JP4347036B2 - Rotary atomization coating equipment - Google Patents

Description

  The present invention relates to a technology of a rotary atomizing coating apparatus that sprays and paints a mist-like paint on an object to be coated such as an automobile body.

2. Description of the Related Art Conventionally, a rotary rotating shaft, a bell-shaped rotating atomizing head provided at the tip of the rotating shaft, and a paint supply pipe that passes through the rotating shaft and supplies paint to the rotating atomizing head are provided. Technology of a rotary atomizing coating device that applies a centrifugal force to the paint by the rotation of the atomizing head to make it into a mist, and sprays the mist on the object to be coated (for example, the body of an automobile or the housing of a home appliance). Is known.
Such a rotary atomizing coating apparatus is roughly divided into (1) a rotary atomizing coating apparatus having a single supply pipe and (2) a rotary atomizing coating apparatus having a plurality of paint supply pipes. Is done.

  (1) A rotary atomizing coating apparatus including a single paint supply pipe is mainly used for spraying one type of paint with a single rotary atomizing coating apparatus. In addition, by washing the part to which the paint used so far (the paint supply path including the paint supply pipe and the rotary atomizing head) with a solvent is used, it is possible to switch between multiple types of paints for spray painting. A rotary atomizing coating apparatus having a simple structure is also known.

On the other hand, (2) a rotary atomizing coating apparatus including a plurality of paint supply pipes is mainly used for spray coating by switching a plurality of types of paints with one rotary atomizing coating apparatus.
Such a rotary atomizing coating apparatus is provided with a dedicated paint supply pipe for each paint, thereby eliminating the work of cleaning the paint supply path including the paint supply pipe when switching the paint to be spray-coated. It aims to reduce loss, shorten cleaning time (in other words, paint switching time), and reduce the amount of solvent required for cleaning. For example, as described in Patent Document 1.

JP-A-9-75789

  When spray coating with multiple types of paints switched with a single rotary atomizing coating device, along with "improving paint switching work efficiency (reducing paint loss, reducing cleaning time, and reducing the amount of solvent required for cleaning)" An important technical issue is “preventing mixing of different paints”.

From the viewpoint of "preventing mixing of different paints", (2) the rotary atomizing coating device with multiple paint supply pipes does not need to clean the paint supply path including the paint supply pipes. There is a fundamental problem that the paint always stays in the paint supply pipe which is not applied, the paint drops from the paint supply pipe to the rotary atomizing head, and different paints are mixed during spray coating. .
Therefore, (2) the rotary atomizing coating apparatus having a plurality of coating material supply pipes is difficult to apply to applications that must absolutely avoid mixing different coating materials.

Further, in any case of (1) a rotary atomizing coating apparatus having a single paint supply pipe and (2) a rotary atomizing coating apparatus having a plurality of paint supply pipes, it adheres to the rotary atomizing head. It is not easy to sufficiently wash the paint so that mixing does not occur.
In particular, in the rotary atomizing head, when the paint adheres to a site near the front end of the paint supply pipe, it is difficult to allow the solvent to reach the site and clean it.

As one method for solving such a problem, as shown in FIG. 7, a single paint supply pipe 105 is a double pipe comprising an inner pipe 105a and an outer pipe 105b, and the inner pipe 105a passes paint or solvent. It has been proposed that the cleaning effect of the rotary atomizing head is improved by allowing the solvent to pass through the portion sandwiched between the outer tube 105b and the inner tube 105a.
However, even in such a configuration, when the paint adheres to a portion around the front end portion of the paint supply pipe on the inner wall surface of the rotary atomizing head, the portion is not sufficiently cleaned.
Therefore, in order to obtain a sufficient cleaning effect, the solvent has to be flowed for a long time and at an excessive flow rate, and problems such as an increase in cleaning time and an increase in the amount of solvent required for cleaning have occurred.

