JP2704851B2 - Coatings for paint tubes in painting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for spraying a paint on an object to be coated.
The end of a paint tube that supplies paint is used for a painter or a painter that connects to a paint supply device.
To paint tube fittings.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show a conventional coating apparatus.
A rotary atomizing head type electrostatic coating apparatus will be described as an example.

In the drawing, reference numeral 1 denotes an electrostatic coating machine, 2 denotes a bell-shaped rotary atomizing head, and the rotary atomizing head 2 is fixed to a rotary shaft (both not shown) rotated by an air motor. Paint is supplied to the rotary atomizing head 2 through a paint passage 3 described later. The rotary atomizing head 2 discharges the paint while atomizing it radially outward by centrifugal force, and discharges the atomized paint by an external electrode (not shown) provided outside. Flying on a grounded object
You.

[0004] Reference numeral 3 denotes a paint passage formed in the electrostatic coating machine 1. The paint passage 3 has a base end connected to a paint supply pipe 12 described later and a tip end directed toward the rotary atomizing head 2. It is open. Further, in the middle of the paint passage 3 is provided paint valve 5 to be described later, opens the paint valve 5, by being closed, it sprayed paint contained inside.

[0005] Reference numeral 4 denotes a solvent passage. The solvent passage 4 has a base end connected to a solvent supply pipe 15 described later, and a tip end opening toward the rotary atomizing head 2. Further, in the middle of the solvent passage 4 is provided distal end washing valve 6 which will be described later, the tip-side cleaning valve 6, a solvent passage 4 opens, the closing to Rukoto, a cleaning fluid that will be supplied from the outside Atomizing head 2 rotating thinner
It is to be discharged toward.

Reference numeral 5 denotes a paint valve comprising a two-port, two-position pneumatic switching valve. The paint valve 5 is opened and closed by control air from the outside, and opens and closes the paint passage 3.

Reference numeral 6 denotes a distal-side cleaning valve comprising a 2-port, 2-position spring-return-type pneumatic switching valve. The distal-side cleaning valve 6 is opened and closed by external control air, thereby performing cleaning to be described later. It communicates and shuts off between the valve device 14 and the solvent passage 4.

Reference numeral 7 denotes a drainage passage formed in the electrostatic coating machine 1. The drainage passage 7 has a waste liquid tank having one end provided outside the electrostatic coating machine 1 through a drainage pipe 8. 9 and the other end is connected in the middle of the paint passage 3.

Reference numeral 10 denotes a drain valve provided in the middle of the drain passage 7. The drain valve 10 is a spring return type pneumatic switching valve having two ports and two positions, similarly to the front end cleaning valve 6. The drain valve 10 is opened and closed by external control air to communicate and shut off the connection between the drain passage 7 and the waste tank 9.

Reference numeral 11 denotes a color change valve device as a paint supply device provided outside the electrostatic coating machine 1.
1 is connected to a paint passage 3 of the electrostatic coating machine 1 through a paint supply pipe 12 as a paint tube.
A gear pump 13 is connected in the middle of 2. The color changing valve device 11 selectively discharges paints of two or more colors of A, B,... (Only two colors are shown), water, thinner, and air, and supplies them to the paint passage 3. .

Reference numeral 14 denotes the electrostatic coating machine 1 together with the color changing valve device 11.
1 shows a cleaning valve device provided outside the washing valve device.
Numeral 4 is connected to the front-end cleaning valve 6 via a solvent supply pipe 15, and connected to the solvent passage 4 via the front-end cleaning valve 6. The cleaning valve device 14 selectively discharges thinner and air for discharging toward the front side of the rotary atomizing head 2 and supplies them to the solvent passage 4.

[0012] 16, 16, ... is fitting for paint tube (hereinafter referred to as "joint 16") shows, each of said coupling 16, the color
Discharge port of valve replacement device 11 and end of paint supply pipe 12, gear
The supply port of the pump 13 and the end of the paint supply pipe 12, the gear port
Discharge port of pump 13 and end of paint supply pipe 12, electrostatic coating
The supply port of the paint passage 3 of the machine 1 and the end of the paint supply pipe 12
Each is connected.

The conventional rotary atomizing head type electrostatic coating apparatus has the above-described configuration. Next, the operation of the electrostatic spraying apparatus will be described with reference to FIG. I do.

