JPH046831Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention applies a high voltage between the rotating atomizing head of a paint sprayer and the object to be coated, and charges the liquid paint supplied to the rotating atomizing head. A rotating atomizer that is atomized and released from the periphery of a rotating atomizing head, and is charged by electrostatic force generated based on the potential difference between the rotating atomizing head and the object to be coated, and the atomized paint particles are applied to the surface of the object to be coated. This relates to an electrostatic coating machine, and more specifically, as a rotating atomizing head,
A hollow truncated conical bell rim is coaxially connected and fixed to the outer peripheral edge of the disc-shaped projection of the bell hub, and a plurality of paint passages are provided at the joint portion to respectively communicate the rear chamber and the front chamber of the bell rim internal cavity. The rotary atomizer uses a bell-shaped rotary atomizer head to which a high voltage is applied, supplies liquid paint to the rear chamber of the bell rim in the rotary atomizer head, and releases charged atomized paint particles from the outer periphery of the front end of the bell rim. This relates to electric coating machines.

BACKGROUND ART The inner peripheral wall of the intermediate portion of a hollow truncated conical bell rim is circumferentially connected and fixed to the outer peripheral edge of a disc-shaped projection of a bell hub, and the interior of the bell rim defined by the disc-shaped projection of the bell hub is attached to the joint. A bell-shaped rotating atomizing head, which has a plurality of paint passages that communicate the rear and front chambers of the empty spaces, is attached and fixed to the front end of the rotating shaft of the motor that drives the rotation of the atomizing head. A high voltage is applied to the head, liquid paint is supplied into the rear chamber of the bell rim by a paint supply nozzle whose tip is inserted into the rear chamber of the bell rim through a circular opening at the rear end of the bell rim, and the liquid paint is atomized from the periphery of the front end of the bell rim. Rotating bell-type rotary atomizing electrostatic coating machines that emit paint particles have been widely used for a long time in various coating applications.

However, in recent years, with the aim of improving coating quality and coating efficiency by increasing the atomization of atomized paint particles, and downsizing atomizers, motors for driving the atomization head are being rotated at tens of thousands of revolutions per minute or more. It has become common practice to rotate a rotary atomizer head at high speeds using an air motor with a rotation speed as high as By selectively supplying liquid paint of a desired color through a paint color changing device, it is also possible to perform color changing painting using the same painting machine, which is a common method for painting the exterior of automobile bodies, for example. This has led to a number of problems in conventional rotary bell-type rotary atomizing electrostatic sprayers.

Specifically, for example, when liquid paint is injected and supplied from the paint supply nozzle to the rear chamber of the bell rim of a rotary atomizing head that rotates at a high speed of 10,000 revolutions per minute or more, the liquid paint on the wall surface of the rear chamber Paint splashes occur due to poor adhesion, and the relatively large scattered paint particles generated by this splash adhere to and accumulate on the outer surface of the paint supply nozzle, or escape from the rear chamber through the circular opening at the rear end of the bell rim. If it flies out, the following inconvenient situations may occur. In other words, it is difficult to remove the paint that has adhered or accumulated on the outer surface of the paint supply nozzle by spraying a cleaning liquid through the paint supply nozzle, which is normally done when changing the paint color. After the paint color was changed, the paint peeled off from the outer surface of the nozzle and fell into the rear chamber of the bell rim, causing color mixing of the paint, and large particles of scattered paint flew outward through the circular opening at the rear end of the bell rim. The particles are directly transferred to the object to be coated by electrostatic force acting between the rotating atomizer head and the object to be coated, or by air for shaping the atomized paint pattern that is generally sprayed around the outer periphery of the rotating atomizer head. The paint may adhere to the surface of the object and cause coating defects, or it may adhere to or accumulate on the front end surface of the air motor housing and peel off due to vibrations of the air motor, and the electrostatic force may cause the paint to form so-called spit on the surface of the object to be coated. This caused paint to adhere to the surface of the paint, causing paint defects and color mixing.

Furthermore, in order to prevent splashed paint particles from flying outward from the circular opening at the rear end of the bell rim, it is conventional to attach a closing member to the front end portion of the air motor housing to close the circular opening at the rear end of the bell rim. However, since it is difficult to clean the front end wall surface of the conventional closing member with a cleaning solution, the paint that has adhered or accumulated on the front end wall surface remains as it is without being removed. This, along with the paint deposited on the outer surface of the paint supply nozzle, caused color mixing in the paint.

