JPH0796220A - Electrostatic coating machine - Google Patents

Abstract

PURPOSE:To decrease loss of a coating and loss of a cleaning solvent cased by cleaning and decrease the cost of coating by providing a plurality of capillary nozzles in a tubular rotating shaft of an air motor built in a machine body of an electrostatic coating machine by insertion and driving independently opening and closing of each needle valve for them. CONSTITUTION:A plurality of capillary nozzle N0-N6 wherein nozzle holes 7 are opened and closed by means of needle 6 made of a wire each connected with each valve driving part S0-S6 provided in a machine body 2 are provided in parallel in a machine body 2 and the apexes of the nozzles N0-N6 are connected in the lump with a manifold 13 which inserts a feeding hole 13 for a coating into a tubular rotating shaft 4 under uncontacting condition and the rear ends of nozzles N0-N6 are respectively connected with the connecting holes P0-P6 coating hoses H0-H6 provided on the rear end side of the machine body 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a center feed type electrostatic coating for supplying paint from a tip opening portion of a tubular rotary shaft of an air motor incorporated in a machine body into a rotary atomizing head attached to the tip thereof. Regarding the machine.

[0002]

2. Description of the Related Art A center-feed type electrostatic coating machine includes an electrostatic coating machine 41 and a color changing device 42 as shown in FIG.
Are connected via a paint hose 43, and the paint hose 4
3 is connected to a thin tubular nozzle 46 inserted through a tubular rotary shaft 45 of an air motor 44, and the paint supplied from the paint hose 43 is atomized by rotation when a needle valve formed in the nozzle 46 is opened. The head 47 is electrostatically atomized for coating (see Japanese Utility Model Laid-Open No. 2-112353 and Japanese Utility Model Laid-Open No. 4-91754), and a vehicle body or the like that is successively conveyed by a conveyor is coated. When an object is painted with a paint of a designated color, the paint of a desired color is supplied from the color changing device 42 to the rotary atomizing head 47 for painting.

When the color change from the previous color paint to the next color paint is performed, the cleaning solvent supply valve 48 and the cleaning air supply valve 49 provided in the color changing device 42 are alternately opened and closed to clean the cleaning solvent and the cleaning solvent. By supplying air intermittently, the color changing device 42, the paint hose 43, the thin tubular nozzle 46
In addition, the previous color paint remaining and adhering to the rotary atomizing head 47 is washed and removed to prevent color mixture of the previous color paint and the next color paint.

By the way, in an actual coating line, the objects to be coated are not conveyed in the order of the coating colors, so that the objects to be continuously conveyed are continuously coated with the same color. There is almost no case, and the current situation is that the color is changed at a rate of about 8 to 9 times while coating 10 objects to be coated. For example, when the white coating is 50%, the red coating is 25%, and the blue coating is 25%, the colors are grouped as white-white-white-white-red-red-blue-blue. If it is transported, it is enough to change the color twice, but it is extremely rare that it will be transported in this way,
Normally, they are conveyed in any order, such as white-red-white-blue-white-red-white-blue, so the color is changed every time the coated object arrives.

[0005]

However, in order to prevent color mixing when changing colors, the previous color paint remaining in the paint hose 43 or the like is discarded every time cleaning is performed. As a result, not only does a huge paint loss occur, but also a large amount of cleaning solvent is required to clean the interior of the long paint hose 43, and tens of millions of yen of paint and solvent are thrown away in one stage per year. However, there is a problem that the coating cost increases.

In this case, if a plurality of thin tubular nozzles 46 can be inserted and arranged in the tubular rotary shaft 45, paint loss and washing solvent loss can be reduced, but the thin tubular nozzle 46 with a needle valve is provided. Even if you try to insert multiple
The inner diameter of the tubular rotary shaft 45 is limited, and there is also a limit to downsizing the opening / closing drive mechanism that individually opens and closes each needle valve. Therefore, in the end, a plurality of thin tubular nozzles 46 are installed in the tubular rotary shaft 45. It could not be inserted and arranged. Therefore, the present invention is a case in which the needle valves of a plurality of thin tubular nozzles inserted and arranged in the tubular rotary shaft of an air motor having a limited inner diameter can be individually opened and closed, and color change is performed every time. However, the technical issue is to reduce the paint cost and the cleaning solvent loss by cleaning so as to reduce the paint cost.

