JP3658085B2 - Electrostatic coating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic coating apparatus that performs electrostatic coating by supplying conductive paint to a coating gun via a paint supply path.
[0002]
[Prior art]
Generally, an electrostatic coating apparatus using a conductive paint is supplied with a conductive paint from a paint supply source through a paint supply path to a paint gun, and the conductive paint is in a state where a high voltage is applied. By being derived from the coating gun, the workpiece is electrostatically coated.
[0003]
In this type of electrostatic coating apparatus, it is necessary to prevent high-voltage leakage, and various measures against insulation have been conventionally taken. For example, as disclosed in Japanese Patent Laid-Open No. 4-63156, a reciprocating pump that pushes conductive paint introduced from an input port through a paint supply pipe through an output port at a predetermined flow rate is supplied to the reciprocating pump. The paint pipe that supplies the conductive paint to the electrostatic coating machine and the drain pipe that discharges the conductive paint remaining in the reciprocating pump through the drain pipe along with the cleaning air and cleaning liquid supplied from the paint supply pipe can be switched. There is known an electrostatic coating apparatus in which the paint supply pipe and the drain pipe are connected to the input port side connection port and the drain pipe side connection port of the reciprocating pump in a detachable manner.
[0004]
[Problems to be solved by the invention]
However, in the above-described prior art, the drain pipe and the drain pipe which are dump paths are separable for insulation, so that the drain pipe is connected to the drain pipe side connection port and the drain pipe in particular. There is a risk that the paint. This is because the dump path is separable and therefore does not need to be completely cleaned, the cleaning time is set short, and the paint tends to remain. For this reason, the sealing property in a connection part cannot be ensured, and the drainage liquid containing a paint dripped from this connection part at the time of isolation | separation, and the problem that the leak of a high voltage generate | occur | produces has been pointed out.
[0005]
On the other hand, on the paint supply piping side, the paint supply piping is freely detachable from the input port side connection port of the reciprocating pump. Therefore, there are also problems such as a decrease in sealing performance due to the adhesion of the paint and a high voltage leak due to the dripping of the paint even at the connection portion between the paint supply pipe and the input port side connection port.
[0006]
Moreover, after the paint is introduced into the reciprocating pump from the paint supply pipe, the paint supply pipe is separated from the input port side connection port. As a result, the paint supply pipe and the input port side connection port are engaged and disengaged every time the paint is supplied, and there is a problem that the paint adheres to the connecting portion.
[0007]
The present invention solves this type of problem, and with a simple configuration, it is possible to reliably perform the cleaning operation of the connecting portion, and to effectively prevent the paint or the like from remaining on the connecting portion. An object is to provide a possible electrostatic coating apparatus.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention is directed to performing an electrostatic coating operation by supplying a conductive paint to a coating gun via a paint supply path and applying a high voltage to the conductive paint. Is done. At that time, the first on-off valve is closed while the first and second connection portions constituting the connection mechanism are connected, and the second and third on-off valves are opened, thereby allowing the cleaning medium supply source to pass through. Thus, the operation of cleaning the connecting portion of the first and second connecting portions is performed.
[0009]
As a result, the connecting portion of the first and second connecting portions that are detachable from each other is always and reliably cleaned via the cleaning medium supply source, and it is effective that the paint remains in the connecting portion. Can be prevented.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration explanatory diagram of an electrostatic coating apparatus 10 according to an embodiment of the present invention.
[0011]
The electrostatic coating apparatus 10 includes a grounded color change valve mechanism 12 that selectively supplies a plurality of different paints, a paint gun 14 that injects the paint onto a workpiece (not shown), the color change valve mechanism 12, and the An intermediate storage tank 16 interposed between the coating gun 14 and supply paths 18a and 18b provided between the intermediate storage tank 16 and the color change valve mechanism 12 can be freely connected and separated. A connection mechanism 22 that electrically connects and separates the dump path 20 branched from 18b into the first dump path section 20a to which a high voltage is applied and the other second dump path section 20b is provided.
[0012]
The color change valve mechanism 12 includes a first cleaning valve 24 that controls supply of air (A), water (W), cleaning liquid (S), and the like, and a plurality of paint valves 26a to 26n that can supply different paints. And.
[0013]
The connection mechanism 22 is connected to the intermediate storage tank 16 via an application-side supply path 18b, and is connected to the color change valve mechanism 12 via a non-application-side supply path 18a. And a movable block (second connecting portion) 30 to be provided. The movable block 30 is connected to a rod 34 that extends from an air cylinder 32 that is a driving means, and is movable forward and backward in the direction of arrow A.
