JP5086679B2 - Electrostatic coating equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic coating apparatus having an insulation mechanism having improved reliability and capable of reducing the cost. <P>SOLUTION: The electrostatic coating apparatus 10 includes a cylinder 18 capable of filling and pushing out an insulating coating material and a color changing valve 14 for supplying the coating material to the cylinder 18 and is provided with the insulation mechanism 16 between the cylinder 18 and the color changing valve 14. The insulation mechanism 16 is provided with insulating material-made tubes 32, 34, a first switching valve 36 connected to the end part of each tube 32, 34 in the color changing valve 14 side and a second switching valve 38 connected to the end part of each tube 32, 24 in the cylinder 18 side, wherein a discharge passage 60 communicating with a waste discharge side is connected to the first switching valve 36. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electrostatic coating apparatus that performs electrostatic coating using a conductive paint.

  In general, an electrostatic coating apparatus having a cylinder capable of filling and extruding paint, extruding the paint filled in the cylinder from a paint supply valve (color changing valve), and applying and discharging a high voltage from a paint gun is known. ing.

  In this type of electrostatic coating apparatus, an insulating mechanism is interposed between the paint supply valve and the cylinder, and the paint supply valve and the cylinder are electrically insulated. This prevents voltage leakage from the cylinder or paint gun to the paint supply valve during painting, thereby realizing good electrostatic painting.

  Usually, the insulating mechanism is provided with a tube made of an insulating material. When painting, first, the paint from the paint supply valve is filled into the cylinder through the tube. Next, after flowing the cleaning liquid from the cleaning valve from one end side to the other end side of the tube, the inside of the tube is dried by flowing air to ensure insulation performance.

  The present applicant has proposed an electrostatic coating apparatus in which a height difference is provided between one end side and the other end side of a tube made of an insulating material (Patent Document 1). In this case, even when air drying after cleaning is insufficient, it is possible to effectively prevent insulation failure caused by the cleaning liquid remaining on the cleaning valve side of the tube.

JP 2000-354796 A

  By the way, in the conventional electrostatic coating apparatus, a single insulating tube is formed, and a downstream switching valve connected to the downstream end of the tube is connected to a discharge path communicating with the paint discharge side. Has been. Therefore, if dirt due to paint or cleaning liquid adheres to the discharge path, insulation failure may occur through the discharge path even when insulation by the tube is secured. It may be difficult to ensure reliability. For this reason, periodic maintenance such as replacement of the discharge path is required. However, since the discharge path is considerably longer than the tube, the replacement cost is high. It is also necessary to have spare parts for the discharge channel.

  Furthermore, since the said tube is comprised by 1 piece, it is easy to restrict | limit supply amount, it is difficult to improve the filling speed | rate of the coating material to a cylinder, and becomes a cause which reduces the efficiency of a coating process.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to provide an electrostatic coating apparatus capable of improving the reliability of an insulating mechanism and reducing the cost. Another object of the present invention is to provide an electrostatic coating apparatus capable of speeding up filling of a paint into a cylinder and improving the efficiency of a painting process.

  An electrostatic coating apparatus according to the present invention includes a cylinder capable of filling and extruding paint and a paint supply valve for supplying conductive paint to the cylinder, and an insulating mechanism is provided between the cylinder and the paint supply valve. In the electrostatic coating apparatus provided, the insulating mechanism includes a plurality of tubes made of an insulating material, a first switching valve connected to an end of each tube on the paint supply valve side, and the cylinder of each tube And a second switching valve connected to an end portion on the side, wherein the first switching valve is connected to a discharge path communicating with the discharge side of the waste liquid.

