JPH0434909Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotary atomization type coating device equipped with a cleaning cover cylinder.

Conventionally, this type of painting equipment has attached a bell-shaped atomizing head that also serves as a charged electrode to the rotating shaft of an air motor.
A paint supply channel is connected to the base end of the atomizing head, a paint discharge part is formed at the tip of the atomizing head, and an annular air jetting device is connected to the air motor to eject air flow toward the outer circumference of the atomizing head. A valve is installed at the tip of the case to adjust the coating pattern to increase or decrease the flow rate of air ejected from the air ejection device. A cleaning cover tube is provided that can be moved back and forth to collect the cleaning agent. During painting, the cleaning cover tube is placed in a retracted position where the paint discharge part of the atomizing head protrudes from the front opening of the cleaning cover tube. The barrel is placed in an advanced position in which the paint discharge portion of the atomizing head is located.

However, during painting, even if the flow rate of the air jetted from the air jetting device is greatly increased or decreased from 0 to 500/min, the shape of the paint pattern remains in a donut-like annular shape, and the size of the paint pattern also increases. It does not change, and the adjustment range of the paint pattern is narrow. Needless to say, it is not possible to obtain a flat coating pattern such as an oval or dumbbell shape.

In addition to circular painting patterns such as annular and disk shapes, if a flat painting pattern can be obtained, less paint will be wasted when painting a rectangular area, and the efficiency of painting work will be increased. It gets expensive.

An object of the present invention is to provide a rotary atomizing coating device with a cleaning cover cylinder that can obtain a flat coating pattern in addition to a circular coating pattern and has a wide adjustment range of coating pattern.

In order to achieve the above object, the inventor of the present invention researched a method of controlling a coating pattern and found the following.

As shown in FIGS. 1 to 3, a pair of air outlets 27, 27 are provided at symmetrical positions sandwiching the atomizing head 8, and from both air outlets 27, 27, the tips of the atomizing head 8 are respectively When air is ejected obliquely forward toward the outer circumferential surface, the air ejected from each air outlet 27, 27 collides with the outer circumferential surface of the tip of the atomizing head 8, and flows forward or forward along the outer circumferential surface. flowing on both sides,
The air flowing to both sides collides with the air injected from the other air outlet 27 at a position intermediate between the two air outlets 27, 27 on the outer peripheral surface of the atomizing head 8, and flows forward. That is, the air ejected from each air ejection outlet 27, 27 covers half of the outer peripheral surface of the tip of the atomizing head 8, and flows forward as a fan-shaped air flow.

When the above-mentioned fan-shaped air flow is formed during painting, in which paint particles are emitted from the paint discharge part at the tip of the atomizing head by centrifugal force, the paint particles emitted from the paint discharge part are emitted from the two fans mentioned above. It is carried by a shaped air stream and flies forward, resulting in a flattened paint pattern, such as an oval or dumbbell shape.

In addition, if the fan-shaped air flow described above is high-speed,
Paint particles emitted by centrifugal force from the paint discharge part do not scatter in the radial direction, and paint does not adhere to the outer peripheral surface of the tip of the atomizing head or the tip of the cleaning cover cylinder. Therefore, paint defects such as spits do not occur.

In order to increase the speed of the fan-shaped air flow, the air outlet must be placed close to the outer peripheral surface of the tip of the atomizing head.

However, if the air outlet is placed close to the outer peripheral surface of the tip of the atomizing head, the air outlet will interfere with cleaning the atomizing head due to changes in paint color, etc. Not cleaned properly. Insufficient cleaning of the atomizing head will result in paint defects such as color mixing.

Another object of the present invention is to widen the adjustment range of the coating pattern in a rotary atomizing coating apparatus equipped with a cleaning cover tube without interfering with the cleaning of the atomizing head.