  In view of the above situation, the present invention sufficiently removes the paint adhering to the rotary atomizing head by washing to prevent mixing of different paints, and shortens the washing time and the amount of solvent required for washing. A rotary atomizing coating apparatus is provided.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in claim 1 , a hollow rotary shaft, a rotary atomizing head provided at the tip of the rotary shaft, a paint supply pipe for supplying paint or a solvent to the rotary atomizing head through the rotary shaft, In a rotary atomizing coating apparatus comprising:
The front end portion of the paint supply pipe is formed in a trumpet shape, and a paint reservoir portion recessed backward is formed on the inner wall surface of the rotary atomizing head on the periphery of the front end portion of the paint supply pipe. In the axial direction of the shaft, the front end portion of the paint supply pipe and the front end portion of the paint reservoir portion are substantially matched.

In claim 2 , a paint reservoir portion recessed rearward is formed on the inner wall surface of the rotary atomizing head at a portion around the front end portion of the paint supply pipe, and is formed in the middle portion of the inner wall surface of the rotary atomizing head. In the blocking member that is arranged and applies centrifugal force to the coating material, a concave portion that is recessed forward is formed at a portion facing the coating material reservoir.

  As effects of the present invention, the following effects can be obtained.

According to the first aspect of the present invention, it is possible to make the solvent reach the space facing the portion around the front end portion of the coating material supply pipe on the inner wall surface of the rotary atomizing head, so that the solvent can be sufficiently washed. Therefore, it is possible to prevent mixing of different paints. In addition, the solvent can reach the part where the paint is adhered without excessively increasing the flow rate of the solvent, so the cleaning time can be shortened and the amount of solvent required for the cleaning operation can be reduced. is there.
In particular, the front end of the paint supply pipe is formed in a trumpet shape, and the front end of the paint supply pipe and the front end of the paint reservoir are substantially coincided with each other. The effect of making negative pressure in the space facing the front end of the paint supply pipe on the inner wall is improved, and the cleaning effect (can be cleaned without any defects, shortening the time required for cleaning, the amount of solvent required for cleaning) Effect).

According to the second aspect of the present invention, a strong vortex-like air current is generated in a space for applying a centrifugal force to the paint at the rotary atomizing head, thereby forming a periphery of the front end portion of the paint supply pipe on the inner wall surface of the rotary atomizing head. It is possible to allow the solvent to reach the site and thoroughly wash it. Therefore, it is possible to prevent mixing of different paints. In addition, the solvent can reach the part where the paint is adhered without excessively increasing the flow rate of the solvent, so the cleaning time can be shortened and the amount of solvent required for the cleaning operation can be reduced. is there.

  Below, the whole structure of the rotary atomization coating apparatus 1 which concerns on one Example of this invention using FIG.1, FIG.2 and FIG.6 is demonstrated.

In the following description, the rotary atomizing coating apparatus 1 including the paint supply pipe 5 composed of a single pipe is described. However, the paint supply pipe is a double pipe composed of an inner pipe and an outer pipe, and Can be applied to a rotary atomizing coating apparatus having a configuration in which paint and solvent can be discharged and solvent can be discharged from the gap between the inner tube and the outer tube.
Further, the number of paint supply pipes is not limited to one, and the present invention can also be applied to a rotary atomizing coating apparatus in which a plurality of paint supply pipes are provided on a hollow rotating shaft.
Furthermore, the present invention can also be applied to the rotary atomizing coating apparatus in which a member having a single or a plurality of paint supply paths is inserted through a hollow rotating shaft.

The rotary atomizing coating apparatus of the present invention can be widely applied when using an oil-based paint, a water-based paint, or other paints. Therefore, in the following description, the solvent in the case of an oil-based paint refers to an organic solvent such as thinner, and the solvent in the case of an aqueous paint refers to water.
Furthermore, in the following description, the direction of arrow A in FIG. Here, the arrow A is substantially parallel to the axial direction of the rotating shaft 4 described later.