  According to such a configuration, after the cylinder is filled with the paint and the insulation by the insulation mechanism is ensured, the discharge path is connected to the first switching valve side to which no voltage is applied. It is possible to effectively prevent the occurrence of voltage leakage from the discharge path to the waste liquid storage tank during painting. Further, even when dirt due to paint or the like adheres to the discharge path, the discharge path is surely electrically insulated, so that the reliability of the apparatus can be improved. In addition, as described above, the discharge path can be used sufficiently as long as it is capable of discharging cleaning waste liquid, etc., so that special maintenance is not required, and replacement of a discharge path that is normally configured to be a considerably long length Cost can be reduced.

  Furthermore, when filling the cylinder with paint, for example, the paint can be supplied using two tubes, so the paint filling speed can be greatly improved, Efficiency can be improved.

  In addition, when the path communicating with the waste liquid discharge side is connected only to the first switching valve side than the tube, the insulation mechanism ensures the insulation from the second switching valve of the insulation mechanism. Since there is no path connected to the outside on the cylinder side, voltage leakage can be prevented more reliably, and the reliability of the apparatus can be further improved.

  Furthermore, the insulating mechanism includes a cleaning valve, and a cleaning path communicating with the cleaning valve is connected to the first switching valve, and the inside of the tube is cleaned to ensure insulation in the insulating mechanism. In this case, the cleaning liquid from the cleaning valve flows from the first switching valve to the second switching valve through one tube, and from the second switching valve to the first switching valve through the other tube. It is preferable to return to the valve and discharge from the first switching valve to the discharge passage because insulation of the insulating mechanism can be secured easily and quickly.

  According to the present invention, the discharge path is connected to the first switching valve side to which no voltage is applied in the state in which the cylinder is filled with the paint and the insulation by the insulating mechanism is ensured. Therefore, it is possible to effectively prevent a voltage leak from occurring to the waste liquid storage tank and improve the reliability of the apparatus. In this case, since the discharge path can be sufficiently used as long as the cleaning waste liquid or the like can be discharged, special maintenance is not required and replacement cost can be suppressed.

  Further, according to the present invention, when the paint is filled into the cylinder, for example, the paint can be supplied using two tubes, so that the paint filling speed can be greatly improved. The efficiency of the entire painting process can be improved.

  Hereinafter, preferred embodiments of an electrostatic coating apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram of an electrostatic coating apparatus 10 according to an embodiment of the present invention. The electrostatic coating apparatus 10 is an apparatus that is mounted on, for example, an industrial robot (not shown) and discharges a predetermined color paint from a coating gun 12 to perform electrostatic coating on the body of an automobile. As the paint, a water-based paint which is a conductive paint is used.

  The electrostatic coating apparatus 10 includes a color change valve (paint supply valve) 14 that supplies paint of a predetermined color to a paint gun 12 from a paint supply source (not shown) that supplies each color paint at a high pressure, and the color change valve. And an insulating mechanism 16 provided in the middle of a path through which the paint is introduced from 14 to the coating gun 12. A cylinder 18 capable of filling and extruding paint is interposed between the insulating mechanism 16 and the coating gun 12. The cylinder 18 is filled with, for example, one body of paint, and functions to supply and discharge the paint stably (constantly) to the paint gun 12.

  The color change valve 14 supplies a plurality of paint valves 20 corresponding to each color paint, a cleaning liquid valve (water valve) 22 that supplies water (W) that is a cleaning liquid for water-based paint, and air (A) for drying. A switching valve device connected to a drying valve (air valve) 26 is configured. The paint supply source is connected to each paint valve 20, and when the paint valve 20 corresponding to a predetermined color is opened, the paint of the corresponding paint supply source is passed through the insulating mechanism 16 from the first supply path 28. It is supplied to the cylinder 18.