[0014]
The movable block 30 is provided with first and second male valve elements 36 and 38. As shown in FIG. 2, a first through hole 40 communicating with the supply path 18 a is formed in the first male valve body portion 36, and an X1 on-off valve 42 is disposed in the first through hole 40. . A first cleaning path 44 is formed in the second male valve body 38, and the first cleaning path 44 is integrated with the second and third cleaning paths 46 and 48 branched from the first through hole 40. And communicated with the second dump path 20b. In the first to third cleaning paths 44, 46, 48, an X2 on-off valve (second on-off valve) 50, an X3 on-off valve (second on-off valve) 52, and an X4 on-off valve 54 are disposed, respectively.
[0015]
The fixed block 28 is provided with first and second female valve bodies 56 and 58, and as shown in FIG. 2, the first female valve body 56 communicates with the supply path 18b. A second through hole 60 is provided, and a Y1 on-off valve 62 is disposed in the second through hole 60. A first dump path portion 20a is provided in the second female valve body 58, and a Y2 on-off valve (first on-off valve) 64 is disposed in the first dump path portion 20a.
[0016]
A first branch path 68 connected to a second cleaning valve 66 serving as a cleaning medium supply source is provided on the downstream side of the Y2 on-off valve 64, and a first female valve body is provided along the first branch path 68. A second branch path 70 communicating with the portion 56 is branched. In the state where the first and second male valve body portions 36 and 38 and the first and second female valve body portions 56 and 58 are connected to the first and second branch paths 68 and 70, the second cleaning is performed. A Y3 on-off valve (third on-off valve) 72, a Y4 on-off valve (third on-off valve) 74, and a Y5 on-off valve 76 that allow the valve 66 to communicate with the second dump path portion 20b are provided.
[0017]
As shown in FIG. 1, the intermediate storage tank 16 includes a cylinder 80 in which a piston 82 is slidably reciprocated in the direction of arrow A. A paint filling cylinder chamber 84 is formed by the inner wall of the cylinder 80 and the tip of the piston 82. The cylinder wall 86 is formed with an injection hole portion 88 that is located at the inner peripheral edge of the cylinder wall 86 and communicates with the supply path 18 b, while a discharge hole portion 90 that is located at the center and communicates with the coating gun 14. Is provided.
[0018]
A ball screw 96 connected to a rotation shaft 94 of a servo motor 92 is connected to the piston 82. A cascade 98 is disposed adjacent to the cylinder 80, and this cascade 98 is connected to the low voltage supply source 100.
[0019]
As shown in FIG. 2, the coating gun 14 includes a supply path 106 that connects the paint discharge port 104 of the rotary atomizing head 102 and the supply path 18 b, and a dump path 20 that branches from the supply path 106. A trigger valve 108 is connected to the supply path 106, while a dump valve 110 is connected to the dump path 20. As shown in FIG. 1, a third cleaning valve 112 for cleaning the rotary atomizing head 102 is connected to the coating gun 14 via a cleaning path 114.
[0020]
The operation of the electrostatic coating apparatus 10 configured as described above will be described below.
[0021]
When performing color change coating using a paint of a different color, first, as shown in FIG. 2, electrostatic coating is performed by applying a high voltage to the previous color paint filled in the intermediate storage tank 16. While being performed (this operation will be described later), a color change cleaning operation is performed on the supply path 18a side on the non-application side.
[0022]
In other words, the area from the supply path 18a to the movable block 30 is cleaned through the first cleaning valve 24 constituting the color change valve mechanism 12, and the cleaning liquid used for this cleaning is discharged as X4 together with the residual paint. It is discharged from the second dump path 20b under the opening action of the on-off valve 54. Next, with the X4 opening / closing valve 54 closed, new paint is supplied to the supply path 18a from any one of the paint valves 26a to 26n (see FIG. 2).
[0023]
Therefore, when the movable block 30 moves in the direction of arrow A1 (see FIGS. 1 and 2) under the action of the air cylinder 32 constituting the connection mechanism 22, the first and second male valve elements 36 and 38 are fixed. The first and second female valve body portions 56 and 58 of the block 28 are joined. Then, as shown in FIG. 3, the X2 on-off valve 50, the Y1 on-off valve 62, the Y2 on-off valve 64, the Y4 on-off valve 74, the Y5 on-off valve 76, and the dump valve 110 are opened.
