JP3433080B2 - Rotary atomizing head type coating equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary atomizing head type coating apparatus suitable for coating an object to be coated while changing colors.

[0002]

2. Description of the Related Art Generally, a coating apparatus using a rotary atomizing head has a cover formed in a tubular shape, an air motor provided in the cover, and an air motor which is inserted in the axial direction of the air motor and rotated by the air motor. A rotary shaft, a rotary atomizing head attached to the rotary shaft and rotating at a high speed by the rotary shaft, the rotary shaft extending axially in the rotary shaft, and extending in the rotary atomizing head. It is generally composed of a feed tube that discharges paint or thinner as a solvent from its tip.

Further, the rotary atomizing head is provided at a bell cup formed in a bell shape or a cup shape and located on the inner peripheral side of the bell cup, and is provided between the bell cup and the feed tube. A hub member that defines a paint reservoir that stores the discharged paint, and a paint or thinner that is provided on the outer peripheral side of the hub member and that is discharged from the feed tube is applied from the paint reservoir to the tip side of the inner peripheral surface of the bell cup. A plurality of paint outflow holes that flow out to the formed discharge end and a plurality of solvent outflows that are provided in the central portion of the hub member and allow thinner discharged from the feed tube to flow out from the paint reservoir to the front surface of the hub member. And a hole.

The feed tube is connected to a color changing valve device for supplying paint, air and thinner through a paint pipe. Further, the coating device is connected to a high voltage generator, a negative high voltage is applied, and electrostatic coating is performed.

When coating is performed by the conventional rotary atomizing head type coating apparatus having such a structure, first, compressed air is supplied to the air motor to rotate the rotary atomizing head together with the rotary shaft at a high speed. Then, the paint is discharged from the feed tube toward the paint reservoir in the rotary atomizing head. As a result, the paint flows along the inner peripheral surface of the bell cup, and after being thinned, is discharged as charged paint particles from the discharge edge on the tip side. At this time, since an electrostatic field is formed between the coating device and the object to be coated, the charged paint particles discharged from the discharge edge of the rotary atomizing head are along the lines of electric force. And is applied to the object to be coated.

Further, when the paint is changed to the next color paint, air thinner is supplied from the color change valve device into the rotary atomizing head to adhere to the liquid contact surface of the rotary atomizing head. Wash the previous color paint. After that, the next color paint is supplied to the paint supply path to prepare for the next color painting operation.

However, at the time of supplying the above-mentioned next color paint,
The next color paint may adhere to the front surface of the hub member of the rotary atomizing head and the outer peripheral surface of the bell cup. Further, even when the painting work is temporarily stopped due to a trouble in the painting line, a break during lunch break, or the like, the paint attached to the rotary atomizing head may be solidified. Further, when the same color paint is continuously applied for a long time, the paint may adhere to and accumulate on the rotary atomizing head.

In such a case, the paint adhered to the rotary atomizing head is solidified and peels off at the time of coating to cause a coating failure. Therefore, the paint adhered to the liquid contact surface of the rotary atomizing head is washed. There is a need.

Therefore, in order to wash the paint adhering to the rotary atomizing head, the rotary shaft and the rotary atomizing head are rotated by an air motor, and the rotation is carried out from the feed tube separately from the air thinner from the color changing valve device. The thinner is discharged into the paint reservoir of the atomizing head. As a result, a part of the thinner is supplied from the paint reservoir through each paint outflow hole to the discharge edge or the like, and cleans the paint adhered to the discharge edge or the like. Further, some thinners are supplied to the front surface of the hub member through the solvent outflow holes to wash the paint adhering to the front surface of the hub member.

By the way, in such a conventional coating apparatus, a high voltage is applied to the paint particles discharged from the discharge edge of the bell cup during coating, and most of the charged paint particles are grounded. It flies along the electrostatic field formed between the object to be coated connected to the side and coats it. However, some paint particles may flow backward so as to wrap around behind the bell cup and adhere to the tip end side of the outer peripheral surface of the bell cup.

That is, when the rotary atomizing head rotates at high speed, a negative pressure region is generated on the front surface of the bell cup due to this high speed rotation.
An air pumping phenomenon occurs in which air is sucked into this negative pressure region, and the paint particles flow backward toward the rear of the bell cup.

Further, in order to form the spray pattern of the paint sprayed from the rotary atomizing head in accordance with the coating conditions of the object to be coated, a shaping air jet port is provided at the tip side of the cover, and the shaping is performed. Shaping air is ejected from the air ejection port toward the outer peripheral side of the rotary atomizing head.
Therefore, a negative pressure is partially generated on the outer peripheral side of the bell cup due to the jet flow by the shaping air, and the paint particles flow backward toward the rear of the bell cup.

In this way, when some paint particles flow backward and adhere to the tip of the outer peripheral surface of the bell cup, the adhered paint solidifies. Therefore, depending on the coating conditions, this solidified coating material may peel off from the bell cup and adhere to the surface of the object to be coated as a coating material piece, which may deteriorate the coating quality.

Further, the conventional coating apparatus can clean the discharge edge of the bell cup and the front surface of the hub member by supplying thinner from the feed tube toward the inner peripheral side of the bell cup. However, the thinner discharged from this feed tube has a drawback that the paint adhering to the outer peripheral surface of the bell cup cannot be washed.

Therefore, as a coating apparatus for solving this problem, there is, for example, one disclosed in Japanese Utility Model Publication No. 57-62659 (hereinafter referred to as other conventional technology). And
The other conventional coating device is equipped with a cleaning nozzle that discharges thinner toward the outer peripheral surface of the bell cup.
The paint adhered to the outer peripheral surface of the bell cup is cleaned by ejecting thinner from the cleaning nozzle toward the outer peripheral surface of the bell cup.

[0016]

By the way, in the above-mentioned other conventional coating apparatus, when cleaning the outer peripheral side of the bell cup, the rotary atomizing head is rotated toward the outer peripheral surface of the bell cup. It only discharges thinner. For this reason, the thinner discharged from the cleaning nozzle bounces on the outer peripheral surface of the bell cup, is difficult to fit on the outer peripheral surface of the bell cup, and the paint attached to the outer peripheral surface tip side of the bell cup cannot be reliably cleaned. There is a problem that there is.

Further, in order to eliminate the rebound of the thinner, the poor conformability, etc. and to reliably clean the paint adhering to the outer peripheral surface of the bell cup, the mounting position of the cleaning nozzle, the direction of the cleaning nozzle, the discharge amount of the thinner, etc. Must be set precisely,
There is a problem that it is difficult to design and manufacture, and advanced design and manufacturing technology is required.

Further, as in the case of the conventional coating apparatus, the outer circumference of the bell cup is provided despite the fact that the thinner is supplied from the feed tube inserted through the rotary shaft toward the inner circumference side of the bell cup. It is inefficient to separately provide a dedicated nozzle for cleaning the surface, and there are problems that the structure is complicated, the number of parts is increased, and the cost is increased.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to supply the solvent discharged from the feed tube from each solvent passage provided in the bell cup when cleaning the rotary atomizing head. It is an object of the present invention to provide a rotary atomizing head type coating device that can be surely washed off the paint adhering to the outer peripheral surface of the bell cup by using this solvent to flow out to the outer peripheral surface of the bell cup.

Another object of the present invention is to provide a rotary atomizing head in which the solvent flowing out to the outer peripheral surface of the bell cup is guided to the tip side of the bell cup by using assist air supplied from the tip side of the cover. To provide a mold coating device.

Still another object of the present invention is to ensure that when the solvent is discharged from the feed tube into the paint reservoir during cleaning of the rotary atomizing head, the solvent can be reliably supplied to each solvent passage provided in the bell cup. To provide a rotary atomizing head type coating device.

