JP5037973B2 - Painting machine - Google Patents

Description

  The present invention relates to a coating machine having a paint pressurizing mechanism that presses a pre-filled paint against an atomizing mechanism, and particularly to an electrostatic coating machine that electrostatically atomizes a conductive paint such as a water-based paint. And suitable.

  In automobile body painting, paints using organic solvents are the mainstream, but from the viewpoint of environmental protection and pollution prevention, it is required to reduce volatile organic solvents generated in large quantities in the painting process. As a result, painting with water-based paint has attracted attention.

  In order to use water-based paint without waste, it is preferable to apply with an electrostatic coating device with high coating efficiency. However, water-based paint has low electrical resistance, and the electrostatic coating machine uses paint that flows through the paint supply system. Since the rotary atomizing head and the ground side are easy to conduct, it is necessary to take insulation measures for the entire paint supply system to prevent leakage of a high voltage of −60 to 90 kV applied to the rotary atomizing head.

For this reason, conventionally, the paint supply system is formed by filling the paint filling tank, which is formed in the paint machine or detachably attached to the paint machine, and presses the paint from the tank and paints it. It is electrically cut off so that it does not leak even when a high voltage is applied to the coating machine.
JP 2000-317354 A

  In this type of electrostatic coating machine, a bottom plate that serves as a piston is usually slidable along the inner peripheral surface of a replacement tank that serves as a cylinder, and the bottom plate is pressed by another actuator or hydraulic pressure. The paint is pressed out.

  However, in this case, since the sealing between the bottom plate and the inner peripheral surface must be performed securely, the friction is increased and a large driving force is required, and the seal is rubbed and worn each time the bottom plate reciprocates. In the case of hydraulic driving, the hydraulic fluid may flow and adversely affect the coating quality.

  In addition, the normal seal has a structure in which a plurality of O-rings are arranged in parallel on the outer peripheral surface of the bottom plate that serves as a piston, so that paint enters between the O-rings and the O-rings, and the daily work is performed. When the cleaning is completed, the bottom plate must be removed and disassembled for cleaning.

For this reason, the present applicant made a trial production of a coating machine 51 as shown in FIG.
According to this, the paint bag 52 filled with the paint is provided in the replacement tank (paint pressure chamber) 53 filled with the hydraulic fluid, and is formed at the tip of the hydraulic fluid supply / discharge pipe 54 inserted into the replacement tank 53. The hydraulic fluid is introduced from the hydraulic fluid inlet / outlet 54a, and the coating material bag 52 is crushed and crushed by the hydraulic pressure, whereby the coating material is pressed out.
JP 2006-347606 A

According to this, when the paint bag 52 is filled with paint in advance and the working fluid is allowed to flow into the replacement tank 53 in a fixed amount, for example, the paint bag 52 is crushed by the liquid pressure and the paint is pressed out in a fixed amount. Then, the air is supplied through a feed pipe 58 to a rotary atomizing head (atomizing mechanism) 57 attached to the tip of the tubular rotary shaft 56 of the air motor 55.
Accordingly, since there is no influence of friction due to the O-ring, the pressure of the working fluid acts on the paint as it is, and the paint can be supplied to the atomizing mechanism with a relatively small driving force.
Further, since the bottom plate serving as the piston is not used, cleaning can be easily performed without a gap between the bottom plate and the replacement tank 53, and cleaning defects and coating defects due to seal leakage of the bottom plate are eliminated.
Furthermore, since the hydraulic fluid inflow / outflow port 54a is formed at the tip of the hydraulic fluid supply / discharge tube 54 inserted to the back of the replacement tank 53, the hydraulic fluid inflow / outflow port 54a is blocked even if the coating material bag 52 is inflated by filling with the coating material. Therefore, no malfunction occurs.

By the way, if the same paint bag 52 is used for a long time, the paint bag 52 may be broken during use due to fatigue. Therefore, when the paint tank 52 is filled with paint by removing the replacement tank 53, the replacement tank 53 is used. The change in the color of the hydraulic fluid discharged from the liquid is optically monitored to detect the tear of the paint bag 52.
However, the paint bag 52 hardly ruptures normally, and usually only a very small crack is formed, so that a large amount of paint is not mixed with the hydraulic fluid, so that it takes time to find it even if the paint bag 52 is torn. There was a problem.
In particular, the hydraulic fluid inflow / outflow port 54a is formed at the tip of the hydraulic fluid supply / discharge pipe 54 inserted to the back of the replacement tank 53 so that the coating bag 52 is not blocked by expansion / contraction. When the bag 52 is torn and paint is mixed into the hydraulic fluid, the turbid hydraulic fluid will not flow out as soon as it stagnates on the bottom side 53b side of the hydraulic fluid pressure chamber 53 due to the specific gravity, etc. When it flows out of the pipe 54, there is a possibility that a considerable amount of time has already passed and the working fluid has flowed into the paint bag 52, resulting in poor painting.

