JP2014069170A - Electrostatic coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic coating apparatus that can shorten a filling time even if a color is changed, and can reduce the cost of equipment.SOLUTION: On-off means 36B-36D are closed, and an on-off means 36A is opened, and then a pressing part 43 is pressed down with a gun moving means 13. Then, a paint 45A at a lower part of a second piston 32 is compressed and filled in a first paint storage means 20 via a branch passage 17A as shown in a thick line, a color change valve mechanism 25, and a paint supply passage 38. Accordingly, the branch passage 17A is pressurized by a second paint storage means 30A, so that it is not necessary to pressurize the inside of a paint circulation path 15A. In addition, it is sufficient if only one system of the paint circulation path 15A is prepared. As a result, the electrostatic coating apparatus can be compactified and simplified, and thereby the cost of equipment can be lowered.

Description

  The present invention relates to an electrostatic coating apparatus provided with a color change valve mechanism.

  Car bodies represented by passenger cars are painted with paints of various colors. The vehicle body is automatically painted with a painting gun attached to the arm of the robot (see, for example, Patent Document 1 (FIG. 2)).

  As shown in FIG. 2 of Patent Document 1, the paint supply units (P1 to P3) (numbers in parentheses indicate the reference numerals described in Patent Document 1) provided on the wall of the coating chamber after the completion of painting. The paint is supplied from one of the following to the storage tank (22). Specifically, the first complementary connecting means (29a) is connected to one of the connecting means (28a to 28c) on the wall side. Then, the paint is supplied to the storage tank (22) with the pressure of the paint supply unit (P1, P2 or P3).

The pressure of the paint supply part (P1, P2 or P3) cannot be increased extremely. Therefore, the filling time becomes long. That is, when the pressure is increased, the pressure resistance performance of the paint supply unit (P1, P2 or P3) is increased, and high pressure means is required.
However, if the filling time is extended, the productivity is deteriorated, so a countermeasure is required.

Therefore, a high-speed filling technique is proposed (see, for example, Patent Document 2 (FIGS. 1 and 3)).
As shown in FIG. 1 of Patent Document 2, there is a booth side paint blending chamber (12) in the vicinity of the painting booth (21) (the numbers in parentheses indicate the symbols described in Patent Document 2. The same applies hereinafter). Be placed. And as FIG. 3 of patent document 2 shows, a coating material is supplied to each coating device (23) with a coating material pump (142). Since the pressure is increased by the paint pressure pump (142), high-speed filling is possible.
However, the paint pressure pump (142) and the paint circulation path (143) must be provided for each color. As a result, equipment costs increase.

  There is a demand for an electrostatic coating apparatus that can shorten the filling time and reduce the equipment cost even if the color change is performed.

Japanese Unexamined Patent Publication No. Sho 63-175562 JP 2000-70826 A

  This invention makes it a subject to provide the electrostatic coating apparatus which can shorten filling time and can reduce installation expense even if it implements color change.

  The invention according to claim 1 provides a plurality of paint circulation paths that are provided for each color and circulates the paint, branch paths that extend from these paint circulation paths, and colors that are selected by being connected to the tips of these branch paths. A color change valve mechanism for discharging the paint, a paint supply path extending from the color change valve mechanism for sending the selected color paint, and storing the selected color paint provided at the tip of the paint supply path A first paint storage means, a coating gun which receives the supply of the paint from the first paint storage means and injects the paint onto an object to be coated, and a gun which moves while supporting the coating gun and the first paint storage means In the electrostatic coating apparatus comprising the moving means, each of the branch paths is provided with a second paint storage means for storing the paint.

  In the invention according to claim 2, the second paint storage means includes a plurality of cylinders that store paint, a plurality of pistons that are respectively housed in the cylinders and push out the paint, an actuator that reciprocates each of these pistons, And a controller that controls the actuator so that one of the pistons moves forward.

  The invention according to claim 3 is characterized in that there is one actuator, and the output of this actuator is transmitted to one of the plurality of pistons by the driving force switching mechanism.