[0022]

A rotary atomizing head type coating apparatus according to the present invention comprises a cover formed in a cylindrical shape, an air motor provided in the cover, and an air motor inserted in the axial direction of the air motor. A rotary shaft which is rotated by the rotary shaft, a rotary atomizing head which is attached to the rotary shaft and rotates at a high speed by the rotary shaft, and which is disposed so as to extend in the rotary shaft in the axial direction. It consists of a feed tube that discharges paint or solvent from the extended tip.

Then, in order to solve the above-mentioned problems,
A feature of the configuration adopted by the invention of claim 1 is that the rotary atomizing head is provided at a bell cup formed in a bell shape or a cup shape, and is provided at an inner peripheral side of the bell cup. And a hub member defining a paint reservoir for accumulating the paint discharged from the feed tube, and a paint or solvent discharged from the feed tube from the paint reservoir inside the bell cup, the hub member being provided in the hub member. It is composed of a plurality of paint outflow holes that flow out to the tip side of the peripheral surface, and a plurality of solvent passages that are provided in the bell cup and that allow the solvent discharged from the feed tube to flow out from the paint reservoir to the outer peripheral surface of the bell cup. At the tip end side of the cover, an assist air blown out assist air for guiding the solvent flowing out from the solvent passages to the outer peripheral surface of the bell cup to the tip end side of the bell cup. In that a configuration in which the spout.

With this configuration, when coating is performed, the rotary atomizing head is rotated at high speed together with the rotary shaft, and the paint is discharged from the feed tube to the paint reservoir.
As a result, the paint discharged to the paint reservoir diffuses in the paint reservoir due to the centrifugal force, and flows out from the paint reservoir to the tip end side of the inner peripheral surface of the bell cup through the paint outlet holes provided in the hub member. Then, this paint is discharged as paint particles from the tip side of the inner peripheral surface of the bell cup after being made into a thin film, and the paint particles fly toward the object to be coated and adhere to the object to be coated.

Further, in the case of changing the paint to the next color paint, after washing the previous color paint adhered to the feed tube and the rotary atomizing head with the air / solvent, the next color paint is supplied to supply the paint. Fill the road.

In order to wash the paint adhering to the rotary atomizing head when the next color paint is supplied by temporarily stopping the coating work, etc., the rotary atomizing head is rotated and the above-mentioned air / solvent is used. Separately, the solvent is discharged from the feed tube toward the paint reservoir. And a part of the solvent supplied to the paint pool
The paint that has flowed out to the tip side of the inner peripheral surface of the bell cup through the paint outlet holes of the hub member and is attached to the tip side of the inner peripheral surface of the bell cup is washed.

On the other hand, a part of the solvent supplied to the paint reservoir flows into each solvent passage provided in the bell cup and flows toward the outer peripheral side of the bell cup through each solvent passage.
Then, this solvent flows out from each solvent passage to the outer peripheral surface of the bell cup and cleans the outer peripheral surface.

At this time, assist air is ejected from the assist air ejection port. For this reason, the solvent flowing out from each solvent passage tends to fly outward in the radial direction due to the centrifugal force due to the high speed rotation of the rotary atomizing head, but the outer periphery of the bell cup is ejected by the assist air ejected from the assist air ejection port. It is pressed against the surface. As a result, the solvent is introduced to the tip side of the bell cup and cleans the paint adhering to the tip side of the outer peripheral surface of the bell cup.

According to a second aspect of the present invention, a shaping air ejection port for ejecting shaping air is provided on the tip end side of the cover, and the assist air ejection port is located on the inner diameter side of the shaping air ejection port and the tip end of the cover. It is configured to be provided on the side.

With this configuration, the solvent in the bell cup flows from each solvent passage to the outer peripheral side of the bell cup. In this way, the solvent flowing out to the outer peripheral surface of the bell cup resists the centrifugal force due to the high speed rotation of the rotary atomizing head by the assist air ejected from the assist air ejection port and the shaping air ejected from the shaping air ejection port. Then, it is pressed against the outer peripheral surface of the bell cup and guided to the tip side of the bell cup. As a result, it is possible to prevent the solvent from scattering on the outer peripheral side of the bell cup, and it is possible to wash the paint adhered to the outer peripheral surface of the bell cup with this solvent.

According to the third aspect of the invention, an assist air passage through which the assist air from the pressure source flows and an exhaust air passage through which the exhaust air from the air motor flows are provided in the cover, and the assist air jet port is provided at the assist air ejection port. The configuration is such that the air from the assist air passage and the exhaust air passage are combined and supplied.

With this configuration, the assist air jet port is formed by using both the assist air from the compressed air source supplied through the assist air passage and the exhaust air from the air motor supplied through the exhaust air passage. Since the air can be ejected toward the outer peripheral surface of the bell cup on the front side, the exhaust air can be effectively used as assist air and the flow rate of assist air from the compressed air source can be reduced.

According to a fourth aspect of the present invention, a plug is detachably attached to the exhaust air passage so that the exhaust air passage is selectively communicated with and cut off from the assist air passage.

With this structure, when the plug is attached to the exhaust air passage, only the assist air supplied from the assist air passage is used.
On the other hand, when the plug is removed from the exhaust air passage, both assist air and exhaust air can be used.

According to a fifth aspect of the present invention, an assist air control means for controlling the flow rate or pressure of the assist air is provided between the assist air passage and the compressed air source.

With this configuration, the flow rate or pressure of the assist air can be adjusted by the assist air control means to an amount of air suitable for pressing the solvent against the outer peripheral surface of the bell cup.

According to a sixth aspect of the invention, a flange portion for dispersing the solvent discharged from the feed tube is provided on the tip side of the feed tube.

With this configuration, when the solvent is discharged from the feed tube during cleaning, the solvent collides with the collar portion and is dispersed, so that the solvent flows into each paint outflow hole provided on the outer peripheral side of the hub member. A large amount can be supplied, and the paint adhering to the liquid contact surface and the outer peripheral surface of the rotary atomizing head can be washed.

According to a seventh aspect of the present invention, a flange portion for dispersing the solvent discharged from the feed tube is provided on the tip side of the feed tube, and the flange portion is provided with a plurality of notches in the circumferential direction. It has been configured.

With this configuration, when the solvent is discharged from the feed tube during cleaning, some of the solvent flows straight through the notches formed in the flange, and other solvents flow straight. Are collided with and dispersed. From this, by adjusting the size, shape, number, etc. of each notch, the solvent discharged from the feed tube is distributed and supplied to each paint outflow hole, solvent outflow hole, and each solvent passage at a desired ratio. can do.

According to the invention of claim 8, an annular guide is provided on the outer peripheral surface side of the bell cup so as to surround the bell cup with a gap, and the inner peripheral surface of the annular guide and the bell cup are provided. A solvent diffusion chamber for diffusing the solvent flowing out from the solvent passage is provided between the outer peripheral surface and the outer peripheral surface.

With this configuration, when cleaning the rotary atomizing head, the solvent supplied into the paint reservoir flows through the solvent passage to the outer peripheral side of the bell cup. Then, this solvent flows out into the solvent diffusion chamber, diffuses around the entire circumference of the bell cup in the solvent diffusion chamber, and then flows out of the annular guide. Therefore, the solvent that has flowed out of the annular guide and diffused all around the bell cup is pressed against the outer peripheral surface of the bell cup by the assist air ejected from the assist air ejection port, and the front surface attached to the tip end side of the outer peripheral surface of the bell cup. Rinse the paint all around.

