JP4365958B2 - Painting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating apparatus configured to be able to discharge paint to a workpiece by opening a paint path provided in the apparatus main body under the action of a paint valve.
[0002]
[Prior art]
In general, a coating apparatus that applies a high voltage to a paint (liquid paint) to apply electrostatic coating to an object to be coated such as an automobile body is employed. For example, the rotating mist is rotated under the rotating action of a rotating atomizing head. 2. Description of the Related Art A rotary atomizing coating apparatus that discharges paint from the tip edge of a chemical head by the action of centrifugal force is known.
[0003]
By the way, various coating apparatuses are provided with a paint valve (trigger valve) for opening and closing a paint path provided in the apparatus body, and by opening the paint path under the action of the paint valve, paint spraying means The paint is discharged from the workpiece to the workpiece. For example, as shown in FIG. 4, a coating machine disclosed in Japanese Patent Application Laid-Open No. 7-251103 constitutes a rotary atomizing electrostatic coating machine, and a rotary shaft 2 that can rotate via an air motor 1. A rotary atomizing head 3 is fixed to the tip. A high voltage is applied to the paint discharged from the rotary atomizing head 3 through the rotary atomizing head 3 from a high voltage applying means (not shown).
[0004]
The rotary shaft 2 is formed in a hollow shape, and a paint path 4 is formed inside the rotary shaft 2 and protrudes from the casing portion 6 constituting the paint valve 5 as a trigger valve with a stepped portion 7a. A valve body 7 is accommodated in the paint path 4 so as to freely advance and retract. The paint path 4 is provided with a valve seat portion 8 corresponding to the front end side of the valve body 7, while an end portion of the paint path 4 opposite to the valve seat portion 8 has an angle and has a paint passage 9. Are communicating.
[0005]
[Problems to be solved by the invention]
However, in the above prior art, since the stepped portion 7a is provided in the valve body 7 protruding from the paint valve 5, there is a problem that the cleaning performance of the stepped portion 7a is remarkably lowered when the paint path 4 is washed. It has been pointed out. In addition, the paint easily enters the gap between the casing portion 6 and the stepped portion 7a, and the cleaning operation of this gap becomes extremely difficult. As a result, for example, a problem has been pointed out that when color change coating is performed, a color mixture of the previous color paint and the new color paint occurs.
[0006]
The present invention solves this type of problem, and an object thereof is to provide a coating apparatus capable of performing a reliable and efficient cleaning operation with a simple configuration.
[0007]
[Means for Solving the Problems]
In the coating apparatus according to the present invention, a paint path for guiding the paint from the paint introduction part of the apparatus body to the outside, a valve stem part for opening and closing the paint path, and a paint path provided in the paint path In the coating apparatus, comprising: a valve seat on which a front end is seated; and a rod portion that is positioned on the rear end side of the valve rod portion and is slidably accommodated in a casing portion of the device main body. The rear end is provided with a tapered portion that is reduced in diameter toward the valve seat while being connected to the rod portion, and part of which enters the casing portion when the valve stem portion is opened, The coating material introducing portion can solve the above-described problem by being disposed so as to face a portion of the tapered portion that does not enter the casing portion when the valve stem portion is opened.
[0008]
According to this embodiment, since the tapered portion is provided (the step portion does not exist), the cleaning property of the tapered portion is effectively improved . Moreover, since a part of the taper part which reduces in diameter toward the valve seat side when the valve stem part is opened enters the casing part, a gap is formed between the casing part and the taper part. As a result, the cleaning liquid guided from the paint introduction part is reliably supplied to the gap. Therefore, the gap can be cleaned smoothly and reliably. In addition, since it is only necessary to provide the tapered portion, the configuration is simplified, and the manufacturing cost can be effectively reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an explanatory diagram of the schematic internal configuration of a rotary atomizing coating apparatus 10 according to an embodiment of the present invention.