  The rotary atomizing coating apparatus 1 sprays a mist-like paint onto an object to be coated (for example, a car body or a housing of a home appliance), for example, (B) in FIG. ) And FIG. 6C, it is used in a state of being fixedly attached to the tip of the articulated robot 101, the upper part of the gate-shaped support 102, or the middle of the support 103.

  As shown in FIG. 1, the rotary atomizing coating apparatus 1 is mainly composed of a main body 2, a motor 3, a rotating shaft 4, a paint supply pipe 5, a rotating atomizing head 6, and the like.

  The main body 2 is a member constituting the structure of the rotary atomizing coating apparatus 1 and accommodates the motor 3. The main body 2 also functions as a support member for fixing and supporting the rotary atomizing coating apparatus 1 to an articulated robot, a support or the like. The outer peripheral surface of the main body 2 is covered with a cover 10 that is a substantially cylindrical member. The main body 2 also houses a high voltage generator (not shown) for charging the mist paint sprayed from the rotary atomizing head 6.

The motor 3 rotates the rotary shaft 4. In the case of the present embodiment, the motor 3 is a pneumatic motor, and includes a body portion 30, an air bearing 31, and the like.
The body portion 30 is a member that forms the structure of the motor 3, and rotatably supports the rotary shaft 4 via an air bearing 31. Air is supplied to the air bearing 31 from an air supply path 31a.

The rotating shaft 4 is a member that transmits the rotational driving force of the motor 3 to the rotary atomizing head 6 and is a hollow (substantially cylindrical) member. A male screw is formed on the front end portion (tip portion) of the outer peripheral surface of the rotating shaft 4, and a female screw is formed on the inner peripheral surface of the base portion 60, so that the rotary atomizing head 6 is screwed onto the tip portion of the rotating shaft 4. Established.
The turbine 40 is a blade formed at the rear end (base) of the rotary shaft 4, and rotates the rotary shaft 4 with air fed from a compressor (not shown). In addition, a paint supply pipe 5 is provided on the rotary shaft 4 so as to be relatively rotatable.
In the present embodiment, the turbine 40 is formed at the rear end portion of the rotary shaft 4, but may be externally fitted and fixed to the rotary shaft 4 as a separate member. In this embodiment, the rotary shaft 4 is rotated by the pneumatic motor 3. However, the present invention is not limited to this, and the rotary shaft 4 may be rotated by a hydraulic or electric motor.

As shown in FIGS. 1 and 2, the coating material supply pipe 5 supplies the coating material to the rotary atomizing head 6 (more precisely, the inner wall surface of the rotary atomizing head 6). In the present embodiment, the coating material supply pipe 5 is a single pipe and also serves as a function of supplying a solvent for cleaning the coating material adhering to the rotary atomizing head 6.
The paint supply pipe 5 is a tubular member, and a supply path 50 through which the paint or solvent passes is formed, and a nozzle part 51 is formed at the front end (front end). The shape of the nozzle portion 51 is a trumpet shape (a divergent shape) whose diameter increases toward the front.
A valve seat 52 is formed at the rear end portion of the paint supply pipe 5 and is fitted and fixed to the distal end portion (front end portion) of the connection pipe 11 which is a tubular member. The rear end portion of the connecting pipe 11 is fixed to the main body 2.

The needle valve 12 is a rod-like member, and penetrates the connecting pipe 11 while maintaining a predetermined gap with the inner wall of the connecting pipe 11. The distal end portion (front end portion) of the needle valve 12 is formed in a needle shape and can be seated on the valve seat 52. A piston 12 a is formed at the base (rear end) of the needle valve 12, and the tip of the needle valve 12 is biased by the spring 13 in the direction in which the needle valve 12 is seated on the valve seat 52.
The space on the front side of the piston 12a communicates with the air supply path 14, and the needle valve 12 is moved backward against the urging force of the spring 13 by supplying compressed air to the space. The tip portion and the valve seat 52 can be separated from each other.
A fluid supply path 15 formed in the main body 2 includes a container (not shown) for storing a plurality of types of paints for each paint and a paint switching device (not shown) for switching paints or solvents supplied to the rotary atomizing head 6. ) And the paint supply pipe 5 (more precisely, the rear end portion of the communication pipe 11).

