JP2011067711A - Electrostatic coating machine provided with detachable paint cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clean a paint flow path of a coating machine body, including a connected part of the coating machine body to a paint cartridge, that is, a paint outlet of the paint cartridge. <P>SOLUTION: The paint cartridge 10 has a stepped sleeve 300 positioned to be projected downward from the lower end surface and capable of displacing up and down. A valve seat 302 of a first check valve 30 is formed at the lower end of the stepped sleeve 300. A movable valve element 304 seated on the valve seat 302 is energized by an inner peripheral spring 306 in a direction of being seated on the valve sheet 302. On the other hand, the stepped sleeve 300 is energized downward by an outer peripheral spring 308. A second recessed part 402 for receiving a small diameter part 300a of the stepped sleeve 300 is formed in a recessed part 40 of the coating machine body 6. A paint feeding channel 44 is opened in the center of the bottom surface of the second recessed part 402. A seal ring 404 is arranged on the outer periphery of the opening of the paint feeding channel 44. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates generally to an electrostatic coating machine, and more particularly to an electrostatic coating machine including a removable paint cartridge.

  2. Description of the Related Art A paint cartridge type electrostatic coating machine is known as an electrostatic coating machine suitable for conductive paints such as water-based paints and metallic paints. The paint cartridge type electrostatic coating machine has a paint cartridge that is detachably attached to the main body of the paint machine, and an automobile body or the like is painted using a conductive paint contained in the paint cartridge. The paint cartridge type electrostatic coating machine has an advantage that high voltage can be blocked from leaking outside through the conductive paint.

  Traditional electrostatic coating machines that receive paint from an external paint source are broadly divided into rotary atomizers with rotary atomizing heads (so-called “bell cups”) and spray type painters. Of course, the paint cartridge is applied to both types of coating machines.

  The paint cartridge is also called a paint cassette or a paint tank unit, and can be broadly divided into a piston type (Patent Documents 1 to 3) for extruding paint with a piston, and second, a pressure applied to the paint bag. In addition, it can classify | categorize into the paint bag type (patent documents 4-7) which extrudes a paint from a paint bag by crushing a paint bag.

  Specifically, the piston type paint cartridges of Patent Documents 1 to 3 have a paint storage chamber defined by a piston, and a hydraulic fluid chamber on the opposite side of the paint storage chamber across the piston. A working fluid (typically a non-conductive liquid such as thinner) is supplied to the liquid chamber, and the piston is pushed down to push the paint in the paint chamber from the paint cartridge, and this paint is supplied to the bell cup through the feed tube. In addition, since the coating material cartridge of patent documents 1-3 is equipped with the feed tube which can be inserted in a coating machine main body, it can also be called a coating material cartridge with a feed tube.

  As described above, Patent Document 4 discloses a paint cartridge including a paint bag that forms a paint storage chamber. However, the paint cartridge of Patent Document 4 includes a feed tube that can be inserted into a main body of a coating machine. I have. Therefore, the paint cartridge disclosed in Patent Document 4 can also be called a paint cartridge with a feed tube. Patent document 4 is disclosing two methods as a method of crushing a paint bag. One of them is a method in which a working fluid is supplied around the paint bag, and the paint bag is crushed by applying pressure directly to the paint bag with the working fluid. The other one is a working fluid bag that is adjacent to the paint bag and forms a working fluid chamber, supplies the working fluid to the working fluid bag to expand the working fluid bag, and expands the working fluid bag. In this method, pressure is applied to the paint bag to crush the paint bag.

  Patent Document 5 discloses a paint cartridge including a paint bag and a hydraulic fluid bag, in which contact surfaces of the paint bag and the hydraulic fluid bag are connected to each other to prevent relative displacement between the paint bag and the hydraulic fluid bag. Has proposed. Moreover, this patent document 5 has proposed filling the clearance gap between a coating material bag and a hydraulic fluid bag with a liquid.

  Patent Document 6 proposes a paint cartridge in which an outer case of a paint cartridge provided with a paint bag is made of nylon resin, which is a transparent hard plastic, so that the inside can be observed. Patent Document 6 discloses that the paint bag is also made of a transparent resin.

  Patent Document 7 discloses a bag-type paint cartridge without a feed tube. This bag type paint cartridge has a sleeve that constitutes a paint outlet port of the paint cartridge, and a one-way valve constituted by a ball valve (movable valve) is attached to the sleeve. The coating machine main body on which the paint cartridge is mounted has a shutter that opens and closes the upstream end of the paint passage in the coating machine main body. The coating machine body also has a cleaning liquid supply passage that receives a supply of cleaning liquid from the outside. When the shutter is in a closed state, the cleaning liquid passes through a connecting passage formed by the shutter (referred to as a “shutter passage”). A supply passage communicates with the paint passage.

  An opening / closing valve is interposed in the middle of the cleaning liquid supply passage. This on-off valve is mechanically linked to the shutter. The open / close valve is closed when the shutter is opened, and the open / close valve is opened when the shutter is closed. When the bag-type paint cartridge is mounted on the main body of the paint machine, the shutter is opened, and the paint outlet port of the cartridge communicates with the paint passage in the main body of the paint machine. Thereby, a coating material can be supplied to a coating machine main body from a cartridge (painting bag). When the paint cartridge becomes empty and the paint cartridge is removed from the main body of the coating machine, the shutter is closed, and the cleaning liquid on-off valve is opened in conjunction with the closing operation of the shutter. As described above, the shutter passage is formed by the closed shutter, and the cleaning liquid supply passage and the paint passage are communicated with each other through the shutter passage. When the cleaning liquid is supplied from the outside to the coating machine main body (cleaning liquid supply passage) with the paint cartridge removed, the coating liquid passage in the coating machine main body can be cleaned by this cleaning liquid.

  Note that a membrane pump described in Patent Document 8 is known as a method of extruding a paint using a working fluid. The membrane pump of Patent Document 8 is not related to a paint cartridge. However, the case of the membrane pump has a paint port opened at one end surface thereof and a hydraulic fluid port opened at the other end surface, and the inside of the case is divided into a paint storage chamber and a hydraulic fluid chamber by a stretchable membrane. It is partitioned. By supplying the hydraulic fluid to the hydraulic fluid chamber through the hydraulic fluid port, the coating material filled in the coating material storage chamber flows out through the coating material port, and the discharged coating material is supplied to the electrostatic coating machine. Therefore, the principle of the membrane pump of Patent Document 8 is applicable to a paint cartridge.

  The amount of paint that can be accommodated in the paint cartridge that can be attached to and detached from the coating machine body is finite. For this reason, for example, when the painting of one automobile body is completed, the paint cartridge is replaced for painting the next automobile body.

  Patent Document 9 discloses a technical disclosure relating to the replacement of a paint cartridge of a painting robot equipped with an electrostatic coating machine. Specifically, when painting of one automobile body is completed, the used paint cartridge is removed from the paint machine body at the paint cartridge exchange station, and then a new paint cartridge is mounted on the paint machine body. That is, the paint cartridge is replaced. While the painting robot is painting the car body, the paint cartridge replacement station is used to fill the used paint cartridge with paint, and the paint cartridge filled with paint is used for reuse. Stocked.