[0007]

In order to solve this problem, the present invention relates to a coating from a tip opening portion of a tubular rotary shaft of an air motor incorporated in an airframe to a rotary atomizing head attached to the tip thereof. In the electrostatic coating machine for supplying a plurality of thin tubular nozzles that open and close the nozzle holes with needles made of wire, which are respectively connected to the respective valve drive parts provided in the machine body, are arranged side by side in the machine body. The tip is collectively connected to a manifold that inserts the paint supply port into the shaft of the tubular rotary shaft in a non-contact state, and the rear end of each nozzle is connected to the connection port of each paint hose provided on the rear end side of the machine body. It is characterized by being connected to each other.

[0008]

According to the present invention, the nozzle holes of a plurality of thin tubular nozzles arranged side by side in the body are opened and closed by the wire needles connected to the valve drive parts such as the cylinder, the bellows, and the diaphragm. Even if the valve drive unit is provided near the outer periphery of the machine body, the nozzle hole can be reliably opened and closed with the needle bent. When the needle of the desired thin tubular nozzle is opened, the paint of the desired color supplied from the paint hose connected to the thin tubular nozzle is supplied from the paint supply port formed in the manifold into the rotary atomizing head. . Also,
Since each thin tubular nozzle is connected to the manifold at once, the paint remains only on the manifold and the rotary atomizing head,
Since the remaining amount is also small, it is sufficient to wash only the manifold and the rotary atomizing head at the time of color change washing, the paint loss and the washing solvent loss at the time of washing are small, and the washing time is shortened.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on the embodiments shown in the drawings. 1 is a sectional view showing an electrostatic coating machine according to the present invention, FIG. 2 is a sectional view taken along the line AA, and FIG. 3 is a rear view thereof.

Reference numeral 1 in the figure is an electrostatic coating machine for supplying paint from a tip opening of a tubular rotary shaft 4 of an air motor 3 incorporated in a machine body 2 into a rotary atomizing head 5 attached to the tip thereof. At the center of the machine body 2, cleaning solvent, cleaning air,
A thin tubular nozzle N ₀ that supplies paint of a color that is rarely used
Are arranged, and white, red, gray, and
The thin tubular nozzles N _{1 to} N ₆ for supplying a paint of a color frequently used such as blue are arranged side by side in a bundle.

Each of the thin tubular nozzles N _{0 to} N ₆ has a body 2
The nozzle holes 7 are opened and closed by the wire needles 6 connected to the cylinders (valve drive units) S _{0 to} S ₆ provided in the above. Specifically, each cylinder S ₀
The needle 6 is connected to the plunger 8 of S ₆ to S ₆ , and the plunger 8 is urged by the spring 9 in the direction of closing the nozzle hole 7, and the cylinder S _{0 is} supplied from the air supply port 10.
When compressed air is supplied into ~ S ₆ , the plunger 8 slides against the resilience of the spring 9 and the nozzle hole 7 is opened. Since the cylinders S _{0 to} S ₆ are thicker than the thin tubular nozzles N _{0 to} N _{6, the} other cylinders S _{1 to} S ₆ except the cylinder S ₀ that opens and closes the central thin tubular nozzle N ₀ are
The wires of the needles 6 are arranged near the outer circumference of the machine body 2 while being bent along the guide tube 11.

Further, the tip ends of the respective thin tubular nozzles N _{0 to} N ₆ are collectively connected to a manifold 13 which inserts the paint supply port 12 into the shaft of the tubular rotary shaft 4 in a non-contact state, and the nozzles are connected to each other. The hole 7 is opened in the manifold 13, and its rear end is connected to the connection ports P _{0 to} P ₆ of the paint hoses H _{0 to} H ₆ provided on the rear end side of the machine body 2, respectively. This paint hose H ₀ is a manifold of a color change valve device 15 provided with a cleaning solvent supply valve Vs, a cleaning air supply valve Va, and color change valves 14, 14, ... 16 and the paint hoses H _{1 to} H ₆ are connected to the paint supply source 17 for each dedicated color.

The above is an example of the configuration of the present invention, and its operation will be described below. For example, a case where the white paint supplied by the paint hose H ₁ is changed to the red paint supplied by the paint hose H ₂ will be described. First, when painting with white paint, compressed air is supplied to the cylinder S ₁ to slide the plunger 8 against the elastic force of the spring 9, and the needle 6 is pulled, and the nozzle of the thin tubular nozzle N ₁ is pulled. Since the hole 7 is opened, white paint is applied to the manifold 1.
3 is supplied to the rotary atomizing head 5 from the paint supply port 12 and electrostatically atomized to be applied to an object to be coated (not shown).