This invention widens the adjustment range of the coating pattern,
In addition, in order not to interfere with the cleaning of the atomizing head, in a rotary atomizing painting device with a cleaning cover tube, the atomizing head is placed at the front end of the cleaning cover tube from a symmetrical position between the atomizing head and the cleaning cover tube. This device is equipped with an air ejection device having a pair of air ejection ports that eject air diagonally forward toward the outer peripheral surface of the tip.

In this invention, when painting, when air is ejected from a pair of air ejection ports formed in the air ejection device, the coating pattern becomes flat, such as an ellipse or a dumbbell, as is clear from the above research results. Become. Furthermore, if air is not ejected from the pair of air injection ports, the coating pattern will be circular. Therefore, a flat coating pattern can be obtained in addition to a circular coating pattern, and the adjustment range of the coating pattern is wide.

Furthermore, during cleaning, the air jetting device having a pair of air jetting ports moves forward together with the cleaning cover cylinder and is placed in front of the atomizing head, so that it does not interfere with the cleaning of the atomizing head.

Next, embodiments of the present invention will be described.

1st Embodiment (See FIGS. 4 to 8) The rotary atomizing coating device with a cleaning cover cylinder of this example shown in FIGS. A hub 3 in which a disc part 5 is concentrically connected to the tip of a cylindrical part 4 is inserted into the rotating shaft 2, and the rotating shaft 2 of the air turbo motor is inserted into the tapered mounting hole 6 at the center of the disc part 5 of the hub. The hub 3 is concentrically attached to the rotating shaft 2 of the air turbo motor by a screw 7 passing through the center of the disk portion 5 of the hub with the tapered tip tightly fitted. The hub 3 has a bell-shaped body 8 in which a bowl-shaped cylindrical part 10 is concentrically connected to the tip of a cylindrical part 9.
The bell-shaped cylindrical part 9 is fitted onto the outer periphery of the cylindrical part 4 of the hub, and the bell-shaped bowl-shaped cylindrical part 10 is protruded to the front position of the hub 3, and the peripheral wall of the bell-shaped cylindrical part 9 is fitted. The bell shape 8 is concentrically attached to the hub 3 by screws 11 passing through the bell body 8. Integrated hub 3
and bell-shaped body 8 constitute an atomizing head. The atomizing heads 3 and 8 are connected to a DC high voltage generator (not shown) via the air turbo motor 1, and also serve as charging electrodes.

A paint supply pipe 12 connected to a paint supply device (not shown) is attached to the tip of the case of the air turbo motor 1, and the tip opening of the paint supply pipe 12 is placed inside the cylindrical portion 4 of the hub of the atomization head to perform atomization. A paint supply path 12 is connected to the hub 3 on the base end side of the head. A large number of paint passage holes 13 communicating with the bell-shaped bowl-shaped cylindrical portion 10 are penetrated through the distal end peripheral wall of the cylindrical portion 4 of the hub at equal intervals, and the inner peripheral surface of the bell-shaped bowl-shaped cylindrical portion 10 is penetrated. It is formed on the paint flow surface 14. At the tip of the paint flow surface 14, a paint distribution part 15 is formed, in which a large number of grooves are provided at equal intervals along the axial direction.
4, that is, the end opening edges of the atomizing heads 3 and 8 are used as a paint discharge portion 16.

A cleaning cover tube 17 in the shape of a tapered truncated cone is fitted concentrically around the outer circumferences of the atomizing heads 3 and 8 and the outer circumference of the tip of the air turbo motor 1. The distal end of an insulating material drive shaft 22 of a reciprocating drive device (not shown) is connected to the annular plate-shaped end plate 18 at the end, and the cleaning cover cylinder 17 is provided so as to be movable back and forth. A cleaning agent suction and discharge path 23 is connected to the lower part of the side peripheral wall.