  With respect to filling the empty paint cartridge with the paint and reusing it, the color change is actually performed in the piston type paint cartridge. In other words, the piston-type paint cartridge is filled with the same color paint, but as described in detail in Patent Documents 1 and 2, the interior of the paint cartridge (the paint storage chamber) is washed to obtain another type. Filling with colored paint is also performed. This is so-called color change. In the disclosure of the paint cartridge in Patent Document 1, the cleaning of the paint cartridge, first, pushes the piston downward to a position before than the deepest portion of the paint chamber, to discharge the paint contained in the paint cartridge. Stopping the piston slightly before it is pushed down to the deepest part without pushing the piston down to the deepest part, even if the piston is pushed down to the deepest part of the paint storage chamber, that is, the bottom wall of the paint storage chamber, This is because the cleaning liquid cannot flow inside the paint chamber. (Paragraph [0153] in the specification of Patent Document 1)

  In this state, that is, in a state where the piston is positioned at a position slightly before the deepest part, the cleaning liquid is supplied to the paint storage chamber through the cleaning liquid supply port opened in the bottom wall of the paint storage chamber. That is, after flowing through the inside of the paint chamber defined by the piston positioned slightly before the deepest part, it is discharged to the outside through the feed tube.

  Patent document 2 points out the problem of the paint cartridge of the said patent document 1 regarding the washing | cleaning of a piston type paint cartridge. As described above, Patent Document 1 proposes that the piston is positioned at a position slightly before the deepest portion, and the inside of the paint chamber defined by the piston is cleaned. As a point, in Patent Document 2, in the method of Patent Document 1, the flow of the cleaning liquid supplied to the paint storage chamber through the cleaning liquid supply port at the bottom of the paint cartridge becomes turbulent, and the interior of the paint storage chamber is evenly distributed. It points out that it cannot be washed. According to Patent Document 2, it is pointed out that it is difficult to wash off the paint entering the gap between the side surface of the piston and the side wall of the paint storage chamber, and it takes time to wash it off. . And in order to solve the problem of patent document 1, patent document 2 has proposed forming the groove | channel extended in the radial direction toward the center part of the said bottom wall in the bottom wall of a coating material storage chamber. .

JP JP 2002-11396 A JP JP 2004-42036 A JP JP 08-229446 A JP JP 2005-87810 A JP JP 2005-296750 A JP JP 2006-347606 A JP JP 2006-334549 A JP Utility Model Publication No. 04-87759 JP JP 2000-317354 A

  Paint cartridge type electrostatic coating machines have been put to practical use for painting automobile bodies. As is well known, a painting robot having an electrostatic coating machine attached to an arm is used for painting an automobile body. When the color of the electrostatic coating machine is changed, the coating machine main body is cleaned as disclosed in Patent Document 7.

  Regarding the color change of the paint cartridge, the piston-type paint cartridge is actually subjected to internal cleaning and filled with another color paint as described above. However, the bag-type paint cartridge is only reused for the same color paint. If the paint in the paint cartridge removed from the main body of the coater is A color paint, Paint is filled into the paint cartridge.

  As described above, the electrostatic coating machine main body is cleaned with the paint cartridge removed from the coating machine main body (Patent Document 7). A problem in cleaning the main body of the coating machine is cleaning of the connecting portion between the main body of the coating machine and the paint cartridge. In Patent Document 7, it is proposed that a shutter is provided at the upper end of the coating machine main body, and an additional cleaning passage is formed at the upper end surface of the coating machine main body, that is, a connecting portion with the paint cartridge by closing the shutter. ing.

  However, the proposal of Patent Document 7 requires a mechanical mechanism that interlocks the shutter with the attachment and detachment of the paint cartridge, and the structure of the main body of the coating machine is complicated, for example, it is necessary to ensure sealing performance around the shutter. . This is a factor that increases the manufacturing cost of the main body of the coating machine.

  An object of the present invention is to provide an electrostatic coating with a paint cartridge that can clean the paint passage of the main body of the coating machine including the connecting portion between the main body of the paint machine and the paint cartridge, that is, the paint outlet of the paint cartridge, while having a simple configuration. Is to provide a machine.

According to the present invention, the above technical problem is
In an electrostatic coating machine that includes a paint cartridge that can be attached to and detached from a coating machine main body, and the coating machine main body receives paint supplied from the paint cartridge and performs coating on a workpiece.
The paint cartridge is
(i) a sleeve constituting the paint outlet of the paint cartridge and displaceable up and down;
(ii) a first spring that biases the sleeve downward;
(iii) a paint opening / closing valve provided on the sleeve and opening / closing an outlet of the paint passage;
The coating machine body is
(i) a recess for receiving the sleeve;
(ii) a paint passage having an opening opened on a bottom surface of the recess, and receiving paint from the paint cartridge through the opening;
(iii) a cleaning liquid supply passage that receives a cleaning liquid from the outside and guides the cleaning liquid to an upper end portion of the paint path;
(iv) a seal ring disposed on a bottom surface of the recess and provided on an outer peripheral portion of an upper end opening of the paint passage,
By providing the electrostatic coating machine, wherein the lower end surface of the sleeve is pressed against the seal ring by the spring force of the first spring when the paint cartridge is mounted on the main body of the coating machine. Achieved.

  According to the cartridge type electrostatic coating machine of the present invention, at the time of color change, the paint passage in the coating machine main body is cleaned in a state where the paint cartridge is mounted on the coating machine main body. That is, in the electrostatic coating machine of the present invention, the paint in the paint cartridge is supplied to the main body of the paint machine through the paint outlet constituted by the sleeve. The connection portion between the outlet of the paint cartridge and the upper end opening of the paint passage of the coating machine body is sealed by the seal ring. Therefore, it is possible to prevent the paint from the paint cartridge from contaminating the connection portion between the paint cartridge and the coating machine main body. Also, when changing colors, after closing the paint on-off valve of the paint cartridge and introducing the cleaning liquid from the outside into the main body of the coating machine, the cleaning liquid that has entered the main body of the coating machine is specified by the seal ring. It is possible to clean the paint passage in the main body of the coating machine including the vicinity of the outlet of the paint cartridge.

  In a preferred embodiment of the present invention, the paint on-off valve of the paint cartridge includes a fixed valve seat formed at a lower end of the sleeve, a movable valve body seated on the fixed valve seat, and the movable valve body as the fixed valve. And a second spring that is biased toward the seat. The paint on-off valve can be forcibly opened by pushing up the movable valve body with a push rod that advances from the coating machine main body side. Conversely, the paint on-off valve can be closed by retracting the push rod. As a modification, an actuator for opening and closing the paint opening / closing valve of the paint cartridge may be incorporated in the paint cartridge.

  The paint cartridge according to the present invention does not include the feed tube used in the conventional paint cartridge. Therefore, it becomes easy to provide a trigger valve comprising an on-off valve in the paint passage of the coating machine body. The opening and closing of the trigger valve is executed in synchronization with the coating start timing and end timing. Therefore, it is possible to synchronize the start and end of spraying of the paint of the electrostatic coating machine with the start and end timing of the coating process.

  The electrostatic coating machine of the present invention can employ any type of paint cartridge. Specifically, the paint cartridge may be a piston type cartridge that extrudes paint by a piston, or may be a bag type cartridge that extrudes paint by crushing a paint bag. Alternatively, a paint cartridge in which the paint storage chamber of the paint cartridge is formed of a stretchable film may be employed (membrane pump type cartridge).

  Other objects and operational effects of the present invention will become apparent from the following description of preferred embodiments of the present invention.