According to a ninth aspect of the present invention, the solvent diffusion chamber is provided with an annular protrusion for diffusing the solvent flowing in the solvent diffusion chamber over the entire circumference of the bell cup.

With this configuration, when the rotary atomizing head is washed, the solvent flowing in the solvent diffusion chamber is temporarily blocked by the annular projection, and the dam effect causes the solvent to flow over the entire circumference of the solvent diffusion chamber. Spread.

According to a tenth aspect of the present invention, an annular dam groove for temporarily storing the solvent flowing out from the solvent passage is provided on the outer peripheral surface side of the bell cup.

[0046]

DETAILED DESCRIPTION OF THE INVENTION A rotary atomizing head type coating apparatus according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 7 show a rotary atomizing head type coating apparatus according to the first embodiment of the present invention.

In the figure, reference numeral 1 denotes a cover which is the outer shape of a rotary atomizing head type coating apparatus, and the cover 1 is provided on a cover cylinder 2 formed in a thin cylindrical shape and on the front side of the cover cylinder 2. The shaping air ring 3 is generally included. Further, the cover cylinder 2 accommodates a front housing 6 and an air motor 8 which will be described later therein.

Further, the shaping air ring 3
2, is formed in a stepped cylinder shape, and a large number of shaping air ejection ports 4, 4, ... Are arranged in a row in an annular shape on the tip surface 3A thereof as shown in FIG. Further, the inner peripheral side of the tip end surface 3A of the shaping air ring 3 is located on the inner diameter side of each of the shaping air ejection ports 4, and the annular recess 3 is formed.
B, the rear side of the annular recess 3B is an accommodation recess 3C for accommodating the rear part of the rotary atomizing head 12 described later.

Reference numeral 5 denotes a shaping air supply passage extending from the front housing 6 to the shaping air ring 3. The shaping air supply passage 5 is located on the outer peripheral side of the front housing 6 and extends in the axial direction. 5A, an annular passage 5B formed between the front housing 6 and the cover cylinder 2, and a plurality of connecting passages 5C, 5C located on the outer peripheral side of the shaping air ring 3 and extending in the axial direction. , (And only two of them are shown) and an annular air chamber 5D that communicates with each of the communication passages 5C, and each shaping air ejection port 4 communicates with the air chamber 5D. The shaping air supply passage 5 is connected to a shaping air supply source (neither is shown) via an air pipe, a control valve, or the like.

Here, the shaping air is ejected from each shaping air ejection port 4 toward the outer peripheral side of the rotary atomizing head 12 to form a spray pattern of paint particles sprayed from the rotary atomizing head 12. To do. Also,
The shaping air removes thinner as a solvent flowing out from a thinner passage 18 to be described later when the rotary atomizing head 12 is washed,
The bell atomizing head 12 is pressed against the outer peripheral surface 13H of the bell cup 13 against the centrifugal force generated by the high speed rotation of the rotary atomizing head 12.
Also has the function of leading to the tip side.

Reference numeral 6 denotes a front housing which is housed in the cover cylinder 2 and is formed in the shape of a stepped cylinder having a bottom. Inside the front housing 6, a motor housing portion 6A for housing the air motor 8 is provided. A fixing ring 7 for fixing the air motor 8 in the motor housing portion 6A is screwed to the opening end side of the portion 6A.

Reference numeral 8 is an air motor housed in the motor housing portion 6A of the front housing 6, and the air motor 8 is
A stepped tubular motor housing 9 having a shaft insertion hole 9A extending in the axial direction and a turbine chamber 9B formed by enlarging the depth of the shaft insertion hole 9A, and a turbine chamber 9B of the motor housing 9. An air turbine 1 rotatably housed inside
0, an air bearing (not shown) that supports a rotating shaft 11 described later so as to be rotatable at high speed, and the like. Further, a high voltage is applied to the motor housing 9 via a high voltage cable 42 described later and the like.

Reference numeral 11 denotes a shaft insertion hole 9A of the motor housing 9.
The rotary shaft 11 is supported by a hollow rotary shaft inserted thereinto so as to be rotatable at high speed via an air bearing, and the base end side thereof is fitted to the air turbine 10. Further, the tip side of the rotary shaft 11 projects from the motor housing 9, and the rotary atomizing head 12 is attached to the tip thereof.

Reference numeral 12 is a rotary atomizing head attached to the rotary shaft 11, and the rotary atomizing head 12 includes a bell cup 13, which will be described later.
It is composed of a hub member 14, a paint outflow hole 15, a thinner outflow hole 16, a paint reservoir 17, a thinner passage 18, and the like.

Reference numeral 13 is a bell-shaped or cup-shaped bell cup that forms the outer shape of the rotary atomizing head 12 and expands from the rear side toward the front side. The bell cup 13 rotates at the rear side. Rotating shaft mounting portion 1 screwed to the tip of the shaft 11.
It is 3A. Also, in the center of the bell cup 13,
An annular partition wall 13B is formed so as to project inward in the radial direction, and the distal end of a feed tube 23, which will be described later, protruding from the distal end side of the rotary shaft 11 extends on the inner peripheral side of the annular partition wall 13B.

Furthermore, the inner peripheral side of the bell cup 13 is
The diameter gradually increases like a skirt from the annular partition wall 13B to the front end of the bell cup 13. The front side of the inner peripheral surface of the bell cup 13 serves as a paint thinning surface 13C for thinning the paint, and the tip end side of the paint thinning surface 13C serves as a discharge edge 13D for discharging the paint. The rear side of the inner peripheral surface of the bell cup 13 is a paint receiving surface 13E that receives paint or thinner. Further, the paint thin film surface 1
A hub mounting groove 13F is formed between 3C and the paint receiving surface 13E, and a guide mounting step portion 13G is formed on the outer peripheral side at an axially intermediate portion.

Reference numeral 14 denotes a hub mounting groove 13F of the bell cup 13.
Is a hub member that is fitted to the bell cup 13 to define a paint reservoir 17 between the bell cup 13 and the bell cup 13. The hub member 14 is formed in a disk shape and is disposed coaxially with the bell cup 13. The front surface 14A of the hub member 14 is a flat surface continuous with the paint thinning surface 13C of the bell cup 13, and the rear surface of the hub member 14 is a paint supply surface 14B.

Here, the coating film thinning surface 1 of the bell cup 13
3C, discharge edge 13D, paint receiving surface 13E, hub member 14
The liquid contact surface of the rotary atomizing head 12 is configured by the front surface 14A, the paint supply surface 14B, and the like.

.. are a plurality of paint outlet holes (only two are shown) arranged in an annular shape on the outer peripheral side of the hub member 14, and each paint outlet hole 15 is a feed tube 23. The paint or thinner discharged from the inner side of the bell cup 13 is discharged to the paint thinning surface 13C.

.. are thinner outlet holes (only two are shown) which are located at the center of the hub member 14 and serve as a plurality of solvent outlet holes penetrating from the paint supply surface 14B to the front surface 14A.
Each of the thinner outlet holes 16 is used for cleaning the rotary atomizing head 12,
The thinner discharged from the feed tube 23 to the inner peripheral side of the bell cup 13 flows out to the front surface 14A of the hub member 14.

Reference numeral 17 denotes a paint reservoir. The paint reservoir 17 is provided with a hub member 14 mounted in a hub mounting groove 13F of the bell cup 13 so that a paint supply surface 14B of the hub member 14 and a paint receiving surface 13E of the bell cup 13 are provided. It is defined between and. Here, the paint reservoir 17 is a space for temporarily collecting the paint or thinner discharged from the feed tube 23 and diffusing the paint or thinner.

