JP2015029961A - Electrostatic coating device for conductive material dispersion coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic coating device for conductive material dispersion coating which effectively reduces a device cost and an operation cost by preventing bridging of a conductive material in the coating with a rational agitation form and also effectively materializes energy saving.SOLUTION: An electrostatic coating device for conductive material dispersion coating is provided with agitation means which prevents the bridging of a conductive material in the coating from being formed in the coating T on a supply path 8 by an electric field formed between an earth part E for electrically grounding the coating T in the supply path 8 and a voltage applying part 5d located on the further downstream side than the earth part E. Therein, the agitation means is configured such that a partial portion in a coating flow direction of the supply path 8 between the voltage application part 5d and the earth part E is set as an agitation part C, and driving agitation means D, which blocks the formation of the bridging on the agitation part C by agitating the coating T with a generation driving force on the agitation part C irrespective of the presence or absence of coating feed to the side of the voltage application part 5d through the supply path 8, is provided.

Description

  The present invention relates to an electrostatic coating apparatus for conductive material-dispersed paint that performs electrostatic coating using a paint in which a conductive material is dispersed in a non-conductive solvent, and more specifically, the conductive material is dispersed in a non-conductive solvent. A paint tank for storing paint is provided, and a spray part for spraying the paint fed from the paint tank through a supply path by a supply pump, and the paint sprayed from the spray part are charged by applying a high voltage at the stage before spraying. And a voltage applicator to be provided, and the supply path by an electric field formed between an earth part for electrically grounding the paint in the supply path and the voltage application part located downstream of the ground part The present invention relates to an electrostatic coating apparatus for a conductive material-dispersed paint provided with a stirring means for preventing the formation of a bridge of a conductive material in the paint by stirring the paint.

When electrostatic coating is performed using paint in which a conductive material is dispersed in a non-conductive solvent, the voltage application part of the coating machine that is in a state of applying a high voltage to the paint and the supply path upstream from it An electric field is formed between the ground part and the electric field, and the electric field causes a bridging phenomenon in which the conductive materials in the paint are coupled to each other between the voltage application part and the ground part in the supply path and are connected in the longitudinal direction of the supply path ( A so-called bridge) occurs.
In addition, this bridging is more likely to occur at the time of spraying stop when the feeding of the paint is stopped and the stirring of the conductive material in the paint due to the flow of the paint is stopped than when the paint is sprayed with a paint flow.

  However, when a bridging of the conductive material in the paint occurs, an overcurrent flows between the voltage application unit and the grounding unit via the bridged conductive material even though the solvent is non-conductive. For example, a safety device such as an earth leakage breaker is activated, so that the painting operation cannot be performed.

  In order to prevent this bridging, there is a synchronous system in which a high voltage is applied to the paint only when the paint flow is sprayed, and the high voltage application is stopped when the spray is stopped when the paint feed is stopped. Although it can be considered, even with this synchronous method, when high voltage application is started with the start of paint spraying, the charging of the paint becomes insufficient due to the delay of the rise of the voltage, and furthermore, the high voltage with the stop of paint spraying There is a problem that, when the application is stopped, the conductive material in the paint is bridged by the residual high voltage.

  In contrast, conventionally, a return path is provided for returning the paint fed from the paint tank to the three-way valve in the vicinity of the coating machine through the supply path by the supply pump and returning the paint to the three-way valve when spraying the paint. In parallel with sending a part to the spraying part of the sprayer, the remaining part of the paint fed to the three-way valve was returned to the paint tank through the return path, and when the spraying was stopped, it was fed to the three-way valve. An electrostatic coating apparatus has been proposed in which the entire amount of paint is returned to the paint tank through a return path, thereby preventing bridging of the conductive material in the paint (see Patent Document 1).

  That is, in this electrostatic coating apparatus, the supply path and the return path between the three-way valve and the paint tank are constantly circulated through the return path by the supply pump between the three-way valve and the paint tank in the vicinity of the coating machine. The paint is constantly stirred, and this continuous stirring prevents bridging of the conductive material in the paint in the supply path between the voltage application section of the coating machine and the supply pump as the ground section.