It is the schematic of the electrostatic coating machine provided with the bag type coating material cartridge of the Example attached to the coating robot, and is a figure which shows the coating process of an electrostatic coating machine. It is a front view of the paint bag accommodated in the paint cartridge of FIG. FIG. 3 is a cross-sectional view of the bag body taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view of the upper end opening along the line IV-IV in FIG. 2. It is detail drawing of the one-way valve provided in the lower end of the paint channel | path which leads to the lower end opening part of the paint bag of a paint cartridge, and shows the state which fixed the paint cartridge to the coating machine main body. It is a figure corresponding to FIG. 5, and is a figure which shows the state which forcedly opened the one-way valve provided in the lower end of the coating material path of a coating material cartridge with the actuator with a push rod by the side of a coating machine main body. It is a detailed view of an actuator with a push rod for forcibly opening a one-way valve provided at the lower end of a hydraulic fluid supply passage that leads to a sealed space of a paint cartridge. FIG. 8 is an enlarged view of a main part extracted from the main part of FIG. 7, for explaining that the one-way valve of the hydraulic fluid supply passage of the paint cartridge can be forcibly opened by a push rod. It is a figure for demonstrating the process of wash | cleaning the coating-material supply channel | path of a coating machine main body, after using up the coating material of a coating-material cartridge, with this coating-material cartridge mounted | worn. It is a figure for demonstrating the process which fixes the empty coating material cartridge removed from the coating machine main body to the predetermined position of a coating material bag washing | cleaning station, and wash | cleans the inside of a coating material bag after washing | cleaning of the coating device body was completed. It is a figure for demonstrating the process of filling a coating material bag with a coating material after wash | cleaning a coating material cartridge. It is a figure for demonstrating the modification of the washing | cleaning method of a coating material cartridge, and is a figure for demonstrating the modification of a coating material bag. It is a figure for demonstrating the washing | cleaning method of the coating material cartridge provided with the hydraulic fluid bag which can apply this invention. It is a figure for demonstrating the other washing | cleaning method of the coating material cartridge provided with the hydraulic fluid bag which can apply this invention. It is a figure for demonstrating that this invention is applicable also to washing | cleaning of a piston-type paint cartridge.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram for explaining an outline of an electrostatic coating machine mounted on a coating robot. In FIG. 1, reference numeral 1 denotes an arm of a painting robot, and an electrostatic painting machine 2 is attached to the tip of the robot arm 1. The electrostatic coating machine 2 exemplarily shows a rotary atomizing type coating machine provided with a bell cup 4 as a paint atomizing means, but the present invention is preferably applied to a spray type. Can do.

  The electrostatic coating machine 2 is a paint cartridge type coating machine. Specifically, the electrostatic coating machine 2 includes a coating machine body 6 fixed to the tip of the robot arm 1 and a paint cartridge mounted on the upper end surface of the coating machine body 6, that is, the surface opposite to the bell cup 4. 10 and. The paint cartridge 10 is detachable from the coating machine body 6.

  The paint cartridge 10 has a paint bag 12 that constitutes a paint storage chamber for filling the paint. By applying pressure from the outside to the paint bag 12 to crush the paint bag 12 and forcibly reducing the volume of the paint storage chamber formed by the paint bag 12, the paint in the paint bag 12 is removed from the main body of the coating machine. 6 can be supplied.

  The paint cartridge 10 has a sealed space 14 in which the paint bag 12 is accommodated. The sealed space 14 is formed by an outer case 16. The outer case 16 is preferably made of a transparent or translucent rigid material and is typically made of a transparent or translucent plastic material.

  The paint cartridge 10 is a cartridge that applies pressure directly to the paint bag 12 with hydraulic fluid. Therefore, the periphery of the paint bag 12 is filled with the working fluid. An insulating liquid is suitably employed as the working fluid, and typically an insulating thinner is used as the working fluid. Since it is not desirable for air to enter the hydraulic fluid in the sealed space 14 constituting the hydraulic fluid chamber, in order to capture the air in the sealed space 14, the sealed space 14 has a convex air reservoir at the top. 14a is preferably provided.

  FIG. 2 is a front view of the paint bag 12. The paint bag 12 is a cylindrical flexible plastic molded product opened up and down. Specifically, referring to FIG. 2, the paint bag 12 includes a cylindrical bag main body 12a extending vertically, an upper end opening 12b extending upward from the upper end of the bag main body 12a, and a lower end of the bag main body 12a. And a lower end opening 12c extending downward. That is, the paint bag 12 is opened up and down through the upper and lower mouth portions 12b and 12c. The paint bag 12 has an upper end 12 b and a lower end 12 c fixed to the paint cartridge 10, and the bag body 12 a is crushed laterally by the hydraulic fluid supplied to the sealed space 14. The bag body 12a of the paint bag 12 is formed in a shape in which a corner portion between the upper end opening 12b and the lower end opening 12c is smoothly curved.

  By the way, the currently implemented paint bag is made by thermally welding two thin flexible sheets, and the paint easily adheres to the inner surface of the paint bag, and the amount of paint remaining in the paint bag. It can be said that there was no consideration regarding the reduction of the amount as much as possible. As can be seen from this, in the conventional bag-type paint cartridge, the idea of filling and reusing the same color paint is stopped, and the idea of cleaning the inside of the paint bag for reuse It can be said that there was no.

  The paint bag 12 of the embodiment is a molded product made of a flexible synthetic resin material manufactured using a mold, and the inner surface of the paint bag 12 is configured as a seamless and smooth surface. In the paint bag 12 of this embodiment, low molecular polyethylene is adopted as the material, and this is because the low molecular polyethylene is a suitable material for making a thin and flexible bag by blow molding. . The low molecular polyethylene is a resin material having durability required for cleaning the inside of the paint bag 12 and reusing the paint bag 12 many times.

  Of course, the material and molding method of the paint bag 12 are not limited to the low molecular polyethylene and blow molding described above. To reduce the amount of paint to be discarded at the time of internal cleaning and washing of the coating material bag 12 to the limit, as the characteristics of the coating material bag 12, (1) adequate flexibility of at least the bag body 12a, (2) the inner surface of the water repellent, (3) It should have a seamless and smooth inner surface. Therefore, as long as this condition is satisfied, the molding method and the resin material of the paint bag 12 can be arbitrarily selected. Further, the inner surface of the paint bag 12 may be treated to impart water repellency, seamlessness and smoothness to the inner surface of the paint bag 12. For example, nylon resin or fluororesin-based FEP is a resin material excellent in chemical resistance and self-lubricating property, but the paint bag 12 may be made using these resins. Further, for example, the inner surface of the paint bag 12 may be coated with an FEP material. Examples of the method for treating the inner surface of the paint bag 12 include a coating method, a lining method, and a resin vapor deposition method. Moreover, a coating layer can also be formed on the inner surface of the paint bag 12 by immersing the paint bag 12 in a liquid of an appropriate resin material.

  As described above, the paint bag 12 of FIG. 2 is designed to push the paint from the lower end opening 12c when the bag body 12a is crushed in the lateral direction. If necessary to improve the crushing characteristics of the bag body 12a, as shown in phantom lines in FIGS. 2 and 4, the bag body 12a is integrated with a single or a plurality of vertically elongated ridges 12d extending in the longitudinal direction. You may shape | mold.

  As for the paint bag 12 which comprises a paint storage chamber, it is good that at least the bag main body 12a is transparent or translucent. When the bag body 12a is transparent or translucent, there is an advantage that the color of the paint in the bag body 12a and the filling amount of the paint can be visually confirmed from the outside. In addition, it becomes easy to detect that the paint bag 12 is damaged and the paint leaks out. This advantage is based on the premise that the outer case 16 forming the hydraulic fluid chamber (sealed space 14) is transparent or translucent.

  FIG. 3 shows the cross-sectional shape of the main body 12a, and FIG. 4 shows the cross-sectional shape of the upper end opening 12b. The upper end opening 12b has a circular cross section, and although not shown, the lower end opening 12c similarly has a circular cross section. These upper end opening 12b and lower end opening 12c are fixed to the coating material cartridge 10.