.. are thinner passages (only two are shown) serving as solvent passages provided in a large number at predetermined intervals in the circumferential direction of the bell cup 13, and each of the thinner passages 18 has an inlet port 18A. Open on the paint receiving surface 13E of the bell cup 13,
The outflow port 18B opens to the outer peripheral surface 13H of the bell cup 13 and extends from the inner peripheral side of the bell cup 13 toward the outer peripheral side. As a result, each thinner passage 18 retains the thinner flowing into the paint reservoir 17 from the thinner supply passage 25 of the feed tube 23 when the rotary atomizing head 12 is washed.
It is made to flow from 7 toward the outer peripheral side of the bell cup 13.

Here, the inlet 18A of each thinner passage 18
As shown in FIG. 6, is opened at a position which is recessed from each paint outflow hole 15 by a constant dimension G. This allows
At the time of coating, the paint supplied from the paint supply passage 24 of the feed tube 23 to the paint reservoir 17 is prevented from flowing into the thinner passage 18, and at the time of cleaning, the thinner supplied from the thinner supply passage 25 to the paint reservoir 17 is removed. , Thinner passage 18
It is configured to allow inflow to.

Further, each thinner passage 18 has its inlet port 1
Bell cup 1 from 8A toward outlet 18B
3 is inclined to the rear side. That is, each thinner passage 18
The outlet 18B of the bell cup 13 is located on the rear side of the bell cup 13 and is open from the opening position of the inlet 18A. This prevents the paint from flowing into each thinner passage 18 during painting.

Further, as shown in FIG. 5, each thinner passage 18 inclines in the rotation direction of the rotary atomizing head 12 (direction indicated by an arrow A) from the inlet 18A toward the outlet 18B, and the rotary fog is rotated. It is provided so as to be twisted in the rotation direction of the phasic head 12. That is, each thinner passage 18 has a bell cup 13
Is inclined in the rotational direction so as to form a predetermined angle α in the range of 15 ° to 50 ° with respect to the radial direction.
As a result, when cleaning the rotary atomizing head 12, the paint reservoir 17
The thinner discharged inside easily flows into each thinner passage 18.

Reference numeral 19 denotes a guide mounting step portion 1 of the bell cup 13.
With an annular guide provided in 3G, the annular guide 19 is
The base side is a mounting part 19A mounted on the guide mounting step part 13G, and a bell-shaped or cup-shaped structure in which a fixed gap is formed between the mounting part 19A and the front side with the outer peripheral surface 13H of the bell cup 13. It is an expanded portion 19B that is expanded to.

Reference numeral 20 denotes a thinner diffusion chamber formed between the inner peripheral surface of the expanding portion 19B of the annular guide 19 and the outer peripheral surface 13H of the bell cup 13, and the thinner diffusion chamber 20 is the bell cup 13.
Is formed in an annular shape over the entire circumference thereof, and the outlet ports 18B of the respective thinner passages 18 are opened in the inner portion thereof.

Reference numeral 21 is an annular protrusion provided on the inner peripheral surface of the expanded portion 19B of the annular guide 19. The annular protrusion 21 is formed in an annular shape over the entire circumference of the annular guide 19 and has a bell cup shape. An annular throttle passage 22 is formed between the outer peripheral surface 13 </ b> H and 13 </ b> H. Then, the ring-shaped ridge portion 21 is used for the rotary atomizing head 12
During the cleaning, it acts as a dam that temporarily blocks the thinner that flows through the thinner diffusion chamber 20 toward the front side of the bell cup 13.

Reference numeral 23 denotes a feed tube axially inserted into the rotary shaft 11. The feed tube 23 is composed of an inner cylinder 23A and an outer cylinder 23B coaxially provided on the outer peripheral side of the inner cylinder 23A. It is formed in a heavy cylinder shape, and its base end side is fitted in the motor housing 9 of the air motor 8. Further, the tip end side of the inner cylinder 23A has a rotary shaft 11 and an outer cylinder 23B.
It projects from and extends into the paint reservoir 17 of the rotary atomizing head 12. A check valve 23C is provided on the tip end side of the outer cylinder 23B so that the tip end thereof elastically abuts the outer peripheral surface of the inner cylinder 23A and opens when thinner is supplied from the thinner supply passage 25. ing.

Here, the inside of the inner cylinder 23A serves as a paint supply passage 24 connected to a color changing valve device (neither is shown) via a paint pipe or the like, and the inner cylinder 23A and the outer cylinder 23B are provided.
Between them and is an annular thinner supply passage 25 connected to a thinner source (neither is shown) via a thinner pipe.

26 is an inner cylinder 23A of the feed tube 23.
The collar portion 26 is provided on the distal end side, and the collar portion 26 is the inner cylinder 23A.
Is formed as an annular protrusion having a semicircular arc-shaped cross section, which projects radially outward from the outer peripheral surface of the. Then, the collar portion 26 disperses this thinner by colliding the thinner discharged from the thinner supply passage 25, and supplies a large amount of thinner to the paint outflow holes 15 and the thinner passage 18 side located on the outer peripheral side. It is a thing. Further, some of the thinners are suppressed from scattering due to the flange portion 26 being formed in a semi-circular shape, and are supplied to the thinner outlet holes 16 side located in the central portion.

Reference numeral 27 is a rear housing provided on the rear side of the front housing 6, and the rear housing 27 is connected via a rear plate 28 to an arm 29 of a painting robot (not shown) or the like.

.. are a number of assist air jets provided in the shaping air ring 3, and each assist air jet 30 is located on the inner diameter side of each shaping air jet 4, as shown in FIG. They are arranged in an annular shape so as to be located and open to the annular recess 3B of the shaping air ring 3. And each assist air ejection port 30 is shown in FIG.
As shown in FIG. 3, the thinner flowing out from the thinner diffusion chamber 20 through the annular throttle passage 22 is passed through the outer peripheral surface 13H of the bell cup 13.
Assist air is jetted from the tip of the expanded portion 19B of the annular guide 19 to the tip of the outer peripheral surface 13H of the bell cup 13 so as to be pressed against.

Reference numeral 31 is an assist air passage for supplying air to each of the assist air ejection ports 30, and the assist air passage 31 extends axially on the outer peripheral side of the rear plate 28, the rear housing 27, and the front housing 6. An air supply passage 31A, an inclined passage 31B extending obliquely through the fixing ring 7 from the tip of the air supply passage 31A, and an inclined passage 31B communicated with the inclined passage 31B to define a space between the motor housing 9 and the fixed ring 7. The annular space 31C and the annular space 3
A plurality of communication passages 31D, 31D, ... Extending forward from 1C in the shaping air ring 3 (only two are shown)
And an air chamber 31E formed annularly at the tip of each communication passage 31D.
Each assist air ejection port 30 communicates with E.

Reference numerals 32 and 32 denote, for example, two exhaust air passages provided in the motor housing 9 of the air motor 8. Each exhaust air passage 32 exhausts the compressed air supplied to drive the air turbine 10 to rotate. However, the downstream side thereof is bifurcated into a first branch passage 32A and a second branch passage 32B. Then, each exhaust air passage 32
The first branch passage 32A of the front housing 6, the rear housing 27,
The outer peripheral side of the rear plate 28 communicates with an air discharge passage 33 that extends in the axial direction. Also, the second branch passage 32B
Opens to the front of the motor housing 9 and communicates with the annular space 31C of the assist air passage 31.

Here, 34 is a plug located at the open end of the air discharge passage 33 and detachably attached to the rear plate 28, and the plug 34 closes the air discharge passage 33,
As a result, the exhaust air from the air motor 8 is discharged from the second branch passage 32B of each exhaust air passage 32.