[0024]
Therefore, the water and air for cleaning led out from the second cleaning valve 66 are sequentially supplied to the supply path 18 b through the first branch path 68, the second separation path 70 and the second through hole 60. Water and air are sequentially introduced into the cylinder chamber 84 from the injection hole 88 of the cylinder 80 constituting the intermediate storage tank 16, and after the inside of the cylinder chamber 84 is cleaned, it is introduced into the coating gun 14 from the discharge hole 90. The Water and air are further sent from the supply path 106 in the coating gun 14 to the first dump path part 20a constituting the dump path 20, and the second male valve body part 38 and the second female valve body part 58 are connected to each other. It is discharged from the first cleaning path 44 to the second dump path section 20b through the connecting portion.
[0025]
As a result, the previous color paint remaining in the path from the fixed block 28 on the high voltage application side to the coating gun 14 is washed away. At that time, the trigger valve 108 is driven to open and close, so that the entire supply path 106 that reaches the paint discharge port 104 of the rotary atomizing head 102 is appropriately cleaned.
[0026]
Next, as shown in FIG. 4, the X1 on-off valve 42, the X2 on-off valve 50, the Y1 on-off valve 62, the Y2 on-off valve 64, and the dump valve 110 are opened. Therefore, the next color paint supplied to the supply passage 18a is supplied from the first through hole 40 to the supply passage 18b through the second through hole 60, and fills the front end side of the cylinder chamber 84 of the intermediate storage tank 16. Then, it is sent from the supply path 106 to the first dump path section 20a and the second dump path section 20b, and the air in the path is vented.
[0027]
Thereafter, the Y2 on-off valve 64 and the dump valve 110 are closed and the servo motor 92 is driven, and the piston 82 moves integrally with the ball screw 96 in the direction of the arrow A2 (in FIG. 4, from the position of the two-dot chain line to the solid line). See location). As a result, the cylinder chamber 84 is filled with the next color paint.
[0028]
After the intermediate color storage tank 16 is filled with the next color paint, the first and second male valve body portions 36 and 38 which are the connection portions of the fixed block 28 and the movable block 30 constituting the connection mechanism 22 and the first and second The connecting portion with the second female valve body portions 56 and 58 is washed. That is, as shown in FIG. 5, the X2 on-off valve 50, the X3 on-off valve 52, the Y3 on-off valve 72, the Y4 on-off valve 74, and the Y5 on-off valve 76 are opened, and the first branch path 68 and the first Water and air are sequentially supplied to the bifurcated path 70.
[0029]
The water and air supplied to the second branch path 70 wash the connecting portion between the first male valve body portion 36 and the first female valve body portion 56, and then the second cleaning path 46 to the second dump path. It is discharged to the part 20b. On the other hand, the water and air supplied to the first branch path 68 wash the connecting portion between the second male valve body portion 38 and the second female valve body portion 58, and then the second and second water from the first cleaning path 44. It is discharged to the dump path 20b.
[0030]
When the connection mechanism 22 is cleaned, all the open / close valves including the X2 open / close valve 50 opened at the time of cleaning shown in FIG. 5 are closed. Then, the movable block 30 moves in the direction of the arrow A2 under the driving action of the air cylinder 32, and the movable block 30 is separated from the fixed block 28 with an insulation distance (see FIGS. 1 and 6).
[0031]
Next, the servo motor 92 is driven and the trigger valve 108 is opened while the low voltage supply source 100 is driven and a high voltage is applied to the coating material filled in the cylinder chamber 84 (see FIG. 6). ). Thereby, the paint in the cylinder chamber 84 is applied to a workpiece (not shown) from the paint discharge port 104 of the rotary atomizing head 102 of the coating gun 14 in a state where a high voltage is applied, and electrostatic coating is performed.
[0032]
In this case, in the present embodiment, when the color change painting operation is performed, the first color paint passes through the intermediate storage tank 16 after the next color paint is filled into the intermediate storage tank 16 through the supply paths 18a and 18b. And the connection part of the 2nd male type valve body parts 36 and 38 and the 1st and 2nd female type valve body parts 56 and 58 is washed via the 2nd washing valve 66 (refer to Drawing 5).
[0033]
Therefore, as shown in FIG. 6, when the movable block 30 constituting the connection mechanism 22 is separated from the fixed block 28 for electrostatic coating with the next color paint, the first and second male valves are used. Residual paint does not drip from the connecting portion between the body portions 36, 38 and the first and second female valve body portions 56, 58, and high voltage leakage can be reliably prevented. Moreover, there is no inconvenience that the paint adheres to the connecting portion and the sealing performance of the connecting portion is lowered, and the desired sealing property can be effectively maintained.
