JPH04215865A - Electrostatic coating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic coating device that performs electrostatic coating by directly applying a high voltage to conductive paint.

0002

[Prior Art] Conventionally, electrostatic coating equipment that applies high voltage to conductive paint to electrostatically paint objects to be painted, such as automobile bodies, has a color changing valve mechanism that is a paint supply source, and an intermediate storage tank. An insulation mechanism is provided to electrically insulate the tank from the tank, and a technique disclosed in US Pat. No. 4,771,729 is known, for example.

As shown in FIG. 3, in this prior art, an insulating mechanism 6 is disposed between the color change valve mechanism 2 and the intermediate storage tank 4, and this insulating mechanism 6 is connected to the conductive material from the paint gun 8. The color changing valve mechanism 2 and the intermediate storage tank 4 are electrically insulated when the paint is supplied to the object to be painted. The insulating mechanism 6 includes an insulating tube 10.
Two-way switching valves 12a are provided at the paint inlet and paint outlet of 0, respectively.
, 12b are arranged. A two-way switching valve 1 for introducing and discharging cleaning liquid is provided at the upper end side and the lower end side of this insulating pipe body 10.
4a, 14b, and a two-way switching valve 16 for introducing and discharging air.
a and 16b are connected.

0004

However, in the above-mentioned prior art, the insulation mechanism 6 has six two-way switching valves 12a, 1
2b, 14a, 14b, 16a and 16b, and this two-way switching valve 14 is provided in the middle of the insulating pipe body 10.
A pipe body for arranging a, 14b, 16a and 16b is connected. Therefore, the two-way switching valves 12a, 12
In addition to providing insulation between the two-way switching valves 12b and 14b, 1
It is necessary to ensure insulation between the insulation mechanism 6b, and the number of switching valves (two-way switching valves) used is large.
Another problem is that the structure of the entire electrostatic coating apparatus incorporating this insulation mechanism 6 becomes considerably larger and more complicated. Also, between the two-way switching valves 12a and 14a and between the two-way switching valve 12
It is difficult to clean the area between b and 16b, and liquid pools are likely to occur, so there are problems in that it takes time to dry and the insulation state becomes unstable.

The present invention solves this type of problem, and provides an electrostatic coating device that can reduce the number of switching valves used, easily simplify the configuration, and has excellent cleanability. The purpose is to provide.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a color change valve mechanism for selectively supplying conductive paint, cleaning liquid and air, and a color changing valve mechanism for selectively supplying conductive paint, cleaning liquid and air. a cleaning valve mechanism, a first directional control valve whose inlet side is connected to respective supply paths extending from the color change valve mechanism and the cleaning valve mechanism; and an outlet side of the first directional control valve;
A block path made of an insulating material connected at one end, a second directional control valve whose inlet side is connected to the other end of the block path, and connected to the outlet side of the second directional control valve via a supply path. a waste liquid tank connected to the other outlet side of the second directional control valve via a discharge path; and a coating gun connected to the intermediate storage tank via a delivery path; The present invention is characterized by comprising means for applying a high voltage to the conductive paint between the second directional control valve and the coating gun.

[0007]

[Operation] In the electrostatic coating device according to the present invention, the desired conductive paint is temporarily filled into the intermediate storage tank from the color change valve mechanism through the first directional control valve, the block path and the second directional control valve. After this block path is cleaned through the cleaning valve mechanism and the color change valve mechanism and intermediate storage tank are electrically insulated, the conductive paint to which a high voltage is applied is discharged from the paint gun. It is supplied to the workpiece and painting work is performed. At this time, the color change valve mechanism and the cleaning valve mechanism are selectively connected to the block path under the switching action of the first directional control valve, and this block path is connected under the switching action of the second directional control valve. It is selectively connected to the intermediate storage tank and the waste liquid tank. For this reason, the number of switching valves can be reduced compared to the case where two-way switching valves are used, the cleaning performance is excellent, and the overall configuration of the electrostatic coating apparatus can be easily simplified.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the electrostatic coating apparatus according to the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 20 indicates an electrostatic coating apparatus according to this embodiment. This electrostatic coating device 20 includes a color change valve mechanism 22 and a cleaning valve mechanism 24 that selectively supplies air (A), water (W), cleaning liquid (S), etc.
and a first three-way switching valve (directional control valve) 30 whose inlet side is connected to the respective supply paths 26 and 28 extending from the color change valve mechanism 22 and the cleaning valve mechanism 24, and the first three-way switching valve 30. a block path 32 made of an insulating material whose one end is connected to the outlet side of the block path 32; a second three-way switching valve (directional control valve) 34 whose inlet side is connected to the other end of the block path 32; An intermediate storage tank 38 is connected to the outlet side of the switching valve 34 via a supply path 36; and a waste liquid tank 42 is connected to the other outlet side of the second three-way switching valve 34 via a discharge path 40. , a coating gun 46 connected to the intermediate storage tank 38 via a delivery path 44, and a high voltage applying means (for applying high voltage to the conductive paint between the second three-way switching valve 34 and the coating gun 46). (not shown).

[0010] This color change valve mechanism 22 has air (A), water (
Washing valve 48 that controls the supply of washing liquid (S), washing liquid (S), etc.
and multiple paint valves 5 capable of supplying different paints.
0a to 50e. A block valve mechanism 52 is constituted by the first three-way switching valve 30, the block path 32, and the second three-way switching valve 34, which are arranged between the color change valve mechanism 22 and the intermediate storage tank 38.