  In the invention according to claim 4, the second paint storage means sends a plurality of cylinders for storing the paint, a plurality of pistons respectively housed in the cylinders to push out the paint, and a driving fluid behind these pistons. A driving fluid supply source, a fluid supply path connecting the driving fluid supply source and each of the pistons, on / off means provided in each of the fluid supply paths, and a control unit that controls opening / closing of the on / off means. It is characterized by becoming.

  According to a fifth aspect of the present invention, the driving fluid supply source includes a cylinder that stores fluid, a piston that is housed in the cylinder and pushes out the fluid, and a pressing portion that is pressed by the gun moving means.

  In the invention according to claim 1, since the second paint storing means for storing the paint is provided in each of the branch paths, only one system of paint paint path needs to be prepared for each color. As a result, an increase in equipment costs can be suppressed.

In addition, by providing the second paint storage means for each color, it is possible to reduce the cleaning loss in the second paint storage means.
Also, if the second paint storage means is provided in the downstream paint supply path (the paint path connecting the color change valve mechanism and the first paint storage means provided in the painting robot), it is unavoidable. In particular, the paint pressure is lowered, and there is a concern that the filling of the paint into the second paint storage means may be hindered.
In this regard, in the present invention, since the second paint storage means is provided in the upstream branch passage having a higher pressure than the paint supply path, the high paint is used to smoothly fill the second paint storage means. Is called.

  In the invention according to claim 2, the second paint storage means includes a plurality of cylinders, a plurality of pistons, an actuator for reciprocating each of the pistons, and a control for controlling the actuator so that one of the plurality of pistons moves forward. It consists of parts. Since only the actuator of the color to be used is operated, the operation energy such as electric energy can be reduced.

  In the invention according to claim 3, there is one actuator. Compared to preparing actuators by the number of colors, if there is one actuator, the procurement cost of the actuator can be greatly reduced, and the equipment cost of the electrostatic coating apparatus can be further reduced.

  In the invention according to claim 4, the second paint storage means includes a plurality of cylinders, a plurality of pistons, a driving fluid supply source for sending a driving fluid behind these pistons, and the driving fluid supply source and the piston. Each of the fluid supply paths, on / off means provided in each of the fluid supply paths, and a control unit that controls opening / closing of the on / off means. One drive fluid supply source for driving the piston can be provided. That is, as compared with the case where the driving fluid supply source is provided for each color, if the number of driving fluid supply sources is one, for example, the procurement cost of the driving fluid supply source can be greatly reduced, and the equipment of the electrostatic coating apparatus can be reduced. Costs can be further reduced.

  In the invention which concerns on Claim 5, a drive fluid supply source has a press part pushed by a gun moving means. That is, the driving fluid supply source is driven by the gun moving means. Since it is not necessary to provide an actuator in the driving fluid supply source, the driving fluid supply source can be made inexpensive, and the equipment cost of the electrostatic coating apparatus can be further reduced.

It is a top view of the electrostatic coating apparatus which concerns on this invention. It is 2-2 arrow line view of FIG. It is an effect | action figure of the electrostatic coating apparatus shown in FIG. It is a figure which shows the example of a change of the electrostatic coating apparatus shown in FIG. It is a figure which shows the example of a change of the electrostatic coating apparatus shown in FIG. It is a figure which shows the example of a change of the electrostatic coating apparatus shown in FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. For convenience of explanation, claim 2 will be described in detail with reference to FIG. 5, claim 3 with reference to FIG. 6, claim 4 with reference to FIG. 4, and claim 5 with reference to FIGS.

  As shown in FIG. 1, the electrostatic coating apparatus 10 includes a conveyor 12 that conveys a vehicle body 11 that is an object to be coated, gun moving means 13 that are disposed on both sides of the conveyor 12, and the conveyor 12. From a plurality (four in this example) of paint circulation paths 15A to 15D (which are distinguished by subscripts because of different paint colors; the same applies hereinafter) disposed outside the gun moving means 13, and from the paint circulation paths 15A to 15D Branch paths 17 </ b> A to 17 </ b> D branched toward the gun moving means 13.