  Returning to FIG. 1, the coating material cartridge 10 has first to fourth internal passages 20, 22, 24, and 26. The first internal passage 20 is a paint passage that communicates with the lower end opening 12 c of the paint bag 12. The second internal passage 22 is a hydraulic fluid supply passage that communicates with the lower end of the sealed space 14 constituting the hydraulic fluid chamber. The third internal passage 24 is a cleaning liquid supply passage that communicates with the upper end opening 12 b of the paint bag 12. The fourth internal passage 26 is a hydraulic fluid discharge passage communicating with the upper end (the air reservoir 14a) of the sealed space 14.

  The first to fourth internal passages 20 to 26 are opened on the lower surface of the paint cartridge 10. The lower surface of the paint cartridge 10 constitutes a contact surface for the paint machine body 6 when the paint cartridge 10 is mounted on the paint machine body 6.

  Check valves 30, 32, 34, and 36 that function as on-off valves are assembled in the first to fourth internal passages 20 to 26, respectively. In FIG. 1, the first to fourth check valves 30 to 36 are illustrated at positions away from the lower surface of the paint cartridge 10, but this is due to drawing reasons. The check valves 30, 32, 34, and 36 are actually disposed adjacent to the lower surface of the paint cartridge 10. The first to fourth check valves 30 to 36 functioning as on-off valves are composed of a fixed valve seat and a spring-biased movable valve body. Since such a check valve is well known in the art, a detailed description thereof is omitted, but a specially designed check valve is adopted as the first check valve 30 of the first internal passage (paint passage) 20. ing. The first check valve 30 will be described in detail later with reference to FIGS. 5 and 6.

  With reference to FIG. 1, the coating machine body 6 and the robot arm 1 will be described. The coating machine body 6 has a recess 40 formed on the upper end surface thereof, that is, the surface opposite to the bell cup 4, and the coating cartridge 10 is received by the recess 40. When the paint cartridge 10 is received in the recess 40, the paint cartridge 10 is fixed to the coating machine main body 6 by the lock mechanism 42 operated by air.

  The coating machine body 6 has a paint supply passage 44 that supplies the paint received from the paint cartridge 10 to the bell cup 4, and a trigger valve 46 is interposed in the paint supply passage 44. The trigger valve 46 is an open / close valve that opens and closes by pilot air. In the figure, reference numeral 48 is an air motor, and the bell cup is rotationally driven by the air motor 48.

  JP 11-262699 A discloses a piston type paint cartridge similar to those of Patent Documents 1 to 3, and discloses a paint cartridge with a feed tube. FIG. 5 of JP-A-11-262699 shows details of a valve mechanism that opens and closes the tip (lower end) opening of the feed tube. The valve mechanism at the tip (lower end) of the feed tube corresponds to the trigger valve 46 described above. However, the valve mechanism disclosed in JP-A-11-262699 has a piston rod of an air cylinder built in the coating machine body. The piston rod is inserted from the upstream end of the feed tube, and extends over the entire length of the feed tube. And the needle valve mechanism is comprised by the front-end | tip part (lower end part) of a piston rod, and the front-end | tip part (lower end part) of a feed tube. This needle valve mechanism corresponds to the trigger valve 46 included in the embodiment of the present invention.

  On the other hand, in the embodiment of the present invention, since the paint cartridge 10 without the feed tube is employed, the paint supply passage 44 of the coating machine body 6 is air-driven as a paint opening / closing valve inside the coating machine body 6. A simple configuration in which a trigger valve 46 of the type is interposed can be employed.

  The coating machine main body 6 has a hydraulic fluid supply passage 50 that supplies hydraulic fluid to the paint cartridge 10, and the hydraulic fluid supply passage 50 in the coating machine main body communicates with an in-arm hydraulic fluid supply passage 52 of the robot arm 1. ing.

  The hydraulic fluid supply passage 52 of the robot arm 1 will be described. The in-arm hydraulic fluid supply passage 52 includes a pump 56 that supplies hydraulic fluid supplied from the hydraulic fluid source 54 to the paint cartridge 10 under pressure. The pump 56 is mounted on the robot arm 1. The pump 56 is preferably a gear pump capable of precise flow rate control, for example. The hydraulic fluid supplied under pressure from the pump 56 is supplied to the paint cartridge 10 by operating the passage switching valve 58 provided in the robot arm 1 or the coating machine body 6, or the hydraulic fluid through the reflux passage 60. Returned to source 54. The hydraulic fluid of the hydraulic fluid source 54 is an insulating liquid (typically an insulating thinner). As a modification, the pump 56 is not installed in the robot arm 1 but is installed outside the painting robot, and the supply of hydraulic fluid to the coating material cartridge 10 is controlled in the robot arm 1 or the coating machine body 6 to switch the passage. It may be performed by the valve 58.

  The robot arm 1 incorporates a high voltage generator 62 in addition to the pump 56 (gear pump). The high voltage generated by the high voltage generator 62 is applied to the bell cup 4. Of course, the high voltage generator 62 may be built in the coating machine body 6.

  In FIG. 1, reference numeral 64 indicates an air vent passage for extracting air mixed in the working fluid (insulating thinner). The air vent passage 64 is connected to the main body of the coating machine via an opening / closing valve 66 driven by air. The internal hydraulic fluid supply passage 50 is connected. By opening the on-off valve 66 from time to time, the hydraulic fluid in the coating machine main body hydraulic fluid supply passage 50 and the hydraulic fluid supply passage 52 in the arm is returned to the hydraulic fluid source 54, The air mixed in the arm hydraulic fluid supply passage 52 can be discharged.

  It should be noted that the coating machine body 6 has a cleaning liquid supply passage 70. One end of the cleaning liquid supply passage 70 is connected to the paint supply passage 44 at a position adjacent to the upstream end of the above-described paint supply passage 44 in the main body of the coating machine, that is, the cartridge receiving recess 40. The other end (upstream end) of the cleaning liquid supply passage 70 in the coating machine main body is open to the side surface of the upper end portion of the coating machine main body 6, and a fifth check valve 72 is disposed in this opening portion. Yes. The fifth check valve 72 includes a conventionally known fixed valve seat and a spring-biased movable valve body.

  Secondly, the sprayer body 6 has two actuators 74, 76 with push rods adjacent to the cartridge receiving recess 40, and the first and second actuators 74, 76 are Driven by air. The push rod 74a (FIG. 6) of the first actuator 74 acts on the first check valve 30 (paint passage) of the paint cartridge 10 to forcibly open the first check valve 30. The push rod 76a of the second actuator 76 acts on the second check valve 32 (operating fluid supply passage) of the paint cartridge 10 to forcibly open the second check valve 32 (FIG. 8).

  5 and 6 show the first check valve 30 of the paint cartridge 10. As described above, the first check valve 30 is interposed in the first internal passage 20 through which the paint discharged from the paint bag 12 passes. Referring to FIGS. 5 and 6, the coating material cartridge 10 has a stepped sleeve 300 that protrudes downward from its lower end surface and can be displaced up and down, and a first reverse is provided at the lower end of the movable sleeve 300. A valve seat 302 of the stop valve 30 is formed. The movable valve body 304 seated on the valve seat 302 is urged in the direction (downward) in which the movable valve body 304 is seated on the valve seat 302 by an inner circumferential spring 306. On the other hand, the stepped sleeve 300 is urged downward by an outer peripheral spring 308. A receiving member 310 that protrudes downward is formed on the lower end surface of the movable valve body 304, and the receiving member 310 protrudes downward from the stepped sleeve 300. The push rod 74a of the first actuator 74 described above abuts on the receiving member 310 and pushes it up, thereby forcibly opening the first check valve 30 employed as an on-off valve (FIG. 6).