A female screw is engraved in the second branch passage 32B so that a plug (not shown) can be detachably attached. As a result, the air discharge passage 33 and the assist air passage 31 can be connected or disconnected. Therefore, if a plug is attached to the second branch passage 32B and the plug 34 is removed, a second embodiment described later is obtained.

Reference numeral 35 is an air pipe connected to the air supply passage 31A of the assist air passage 31, and the air pipe 35 is connected to a compressed air source 36 such as a compressor.

Reference numeral 37 denotes an assist air control unit which is provided in the middle of the air pipe 35 and serves as an assist air control means. The assist air control unit 37 includes an adjusting valve 38 provided in the middle of the air pipe 35 and the adjusting valve. The control unit 40 is connected to the control unit 40 via a lead wire 39. Then, the assist air control section 37 uses the control unit 40 to control each shaping air jet port 4.
By controlling the adjusting valve 38 based on a signal from the control unit 40, while considering the flow rate or pressure of shaping air ejected from the exhaust gas, the flow rate or pressure of exhaust air supplied from each exhaust air passage 32, and the like. The air supplied from the compressed air source 36 to the assist air passage 31 is controlled to an optimum value.

Here, since the compressed air has a relationship in which the pressure and the flow rate correspond to each other, a pressure adjusting valve, a flow rate adjusting valve or the like can be used as the adjusting valve 38. Then, the control unit 40 can control the valve opening degree of the adjustment valve 38 by feeding back the supply pressure in the air pipe 35.

Reference numeral 41 denotes the front housing 6 for detecting the number of rotations of the air turbine 10 of the air motor 8.
A detection cable is provided extending in the rear housing 27 and the rear plate 28 in the axial direction. Reference numeral 42 is a high-voltage cable inserted into the rear housing 27.
2 is connected to the motor housing 9 via a connection cable 43.

The rotary atomizing head type coating apparatus according to this embodiment has the above-mentioned structure. Next, the operation during coating will be described.

First, when painting, the air motor 8
Causes the rotary atomizing head 12 to rotate at high speed together with the rotary shaft 11. Then, the paint supply path 24 of the feed tube 23
The paint is discharged from the nozzle toward the paint reservoir 17 formed on the rotary atomizing head 12. As a result, the paint flowing into the paint reservoir 17 passes through each paint outflow hole 15 and flows out to the paint thinning surface 13C of the bell cup 13. Further, this paint is thinned on the paint thinning surface 13C, is discharged from the discharge edge 13D, and is atomized as paint particles.

At this time, a high voltage is applied to the motor housing 9 of the air motor 8 via the high voltage cable 42 and the connection cable 43, and the motor housing 9 and the rotary shaft 1
Since a high voltage is also applied to the rotary atomizing head 12 electrically connected via 1, an electrostatic field is formed between the rotary atomizing head 12 and the object to be grounded. It As a result, the charged paint particles atomized by the rotary atomizing head 12 fly along the electrostatic field and adhere to the object to be coated. Further, the spray pattern of the paint at the time of coating is formed into a desired pattern by the shaping air discharged from each shaping air jet port 4.

Next, the operation for changing the color of the paint to the next color will be described. In this case, the air thinner is supplied from the color change valve device so that the paint pipe and the paint supply passage 24,
After washing the previous color paint adhering to the rotary atomizing head 12, the next color paint is supplied from the color change valve device and filled in the paint supply passage 24 or the like.

However, when the next color paint is supplied as described above, this paint is discharged from the paint supply passage 24 into the rotary atomizing head 12, and the front surface 14A of the hub member 14 of the rotary atomizing head 12 and the bell. Paint may adhere to the outer peripheral surface 13H of the cup 13 or the like. Further, when the painting work is temporarily stopped due to a trouble in the painting line, a break during lunch break, etc., the paint adhered to the inner peripheral surface of the bell cup 13 of the rotary atomizing head 12 may be solidified. is there. Furthermore, when the same color paint is applied continuously for a long time, the rotary atomizing head 1
The paint adheres to 2 and accumulates.

In such a case, the paint adhered to the rotary atomizing head 12 is solidified and peels off at the time of coating to cause a coating failure. Therefore, the paint adhered to each part of the rotary atomizing head 12 Need to be washed.

Therefore, the operation for cleaning the paint adhering to each part of the rotary atomizing head 12 will be described.

First, at the time of cleaning the rotary atomizing head 12, the rotary atomizing head 12 is rotated together with the rotary shaft 11 by the air motor 8 to supply thinner from the thinner supply passage 25 of the feed tube 23. At this time, as shown in FIG. 6, the check valve 23C is opened, and the thinner is discharged from the thinner supply passage 25 to the paint reservoir 17.

Then, the thinner discharged from the thinner supply passage 25 collides with the flange portion 26 projecting in the radial direction at the tip portion of the inner cylinder 23A, and scatters in a wide range in the paint reservoir 17.
At this time, some of the thinners scattered in the paint reservoir 17 are supplied to the paint outflow holes 15 and the thinner passages 18 located on the outer peripheral side, and some thinners are used for the collar portion 26. Is formed in a semi-circular shape, scattering is suppressed, and the powder is supplied to each thinner outlet hole 16 side located in the central portion.

Therefore, the thinners scattered in the paint reservoir 17 and supplied to the respective paint outflow holes 15 side are
5, and then flows out to the paint thinning surface 13C of the bell cup 13 through each paint outflow hole 15. As a result, the thinner is discharged from the discharge edge 13D while cleaning the paint adhered to the paint thinning surface 13C and the discharge edge 13D.

Further, the thinner that has flowed into each thinner outlet hole 16 flows out to the front surface 14A of the hub member 14 through each thinner outlet hole 16 and cleans the paint adhering to the front surface 14A of the hub member 14. Then, this thinner flows through the paint film thinning surface 13C and is discharged from the discharge edge 13D.

On the other hand, the thinner that has flowed into the inflow port 18A of each thinner passage 18 is transferred to the outflow port 18B of each thinner passage 18.
Flows out radially outward of the bell cup 13. However, on the outer peripheral side of the bell cup 13, an annular guide 19 is provided over the entire circumference. Therefore, each thinner passage 18
The thinner flowing out of the flow guides the annular guide 19, flows through the thinner diffusion chamber 20 toward the front end side of the annular guide 19, and collides with the annular protrusion 21. As a result, the thinner is temporarily blocked by the dam effect of the annular protruding portion 21, and diffuses over the entire circumference of the bell cup 13 in the thinner diffusion chamber 20 by the centrifugal force.

The thinner in the thinner diffusion chamber 20 is
The bell cup 13 is formed by the expanding portion 19B of the annular guide 19.
Is guided to the front side of the bell cup, passes over the annular projection 21, passes through the annular throttle passage 22, and passes through the outer peripheral surface 13H of the bell cup 13.
Spill to.

At the time of cleaning the rotary atomizing head 12, air is supplied from the shaping air supply passage 5 to each shaping air jet 4, and each shaping air jet 4 is supplied.
Shaping air is ejected toward the outer peripheral side of the rotary atomizing head 12. Further, air is supplied from the pressure air source 36 to the assist air passage 31 through the air pipe 35, and exhaust air from the air motor 8 joins the air flowing through the assist air passage 31 and is supplied. Assist air is ejected from the ejection port 30 to the tip of the expanded portion 19B of the annular guide 19 to the tip of the outer peripheral surface 13H of the bell cup 13.