  In addition to the continuous circulation of the paint between the three-way valve and the paint tank through this return path, an agitating guide device is provided in the supply path and the return path to bring the fluid paint into a stirring state by guiding the fluid paint as the paint flows. And the electrostatic coating apparatus which improved the bridging prevention function by this is also proposed (refer patent document 2).

Japanese Patent Publication No.51-28302 Japanese Patent Publication No.61-40471

  However, in the electrostatic coating apparatuses of Patent Document 1 and Patent Document 2, the paint is constantly circulated through a long circulation path from the three-way valve in the vicinity of the coating machine to the paint tank (in other words, the circulation path over the entire apparatus). In addition, a large pump with a high head is required for the supply pump for feeding paint, which also serves as a pump for continuous circulation, and this also increases the power consumption of the pump, increasing the equipment cost and operation cost, and saving energy. There was a problem going backwards.

  Moreover, in the electrostatic coating apparatus of the said patent document 1 and the patent document 2, the bridge prevention by a paint circulation does not reach between the three-way valve which is a branch point of the return path in a supply path, and the voltage application part in a coating machine. When the three-way valve is electrically grounded, a bridging of the conductive material in the paint occurs between the voltage application unit and the three-way valve, and overcurrent flows. Therefore, the three-way valve and the open / close valve arranged downstream of it Etc. have to be electrically insulated, which has also contributed to an increase in apparatus cost.

  In view of this situation, the main object of the present invention is to effectively solve the above-described problems by preventing bridging of the conductive material in the paint with a rational stirring mode.

A first characteristic configuration of the present invention relates to an electrostatic coating apparatus for a conductive material-dispersed paint,
A paint tank is provided to store paint in which conductive material is dispersed in a non-conductive solvent.
A coating machine comprising: a spraying section for spraying paint fed from a paint pump through a supply path by a supply pump; and a voltage applying section for charging paint sprayed from the spraying section by applying a high voltage in a stage before spraying Provided,
A bridge of the conductive material in the paint is formed in the paint in the supply path by an electric field formed between the ground part for electrically grounding the paint in the supply path and the voltage application part located downstream thereof. An electrostatic coating apparatus for a conductive material-dispersed paint provided with stirring means for preventing the paint from being stirred,
To constitute the stirring means, a part in the paint flow direction of the supply path between the voltage application part and the ground part is used as a stirring part to the side of the voltage application part through the supply path. Regardless of whether or not the paint is fed, there is provided a drive agitation means for preventing the formation of the bridge in the agitation part by agitating the paint in the agitation part with the generated driving force.

  That is, in this configuration, a part of the supply path between the voltage application unit and the ground unit in the paint flow direction is a stirring unit, and the paint in the stirring unit is stirred by the generated driving force of the drive stirring unit. The coupling | bonding by the electric field of the electrically conductive material in a coating material in the stirring part is blocked | prevented.

  Therefore, by always operating this drive agitating means, the voltage application unit and the ground are connected regardless of whether or not the paint is supplied to the side of the voltage application unit through the supply path (that is, whether or not paint is sprayed from the spray unit). Bridging of the conductive material in the paint between the voltage application part and the ground part due to the electric field formed between the parts can be reliably prevented in the stirring part.

  And according to this structure, since it only stirs a paint in the one part (stirring part) in the paint flow direction of a supply path, it is a coating machine compared with the electrostatic coating apparatus of patent document 1 and patent document 2 mentioned above. It eliminates the need for a long circulation path from the nearby three-way valve to the paint tank (i.e., a circulation path that spans the entire coating device), so that the supply pump also feeds the paint to the coating machine. It is possible to use only a small pump with a low head, and the driving force required for the separately provided drive agitation means is small, and the drive agitation means itself is also small, which effectively reduces the equipment cost and operation cost. Energy saving can be effectively promoted.

  Furthermore, according to this configuration, the stirring portion for stirring the paint by the drive stirring means can be disposed at an arbitrary position in the supply path between the voltage application portion and the ground portion, and thus the ground portion can also be the voltage application portion. It is possible to dispose it closer to the downstream side, thereby increasing the area in the device that is located upstream from the grounding portion and does not require electrical insulation. Costs can be reduced more effectively.