[0010]
The coating apparatus 10 includes an apparatus main body 12. An air motor 14 is disposed in the apparatus main body 12, and a cylindrical rotating shaft 18 is integrally provided in an air turbine 16 constituting the air motor 14. The rotary atomizing head 20 is fixed to the tip of the rotary shaft 18. In the center of the apparatus main body 12, a pipe member 22 is disposed in the rotary shaft 18, and a paint path 24 and a cleaning path 26 are formed in the pipe member 22. The tips of the paint path 24 and the cleaning path 26 are open to the outside from the center side of the rotary atomizing head 20.
[0011]
The paint path 24 is configured to be able to discharge a predetermined paint to a workpiece (not shown) by being opened under the action of the paint valve 28. The paint path 24 comprises a discharge port 24a for discharging paint, a valve seat portion 30 provided inside the discharge port 24a, one end side communicating with the valve seat portion 30, and the other end side forming a paint valve 28. The housing part 34 communicates with the casing part 32 to be described later, and the paint introduction part 36 communicated with the housing part 34 at an angle with respect to the other end side of the housing part 34.
[0012]
The paint valve 28 includes a cylinder tube 40 that is fixed inside the apparatus main body 12, and a piston 42 that is movable back and forth in the axial direction (arrow A direction) by fluid pressure, for example, air pressure, is disposed in the cylinder tube 40. Is done. A rod portion 44 extends in the axial direction from the end portion of the piston 42, and a valve rod portion 46 is provided at the distal end portion of the rod portion 44. A seal ring 48 is attached to the peripheral surface of the rod portion 44, and the seal ring 48 is slidable along the inner peripheral surface 32 a of the casing portion 32.
[0013]
The valve stem portion 46 can freely close the paint passage 24 by being seated on the valve seat portion 30 of the paint passage 24. The accommodating portion 34 is provided with a paint introduction chamber 49 having an enlarged diameter at an end opposite to the valve seat portion 30, and the valve stem portion 46 is positioned at a position corresponding to the paint introduction chamber 49. A tapered portion 50 that is reduced in diameter toward the valve seat portion 30 side is formed. As shown in FIG. 2, at least a part of the taper portion 50 is arranged on the inner peripheral surface 32 a side of the casing portion 32 when the valve rod portion 46 is separated from the valve seat portion 30 to open the paint path 24. It is configured to be.
[0014]
As shown in FIG. 1, the apparatus main body 12 is provided with a shaping air path 52, a plurality of air passages 54 communicate with the leading end side of the shaping air path 52, and the leading end side of the air passage 54 has an opening 56. To the shaping air outlet 58. The shaping air outlet 58 is open toward the outer peripheral surface of the rotary atomizing head 20.
[0015]
The apparatus main body 12 is provided with a backup air path 60, an air passage 62 communicates with the front end side of the backup air path 60, and the front end of the air path 62 is opened to the rotary atomizing head 20 side. In the apparatus main body 12, a high voltage applying means (not shown) for charging the paint discharged from the rotary atomizing head 20 with static electricity is accommodated.
[0016]
The operation of the coating apparatus 10 configured as described above will be described below.
[0017]
Paint is supplied to the paint path 24 from a paint supply source (not shown), and the discharge of the paint is stopped when the valve rod portion 46 constituting the paint valve 28 is seated on the valve seat portion 30. Therefore, the rotary atomizing head 20 is rotated at high speed via the air turbine 16 under the action of the air motor 14, and the paint valve 28 is driven to move the valve stem 46 inward (in the direction of arrow A1). The tip of the valve stem portion 46 is separated from the valve seat portion 30. Therefore, the paint supplied to the paint path 24 is discharged from the discharge port 24a to the rotary atomizing head 20, and a high voltage is applied via a high voltage applying means (not shown).
[0018]
At that time, shaping air is supplied to the shaping air path 52, and this shaping air is jetted from the air path 54 to the rotary atomizing head 20 through the shaping air outlet 58, while being supplied to the backup air path 60. Air is led out from the air passage 62 to the back side of the rotary atomizing head 20. Thereby, the electrostatically charged paint is formed into a predetermined spray pattern in an atomized state, and a desired electrostatic coating operation is performed on a workpiece (not shown).
