JP2509542Y2 - Electrostatic coating equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal application type electrostatic coating device for performing electrostatic coating by directly applying a high voltage to a conductive coating.

[0002]

2. Description of the Related Art Conventionally, as a technique for applying a high voltage directly to a conductive coating to electrostatically coat an object to be coated, one disclosed in US Pat. No. 4,771,729 is known. ing.

In this conventional technique, the conductive paint is once introduced into the intermediate storage tank from the paint supply source through the supply path, and then this supply path is washed and dried to bring the electrically insulated state (voltage block) into consideration. With the construction configured to prevent the current from leaking to the paint supply side, the paint to which a high voltage is directly applied is supplied from the intermediate storage tank to the coating gun to electrostatically coat the object to be coated. Work is being done.

[0004]

However, in this type of internal application type electrostatic coating apparatus, a considerable amount of electric charge remains in the coating material and the apparatus itself, especially in the intermediate storage tank. It has been pointed out that when the conductor is abnormally close to the conductor, sparks are generated due to the residual charges even if the application of the high voltage is stopped, which causes a coating failure or the like.

The present invention solves this type of problem and allows the residual charge in the device to be discharged quickly and reliably, thereby preventing the occurrence of sparks in the event of abnormal conditions and improving efficiency. An object of the present invention is to provide an electrostatic coating device capable of performing a typical electrostatic coating operation.

[0006]

In order to achieve the above-mentioned object, the present invention provides a grounded paint supply source and a conductive paint from the paint supply source to a storage tank, and at least a part thereof. A supply path provided with an electrically insulating path,
Means for electrically insulating the paint supply source and the storage tank by washing and drying the insulation path, and provided at the end of the insulation path on the storage tank side, at least the insulation path and the storage tank can be opened and closed. And a grounded high resistance body connected to the switching valve.

[0007]

In the electrostatic coating apparatus according to the present invention described above, after the conductive paint is once stored in the storage tank from the paint supply source via the supply path, the insulating path provided in a part of this supply path is In a state where the paint supply source and the storage tank are electrically insulated after being washed and dried, a high voltage is directly applied to the paint drawn from the storage tank to perform electrostatic coating work. Then, the electric charge remaining in the storage tank is quickly and surely discharged to the ground side through the high resistance body connected to the switching valve.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electrostatic coating apparatus according to the present invention.

In FIG. 1, reference numeral 10 indicates an electrostatic coating apparatus according to this embodiment. This electrostatic coating device 10
The grounded color change valve mechanism 12, an intermediate storage section 14 that temporarily stores the conductive water-based paint supplied from the color change valve mechanism 12 through the supply path 13, and the intermediate storage section 1
Four-way switching valve 18 connected to the No. 4 via the supply path 16
And a coating gun 22 connected to the outlet side of the four-way switching valve 18 via a delivery path 20.

The color change valve mechanism 12 includes air (A) and water (W).
And a cleaning valve 24 for controlling the supply of cleaning liquid (S) and the like,
It is provided with a plurality of paint valves 26a to 26c capable of supplying water-based paints of different colors. This color change valve mechanism 1
The intermediate storage section 14 connected to the outlet side of 2 is separated from the storage tank 28 in which the water-based paint is temporarily stored by ensuring a predetermined distance from each other and arranged along the storage tank 28. 3-way switching valve (switching valve) 30a, 3 made of conductive material
0b and a block valve mechanism 34 provided with an insulating path 32 having a length capable of insulating a predetermined high voltage and forming a part of the supply path 13 (see FIG. 2).

A color change valve mechanism 12 and a grounded first cleaning valve mechanism 36 are connected to the inlet side of the three-way switching valve 30a, and the first cleaning valve mechanism 36 has at least the insulating path 32. A cleaning valve 38, which is a means for cleaning with water (W) and a cleaning liquid (S), and an air supply valve 40, which is a means for drying the insulating path 32, are provided. Three-way switching valve 30b
A waste liquid tank 44 is connected to the outlet side of the three-way switching valve 30b and the three-way switching valve 30a via a discharge path 42.
A high resistance element (for example, about 5 GΩ) R is arranged at the position. The three-way switching valves 30a, 30b are connected via the high resistance body R.
Is electrically connected and the three-way switching valve 30a
Is grounded via the color change valve mechanism 12.

The storage tank 28 is provided with a first cylinder chamber 48 for injecting paint, cleaning liquid, etc., which is divided via a piston 46.
And a second cylinder chamber 50 for air supply.
In the cylinder chamber 50, an air supply source 52 is provided with a flow rate adjusting valve 54,
It communicates via the on-off valve 56. This air supply source 52 is
It is connected to a paint flow rate controller 60 for adjusting the air pressure via the booster 58, and the flow rate controller 60 controls the discharge amount of the paint.

A four-way switching valve 18 is connected to the first cylinder chamber 48 of the storage tank 28 via a supply path 16, and the four-way switching valve 18 is connected to a flow rate controller 60 and a coating gun 22 via a delivery path 20. Connected to. A second cleaning valve mechanism 66 including a cleaning valve 62 and an air supply valve 64 is connected to the inlet side of the four-way switching valve 18, and the second cleaning valve mechanism 66 includes
It is connectable to the waste passage 70 via the delivery passage 20 and the discharge passage 68.

The coating gun 22 includes a dump valve 72, a trigger valve 74 and a high voltage applying means 75. The dump valve 72 is connected to a waste liquid tank 70 via a discharge path 76, A washing valve 78 is provided on the way of the discharge path 76.
And a third cleaning valve mechanism 82 provided with an air supply valve 80 are connected.

Next, the operation of the electrostatic coating device 10 thus constructed will be described.