Problems to be Solved by the Invention It is an object of the present invention to provide a rotary bell-type rotary atomizing electrostatic coating machine with a bell-type rotary atomizing head that is rotationally driven at high speed by an air motor, in which a paint supply nozzle is provided. Injected into the rear chamber of the bell rim of the rotating atomizing head,
Prevents scattered paint particles generated by the splashing of the supplied liquid paint from flying outward through the circular opening at the rear end of the bell rim, and also blocks the outer surface of the paint supply nozzle and the circular opening at the rear end of the bell rim. Rotating bell type that can easily wash and remove paint that has adhered or accumulated on the front end wall of the closing member, and eliminates the risk of paint defects or paint color mixing caused by scattered paint particles generated by rebounding. An object of the present invention is to provide a rotary atomizing electrostatic coating machine.

Means for Solving the Problems The rotary bell type rotary atomizing electrostatic coating machine of the present invention has a bell type rotary atomizing head which is different from the rotary bell type rotary atomizing electrostatic coating machine having the well-known structure described above. The rear chamber of the bell rim is provided with a cylindrical circumferential wall extending forward from its rear end, and an annular rear wall projecting inward from the front end of the inner circumferential wall and having an angle substantially perpendicular to or close to the center axis of the bell rim. An annular jetty portion is provided, and the closing member fitted and fixed to the front end portion of the air motor housing is parallel to the cylindrical inner circumferential wall of the bell rim rear chamber and the annular rear wall of the annular jetty portion with a small gap between them. A hollow cylindrical front protrusion that loosely fits around the outer periphery of the rear end portion of the bell hub has a cylindrical outer circumferential wall and an annular front end wall, and the front protrusion is inserted into the bell rim rear chamber through a circular opening at the rear end of the bell rim. The circular opening at the rear end of the bell rim is fitted into the circular opening at the rear end of the bell rim. A large number of cleaning liquid discharge ports are opened in a direction approximately parallel to the center axis of the bell rim at approximately equal intervals along a circle centered on the axis, and the base of the paint supply nozzle is hollow by being located radially inward from these cleaning liquid discharge ports. Attached to the cylindrical front protrusion, the nozzle portion of the paint supply nozzle exposed forward from the front end of the front protrusion is rotated along approximately one-fourth of the circumference of the outer peripheral wall of the hollow cylindrical rear end portion of the bell hub. The hollow cylindrical front projection is curved in an arc in the same direction as the rotational direction of the head and projected diagonally forward, with its tip opening toward the vicinity of the connecting portion between the bell rim and the disc-shaped projection of the bell hub. In the portion of the cylindrical outer peripheral wall of the rear chamber facing the cylindrical inner peripheral wall of the bell rim rear chamber, a large number of air jet ports are opened obliquely forward and outward at approximately equal intervals along the circumference of the outer peripheral wall, and a closing member is provided. The main body part includes a cleaning liquid passage for supplying cleaning liquid to each of the cleaning liquid discharge ports, an air passage for supplying pressurized air to each of the air jet ports, and a liquid paint and cleaning liquid passage for selectively supplying liquid paint and cleaning liquid to the paint supply nozzle. A distinctive feature of the structure is that paint and cleaning liquid passages are provided for switching and supplying the paint and the cleaning liquid to each other.

Function The function of the rotary bell type rotary atomizing electrostatic coating machine of the present invention having the above-mentioned special configuration will be explained as follows.