  Therefore, the present invention has a technical problem to be able to quickly detect even if a paint bag is torn when the paint bag is extruded and applied.

In order to solve this problem, the present invention provides a coating machine provided with a paint pressurizing mechanism that presses a prefilled paint against an atomizing mechanism, wherein the paint pressurizing mechanism is a paint bag filled with paint. Is placed in the paint pressure chamber filled with hydraulic fluid, communicated with the atomizing mechanism via the paint inflow / outlet port, and the paint pressure is discharged from the hydraulic fluid inflow / outlet of the hydraulic fluid supply / discharge pipe inserted into the paint pressure chamber. A hydraulic fluid supply / discharge system that compresses the paint in the paint bag by crushing the paint bag with the fluid pressure of the hydraulic fluid flowing into the chamber, and the hydraulic fluid inflow / outflow port supplies the hydraulic fluid to the paint pressure chamber. It is characterized in that it is formed on the peripheral surface of the hydraulic fluid supply / discharge pipe in such a direction as to blow in the circumferential direction along the inner wall .

  In the coating machine according to the present invention, when the paint bag is filled with paint such as paint and the working fluid is allowed to flow into the paint press-out chamber, the paint bag is crushed by the fluid pressure, and the paint is squeezed out in a fixed amount. Supplied to the atomization mechanism.

At this time, since the hydraulic fluid inlet / outlet is formed not on the tip of the hydraulic fluid supply / discharge pipe but on the peripheral surface, the hydraulic fluid flows out in a direction perpendicular to the hydraulic fluid supply pipe, Flow to stir.
Therefore, since the working fluid is totally turbid when the paint bag is torn and the paint flows out, it is possible to quickly detect that the paint bag has been torn.

Here, if the hydraulic fluid inlet / outlet is formed on the peripheral surface and the tip of the hydraulic fluid supply / discharge pipe as in the second aspect, the hydraulic fluid is not blocked by the paint bag.
Further, a plurality of hydraulic fluid inlets / outlets are formed at a predetermined interval on the peripheral surface of the hydraulic fluid supply / exhaust pipe as in claim 3, or the hydraulic fluid inlet / outlet is at the root of the hydraulic fluid supply / exhaust pipe as in claim 4. If the hydraulic fluid inflow / outflow port that blows out the hydraulic fluid in the circumferential direction along the inner wall of the paint press-out chamber is connected to the hydraulic fluid supply pipe as in claim 5, the hydraulic fluid is more reliably supplied. Stir.

  In order to achieve the object of the present invention, it is possible to quickly detect a paint bag even if the paint bag is torn, when the paint bag is extruded and applied. A hydraulic fluid inlet / outlet was formed on the peripheral surface of the hydraulic fluid supply / discharge pipe inserted into the outlet chamber so that the hydraulic fluid could be stirred in the paint pressurizing chamber.

Hereinafter, a coating machine according to the present invention will be specifically described with reference to the drawings.
FIG. 1 is an explanatory view showing an example of a coating machine according to the present invention, FIG. 2 is a cross-sectional view thereof, and FIGS. 3 and 4 are explanatory views showing other embodiments.

  An electrostatic coating machine 1 shown in FIG. 1 performs electrostatic coating of a conductive paint such as a water-based paint. A rotary atomizing head (atomization mechanism) 3 that rotates and atomizes the paint on the front end side of the machine body 2 is provided. A cylindrical replacement tank (paint pressurizing chamber) having a paint pressurizing mechanism P for pumping out prefilled paint with hydraulic pressure of hydraulic fluid and supplying it to the rotary atomizing head 3 at its rear end side. ) 4 is detachably mounted.

  The rotary atomizing head 3 is attached to a tubular rotary shaft 6 of an air motor 5 arranged in the airframe 2 and is driven to rotate at high speed, and atomizes the paint supplied from the exchange tank 4 through the feed pipe 7. A high voltage supplied from a high voltage generator (not shown) built in the coating machine 1 is applied to charge the atomized paint particles to the opposite electrode to the object to be coated.

The paint pressurizing mechanism P is disposed in the exchange tank 4 in which the paint bag 8 for filling the paint is filled with the working fluid, and communicates with the atomizing mechanism through the paint inflow / outlet 8a.
Further, a hydraulic fluid supply / discharge system 9 that supplies / discharges hydraulic fluid to / from the replacement tank 4 is provided, and hydraulic fluid inlets / outlets 10 a to 10 f formed in the hydraulic fluid supply / discharge pipe 10 inserted into the replacement tank 4. Then, the paint bag 8 is crushed and crushed by the fluid pressure of the hydraulic fluid flowing into the replacement tank 4 so that the paint in the paint bag 8 can be discharged and fed to the rotary atomizing head 3.

