JP2002186883A - Rotary atomizing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contamination of the outer peripheral surface of a rotary atomizing head with paint and to wash the paint adhering to the outer peripheral surface for a short time by a small amount of a solvent. SOLUTION: A solvent sump 18 for storing the solvent supplied from the solvent supply passage 6 of a feed tube 4 and a paint sump 19 for storing the paint or solvent supplied from the paint supply passage 5 of the feed tube 4 are separately provided through the annular intermediate wall part 16A of an intermediate cylindrical part 16 and a solvent passage 21 for allowing the solvent to flow out to the outer peripheral surface 12C of a bell cup 12 is provided so as to be opened to the solvent sump 18. Therefore, the paint supplied to the paint sump 19 can be prevented from flowing out to a solvent passage 21 at the time of coating work. By this constitution, the paint can be prevented from adhering to the outer peripheral surface 12C of the bell cup 12 through the solvent passage 21 and a washing time and the use amount of the solvent can be reduced.

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 suitable for use in a coating apparatus for coating an object such as a vehicle body.

[0002]

2. Description of the Related Art In general, a coating apparatus using a rotary atomizing head has an air motor that rotates at a high speed by supplying air, a base end in an axial direction is rotatably supported by the air motor, and a tip end projects outside the air motor. A hollow rotary shaft, and a paint supply passage for discharging paint and a solvent supply passage for discharging a solvent for washing, which is provided extending in the axial direction in the rotation shaft so that the tip side protrudes from the rotation shaft. And a rotary atomizing head attached to the tip end of the rotary shaft and spraying the paint supplied from the paint supply path by rotating at a high speed together with the rotary shaft.

Here, as a rotary atomizing head, for example, the one shown in Japanese Patent Application Laid-Open No. H10-156224 is known. This conventional rotary atomizing head is formed in a bell shape or a cup shape, and the rear side of the inner peripheral surface becomes a paint receiving surface and the front side of the inner peripheral surface becomes a paint thinning surface for thinning the paint. A bell cup, a hub member provided on the inner peripheral side of the bell cup between the paint receiving surface and the paint thinning surface, and having a plurality of paint outlet holes, and the hub member and the paint receiving surface; And a paint pool for storing paint or solvent discharged from the nozzle, and an inflow side opening into the paint pool,
The outlet side is constituted by a plurality of solvent passages provided in the outer peripheral surface of the bell cup.

[0004] When a coating operation is performed by a coating apparatus having a rotary atomizing head according to the prior art configured as described above,
First, compressed air is supplied to the air motor to rotate the rotary atomizing head at high speed together with the rotary shaft. Then, the paint is discharged from the paint supply path of the nozzle toward the paint pool in the rotary atomizing head. As a result, the paint flows from the paint reservoir through the paint outlet hole of the hub member to the paint thinning surface, is sprayed from the discharge edge on the outer peripheral side of the paint thinning surface, and is applied to the workpiece.

On the other hand, when performing a color changing operation for changing the color of the paint to the next color paint, a solvent and air are supplied from a color changing valve device connected to the nozzle while the rotary atomizing head is rotated. And
The paint of the previous color remaining inside the paint supply path and the like is extruded and washed. Next, a solvent is discharged from the solvent supply passage of the nozzle into the paint pool inside the rotary atomizing head, and the paint of the previous color adhered to the paint pool, the paint outlet hole of the hub member, the liquid contact surface such as the paint thinning surface, etc. Wash. Then, when the cleaning of the previous color paint is completed, the paint of the next color is supplied to a paint supply path or the like to prepare for the next painting operation.

Here, when the paint is being sprayed from the rotary atomizing head, a part of the sprayed paint particles is used for shaping air for forming an air pumping phenomenon and a spray pattern due to high-speed rotation of the rotary atomizing head. Due to the influences generated in the peripheral area of the rotary atomizing head due to the above-mentioned factors, there is a case where the water flows backward so as to go backward from the discharge edge and adheres to the outer peripheral surface of the bell cup.

For this reason, the conventional rotary atomizing head is:
A part of the solvent supplied from the solvent supply passage of the nozzle to the paint reservoir flows out to the outer peripheral surface of the bell cup through the solvent passage, and the solvent is used to wash the paint adhered to the outer peripheral surface of the bell cup.

[0008]

In the above-described rotary atomizing head according to the prior art, when cleaning the bell cup, a solvent is supplied to a paint reservoir and the solvent flows out to the outer peripheral surface of the bell cup through a solvent passage. As a result, the paint adhered to the outer peripheral surface of the bell cup is washed with the solvent.

However, since the solvent passage is open to the paint reservoir from which the paint is discharged during the painting operation, even if the solvent passage opens in the back of the paint reservoir and is separated from the paint outlet, Part of the paint in the paint pool flows into the solvent passage,
There is a problem that it flows out to the outer peripheral surface of the bell cup through the solvent passage, and the outer peripheral surface of the bell cup is stained with paint.

In addition, when the flow rate of the paint discharged into the paint reservoir is large, a large amount of paint that cannot be discharged from the paint outlet hole flows into the solvent passage and travels along the outer peripheral surface of the bell cup to the discharge edge. And may be sprayed as paint particles from the discharge edge. However, the paint particles formed in this way are different from paint particles formed by spraying from the discharge edge, and have various uneven paint particle diameters, paint particle dispersibility, etc. Because of the factors, there is a problem that the coating quality is significantly reduced.

Furthermore, the solvent discharged into the paint reservoir during the cleaning operation first cleans the paint adhered to the inner surface of the paint reservoir, so that the solvent mixed with the paint flows into the solvent passage. For this reason, since the dirty solvent is supplied to the outer peripheral surface of the bell cup for a while after the cleaning operation is started, the cleaning efficiency is poor, and many cleanings are required until the paint adhered to the outer peripheral surface is completely cleaned. There is a problem that time is consumed with a solvent.