  The recess 40 of the coating machine body 6 is formed with a second recess 402 for receiving the lower end portion of the stepped sleeve 300, that is, the small diameter portion 300 a, and the central portion of the second recess 402. In addition, a paint supply passage 44 on the coating machine side is opened. That is, the paint supply passage 44 is open at the center of the bottom surface of the second recess 402. A seal ring 404 is disposed on the outer periphery of the opening of the paint supply passage 44 on the bottom surface of the second recess 402.

  5 and 6 show a state in which the coating material cartridge 10 is positioned in the recess 40 of the coating machine body 6 and the coating material cartridge 10 is fixed to the coating machine body 6 by the locking means 42 (FIG. 1). Note that a seal ring 404 is interposed between the lower end surface of the stepped sleeve 300 and the bottom surface of the second recess 402. Since the stepped sleeve 300 of the paint cartridge 10 is urged downward by the outer peripheral spring 308, by fixing the paint cartridge 10 to the coating machine main body 6, the lower end surface of the stepped sleeve 300 is pressed against the seal ring 404 It will be in the state. Since the connecting portion between the first internal passage (paint passage) 20 of the paint cartridge 10 and the paint supply passage 44 of the coating machine main body 6 is sealed by the seal ring 404, the paint discharged from the paint cartridge 10 is applied. It is possible to prevent the recesses 40 and 402 from being contaminated by going around the cartridge receiving recess 40 and the second recess 402 of the machine body 6.

  FIG. 5 shows a state where the first check valve 30 of the paint cartridge 10 exhibits the function of a stopper valve. In the state of FIG. 5, the first check valve 30 performs the function of the original check valve. Thus, the paint is prevented from flowing out from the paint cartridge 10 (the paint passage 20 in the cartridge is closed).

  On the other hand, FIG. 6 shows a state in which the first check valve 30 is forcibly opened by forcibly pushing up the movable valve body 304 of the first check valve 30 by the push rod 74a. As described above, the push rod 74a is operated by the first actuator 74 installed in the coating machine body 6 in relation to the first check valve 30. The first actuator 74 is driven by air. In the forced open state shown in FIG. 6, since the movable valve body 304 of the first check valve 30 employed as the on-off valve is separated from the valve seat 302, the paint in the paint bag 12 has its lower end opening 12c. Can flow out from the paint cartridge 10 through the paint passage 20 in the cartridge (the paint passage 20 in the cartridge is opened).

  As described above, the paint cartridge 10 has the sleeve 300 that can be displaced up and down, and this sleeve 300 constitutes an outlet portion through which the paint of the paint bag 12 that constitutes the paint storage chamber flows out. It protrudes and is arrange | positioned below from the lower surface of this. A first check valve 30 is provided at the lower end of the sleeve 300. Further, the movable sleeve 300 is urged downward by the outer peripheral spring 308. On the other hand, the coating machine body 6 has a second recess 402 that receives the small diameter portion 300a of the sleeve 300, and the upper end of the paint supply passage 44 of the coating machine body 6 is located at the center of the bottom surface of the second recess 402. An opening is provided, and a seal ring 404 is disposed around the opening.

  When the paint cartridge 10 is assembled to the coating machine body 6, the lower end surface of the spring-biased movable sleeve 300 (small diameter portion 300 a) is pressed against the seal ring 404, whereby the sleeve 300 constituting the paint outlet of the paint cartridge 10. Then, the paint transition passage between the paint machine main body 6 and the paint supply passage 44 is sealed by the seal ring 404. Thereby, it can prevent that the coating material which came out of the coating material cartridge 10 contaminates the wall surface etc. of the 2nd recessed part 402. FIG.

  With the above configuration, the paint supply passage 44 of the coating machine body 6 can be cleaned while the paint cartridge 10 is mounted. This advantage is not limited to the bag-type paint cartridge 10 of the embodiment, and the same applies to a conventionally known piston-type paint cartridge and a paint cartridge employing the membrane pump disclosed in Patent Document 7, and accordingly, In the case of a paint cartridge of a piston type or a membrane pump type, particularly if the paint cartridge has a configuration in which the feed tube is omitted, the above-described structure has a great advantage.

  FIGS. 7 and 8 show details of the second actuator 76 provided in the coating machine body 6 for forcibly opening the second check valve 32 of the second internal passage (working fluid supply passage) 22 of the paint cartridge 10. FIG. The second actuator 76 advances and retracts the push rod 76a by taking in and out air, and the push rod 76a moves forward to forcibly separate the movable valve body 320 of the second check valve 32 from the valve seat 322 ( FIG. 8). Although this point is the same as the first actuator 74 and the first check valve 30 described above, a characteristic structure is adopted for the second actuator 76 with the push rod 76a in the following points.

  That is, the push rod 76a of the second actuator 76 of the coating machine body 6 not only has a function of forcibly separating the movable valve body 320 of the second check valve 32 from the valve seat 322 at its upper end surface (see FIG. 8) The push rod 76a constitutes a part of an on-off valve mechanism that opens and closes the hydraulic fluid supply passage 50 of the coating machine body 6.

  Referring to FIG. 7, the push rod 76a is surrounded by a sleeve 500 that constitutes an outlet portion (a hydraulic fluid outlet portion facing the cartridge receiving recess 40) of the hydraulic fluid supply passage 50 in the coating machine body. A valve seat 502 is formed on the inner peripheral surface of the upper end portion of 500. On the other hand, the push rod 76a is formed with a valve body 504 bulging in the radial direction at its upper end. The valve seat 502 and the valve body 504 constitute an open / close valve mechanism 506 that opens and closes the outlet portion of the hydraulic fluid supply passage 50 of the coating machine body 6.

  7, when the push rod 76a is displaced upward in FIG. 7, the valve body 504 integrated with the push rod 76a is separated from the valve seat 502 and is opened. As described above, when the push rod 76a is displaced upward, the second check valve 32 of the paint cartridge 10 is forcibly opened (arrow in FIG. 8).

  When the push rod 76a is displaced downward, the valve body 504 is seated on the valve seat 502, and the on-off valve mechanism 506 is closed. Of course, the second check valve 32 of the coating material cartridge 10 functions as the original check valve by the backward movement of the push rod 76a. It is possible to prevent the hydraulic fluid from leaking from 10.

  A flange 78 is fixed to the base end portion (lower end portion in FIG. 7) of the push rod 76 a, and the flange 78 is urged downward by a spring 80. Therefore, the push rod 76a is always spring-biased downward, and as a result, the on-off valve mechanism 506 is biased by the spring 80 in the valve closing direction.

  With the above configuration, the process in which the paint cartridge 10 is attached to the coating machine main body 6, and even if the paint cartridge 10 is fixed to the coating machine main body 6, it operates from the coating machine main body 6 unless the second actuator 76 is operated. Liquid (insulating thinner) will not leak. Of course, also in the paint cartridge 10, the second check valve 32 prevents the working fluid (insulating thinner) from leaking out from the sealed space 14 (working fluid chamber).

  Returning to FIG. 1, the operation of the electrostatic coating machine 2 in the painting process will be described with reference to FIG. The painting process, the first and second actuators 74, 76 is operated pushrod 74a, 76a moves forward, the push rod 74a, the first by advancement of the 76a, the second check valve 30, 32 force It is maintained in an open state (both the in-cartridge paint passage 20 and the in-cartridge hydraulic fluid supply passage 22 are open).