The gun moving means 13 is preferably a so-called painting robot (painting robot), but any type can be used as long as it is a means for moving the painting gun 18 three-dimensionally.
Further, the paint circulation paths 15A to 15D are pipe lines for circulating the paint in order to always flow. The properties of the paint can be maintained by flowing.

  As shown in FIG. 2, the gun moving unit 13 includes a coating gun 18 and a first paint storage unit 20. The first paint storage unit 20 includes, for example, a first cylinder 21, a first piston 22 housed in the first cylinder 21, and a first actuator 23 that reciprocates the first piston 22. The paint gun 18 is supplied with paint from the first paint storage means 20 and paints the vehicle body 11.

  A color change valve mechanism 25 is provided in the vicinity of the gun moving means 13, and second paint storage means 30A to 30D are respectively connected to branch paths 17A to 17D connecting the color change valve mechanism 25 and the paint circulation paths 15A to 15D. Established. The second paint storage means 30 </ b> A to 30 </ b> D includes a second cylinder 31, a second piston (free piston) 32 movably accommodated in the second cylinder 31, and a driving fluid behind the second piston 32. One driving fluid supply source 40 to be sent, a fluid supply passage 34 connecting this driving fluid supply source 40 and each of the second cylinders 31, and an on / off means (on / off valve) provided in each of these fluid supply passages 34 36A to 36D and a control unit 37 that controls to open one of these on / off means 36A to 36D and close the rest.

One drive fluid supply source 40 includes a third cylinder 41, a third piston 42 accommodated in the third cylinder 41, and a pressing portion 43 extending from the inside of the third piston 42 to the outside of the third cylinder 41. .
Next, the operation of such an electrostatic coating apparatus will be described.

  In FIG. 2, during the painting operation by the painting gun 18, a predetermined amount of paint is supplied from the paint circulation paths 15 </ b> A to 15 </ b> D to the second paint storage means 30 </ b> A to 30 </ b> D. By being supplied, the second piston 32 rises, and the paints 45 </ b> A to 45 </ b> D are stored in a space below the second piston 32. As the second piston 32 rises, the working fluid 46 is pushed down, the third piston 42 rises, and the pressing portion 43 projects greatly upward.

  Next, as shown in FIG. 3, the on / off means 36 </ b> B to 36 </ b> D are closed (black indicates that the valve is closed), the on / off means 36 </ b> A is opened, and the gun moving means 13 pushes down the pressing portion 43. Then, the third piston 42 of the second paint storage means 30 </ b> A is lowered, the working fluid 46 is pressurized, and the working fluid 46 pressurizes the space above the second piston 32. As a result, the paint 45A below the second piston 32 is compressed and filled into the first paint storage means 20 via the branch path 17A, the color change valve mechanism 25, and the paint supply path 38 indicated by a thick line. At this time, there is no fear that the paint 45A flows back to the paint circulation path 15A due to the check action of the check valve 47. The check valve 47 may be changed to an on / off valve.

By controlling the opening / closing means 36 </ b> A to 36 </ b> D by the control unit 37, one of the paints 45 </ b> A to 45 </ b> D of any color can be filled in the first paint storage means 20.
Since the branch path 17A is pressurized by the second paint storage means 30A, it is not necessary to pressurize the interior of the paint circulation path 15A beyond the pressure necessary for the flow of the paint. In addition, only one system of the paint circulation path 15A needs to be prepared. As a result, the electrostatic coating apparatus can be made compact and simple, and the equipment cost can be reduced.

In addition, as shown in FIG. 4 (the sign is diverted from FIG. 3), the pressing portion 43 related to the third piston 42 may be pushed and pulled by the actuator 48. By providing the actuator 48, the burden on the gun moving means 13 can be reduced.
On the other hand, if it is FIG. 3, the actuator 48 of FIG. 4 can be omitted, and installation cost can be reduced more.