The second feature configuration of the present invention specifies an embodiment suitable for the implementation of the first feature configuration.
To constitute the drive stirring means, a part of the paint in the supply path is extracted from the branch portion by a circulation pump, and the extracted paint is returned to the supply path at a junction upstream of the branch portion. A circulation path is provided in the supply path between the voltage application unit and the ground unit,
Regardless of whether or not paint is supplied to the side of the voltage application unit through the supply path, the branch part in the supply path and the branching section in the supply path as the stirring unit The present invention lies in a configuration in which the paint between the merging portion is stirred by the paint circulation through the local circulation path by the circulation pump.

  That is, in this configuration, as agitation of the paint at a part of the supply path in the paint flow direction (the agitation part), the branch part and the junction part in the supply path are caused by paint circulation through the local circulation path by a circulation pump In this stirring, the turbulence of the paint accompanying the paint merging at the junction and the turbulence of the paint accompanying the paint extraction at the branch are combined. Can be effectively stirred, and the coupling of the conductive material in the paint due to the electric field between the joining portion and the branching portion can be effectively prevented.

  Therefore, according to this configuration, by always operating the circulation pump, the voltage is supplied regardless of whether or not paint is supplied to the side of the voltage application unit through the supply path (that is, whether or not paint is sprayed from the spray unit). Bridging of the conductive material in the paint between the application part and the ground part can be prevented more reliably and effectively between the branch part and the junction part.

  Further, in this configuration, the local circulation path may be a short-circuit circulation path with respect to a part of the supply path in the paint flow direction, so that the circulation pump may be very small.

The third feature configuration of the present invention specifies an embodiment suitable for the implementation of the first feature configuration.
To constitute the drive stirring means, a part of the paint in the supply path is extracted from the branch portion by a circulation pump, and the extracted paint is returned to the supply path at a junction upstream of the branch portion. A circulation path is provided in the supply path in a state where the branch part is arranged between the voltage application part and the earth part and the junction part is arranged upstream of the earth part,
Regardless of whether or not paint is supplied to the side of the voltage application unit through the supply path with the branch unit as the stirring unit, the paint in the branch unit is circulated by the paint circulation through the local circuit by the circulation pump. It is in the point which is set as the structure which stirs.

  That is, in this configuration, as in the second feature configuration, the paint between the branching portion and the joining portion in the supply path is always stirred by the paint circulation in the local circulation path by the continuous operation of the circulation pump, so that the conductive material in the paint In particular, in this configuration, the downstream branching portion is disposed between the voltage application unit and the grounding portion, whereas the upstream junction portion is disposed upstream of the grounding portion. This ensures the bridging of the conductive material in the paint between the voltage application part and the ground part between the branch part and the ground part (especially in the vicinity of the branch part where the stirring effect due to turbulence of the paint is large). To prevent.

  And according to this structure, since only a branch part is arrange | positioned between a voltage application part and a ground part among a branch part and a confluence | merging part, the separation dimension of the voltage application part and ground part in a coating machine is made small. The grounding portion can be disposed at a location closer to the downstream side closer to the voltage applying portion, which can further increase the area in the device where no electrical insulation is required, thereby reducing the device cost. Can be further reduced.

The fourth feature configuration of the present invention specifies an embodiment suitable for the implementation of the first feature configuration.
A vibration device for agitating the paint in the agitation unit by generated vibration regardless of the presence or absence of the paint supply to the side of the voltage application unit through the supply path is configured in the supply path. It exists in the point provided in the said stirring part.

  That is, in this configuration, by arranging the vibration device arrangement portion arranged in a part of the supply flow direction in the supply path as the agitating portion, the paint in the vibration device arrangement portion is agitated by the generated vibration of the vibration device, The coupling | bonding by the electric field of the electrically conductive material in a coating material in a vibration apparatus arrangement | positioning part is blocked | prevented.