(1) The first check valve 30 (the paint passage in the cartridge) is forcibly opened;
(2) The second check valve 32 (working fluid supply passage in the cartridge) is forcibly opened.

  The amount of hydraulic fluid (insulating thinner) supplied to the paint cartridge 10 can be controlled by ON / OFF control of the gear pump 56 or by controlling the passage switching valve 58. Then, by applying pressure to the paint bag 12 with the hydraulic fluid supplied to the paint cartridge 10, the paint can be discharged from the paint bag 12 in a controlled state. The ON / OFF operation of the gear pump 56 and the passage switching operation of the passage switching valve 58 are performed in synchronization with the opening / closing of the trigger valve 46 of the coating machine body 6. Thereby, the precision of control of the supply start and supply stop of the paint to the bell cup 4 can be enhanced.

  At the time of a predetermined coating is completed, in a state where the coating material bag 12 constituting the paint chamber is completely crushed, the interior volume of the coating material bag 12 (paint chamber) at this time is minimal, therefore the paint The amount of paint remaining in the bag 12 is extremely small compared to a conventional piston type paint cartridge.

  When performing the color change of the electrostatic coating machine 2, before replacing the paint cartridge 10 of a different color of paint to remove the paint cartridge 10 from the coating machine main body 6, the coating machine main body while wearing the paint cartridge 10 6 The paint supply passage 44 and the bell cup 4 are cleaned.

  FIG. 9 shows a cleaning process of the paint supply passage 44 and the bell cup 4 of the coating machine body 6. In this cleaning process, cleaning is performed with the used paint cartridge 10 mounted on the coating machine body 6. In the cleaning process, the operations of the first and second actuators 74 and 76 are released, and the push rods 74a and 76a are retracted. As a result, the first and second check valves 30 and 32 become the original check valves. The function is performed to close the in-cartridge paint passage 20 and the hydraulic fluid supply passage 22.

  A cleaning nozzle 84 is inserted into the cleaning liquid supply passage 70 opened on the side surface of the coating machine body 6. When the cleaning nozzle 84 is inserted into the inlet of the cleaning liquid supply passage 70, the fifth check valve 72 disposed at the inlet of the cleaning liquid supply passage 70 is forcibly opened by the cleaning nozzle 84. By operating the external passage switching valve 86, the cleaning liquid or air is supplied from the cleaning nozzle 84 to the cleaning liquid supply passage 70 under pressure. Prior to the supply of the cleaning liquid or air, the trigger valve 46 provided in the coating machine main body paint supply passage 44 is opened. Further, the bell cup 4 is driven to rotate with the start of the supply of the cleaning liquid from the cleaning nozzle 84.

The state of each valve in the cleaning process of the paint supply passage 44 in the coating machine main body is as follows.
(1) Release of forced opening of the first check valve 30 (paint) (normal check valve function);
(2) Release of forced opening of the second check valve 32 (hydraulic fluid supply) (normal check valve function);
(3) The fifth check valve 72 (cleaning liquid in the main body of the coating machine) is forcibly opened by the cleaning nozzle 84;
(4) The trigger valve 46 is opened;
(5) The bell cup 4 rotates.

  When the cleaning liquid or air is supplied from the cleaning nozzle 84 under pressure, the cleaning liquid or air flows into the coating machine main body paint supply path 44 through the cleaning liquid supply path 70 of the coating machine main body 6, and passes through the paint supply path 44. It is discharged from the bell cup 4 through. The paint supply passage 44 and the bell cup 4 in the main body of the coating machine are purified by the flow of the cleaning liquid or air. Typically, cleaning liquid and air are alternately supplied from the cleaning nozzle 84 to the coating machine body 6.

  Cleaning liquid supply passage 70 has its downstream end, since it is connected to the upstream end of the coating machine main body paint supply passage 44 (upper portion) as described above, the cleaning liquid or air to flow into the paint supply passage 44, It reaches the tip of the first check valve 30 that protrudes from the lower end of the paint cartridge 10 to purify the tip of the first check valve 30. Since the first check valve 30 performs the function of the original check valve and closes the paint passage 20 in the cartridge (FIG. 5), the paint passage 20 in the cartridge and the paint supply passage 44 in the coating machine main body are the first. 1 is in a state of being separated by the check valve 30. Therefore, the first check valve 30 can prevent the cleaning liquid from entering the paint bag 12. The cleaning liquid is typically thinner, but it may be cleaning water obtained by adding a surfactant to water.

  In addition, a seal ring 404 in which the distal end surface of the sleeve 300 is in pressure contact is interposed between the sleeve 300 incorporating the first check valve 30 and the second recessed portion 402 receiving the lower end small diameter portion 300a of the sleeve 300. (Fig. 5), the paint transition passage defined by the seal ring 404 is also cleaned by the cleaning liquid or air, but the entire wall surface of the second recess 402 is cleaned by the cleaning liquid containing the paint. Can be prevented from being contaminated. Therefore, not only the coating material supply passage 70 of the coating machine body 6 but also the connecting portion with the coating material cartridge 10 can be cleaned by the cleaning liquid. Furthermore, the tip of the sleeve 300 that constitutes the paint outlet of the paint cartridge 10 can also be cleaned. This is a notable advantage not seen in the past. Of course, the configuration that provides this advantage is not limited to a bag-type paint cartridge as a general theory, but can also be applied to a piston-type paint cartridge and a membrane pump-type cartridge. Regarding the cleaning of the bell cup 4, if necessary, a cleaning liquid may be sprayed on the bell cup 4 from the outside. When the cleaning of the coating machine body 6 is completed, air is finally supplied from the cleaning nozzle 84 to the coating machine body 6, thereby removing the cleaning liquid adhering to the paint supply passage 44 and the bell cup 4 in the coating machine body. The

  When the cleaning of the coating machine body 6 is completed, the paint cartridge 10 mounted on the coating machine body 6 is then replaced. Since the cleaning of the coating machine main body 6 and the cleaning of the seal ring 404 are completed, the painting can be resumed only by mounting the coating material cartridge 10 filled with the paint of another color on the coating machine main body 6.

  The coating material cartridge 10 removed from the coating machine main body 6 is subjected to cleaning of the coating material bag 12. FIG. 10 is a view for explaining the paint bag cleaning step. The used paint cartridge 10 is positioned at a predetermined position of the bag cleaning station 88. This positioning is the same as the positioning with respect to the coating machine body 6. When the paint cartridge 10 is positioned at a predetermined position, the paint cartridge 10 is fixed by the lock mechanism 90.

  The bag cleaning station 88 is provided with actuators 880, 882, 884, 886 having first to fourth push rods corresponding to the first to fourth check valves 30, 32, 34, 36 of the paint cartridge 10. Has been. The first to fourth actuators 880 to 886 with push rods exhibit substantially the same function as the first and second actuators 74 and 76 with push rods of the coating machine body 6 described above. Detailed description thereof will be omitted.

  The paint bag 12 of the original paint cartridge 10 installed at the bag cleaning station 88 is in a crushed state. Cleaning of the coating material bag 12 constituting the paint chamber is, (i) to expand the coating material bag 12 to expand the volume of the paint chamber and to reduce the volume of the paint chamber by crushing the (ii) the coating material bag 12 The cleaning liquid and air are put into the paint bag 12 with the operation of, and the cleaning liquid and air are discharged. The “expansion and crushing” of the paint bag 12 may be set as one set, and may be completed once or repeated a plurality of times. Of course, if necessary, prior to cleaning the paint bag 12, the paint bag 12 may be crushed to the maximum to recover the paint remaining in the paint bag 12 to the maximum.