On the other hand, if the paint adhered to the outer peripheral surface of the bell cup is to be washed while the same paint is being applied without performing color change, the solvent is removed from the paint pool, the hub member, and the like.
Since the paint thinner surface and the like are also cleaned together, only the outer peripheral surface of the bell cup cannot be cleaned, and there is a problem that a solvent is wasted more than necessary.

[0013] 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 allow paint to flow out to the outer peripheral surface of a bell cup through a solvent passage and adhere to the outer peripheral surface of the bell cup. It is another object of the present invention to provide a rotary atomizing head capable of improving reliability and coating quality by preventing spraying toward an object to be coated.

Another object of the present invention is to reduce the amount of solvent used and the cleaning time by cleaning the paint adhering to the outer peripheral surface of the bell cup by using a solvent having a high cleaning ability in which no paint is mixed. It is to provide a rotary atomizing head which can be made.

Another object of the present invention is to reduce the amount of solvent used by cleaning only the outer peripheral surface of the bell cup when the same paint is used without performing color change. It is to provide a rotary atomizing head which can be made.

[0016]

In order to solve the above-mentioned problems, a rotary atomizing head according to the first aspect of the present invention is formed in a bell shape or a cup shape, and has an annular shape located on the inner peripheral side on the rear side. A bell cup in which an annular intermediate wall portion located intermediately with the rear wall portion and a front wall portion located on the front side and having a plurality of paint outlet holes are provided axially separated from each other; an annular rear wall portion of the bell cup And a solvent reservoir defined between the annular intermediate wall portion and the solvent discharged from the nozzle, and separately defined between the annular intermediate wall portion and the front wall portion of the bell cup. A paint reservoir for storing paint discharged from the nozzle, and a paint thinner provided from the front wall of the bell cup to the front end of the bell cup, and for thinning paint flowing out of the paint reservoir through a paint outlet hole. Surface and the inflow side are open to the solvent reservoir, and the outflow side is forward. Lies in the configuration by the solvent passage of a plurality of provided open to the outer peripheral surface of the bell cup.

With this configuration, when performing a painting operation, the rotary atomizing head is rotated at a high speed, and the paint is discharged from the nozzle into the paint reservoir. At this time, since the paint reservoir is provided separately from the solvent reservoir by the annular intermediate wall portion, it is possible to prevent the paint in the paint reservoir from accumulating in the solvent and flowing out to the solvent passage side. . The paint discharged into the paint reservoir flows out through the paint outlet hole in the front wall to the paint thinning surface of the bell cup, and paint particles from the discharge edge provided on the outer peripheral side of the paint thinning surface. And sprayed on the object.

Next, when performing a color changing operation for changing the color of the paint to the next color paint, the previous color paint adhered to the rotary atomizing head is washed. The cleaning operation includes two types, an inner peripheral surface cleaning operation for cleaning the inner peripheral surface of the rotary atomizing head, and an outer peripheral surface cleaning operation for cleaning the outer peripheral surface.

First, in order to perform the inner peripheral surface cleaning operation, a cleaning solvent is discharged from a nozzle into the paint reservoir. As a result, the solvent sequentially flows through the paint pool, the paint outlet holes, and the paint thinning surface, and cleans the precolor paint adhered to these liquid contact surfaces. At this time, since the paint reservoir is provided separately from the solvent reservoir, it is possible to prevent the stained solvent that has been cleaned by cleaning the paint reservoir from accumulating in the solvent and flowing out to the solvent passage side.

Next, to perform the outer peripheral surface cleaning operation, a cleaning solvent is discharged from a nozzle into a solvent reservoir. This allows
The solvent flows from the solvent reservoir through the solvent passage to the outer peripheral surface of the bell cup, and cleans the precolor paint adhered to the outer peripheral surface of the bell cup. At this time, since the solvent reservoir is provided separately from the paint reservoir, a solvent having a high cleaning ability, in which the washed paint is not mixed, can be used for cleaning, and the color of the front color adhered to the outer peripheral surface of the bell cup can be used. The paint can be efficiently washed.

Further, in the case where the coating operation is continued using the same coating material without performing color change, if it is necessary to wash the coating material adhered to the outer peripheral surface of the bell cup, the solvent is supplied from the nozzle only to the solvent pool. Discharge. Thereby, only the paint adhered to the outer peripheral surface of the bell cup by the solvent flowing out to the outer peripheral surface of the bell cup through the solvent passage can be washed.

According to the second aspect of the present invention, an annular solvent guide for guiding the solvent flowing out of each solvent passage toward the outer peripheral surface of the bell cup is provided on the outer peripheral side of the bell cup.

With this configuration, the annular solvent guide guides the solvent flowing out of each solvent passage and scattered in the radial direction toward the outer peripheral surface of the bell cup. Thus, the paint adhered to the outer peripheral surface of the bell cup can be efficiently cleaned.

According to the third aspect of the present invention, each solvent passage is
The configuration is such that the bell cup is inclined rearward from the inflow side to the outflow side.

With this configuration, since the extending direction of each solvent passage is different from the centrifugal direction (radial direction) of the rotary atomizing head and is inclined toward the rear side, the solvent passage is supplied to the solvent reservoir. The solvent can be uniformly flowed out by using the resistance due to the inclination without flowing out the solvent at once by centrifugal force, and the paint adhered to the outer peripheral surface of the bell cup can be washed evenly with a small amount of the solvent. .

According to the fourth aspect of the present invention, the solvent flowing out of each solvent passage is diffused on the outer peripheral surface by blowing solvent diffusion air from the rear side of the bell cup toward the outer peripheral surface of the bell cup. I did it.

