JPS5938822B2 - electrostatic coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a rotary cup rotating drive part of an electrostatic coating device, in which a rotary shaft 2 having a rotary cup 1 attached to one end for electrostatically atomizing paint is mounted inside a main body 3. The rotary shaft 2 is provided with a vane 5 which is rotatably inserted into the rotary shaft 2 and rotates the rotary shaft 2 by receiving air pressure in the drive chamber 4 of the main body 3 into which air is introduced. A bearing 6 that pivotally supports the rotating shaft 2 is interposed therebetween, and an air retention chamber □ is formed between the rotating shaft 2 and the main body 3 at a position opposite to the drive chamber 4 of the bearing 6.
An electrostatic coating device characterized in that a communication passage 8 is connected between a drive chamber 4 and an air retention chamber 1 is defined as a specified invention,
A rotating shaft 2 equipped with a rotating cup 1 for electrostatically atomizing paint at one end is rotatably inserted into the main body 3, and the rotating shaft receives air pressure in the drive chamber 4 of the main body 3 into which air is introduced. A blade 5 for rotationally driving the rotating shaft 2 and the main body 3 is provided on the rotating shaft 2.
A bearing 6 that pivotally supports the rotating shaft 2 is interposed between the rotating shaft 2 and the main body 3 at a position opposite to the drive chamber 4 of the bearing 6.
An air retention chamber 1 communicating with the drive chamber 4 is formed between the rotary shaft 2 and the main body 3, and a minute gap 21 is formed between the rotating shaft 2 and the main body 3 through which the air retention chamber □ communicates with the outside. The purpose is to prevent grease from flowing out from the bearing that supports the rotating shaft due to the air pressure of the air that drives the rotating shaft. To provide an electrostatic coating device that is free from fear.

The present invention will be explained in detail below with reference to Examples.

In FIG. 1, reference numeral 1 denotes a rotary cup made of metal such as aluminum that atomizes paint using static electricity and sprayed air. It is formed by attaching the body 11 to the outer circumferences of the front cylinder body 10 and the rear cylinder body 9, and is fitted and attached to the tip of the rotating shaft 2. The rear cylinder body 9 is provided with a plurality of communication holes 13 that communicate with the air passage 12 provided at the axial center of the rotating shaft 2. The communication holes 13 are formed between the front cylinder body 10 and the outer cylinder body 11 It communicates with an annular air chamber 14. A paint dispersion cup 15 is attached to the tip of the rotary shaft 2 protruding forward from the rear cylinder 9 on the inner periphery of the front cylinder 10, and a large number of paint outlets 16 are perforated on the outer periphery of the paint distribution cup 15. It has been done. The front cylinder 10 has an inner peripheral surface whose diameter gradually increases in a tapered manner toward the front, and the rear end of the front cylinder 10 communicates with the rear cylinder 9 through a tunnel portion 17. Further, a knife edge portion 18 is formed at the tip of the front cylinder body 10 by making the taper slope even steeper. The main body 3 is formed by fixing a casing 21 between a base body 19 and a front body 20 with bolts 22, as shown in FIG. 4 is formed within the main body 3.
The rotating shaft 2 is rotatably attached to the main body 3 by passing through the front body 20 and the base body 19, and the drive chamber 4
Bearings 6, such as ball bearings, installed on both sides of the
6 is interposed between the main body 3 and the rotating shaft 2, so that the rotating shaft 2 is pivotally supported by the bearing 6. Further, on the opposite side of the drive chamber 4 of the bearings 6, 6, annular air retention chambers 7, 7 are formed between the rotating shaft 2 and the main body 3.
is communicated with the drive chamber 4 through a communication passage 8 bored in the main body 3. The air storage chamber 7 and the communication passage 8 constitute an air balance means. 5 is. A blade such as a Shirotsuko fan attached to the outer periphery of the rotating shaft 2 in the drive chamber 4, 23 is a nut that prevents the rotating shaft 2 from coming off, 24 is a nozzle for blowing compressed air into the drive chamber 4, and 25 is the drive chamber 4.
26 is a protective nut screwed onto the outer periphery of the rotating shaft 2 to prevent paint, thinner, etc. from flowing into the main body 1. .

Further, a minute gap 27 is formed between the rotating shaft 2 and the main body 3 and communicates with the air retention chamber 7, and the minute gap 27 of the front body 20 is formed between the front body 20 and the protective nut 26. The micro gap 27 of the base body 19 communicates with the outside through the base body 1.
The base body 19 and the support body 28 attached to the rear part of the body 9 and supporting the body 3 communicate with the outside. Reference numeral 29 is a paint pipe that supplies paint such as water-based paint to the rotary cup 1, and the paint is supplied from the tip 29a to the rear cylinder body 9 of the rotary cup 1.
The paint pipe 29 is made to flow down onto the inner peripheral surface.
As shown in FIG. 2, the rear part of the holder is connected to a paint supply section 30 consisting of a paint pump, a paint tank, etc., and paint is continuously supplied.