First, when the paint of a predetermined color derived from the paint valve 26a of the color changing valve mechanism 12 is supplied to the block valve mechanism 34 of the intermediate storage section 14, this paint is applied to the three-way switching valve 3
0a, the insulating path 32, and the three-way switching valve 30b to fill the first cylinder chamber 48 of the storage tank 28. This first
The paint with which the cylinder chamber 48 is filled passes through the supply path 16, the four-way switching valve 18 and the delivery path 20, and the coating gun 2
Fill up to 2. During this filling, the trigger valve 74 is closed, while the dump valve 72 is opened, and after the filling, the dump valve 72 is closed.

Then, the switching operation of the three-way switching valves 30a and 30b constituting the block valve mechanism 34 is performed, the first cleaning valve mechanism 36 communicates with one end side of the insulating path 32, and the other end of the insulating path 32. The side communicates with the waste liquid tank 44 via the discharge path 42. In this state, the first cleaning valve mechanism 3
The cleaning liquid under the driving action of the cleaning valve 38 constituting 6 cleans the three-way switching valve 30 a, the insulating path 32 and the three-way switching valve 30 b, and is discharged from the discharge path 42 to the waste liquid tank 44.

After the cleaning is completed, dry air is supplied from the air supply valve 40 constituting the first cleaning valve mechanism 36, and at least the inside of the insulating path 32 is dried by this dry air, so that the color change valve mechanism 12 and the storage tank 28 are connected. Are electrically isolated. Next, from the air supply source 52 to the flow rate adjustment valve 54
Driving air is supplied to the second cylinder chamber 50 of the storage tank 28 via the open / close valve 56, the piston 46 is displaced to the first cylinder chamber 48 side, and the paint is applied to the high voltage applying means 75.
Under the action of high voltage is directly applied to the trigger valve 74
Is supplied to the work (not shown) under the opening action.

Next, the driving of the high voltage applying means 75 is stopped, and the work of supplying the coating material to the storage tank 28 is performed as described above. In many cases, a considerable amount of electric charge remains.
Here, in this embodiment, a three-way switching valve 30b made of a conductive material is provided at the end of the insulating path 32 on the storage tank 28 side, and the high resistance body R is arranged in the three-way switching valve 30b and the three-way switching valve 30a. Has been done. Therefore, the electric charge remaining in the storage tank 28 is rapidly and surely discharged to the ground side through the three-way switching valve 30b, the high resistance element R and the three-way switching valve 30a, which is considerably shorter than that of the conventional electrostatic coating device. In time, the work of discharging the residual charge is performed. As a result, even if the coating gun 22 abnormally approaches a conductor such as a work immediately after the application of high voltage to the coating material is stopped, it is possible to effectively prevent the occurrence of sparks and the like, and cause coating failure. It is possible to obtain an effect that an efficient and highly accurate electrostatic coating work can be performed without any problem. Moreover, since the high resistance R is selected to be, for example, about 5 GΩ, it is possible to prevent the high resistance R from leaking more than necessary when a high voltage is applied to the paint for electrostatic coating. No paint defects will occur.

Further, as shown in FIG. 2, the high resistance element R is
Compactly arranged in parallel with the insulation path 32,
It is possible to prevent the entire intermediate storage unit 14 from increasing in size.

In this embodiment, the high resistance element R is arranged between the three-way switching valves 30a and 30b, but at least the storage tank 28 side of the insulating path 32, that is, the three-way switching valve 30b is made of a conductive material. The three-way switching valve 30b may be connected to the grounded high resistance element R. When a plurality of two-way switching valves are provided, a two-way switching valve disposed close to the storage tank may be provided with a grounded high resistance body.

[0022]

According to the electrostatic coating device of the present invention, the following effects can be obtained.

Since the electric charge remaining in the storage tank is quickly and surely discharged to the ground side through the high resistance element connected to the switching valve arranged in the vicinity of the storage tank, the work such as a coating gun can be discharged. Even if the conductive member is abnormally approached, the residual charge in the storage tank does not cause inconvenience such as spark generation, and it is possible to avoid defective coating and perform highly accurate and efficient coating work. .

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an electrostatic coating apparatus according to this embodiment.

FIG. 2 is an enlarged explanatory view of a main part of the electrostatic coating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Electrostatic coating device 12 ... Color change valve mechanism 13 ... Supply path 14 ... Intermediate storage part 16 ... Supply path 18 ... Four-way switching valve 20 ... Delivery path 22 ... Painting gun 28 ... Storage tanks 30a, 30b ... Three-way switching valve 32 ... Insulation path 34 ... Block valve mechanism 36, 66, 82 ... Washing valve mechanism R ... High resistance body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ichiro Ishibashi 1-10-1 Shin-Sayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. (56) Reference JP-A-2-2885 (JP, A)

Claims (2)

(57) [Scope of utility model registration request] 1. A grounded paint supply source, a supply path in which a conductive paint is supplied from the paint supply source to a storage tank, and at least a part of which is provided with an electrical insulation path, and the insulation path is cleaned. A means for electrically insulating the paint supply source and the storage tank by drying, and a conductive material switch provided at an end portion of the insulation path on the storage tank side and capable of opening and closing at least the insulation path and the storage tank An electrostatic coating device comprising a valve and a grounded high resistance body connected to the switching valve. 2. The device according to claim 1, wherein the switching valve provided at the end of the insulating path on the reservoir side is made of a conductive material for selectively communicating the insulating path with the supply path and the discharge path of paint or the like. A three-way switching valve, which is provided with a conductive material three-way switching valve for selectively communicating the insulating path with the paint supply source and the cleaning valve, is provided at the end of the insulating path on the paint supply source side. The electrostatic coating device is characterized in that the grounding part is a three-way switching valve provided at the end of the insulating path on the paint supply source side.