[0027] With this configuration, the solvent flowing out of each solvent passage is pressed against the outer peripheral surface of the bell cup by the solvent diffusion air, and is diffused and spread on the outer peripheral surface to have a uniform film thickness. The solvent spreads and adheres to the entire outer peripheral surface and is washed without leaving any paint.

[0028]

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

First, FIGS. 1 to 3 show a first embodiment of the present invention. Reference numeral 1 denotes a coating machine cover for covering the outer periphery of the rotary atomizing head type coating apparatus. The coating machine cover 1 is formed in a cylindrical shape, and accommodates an air motor 2 described later therein.

Reference numeral 2 denotes an air motor housed in a coating machine cover 1. The air motor 2 includes a motor casing 2A formed in a cylindrical shape, an air turbine housed in the motor casing 2A, and a rotating shaft described later. 3 is rotatably supported by a static pressure air bearing (both not shown). The air motor 2 drives the rotating shaft 3 to rotate at high speed, for example, 3000 to 100000 rpm by supplying compressed air to the air turbine.

Reference numeral 3 denotes a hollow rotary shaft rotatably supported by a static pressure air bearing of the air motor 2. The front end of the rotary shaft 3 projects forward of the air motor 2, and a male screw is engraved on the outer peripheral side of the front end. Have been. The base end of the rotating shaft 3 is attached to an air turbine of the air motor 2.

Reference numeral 4 denotes a feed tube as a nozzle provided in the rotary shaft 3 so as to extend in the axial direction. As shown in FIG. 2, the feed tube 4 is located at the center of rotation and has a tip portion to be described later. A long inner cylinder 4A extending to the sump 19,
The inner cylinder 4A is provided coaxially on the outer peripheral side, and is formed in a double cylindrical shape with a short outer cylinder 4B having a distal end portion extending to a solvent reservoir 18 described later. The distal end of the outer cylinder 4B is a check valve 4C whose distal end elastically contacts the outer peripheral surface of the inner cylinder 4A and opens when a solvent is supplied from a solvent supply path 6 described later. .

Here, the feed tube 4 has an inner cylinder 4A.
Is a paint supply path 5, and an annular solvent supply path 6 is between the inner cylinder 4A and the outer cylinder 4B. The feed tube 4 is, for example, similar to the feed tube described in JP-A-6-277571.
Is connected to a color changing valve device via a pipe, a valve, and the like, and the solvent supply path 6 is connected to a solvent supply source (neither is shown) via a pipe, a valve, or the like. Thereby, the paint supply path 5
Discharges a paint or a solvent such as thinner used for cleaning and air into the paint reservoir 19, and the solvent supply path 6 discharges the solvent to the solvent reservoir 18.

Reference numeral 7 denotes a shaping air ring attached to the tip end of the coating machine cover 1. The shaping air ring 7 is formed in a cylindrical shape with a front side recessed in a mortar shape. Further, a large number (only two are shown) of air ejection holes 7A, 7A,... Are formed in the circumferential end portion of the shaping air ring 7 on the outer peripheral side. This air ejection hole 7A
Are connected to an air source (not shown) via a shaping air passage 8. The air ejection hole 7A ejects shaping air for controlling a spray pattern and the like of paint particles sprayed from a rotary atomizing head 11 described later.

Are a number of solvent diffusion air ejection holes (only two are shown) provided on the shaping air ring 7 at an inner peripheral side of each air ejection hole 7A.
Each of the solvent diffusion air ejection holes 9 is provided with a bell cup 12 described later.
Are located rearward of the outer peripheral surface 12C and are arranged in a row in the circumferential direction. Each of the solvent diffusion air ejection holes 9 is formed to be inclined outward in the radial direction at a position near the outer peripheral side of an annular solvent guide 22 described later.

The solvent-diffusing air ejection hole 9 uses air supplied from an air source via the dispersion air passage 10 as solvent-diffusing air, and directs this air toward the vicinity of the outer peripheral end of the annular solvent guide 22 to form the bell cup 12. It is sprayed from the rear. As a result, the solvent diffusion air spreads while spreading the solvent flowing out of each solvent passage 21 on the outer peripheral surface 12C of the bell cup 12 while pressing the solvent against the outer peripheral surface 12C to make a uniform film thickness, and spreads the solvent at the tip of the outer peripheral surface 12C. I will guide you to.

Next, reference numeral 11 denotes a rotary atomizing head according to the present embodiment, which is attached to the tip of the rotating shaft 3.
Reference numeral 1 denotes a bell cup 1 to be described later, as shown in FIGS.
2, solvent pool 18, paint pool 19, paint thinning surface 20,
It is roughly constituted by a solvent passage 21, an annular solvent guide 22, and the like.

Reference numeral 12 denotes a bell-shaped hollow bell cup which expands from the rear side toward the front side. The bell cup 12 has a rear-side mounting cylinder 12A and a front-side bell-shaped expansion. An opening 12B is provided. Here, the mounting cylinder portion 12 </ b> A is formed in a cylindrical shape, and a female screw to be screwed into a male screw provided at the tip of the rotating shaft 3 is engraved in a deep portion on the inner peripheral side. Further, the bell-shaped expanding portion 12B is formed such that an outer peripheral surface 12C of the bell-shaped expanding portion 12B is widened and widened forward in a bell shape from the mounting cylinder portion 12A.

Reference numeral 13 denotes an annular rear wall provided on the inner peripheral side of the bell cup 12, and the annular rear wall 13 is provided with a mounting cylinder 12A.
And is located on the rear side, which is the boundary between the bell-shaped expanding portion 12B, and protrudes inward. In addition, an arc surface 14 is provided on the front side of the annular rear wall portion 13 for smoothly flowing the solvent in a solvent reservoir 18 described later.

