The present invention relates to a rotary atomizer.
A rotary atomizer includes a rotating bell which is coupled to a rotating shaft of an air motor and has a plurality of orifices and a paint passage for supplying paint from a paint source to the orifices of the rotating bell, thus dispensing the paint through the orifices toward an object to be painted. In a painting operation, when the rotating shaft of the air motor and the rotating bell are rotated, the paint discharged through the orifices flows radially outwardly along a distal end face of the rotating bell, due to the centrifugal force, toward the peripheral edge of the rotating bell, then the paint is sprayed when separating from the peripheral edge of the rotating bell.
Recently, water-based paints have often been used instead of solvent-based paints in view of the state and local government regulations concerning environmental issues. A water-based paint, particularly, a quick-drying water-based emulsion paint turns into a gel immediately after the material has come into contact with the air. For example, when thirty minutes have passed after the start of painting operation, paint clots are deposited around the orifices, the distal end face and/or the outer periphery of the rotating bell, which causes a deformed pattern is deformed, which is a problem.
Further, when the supply of paint is stopped for a certain time period, the paint turns into a gel at the distal portion of the paint passage so that its paint port would be clogged.
In view of the above-mentioned problem of the prior art, an object of the present invention is to provide a rotary atomizer capable of avoiding the deposition of paint clots onto the distal end face of the rotating bell.
Further, another object is to provide a rotary atomizer capable of avoiding the clogging of a paint port at the distal portion of a paint passage.
According to the present invention, there is provided a rotary atomizer including a rotating bell secured to a rotating shaft of an air motor held in an atomizer body, the rotating bell defining a plurality of orifices for dispensing paint to an object to be painted, the rotation of the rotating bell atomizing the paint so as to spray the paint toward the object to be painted, the rotary atomizer comprising: a paint passage having a paint port, at a distal end thereof, fluidly communicating with the orifices of the rotating bell; a water passage disposed outside of the paint passage and having a water port, at a distal end of the water passage, fluidly communicating with the orifices of the rotating bell, and the paint and the water being simultaneously dispensed through the orifices of the rotating bell.
According to another aspect of the present invention, there is provided a rotary atomizer including a rotating bell secured to a rotating shaft of an air motor held in an atomizer body, the rotating bell having a plurality of orifices for dispensing paint to an object to be painted, the rotation of the rotating bell atomizing the paint so as to spray the paint toward the object to be painted, the rotary atomizer comprising: a paint passage having a paint port, at a distal end thereof, fluidly communicating with the orifices of the rotating bell; and a needle for opening and closing the paint port.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
With reference to the drawings, an embodiment of the present invention will be described below.
Referring to
The end plate 16 defines through holes 16a which are axially aligned with the screw holes 56 of the manifold 18. Further, within an internal space 14 of the atomizer body, three stays 26 extend parallel to the axis O. The stays 26 define, at the distal ends thereof, screw portions 26a which engages with the screw holes 56 of the manifold 18, and at the rear ends thereof, screw holes 26b which receive and engage with screw bolts 25. Thus, the manifold 18, the stays 26, the cylindrical cover 12 and the end plate 16 are assembled as illustrated in
Further, the rear end face of the manifold 18 includes a screw hole 18a engaging with a screw portion 28a at the end of a high voltage cable 28 for supplying a voltage to the rotary atomizer 10 to generate an electric field between the rotary atomizer 10 and the object to be painted. The rear end face further includes a first valve receptacle 18b for receiving a trigger valve 30, described below, a second valve receptacle 18c for receiving a gate valve 40, described below, and a plurality of exhaust ports 54. Further, a paint coupling 42, a water coupling 44, a turbine air coupling 46, a bearing air coupling 48, a brake air coupling 50 and a shaping air coupling 52 are attached to the rear end face of the manifold 18 by using a coupling method well-known in the art such as a screw coupling.
The end plate 16 defines a paint hole 60 and a water hole 62 through which a paint tube 218 (
The first valve receptacle 18b is a recess formed along the axis O in which the trigger valve 30 is accommodated. Further, a paint chamber 78 adjacent the first valve receptacle 18a opens into the end or bottom of the first valve receptacle 18b.
Further, a needle passage 80 fluidly connected to the paint chamber 78 in the manifold 18. The end of the needle passage 80 opposite to the paint chamber 78 opens into a pocket 88 which opens into a stopper receptacle 89. The stopper receptacle 89 opens into a motor receptacle 74 formed at the distal end of the manifold 18.
As stated above, the paint chamber 78 is a recess extending along the axis where one end opens into the first valve receptacle 18b and the opposite end opens into the pocket 88. A passage 82, fluidly communicating with the paint coupling 42, opens into the side wall of the recess. In this embodiment, the passage 82, the paint chamber 78 and the needle passage 80 provide a paint supplying passage.
The second valve receptacle 18c is an axially extending recess which is offset in the radial direction from the first valve receptacle 18b. The gate valve 40 is held in the second valve receptacle 18c. At a distal end portion of 40a, the outer surface of the gate valve 40 defines a peripheral groove 40b which opens into a radial passage 40c. The radial passage 40c is fluidly connected to an axially extending internal passage (not shown) of the end portion 40a.