As described above, by operating (moving back and forth) the needle valve 12, the fluid supply path 15 and the paint supply pipe 5 are communicated or cut off, and the paint or solvent is supplied or supplied to the rotary atomizing head 6. Stop.
The operation of the paint switching device, the on / off of the motor 3, the adjustment of the rotation speed of the motor 3, the operation of the needle valve 12, etc. are performed by a control device (not shown).

  As shown in FIGS. 1 and 2, the rotary atomizing head 6 rotates integrally with the rotary shaft 4 to apply centrifugal force to the paint supplied to the surface of the rotary atomizing head 6 to form a mist. It sprays on things. The rotary atomizing head 6 is mainly composed of a base 60, an enlarged diameter portion 61, a partition wall 62, a closing member 65, and the like.

  The base 60 is a member constituting the latter half of the rotary atomizing head 6 and is formed in a substantially cylindrical shape. On the inner peripheral surface of the base 60, a female screw for being screwed to the rotary shaft 4 is formed.

The enlarged diameter portion 61 is a member constituting the front half of the rotary atomizing head 6, and the shape thereof is a trumpet shape whose diameter is increased toward the front. A partition wall 62 is provided at a boundary portion between the enlarged diameter portion 61 and the base portion 60, and a through hole 63 is formed at a substantially central portion of the partition wall 62. On the inner wall surface 61 a of the enlarged diameter portion 61, the paint reservoir portion 64 that is recessed rearward at the peripheral portion of the through-hole 63 (in other words, the portion around the nozzle portion 51 that is the front end portion of the paint supply pipe 5). Is formed.
At this time, the tip end portion (front end portion) of the nozzle portion 51 of the paint supply pipe 5 inserted into the through hole 63 and the front end portion 64a (see FIG. 3) on the center side of the paint reservoir portion 64 are connected to the rotating shaft 4. In the axial direction (a direction substantially parallel to the arrow A) (which is substantially flush).

A substantially disc-shaped blocking member 65 is disposed in the middle of the inner wall surface 61 a of the enlarged diameter portion 61, and an atomization chamber 66 is formed. The atomizing chamber 66 is a space for applying a centrifugal force to the paint in the rotary atomizing head 6, and is surrounded by the rear part (back part) of the inner wall surface 61 a of the enlarged diameter part 61 and the closing member 65, and the paint or the solvent It is supplied to the atomization chamber 66 by the paint supply pipe 6.
The closing member 65 applies centrifugal force to the coating material supplied to the atomizing chamber 66 to separate (atomize) the coating material into fine particles. A substantially conical projection 65a is formed at the center of the inner surface of the closing member 65 (the surface facing the atomization chamber 66), and a recess 65b recessed forward is formed at the peripheral portion of the projection 65a. Is formed.
Further, the closing member 65 is formed with a central communication hole 65c that communicates the middle portion of the protrusion 65a and the central portion of the outer surface of the closing member 65 (the surface not facing the atomization chamber 66). A plurality of outer edge portion communication holes 65d, 65d,... Are formed along the inner wall surface 61a of the diameter portion 61 to communicate the inside and the outside of the atomization chamber 66.