Here, the annular rear wall portion 13 is
A and a later-described solvent reservoir 18 are separated from each other, and the central portion thereof is an outer cylinder insertion hole 13A through which the outer cylinder 4B of the feed tube 4 is inserted with a small gap. Further, a portion of the annular rear wall portion 13 near the front side protrudes forward in order to prevent the solvent from entering the rotating shaft 3.

Reference numeral 15 denotes a mounting step provided at the front side of the arc surface 14 and provided at the front of the bell-shaped enlarged portion 12B.
The mounting step 15 is for positioning an intermediate tubular section 16 described later.

Reference numeral 16 denotes an intermediate cylindrical portion mounted in the mounting step 15 of the bell cup 12 by means such as press fitting. The intermediate cylindrical portion 16 constitutes a part of the bell cup 12. The intermediate cylindrical portion 16 forms a bottom portion, is located at an intermediate position in the axial direction of the bell cup 12, and separates a later-described solvent reservoir 18 and a paint reservoir 19 from each other. A cylindrical portion 16B protruding forward from the outer peripheral side is formed in a cylindrical shape with a bottom, and the inner peripheral side of the cylindrical portion 16B is a paint guide surface 16C that gradually opens toward a paint outlet hole 17B described later. I have. In addition, the annular intermediate wall portion 16A
The central portion of the inner tube 4 has an inner tube insertion hole 16D through which the inner tube 4A of the feed tube 4 is inserted with a small gap. Further, the center of the annular intermediate wall portion 16A near the front side is coated with paint,
In order to prevent the solvent from penetrating into the rotating shaft 3, it protrudes forward.

Reference numeral 17 denotes the bell cup 1 together with the intermediate cylindrical portion 16.
The front plate 17 is formed in a disk shape as a front plate as a front wall portion attached to the opening side of the second mounting step portion 15 by means such as press-fitting. In the center of the rear surface of the front plate 17, a conical projection 17A for facilitating paint reception is provided.
Are formed. Further, on the outer peripheral side of the front plate 17,
A large number of paint outflow holes 17B, 17B,... Through which paint and solvent flow out to the paint thinning surface 20 of the bell cup 12 are provided.
In the center part, a solvent outlet hole 17C for discharging the solvent to the front surface,
17C,... (Only two are shown).

Here, the annular rear wall portion 13, the annular intermediate wall portion 16A of the intermediate cylindrical portion 16, and the front plate 17 forming the front wall portion include:
Each of the bell cups 12 constitutes a bell cup 12 and is disposed apart from the bell cup 12 in the axial direction.

Reference numeral 18 denotes a solvent reservoir defined between the annular rear wall portion 13 of the bell cup 12 and the annular intermediate wall portion 16A of the intermediate cylindrical portion 16. The solvent reservoir 18 is formed on the front surface of the annular rear wall portion 13. , Is formed as a donut-shaped space surrounded by the rear surface of the annular intermediate wall portion 16A and the arc surface 14 and having the feed tube 4 disposed at the center thereof. The solvent reservoir 18 is formed separately and separately from a paint reservoir 19 described later. The solvent reservoir 18 temporarily stores the solvent discharged from the solvent supply passage 6 of the feed tube 4,
This is a space for diffusing this solvent.

Reference numeral 19 denotes an annular intermediate wall portion 16A of the intermediate cylindrical portion 16.
A paint reservoir defined separately from the solvent reservoir 18 between the inner peripheral surface of the intermediate cylindrical portion 16, the front surface of the annular intermediate wall portion 16 </ b> A, and the rear surface of the front plate 17. It is formed as an enclosed deep dish-shaped space. The paint pool 19 is a space for temporarily storing the paint or the solvent discharged from the paint supply path 5 of the feed tube 4 and diffusing the paint or the solvent.

Reference numeral 20 denotes a paint thinning surface provided from the front plate 17 to the front end of the bell cup 12, and the paint thinning surface 20 is formed by expanding in a disk shape. The leading end of the paint thinning surface 20 is a discharge edge 20A for discharging the paint thinned. Then, the paint thinning surface 20
Is to thin the paint flowing out from the paint outlet hole 17B of the front plate 17 and spray it as paint particles from the discharge edge 20A.

Are a plurality of solvent passages (only two are shown) provided in the bell cup 12, and each of the solvent passages 21 is located on the rear side of the bell cup 12 from the inflow side to the outflow side. So that the inflow side is
8 (circular surface 14), and the outflow side is open toward the rear of the outer peripheral surface 12C. Each solvent passage 21 allows the solvent supplied to the solvent reservoir 18 to flow out to the outer peripheral surface 12 </ b> C of the bell cup 12.

Here, since each solvent passage 21 is inclined rearward from the inflow side to the outflow side, the direction of extension of each solvent passage 21 is determined when the rotary atomizing head 11 is rotating. Is different from the centrifugal direction (radial direction). Accordingly, the solvent supplied to the solvent reservoir 18 can be uniformly flowed out to the outer peripheral surface 12C by using the resistance due to the inclination without flowing out the solvent supplied to the solvent reservoir 18 at a stretch by centrifugal force.

On the other hand, reference numeral 22 denotes an annular solvent guide mounted on the outer peripheral side of the bell cup 12 adjacent to the rear side of the solvent passage 21. The annular solvent guide 22 has an inner surface corresponding to the inclination of each solvent passage 21. The outer peripheral side is inclined forward toward the outer peripheral surface 12 </ b> C of the bell cup 12 while the peripheral side is inclined rearward. The annular solvent guide 22 guides the solvent flowing out of each solvent passage 21 and scattered in the radial direction toward the outer peripheral surface 12C of the bell cup 12 toward the front side.

The rotary atomizing head type coating apparatus according to the present embodiment has the above-described configuration. Next, a coating operation and a color changing operation will be described.