First, during normal painting work, a DC high voltage of, for example, -70 to 90 KV is applied to the bell-shaped rotating atomizing head through a high voltage cable extending from a suitable DC high voltage generator, and the rotating atomizing head is turned on by an air motor. While driving and rotating at a high speed of, for example, tens of thousands of revolutions per minute, the paint-cleaning liquid passage is connected to a paint supply source, and paint is injected and supplied from the paint supply nozzle into the rear chamber of the bell rim, and then the normal method is carried out. Therefore, the object to be coated is electrostatically coated, and at this time pressurized air of approximately 2 kg/cm ² is applied from each air outlet provided on the cylindrical outer peripheral wall of the hollow cylindrical front protrusion of the closing member. is injected into each narrow gap between the cylindrical inner circumferential wall of the bell rim rear chamber and the annular rear wall of the annular jetty, and the cylindrical outer circumferential wall and annular front end wall of the hollow cylindrical front end portion of the closing member. The exhaust air of the air motor is caused to flow into the rear chamber of the bell rim through a narrow gap between the inner circumferential wall of the hollow cylindrical front end portion of the closing member and the outer circumferential wall of the rear end portion of the bell hub. to prevent paint from entering these gaps. Therefore, the rear end of the rear chamber of the bell rim of the rotary atomizing head is effectively sealed by the air flow flowing into the rear chamber of the bell rim through the closing member and the above-mentioned gaps, and the flying paint particles generated by the splashing of the paint are prevented. It is completely prevented from flying outward from the rear chamber of the bell rim, so there is no risk of paint defects caused by scattered paint particles, and there is no risk of paint defects occurring on the outer surface of the paint supply nozzle or the front end of the blocking member during painting operations. Even if paint adheres or accumulates on the wall surface, this paint will not form a so-called spit on the surface of the object to be painted and cause painting defects. Furthermore, when changing the color of the paint, the outer surface of the paint supply nozzle and Paint that adheres and accumulates on the front end wall of the closing member is
Since it is completely cleaned and removed as explained below, there is no risk of color mixing in the paint.

Next, I will explain the cleaning work when changing the paint color and after finishing the painting work.
The air motor is operated to rotate the bell-shaped rotary atomizing head, preferably at a rotation speed slightly slower than that during painting work, and each air outlet is provided in the cylindrical outer peripheral wall of the intermediate cylindrical front protrusion of the closing member. While blowing out pressurized air at a pressure of, for example, about 4 kg/cm ² , the paint-cleaning liquid passage is switched and connected to the cleaning liquid supply source, and the cleaning liquid is injected into the rear chamber of the bell rim through the paint supply nozzle, and the cleaning liquid is further injected into the hollow cylinder of the closing member. The cleaning liquid is also discharged from each cleaning liquid discharge port provided in the annular front end wall of the front end portion of the shape. When the air is injected, it collides with the wall surface near the connecting part between the disc-shaped protrusion of the bell hub and the bell rim, and is reflected. At the same time, the air is supplied from each air injection port to the cylindrical inner circumferential wall of the rear chamber of the bell rim and the circle of the annular jetty. Pressurized air flows in through the gap between the annular rear wall, the cylindrical outer peripheral wall of the hollow cylindrical front end portion of the closing member, and the annular front end wall, and the outer peripheral wall of the rear end portion of the bell rim and the hollow cylindrical front end portion of the closing member. The air flowing in through the gap with the inner peripheral wall of the bell rim is stirred by the exhaust air of the motor and flows violently inside the rear chamber of the bell rim, cleaning the rear interior wall surface and the outer wall surface of the tip of the paint supply nozzle. The adhering and accumulated paint is completely removed, and the cleaning liquid discharged from each cleaning liquid outlet is jetted out from each air outlet mentioned above to the wall of the rear chamber of the bell rim and the wall of the hollow cylindrical front end of the closing member. The pressurized air flowing in through the gap between the hollow cylindrical front end portion causes a turbulent flow along the wall surface of the annular front end wall of the hollow cylindrical front end portion and the outer wall surface of the tip of the paint supply nozzle protruding forward from the front end wall. The water is swept away to thoroughly clean these wall surfaces and completely remove the paint that has adhered or accumulated on the walls. The cleaning liquid that has cleaned the inside of the rear chamber of the bell rim in this way is transferred to the front chamber of the bell rim through each paint passage by the centrifugal force based on the high-speed rotation of the rotating atomizing head, and spreads outward toward the front end of the bell rim. The cleaning work is completed by being swept along the peripheral wall of the chamber, cleaning the wall surface, completely removing any remaining paint that adheres to the wall surface, and then being atomized and discharged from the front edge of the front chamber of the bell rim. Note that the cleaning with the cleaning liquid sprayed from the paint supply nozzle and the cleaning with the cleaning liquid discharged from each cleaning liquid discharge port, which are performed during the above-mentioned cleaning operation, are performed simultaneously and consecutively in parallel with each other. Alternatively, it may be repeated several times intermittently while switching alternately. If desired, the continuous jetting of cleaning fluid from the paint supply nozzle may be replaced by alternating jets of cleaning fluid and pressurized air, and the continuous jetting of cleaning fluid from each cleaning fluid outlet may be replaced by cleaning fluid and pressurized air. It is also possible to perform alternate discharge with air.