An air blowing device 24 is provided on the front surface of the circular plate-shaped end plate 20 at the tip of the cleaning cover cylinder 17. The air blowing device 24 has a ring-shaped air passage 25 formed concentrically with the atomizing heads 3 and 8, and a high-pressure air supply via a flow control valve (not shown) for adjusting the coating pattern at the upper part of the air passage 25. 26 is connected.
At the upper and lower parts of the front surface of the air passage 25, as shown in FIGS. 5 and 6, there are air jet ports 27, each of which has two circular holes with a diameter of 1.8 mm placed close to each other in the upper and lower positions. An upper air outlet 27 at the front of the air passage 25 and an air outlet 27 at the lower front of the air passage 25 form a pair of upper and lower air outlets 27. Sometimes,
It is configured to open diagonally forward from upper and lower symmetrical positions sandwiching the atomizing heads 3 and 8 toward the upper and lower portions of the outer peripheral surface of the atomizing head tip.

The front end opening 21 of the cleaning cover cylinder is formed by the inner circumferential surface of the annular air blowing device 24 and the inner circumferential surface of the annular plate-shaped end plate 20 at the tip of the cleaning cover cylinder.
The diameter is slightly larger than the maximum outer diameter of the atomizing heads 3 and 8, and the base end opening 19 of the cleaning cover cylinder has an even larger diameter.

When the painting apparatus of this example is driven to perform painting, first, the cleaning cover cylinder 17 is moved as shown in FIG.
The paint discharging portion 16 of the atomizing head is retracted to a position where it protrudes from the front end opening 21 thereof.

Note that the distance L from the opening surface of the air jetting port 27 of the air jetting device to the opening surface of the paint discharge portion 16 of the atomizing head is 20 mm.

Next, the atomizing heads 3 and 8 rotate at high speed, and a DC high voltage is applied between the atomizing heads 3 and 8, which also serve as charged electrodes, and an object to be coated (not shown) placed in front of the atomizing heads 3 and 8. High pressure air is supplied to the air passage 25, air is ejected diagonally forward from each air outlet 27, and paint is supplied from the paint supply path 12 into the hub 3 of the atomizing head.

The paint supplied into the hub 3 of the rotating atomizing head passes through a large number of paint passage holes 13 into the bell-shaped bowl-shaped cylinder part 10 due to centrifugal force, and the paint flows in the bowl-shaped cylinder part. The paint flows in the form of a thin film on the surface 14, flows into the many grooves of the paint distribution section 15, and is discharged radially from the paint discharge section 16, where it is atomized into fibrous particles. The paint particles emitted from the paint discharge part 16 of the atomizing head are affected by the force of the fan-shaped air flow that is ejected forward from each air outlet 27 along the outer peripheral surface of the tips of the atomizing heads 3 and 8, and the paint particles. Due to the electrostatic attraction acting between the particles and the object to be coated, the particles fly in a forward direction and adhere to the object to be coated.

When adjusting the coating pattern, the flow rate of air supplied to the air passage 25, that is, the flow rate of air jetted from the air injection port 27, is increased or decreased.

The relationship between the shape and dimensions of the coating pattern and the above-mentioned air flow rate is as shown in FIGS. 7 and 8. The coating pattern is such that when the air flow rate is zero, the outer diameter is approximately
It becomes an annular shape of 9.0cm, but the air flow rate is 500/min.
When , the length is about 70cm as shown in Figure 8.
It becomes a dumbbell-like or cocoon-like flat shape.

It should be noted that no coating particles were observed to adhere to the outer circumferential surfaces of the atomizing heads 3 and 8, the air blowing device 24, or the cleaning cover cylinder 17 at any air flow rate.

If the distance L from the opening surface of the air injection port 27 to the opening surface of the paint discharge part 16 is shortened, the paint discharge part 1
The speed of the airflow passing through the outer circumferential position of 6 becomes higher, but the outer peripheral surface of the atomizing heads 3 and 8, the air jet device
The above distance L should be 1 to 60 mm, especially 5 to 60 mm, since coating particles tend to adhere to the tip of the cleaning cover tube 17.
30mm is preferred.