Further, the gate valve comprises an axially reciprocating valve body 40d, for opening and closing the internal passage of the end portion 40a, and a coupling 41 for receiving air to activate the valve body 40d. Further, a passage 84, fluidly connected to the water coupling 44, opens into the side wall of the second valve receptacle 18c. Furthermore, the second valve receptacle 18c is fluidly connected via the passage 86 to the pocket 88.
A substantially cylindrical confluence member 90 is provided in the pocket 88.
The confluence member 90 includes a peripheral groove 90a formed in its outer surface, a central through hole 90b and a radial passage 90c extending between the central through hole 90b and the peripheral groove 90a. The passage 86 extending from the second valve receptacle 18c is positioned at the side wall of the pocket 88 so that the passage 86 opens into the peripheral groove 90a of the confluence member 90. In this embodiment, the passage 84, the peripheral groove 40b, the radial passage 40c, the internal passage of the end portion 40a, the passage 86, the peripheral groove 90a, the radial passage 90c and the central through hole 90b provide a water supplying passage.
Accommodated in the air motor receptacle 74 is an air motor 20 having a rotating shaft 20a extending along the axis O. A rotating bell 92 is secured to the rotating shaft 20a of the air motor 20. The air motor 20 incorporates a turbine (not shown) coupled to the rotating shaft 20a and driven by turbine air, as described below.
A dual-tube assembly 100 extends through the body portion and the rotating shaft 20a of the air motor 20 along the axis O. Referring to
The inner tube 102, the outer tube 104, the tip member 112 and the sleeve 106 are concentrically disposed around the axis O so that an annular outer passage 108 is defined between the inner tube 102 and the outer tube 104 to provide a water passage. At the rear end of the dual-tube assembly 100, the outer passage 108 is attached to the confluence member 90 so that the outer passage 108 is fluidly connected via the central through hole 90b of the confluence member 90 to the radial passage 90c.
The tip member 112 has an annular proximal end portion 112a and a tapered portion 112b coupled to the proximal end portion 112a. The tapered portion has a diameter gradually decreased toward the distal end and defines a paint port 112c fluidly connected to the inner passage 102. An inner surface of the tapered portion 112b, converging toward the distal end, provides a valve seat which sealingly contacts with a valve body 94a, described below. Further, in order to maintain the radial position of the sleeve 106 with respect to the tip member 112, a ring member 116 with a plurality of axial orifices (not shown) is arranged between the tip member 112 and the sleeve 106. Thus, an annular water port 114 is defined between the tip member 112 and the sleeve 106.
The trigger valve 30 comprises a pneumatically reciprocating valve stem 30a along the axis O and a coupling 32 which receives air for driving the valve stem 30a. Coupled to the distal end of the valve stem 30a is a needle 94 extending along the axis O and defining a valve body 94a at the distal end thereof. Thus, the needle 94 extends along the axis O from the valve stem 30a via the paint chamber 78, the needle passage 80 and the inner tube 102 of the dual-tube assembly 100 to the valve body 94a.
A rotating bell 92b is mounted to the rotating shaft 20a of the air motor 20. The rotating bell 92b includes, as well known in the art, a bell-shaped or cup-shaped distal end face 92b and a plurality of orifices 92a opening into the distal end face 92b.
Mounted on the distal end of the manifold 18 are an inner ring 22 enclosing the air motor 20 and an outer ring 24 arranged concentrically with the inner ring 22. A shaping air passage 23, fluidly connected to the shaping air coupling 52, is defined between the inner ring 22 and the outer ring 24.
With reference to
Provided on the turbine air tube 206 is a pneumatically-operating normally-closed ON/OFF valve 224 for controlling the supplying and shutting-off of turbine air. The opening and closing of the ON/OFF valve 224 is controlled by opening and closing a solenoid valve 228 provided on a control air tube 226. The bearing air tube 208 is continuously opened so that bearing air is continuously supplied to the air motor 20 from the activation to the shutoff of the compressor 204.
Provided on the brake air tube 210 is a pneumatically-operating normally-closed ON/OFF valve 236 for controlling the supplying and shutting-off of brake air. The opening and closing of the ON/OFF valve 236 is controlled by opening and closing a solenoid valve 240 provided on a control air tube 238.
Provided on the shaping air tube 212 is a pneumatically-operating normally-closed ON/OFF valve 242 for controlling the supplying and shutting-off of shaping air. The opening and closing of the ON/OFF valve 242 is controlled by opening and closing a solenoid valve 246 provided on a control air tube 244.
Provided on the first valve driving air tube 214 is a pneumatically-operating normally-closed ON/OFF valve 248 for controlling the supplying and shutting-off of air for driving the valve stem 30a. The opening and closing of the ON/OFF valve 248 is controlled by opening and closing a solenoid valve 252 provided on a control air tube 250.
Provided on the second valve driving air tube 216 is a pneumatically-operating normally-closed ON/OFF valve 254 for controlling the supplying and shutting-off of air for driving the valve stem 40d. The opening and closing of the ON/OFF valve 254 is controlled by opening and closing a solenoid valve 258 provided on a control air tube 256.