  Therefore, according to this configuration, by always operating the vibration device, the paint can be applied regardless of whether or not the paint is supplied to the voltage application unit side through the supply path (that is, whether or not the paint is sprayed from the spray unit). The bridging of the middle conductive material can be reliably prevented at the arrangement portion of the vibration device.

  Further, according to this configuration, the generated driving force of the vibration device is small, and even the formation of the local circulation path as in the second and third characteristic configurations can be made unnecessary, thereby further reducing the cost of the device. Can be reduced.

The fifth characteristic configuration of the present invention specifies an embodiment suitable for any one of the first, second, and fourth characteristic configurations, and the characteristic is
An opening / closing valve for opening and closing the supply path is interposed in the supply path as the ground portion.

  In other words, the open / close valve that opens and closes the supply path is disposed as downstream as possible in the supply path for the purpose of reducing the amount of waste paint when changing the color of the paint and reducing the necessary cleaning range in the supply path. As described above, the opening / closing valve is used for the ground portion as described above, so that the electrical insulation of the opening / closing valve becomes unnecessary and the electrical insulation becomes unnecessary. The area in the apparatus can be further increased, and thereby the apparatus cost can be further reduced.

The sixth feature configuration of the present invention specifies an embodiment suitable for the implementation of any of the first to fourth feature configurations.
The rear end portion of the coating machine is the ground portion.

  In other words, according to this configuration, it is possible to eliminate the need for electrical insulation for all the in-apparatus regions located upstream of the rear end of the coating machine, thereby further effectively reducing the equipment cost. can do.

Schematic configuration diagram of the electrostatic coating apparatus of the first embodiment Longitudinal sectional view of the coating machine of the electrostatic coating apparatus of the first embodiment Circuit diagram of electrostatic coating apparatus of first embodiment Circuit diagram of electrostatic coating apparatus of second embodiment Circuit diagram of electrostatic coating apparatus of third embodiment

[First Embodiment]
FIG. 1 shows an example of a conductive material-dispersed paint in which a conductive material is dispersed in a non-conductive solvent, with respect to a resin coating 3 (in this example, a car bumper) in which a conductive primer T is transported by a transport device 2. 1 shows an electrostatic coating apparatus 1 for electrostatic coating. The electrostatic coating apparatus 1 includes a coating robot 4 having a movable arm 4a, and a rotary atomizing electrostatic coating machine 5 is provided at the tip of the movable arm 4a. Is equipped.

  In this example, the conductive primer T is a primer in which powder carbon as a conductive material is dispersed in thinner as a nonconductive solvent, and the coating target surface 3a of the resin article 3 by electrostatic coating of the conductive primer T. A conductive primer layer is formed on the surface to enable the formation of an electric field between the electrostatic coating machine for overcoating and the resin-coated object 3, so that the coating target surface 3 a of the resin-coated object 3 (specifically In particular, the top coat can be applied by normal electrostatic painting using a water-based paint or the like on the surface of the conductive primer layer.

  Further, in electrostatic coating of the conductive primer T itself, an appropriate temporary conductive treatment such as attaching a conductive material (not shown) to the back surface 3b of the resin coated object 3 is performed, so that the resin coated object is obtained. 3 and the coating machine 5 can be formed, whereby the conductive primer T is electrostatically coated on the coating target surface 3a of the resin article 3 to be coated.

  6 is a paint tank for storing the conductive primer T, 7 is a supply pump for feeding the conductive primer T in the paint tank 6 to the coating machine 5 through the supply path 8, and the supply path 8 is routed through the movable arm 4a of the coating robot 4. And it is passed to the painting machine 5.

  An open / close valve 9 opens and closes the supply path 8, and the supply of the conductive primer T to the coating machine 5 is interrupted by opening / closing the supply path 8 by the open / close valve 9.

  As shown in FIG. 2, at the tip of the coating machine 5, the conductive primer T fed through the supply passage 8 is sprayed onto the resin article 3 as a spraying portion from the tip of the supply passage 8 to the inner surface of the cup. A bell cup 5a is provided that sprays the conductive primer T discharged to the center part in an atomization form in which the conductive primer T is subdivided and scattered from the outer periphery of the cup by centrifugal force due to high-speed rotation of the cup.