The hydraulic fluid supply / discharge pipe 10 has a hydraulic fluid inlet / outlet port 10a formed at the tip thereof, and a plurality of hydraulic fluid inlet / outlet ports 10b to 10f formed at predetermined intervals from the tip side to the root along the peripheral surface. Yes.
Moreover, the hydraulic fluid inflow / outflow ports 10b to 10f formed on the peripheral surface are formed in a direction in which the hydraulic fluid is blown in the circumferential direction along the inner wall of the exchange tank 4 (see FIG. 2).
Therefore, since the working fluid is stirred in the exchange tank 4 when supplying the working fluid, the paint and the working fluid that leaked when the paint bag 4 is torn are easily mixed and become cloudy. Then, it can be discovered quickly when detecting a tear.

A joint 11A connected to the body 2 of the coating machine 1 is formed at the front end side of the exchange tank 4, and a paint port to which the paint inflow / outflow port 8a of the paint bag 8 is connected in the tank 4 is connected to the joint 11A. 12 and a hydraulic fluid port 13 communicating with the hydraulic fluid supply / discharge pipe 10 are formed.
The joint base 11B on the side of the machine body 2 connected to the joint 11A of the replacement tank 4 is formed with a paint port 14 communicated with the feed pipe 7 and a hydraulic fluid port 15 communicated with the hydraulic fluid piping 16. Yes.
The ports 14 and 15 on the airframe 2 side are engaged with the ports 12 and 13 on the tank 4 side, and a stop valve that is opened when engaged is built in each port 12 to 15. Has been.

Further, a cleaning port 17 formed on the side surface of the machine body 2 is connected to the paint port 14 via a cleaning liquid pipe 18 so that the paint remaining on the feed pipe 7 and the rotary atomizing head 2 can be cleaned and removed.
The paint port 14 is a three-way valve with a stop valve. When the paint port 14 is engaged with the paint port 12 of the tank 4, the cleaning liquid pipe 18 is shut off and the paint bag 8 is communicated with the feed pipe 7. When the engagement of the port 12 is released, the connection port with the paint port 12 is closed, and the cleaning liquid pipe 18 is communicated with the feed pipe 7.

The above is one configuration example of the present invention, and the operation thereof will be described next.
Various operating air pipes, exhaust pipes, and power cables (all not shown) are connected to the body 2 of the electrostatic coating machine 1 and attached to a weaving arm of a painting robot (not shown).
Then, the replacement tank 4 filled with the paint bag 8 is mounted on the machine body 2 at a predetermined mounting position, the rotary atomizing head 3 is driven to rotate at a high speed by the air motor 5, and a high voltage generator (not shown) is connected. Turns on and applies a high voltage, and moves the coating machine 1 to an arbitrary coating position.

Then, when painting, when a constant amount of hydraulic fluid is supplied from the machine body 2 to the replacement tank 4 via the hydraulic fluid pipe 16, the hydraulic fluid formed in the hydraulic fluid supply / discharge pipe 10 inserted into the paint tank 4. The working fluid flows into the paint tank 4 from the inflow / outflow ports 10a to 10f.
Since the hydraulic fluid inflow / outflow ports 10b to 10f formed on the peripheral surface are formed in a direction in which the hydraulic fluid is blown in the circumferential direction along the inner wall of the replacement tank 4, the hydraulic fluid is forced to convection in the circumferential direction in the tank 4. Then, the paint bag 8 is crushed and crushed while the inside is stirred with the hydraulic fluid.
As a result, the paint in the paint bag 8 is pressed out and supplied to the rotary atomizing head 3 via the feed pipe 7 where it is electrostatically atomized.
In this case, even if a conductive paint is used as the paint, the paint is filled in the paint bag 8 and is not electrically connected to the outside through the conductive paint, so that a high voltage leaks. Therefore, there is no need to take insulation measures for the paint supply system (not shown) for filling the paint filling tank 4 with paint.

  When the painting is completed, the coating machine 1 is returned to the mounting position and the replacement tank 4 is removed. At the same time, the cleaning liquid is supplied from the cleaning liquid port 17 and the paint remaining inside the machine body 2 is cleaned and removed, and the paint bag is filled. The tank 4 filled with paint is mounted, and painting is performed again at an arbitrary painting position.

Therefore, instead of sliding the bottom plate of the replacement tank and starting to press the paint as in the conventional case, the paint bag 8 can be crushed and the paint can be pressed out by flowing the hydraulic fluid into the outside of the paint bag 8. Therefore, there is an effect that the pressure of the working fluid acts on the paint as it is, and the paint can be pressed out with a relatively small driving force.
Further, since the paint is filled in the paint bag 8 and is completely separated from the working fluid, it is not necessary to provide a seal for preventing them from mixing with each other, and a coating failure due to seal leakage occurs. Further, there is no wrinkle, and furthermore, there is no gap for the paint to enter, so there is an effect that cleaning can be easily performed.