First, a description will be given of a case in which a coating operation of spraying a coating material on an object is performed. In this painting operation, the rotary atomization head 11 is driven to rotate at high speed, for example, 3000 to 100000 rpm by the air motor 2 together with the rotary shaft 3. In this state, when the paint supplied from the color changing valve device is supplied from the paint supply path 5 of the feed tube 4 to the paint reservoir 19 of the rotary atomizing head 11, the paint is diffused while staying in the paint reservoir 19. Since the paint reservoir 19 is provided separately from the solvent reservoir 18 by the annular intermediate wall portion 16A of the intermediate cylinder portion 16, the paint diffused in the paint reservoir 19 does not flow out to the solvent reservoir 18 side. Front plate 17
And flows out to the paint thinning surface 20 of the bell cup 12 through the paint outflow hole 17B. Further, the paint is uniformly thinned on the paint thinning surface 20, and is sprayed as paint particles from the discharge edge 20A.

At this time, for example, a high voltage is applied to the rotary atomizing head 11, and electric lines of force are formed from the rotary atomizing head 11 toward the object connected to the ground. The paint particles sprayed from the head 11 fly along the lines of electric force and apply to the object to be coated. Further, the spray pattern of the paint particles at this time is formed into a desired spray pattern by shaping air ejected from each air ejection hole 7A of the shaping air ring 7.

Next, a description will be given of a color changing operation for changing the color of the paint of the next color after the coating operation of the previous color is completed.

First, a cleaning operation for cleaning the precolor paint adhered to the rotary atomizing head 11 is performed. This cleaning operation includes two types, an inner peripheral surface cleaning operation for cleaning the inner peripheral surface of the rotary atomizing head 11, and an outer peripheral surface cleaning operation for cleaning the outer peripheral surface 12C of the bell cup 12.

Therefore, in order to perform the inner peripheral surface cleaning work, air and a solvent are alternately supplied from the color changing valve device to the paint supply path 5 of the feed tube 4 before the paint remains in the paint supply path 5 and the like. The color paint is extruded and the paint adhered in the passage is washed. In addition, the solvent discharged from the paint supply path 5 is supplied to the paint reservoir 19, the paint outlet 17 </ b> B of the front plate 17, and the bell cup 1.
The pre-color paint adhered to these liquid-contact surfaces is washed by sequentially flowing through the paint thinning surface 20 and the like. Again, paint pool 19
Is provided separately from the solvent reservoir 18, so that the solvent that has been cleaned and stained by the paint reservoir 19 and the like is removed from the solvent reservoir 18,
It does not flow out to the solvent passage 21 side.

On the other hand, to perform the outer peripheral surface cleaning work, a cleaning solvent is discharged from the solvent supply passage 6 of the feed tube 4 to the solvent reservoir 18. Here, the solvent pool 18 is the paint pool 1
9, the solvent supplied to the solvent reservoir 18 does not flow out to the paint reservoir 19 and is not contaminated by the paint, but stays in the solvent reservoir 18 and diffuses. , Flows into each solvent passage 21 by centrifugal force. Then, the bell cup 1 passes through the solvent passage 21.
The solvent that has flowed out to the outer peripheral surface 12C flows along the outer peripheral surface 12C. A part of the solvent tends to scatter in the radial direction from the solvent passage 21, but is guided toward the outer peripheral surface 12C by the annular solvent guide 22, and is discharged from the outer peripheral end.

At this time, since the solvent diffusion air ejection hole 9 ejects the solvent diffusion air toward the outer peripheral surface 12C of the bell cup 12, the solvent discharged from the annular solvent guide 22 and the solvent diffused air along the outer peripheral surface 12C. Solvent flowing around the outer peripheral surface 12C
While being pressed against the outer peripheral surface 12C. As a result, the solvent is removed from the outer peripheral surface 1 of the bell cup 12.
Since the entire surface is spread with a uniform film thickness at 2C, the outer peripheral surface 12
Cleaning can be performed without leaving any paint adhered to C.

When the work of cleaning the pre-color paint adhered to each part is completed, the operation proceeds to the paint filling work, where the paint of the next color is supplied to the paint supply path 5 of the feed tube 4 and the like, to prepare for the next paint work.

On the other hand, a description will be given of a cleaning operation for cleaning the outer peripheral surface 12C of the bell cup 12 when the coating operation is continued using the same paint without changing colors. In this case, the solvent is not discharged from the paint supply path 5 of the feed tube 4, but is discharged to the solvent reservoir 18 only from the solvent supply path 6. As a result, the solvent reservoir 21 is connected to the solvent passage 21.
The solvent flowing out through the outer peripheral surface 12C of the bell cup 12 can wash only the paint adhered to the outer peripheral surface 12C.

Thus, according to the present embodiment, the solvent reservoir 18 and the paint reservoir 19 are separately provided by the annular intermediate wall portion 16A of the intermediate cylinder portion 16, and the solvent passage 21 is provided in the solvent reservoir 1
An opening 8 is provided. Therefore, at the time of the painting operation, the paint supplied to the paint pool 19 can be prevented from flowing out to the solvent pool 18 and the solvent passage 21 side. As a result, it is possible to prevent the paint flowing out from the solvent passage 21 from adhering to the outer peripheral surface 12C of the bell cup 12 as in the related art, and it is possible to reduce the cleaning time and the amount of solvent used. In addition, it is possible to prevent the paint that has flowed out to the outer peripheral surface 12C of the bell cup 12 from adhering to the painted surface of the object to be coated, thereby improving the coating quality and improving the reliability.

Since a clean solvent containing no paint can be retained in the solvent reservoir 18, the solvent having a high cleaning ability is supplied from the solvent passage 21 to the bell cup 1.
2 can be supplied to the outer peripheral surface 12C. Therefore, the paint adhered to the outer peripheral surface 12C of the bell cup 12 can be efficiently cleaned, which also shortens the cleaning time,
The amount of solvent used can be reduced.