By the way, during the painting process, the liquid paint supplied to the rear chamber of the bell rim by the paint supply nozzle and transferred to the front chamber of the bell rim through each paint passage is all absorbed by the centrifugal force caused by the high-speed rotation of the bell-shaped rotating atomizing head. Since the paint is guided along the truncated conical inner peripheral wall of the bell rim front chamber to the front edge of the bell rim front chamber, no paint adheres to the front wall of the disc-shaped protrusion of the bell hub.
Therefore, it is actually unnecessary to clean this wall surface during cleaning operations.

Example Hereinafter, an example of a rotary bell type rotary atomizing electrostatic coating machine in which the present invention is implemented will be described with reference to the attached drawings. As is clear from the side view shown in FIG.
The inner circumferential wall of the axially intermediate portion of the hollow truncated conical bell rim 3 is joined and fixed, for example, by welding, and the internal space of the bell rim 3 is connected to the rear chamber 4 and the front chamber 5 by the disc-shaped projection 2 of the bell hub 1. It is divided into two parts, Bell Hub 1.
A plurality of paint passages 6 are provided with substantially equal gaps in the circumferential direction at the joint portion between the bell rim 3 and the peripheral edge of the disc-shaped protrusion 2, and each of these paint passages connects the rear chamber 4 of the bell rim 3. The substantially hollow cylindrical rear end portion 8 of the bell hub 1 of the bell-shaped rotary atomizing head 7 which communicates with the front chamber 5 and the front chamber 5 is connected to the front end portion of the rotating shaft 10 of a suitable air motor 9 for driving the atomizing head rotation. The housing 11 of the air motor 9 is fitted and fixed through a suitable support member, and the nozzle portion of the supported paint supply nozzle 12 is made to protrude into the rear chamber 4 of the bell rim, and the rear end of the paint gun is fixed. A high-voltage cable (not shown) introduced into the rotary shaft 10 of the air motor 9 and a rotating atomizing head fixed thereto via any suitable electrical contact or narrow discharge gap (not shown) 7 for example -70-90KV
Although it has a conventionally well-known structure in that it applies a high DC voltage, it has a special structure that is completely different from conventional coating machines of this type in the following points.

That is, the bell rim rear chamber 4 of the bell-shaped rotary atomizing head 7 includes a cylindrical inner circumferential wall 13 extending forward from its rear end, and a cylindrical inner circumferential wall 13 protruding radially inward from the front end of the cylindrical inner circumferential wall. An annular projection part 15 is provided with an annular rear wall 14 having an angle substantially perpendicular to or close to the central axis of the bell rim 3, and is attached to the front end portion of the housing 11 of the air motor 9 to form a circular rear end of the bell rim 3. A closing member 17 is provided to close the opening 16, and the cylindrical inner circumferential wall 13 of the bell rim rear chamber 4 and the annular jetty are attached to the front wall surface of the closing member 17 in a state where the closing member is attached and fixed to the housing of the air motor. 15
The outer periphery of the rear end portion 8 of the bell hub 1 has a cylindrical outer peripheral wall 19 and an annular front end wall 20 that are parallel to each other with a narrow gap 18 of, for example, about 1.5 to 2 mm separated from the annular rear wall 14 of the bell hub 1. A hollow cylindrical front protrusion 22 that fits loosely across a narrow gap 21 is formed, and the annular front end wall 20 of this front protrusion 22 has a ridge line of an annular protrusion 15 provided in the bell rim rear chamber 4. That is, the annular rear wall 14
A large number of cleaning liquid discharge ports 23 are arranged at approximately equal intervals along a circle centered on the central axis of the bell rim 3, with the axes thereof being parallel to the central axis of the bell rim 3. The paint supply nozzle 12 is closed and opened, and the paint supply nozzle 12 is located radially inside of these cleaning liquid discharge ports.
The base of the paint supply nozzle 1 is installed with its axis parallel to the center axis of the bell rim 3.
2, that is, the nozzle portion exposed forward from the front end wall 20 of the front protrusion 22 of the closing member 17 and inserted into the bell rim rear chamber 4, is inserted into the bell hub 1 as shown by the broken line in the drawing. The approximately hollow cylindrical rear end portion 8 of the rear end portion 8 is curved in an arc shape and protrudes obliquely forward in the same direction as the rotational direction of the rotary atomizing head. The tip part is opened toward the vicinity of the connecting part between the bell rim 3 and the disc-shaped projection 2 of the bell hub 3, and the cylindrical outer peripheral wall 19 of the front projection part 22 faces the cylindrical inner peripheral wall 13 of the bell rim rear chamber 4. A large number of air jet ports 24 are opened at approximately equal intervals along the circumference of the outer peripheral wall 19 with their axes tilted forward and outward, and the main body portion 25 of the closing member 17 is A cleaning liquid passage 26 communicates with each of the cleaning liquid discharge ports 23 provided on the front protrusion 22 to supply cleaning liquid to these discharge ports, and a cleaning liquid passage 26 communicates with each of the air jet ports 24 to supply pressurized air to these jet ports. An air passage 27 for supplying liquid paint and a paint-cleaning liquid passage 28 that communicates with the paint supply nozzle 12 and selectively switches and supplies liquid paint and cleaning liquid to the nozzle are provided. The hollow cylindrical front protrusion 22 of the closing member 17 is connected to the circular opening 1 at the rear end of the bell rim 3.
6 is loosely fitted into the bell rim rear chamber 4 to close the rear end circular opening 16, and the main body portion 25 of the closing member 17 is fitted and fixed to the front end portion of the housing 21 of the air motor 9.