Below, the flow of the coating material in the coating operation of the rotary atomizing coating apparatus 1 is demonstrated using FIG.
The paint passes through the supply path 50 of the paint supply pipe 5, is discharged from the nozzle portion 51, and is supplied to the atomization chamber 66. Most of the paint discharged from the nozzle portion 51 travels straight forward in a converged state, and collides with a protrusion 65 a formed on the inner surface of the closing member 65. Since the rotary atomizing head 6 rotates at high speed during the painting operation, a centrifugal force acts on the paint colliding with the protrusion 65 a, and the paint follows the outer edge of the closing member 65 along the inner surface of the closing member 65. Move towards the department.
The coating material that has reached the outer edge of the blocking member 65 passes through the outer edge communication holes 65d, 65d,..., Moves to the outside of the atomizing chamber 66, and further, along the inner wall surface 61a, the front end of the enlarged diameter portion 61. Move towards (outer edge). At this time, the centrifugal force acting on the paint increases as it approaches the front end portion (outer edge portion) of the diameter-expanded portion 61, so that the paint is separated into a large number of fine droplets to form a mist. The mist-like paint scatters from the front end portion (outer edge portion) of the enlarged diameter portion 61 and adheres to the surface of the object to be coated.
As described above, the rotary atomizing coating apparatus 1 sprays an object to be coated.

Here, since the rotary atomizing head 6 rotates at high speed during the painting operation, the portion constituting the inner wall surface of the atomizing chamber 66 other than the portion where the paint flows (in the case of the present embodiment, the paint reservoir 64). In addition, the paint adheres to the outer surface of the closing member 65.
Therefore, in order to prevent mixing of different types of paints, the solvent can reach these parts during cleaning work (parts other than the part where the normal paint flows during painting work), and the paint adhered to the parts. Need to be dissolved and removed.

  Below, the flow of the solvent in the washing | cleaning operation | work of the rotary atomization coating apparatus 1 is demonstrated using FIG. The cleaning work is performed when the paint used in the rotary atomizing coating apparatus 1 is replaced with a different kind of paint or when the paint work is stopped for a while.

The solvent passes through the supply path 50 of the paint supply pipe 5, is discharged from the nozzle portion 51, and is supplied to the atomization chamber 66. Most of the solvent discharged from the nozzle portion 51 travels straight forward in a converged state, and collides with a protrusion 65 a formed on the inner surface of the closing member 65. The rotary atomizing head 6 is still rotating during the cleaning operation (however, the paint adhering to the area around the front end portion (nozzle portion 51) of the paint supply pipe 5 on the inner wall surface 61a of the rotary atomizing head 6) Therefore, the centrifugal force acts on the solvent that has collided with the protrusion 65 a, and the solvent acts on the blocking member 65 along the inner surface of the blocking member 65. Move towards the outer edge of the.
The solvent that has reached the outer edge of the blocking member 65 passes through the outer edge communication holes 65d, 65d,..., Moves to the outside of the atomizing chamber 66, and further, along the inner wall surface 61a, the front end of the enlarged diameter portion 61. Move towards (outer edge).
In this way, the solvent flows through substantially the same part as the part through which the paint normally flows during the painting operation, and it is possible to dissolve and remove the paint adhering to the part.

Further, a part of the solvent colliding with the protrusion 65a passes through the central communication hole 65c and reaches the central portion of the outer surface of the closing member 65, and then along the outer surface of the closing member 65 by centrifugal force. It moves to the outer edge of the closing member 65.
In this way, the solvent can flow on the outer surface of the closing member 65 to which the paint has adhered during the painting operation, and the paint adhering to the site can be dissolved and removed.

The rotary atomizing coating apparatus 1 of the present embodiment forms a front end portion (nozzle portion 51) of the coating material supply pipe 5 in a trumpet shape and mixes the solvent and compressed air (or the solvent and compressed air). By alternately supplying these to the atomization chamber 66, the cleaning effect of the portion constituting the inner wall surface of the atomization chamber 66 other than the portion where the paint flows (in the case of the present embodiment, the paint reservoir 64) is obtained. It is increasing.
That is, the compressed air supplied to the atomization chamber 66 together with the solvent does not go straight in a state where most of the compressed air is converged because the nozzle portion 51 is enlarged in a trumpet shape, but has a substantially conical shape. It is ejected forward from the nozzle part 51 with a certain extent. Then, due to the flow of the compressed air, the space near the front end portion (nozzle portion 51) of the coating material supply pipe 5 on the inner wall surface 61a of the rotary atomizing head 6, that is, the surface of the coating material pool portion 64 is faced. The space to do becomes negative pressure. At this time, the gap between the end face of the through-hole 63 of the rotary atomizing head 6 and the front end portion of the paint supply pipe 5 also becomes negative pressure.