When the white paint is finished,
With the supply of compressed air to the cylinder S ₁ stopped and the thin tubular nozzle N ₁ closed, while the compressed air is supplied to the cylinder S ₀ and the central thin tubular nozzle N ₀ is opened, the color change valve device is provided. The cleaning solvent supply valve Vs and the cleaning air supply valve Va of 15 are alternately opened and closed to intermittently supply the cleaning solvent and the cleaning air into the manifold 13 through the paint hose H ₀ to clean and remove the remaining white paint.

In this case, only the inside of the manifold 13 and the rotary atomizing head 5 need be cleaned, so that the amount of cleaning solvent required for cleaning and the cleaning time are short, and the loss of white paint remains in them. Since it is just the amount that you do, the paint loss when changing colors is extremely small. When cleaning is completed,
Next, the supply of the compressed air to the cylinder S ₀ is stopped, the thin tubular nozzle N ₀ is closed, and when the object to be coated arrives, the compressed air is supplied to the cylinder S ₂ to feed the red paint. The nozzle N ₂ is opened and the next color paint is applied.

In the description of the embodiment, the case where the thin tubular nozzles N _{0 to} N ₆ are arranged by being inserted into the air motor 3 has been described, but the manifold 13 is provided at the rear end side of the air motor 3 and Alternatively, the paint supply port 12 may be extended to supply the paint from the tip of the tubular rotary shaft 4 into the rotary atomizing head 5. In this case, since only the paint supply port 12 is inserted into the air motor 3, the air motor 3 can be downsized. Further, the paint inlets P _{0 to} P ₆ to which the paint hoses H _{0 to} H ₆ are connected are not limited to being formed on the back surface of the machine body 2, but may be provided on the side surfaces. Further, the valve driving unit is not limited to the cylinders S _{0 to} S ₆ , but any means such as a diaphragm or a bellows which is reciprocally driven by a fluid pressure for a predetermined stroke can be adopted.

[0017]

As described above, according to the present invention, since the needles for opening and closing the nozzle holes of the thin tubular nozzles provided inside the body are made of wire, the valve drive unit is provided in the body. Even if it is arranged near the outer periphery of the nozzle, each thin tubular nozzle can be opened and closed by connecting it by bending the needle, and the paint discharged when each thin tubular nozzle is opened is passed through the manifold. Since it is supplied to the rotary atomizing head, it is not necessary to discard the paint in the paint hose even when changing colors every time, reducing the amount of paint that must be discarded by cleaning and the amount of cleaning solvent used for cleaning. Therefore, it has a very excellent effect that the coating cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an electrostatic coating machine according to the present invention.

FIG. 2 is a sectional view taken along the line AA.

FIG. 3 is a rear view thereof.

FIG. 4 is a flow sheet showing a conventional device.

[Explanation of symbols]

1 ... electrostatic coating machine 2 ... body 3 ... air motor 4 ... tubular rotary shaft 5 ... rotary atomizing head N ₀ to N ₆ ... fine tubular nozzle S ₀ to S ₆ · ... cylinder (valve drive unit) 6 ... needle 7 ... nozzle hole 12 ... paint supply port 13 ... manifold H ₀ to H ₆ ... hose P ₀ to P ₆ ... connecting port

Claims (1)

[Claims] 1. A static feed for supplying paint from a tip opening portion of a tubular rotary shaft (4) of an air motor (3) built in a machine body (2) into a rotary atomizing head (5) attached to the tip thereof. In the electric coating machine, a plurality of thin tubular nozzles for opening and closing the nozzle hole (7) by needles (6) made of wire respectively connected to valve drive units (S _{0 to} S ₆ ) provided in the machine body (2) (N _{0 to} N ₆ ) are arranged side by side in the machine body (2), and the tip of each nozzle (N _{0 to} N ₆ ) has a paint supply port (12) in the shaft of the tubular rotary shaft (4). The nozzles (N _{0 to} N ₆ ) are collectively connected to a manifold (13) that is inserted in a non-contact state, and the rear ends of the nozzles (N _{0 to} N ₆ ) are connected to the paint hoses (H ₀ to
An electrostatic coating machine characterized by being connected to the connection ports (P _{0 to} P ₆ ) of H ₆ ), respectively.