Therefore, the outer peripheral surface 13 of each bell cup 13
The thinner flowing out to H tries to scatter radially outward due to the centrifugal force due to the high-speed rotation of the rotary atomizing head 12, but the thinner flowing out is the assist air ejected from each assist air ejection port 30 and each shaping. The shaping air ejected from the air ejection port 4 presses the outer peripheral surface 13H of the bell cup 13. Thereby, the thinner is guided to the tip side along the outer peripheral surface 13H of the bell cup 13,
The paint attached to the tip side of the outer peripheral surface 13H of the bell cup 13 is washed.

The previous color painting operation, the color changing operation, and the next color painting operation are as shown in FIG. 7, and after the next color is supplied, the bell cup 13 is operated by the thinner and the assist air.
The case where the outer peripheral surface 13H of FIG.

Thus, according to the present embodiment, the thinner discharged to the paint reservoir 17 at the time of cleaning the rotary atomizing head 12 passes from the thinner passages 18 through the thinner diffusion chamber 20 to the outer peripheral surface of the bell cup 13. It flows out to 13H. At this time, the thinner uses the assist air ejected from each assist air ejection port 30 and the shaping air ejected from each shaping air ejection port 4 against the centrifugal force due to the high-speed rotation of the rotary atomizing head 12 to form a bell cup. It is pressed against the outer peripheral surface 13H of 13 and guided to the tip side of the bell cup 13.
As a result, the thinner can be supplied to the tip end side of the outer peripheral surface 13H of the bell cup 13 in a familiar state, and the adhered paint can be reliably washed.

As a result, as compared with the case where a separate cleaning nozzle is provided as described in the other prior art, it is possible to reduce the amount of thinner used and minimize the amount of thinner used, and to reduce the cleaning time. Can be shortened and the cleaning efficiency can be improved. Moreover, from the above, the coating apparatus according to the present embodiment can simplify the structure, reduce the number of parts, and reduce the cost.

Further, each assist air jet 30 is provided on the inner diameter side of each shaping air jet 4, and the assist air jetted from each assist air jet 30 and the shaping air jetted from each shaping air jet 4 are provided. Is sprayed toward the rotary atomizing head 12, the thinner can be reliably pressed against the outer peripheral surface 13H of the bell cup 13 by each air, and the cleaning efficiency of the adhered paint can be further improved.

Further, since the air supplied from the compressed air source 36 and the exhaust air discharged from the air motor 8 are used as the assist air ejected from each assist air ejection port 30, the exhaust air from the air motor 8 is also used. Can be effectively used as assist air. As a result, the flow rate of the assist air from the compressed air source 36 can be reduced, and the burden on the compressed air source 36 can be reduced.

Furthermore, since the air supplied from the compressed air source 36 is controlled by the assist air controller 37, the flow rate or pressure of the assist air ejected from each assist air ejection port 30 can be set to an optimum value. it can. Therefore, the thinner can be effectively pressed against the outer peripheral surface 13H of the bell cup 13, which also improves the cleaning efficiency.

On the other hand, the inner tube 23A of the feed tube 23
Since the flange portion 26 protruding outward in the radial direction is provided on the tip end side, a large amount of thinner can be supplied to each paint outflow hole 15 by colliding the thinner with the flange portion 26 and dispersing the thinner.
A part of the thinner can be supplied to each thinner outlet hole 16 and the thinner passage 18 side. As a result, a large amount of thinner can be supplied to the paint thinning surface 13C and the discharge edge 13D, which are the distribution channels of the paint and to which the paint is most attached.
It is possible to prevent cleaning failure due to insufficient supply of thinner, shorten the cleaning time, and improve cleaning efficiency, coating quality, production, and the like.

Next, FIGS. 8 and 9 show a second embodiment of the present invention. The feature of this embodiment is that the exhaust air from the air motor is not used as a part of the assist air but is discharged to the outside. However, only the air supplied from the compressed air source is ejected from the assist air ejection port. In addition, in the present embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 51 and 51 are exhaust air passages provided in the motor housing 9 of the air motor 8. The exhaust air passages 51 are the same as the exhaust air passages 32 described in the first embodiment. In addition, the first branch passage 51A and the second branch passage 51B with an internal thread are branched. Then, the first branch passage 51A opens to the outer periphery of the motor housing, and the front housing 6 and the rear housing 27 are formed.
Communicates with an air discharge passage 52 extending in the axial direction.
However, the plug 34 attached in the first embodiment does not exist in the air discharge passage 52, and is open rearward.

Further, 53, 53 are plugs detachably attached to the second branch passages 51B of the respective exhaust air passages 51, and the respective plugs 53 are provided with the second branch passages 51B as shown in FIG. Is blocked. As a result, the air motor 8
The exhaust air from is discharged rearward from the first branch passage 51A of each exhaust air passage 51 via the air discharge passage 52.

Therefore, the air supplied to each assist air jet port 30 is supplied from the compressed air source 36 to the assist air control section 37.
After the flow rate or pressure is adjusted with, the assist air passage 3
Only the air flowing through 1 is used.

Thus, also in the present embodiment having such a configuration, it is possible to obtain substantially the same operational effects as those of the first embodiment. However, in particular, in the present embodiment, exhaust air from the air motor 8 is exhausted rearward from each exhaust air passage 51 through the air exhaust passage 52. Therefore, the exhaust air from the air motor 8 whose amount of air fluctuates depending on the coating conditions is removed from the assist air, and only the air adjusted to a predetermined flow rate and pressure by the assist air controller 37 is used as assist air from each assist air ejection port 30. Can be ejected. As a result, the thinner for cleaning the outer peripheral surface 13H of the bell cup 13 can be pressed by the assist air adjusted to an appropriate amount of air to be made to fit well, and the cleaning efficiency can be improved.

Next, FIGS. 10 and 11 show the third embodiment of the present invention.
The embodiment of the present invention is characterized by the fact that the collar portion is provided with a plurality of notches in the circumferential direction. In addition, in the present embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 61 is a feed tube according to the present embodiment which is used in place of the feed tube 23 according to the first embodiment, and the feed tube 61 is the feed tube 23 described in the first embodiment. Similarly, the inner cylinder 61A and the outer cylinder 61B are formed in a double cylinder shape, the opening of the outer cylinder 61B is located rearward of the opening of the inner cylinder 61A, and the front end side of the outer cylinder 61B is formed. A check valve 61C is provided in the. Further, the inner cylinder 61A
A paint supply passage 62 is formed inside, and an annular thinner supply passage 63 is formed between the inner cylinder 61A and the outer cylinder 61B.

Reference numeral 64 denotes an outer cylinder 61B of the feed tube 61.
Of the inner cylinder 61A provided at the front end of the inner cylinder 61A at the open end of the inner cylinder 61A, and the flange 64 is substantially the same as the flange 26 of the first embodiment described above. Is formed so as to project radially outward from the outer peripheral surface of the. However, the collar portion 64 according to the present embodiment is different from the collar portion 26 according to the first embodiment in that the collar portion 64 has a rectangular cross-sectional shape and a notch portion 65 described later is formed.

Are a plurality of notches formed in the collar portion 64, and each notch portion 65 is, as shown in FIG.
Four flange portions 64 are provided in the circumferential direction at intervals of 90 °, for example. Further, each notch portion 65 is formed so as to penetrate the collar portion 64 in the axial direction.