Although not shown in the illustrated embodiment, if desired, atomization by the rotating bell-shaped atomizing head 7 may be carried out surrounding the outside of the bell-shaped rotating atomizing head 7, according to well-known techniques. A suitable shaping air ejection annular member may be attached to the front end outer portion of the body portion 25 of the closure member 17 for generating a pattern shaping air flow to adjust the pattern of the charged atomized paint particles to be ejected. can.

Effects of the Invention According to the rotating bell type rotary atomizing electrostatic coating machine of the present invention having the above-mentioned configuration, the following useful and outstanding effects can be obtained.

(1) During painting work, the liquid paint that is injected and supplied from the paint supply nozzle into the rear chamber of the bell rim of the bell-shaped rotary atomizer head, which rotates at a high rotational speed of tens of thousands of revolutions per minute, may be sprayed onto the rear interior wall. Even if relatively large sprayed paint particles are generated due to rebound due to poor adaptation to the rear chamber, the rear end of the rear chamber is connected to the hollow cylindrical front surface of the closing member that is loosely fitted into the rear chamber through the circular opening at the rear end of the bell rim. The narrow gap between the rear interior wall surface and the outer wall surface of the front projection section is sealed by the air flow flowing into the rear interior chamber through this gap. It is completely prevented from scattering or escaping from the rear end to the outside, so there is no risk that the scattered paint particles will adhere to the surface of the object to be coated and cause coating defects, making it possible to obtain extremely high-quality coatings. can.

(2) When cleaning at the end of painting or when changing paint colors, first clean the paint-cleaning liquid passage and the inside of the paint supply nozzle with the cleaning liquid supplied through the paint supply nozzle, and then clean the rear part of the bell rim. The action of pressurized air supplied through each air outlet by cleaning and removing paint that has adhered or accumulated on the interior wall surface and the outer wall surface at the tip of the paint supply nozzle, and by the cleaning fluid supplied through each cleaning fluid outlet. The paint that has adhered to and accumulated on the annular front end wall surface of the front protrusion of the closing member and the outer wall surface of the exposed nozzle portion of the paint supply nozzle is cleaned and removed using the cleaning solution that has finished cleaning the rear chamber of the bell rim. Therefore, by cleaning the inner peripheral wall surface of each paint passage and the front chamber of the bell rim using centrifugal force based on the high-speed rotation of the rotary atomizing head, residual paint in the paint supply path, nozzle, and rotary atomizing head can be removed. Since it is completely removed, there is no risk of paint color mixing.