As a result, the solvent is attracted to the space where the negative pressure is reached, and a part of the solvent can easily reach the paint reservoir 64. On the wall surface 61a, it is possible to sufficiently clean the portion (in the present embodiment, the paint reservoir 64) that is the periphery of the front end portion (nozzle portion 51) of the paint supply pipe 5. Further, it is possible to sufficiently clean the gap where the end face of the through hole 63 of the rotary atomizing head 6 and the front end portion of the paint supply pipe 5 face each other. Therefore, it is possible to prevent mixing of different paints.
In addition, it is possible to reduce the cleaning time and the amount of solvent required for the cleaning work because the solvent can reach the part where the paint is adhered without excessively increasing the flow rate of the solvent. .

  In addition, about the opening condition (angle (theta) in FIG. 5) of the nozzle part 51, the kind (property) of the coating material used with a rotary atomization coating apparatus, the flow volume (spraying amount) of a coating material, and the shape and magnitude | size of a rotary atomization head What is necessary is just to select suitably according to etc.

Further, the rotary atomizing coating apparatus 1 according to the present embodiment has a paint reservoir that is recessed rearward at a portion that is the periphery of the front end portion (nozzle portion 51) of the paint supply pipe 5 on the inner wall surface 61 a of the rotary atomizing head 6. Part 64 is formed, and the front end part (front end part) of the nozzle part 51 of the paint supply pipe 5 and the front end part 64a (see FIG. 3) on the center side of the paint reservoir part 64 are arranged in the axial direction of the rotary shaft 4 (see FIG. By making it substantially coincide (substantially flush) in the direction substantially parallel to the arrow A), the portion constituting the inner wall surface of the atomizing chamber 66 other than the portion where the paint flows (in the case of this embodiment, the paint reservoir) The cleaning effect of the part 64) is enhanced.
That is, when supplying the compressed air together with the solvent from the paint supply pipe 5 to the atomization chamber 66, the front end part (front end part) of the nozzle part 51 of the paint supply pipe 5 and the front end part 64 a on the center side of the paint reservoir part 64. (Refer to FIG. 3) is substantially coincided with the axial direction of the rotary shaft 4 (direction substantially parallel to the arrow A), the flow of the compressed air causes the flow on the inner wall surface 61a of the rotary atomizing head 6. The space in the vicinity of the portion that is the periphery of the front end portion (nozzle portion 51) of the paint supply pipe 5, that is, the space facing the paint reservoir 64 is negative pressure. At this time, the gap between the end face of the through-hole 63 of the rotary atomizing head 6 and the front end portion of the paint supply pipe 5 also becomes negative pressure.

As a result, the solvent is attracted to the space where the negative pressure is reached, and a part of the solvent can easily reach the paint reservoir 64. On the wall surface 61a, it is possible to sufficiently clean the portion (in the present embodiment, the paint reservoir 64) that is the periphery of the front end portion (nozzle portion 51) of the paint supply pipe 5. Further, it is possible to sufficiently clean the gap where the end face of the through hole 63 of the rotary atomizing head 6 and the front end portion of the paint supply pipe 5 face each other. Therefore, it is possible to prevent mixing of different paints.
In addition, it is possible to reduce the cleaning time and the amount of solvent required for the cleaning work because the solvent can reach the part where the paint is adhered without excessively increasing the flow rate of the solvent. .