Note that when a highly conductive paint such as a water-based paint is used as the paint, the paint supply section 30 is subjected to a high voltage insulation treatment. Further, 31 is a compressed air supply pipe, which is connected to the rear end of the air passage 12 of the rotating shaft 2 via a relay passage 32 in the support body 28, and this compressed air supply pipe 31 is connected to the nozzle of the drive chamber 4. It is connected to a high pressure air generation source 39 together with an air motor pipe 33 connected to the air motor pipe 24 . 34 is a high voltage generation source that applies high voltage between the object to be painted 35 and the rotary turntable 1 or the main body 3;
36 is an insulating arm, and 37 is an arm support portion.

Next, the operation of the device of the present invention will be explained.

Paint is supplied from the paint supply section 30 to the paint pipe 29 via the paint tube 41, and the tip 29a of the paint pipe 29
The paint is allowed to flow down continuously in small amounts from the opening onto the rear inner circumferential surface of the rear cylinder body 9 of the rotary cup 1. On the other hand, compressed air supplied from the high-pressure air generation source 39 via the air motor pipe 33 is blown into the drive chamber 4 from the nozzle 24.
When the blades 5 receive this air pressure, the rotating shaft 2 is rotated to 1
It rotates at a high speed of 000 to 60000 rpm. As this rotating shaft 2 is rotated by the action of an air motor using blades 5, the rotating turnip 1 is also rotated at high speed. Here, the paint that has flowed down onto the inner peripheral surface of the rear cylinder 9 is subjected to centrifugal force due to the high speed rotation of the rear cylinder 9, and spreads on the rear inner peripheral surface of the rear cylinder 9. It moves in the direction of the tip along the taper of the surface, becoming a thin film, and finally the tunnel part 17.
The paint is supplied into the paint dispersion cup 15 through the centrifugal force from the paint outlets 16 formed at equal intervals on the outer circumference of the paint dispersion cup 15, and is then radiated out onto the rear inner circumference of the front cylinder body 10. The same amount is supplied to the entire circumference. Further, on the inner circumferential surface of the front cylinder 10, it is supplied in the form of a thin film in the direction of the knife edge portion 18 along the taper while expanding in the inner circumferential direction. The paint thus formed into a thin film is supplied to the knife edge section 18. If this paint is a normal oil-based paint, it can be easily charged due to its low conductivity. is electrostatically atomized by the action of a high electric field caused by an applied high voltage,
Further, due to the action of this electric field, the atomized paint starts flying in the direction of the object to be painted 35 which is kept at the ground potential. On the other hand, if the above-mentioned paint is a conductive paint such as a water-based paint, the width of the cylinder gap 38 between the outer peripheral surface of the front cylinder 10 and the inner peripheral surface of the tip of the outer cylinder 11 is narrowed to 2wn or less. At the same time, the position of the cylindrical body gap 38 is adjusted to the rear 10W of the knife edge portion 18.
f1 or less, and connect the compressed air supply pipe 31, the relay path 32, and the air passage 12 of the rotating shaft 2 from the high-pressure air generation source 39 to the
The compressed air supplied to the annular air chamber 14 through the communication hole 13 of the rear cylinder body 9 is blown out from the cylinder gap 38 to increase the flow velocity of the annular cylindrical dinit air flow spirally flowing from the cylinder gap 38. The wind pressure of the dinit airflow ejected from the cylinder gap 38 atomizes the water-based paint supplied to the knife edge portion 18 and gives an initial velocity to the atomized water-based paint. Object to be painted with paint 3
Makes it fly in five directions. The atomized paint that is atomized by the action of the high electric field or the synergistic action of the high electric field and the dinit airflow as described above is given an initial velocity by the dinit airflow, and is accelerated by the action of the high electric field, and the object to be coated is 35
However, at the same time, the atomized paint is surrounded by the annular cylindrical dinit airflow flowing in a spiral shape, preventing the atomized paint from scattering in unnecessary directions, and reducing the atomization. The flying direction of the paint can be made uniform in the direction of the object to be painted. By the way, when the paint is a normal oil-based paint, electrostatic atomization can be easily performed, so the role of the annular and cylindrical dinit air flow that flows in a spiral shape is to further atomize the atomized paint and to atomize it. It is only used to control the spread of the paint within a certain range, and there is no need to form a particularly high-speed dinit airflow; rather, the outer cylinder body 11 is moved backward relative to the front cylinder body 10 to form a cylinder that becomes a jet outlet for the dinit airflow. It would be better to widen the width of the body gap 38 and increase the thickness of the annular dinit airflow to appropriately control the spread of the flying atomized paint. In addition, when rotating the blade 5 by supplying compressed air from the nozzle 24, the drive chamber 4
The interior becomes pressurized, and this pressurized state may cause the grease in the bearing 6 that supports the rotating shaft 2 to flow out to the side opposite to the drive chamber 4, reducing the sliding properties of the bearing 6. However, an air retention chamber 7 formed on the opposite side of the drive chamber 4 of the bearing 6 is communicated with the drive chamber 4 through a communication passage 8, and the pressure in the drive chamber 4 and the pressure in the air retention chamber 7 are balanced. Bearing 6
Balance the left and right air of the air storage chamber 7 like this.
By achieving air balance by the air balance means constituted by the communication path 8 and the communication passage 8, the grease in the bearing 6 is prevented from flowing out due to the pressurized state of the drive chamber 4. Further, the air in the drive chamber 4 is discharged from the exhaust port 25, but some of the air escapes from the air retention chamber 7 to the outside through the minute gap 27. The rotating shaft 2 and main body 3 are cooled by the air passing through the small gap 27 between the rotating shaft 2 and the main body 3, and the expansion of the rotating shaft 2 due to frictional heat due to rotation can be suppressed, and high-speed rotation can be maintained using the air of the air motor. In addition, even if dust or the like enters from the nozzle 24, the air passing through the minute gap 27 blows the dust away and removes it, so there is no fear that the dust will become clogged and impede the rotation of the rotating shaft 2. It is something. As described above, the first invention of the present invention introduces air into the drive chamber, blows the air against the blades in the drive chamber, and rotates the rotating shaft of the rotating cup of the electrostatic coating device as the blades rotate. In such an electrostatic coating device, there is a drive chamber in which air is introduced to drive the blades of the rotating shaft, and an air retention chamber between the rotating shaft and the main body at a position opposite to the bearing that supports the rotating shaft. , and a communication passage is provided between the drive chamber and the air retention chamber, so that the pressure in the air retention chamber and the pressure in the drive chamber can be balanced by the communication passage, and the bearing When balancing the left and right air, the air in the drive chamber is introduced into the air storage chamber so that the air in the drive chamber can be used as is to balance the air. Air balance for preventing outflow can be obtained with a simple configuration.