The intermediate storage tank 38 includes a first cylinder chamber 56 for injecting paint, cleaning liquid, etc., which is divided by a piston 54, and a second cylinder chamber 58 for supplying air. , the air supply source 60 is the flow rate adjustment valve 6
2.Communicate via the on-off valve 64. This air supply source 60
is connected via a booster 66 to a paint flow rate regulator 68 for adjusting air pressure, and this flow rate regulator 68 controls the amount of paint discharged. This flow rate regulator 6
8 is provided in the sending path 44.

The coating gun 46 includes a dump valve 70 and a trigger valve 72, and is connected to known high voltage application means (not shown).

Next, the operation of the electrostatic coating apparatus 20 constructed as described above will be explained.

First, when paint of a predetermined color drawn out from the paint valve 50a of the color change valve mechanism 22 is supplied to the block valve mechanism 52 through the supply path 26, as shown in FIG. , the first three-way switching valve 30, the block path 32, the second three-way switching valve 34, and the supply path 36, and are filled into the first cylinder chamber 56 of the intermediate storage tank 38. The paint filled in this first cylinder chamber 56 passes through the delivery path 44 and is filled up to the paint gun 46. At the time of this filling, the trigger valve 72 is closed, while the dump valve 70 is opened, and after filling This dump valve 70 is closed.

Therefore, the first and second three-way switching valves 30 and 34 constituting the block valve mechanism 52 are switched, and the supply path 28 extending from the cleaning valve mechanism 24 is communicated with one end of the block path 32. , the other end side of this block path 32 communicates with a waste liquid tank 42 via a discharge path 40 (see FIG. 2). In this state, cleaning liquid is supplied to the first three-way switching valve 30 under the driving action of the cleaning valve mechanism 24, and this cleaning liquid cleans the block path 32 and is discharged from the discharge path 40 to the waste liquid tank 42. Then, the block valve mechanism 52 is dried, and thereby the color change valve mechanism 22 and the intermediate storage tank 38 are electrically insulated.

Next, the flow rate adjustment valve 62 is connected to the air supply source 60.
Driving air is supplied to the second cylinder chamber 58 of the intermediate storage tank 38 via the on-off valve 64, and the piston 54 moves into the first cylinder chamber 58.
Displaced to the cylinder chamber 56 side, the paint is supplied to a workpiece (not shown) under the opening action of the trigger valve 72 while a high voltage is applied.

In this case, in this embodiment, the color change valve mechanism 22
and the intermediate storage tank 38.
2 includes a block path 32 and first and second three-way switching valves 30 and 34 disposed at both ends of the block path 32. Therefore, compared to a conventional insulation mechanism in which a large number of two-way switching valves (for example, six switching valves) are arranged, the number of switching valves can be reduced at once.

Moreover, unlike when using a conventional two-way switching valve, there is no need to branch the block path 32, and therefore there is no need to consider insulation in the branched pipe. Therefore, it is possible to reliably ensure an insulated state, and the structure of the block valve mechanism 52 can be easily simplified.

Furthermore, a color change valve mechanism 22 and a cleaning valve mechanism 24 are provided.
are directly connected to the first three-way switching valve 30 via the respective supply paths 26 and 28, and the second three-way switching valve 34 is connected to an intermediate storage tank 38 via the supply path 36 and the discharge path 40. , and a waste liquid tank 42 are directly connected. Therefore, there is an advantage that the entire configuration of the electrostatic coating device 20 is simplified at once.

[0020]

[Effects of the Invention] According to the electrostatic coating apparatus according to the present invention, the following effects can be obtained.

Under the switching action of the first directional control valve, the color change valve mechanism and the cleaning valve mechanism are selectively connected to the block path, and this block path is connected to the intermediate linkage under the switching action of the second directional control valve. Since it is selectively connected to the storage tank and waste liquid tank, the number of switching valves can be reduced compared to when using two-way switching valves, and it is also easy to clean, making the overall configuration of the electrostatic coating equipment easy. It becomes possible to simplify the

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an electrostatic coating apparatus according to the present invention.

FIG. 2 is an explanatory diagram of the operation of the electrostatic coating device.

FIG. 3 is a schematic explanatory diagram of an electrostatic coating device incorporating a conventional insulation mechanism.

[Explanation of symbols]

20...Painting device 22...Color change valve mechanism 24...Washing valve mechanism 26, 28... Supply route 30...Three-way switching valve 32...Block route 34...Three-way switching valve 36...Supply route 38...Intermediate storage tank 40...Emission route 44...Sending route 46...painting gun 52...Block valve mechanism

Claims (1)

[Claims] 1. A color change valve mechanism that selectively supplies conductive paint, a cleaning liquid, and air, a cleaning valve mechanism that selectively supplies the cleaning liquid and air, and a color change valve mechanism that extends from the color change valve mechanism and the cleaning valve mechanism. a first directional control valve whose inlet side is connected to each supply path; a block path made of an insulating material whose one end is connected to the outlet side of the first directional control valve; and the other end of the block path; a second directional control valve to which the inlet side is connected; an intermediate storage tank connected to the outlet side of the second directional control valve via a supply path; and a discharge port to the other outlet side of the second directional control valve. A high voltage is applied to the conductive paint between the waste liquid tank connected to the waste liquid tank via the route, the paint gun connected to the intermediate storage tank via the delivery route, the second directional control valve, and the paint gun. An electrostatic coating device characterized by comprising means for.