From the viewpoint of enhancing the cleaning effect of the paint reservoir 64, the nozzle 51 that is the front end of the paint supply pipe 5 and the paint reservoir 64 in the axial direction of the rotating shaft 4 (direction of arrow A). It is effective to substantially match the front end portion 64a.
This is because, when the nozzle portion 51, which is the front end portion of the paint supply pipe 5, is arranged in front of the front end portion 64 a of the paint reservoir portion 64, the nozzle portion 51 is far from the paint reservoir portion 64 and becomes the paint reservoir portion 64. This is because the effect of making the space facing the negative pressure negative is reduced.
In addition, when the nozzle portion 51 that is the front end portion of the paint supply pipe 5 is disposed behind the front end portion 64a of the paint reservoir portion 64, the nozzle portion 51 is formed even if the nozzle portion 51 is formed in a trumpet shape. This is because the compressed air ejected from the air travels straight forward along the end face of the through-hole 63, so that the effect of making the space facing the paint reservoir 64 negative is small.

In particular, the front end part (nozzle part 51) of the paint supply pipe 5 is formed in a trumpet shape, and the front end part (nozzle part 51) of the paint supply pipe 5 and the front end part 64a of the paint reservoir part 64 are substantially matched. Are simultaneously performed on the inner wall surface 61a of the rotary atomizing head 6 in a space facing the portion (that is, the paint reservoir 64) that is the periphery of the front end (nozzle part 51) of the paint supply pipe 5. It is suitable for further improving the negative pressure effect and has the highest cleaning effect.
Accordingly, the front end part (nozzle part 51) of the paint supply pipe 5 is formed in a trumpet shape, and the front end part (nozzle part 51) of the paint supply pipe 5 and the front end part 64a of the paint reservoir part 64 are substantially matched. The structure of the atomizing head 6 is the most preferable form as an embodiment of the rotary atomizing coating apparatus 1 of the present invention.

  Further, as shown in FIG. 8, the paint supply pipe 55 is a double pipe comprising an inner pipe 55a and an outer pipe 55b, and paint and solvent can be discharged from the inner pipe 55a, and the gap between the inner pipe 55a and the outer pipe 55b. When the solvent can be discharged from the front end portion of the outer tube 55a and the front end portion 64a on the center side of the paint reservoir 64, the axial direction of the rotating shaft 4 (direction substantially parallel to the arrow A) By making them substantially coincide with each other (substantially flush with each other), the space facing the paint reservoir 64 can be set to a negative pressure, and the cleaning effect by the solvent can be enhanced.

Furthermore, the rotary atomizing coating apparatus 1 according to the present embodiment has a paint reservoir that is recessed rearward at a portion that is around the front end portion (nozzle portion 51) of the paint supply pipe 5 on the inner wall surface 61 a of the rotary atomizing head 6. A recess 65b that is recessed forward is formed in a portion facing the paint reservoir 64 in a blocking member 65 that forms a part 64 and is disposed in the middle of the inner wall surface 61a of the rotary atomizing head 6 and applies centrifugal force to the paint. By forming, the cleaning effect of the part (in the case of a present Example, paint reservoir part 64) which comprises the inner wall face of the atomization chamber 66 other than the site | part through which the said paint flows is heightened.
That is, a part of the compressed air that is supplied to the atomization chamber 66 together with the solvent and moves along the inner surface of the closing member 65 is not discharged to the outside from the outer edge communication holes 65d, 65d. The nozzle portion 51 → the inner surface of the closing member 65 (protrusion 65a → recess 65b) → the paint reservoir 64 → nozzle portion 51 →... generate. Due to the generation of the spiral airflow, a part of the solvent can easily reach the paint reservoir 64 together with the airflow, and the inner wall surface 61a of the rotary atomizing head 6 is difficult to clean in the past. It is possible to sufficiently clean the portion (in the case of the present embodiment, the paint reservoir 64) that is the periphery of the front end portion (nozzle portion 51) of the paint supply pipe 5 above. Therefore, it is possible to prevent mixing of different paints.
In addition, it is possible to reduce the cleaning time and the amount of solvent required for the cleaning work because the solvent can reach the part where the paint is adhered without excessively increasing the flow rate of the solvent. .