  In addition, a turbine 5b that rotates the bell cup 5a at a high speed and a high voltage generator 5c that generates a high voltage (negative high voltage in this example) are provided inside the coating machine 5, and the high voltage generator 5c is provided. Is applied to a part of the supply path 8 and applied to the bell cup 5a via the turbine 5b, so that a part of the supply path 8 and the part of the bell cup 5a from the turbine 5b are electrically conductive primer T. As a voltage application unit 5d, the high voltage generated by the high voltage generator 5c is applied to the conductive primer T fed to the coating machine 5 from the passage process inside the coating machine to the spraying process in the bell cup 5a. The conductive primer T sprayed from the cup 5a is charged.

  That is, by spraying the charged conductive primer T from the bell cup 5a, the charged spray conductive primer T is subjected to appropriate temporary conductive treatment, and the resin coated article 3 is subjected to a high voltage application state. It is made to fly by the electric force by the electric field formed between 5a and apply | coated to the coating target surface 3a of the resin to-be-coated object 3, and, thereby, the above-mentioned conductive primer layer is applied to the to-be-coated surface 3a of the resin to-be-coated object 3 Form.

  In addition to the opening / closing valve 9, a trigger valve 5e for opening / closing the supply path 8 is provided inside the coating machine 5, and when the resin article 3 is absent, the supply path 8 is closed by the opening / closing valve 9 so that the bell cup 5a. When the feeding of the conductive primer T to the resin is stopped and the coating robot 4 is applied to the resin workpiece 3, the bell cup 5a is opened and closed by opening and closing the trigger valve 5e linked to the coating operation of the coating robot 4. The spraying of the conductive primer T from is interrupted.

  The opening / closing valve 9 for opening and closing the supply path 8 is mounted on the movable arm 4a of the painting robot 4 together with the painting machine 5 so as to be arranged as close as possible to the painting machine 5, so that the opening / closing valve 9 is mounted on the painting robot 4. The amount of the conductive primer T that needs to be discarded when the bell cup 5a is washed in the coating machine 5 as compared with the upstream side of the supply path 8 (that is, the downstream side of the opening / closing valve 9 in the supply path 8). The amount of the conductive primer T remaining in the portion is reduced as much as possible.

  In an electrostatic coating apparatus that directly applies a high voltage to the paint before spraying, a grounding unit E for electrically grounding the paint in the supply path 8 is applied to the coating machine in order to reliably avoid a leakage accident to an unexpected location. 5 is provided on the supply path 8 upstream of the voltage application unit 5d in the direction of paint flow, but a static material using a conductive material-dispersed paint (hereinafter simply referred to as paint T) may be used, including the conductive primer. In the electropainting, the conductive material in the paint is connected to the paint T in the supply path 8 by the electric field formed between the ground part E and the voltage application part 5 d in the coating machine 5, and continues in the longitudinal direction of the supply path 8. A bridge is formed.

  Then, due to the occurrence of this bridging, an overcurrent occurs between the voltage application part 5d and the ground part E, which causes a problem that the electrostatic coating operation becomes impossible. In the electrostatic coating apparatus 1 of this example, as the stirring means for preventing the formation of the bridge by stirring the paint T, the ground portion E arranged on the most downstream side in the paint flow direction and positioned further downstream than that. A part of the supply path 8 in the direction of paint flow with the voltage application unit 5d is a stirring unit C, regardless of whether paint is supplied to the voltage application unit 5d (ie, whether paint is sprayed). Drive agitating means D for preventing the formation of the bridge in the agitator C by agitating the paint T in the agitator C with the generated driving force is provided.

  Further, the opening / closing valve 9 is electrically grounded as the earth portion E for electrically grounding the paint in the supply path 8, and is thereby positioned upstream of the opening / closing valve 9 in the paint flow direction. For most of the supply path 8 around, electrical insulation treatment for preventing leakage is unnecessary.