The states of the on-off valves, that is, the check valves 30, 32, 34, and 36 in the paint bag expansion process are as follows.
(1) Release of forced opening of the first check valve 30 (paint) (normal check valve function);
(2) Release of forced release of the second check valve 32 (hydraulic fluid supply) (normal check valve function);
(3) The third check valve 34 (cleaning liquid supply) is forcibly opened;
(4) The fourth check valve 36 (hydraulic fluid discharge) is forcibly opened.

  As shown in FIG. 10, an air source and a cleaning liquid source (thinner or water) are installed in the bag cleaning station 88, and air and cleaning liquid are supplied from the air source and the cleaning liquid source. Switching between air and cleaning liquid is performed by a passage switching valve 888. Air and cleaning liquid are alternately supplied to the paint bag 12 through the third internal passage (cleaning liquid supply passage) 24 of the paint cartridge 10 through the passage switching bubble 888. As described above, the first check valve 30 at the outlet (the lower end opening 12c) of the paint bag 12 exhibits the function of a normal check valve and is in a state in which the paint passage 20 is closed. The paint bag 12 is expanded by supplying air or paint from the third internal passage (cleaning liquid supply passage) 24 of the paint cartridge 10 to the inside of the paint bag 12 through the upper end opening 12 b of the paint bag 12. Accordingly, the hydraulic fluid filling the sealed space 14 constituting the hydraulic fluid chamber of the paint cartridge 10 is forced from the paint cartridge 10 through the fourth internal passage 26 (operating fluid discharge passage) opened to the air reservoir 14a. And passively extruded. The hydraulic fluid discharged from the paint cartridge 10 is collected in the hydraulic fluid source.

The following example can be given as a specific method for cleaning the paint bag 12.
First step (Paint bag expansion step): Air is supplied to the paint bag 12 through the third internal passage (cleaning liquid supply passage) 24 to expand the paint bag 12, and the internal volume of the paint bag 12 is increased to a substantially maximum value. Enlarge. Thereby, the main body 12a of the paint bag 12 can be made into a state without a wrinkle. The first check valve 30 (paint) is in a closed state.
Second step (cleaning liquid supply step): The cleaning liquid is supplied to the paint bag 12 and the cleaning liquid is caused to flow along the inner surface of the paint bag 12 to clean the paint bag 12. The first check valve 30 (paint) is in a closed state.
Third Step (Paint Bag Crushing Step): The paint bag 12 is crushed, the internal volume of the paint bag 12 is reduced, and the cleaning liquid of the paint bag 12 is discharged.
If necessary, the second and third steps are repeated.

The states of the on-off valves (check valves 30, 32, 34, 36) in the third step (crushing step) of the paint bag 12 are as follows.
(1) The first check valve 30 (paint) is forcibly opened;
(2) The second check valve 32 (hydraulic fluid supply) is forcibly opened;
(3) Forcible opening of the third check valve 34 (cleaning liquid supply) is canceled (normal check valve function);
(4) The forcible opening of the fourth check valve 36 (hydraulic fluid discharge) is canceled (normal check valve function).

  A gear pump 890 is installed in the bag cleaning station 88 as shown in FIG. In the third step (crushing step), the amount of hydraulic fluid controlled by the gear pump 890 is supplied to the paint cartridge 10 under pressure. When hydraulic fluid in the closed space 14 (hydraulic fluid chamber) of the paint cartridge 10 enters, the coating material bag 12 is crushed by hydraulic fluid, air and wash the paint bag 12 is pushed out to the outside through the lower opening 12c. Reference numeral 892 in FIG. 10 indicates a waste liquid tank, and the cleaning liquid discharged from the paint bag 12 is stored in the waste liquid tank 892.

  As described above, (enlargement of the internal volume of the coating material bag 12) extended in the coating material bag 12, a crushing (reduction of the inner volume of the coating material bag 12) as a set, the repetition of the coating material bag 12 which one or more times The inside is cleaned. Finally, air is introduced into the paint bag 12 and the cleaning liquid adhering to the inside of the paint bag 12 is discharged, whereby the cleaning process of the paint bag 12 is completed. At the stage where the cleaning process of the paint bag 12 is completed, the paint bag 12 is in a crushed state (in which the internal volume of the paint bag 12 is minimum).

  After the paint bag 12 has been cleaned, the paint bag 12 is then filled with paint. FIG. 11 is a diagram for explaining the paint filling process. The washed paint cartridge 10 is positioned at a predetermined position of the paint filling station 92. This positioning is the same as that of the coating machine body 6 and the bag cleaning station 88. When the paint cartridge 10 is positioned at a predetermined position, the paint cartridge 10 is fixed by the lock mechanism 94.

  Of the first to fourth check valves of the paint cartridge 10, the paint filling station 92 includes first and fourth check valves excluding the second check valve 32 related to hydraulic fluid supply and the third check valve 34 related to cleaning liquid supply. Actuators 920 and 922 with first and fourth push rods corresponding to the check valves 30 and 36 are provided. The first and fourth actuators 920 and 922 with push rods exhibit substantially the same function as the first and second actuators 74 and 76 with push rods of the coating machine body 6 described above. Detailed description thereof will be omitted.

The states of the on-off valves, that is, the check valves 30 and 36 in the paint filling process are as follows.
(1) The first check valve 30 (paint) is forcibly opened;
(2) The fourth check valve 36 (hydraulic fluid discharge) is forcibly opened.

  The paint filling station 92 and gear pump 96 is installed paint coating source to fill under pressure to the coating material bag 12, the lower end opening portion of the predetermined amount of coating material by controlling the gear pump 96 is the coating material bag 12 The paint bag 12 is filled through 12c. Instead of the flow rate control of the gear pump 96, the coating material bag When a flow meter for controlling the amount of paint supplied to the paint bag 12 under pressure from the pump, the amount of coating material measured by the flow meter reaches a predetermined value A combination with a flow rate control valve for stopping the supply of the paint to 12 may be adopted. Although the paint bag 12 is expanded by filling the paint, the working fluid filling the sealed space 14 is discharged to the outside through the air reservoir 14a and the fourth internal passage (working fluid discharge passage) 26, and is discharged. The collected hydraulic fluid is collected in the hydraulic fluid source.

  Of course, since the cleaning of the paint cartridge 10 is completed before the paint is filled, the color of the paint filled in the paint cartridge 10 is arbitrary. The paint cartridge 10 which has been filled with paint is stocked for the next painting.

  Having described the embodiments in the case of adopting an insulating thinner as the actuating fluid, when employing a conductive liquid such as water as the working fluid, by installing a voltage block mechanism to the robot arm 1, an electrostatic coating machine When a high voltage is applied to 2 (during the painting operation), it is preferable to electrically insulate by a voltage block mechanism.

The following example can be given as a modification of the above embodiment.
(1) The first to fourth check valves 30 to 36 built in the paint cartridge 10 may be constituted by air-driven on-off valves.
(2) In the above embodiment, the paint bag 12 includes the upper and lower mouth portions 12a and 12b. However, the paint bag 12 may be provided with only the lower end mouth portion 12b without the upper end mouth portion 12a ( FIG. 12). Reference numeral 896 shown in FIG. 12 indicates a passage switching valve. In FIG. 12, check valves 30 to 36 interposed in the paint cartridge passage leading to the paint bag 12 and the paint cartridge passage leading to the sealed space 14 (working fluid chamber) are not shown.