Furthermore, in the second invention, since a minute gap is formed between the rotating shaft and the main body so that the air retention chamber communicates with the outside, a part of the air is transferred from the air retention chamber to the minute gap. The air that passes through the small gap between the rotating shaft and the main body cools the rotating shaft and prevents the rotating shaft from expanding due to frictional heat caused by rotation. Not only can high-speed rotation be maintained, but even if dirt does get in, the air that passes through the tiny gap will blow it out and remove it, so there is no risk of dirt clogging and interfering with the rotation of the rotating shaft. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, and FIG. 2 is a reduced front view showing the entire same. 1 is a rotating cup, 2 is a rotating shaft, 3 is a main body, 4 is a drive chamber,
5 is a blade, 6 is a bearing, 7 is an air retention chamber, and 8 is a communication passage.

Claims (1)

[Scope of Claims] 1. A rotating shaft equipped with a rotary cup for electrostatic atomization of paint at one end is rotatably inserted into the main body, and rotates under air pressure in a drive chamber of the main body into which air is introduced. A blade for rotationally driving the shaft is provided on the rotating shaft, a bearing for supporting the rotating shaft is interposed between the rotating shaft and the main body, and a blade is provided between the rotating shaft and the main body at a position opposite to the drive chamber of the bearing. Forms an air storage chamber,
An electrostatic coating device characterized by having a communication path communicating between a drive chamber and an air retention chamber. 2. In the electrostatic coating device according to claim 1,
An air passage is provided in the rotating shaft in the axial direction to supply air to be injected from the outer periphery of the tip of the rotating cup. 3 A rotary shaft equipped with a rotary cup for electrostatic atomization of paint at one end is rotatably inserted into the main body, and a blade receives air pressure in the drive chamber of the main body into which air is introduced to drive the rotary shaft to rotate. is provided on the rotating shaft, and a bearing for pivotally supporting the rotating shaft is interposed between the rotating shaft and the main body, and an air communicating with the driving chamber is provided between the rotating shaft and the main body at a position opposite to the drive chamber of the bearing. An electrostatic coating device characterized by forming a retention chamber and forming a minute gap between a rotating shaft and a main body so that the air retention chamber communicates with the outside. 4 In the electrostatic coating device according to claim 3,
An air passage is provided in the rotating shaft in the axial direction to supply air to be injected from the outer periphery of the tip of the rotating cup.