  As for the specific configuration of the drive stirring means D, as shown in FIG. 3, between the opening / closing valve 9 also serving as the ground portion E and the voltage applying portion 5d of the coating machine 5, and upstream of the trigger valve 5e. A local circulation path 10 having a short path length connected to the supply path 8 at two locations of a downstream branching portion 8a and an upstream junction portion 8b is provided at a part of the supply path 8, and a local portion of the short path length is provided. A small circulation pump 11 having a low head sufficient to allow the paint to pass through the circulation path 10 is interposed in the local circulation path 10, and the circulation pump 11 is always operated so that the voltage by the supply pump 7 through the supply path 8 is maintained. Regardless of whether or not paint is supplied to the application unit 5d side (in other words, whether or not paint is sprayed), the portion of the supply path 8 between the branching portion 8a and the merging portion 8b is referred to as the stirring portion C. Local circulation of paint T in stirring section C It is so as to circulate constantly through 10.

  In other words, the continuous circulation of the paint T through the local circulation path 10 cooperates with the turbulent flow by the paint extraction at the branching portion 8a and the turbulent flow by the paint merging at the merging portion 8b. The formation of a bridging of the conductive material in the paint by bonding of the conductive materials in the paint in an electric field is performed at the above-described stirring portion C (branch) that is a part of the supply path 8 during the spraying of the paint and when the spraying of the paint is stopped. This is reliably prevented at the portion between the portion 8a and the merging portion 8b.

[Second Embodiment]
FIG. 4 shows a circuit diagram of an electrostatic coating apparatus 1 that performs electrostatic coating using a conductive material-dispersed paint such as a conductive primer in which a conductive material is dispersed in a non-conductive solvent, as in the first embodiment. In the electrostatic coating apparatus 1, drive generating means for preventing the formation of a bridge of the conductive material in the paint in the stirring portion C by stirring the paint T of the stirring portion C, which is a part of the supply path 8, with the generated driving force. In the same way as in the first embodiment, a short path length connected to the supply path 8 at two locations of the downstream branching portion 8a and the upstream merging portion 8b is configured to form D. A local circulation path 10 is provided, and a small circulation pump 11 is interposed in the local circulation path 10.

On the other hand, an earthing portion E (grounding portion arranged on the most downstream side in the paint flow direction) for electrically grounding the paint in the supply path 8 is the rear end of the coating machine 5 located further downstream than the opening / closing valve 9. Specifically, an earth plate 5f is provided at the rear end of the coating machine 5, and the earth plate 5f is electrically grounded.
On the other hand, the local circulation path 10 has a downstream branching portion 8a between the ground plate 5f serving as the grounding portion E inside the coating machine 5 and the voltage applying portion 5d downstream of the grounding plate E. Further, it is arranged upstream of the trigger valve 5e, and is connected to the supply path 8 in a state where the upstream junction 8b is arranged between the earth plate 5f as the earth part E and the open / close valve 9. .

  That is, in this electrostatic coating apparatus 1, the portion between the branch portion 8 a of the local circulation path 10 in the supply path 8 and the earth plate 5 f as the earthing section E (particularly, the turbulence associated with the paint extraction to the local circulation path 10. The vicinity of the branching portion 8a having a high paint stirring effect due to fluidization is provided as the stirring portion C disposed between the ground portion E and the voltage application portion 5d downstream of the grounding portion E, whereby the circulation pump 11 Regardless of whether or not paint is supplied to the side of the voltage application unit 5d by the supply pump 7 through the supply path 8 by the constant circulation of the paint T through the local circulation path 10 in the normal operation (that is, whether or not the paint is sprayed). The formation of a bridge between the conductive materials in the paint due to the bonding between the conductive materials in the paint in an electric field is reliably prevented at the stirring portion C (a portion near the branching portion 8a).

[Third Embodiment]
FIG. 5 also shows a circuit diagram of the electrostatic coating apparatus 1 for conductive material-dispersed paint. In this electrostatic coating apparatus 1, the paint in the supply path 8 is electrically grounded by the open / close valve 9 as in the first embodiment. The ground portion E (the ground portion disposed on the most downstream side in the paint flow direction) is used.