  The insulating mechanism 16 is disposed between the color change valve 14 and the cylinder 18. The insulating mechanism 16 includes two tubes 32 and 34 made of an insulating material, a first switching valve 36 connected to the end of the tubes 32 and 34 on the color change valve 14 side, and the tubes 32 and 34. The second switching valve 38 is connected to the end portion on the cylinder 18 side. The first switching path 36 is connected to the first supply path 28, and the second switching valve 38 is connected to a second supply path 40 that is a path for supplying paint to the cylinder 18. Further, the insulating mechanism 16 is a valve device in which a cleaning liquid valve 42 that supplies water (W) for cleaning the tubes 32, 34, and the drying valve 44 that supplies air (A) for drying are connected. A cleaning valve 46 is provided.

  In the case of this embodiment, the said 1st switching valve 36 is comprised as a switching valve apparatus comprised by the four valves 48-51. Ends of the tubes 32 and 34 on the color change valve 14 side (upstream side when the cylinder 18 is filled with paint) are connected to the valves 48 and 49, respectively. The color change valve 14 side of the valves 48 and 49 communicates with each other via a path 54 and is connected to the secondary side (tubes 32 and 34 side, downstream side) of the valves 50 and 51 via the path 54. ing. A first supply path 28 from the color change valve 14 is connected to the valve 50, and a cleaning path 56 from the cleaning valve 46 is connected to the valve 51.

  The valve 48 is configured as a three-way valve, and is further connected to a discharge path 60 communicating with a waste liquid storage tank (dump) 58 on the waste liquid discharge side (washing waste liquid discharge side). That is, the valve 48 is in a state in which the path 54 and the tube 32 are in communication (in the direction of arrow X1 in FIG. 1), a state in which the tube 32 and the discharge path 60 are in communication (in the direction of arrow X2 in FIG. 1), and a fully closed state. Switching is possible.

  On the other hand, the said 2nd switching valve 38 is comprised as a switching valve apparatus comprised by the three valves 61-63. The ends of the tubes 32 and 34 on the cylinder 18 side (downstream side when the cylinder 18 is filled with paint) are connected to the valves 61 and 62, respectively. The cylinders 18 side of the valves 61 and 62 communicate with each other via a path 64 and are connected to the primary side (tubes 32 and 34 side, upstream side) of the valve 63 via the path 64. A second supply path 40 to the cylinder 18 is connected to the valve 63.

  The valve 61 is configured as a three-way valve, and is further connected to a return path 66 through which water and paint (cleaning waste liquid) after the inside of the coating gun 12 described later flows. That is, the valve 61 is in a state in which the tube 32 and the path 64 are communicated (in the direction of arrow Y1 in FIG. 1), a state in which the return path 66 and the tube 32 are in communication (in the direction of arrow Y2 in FIG. 1), and a fully closed state. Switching is possible.

  In such an insulating mechanism 16, it is preferable that the tubes 32 and 34 have the same diameter and the same scale. This is because it is easy to secure and manage spare parts for replacement, and it is possible to reduce costs. The tubes 32 and 34 may be made of an insulating material. However, in consideration of resistance to paint and weather resistance, those made of fluororesin are preferable, and examples thereof include PTFE (tetrafluoroethylene resin).

The cylinder 18 has a piston 70 that is driven forward and backward by a motor 68. When the motor 68 is driven by a control means (not shown) and the piston 70 moves backward, the paint from the second supply path 40 is filled into the cylinder 18, and when the piston 70 moves forward, the coating gun 12 passes through the third supply path 72. To supply paint. Motor 6-8 may be performed using a servo motor to easily and accurately control the forward and backward driving of the piston 70.

  A trigger valve 74 that turns ON / OFF the discharge of the paint supplied from the third supply path 72 and the water, paint, etc. after cleaning the path in the paint gun 12 are directed to the waste liquid storage tank 58. A valve 80 to which a return path 66 for returning is connected is provided. Further, the coating gun 12 is internally provided with a high voltage generator 88 capable of generating a high voltage used during electrostatic coating.

  Next, the basic operation of the electrostatic coating apparatus 10 configured as described above will be described.