[0034]
By the way, when performing the painting work using the same color paint, after the painting work shown in FIG. 6 is completed, as shown in FIG. 7, the movable block 30 is moved in the direction of the arrow A1 under the driving action of the air cylinder 32. The movable block 30 is moved and joined to the fixed block 28. Then, while the trigger valve 108 is closed, the piston 82 moves in the arrow A2 direction via the servo motor 92 with the X1 on-off valve 42 and the Y1 on-off valve 62 opened. Thereby, the intermediate color storage tank 16 is filled with the same color paint through the supply path 18a, the first and second through holes 40, 60, and the supply path 18b.
[0035]
After the intermediate color storage tank 16 is filled with the same color paint, as shown in FIG. 8, the X1 on-off valve 42 and the Y1 on-off valve 62 are closed, and the X3 on-off valve 52, Y4 on-off valve 74, and Y5 on-off valve 76 are closed. Is released. For this reason, water and air are sequentially supplied from the first branch path 68 to the second branch path 70 under the action of the second cleaning valve 66, and the first male valve body portion 36 and the first female valve through which the paint has passed. The connection part with the body part 56 is washed, and the drained liquid is discharged to the second dump path part 20 b through the second washing path 46.
[0036]
Further, after the X3 on-off valve 52, the Y4 on-off valve 74, and the Y5 on-off valve 76 are closed, the movable block 30 is separated from the fixed block 28 via the air cylinder 32. In this state, as shown in FIG. 6, electrostatic coating with the same color paint is performed under the opening action of the trigger valve 108.
[0037]
Here, in this embodiment, when an electrostatic coating operation is performed using the same color paint, the first male valve body portion that becomes the paint path after the paint is filled into the intermediate storage tank 16 from the supply path 18a. The connection part of 36 and the 1st female type | mold valve body part 56 is wash | cleaned. Accordingly, the paint does not remain at the connection part, and when the movable block 30 is separated from the fixed block 28, the paint does not sag from the connection part and a high-voltage leak does not occur. It does not cause deterioration of the sealing performance. Thereby, there is an effect that a high-quality painting operation is efficiently performed with a simple configuration.
[0038]
【The invention's effect】
As described above, in the electrostatic coating apparatus according to the present invention, the operation of cleaning the connection portion of the first and second connection portions via the cleaning medium supply source in a state where the first and second connection portions are connected. Therefore, the connecting portions of the first and second connecting portions that are detachable from each other can always be kept clean. As a result, it is possible to reliably prevent the paint from remaining on the connecting portion with a simple configuration, and to effectively ensure the sealing performance of the connecting portion, and to drain the liquid containing the paint from the connection mechanism. Therefore, the occurrence of high voltage leakage can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electrostatic coating apparatus according to an embodiment of the present invention.
FIG. 2 is a circuit explanatory diagram of the electrostatic coating apparatus.
FIG. 3 is an explanatory diagram of a circuit when cleaning a path on a high voltage application side.
FIG. 4 is an explanatory diagram of a circuit when air is extracted from a path in order to fill a paint of the next color.
FIG. 5 is an explanatory diagram of a circuit during cleaning of the connection mechanism.
FIG. 6 is an explanatory diagram of a circuit during electrostatic coating.
FIG. 7 is an explanatory diagram of a circuit when the same color paint is filled.
FIG. 8 is an explanatory diagram of a circuit during cleaning of the connection mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Electrostatic coating apparatus 12 ... Color change valve mechanism 14 ... Coating gun 16 ... Intermediate storage tank 18a, 18b ... Supply path 20 ... Dump path | route 20a, 20b ... Dump path | route part 22 ... Connection mechanism 24, 66 ... Cleaning valve 26a- 26n ... Paint valve 28 ... Fixed block 30 ... Movable block 36, 38 ... Male valve element 40, 60 ... Through hole 42, 50, 52, 54, 62, 64, 72, 74, 76 ... Open / close valve 56, 58 ... Female valve body 68, 70 ... Branch path 80 ... Cylinder 84 ... Cylinder chamber 106 ... Supply path 108 ... Trigger valve 110 ... Dump valve

Claims (1)

An electrostatic coating apparatus that performs electrostatic coating by supplying conductive paint to a coating gun via a paint supply path,
The dump path that branches off from the paint supply path and discharges the drainage liquid containing the conductive paint is electrically insulated and separated into the first dump path section to which a high voltage is applied and the other second dump path section. With a connection mechanism
The connection mechanism has a first on-off valve coupled to the first dump path section, and a first connection section provided with a branch path coupled to a cleaning medium supply source downstream of the first on-off valve. When,
A second connecting part having a second on-off valve coupled to the second dump path part;
With
In the state where the first and second connecting portions are connected to the branch path, the cleaning medium supply source can communicate with the second dump path portion from the connecting portion of the first and second connecting portions. An electrostatic coating apparatus, wherein three on-off valves are connected.

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