In the case of performing a coating operation using the same paint without performing color change, if it is necessary to wash the paint adhered to the outer peripheral surface 12 C of the bell cup 12, the solvent is supplied from the solvent supply path 6. The solvent is discharged to 18. Thus, only the outer peripheral surface 12C of the bell cup 12 can be cleaned without cleaning the paint pool 19, the front plate 17, the paint thinning surface 20, and the like, and the amount of solvent used can be minimized. .

Further, on the outer peripheral side of the bell cup 12, an annular solvent guide 22 for guiding the solvent flowing out of the solvent passage 21 toward the outer peripheral surface 12C of the bell cup 12 is provided. The solvent flowing out of the solvent passage 21 and trying to scatter in the radial direction is
Can be guided to the front side toward the outer peripheral surface 12C, and the solvent can be used effectively, and the washing efficiency of the paint can be increased.

Further, since each solvent passage 21 is inclined toward the rear side of the bell cup 12 from the inflow side to the outflow side, the extending direction of each solvent passage 21 is set in the centrifugal direction of the rotary atomizing head 11 ( (Radial direction).
Thus, the solvent supplied to the solvent reservoir 18 can be uniformly flowed out by the resistance due to the inclination without flowing out the solvent supplied to the solvent reservoir 18 at a stretch by centrifugal force. As a result, the paint adhered to the outer peripheral surface 12C of the bell cup 12 can be washed evenly with a small amount of solvent.

On the other hand, on the rear side of the bell cup 12, there is provided a solvent diffusion air ejection hole 9 for blowing solvent diffusion air for diffusing the solvent flowing out of each solvent passage 21, so that the solvent diffusion air is annular. The solvent discharged from the solvent guide 22 and the solvent flowing along the outer peripheral surface 12C are transferred to the outer peripheral surface 12C.
While being pressed against the outer peripheral surface 12C. As a result, the solvent can be spread over the outer peripheral surface 12C of the bell cup 12 with a uniform film thickness, and the coating can be washed without leaving the adhered paint. Thus, an efficient washing operation can be performed with a small amount of the solvent.

FIG. 4 shows a second embodiment of the present invention. This embodiment is characterized in that the bell cup is formed in a cup shape and the annular intermediate wall is provided integrally with the bell cup, so that only the front plate as the front wall is made a separate member. In the present embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 31 denotes a rotary atomizing head according to the present embodiment.
The rotary atomizing head 31 includes a bell cup 32, a solvent reservoir 39, a paint reservoir 40, a paint thinning surface 41, and a solvent passage 4, which will be described later.
2. It is generally constituted by an annular solvent guide 43 and the like.

Reference numeral 32 denotes a bell cup according to the present embodiment.
The bell cup 32 according to the first embodiment differs from the bell cup 32 according to the first embodiment in that the bell cup 32 has a cup shape that expands slightly toward the front side and that an annular intermediate wall 35 described later is integrally provided. Is different. And the bell cup 32
Rear attachment tube 32A and front bell-shaped expansion 32B
The bell-shaped expanding portion 32B is formed by expanding its outer peripheral surface 32C in a cup shape in a small spread forward from the mounting cylinder portion 32A.

Reference numeral 33 denotes an annular rear wall provided on the inner peripheral side of the bell cup 32. The annular rear wall 33 is provided with a mounting cylinder 32A.
It is located on the rear side, which is the boundary portion between the outer tube 4 and the bell-shaped enlarged portion 32B, and projects inward. The central portion thereof is an outer tube insertion hole 33A through which the outer tube 4B of the feed tube 4 is inserted. In addition, an arc surface 34 is provided on the front side of the annular rear wall portion 33 for smoothly flowing the solvent in a solvent reservoir 39 described later.

Reference numeral 35 denotes an annular intermediate wall portion formed at the axially intermediate position of the bell cup 32 at the front side of the arc surface 34 and integrally formed on the inner peripheral side of the bell cup 32. The portion 35 projects inward to separate a solvent reservoir 39 and a paint reservoir 40 described later. The center of the annular intermediate wall portion 35 is the inner tube 4A of the feed tube 4.
Is an inner cylinder insertion hole 35A through which the hole is inserted.

Reference numeral 36 denotes an inclined surface whose diameter is increased from the annular intermediate wall portion 35 toward the front side. Further, reference numeral 37 denotes a mounting step provided on the front side of the inclined surface 36 and opened at the front surface of the bell-shaped enlarged portion 32B. The mounting step 37 positions a front plate 38 described later. is there.

Reference numeral 38 denotes a front plate as a front wall portion attached to the attachment step 37 of the bell cup 32. The front plate 38 has a disk shape, and a conical projection 38A is formed at the center thereof. . Further, the paint outlet holes 3 are provided on the outer peripheral side of the front plate 38.
8B, 38B,..., And a plurality of solvent outflow holes 38C, 38C,.

Here, the annular rear wall portion 33 and the annular intermediate wall portion 3
The front plate 5 and the front plate 38 constituting the front wall part respectively constitute the bell cup 32, and are arranged apart from each other in the axial direction of the bell cup 32.

Reference numeral 39 denotes a solvent reservoir defined between the annular rear wall portion 33 and the annular intermediate wall portion 35 of the bell cup 32. The solvent reservoir 39 is provided separately and separately from a paint reservoir 40 described later. Is formed. Reference numeral 40 denotes a paint reservoir defined separately from the solvent reservoir 39 between the annular intermediate wall portion 35 and the front plate 38.

Reference numeral 41 denotes a paint thinning surface provided from the front plate 38 to the front end of the bell cup 32. The paint thinning surface 41 is formed as an inclined surface whose diameter gradually increases toward the front side. It is the edge 41A.