  When filling the cylinder 18 with paint, first, the valves 49 and 50 constituting the first switching valve 36 are opened, the valves 48 and 51 are closed, and the valves 62 constituting the second switching valve 38 are closed. 63 is opened, and the valve 61 is closed. In this state, the cylinder 18 is filled with the paint from the desired paint valve 20 of the color change valve 14. That is, as shown by a solid line in FIG. 2A, the paint from the paint valve 20 is sent from the first supply path 28 to the path 54 via the valve 50, and flows through the tube 34 from the valve 49 (see arrow A1). It is sent from the valve 62 to the second supply path 40 through the path 64 and the valve 63. In the cylinder 18, the piston 70 is moved backward by the motor 68 in accordance with the filling of the paint, and the paint is filled. 2A to 2C, the path through which the paint and the cleaning liquid (cleaning waste liquid) circulate is indicated by a solid line, and the remaining path is indicated by a broken line.

  After the filling of the cylinder 18 with the paint is completed, insulation by the insulation mechanism 16 is ensured. That is, the valves 49 and 51 constituting the first switching valve 36 are opened, the valve 50 is closed, and the valve 48 is switched to a state where the tube 32 and the discharge path 60 are communicated (in the direction of arrow X2 in FIG. 1). Further, the valve 62 constituting the second switching valve 38 is opened, the valve 63 is closed, and the valve 61 is switched to a state in which the tube 32 and the path 64 are communicated (in the direction of arrow Y1 in FIG. 1).

In this state, the cleaning liquid valve 42 constituting the cleaning valve 46 is opened, so that water from the cleaning liquid valve 42 passes through the cleaning path 56 to the path 54 and the valve 49 as shown by a solid line in FIG. 2B. And flows to the tube 34 (see arrow A1). The water that has flowed through the tube 34 flows from the valve 61 to the tube 32 via the valve 6 2 and the path 64 (see arrow A3), and is sent from the valve 48 to the discharge path 60 and then to the waste liquid storage tank 58. And discharged. Thereby, the paint remaining in the tubes 32 and 34 is washed away with water.

  Next, the cleaning liquid valve 42 is closed and the drying valve 44 is opened, whereby air is supplied along the same path as in the case of water, and the inside of the tubes 32 and 34 is dried. Thereby, the insulation between the 1st switching valve 36 and the 2nd switching valve 38 is ensured.

  In order to discharge the paint from the coating gun 12, the trigger valve 74 is opened, and the piston 70 is advanced by a motor 68 at a predetermined speed (constant speed), so that the paint filled in the cylinder 18 is discharged at a predetermined flow rate (constant). The flow rate) is extruded to the third supply path 72, and the paint is discharged through the trigger valve 74.

  In this case, a high voltage is applied to the painting gun 12 by the high voltage generator 88, and a high voltage is applied to the painting gun 12, the cylinder 18, the second switching valve 38, and each path in the middle thereof. However, since the insulation between the first switching valve 36 and the second switching valve 38 is reliably ensured by the tubes 32 and 34 constituting the insulating mechanism 16, the paint is made of a conductive paint such as a water-based paint. Even if there is, voltage leakage to the color change valve 14 and the waste liquid storage tank 58 does not occur, and satisfactory electrostatic coating is possible.

  In addition to filling the cylinder 18 with the paint using only the tube 34 as described above (single filling), the electrostatic coating apparatus 10 uses both the tubes 32 and 34 (see FIG. Double filling) is also possible.

  In double filling, first, the valves 49 and 50 constituting the first switching valve 36 are opened, the valve 51 is closed, and the valve 48 is in communication with the path 54 and the tube 32 (in the direction of arrow X1 in FIG. 1). ). Further, the valves 62 and 63 constituting the second switching valve 38 are closed, and the valve 61 is switched to a state where the tube 32 and the path 64 are communicated (in the direction of arrow Y1 in FIG. 1). In this state, the cylinder 18 is filled with the paint from the desired paint valve 20 of the color change valve 14. That is, as shown by a solid line in FIG. 2C, the paint from the paint valve 20 is sent from the first supply path 28 through the valve 50 to the path 54 and simultaneously flows to the valves 48 and 49. The paint from the valves 48 and 49 flows through the tubes 32 and 34 simultaneously (see arrows A1 and A2), and is sent from the valves 61 and 62 to the second supply path 40 through the path 64 and the valve 63.