[0014] First of all, after about cleaning factory after coating the end of the previous color,
The A-color supply process is performed, and the A-color paint is supplied to the paint supply pipe 12.
To the paint passage 3 and the rotary atomizing head 2.

[0015] In the as painters of the A color, shaft rotated by an air motor to rotate the rotary atomizing head 2. On the other hand, a high voltage is applied to the external electrodes. Next, when the paint valve 5 is switched from the switching position (a) to the switching position (b) and opened, the A color paint in the paint passage 3 is discharged toward the rotary atomizing head 2 and the rotary atomization is performed. It is atomized by the high-speed rotation of the head 2. The atomized A-color paint flies along the lines of electric force generated between the external electrode and the object to be coated while being charged while passing through the corona discharge region due to the high voltage of the external electrode. Thereby, the A-color paint is applied to the object to be coated.

Next, as the painter of the A color is completed, the paint for the next color, in the case of spraying an aqueous color B paint, paint supply pipe 12, remaining in the paint passage 3 or the like, adhered A color perform as cleaning factory to wash the paint.

[0017] That is, the higher the cleaning Engineering, switches the drain valve 10 from the switching position (a) to the switching position (B) is opened, after connecting the discharge passage 7 and the waste liquid tank 9, in FIG. 4 As shown, water, air, and thinner are alternately discharged from the color changing valve device 11 a plurality of times. As a result, the A-color paint remaining in the paint supply pipe 12, the paint passage 3, etc., is discharged from the drain passage 7 to the drain pipe 8.
And the like, and flows into the waste liquid tank 9 to be collected.

[0018] Then, when cleaning such as paint passage 3 is finished, switches the paint valve 5 to the switching position (B) opens, supplies thinner from the color changing valve apparatus 11 to the paint supply pipe 12. Coated Thus, from this thinner paint supply pipe 12
It flows out to the material passage 3 side , and cleans the tip side of the paint passage 3 and the rotary atomizing head 2 and the like.

[0019] However, in painters extent of the color A, A
The color paint adheres to the rotary atomizing head 2 due to the turbulent flow at the time of the ejection of the paint, and is dried and fixed to become the adhered paint. In this deposition paint extent aforementioned cleaning Engineering, since only injects thinner like toward the paint passage 3 to the rotary atomizing head 2,
Can not be washed. Therefore, in the as the cleaning engineering,
In addition to the above-described main cleaning of the paint passage 3 and the like, as shown in FIG. 5, auxiliary cleaning for spot cleaning is performed.

[0020] That is, the switch the distal end washing valve 6 from the switching position (a) to the change-over position (b) to open, to supply thinner from the wash valve device 14. As a result, the thinner is supplied from the solvent supply pipe 15 to the solvent passage 4, and is discharged from the solvent passage 4 to clean the adhered paint. When the cleaning of the adhered paint is completed, air is supplied from the cleaning valve device 14 into the solvent passage 4, and the thinner remaining in the solvent passage 4 is discharged into the coating booth by the air.

Finally, in the case of performing the B-color coating subsequent to the A-color coating, the color changing valve device 1 with the drain valve 10 opened.
1 supplies the B color paint into the paint passage 3 and the drain passage 7;
Next, the drain valve 10 is closed and the paint valve 5 is opened for a short time, whereby the B color paint is supplied to the rotary atomizing head 2 to prepare for the B color coating. Of the object to be coated is started.

[0022]

In the above-described prior art electrostatic coating apparatus, the color changing valve apparatus 11 is used.
The electrostatic coating machine 1 is connected to the electrostatic coating machine 1 via a paint supply pipe 12 having a gear pump 13 on the way, and performs color change according to the color of the object to be coated.

[0023] Therefore, in the extent washed Engineering, as well push the paint remaining in the paint supply pipe 12, the coating material adhering to the inner wall of the paint supply pipe 12 thinner, air (and, in the case of water-based paints Is flushed with water), but most of the passages are originally tubular. Therefore, the flow velocity in the tube faster central portion, since the vicinity of the inner wall is slowed, the extent washed Engineering has a high viscosity of the remaining paint, to produce the high viscous drag between the inner wall, paint supply pipe Only the air and the thinner penetrate through the center of 12. Thus, air in the higher wash Engineering in color changing valve device 11 must be repeated several times alternately supplying the thinner, it is impossible to cleanly wash the paint.