Paint is supplied by a paint pump 266 from a paint reservoir 268 via a paint tube 218 to the rotary atomizer 10. Provided on the paint tube 218 are a pneumatically-operating normally-closed ON/OFF valve 260 for controlling the supplying and shutting-off of paint and a circulation tube 268 for returning paint discharged from the paint pump 266 to the paint reservoir 268 when the ON/OFF valve 260 is closed. The opening and closing of the ON/OFF valve 260 is controlled by opening and closing a solenoid valve 264 provided on a control air tube 262. A power supply unit 272 supplies electrical power to the paint pump 266.
Water is supplied by a water pump 274 from a water tank 276 via a water tube 220 to the rotary atomizer 10. Provided on the water tube 220 are a pneumatically-operating normally-closed ON/OFF valve 230 for controlling the supplying and shutting-off of water and a circulation tube 278 for returning water discharged from the water pump 274 to the water tank 276 when the ON/OFF valve 230 is closed. The opening and closing of the ON/OFF valve 230 is controlled by opening and closing a solenoid valve 234 provided on a control air tube 232. A power supply unit 280 supplies electrical power to the water pump 274.
Herein after, the operation of the present embodiment will be described below.
In advance of starting a painting operation, the compressor 204, the paint pump 266 and the water pump 274 are activated. When the compressor 204 is activated, bearing air is supplied from header 202 via the bearing air tube 208 and the bearing air coupling 218 to the air motor 20 so that the rotating shaft 20a of the air motor 20 is suspended.
Next, when the ON/OFF valve 224 is opened, turbine air is supplied from the header 202 via the turbine air tube 206 and the turbine air coupling 46 to the air motor 20, to thereby rotate the rotating shaft 20a and the rotating bell 92 secured to the rotating shaft 20a. Next, when the ON/OFF valve 242 is opened, shaping air is supplied from the header 202 via the shaping air tube 206 and the shaping air coupling 32 to the shaping air passage 23 so that shaping air is discharged through the shaping air port 23a between the distal ends of the inner ring 22 and the out ring 24. In this connection, the supply of shaping air can be started at the same time as the supply of turbine air.
Water is supplied from the water tank 274 via the water tube 220 to the water coupling 44. Simultaneously, when the ON/OFF valve 254 of the second valve driving air tube 216 is opened, air is supplied from the header 202 via the second valve driving air tube 216 and the coupling 41 of the gate valve 40 to the gate valve 40, so that the valve body 40d thereof is forwardly driven, i.e., moved in the left direction in
When the ON/OFF valve 260 is opened, paint is supplied from the paint reservoir 268 via the paint tube 218 to the paint coupling 42. Further, when the ON/OFF valve 248 of the first valve driving air is opened, air is supplied from the header 202 via the first valve driving air tube 214 and the trigger valve 30 to the trigger valve 30 so that the valve stem 30a thereof is backwardly driven, i.e., moved in the right direction in
Note that the air motor 20 can be of a two speed type where the speed is increased when paint is supplied.
In the above-described embodiment, a water film is formed between the paint discharged through the orifices 92a and the distal end face 92b of the rotating bell 92, which would prevent paint clots from depositing on the distal end face 92b of the rotating bell 92.
Further, in a non-painting operation, since the paint port 112c is closed by the valve body 94a of the needle 94, the clogging of the paint port 112c in the prior art can be avoided.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application is a divisional of U.S. patent application Ser. No. 12/598,589, entitled “Rotary Atomizer,” filed on Nov. 2, 2009, which claims priority to and the benefit of PCT Application No. PCT/JP2007/059803 entitled “Rotary Atomizer,” filed on May 2, 2007, all of which are herein incorporated by reference in their entirety for all purposes.
Number | Name | Date | Kind |
---|---|---|---|
5122192 | Inukai et al. | Jun 1992 | A |
5707009 | Schneider | Jan 1998 | A |
6010084 | Yoshida et al. | Jan 2000 | A |
6179217 | Yoshida et al. | Jan 2001 | B1 |
7861945 | Yasuda et al. | Jan 2011 | B2 |
Number | Date | Country |
---|---|---|
H0544246 | Jun 1993 | JP |
H0563656 | Aug 1993 | JP |
06277571 | Oct 1994 | JP |
08001046 | Jan 1996 | JP |
2561529 | Dec 1996 | JP |
2790153 | Aug 1998 | JP |
2002214123 | Jul 2002 | JP |
3566584 | Sep 2004 | JP |
2004344889 | Dec 2004 | JP |
4347036 | Oct 2009 | JP |
Entry |
---|
PCT International Search Report and Written Opinion for PCT/JP2007/059803, dated Jun. 26, 2007. |
Machine translation of Notification of Reasons for Refusal for Japanese Patent Application No. 2009-513933 dated Aug. 24, 2012, 4 pages. |
Number | Date | Country | |
---|---|---|---|
20140134344 A1 | May 2014 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 12598589 | US | |
Child | 14158556 | US |