(3) In the embodiment of FIG. 1, a method of directly pressurizing the coating material bag 12 with the working fluid is adopted. However, as illustrated in FIG. 13, the working fluid bag 8 adjacent to the coating material bag 12 is used. It may be a paint cartridge provided with. The hydraulic fluid bag 8 forms a hydraulic fluid chamber, and the hydraulic fluid bag 8 is expanded by supplying the hydraulic fluid to the hydraulic fluid bag 8 to crush the paint bag 12.

(4) The hydraulic fluid bag 8 includes two upper and lower ports 8a and 8b, and the hydraulic fluid in the hydraulic fluid bag is discharged from the upper end port 8a, while the hydraulic fluid is discharged from the lower port 8b. The hydraulic fluid bag 8 may be expanded by supplying it to FIG.

(5) The hydraulic fluid bag 8 includes a single mouth portion 8b, and the hydraulic fluid is supplied to the hydraulic bag 8 through the single mouth portion 8b, and the hydraulic fluid is discharged from the hydraulic fluid bag 8. Good (FIG. 14). In FIG. 14, the check valve interposed in the paint cartridge passage leading to the paint bag 12 and the paint cartridge passage leading to the hydraulic fluid bag 8 is not shown.

(6) The vibration source 28 may be provided in the bag cleaning station 88, and the paint cartridge 10 being cleaned may be vibrated up and down and / or left and right by the vibration source 28 (FIG. 12).
(7) A rotary table 894 may be prepared at the bag cleaning station 88 (FIGS. 12 and 14), and the paint cartridge 10 may be fixed to the rotary table 894 so that the paint cartridge 10 being cleaned is rotated. In the figure, reference symbol O indicates a rotation center axis. This rotation may be a unidirectional rotation, but preferably, the forward rotation and the reverse rotation are alternately repeated.

  The embodiment of the present invention has been described by exemplifying the paint cartridge 10 provided with the paint bag 12, but the present invention can also be applied to a piston-type or membrane-piston-type paint cartridge. An example of the internal cleaning method of the piston type paint cartridge 130 will be described with reference to FIG.

  In FIG. 15, the illustrated paint cartridge 130 has a piston 132, a hydraulic fluid chamber 134 is formed above the piston 132, and a paint storage chamber 136 is formed below the piston 132. FIG. 15 (I) schematically shows an initial state in which the piston type paint cartridge 130 is positioned at the cleaning station. This cleaning station corresponds to the above-described bag cleaning station 88 (FIG. 10).

  First, by supplying hydraulic fluid to the hydraulic fluid chamber 134 of the paint cartridge 130, depress the piston 132 to the deepest of the paint chamber 136 to collect the paint remaining in the paint chamber 136 (in FIG. 10 step (II )). Next, a cleaning liquid is supplied to the paint chamber 136 to push up the piston 132 (step (III) in FIG. 10). Next, the hydraulic fluid is supplied to the hydraulic fluid chamber 134, the piston 132 is pushed down, and the cleaning liquid in the paint storage chamber 136 is discharged (step (IV) in FIG. 10). The degree of raising and lowering of the piston 132 in step (III) and step (IV) in FIG. 10 is arbitrary. For example, the piston 132 may be pushed up to the top, or the pushing of the piston 132 is stopped halfway. Alternatively, the process may proceed to the next discharging step (step (IV) in FIG. 10). In order to clean the paint storage chamber 136 while pushing up the piston 132, cleaning liquid and air may be alternately supplied to the paint storage chamber 136. Alternatively, the piston 132 may be pushed up to a certain height by air, and then the cleaning liquid may be supplied to the paint storage chamber 136. Thus, the combination of the supply mode of air and cleaning liquid is arbitrary, and may be determined by experiment.

  The above steps III and IV may be taken as a set, and this may be repeated once or a plurality of times. Further, as described with reference to FIG. 12, the paint cartridge 130 may be vibrated up and down or left and right or up and down and left and right during cleaning. Further, as described with reference to FIGS. 12 and 14, the paint cartridge 130 may be rotated during the cleaning. In FIG. 14, the paint cartridge passage leading to the hydraulic fluid chamber 134 and the paint chamber 136 of the paint cartridge 130 is check valve in the same manner as the paint cartridge 10 of the bag type described above is interposed, In FIG. 14, the illustration is omitted. As can be easily understood by those skilled in the art, the piston-type paint cartridge 130 also employs the hydraulic fluid discharge passage 26 described with reference to FIG. 1 and the like, and operates in the cartridge to supply the hydraulic fluid to the hydraulic fluid chamber 134. A liquid supply passage and an in-cartridge working fluid discharge passage for discharging the working fluid in the working fluid chamber 134 may be formed in the paint cartridge 130.

  The present invention can also be suitably applied to a paint cartridge that employs a membrane pump employed in Patent Document 8 (JP Utility Model Publication No. 04-87759).

  The present invention is applied to electrostatic coating. In particular, it is suitably applied to a painting robot.

1 Coating Robot Arm 2 Electrostatic Coating Machine 4 Bell Cup 6 Coating Machine Body 10 Paint Cartridge 12 Paint Bag (Paint Storage Room)
20 First internal passage (paint passage) of paint cartridge
30 First check valve (paint passage in the cartridge)
44 Paint passage in the coating machine main body 46 Trigger valve 70 Cleaning liquid supply passage 300 in the coating machine main body Sleeve 302 Fixed valve seat 304 at the lower end of the sleeve Movable valve body 306 Inner peripheral spring (move the movable valve body: second spring)
308 Peripheral spring (biasing sleeve: first spring)
402 Second recess 404 for receiving sleeve Seal ring

Claims (8)

In an electrostatic coating machine that includes a paint cartridge that can be attached to and detached from a coating machine main body, and the coating machine main body receives paint supplied from the paint cartridge and performs coating on a workpiece.
The paint cartridge is
(i) a sleeve constituting the paint outlet of the paint cartridge and displaceable up and down;
(ii) a first spring that biases the sleeve downward;
(iii) a paint opening / closing valve provided on the sleeve and opening / closing an outlet of the paint passage;
The coating machine body is
(i) a recess for receiving the sleeve;
(ii) a paint passage having an opening opened on a bottom surface of the recess, and receiving paint from the paint cartridge through the opening;
(iii) a cleaning liquid supply passage that receives a cleaning liquid from the outside and guides the cleaning liquid to an upper end portion of the paint path;
(iv) a seal ring disposed on a bottom surface of the recess and provided on an outer peripheral portion of an upper end opening of the paint passage,
An electrostatic coating machine, wherein when the paint cartridge is attached to the main body of the coating machine, a lower end surface of the sleeve is pressed against the seal ring by a spring force of the first spring. The paint on-off valve is
A fixed valve seat formed at the lower end of the sleeve;
A movable valve body seated on the fixed valve seat;
The electrostatic coating machine according to claim 1, further comprising: a second spring that biases the movable valve body toward the fixed valve seat.   The electrostatic coating machine of Claim 2 with which the actuator provided with the push rod which pushes up the movable valve body of the said coating material cartridge is incorporated in the said coating machine main body.   The electrostatic coating machine according to claim 1, wherein an actuator for opening and closing the paint opening / closing valve is built in the paint cartridge.   The electrostatic coating machine of Claim 1 with which the trigger valve which consists of an on-off valve is provided in the coating material channel | path of the said coating machine main body.   The electrostatic coating machine according to claim 1, wherein the paint cartridge is a piston type cartridge that extrudes paint by a piston.   The electrostatic coating machine according to claim 1, wherein the paint cartridge is a bag-type cartridge that extrudes paint by crushing a paint bag.   The electrostatic coating machine according to claim 1, wherein the coating material cartridge is a membrane pump type cartridge in which a coating material storage chamber is formed by a stretchable membrane.

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