Reference numeral 42 denotes a plurality of solvent passages (only two are shown) provided in the bell cup 32. Each of the solvent passages 42
The inflow side is open to the solvent reservoir 39 (arc surface 34) and the outflow side is open to the rear of the outer peripheral surface 32C so as to be inclined toward the rear side of the bell cup 32 from the inflow side to the outflow side.

On the other hand, reference numeral 43 denotes an annular solvent guide located at the rear side of the solvent passage 42 and attached to the outer peripheral side of the bell cup 32. The annular solvent guide 43 extends substantially forward to cover the outer peripheral surface 32C. It is formed in a cylindrical shape.

Thus, according to the present embodiment configured as described above, the cup-shaped rotary atomizing head 3 having a small spread is provided.
Even when the coating and cleaning operations are performed by using 1, the amount of solvent used can be reduced, the cleaning time can be reduced, the coating quality can be improved, and the like.

Next, FIG. 5 shows a third embodiment of the present invention. The feature of the present embodiment resides in that the annular intermediate wall portion is provided integrally with the bell cup, and the annular rear wall portion and the front plate forming the front wall portion are formed as separate members from the bell cup. In addition,
In the present embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 51 denotes a rotary atomizing head according to the present embodiment.
The rotary atomizing head 51 includes a bell cup 52, a solvent reservoir 59, a paint reservoir 60, a paint thinning surface 61, and a solvent passage 6, which will be described later.
2. It is generally constituted by an annular solvent guide 63 and the like.

Reference numeral 52 denotes a bell cup according to the present embodiment.
The bell cup 52 is similar to the first embodiment in that an annular intermediate wall portion 55 is provided integrally, and an annular rear wall portion 53 and a front plate 58 forming a front wall portion are provided as separate members. It is different from the bell cup 12. And bell cup 5
2 comprises a rear-side mounting tubular portion 52A and a front-side bell-shaped expanding portion 52B, and the bell-shaped expanding portion 52B
The outer peripheral surface 52C is formed so as to be widened and widened forward in a bell shape.

Reference numeral 53 denotes an annular rear wall provided on the inner peripheral side of the bell cup 52. The annular rear wall 53 is
Is formed as a separate member, and is mounted so as to protrude inward at a rear side serving as a boundary between the mounting cylinder portion 52A and the bell-shaped expansion portion 52B. An arc surface 54 is provided on the front side of the annular rear wall 53.

Reference numeral 55 denotes an annular intermediate wall portion formed at the axially intermediate position of the bell cup 52 at the front side of the arc surface 54 and integrally formed on the inner peripheral side of the bell cup 52. The portion 55 projects inward to separate a later-described solvent reservoir 59 and a paint reservoir 60.

Reference numeral 56 denotes an inclined surface whose diameter is increased from the annular intermediate wall portion 55 toward the front side, and reference numeral 57 denotes a position located in front of the inclined surface 56 and opens at the front surface of the bell-shaped enlarged portion 52B. Each mounting step is shown.

A front plate 58 is provided as a separate member from the bell cup 52 and is attached to the attachment step 57 as a front wall. The front plate 58 has a disk shape and has a conical projection at the center. 58A are formed. Are provided on the outer peripheral side of the front plate 58, and a plurality of solvent outflow holes 58C, 58C are provided at the center (only two are shown). Have been.

Here, the annular rear wall portion 53 and the annular intermediate wall portion 5
The front plate 5 and the front plate 58 constituting the front wall constitute the bell cup 52, respectively, and are arranged apart from each other in the axial direction of the bell cup 52.

Reference numeral 59 denotes a solvent reservoir defined between the annular rear wall portion 53 and the annular intermediate wall portion 55 of the bell cup 52, and 60 denotes a solvent reservoir between the annular intermediate wall portion 55 and the front plate 58. Figure 2 shows a separately defined paint pool. Reference numeral 61 denotes a paint thinning surface provided from the front plate 58 to the front end of the bell cup 52.

Reference numeral 62 denotes a plurality of solvent passages (only two are shown) provided in the bell cup 52. Each of the solvent passages 62
The inflow side is open to the solvent reservoir 59 (arc surface 54), and the outflow side is open to the rear of the outer peripheral surface 52C so as to incline toward the rear side of the bell cup 52 from the inflow side to the outflow side.

On the other hand, reference numeral 63 denotes an annular solvent guide which is located at the rear side of the solvent passage 62 and which is attached to the outer peripheral side of the bell cup 52 and is made of a separate member.

Thus, according to the present embodiment configured as described above, since the annular rear wall portion 53 is provided as a separate member from the bell cup 52, the degree of freedom in designing can be improved.

In the first embodiment, the solvent passage 2
1 is a bell cup 1 from the inflow side to the outflow side.
2 exemplifies the case where it is inclined to the rear side, but the present invention is not limited to this. For example, the solvent passage 21 may be formed straight in the radial direction or may be formed to be inclined to the front side. Is also good. This configuration can be similarly applied to the second and third embodiments.

In each embodiment, the feed tube 4 as a nozzle is formed in a double cylindrical shape by an inner cylinder 4A and an outer cylinder 4B which are arranged coaxially. Although the description has been made assuming that the solvent supply path 6 is provided between the inner cylinder 4A and the outer cylinder 4B, the present invention is not limited to this. For example, a configuration may be adopted in which a paint supply pipe and a solvent supply pipe are provided in parallel. .

Further, in each embodiment, the air motor 2
Although the description has been given of the case where the rotary shaft 3 is rotationally driven by using the example, the present invention is not limited to this, and the rotary shaft may be rotationally driven using, for example, an electric motor or the like.