  As described above, in the double filling, the paint supply amount to the cylinder 18 can be effectively suppressed from being restricted by the insulating mechanism 16 by simultaneously supplying the paints in the tubes 32 and 34 in parallel. That is, the filling speed of the paint into the cylinder 18 is improved, and the efficiency in the entire painting process can be improved. This double filling is particularly effective in the case of a paint having a high viscosity and requiring a long time for circulation in the tube. In addition, what is necessary is just to perform the ensuring of the insulation by the insulation mechanism 16 after that, and the discharge of the coating material from the coating gun 12 similarly to the case of the above single filling.

  After the coating with the predetermined paint is completed as described above, when each path is cleaned when the cylinder 18 is filled with another color paint, for example, the first switching valve 36, the second switching valve 38, etc. Is appropriately switched and a path substantially similar to that in the single filling is configured. Next, the cleaning liquid (water) is supplied from the cleaning liquid valve 22, and the path to the cylinder 18 through the tube 34 is cleaned. At this time, the valve 61 is switched to a state in which the return path 66 and the tube 32 are in communication (in the direction of arrow Y2 in FIG. 1), and the valve 48 is in a state in which the tube 32 and the discharge path 60 are in communication (in the direction of arrow X2 in FIG. 1). Switch over. Initially, the discharge path of the coating gun 12 is cleaned from the third supply path 72 through the trigger valve 74, and then the trigger valve 74 is closed and the valve 80 is opened to supply the cleaning waste liquid from the return path 66. 61, discharged from the discharge path 60 to the waste liquid storage tank 58 via the tube 32. Next, the air from the drying valves 26 and 44 is circulated in the same manner as in the cleaning with the cleaning liquid to dry the inside of each path.

  As described above, according to the electrostatic coating apparatus 10 according to the present embodiment, the cylinder 18 (the coating gun 12) and the first switching valve 36, the second switching valve 38, and the insulating mechanism 16 having the tubes 32 and 34. The color change valve 14 can be reliably insulated.

  In addition, the discharge path 60 connected to the waste liquid storage tank 58 on the paint discharge side is the first switching valve on the color change valve 14 side (upstream side in the paint filling direction) of the tubes 32 and 34 constituting the insulating mechanism 16. It is connected only to 36. In other words, the path communicating with the discharge side of the cleaning waste liquid containing the paint is connected only to the first switching valve 36 side rather than the tubes 32 and 34. The tubes 32 and 34 do not have a discharge path on the cylinder 18 side (downstream side in the paint filling direction), and the return path 66 from the coating gun 12 also goes to the discharge path 60 via the tubes 32 and 34. Communicate. Therefore, the voltage does not leak to the discharge path 60 in a state where the insulation of the insulating mechanism 16 is secured after the cylinder 18 is filled with the paint.

  That is, even if dirt due to cleaning waste liquid or the like is attached to the discharge path 60, voltage leakage from the discharge path 60 can be reliably prevented, and the downstream side (cylinder 18 side) from the insulating mechanism 16 can be prevented. ) Has no path connected to the outside, and the reliability of the electrostatic coating apparatus 10 can be improved. In other words, the discharge path 60 can be used as long as the cleaning waste liquid or the like can be discharged to the waste liquid storage tank 58, and does not require special maintenance. Therefore, for example, it extends from the feet of the robot on which the electrostatic coating apparatus 10 is mounted to the external waste liquid storage tank 58, thereby reducing the replacement cost of the discharge path 60 that is configured to be considerably longer than the tube 32 or the like. Can do. In this regard, even when the tubes 32 and 34 are deteriorated due to use over time and the insulating properties thereof are lowered, the tubes 32 and 34 have the same diameter and the same scale, and compared with the discharge path 60. Since they are quite short, they can be easily and inexpensively replaced by common spare parts.