  On the other hand, the drive stirring means D is configured to block the formation of the bridging of the conductive material in the paint in the stirring portion C by stirring the paint T of the stirring portion C which is a part of the supply path 8 by the generated driving force. For this purpose, a vibration device 12 is provided at a part of the supply path 8 in the paint flow direction between the opening / closing valve 9 also serving as the ground portion E and the voltage application portion 5d of the coating machine 5. The coating material T in the supply path 8 at the arrangement location is stirred by the vibration force generated by the vibration device 12.

  That is, in this electrostatic coating apparatus 1, the stirring section C is disposed as the stirring section C in which the location of the vibration device 12 in the supply path 8 is disposed between the ground section E and the voltage application section 5 d on the downstream side. The paint T in C is agitated by the vibration force generated by the vibration device 12, and thus the paint is applied to the voltage application unit 5 d side by the supply pump 7 through the supply path 8 by always operating the vibration device. Regardless of the presence or absence of feeding (that is, the presence or absence of paint spraying), the stirrer C (placement position of the vibration device 12) forms the bridge of the conductive material in the paint by the coupling of the conductive materials in the paint in the electric field. Surely stop.

[Another embodiment]
Next, another embodiment will be listed.

  A part of the supply path 8 in the paint flow direction between the ground part E (the ground part arranged on the most downstream side in the paint flow direction) and the voltage application part 5d located further downstream than the ground part E is stirred. As C, regardless of whether or not paint is supplied to the voltage application unit 5d through the supply path 8, the paint T in the stirring unit C is stirred by the generated driving force to form a bridge of the conductive material in the paint. The driving agitating means D for blocking in the agitating portion C includes a local circulation path 10 in which both the branching portion 8a and the merging portion 8b as shown in the first embodiment are disposed between the ground portion E and the voltage applying portion 5d. In addition, a local circuit 10 including the circulation pump 11 provided therein or a branching portion 8a as shown in the second embodiment is disposed between the grounding portion E and the voltage application portion 5d, and the circulation of the local circulation path 10 is provided. There are pumps 11 Is not limited to the vibration device 12 disposed between the ground portion E and the voltage application portion 5d shown in the third embodiment, and may be any device that stirs the paint T of the stirring portion C by generated power. Any stirring system may be used.

  In the first and third embodiments, the opening / closing valve 9 that opens and closes the supply path 8 is the ground portion E, and in the second embodiment, the ground portion E is the ground plate 5f provided at the rear end of the coating machine 5. The ground portion E (the ground portion on the most downstream side) for electrically grounding the paint T in the supply path 8 is not limited to this, and is disposed at any location in the supply path 8 as long as it is upstream of the voltage application section 5d. May be.

  For example, when the driving agitating means D is constituted by the local circulation path 10 in which both the branching section 8a and the merging section 8b are arranged between the ground section E and the voltage application section 5d and the circulation pump 11 interposed therebetween, the vibration In the case where the drive stirring means D is constituted by the apparatus 12, the grounding part E is replaced with the grounding part E such as the grounding plate 5f provided at the rear end of the coating machine 5 instead of the opening / closing valve 9 as the grounding part E. May be provided in the supply path 8 at a place other than the opening / closing valve 9.

  Further, in the case where the driving agitating means D is constituted by the local circulation path 10 in which only the branching section 8a is arranged between the ground section E and the voltage application section 5d and the circulation pump 11 interposed therein, the branch of the local circulation path 10 is formed. In a form in which the portion between the portion 8a and the junction portion 8b is not an intervening place of the opening / closing valve 9, the ground portion E is supplied between the opening / closing valve 9 and the rear end of the coating machine or upstream of the opening / closing valve 9. Eight may be equipped.

  The coating machine 5 is not limited to the rotary atomization type electrostatic coating machine using the bell cup 5a as a spraying section, but if the type of electrostatic coating machine applies a voltage to the coating T in the stage before spraying, the coating machine T Any type of electrostatic coating machine may be used, such as a type of electrostatic coating machine that sprays from a spray section with compressed air.

  Further, the high voltage generator 5c for supplying the generated high voltage to the voltage application unit 5d of the coating machine 5 is not limited to being installed in the coating machine 5 together with the voltage application unit 5d, but is disposed outside the coating machine 5. There may be.