When the paint bag 8 is torn, the paint leaks out and mixes with the hydraulic fluid.
If it breaks when supplying the hydraulic fluid and pressurizing the paint, the leaked paint is agitated by the convective hydraulic fluid and mixes well with the hydraulic fluid, and the hydraulic fluid becomes cloudy.
In addition, if the replacement tank 4 is removed from the machine body 2 and is torn when the paint is filled, the leaked paint mixes with the working fluid directed to the respective working fluid inflow ports 10a to 10f, and the working fluid becomes cloudy.

In any case, the turbid hydraulic fluid is discharged by forced convection toward the hydraulic fluid inflow / outflow ports 10a to 10f when the paint is filled.
At this time, no matter which part of the paint bag 8 is torn or the leaked paint and the working fluid are not well mixed, the working fluid supply / discharge pipe 10 has the working fluid inlet / outlet ports 10a to 10f. Since they are provided at predetermined intervals, the hydraulic fluid mixed with the paint is surely discharged from any of the hydraulic fluid inflow / outflow ports 10a to 10f and does not stay in the paint tank 4.
Therefore, it is possible to quickly detect the tear of the paint bag by optically detecting the turbidity of the hydraulic fluid that flows out.

The present invention is not limited to the case where a large number of hydraulic fluid inlets / outlets 10a to 10f are provided as described above, but as shown in FIG. 10a and 10f may be provided.
In particular, when the specific gravity of the paint is heavier than that of the working fluid, the paint that leaks when the paint bag 8 is torn is likely to stagnate in the bottom of the tank 4, so it is effective to provide at least one working fluid inlet / outlet 10 f at the base side. It is.

4A and 4B are a transverse sectional view and a longitudinal sectional view showing another embodiment of the present invention.
The coating machine 21 of this example is buried in the inner peripheral surface 24 of the tank 23 so that the hydraulic fluid supply / discharge pipe 22 does not protrude into the replacement tank 23, and the hydraulic fluid inflow / outflow ports 22 a to 22 f are tangential to the inner peripheral surface 24. The configuration is the same as that of the coating machine 1 shown in FIG.
In the coating machine 21 of this example, since the hydraulic fluid supply / discharge pipe 22 does not protrude into the replacement tank 23, the hydraulic oil supply / discharge pipe 22 may be damaged when the paint bag 8 is filled with the paint and swells. There is a merit that there is no.

  INDUSTRIAL APPLICABILITY The present invention is suitable for use in a type of coating machine in which a paint bag is crushed from the outside of a flexible paint bag filled with paint in advance by hydraulic pressure of hydraulic fluid and the paint is pressed.

Explanatory drawing which shows an example of the coating machine which concerns on this invention. FIG. Explanatory drawing which shows other embodiment. Explanatory drawing which shows other embodiment. Explanatory drawing which shows a conventional apparatus.

Explanation of symbols

1,21 Coating machine 2 Airframe 3 Rotating atomizing head (Atomizing mechanism)
P Paint pressure mechanism 4, 23 Replacement tank (Paint pressure chamber)
8 Paint Bag 8a Paint Inlet / Outlet 9 Hydraulic Fluid Supply / Discharge System 10, 22 Hydraulic Fluid Supply / Discharge Pipe
10a to 10f, 22a to 22f Working fluid inlet / outlet

Claims (4)

In a coating machine equipped with a paint press-out mechanism that presses a pre-filled paint against the atomization mechanism,
The paint pressurizing mechanism is disposed in the paint pressurizing chamber filled with the working fluid with the paint bag filled with the paint, communicated with the atomizing mechanism through the paint inflow / outlet, and inserted into the paint pressurizing chamber. A hydraulic fluid supply / discharge system for compressing the paint in the paint bag by crushing the paint bag with the fluid pressure of the hydraulic fluid flowing into the paint pressure discharge chamber from the hydraulic fluid inlet / outlet of the hydraulic fluid supply / discharge pipe; A coating machine , wherein a working fluid inflow / outflow port is formed on a peripheral surface of the working fluid supply / discharge pipe in a direction in which the working fluid is blown out in a circumferential direction along an inner wall of a paint pressurizing chamber .   The coating machine according to claim 1, wherein the hydraulic fluid inlet / outlet is formed on a peripheral surface and a tip of the hydraulic fluid supply / discharge pipe.   The coating machine according to claim 1, wherein a plurality of the hydraulic fluid inlet / outlet are formed at predetermined intervals on a peripheral surface of the hydraulic fluid supply / discharge pipe.   The coating machine according to claim 1, wherein the hydraulic fluid inlet / outlet is formed with an opening at least at the base of the hydraulic fluid supply / discharge pipe.

Images