When cleaning is performed by driving the coating device of this example, the cleaning cover cylinder 17 is moved by the forward drive of the reciprocating drive device (not shown), as shown in FIG. Thereafter, a cleaning solvent or air, that is, a cleaning agent, is injected through the paint supply path 12 into the rotating atomizing head hub 3 to which no DC high voltage is applied.

Similar to the paint during painting, the cleaning agent injected into the hub 3 of the rotating atomizing head is moved by centrifugal force to the paint passage hole 13, the paint flow surface 14, and the paint distribution part 15.
The paint is emitted from the paint discharging section 16 through the process, during which time the inner surfaces of the atomizing heads 3 and 8 are cleaned. The cleaning agent emitted from the paint discharge part 16 collides with the inner peripheral surface of the cleaning cover tube 17, is collected at the lower part of the base end side of the cleaning cover tube 17, and is discharged through the cleaning agent suction and discharge path 23. be done.

In the coating device of this example, the air blowing device 24
is provided at the front end of the cleaning cover tube 17, so that it is placed in front of the atomizing heads 3, 8 as the cleaning cover tube 17 moves forward during cleaning, as shown in FIG. Therefore, the air blowing device 24 does not interfere with the cleaning of the atomizing heads 3 and 8.

Second Embodiment (See Figures 9 to 14) Compared to the previous example, the rotary atomizing coating device with a cleaning cover tube of this example has a higher level of mist as shown in Figures 9 and 10. In composing Kato 3 and 8,
A cylindrical body 8 in which a rear cylindrical portion 9 and a front cylindrical portion 10 are concentrically arranged is used in place of the bell shape in the previous example. In addition, on the front surface of the circular plate-shaped end plate 20 at the tip of the cleaning cover cylinder 17, the air blowing device 2 in the previous example is provided.
In addition to the second air blowing device 36 for the flat pattern corresponding to No. 4, a first air blowing device 31 for the circular painting pattern is provided.

As shown in FIGS. 9 and 10, the first air blowing device 31 includes an annular component 32 attached to the front surface of the annular plate-shaped end plate 20 at the tip of the cleaning cover cylinder 17, and a circular component 32 installed inside the component 32. An annular air passage 33 is formed concentrically with the atomizing heads 3 and 8, and a high-pressure air supply passage 34 is connected to the side of the air passage 33 through a flow control valve (not shown) for adjusting the coating pattern. , 33 air nozzles 35 with a diameter of 0.6 mm are bored in the front of the air passage 33 at equal intervals in a circular ring concentric with the atomizing heads 3 and 8, and each air nozzle 35 is slightly spaced toward the center. It is slanted and opens at the front. When painting, the air
The air passes through the outer side of the tips of the atomizing heads 3 and 8 and is ejected forward from the air jet ports 35 arranged in an annular shape.

As shown in FIGS. 9 and 10, the second air injection device 36 has component blocks 37 attached to the upper and lower ends of the component 32 of the first air injection device, respectively, and air passages in both component blocks 37. 3
8, and a high-pressure air supply path 39 is connected to the outer side of both air passages 38, with a flow rate control valve (not shown) interposed therebetween for adjusting the coating pattern. 9 and 1 on the front of the inner surface of both the upper and lower air passages 38.
As shown in Figure 0, air jet ports 40 each having two 1.4 mm diameter circular holes placed close to each other in the upper and lower positions are provided, and the air jet ports 40 in the upper air passage 38 and the lower air jet ports 40 are provided. The air nozzles 40 of the air passage 38 constitute a pair of upper and lower air nozzles 40, and the upper and lower pair of air nozzles 40 are connected to the atomizing head 3,
The atomizing head is configured to open diagonally forward from a symmetrical position in the upper and lower sides with 8 in between, toward the upper and lower parts of the outer circumferential surface of the tip of the atomizing head.

Other points are the same as those in the previous example, so the same reference numerals are given to FIGS. 9 and 10, and the explanation thereof will be omitted.

When adjusting the coating pattern, the flow rate of the first air jetted out from the air jetting port 35 of the first air jetting device and the flow rate of the second air jetted out from the air jetting port 40 of the second air jetting device are increased or decreased.