  In the first to third embodiments, an example in which the opening / closing valve 9 that opens and closes the supply path 8 is provided in the supply path 8, but instead, a paint that selectively switches the supply paint T to the coating machine 5. An opening / closing valve having a function of a switching valve may be interposed in the supply path 8, or a paint switching valve and an opening / closing valve may be arranged in that order from the upstream side and interposed in the supply path 8.

  The conductive material-dispersed paint T sprayed from the coating machine 5 is not limited to a conductive primer in which a conductive material such as powder carbon is dispersed in a non-conductive solvent such as thinner, and a paint that may cause a bridging of the conductive material in the paint. As long as it is, any paint such as a paint in which a conductive pigment or a glittering material is dispersed in a non-conductive solvent may be used.

  The electrostatic coating apparatus for conductive material-dispersed paint according to the present invention can be used for various types of electrostatic coating in various fields.

T paint 6 paint tank 7 supply pump 8 supply path 5a spraying part 5d voltage application part 5 coating machine E grounding part 1 electrostatic coating apparatus C stirring part D drive stirring means 11 circulating pump 8a branching part 8b merging part 10 local circulation path 12 Vibration device 9 Open / close valve 5f Rear end of paint machine (ground plate)

Claims (6)

A paint tank for storing paint in which conductive material is dispersed in a non-conductive solvent is provided.
A coating machine comprising: a spraying section for spraying paint fed from a paint pump through a supply path by a supply pump; and a voltage applying section for charging paint sprayed from the spraying section by applying a high voltage in a stage before spraying Provided,
A bridge of the conductive material in the paint is formed in the paint in the supply path by an electric field formed between the ground part for electrically grounding the paint in the supply path and the voltage application part located downstream thereof. An electrostatic coating apparatus for a conductive material-dispersed paint provided with stirring means for preventing the paint from being stirred,
To constitute the stirring means, a part in the paint flow direction of the supply path between the voltage application part and the ground part is used as a stirring part to the side of the voltage application part through the supply path. Regardless of whether or not the paint is fed, electrostatic charge for a conductive material-dispersed paint provided with a drive stirring means for preventing the formation of the bridge in the stirring section by stirring the paint in the stirring section with the generated driving force. Painting equipment. To constitute the drive stirring means, a part of the paint in the supply path is extracted from the branch portion by a circulation pump, and the extracted paint is returned to the supply path at a junction upstream of the branch portion. A circulation path is provided in the supply path between the voltage application unit and the ground unit,
Regardless of whether or not paint is supplied to the side of the voltage application unit through the supply path, the branch part in the supply path and the branching section in the supply path as the stirring unit 2. The electrostatic coating apparatus for conductive material-dispersed coating material according to claim 1, wherein the coating material is mixed with the joining portion by stirring the coating material through the local circulation path by the circulation pump. To constitute the drive stirring means, a part of the paint in the supply path is extracted from the branch portion by a circulation pump, and the extracted paint is returned to the supply path at a junction upstream of the branch portion. A circulation path is provided in the supply path in a state where the branch part is arranged between the voltage application part and the earth part and the junction part is arranged upstream of the earth part,
Regardless of whether or not paint is supplied to the side of the voltage application unit through the supply path with the branch unit as the stirring unit, the paint in the branch unit is circulated by the paint circulation through the local circuit by the circulation pump. 2. The electrostatic coating apparatus for conductive material-dispersed paint according to claim 1, wherein the apparatus is agitated.   A vibration device for agitating the paint in the agitation unit by generated vibration regardless of the presence or absence of the paint supply to the side of the voltage application unit through the supply path is configured in the supply path. The electrostatic coating apparatus for conductive material-dispersed paint according to claim 1, which is provided in the stirring unit.   The electrostatic coating device for conductive material-dispersed paint according to claim 1, wherein an opening / closing valve for opening and closing the supply path is interposed in the supply path as the ground portion.   The electrostatic coating apparatus for conductive material-dispersed paint according to claim 1, wherein a rear end portion of the coating machine is used as the ground portion.

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