As described above, the collar portion 64 according to the present embodiment.
10, when the thinner is discharged from the thinner supply passage 63 of the feed tube 61, a part of the thinner passes through each of the notches 65 and flows straight, and the center of the hub member 14 is discharged. It is supplied to each thinner outlet hole 16 formed in the section. Further, other thinners collide with the collar portion 64 to be dispersed, and each paint outflow hole 1 provided on the outer peripheral side of the hub member 14.
5. Supply to each thinner passage 18 opened in the paint receiving surface 13E of the bell cup 13.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operational effects as those of the first embodiment. However, particularly in this embodiment, the collar portion 64 is provided. Each notch portion 65 is provided. Therefore, by appropriately setting the size, shape, and number of the notches 65, the thinner discharged from the feed tube 61 is applied to each paint outflow hole 15, each thinner outflow hole 16, and each thinner passage 18 with each paint. Outflow hole 15> Each thinner outflow hole 16
> Distribution under the condition of each thinner passage 18 or each paint outflow hole 15> Each thinner outflow hole 16 = each thinner passage 18
Can be distributed and supplied under the following conditions. As a result, the paint adhering to each part can be effectively cleaned, the cleaning capacity such as the thinner usage amount and the cleaning time is improved, and the reliability of the rotary atomizing head type coating device is improved. can do.

Next, FIG. 12 shows a fourth embodiment of the present invention, which is characterized in that the annular guide is eliminated from the rotary atomizing head.

Reference numeral 71 is a rotary atomizing head according to the present embodiment, which is used in place of the rotary atomizing head 12 according to the first embodiment. The rotary atomizing head 71 includes a bell cup 72 and a hub member 73 which will be described later. , Paint outlet hole 74, thinner outlet hole 75, paint reservoir 76, thinner passage 77, annular dam groove 78, and the like.

Reference numeral 72 denotes a bell cup which is in the shape of the rotary atomizing head 71 and which is formed in a bell shape or a cup shape which expands from the rear side toward the front side. Almost the same as the bell cup 13 described in the embodiment,
Rotating shaft mounting portion 72A, annular partition wall 72B, paint thin film surface 7
2C, a discharge edge 72D, a paint receiving surface 72E, a hub mounting step portion 72F, and an outer peripheral surface 72G.

Reference numeral 73 denotes a hub mounting step portion 72 of the bell cup 72.
The hub member 73 is fitted in F, and the hub member 73 is formed in a disk shape substantially like the hub member 14 described in the first embodiment, and has a front surface 73A and a paint supply surface 73B. is doing. Further, a large number of paint outflow holes 74, 74, ... Are provided on the outer peripheral side of the hub member 73, and thinner outflow holes 75, 7 serving as a plurality of solvent outflow holes are provided at the center of the hub member 73.
5, ... (only two of each are shown) are provided. Further, the hub member 73 defines a paint reservoir 76 with the bell cup 72.

.. are thinner passages (only two are shown) serving as solvent passages provided at predetermined intervals in the circumferential direction of the bell cup 72, and each of the thinner passages 77 is the first passage. Similar to the thinner passage 18 described in the embodiment, the thinner flowing from the paint reservoir 76 into the inflow port 77A flows out from the outflow port 77B to the outer peripheral surface 72G of the bell cup 72.

Reference numeral 78 denotes an annular dam groove provided on the outer peripheral surface 72G of the bell cup 72. The annular dam groove 78 is formed as an annular V-shaped groove between each thinner passage 77 and the discharge end edge 72D. Has been done. Then, the annular dam groove 78 temporarily stores the thinner that has flowed out from each thinner passage 77, so that the thinner is stored on the outer peripheral surface 72G of the bell cup 72.
To evenly diffuse the

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. However, in the case of the present embodiment, each assist The assist air ejected from the air ejection port 30 is supplied from the annular dam groove 78 to the outer peripheral surface 7 of the bell cup 72.
The thinner may be supplied to the tip side and the thinner may be guided to the tip side of the bell cup 72.

In each of the above-described embodiments, the bell-shaped or cup-shaped rotary atomizing heads 12 and 71 that spread from the rear side toward the front side have been described as an example. The present invention may be applied to a long cylindrical rotary atomizing head, and in this case, by appropriately adjusting the direction of each assist air ejection port 30 in accordance with the shape of the rotary atomizing head, the above-described respective embodiments can be realized. Almost the same effect can be obtained.

Further, in each of the above-described embodiments, the direct charging type rotary atomizing head for applying a high voltage to the paint sprayed from the rotary atomizing heads 12, 71 via the air motor 8, the feed tubes 23, 61 and the like. Although the mold coating device was explained as an example, instead of this, an indirect charging type rotary fog that forms a corona discharge area in front of the rotary atomizing head by external electrodes and applies a high voltage to the sprayed paint It may be applied to a chemical head type coating device, or may be applied to a non-electrostatic rotary atomizing head type coating device.

Further, in each of the above-mentioned embodiments, the collar portion 2 is provided at the tip of the inner cylinder 23A, 61A of the feed tube 23, 61.
6 and 64 are described as being integrally provided, the present invention is not limited to this, and the flange may be provided as a separate body and attached to the inner cylinder by means of bonding, fitting, or the like. The collar part may be abolished.

Furthermore, in the third embodiment, the case where the four notches 65 are provided at 90 ° intervals in the collar 64 has been described as an example, but the present invention is not limited to this and, for example, Two, three, or five or more notches may be provided, and the shape and size thereof are not limited to those of the embodiment. That is, the size, shape, number, etc. of the notches 65 are appropriately set according to the discharge amount of the thinner, the distribution ratio to each part, and the like.

[0127]

As described in detail above, according to the first aspect of the invention, by ejecting the assist air from the assist air ejection port, the solvent flowing out from each solvent passage to the outer peripheral surface of the bell cup is removed. Therefore, it is possible to prevent the solvent flowing out from each solvent passage from spattering outward in the radial direction by the centrifugal force generated by the high speed rotation of the rotary atomizing head. As a result, it is possible to suppress the scattering of the solvent and make it conform to the outer peripheral surface of the bell cup, so it is possible to reliably wash the paint adhering to the outer peripheral surface of the bell cup with a small amount of solvent, and to minimize the amount of solvent used In addition, the cleaning efficiency can be improved by limiting the cleaning time.

According to the invention of claim 2, the assist air is jetted from the assist air jet port and the shaping air is jetted from the shaping air jet port, so that the solvent flowing out from each solvent passage is swept at high speed of the rotary atomizing head. It can be pressed against the outer peripheral surface of the bell cup against the centrifugal force due to rotation and guided to the tip side of the bell cup. As a result, it is possible to suppress the scattering of the solvent to the outer peripheral side, and it is possible to efficiently wash the paint adhered to the outer peripheral surface of the bell cup.

According to the third aspect of the present invention, the assist air supplied from the pressure air source through the assist air passage and the exhaust air supplied from the air motor through the exhaust air passage are joined to the assist air jet port. Since the air is supplied, the exhaust air of the air motor can be effectively utilized as a part of the assist air, the flow rate of the assist air from the pressure air source can be reduced, and the burden on the pressure air source can be reduced.

According to the fourth aspect of the present invention, since the plug can be removably attached to the exhaust air passage, the exhaust air passage can be selectively connected to and blocked from the assist air passage.

According to the invention of claim 5, since the flow rate or pressure of the assist air is controlled by the assist air control means, the assist air has an amount of air suitable for pressing the solvent against the outer peripheral surface of the bell cup. be able to. As a result, the flow rate and pressure of the assist air can be stabilized, so that the effect on the paint particles sprayed from the rotary atomizing head can be prevented and the coating quality can be improved.

According to the sixth aspect of the present invention, by providing the flange portion on the tip side of the feed tube, the solvent discharged from the feed tube can be collided with the flange portion and dispersed in the paint reservoir. A large amount of solvent can be supplied to each paint outflow hole provided on the outer peripheral side of the hub member, and the paint adhered to the liquid contact surface or outer peripheral surface of the rotary atomizing head can be washed in a short time. As a result, it is possible to prevent the cleaning failure of the paint due to the insufficient supply of the solvent, shorten the cleaning time, and improve the cleaning efficiency of the paint, the coating quality, and the productivity.