The relationship between the shape and dimensions of the coating pattern and the above-mentioned first air flow rate and second air flow rate is shown in Figures 11 to 14.
As shown in the figure.

When the first air flow rate and the second air flow rate are zero, the coating pattern becomes an annular shape with an outer diameter of approximately 90 cm.
Further, when the first air flow rate is 200/min and the second air flow rate is zero, it becomes a disk shape with a diameter of about 40 cm.
However, when the first air flow rate is zero and the second air flow rate is
At 300/min, as shown in Figure 13,
It has a dumbbell-like or cocoon-like flat shape with a length of about 60 cm, and when the first air flow rate is 200/min and the second air flow rate is 300/min, the 14th
As shown in the figure, it has an elliptical flat shape with a major axis of about 50 cm.

As is clear from the above relationship, when the first air flow rate is increased, the coating pattern approaches a small-diameter disk shape, and when the second air flow rate is increased, the paint pattern approaches an elongated flat shape.

In both of the embodiments shown above, the air outlet 2
The number, size, shape, and arrangement position of the circular holes 7 and 40 are as described above, but are not limited to these.

Further, although the coating device is an electrostatic type, it is not limited to this.

[Brief explanation of drawings]

1 to 3 are schematic diagrams showing the flow state of air ejected from the air outlet in the present invention. FIG. 1 is a side view, FIG. 2 is a front view, and FIG. 3 is a plan view. FIG. 4 is a partially longitudinal sectional side view of a rotary atomizing coating device with a cleaning cover cylinder according to the first embodiment of the present invention. FIG. 5 is a front view of the device. FIG. 6 is a partially longitudinal side view showing the state of the device during cleaning. Figures 7 and 8 are
It is a schematic diagram showing a coating pattern in the same device.
FIG. 9 is a partially longitudinal side view of a rotary atomizing coating apparatus with a cleaning cover cylinder according to the second embodiment. FIG. 10 is a front view of the device. Figures 11 to 14
The figure is a schematic diagram showing a coating pattern in the same apparatus. 1... Air turbo motor, rotary drive device, 2...
... Rotating shaft, 3, 8 ... Atomization head, 12 ... Paint supply pipe, paint supply path, 16 ... Paint discharge part, 17 ...
Cleaning cover cylinder, 21... Front end opening, 24... Air jetting device, 27... Air jetting port, 31... First air jetting device, 35... Air jetting port, 36... Second
Air blowout device, 40...air blowout port.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. An atomizing head is attached to the rotating shaft of the rotary drive device, a paint supply path is connected to the base end of the atomizing head, a paint discharge part is formed at the tip of the atomizing head, and the paint is An air blowing device is provided that blows out an air flow that bends the paint particles emitted from the discharge part forward, and a paint pattern adjustment means is provided to increase or decrease the flow rate of the air blowing out from the air blowing device, A cleaning cover tube is installed that can be moved back and forth to collect the cleaning agent emitted from the paint discharge part of the atomizing head. In a rotary atomizing painting device with a cleaning cover tube configured to be placed in a retracted position where the paint discharge part protrudes and in a forward position in which the paint discharge part of the atomizing head is placed during cleaning, the above-mentioned An air blowing device is installed at the front end of the cleaning cover cylinder, and the air blowing device blows air diagonally forward from a symmetrical position across the atomizing head toward the outer peripheral surface of the tip of the atomizing head during painting. A rotary atomizing coating device with a cleaning cover cylinder, characterized in that a pair of air outlets are formed to eject air. 2 In addition to the air blowing device in which the pair of air blowing ports are formed at the front end of the cleaning cover cylinder,
A utility model characterized in that an air jetting device is provided in which an annular air jetting port is formed concentrically with the atomizing head and blows air forward through the outside position of the atomizing head tip during painting. A rotary atomizing coating device with a cleaning cover cylinder as claimed in claim 1.