[Brief explanation of drawings]

The accompanying drawing is a side view showing a main part of an embodiment of the rotary bell type rotary atomizing electrostatic coating machine of the present invention, with the bell type rotary atomizing head and closing member cut away. In the figure, 1 is a bell hub, 2 is a disc-like projection of the bell hub, 3 is a bell rim, 4 is a rear chamber of the bell rim, 5 is a front chamber of the bell rim, 6 is a paint passage, 7 is a bell-shaped rotating atomizing head, and 8 is a bell-shaped rotary atomizing head. Rear end of bell hub, 9
is the air motor, 10 is the rotating shaft of the air motor, 11
12 is the housing of the air motor, 12 is the paint supply nozzle, 13 is the cylindrical inner wall of the rear chamber, 14 is the annular rear wall of the annular jetty, 15 is the annular jetty, 16 is a circular opening at the rear end of the bell rim, and 17 is the annular rear wall of the annular jetty. Closing member, 18,
21 is a gap, 19 is a cylindrical outer peripheral wall of the front protrusion,
20 is an annular front end wall of the front protrusion, 22 is the front protrusion of the closing member, 23 is a cleaning liquid outlet, 24 is an air outlet, 25 is a main body portion of the closing member, 26 is a cleaning liquid passage, 27 is an air passage, Reference numeral 28 indicates a paint-cleaning liquid passage.

Claims (1)

[Scope of utility model registration request] A hollow truncated conical bell rim is coaxially joined and fixed to the outer peripheral edge of the disc-shaped projection of the bell hub, and a rear chamber and a front chamber of the bell rim internal cavity partitioned by the disc-shaped projection are formed at the joint part, respectively. A bell-shaped rotating atomizing head with a plurality of communicating paint passages provided at approximately equal intervals is attached and fixed to the front end of the rotating shaft of an air motor for driving the rotation of the atomizing head, and a high voltage is applied to the rotating atomizing head. The tip of the paint supply nozzle is inserted into the rear chamber of the bell rim through a circular opening at the rear end of the bell rim. The liquid paint supplied to the rear chamber is transferred to the front chamber through each paint passage, and the liquid paint is charged by the high voltage applied to the rotary atomizer head and the high speed rotation of the rotary atomizer head, and the liquid paint is charged at the front end of the bell rim. It is a rotating bell-type rotary atomizing coating device that emits atomized water from the periphery, and the rear chamber of the bell rim of the rotating atomizing head has a cylindrical inner circumferential wall extending forward from its rear end, and a cylindrical inner circumferential wall extending from the front end of the cylindrical inner circumferential wall. an annular projection having an annular rear wall protruding radially inward and having an angle substantially perpendicular, perpendicular, or close to the central axis of the bell rim, and in the installed state, the bell rim rear chamber A hollow cylinder that has a cylindrical outer peripheral wall and an annular front end wall that are parallel to the cylindrical inner peripheral wall and the annular rear wall of the annular jetty part with a small gap therebetween, and that fits loosely into the outer periphery of the rear end portion of the bell hub. fitting a main body portion of a closure member having a front protrusion in the shape of a front end into a front end portion of a housing of an air motor with the hollow cylindrical front protrusion being fitted into a rear chamber of the bell rim through a circular opening at the rear end of the bell rim; The bell rim center axis is fixed to the annular front end wall of the hollow cylindrical front protrusion of the closing member slightly radially inward from the inner peripheral edge of the annular rear wall of the annular projection provided in the bell rim rear chamber. A large number of cleaning liquid discharge ports are opened at approximately equal intervals along the center circle in a direction approximately parallel to the center axis of the bell rim, and the base of the paint supply nozzle is positioned radially inward from these cleaning liquid discharge ports to form a hollow cylindrical front surface. At the same time as attaching it to the protruding part, the nozzle part exposed forward from the front end surface of the front protruding part of the paint supply nozzle is attached to the rotary atomizing head along about a quarter of the circumference of the outer peripheral wall of the hollow cylindrical rear end part of the bell hub. The cylinder of the hollow cylindrical front protrusion is made to protrude diagonally forward while being curved in an arc shape in the same direction as the rotation direction, and its tip is opened toward the vicinity of the connecting portion between the bell rim and the disc-shaped protrusion of the bell hub. In a portion of the shaped outer peripheral wall facing the cylindrical inner peripheral wall of the bell rim rear chamber, a large number of air jet ports are opened obliquely forward and outward at approximately equal intervals along the circumference of the outer peripheral wall, and the main body of the closing member is The portion includes a cleaning liquid passage for supplying cleaning liquid to each of the cleaning liquid discharge ports, an air passage for supplying pressurized air to each of the air jet ports, and a liquid paint and cleaning liquid passage for selectively supplying liquid paint and cleaning liquid to the paint supply nozzle. A rotary bell-type rotary atomizing electrostatic coating machine characterized by having separate paint and cleaning liquid passages for switching supply.