According to the invention of claim 7, a flange is provided on the distal end side of the feed tube, and a plurality of cutouts are provided in the flange in the circumferential direction, whereby one of the solvent discharged from the feed tube is removed. The part can be passed straight through each notch formed in the collar part, and other solvent can be collided with the collar part and dispersed in the paint reservoir. From this, by adjusting the size, shape, number, etc. of each notch, the solvent discharged from the feed tube is distributed and supplied to each paint outflow hole, solvent outflow path, and each solvent path at a desired ratio. Therefore, the paint adhered to the liquid contact surface or the outer peripheral surface of the rotary atomizing head can be effectively washed.

According to the eighth aspect of the present invention, an annular guide is provided on the outer peripheral surface side of the bell cup so as to surround the bell cup with a gap between the bell cup and the inner peripheral surface of the annular guide. Since the solvent diffusion chamber for diffusing the solvent flowing out from the solvent passage is provided between the bell cup and the outer peripheral surface, the solvent supplied into the paint reservoir passes through the solvent passage and the bell cup. While flowing to the outer peripheral side, this solvent,
It flows into the solvent diffusion chamber, diffuses around the entire circumference of the bell cup in the solvent diffusion chamber, and then flows out of the annular guide.
For this reason, the solvent that has flowed out of the annular guide and diffused over the entire circumference of the bell cup is pressed against the outer peripheral surface of the bell cup by the assist air ejected from the assist air ejection port,
It is possible to wash the front surface paint attached to the tip end side of the outer peripheral surface of the bell cup over the entire circumference.

According to the ninth aspect of the present invention, the solvent diffusion chamber is provided with the annular ridge portion for diffusing the solvent flowing in the solvent diffusion chamber over the entire circumference of the bell cup. The solvent flowing in the chamber is temporarily blocked by the annular protrusion, and can be diffused over the entire circumference of the solvent diffusion chamber by the dam effect.

According to the tenth aspect of the invention, the bell cup has an outer peripheral surface side provided with an annular dam groove for temporarily storing the solvent flowing out from the solvent passage. The assist air to be supplied can be supplied from the annular dam groove to the tip side of the outer peripheral surface of the bell cup to guide the solvent to the tip side of the bell cup.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a rotary atomizing head type coating apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing an enlarged main part of the rotary atomizing head type coating apparatus in FIG.

3 is a cross-sectional view of the rotary atomizing head type coating device as seen from the direction of arrows III-III in FIG.

FIG. 4 is a vertical cross-sectional view showing the rotary atomizing head in FIG.

5 is a cross-sectional view of the rotary atomizing head as seen from the direction of arrows VV in FIG.

FIG. 6 is an enlarged vertical sectional view of a main part in FIG. 2, showing a state in which the rotary atomizing head is being washed.

FIG. 7 is an operation explanatory view showing a coating operation and a cleaning operation.

FIG. 8 is a vertical sectional view showing a rotary atomizing head type coating apparatus according to a second embodiment of the present invention.

9 is an enlarged vertical sectional view showing a main part of the rotary atomizing head type coating apparatus in FIG.

FIG. 10 is an enlarged vertical sectional view of an essential part seen from the same position as in FIG. 6, showing a feed tube, a collar and the like according to a third embodiment of the present invention.

FIG. 11 is a side view showing the collar portion in FIG. 10 from the direction of the arrow XI-XI.

FIG. 12 is a vertical sectional view of a rotary atomizing head according to a fourth embodiment of the present invention seen from the same position as in FIG.

[Explanation of symbols]

1 cover 4 Shaping air outlet 8 air motor 11 rotation axis 12,71 rotary atomizing head 13,72 Bell cup 13H, 72G outer peripheral surface 14,73 Hub member 14A, 73A front 15,74 Paint outlet 16,75 thinner outlet (solvent outlet) 17,76 Paint reservoir 18,77 thinner passage (solvent passage) 23,61 Feed tube 26,64 Collar 30 Assist air jet 31 Assist air passage 32,51 exhaust air passage 36 Pressure source 37 Assist air control unit (assist air control means) 65 Notch

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-332415 (JP, A) JP-A-8-33859 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B05B 3/00-3/18

Claims (10)

(57) [Claims] 1. A cylindrical cover, an air motor provided in the cover, a rotary shaft that is inserted in the axial direction of the air motor and rotated by the air motor, and is attached to the rotary shaft. It consists of a rotary atomizing head that rotates at a high speed by a rotary shaft, and a feed tube that is disposed by extending in the rotary shaft in the axial direction and that discharges paint or solvent from the tip extending into the rotary atomizing head. In the rotary atomizing head type coating device, the rotary atomizing head is provided between a bell cup formed in a bell shape or a cup shape and an inner peripheral surface side of the bell cup, and between the bell cup. A hub member that defines a paint reservoir for accumulating the paint discharged from the feed tube, and a paint or solvent discharged from the feed tube from the paint reservoir, which is provided on the hub member. From a plurality of paint outflow holes that flow out to the tip side of the inner peripheral surface of the bell cup, and a plurality of solvent passages that are provided in the bell cup and that cause the solvent discharged from the feed tube to flow from the paint reservoir to the outer peripheral surface of the bell cup. And a configuration in which an assist air ejection port for ejecting assist air for guiding the solvent flowing out from the solvent passages to the outer peripheral surface of the bell cup to the tip side of the bell cup is provided on the tip side of the cover. A rotary atomizing head type coating device characterized in that 2. A shaping air ejection port for ejecting shaping air is provided on the front end side of the cover, and the assist air ejection port is located on the inner diameter side of the shaping air ejection port and provided on the front end side of the cover. The rotary atomizing head type coating device according to claim 1, which is configured. 3. An assist air passage through which assist air from a pressure source flows and an exhaust air passage through which exhaust air from the air motor flows are provided in the cover, and the assist air jet port is provided with the assist air passage. The rotary atomizing head type coating device according to claim 1 or 2, wherein the air from the air passage and the exhaust air passage are combined and supplied. 4. The rotary atomizing head mold according to claim 3, wherein a plug is detachably attached to the exhaust air passage to selectively connect and disconnect the exhaust air passage to the assist air passage. Coating equipment. 5. The rotary atomizing head type coating device according to claim 3, wherein an assist air control means for controlling the flow rate or pressure of the assist air is provided between the assist air passage and the compressed air source. 6. The rotary atomizing head type coating apparatus according to claim 1, wherein a flange portion for dispersing a solvent discharged from the feed tube is provided on a tip side of the feed tube. 7. A structure in which a flange portion for dispersing a solvent discharged from the feed tube is provided on a tip end side of the feed tube, and the flange portion is provided with a plurality of notches in a circumferential direction. Item 7. A rotary atomizing head type coating device according to Item 6. 8. An outer peripheral surface of the bell cup is provided with an annular guide which surrounds the bell cup with a gap therebetween, and an inner peripheral surface of the annular guide and an outer peripheral surface of the bell cup. 7. The rotary atomizing head type coating device according to claim 1, wherein a solvent diffusion chamber for diffusing the solvent flowing out from the solvent passage is provided between them. 9. The rotary atomizing head mold according to claim 8, wherein the solvent diffusion chamber is provided with an annular protrusion for diffusing the solvent flowing in the solvent diffusion chamber over the entire circumference of the bell cup. Coating equipment. 10. The rotary atomizing head mold according to claim 1, wherein an annular dam groove for temporarily storing the solvent flowing out from the solvent passage is provided on the outer peripheral surface side of the bell cup. Coating equipment.