  In the present embodiment, the number of paint supply pipes 5 penetrating the rotating shaft 4 is one, but the present invention is not limited to this, and the number of paint supply pipes penetrating the rotating shaft is plural. Even in this case, by forming the front end of the paint supply pipe in a trumpet shape, the rotary atomizing head is thoroughly washed to prevent mixing of different paints, and the washing time is shortened and the amount of solvent required for washing Can be reduced.

Further, as shown in FIG. 7, in the case of the conventional rotary atomizing coating apparatus in which the front end portion of the paint supply pipe 105 is not formed in a trumpet shape, the front end (direction of arrow A) of the rotary atomizing coating apparatus is Since the paint reaches the motor along the outer wall of the paint supply pipe and causes failure, the rotary atomizing coating device has its front end (in the direction of arrow A) slightly above the horizontal direction ( More strictly, it can be tilted up to about 10 degrees), and in many cases, it is used downward or obliquely downward.
However, like the rotary atomizing coating apparatus 1 of the present invention, the nozzle portion 51 which is the front end portion of the paint supply pipe 5 is formed in a trumpet shape, so that the outer edge portion of the nozzle portion 51 and the end face (inner circumference) of the through hole 63 are formed. It is possible to reduce the distance to the motor surface 3) and prevent the paint from reaching the motor 3 along the outer wall of the paint supply pipe 5.
Therefore, the rotary atomizing coating apparatus 1 can be used while being tilted upward. In the case of the present embodiment, even when the rotary atomizing coating apparatus 1 is tilted upward by about 30 degrees from the horizontal direction, it is an experiment that the paint does not reach the motor 3 along the outer wall of the paint supply pipe 5. Confirmed by
This is particularly the case when the paint is likely to drip along the outer wall of the paint supply pipe 5, such as when the paint is intermittently sprayed to save the amount of paint used, such as painting the edge of the object. It is valid. Further, it is also effective when a rotary atomizing coating apparatus is used at a low position, such as for painting a bumper for automobiles.

Side surface sectional drawing of the rotary atomization coating apparatus which concerns on one Example of this invention. Side surface sectional drawing of the front-end | tip part of the rotary atomization coating apparatus which concerns on one Example of this invention. Side surface sectional drawing which shows the flow of the coating material at the time of a painting operation. Side surface sectional drawing which shows the flow of the solvent at the time of a cleaning operation. Side surface sectional drawing which shows the front-end part of a coating material supply pipe | tube. The schematic diagram which shows the use condition of the rotary atomization coating apparatus which concerns on one Example of this invention. Side surface sectional drawing of the conventional coating material supply pipe | tube. Side surface sectional drawing of the rotary atomization coating apparatus of this invention which comprises another Example of a coating material supply pipe | tube.

DESCRIPTION OF SYMBOLS 1 Rotating atomization coating apparatus 4 Rotating shaft 5 Paint supply pipe 6 Rotating atomizing head 51 Nozzle part (front end part)

Claims (2)

A rotary atomizing coating apparatus comprising: a hollow rotary shaft; a rotary atomizing head provided at a tip of the rotary shaft; and a paint supply pipe that passes through the rotary shaft and supplies paint or a solvent to the rotary atomizing head. In
The front end portion of the paint supply pipe is formed in a trumpet shape, and a paint reservoir portion recessed backward is formed on the inner wall surface of the rotary atomizing head on the periphery of the front end portion of the paint supply pipe. A rotary atomizing coating apparatus characterized in that, in the axial direction of the shaft, the front end portion of the paint supply pipe and the front end portion of the paint reservoir portion are substantially matched . On the inner wall surface of the rotary atomizing head, a paint reservoir that is recessed backward is formed at the periphery of the front end of the paint supply pipe, and is placed in the middle of the inner wall surface of the rotary atomizing head and centrifuged into the paint. The rotary atomizing coating apparatus according to claim 1, wherein a concave portion recessed forward is formed in a portion facing the paint reservoir portion in the closing member for applying force.

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