[0024] Consequently, as shown in FIG. 6, the coating layer without washed away the high viscosity paint every degree cleaning Engineering P1, P2,
P3 adheres to the inner wall surface of the paint supply pipe 12. Thus, the coating layer P3 outermost in degree-color paint Engineering is mixed into the next color paint, it is impossible to perform a clean painted to generate a color mixing paint.

[0025] The present invention has been made in view of the above-discussed problems with the prior art, the present invention is the flow of fluid flowing through the tube, in the coating apparatus which can in a spiral gaseous flow about the axis of the tube It is intended to provide a paint tube fitting.

[0026]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a paint tube in a coating apparatus employed by the present invention is provided.
The fitting for the tub is a paint supply device that supplies paint and cleaning fluid
A coating machine for spraying a coating material on an object to be coated;
Paint with a paint tube connecting between the
In the mounting device, the end of the paint tube is connected to the paint supply tube.
A joint body formed in a tubular shape to be connected to a supply device or a coating machine, and a paint on the supply side that is inserted and fitted in an axial direction in the joint body and that flows through the paint tube by twisting the plate body ;
And an element formed to give a spiral flow to the cleaning fluid .

[0027]

[Action] With the above structure, an elementary theft flows paint
To come, the inner wall surface of the flow of the paint tube of該塗Ryo tube
It can be a spiral flow that touches the vicinity ,
Faster flow in the vicinity of the inner wall of the tube, it can be Yukiwatara paint or cleaning fluid in the vicinity of the inner wall, at the time of washing
The inside of the tube is swirled by the cleaning fluid that has become a spiral flow.
Wash.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the prior art shown in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 21 denotes a paint tube joint (hereinafter referred to as a paint tube joint).
Indicates) called "joint 21",該継hand 21, like the joint 16 described in the prior art, a discharge port of the color changing valve apparatus 11
The end of the paint supply pipe 12 and the supply port of the gear pump 13
End of material supply pipe 12, discharge port of gear pump 13 and paint
End of supply pipe 12, supply of paint passage 3 of electrostatic coating machine 1
The mouth and the end of the paint supply pipe 12 are connected to each other.

The joint 21 has a stepped tubular joint body 22, a hexagonal nut 23 connecting the joint body 22 and the paint supply pipe 12, and an element 24 inserted into the joint body 22. It is composed of

[0031] Here, the joint body 22, the one side male threaded portion 22A formed on one side an outer peripheral surface, than the paint supply pipe 12 toward the other side is formed in a small diameter, the element 24 on the inner circumference The inserted cylindrical projection 22B and the cylindrical projection 2
An annular cylindrical portion 22D which is formed on the outer peripheral side of 2B and is formed in a coaxial cylindrical shape and has an external thread portion 22C formed on an outer peripheral surface thereof;
An annular concave portion 22E formed between the annular cylindrical portion 22D and the cylindrical projecting portion 22B, into which the end 12A of the paint supply pipe 12 is inserted, and a hexagonal portion 22F formed at an intermediate portion in the axial direction. Ru Ttei such from the.

The element 24 , as shown in FIGS. 2 and 3, is inserted into the cylindrical protruding portion 22B of the joint body 22 and then fixed by means of an adhesive or the like. It is formed by twisting by 180 °, and generates a spiral flow 25, 25 which divides the flow from one side into two and contacts the vicinity of the inner wall surface .

The paint tube joint 21 constructed as described above is formed at the discharge port 13A of the gear pump 13, so that the one-side external thread portion 22A is screwed to the thread portion 13B via the O-ring 26, and the paint supply pipe is provided. After inserting the end 12A of the twelve into the annular concave portion 22E, the hexagon nut 23 is screwed to the other male screw portion 22C so as to sandwich the annular convex portion 12B. Thus, in one side of the paint tube fitting 21 to prevent paint leaks at the O-ring 26, thereby preventing the paint from leaking by the annular protrusion 12B of the paint supply pipe 12 at its other side.

Each element 2 in each joint 21
The twist direction 4 is formed so that the spiral flow 25 in the paint supply pipe 12 is in the same direction.

The electrostatic coating apparatus used in this embodiment has the above-described configuration, and there is no particular difference in the basic operation of the electrostatic coating apparatus from that of the prior art.

