head The coating apparatus in any one of Claims 1-5 which does not have a washing nozzle connected to the space enclosed by the inner wall of.   The said bell main body further has the hollow rotating shaft connected to the said rotary atomization head, However, The coating apparatus in any one of Claims 1-5 which does not have a washing nozzle which penetrates the said hollow rotating shaft. The water-based paint path and the solvent paint path each pass through the hollow rotary shaft, respectively, and each have a delivery end,
The delivery ends of the water-based paint path and the solvent paint path are in contact with an end face connected to the rotary atomizing head of the hollow rotary shaft and a space surrounded by an inner wall of the rotary atomizing head, respectively. The coating equipment described.

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