[0019]
Next, color change cleaning is performed in order to perform coating using different color paints. That is, after the paint introduction part 36 is communicated from a paint supply source (not shown) to the cleaning liquid supply source, the valve stem part 46 is separated from the valve seat part 30 under the action of the paint valve 28. For this reason, the cleaning liquid supplied to the coating material introduction part 36 is sent from the coating material introduction chamber 49 to the discharge port 24a through the container 34, and is discharged to the rotary atomizing head 20 through this discharge port 24a.
[0020]
In this case, in the present embodiment, a tapered portion 50 that is reduced in diameter toward the valve seat portion 30 side is formed in the valve stem portion 46. Accordingly, there is no step between the valve stem portion 46 and the rod portion 44, and the cleaning liquid introduced from the coating material introduction portion 36 into the coating material introduction chamber 49 can be removed from the taper portion 50 as shown in FIG. The taper portion 50 can be easily and reliably washed while smoothly flowing toward the paint path 24 along the inclination.
[0021]
Further, in a state where the valve stem portion 46 is separated from the valve seat portion 30, as shown in FIG. 3, at least a part of the taper portion 50 is disposed on the inner peripheral surface 32 a side of the casing portion 32 constituting the paint valve 28. ing. As a result, the paint that has entered the gap 64 between the valve stem portion 46 and the casing portion 32 can be reliably washed, and the effect of effectively improving the cleanability of the gap 64 can be obtained. Moreover, it is only necessary to form the taper portion 50 between the valve stem portion 46 and the rod portion 44, and the configuration of the entire coating apparatus 10 can be effectively simplified and the coating apparatus 10 can be manufactured economically. it can.
[0022]
【The invention's effect】
In the coating apparatus according to the present invention, the paint valve that opens and closes the paint path for discharging the paint to the workpiece has a valve stem portion that can be seated on a valve seat provided in the paint path. A taper valve that is reduced in diameter toward the valve seat side is formed on the rod portion. For this reason, a step part does not arise in a valve stem part, but the improvement of the washing nature of the valve stem part is aimed at. In addition, when opening the paint path by separating the valve stem portion from the valve seat portion, the taper portion is at least partially disposed in the casing portion constituting the paint valve, and the valve stem portion and the casing portion The paint that has entered the gap can be reliably washed, and the cleanability of the gap is effectively improved. As a result, color mixing does not occur when changing the color of the paint, and a high-quality painting operation is efficiently performed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a schematic internal configuration of a coating apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged explanatory view of a paint valve constituting the painting apparatus.
FIG. 3 is an explanatory diagram of a cleaning operation of the paint valve and the paint path.
FIG. 4 is a partial cross-sectional explanatory view of a coating machine according to a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Coating apparatus 12 ... Apparatus main body 14 ... Air motor 16 ... Air turbine 18 ... Rotating shaft 20 ... Rotary atomization head 24 ... Paint path 24a ... Discharge port 26 ... Cleaning path 28 ... Paint valve 30 ... Valve seat part 32 ... Casing part 32a ... Inner peripheral surface 34 ... Accommodating part 36 ... Paint introducing part 42 ... Piston 44 ... Rod part 46 ... Valve rod part 50 ... Taper part

Claims (1)

A paint path for guiding paint from the paint introduction part of the apparatus body to the outside;
A valve stem for opening and closing the paint path;
A valve seat that is provided in the paint path and on which a tip of the valve stem portion is seated;
In a coating apparatus comprising: a rod portion located on the rear end side of the valve stem portion and slidably accommodated in a casing portion of the device main body ,
At the rear end of the valve stem portion, there is a taper portion that is reduced in diameter toward the valve seat while being connected to the rod portion, and a part of which enters the casing portion when the valve stem portion is opened. Provided,
The coating apparatus, wherein the paint introduction portion is disposed so as to face a portion of the tapered portion that does not enter the casing portion when the valve stem portion is opened .

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