However, the paint tube joint 21 according to the present embodiment is provided with the element 24 therein, and has a spiral shape.
Flow 25 can be generated. As a result, the paint
In Cheng Hao, by increasing the inner wall surface near than the central portion of the flow of paint tube of paint supply pipe 12, it is possible to Yukiwatara paint around the inner wall, the paint remaining in the vicinity of the inner wall The amount can be reduced. Furthermore, the degree cleaning Engineering is thinner supplied alternately, also the air flow can be spirally, it is possible to Yukiwatara cleaning fluid in the vicinity of the inner wall, before remaining in the vicinity of the inner wall of the tube color <br/> The paint can be reliably washed off by flushing.

Thus, in this embodiment, the paint tube joint 21 for generating the spiral flow 25 is connected to the paint supply pipe 12 for connection to the electrostatic coating machine 1 and the color changing valve device 11.
By using the tether portion, the amount of paint remaining in the paint supply pipe 12 after completion as painter to can be reliably reduced, and wash securely paint remaining on the inner wall surface of the pipe to the extent of cleaning Engineering Can be . As a result, compared with the prior art, the thinner the more cleaning engineering, it is possible to reduce the number of repetitions of the air alternate supply, thinner volume and washing time during washing can be effectively shortened.

As described above, in the present embodiment, the paint supply pipe
Results The amount of paint remaining decreases to 12, prevent the inner wall surface of the paint supply pipe 12 as in the prior art can prevent the paint layer is deposited, the to color mixing to the paint at the time extent next color painter In addition, beautiful painting can be reliably performed.

Further, even in the case of an electrostatic coating apparatus as in the prior art, the joint 16 can be easily changed to the joint 21 according to the present embodiment, and application to an existing coating machine can be easily performed. it can.

In the above embodiment, the spiral flow 2
5 is used as a joint of a paint supply pipe 12 for connecting the electrostatic coating machine 1 and the color changing valve device 11, but the present invention is not limited to this. The effect can be obtained even if it is used at an arbitrary end of the twelve joints.

The present invention is not limited to the bell type electrostatic coating apparatus, but can be used for disk type and gun type electrostatic coating apparatuses, and is not limited to the electrostatic coating apparatus.

[0042] Further, the fixation method of the joint 21 and the Ereme <br/> cement 24 paint tube, but limited to those using an adhesive not <br/> only, the ends of the element 24 to a pair of C-clip the axial direction of the cylindrical protrusion 22B from <br/> may perform fixing.

[0043]

As described in detail above, according to the present invention, the coating
Paint tubing that connects the paint supply device of the
A tubular joint body is formed at the end of the tube, and a paint or cleaning fluid on the supply side is formed by twisting the plate body, which is inserted and fitted in the joint body in the axial direction, and flows through the paint tube.
And an element formed to give a spiral flow to the paint tube, thereby making the flow in the paint tube downstream from the joint into a spiral flow, and
The flow near the inner wall in the tube can be accelerated. Soshi
Te, In extent painters, using this spiral flow
Thus, the amount of paint remaining near the inner wall surface of the paint tube can be reduced. Furthermore, the degree cleaning Engineering, the cleaning fluid can be washed out reliably before color paint remaining in the vicinity of the inner wall surface of the spiral flow coating tube, the amount of washing fluid used as washing Engineering and washing time Can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a paint tube joint according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing an element in FIG.

FIG. 3 is a left side view of the element in FIG. 2 as viewed from the left.

FIG. 4 is an overall configuration diagram showing a conventional rotary atomizing head type electrostatic coating apparatus.

[Figure 5] as painter, is a process explanatory view showing a more cleaning Engineering.

FIG. 6 is a cross-sectional view showing a paint layer remaining in a paint supply pipe.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrostatic coating machine 2 rotary atomizing head 11 color change valve device (paint supply device) 12 paint supply pipe (paint tube) 21 paint tube joint 22 joint body 24 element

Claims (1)

(57) [Claims] 1. A paint supply device for supplying a paint and a cleaning fluid.
A coating machine for spraying a coating material on an object to be coated;
Paint with a paint tube connecting between the
In the loading device, the end of the coating tube is connected to the coating device or the coating device.
A joint body formed in a tubular shape to be connected to a machine, and an axially inserted fitting body inside the joint body, and twisting the plate body to apply the coating.
Spiral of paint and cleaning fluid on the supply side flowing through the feed tube
A paint tube joint in a coating apparatus, comprising: an element formed so as to give a flow in a shape .