  Furthermore, in the electrostatic coating apparatus 10, by performing the above-described double filling in which the paint is supplied to the cylinder 18 simultaneously in parallel by the tubes 32 and 34, the paint filling speed can be greatly improved, and the entire painting process is performed. It is possible to improve the efficiency.

  In the above embodiment, the number of tubes constituting the insulation mechanism may be two or more. For example, the number of tubes that supply the paint from the color change valve 14 to the cylinder 18 is two, and the discharge path 60 is washed. You may make it provide the tube which discharges | emits waste liquid etc. separately. Moreover, these tubes 32 and 34 do not necessarily have the same diameter and the same scale, and may have different diameters or different scales. Further, the cylinder 18 may be provided in the coating gun 12.

  It goes without saying that the paint filling procedure (filling route) and the cleaning liquid circulation procedure (circulation route) into the cylinder 18 can be appropriately changed in addition to those exemplified above.

  As described above, the present invention has been described with the embodiment. However, the present invention is not limited to this, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

It is a block diagram of the electrostatic coating apparatus which concerns on one Embodiment of this invention. FIG. 2A is a partially omitted structural diagram for explaining a distribution route of the paint at the time of single filling in the electrostatic coating apparatus shown in FIG. 1, and FIG. 2B is an insulation in the electrostatic coating apparatus shown in FIG. FIG. 2C is a partially omitted structural diagram for explaining a flow path of the cleaning liquid and cleaning waste liquid when ensuring the insulation of the mechanism, and FIG. 2C is a flow path of the paint when double filling is performed in the electrostatic coating apparatus shown in FIG. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrostatic coating apparatus 12 ... Coating gun 14 ... Color change valve 16 ... Insulation mechanism 18 ... Cylinder 32, 34 ... Tube 36 ... 1st switching valve 38 ... 2nd switching valve 46 ... Washing valve 56 ... Washing path 58 ... Waste liquid Reservoir 60 ... discharge path

Claims (2)

An electrostatic coating apparatus having a cylinder capable of filling and extruding paint, and a paint supply valve for supplying conductive paint to the cylinder, and having an insulating mechanism between the cylinder and the paint supply valve,
The insulating mechanism includes a plurality of tubes made of an insulating material,
A first switching valve connected to an end of each tube on the paint supply valve side;
A second switching valve connected to an end of each tube on the cylinder side;
With
The first switching valve is connected to a discharge path communicating with the waste liquid discharge side ,
The insulating mechanism includes a cleaning valve, and a cleaning path communicating with the cleaning valve is connected to the first switching valve,
When cleaning the inside of the tube to ensure insulation in the insulating mechanism, the cleaning liquid from the cleaning valve flows from the first switching valve to the second switching valve through one tube. , from the second switching valve via the other tube returns to the first switching valve, an electrostatic coating apparatus according to claim Rukoto is discharged to the discharge path from the first switching valve. An electrostatic coating apparatus having a cylinder capable of filling and extruding paint, and a paint supply valve for supplying conductive paint to the cylinder, and having an insulating mechanism between the cylinder and the paint supply valve,
The insulating mechanism includes a plurality of tubes made of an insulating material,
A first switching valve connected to an end of each tube on the paint supply valve side;
A second switching valve connected to an end of each tube on the cylinder side;
With
Wherein the first switching valve, the discharge passage communicating with the discharge side of the liquid waste, Rutotomoni only connected to the first switching valve side of the tube, the waste liquid, waste liquid and the time of washing at least the cylinder An electrostatic coating apparatus comprising a waste liquid when the tube is washed .

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