[0095]

As described in detail above, according to the first aspect of the present invention, the inner peripheral side of the bell cup has an annular rear wall portion located on the rear side, an annular intermediate wall portion located in the middle, and a front side. A front wall portion having a plurality of paint outlet holes is provided in the axial direction and is spaced apart from the front wall portion having a plurality of paint outlet holes, and a solvent for collecting the solvent discharged from the nozzle is provided between the annular rear wall portion and the annular intermediate wall portion of the bell cup A reservoir is provided, and a paint reservoir is provided between the annular intermediate wall portion and the front wall portion of the bell cup, which is separately formed from the solvent reservoir, and stores a paint discharged from a nozzle. A plurality of solvent passages are provided which are open to the solvent reservoir and whose outlet side is open to the outer peripheral surface of the bell cup.

Therefore, when the paint and the solvent are discharged from the nozzle into the paint reservoir to perform the painting operation and the inner peripheral surface cleaning operation, the paint reservoir is provided separately from the solvent reservoir by the annular intermediate wall portion. It is possible to prevent the paint and the contaminated solvent in the paint reservoir from remaining in the solvent, flowing out to the solvent passage side, and adhering to the outer peripheral surface of the bell cup, etc., and reducing the cleaning time and the amount of solvent used. In addition, it is possible to prevent the paint flowing out on the outer peripheral surface of the bell cup from adhering to the painted surface of the object to be coated, thereby improving the coating quality and improving the reliability.

When the cleaning solvent is discharged from the nozzle into the solvent reservoir to perform the outer peripheral surface cleaning work, the outer peripheral surface of the bell cup is cleaned with a solvent having a high cleaning ability without being mixed with the cleaned paint. Thus, the cleaning time and the amount of solvent used for cleaning the outer peripheral surface of the bell cup can be reduced.

Further, in the case of performing a painting operation using the same paint without performing color change, if it is necessary to wash the paint adhered to the outer peripheral surface of the bell cup, the solvent is discharged from the nozzle only to the solvent pool. I do. Thereby, only the paint adhered to the outer peripheral surface of the bell cup can be washed, and the amount of the solvent used can be minimized.

According to the second aspect of the present invention, the annular solvent guide is provided on the outer peripheral side of the bell cup to guide the solvent flowing out of each solvent passage toward the outer peripheral surface of the bell cup. Since the guide can guide the solvent flowing out of each solvent passage and trying to scatter in the radial direction toward the outer peripheral surface of the bell cup, the paint adhered to the outer peripheral surface of the bell cup with a small amount of solvent. Can be efficiently washed.

According to the third aspect of the present invention, each solvent passage is
Since the configuration is such that the bell cup is inclined rearward from the inflow side to the outflow side, the extending direction of each solvent passage can be different from the centrifugal direction (radial direction) of the rotary atomizing head. As a result, the solvent supplied from the solvent reservoir does not flow out at once by centrifugal force, but the solvent flows out uniformly by using the resistance due to the inclination, so that a small amount of solvent adheres to the outer peripheral surface of the bell cup. Paints can be washed evenly.

According to the fourth aspect of the present invention, the solvent flowing out of each solvent passage is diffused by blowing the solvent diffusion air from the rear side of the bell cup toward the outer peripheral surface of the bell cup. The solvent diffusion air spreads the solvent flowing out of each of the solvent passages on the outer peripheral surface of the bell cup while pressing the solvent against the outer peripheral surface of the bell cup. As a result, the solvent spreads over the entire outer peripheral surface, so that the solvent can be washed without leaving any attached paint, and an efficient washing operation can be performed with a small amount of the solvent.

[Brief description of the drawings]

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

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

FIG. 3 is a longitudinal sectional view showing the rotary atomizing head alone.

FIG. 4 is a longitudinal sectional view showing a rotary atomizing head according to a second embodiment of the present invention by itself.

FIG. 5 is a longitudinal sectional view showing a rotary atomizing head according to a third embodiment of the present invention by itself.

[Explanation of symbols]

 4 Feed tube (nozzle) 9 Solvent diffusion air ejection hole 11, 31, 51 Rotary atomizing head 12, 32, 52 Bell cup 12C, 32C, 52C Outer peripheral surface 13, 33, 53 Annular rear wall portion 16 Intermediate cylindrical portion 16A, 35,55 Annular intermediate wall portion 17,38,58 Front plate (front wall portion) 17B, 38B, 58B Paint outlet 18,39,59 Solvent reservoir 19,40,60 Paint reservoir 20,41,61 Paint thinning surface 21, 42, 62 Solvent passage 22, 43, 63 Annular solvent guide

Claims (4)

[Claims] 1. A front side which is formed in a bell shape or a cup shape and has an annular rear wall portion located on a rear side on the inner peripheral side, an annular intermediate wall portion located at an intermediate position and a plurality of paint outlet holes located on a front side. A bell cup provided with a wall portion spaced apart in the axial direction, a solvent reservoir defined between an annular rear wall portion and an annular intermediate wall portion of the bell cup, and for storing a solvent discharged from a nozzle; A paint reservoir that is defined separately from the solvent reservoir between the annular intermediate wall portion and the front wall portion of the bell cup, and that stores the paint discharged from the nozzle; A paint thinning surface that is provided over the front end and thins the paint that has flowed out of the paint reservoir through the paint outflow hole; an inflow side that opens to the solvent reservoir; And a plurality of solvent passages The rotary atomizing head. 2. The rotary atomizer according to claim 1, wherein an annular solvent guide is provided on an outer peripheral side of the bell cup to guide a solvent flowing out of each of the solvent passages toward an outer peripheral surface of the bell cup. Head. 3. The rotary atomizing head according to claim 1, wherein each of the solvent passages is inclined toward the rear side of the bell cup from the inflow side to the outflow side. 4. A configuration in which the solvent flowing out of each of the solvent passages is diffused on the outer peripheral surface by blowing solvent diffusion air from the rear side of the bell cup toward the outer peripheral surface of the bell cup. , 2 or 3.