Next, a modified example of FIG. 3 will be described.
As shown in FIG. 5, the second paint storage means 30 </ b> A to 30 </ b> D include a plurality of second cylinders 31 that store paint, a plurality of second pistons 32 that are respectively stored in the second cylinders 31 and push out the paint, The plurality of second actuators 49 that reciprocate each of the second pistons 32 and a control unit 37 that controls the second actuator 49 so that one of the plurality of second pistons moves forward.
The second actuator 49 includes, for example, an electric motor, and has a mechanism for converting the rotational movement of the electric motor into the axial movement, and moves the second piston 32 forward and backward.

  The control unit 37 puts the three second actuators 49 into a braking state, and advances the second piston 32 with one second actuator 49. Then, as a result, the paint 45A below the second piston 32 of the second paint storage means 30A is compressed, and is supplied to the first paint storage means 20 via the branch path 17A, the color change valve mechanism 25, and the paint supply path 38 indicated by a thick line. Filled.

Next, a modified example of FIG. 5 will be described.
As shown in FIG. 6, there is one actuator (rotary actuator) 51, and the output of this actuator 51 is transmitted to one of the plurality of pistons 32 by the driving force switching mechanism 60. For example, the driving force switching mechanism 60 includes a main shaft 61 rotated by the actuator 51, a driving side bevel gear 62 provided on the main shaft 61, a driven side bevel gear 63 rotated by the driving side bevel gear 62, and these driven bevel gears. A support shaft 64 extending from the support shaft 64, clutches 65 </ b> A to 65 </ b> D interposed between the support shafts 64, and a converter 66 connected to the support shaft 64. The converter 66 is a mechanism such as a ball screw mechanism that converts rotational motion into linear motion.

  When the main shaft 61 is rotated by the actuator (rotary actuator) 51, the support shaft 64 is rotated. In the control unit 37, the three clutches 65B to 65D are opened and one clutch 65A is connected. As a result, the paint 45A below the second piston 32 of the second paint storage means 30A is compressed and filled into the first paint storage means 20 via the branch path 17A, the color change valve mechanism 25, and the paint supply path 38 indicated by a thick line. The

  Compared to FIG. 5, FIG. 6 only requires one actuator (rotary actuator) 51, so the cost of the electrostatic coating apparatus can be reduced.

  In addition, although the electrostatic coating apparatus of this invention is suitable for the coating of a vehicle body, it may be applied to the coating of household appliances and general industrial products.

  The electrostatic coating apparatus of the present invention is suitable for painting a vehicle body that is frequently changed in color.

  DESCRIPTION OF SYMBOLS 10 ... Electrostatic coating apparatus, 11 ... To-be-coated object (vehicle body), 15A-15D ... Paint circulation path, 17A-17D ... Branch path, 20 ... First paint storage means, 25 ... Color change valve mechanism, 30A-30D ... Second paint storage means, 31... Cylinder (second cylinder) constituting second paint storage means, 32. Piston (second piston) constituting second paint storage means, 34... Fluid supply path, 36A to 36D. ON / OFF means (ON / OFF valve), 37 ... control unit, 38 ... paint supply path, 40 ... driving fluid supply source, 41 ... cylinder (third cylinder) constituting the driving fluid supply source, 42 ... driving fluid supply source Piston (third piston), 43 ... pressing portion, 45A to 45D ... paint, 49 ... actuator (second actuator) constituting second paint storage means, 51 ... one actuator, 60 ... cutting of driving force For example mechanism.

Claims (5)

A plurality of paint circulation paths provided for each color to circulate the paint, branch paths extending from these paint circulation paths, and a color change valve that discharges the selected color paint connected to the ends of these branch paths A mechanism, a paint supply path that extends from the color change valve mechanism and sends the selected color paint, a first paint storage means provided at the tip of the paint supply path for storing the selected color paint, Electrostatic coating comprising a coating gun for receiving the supply of the paint from the first paint storage means and spraying the paint onto the object to be coated, and a gun moving means for moving the paint gun and the first paint storage means while supporting them. In the device
An electrostatic coating apparatus, wherein each of the branch paths is provided with second paint storage means for storing paint.   The second paint storage means includes a plurality of cylinders that store the paint, a plurality of pistons that are respectively housed in the cylinders and push out the paint, an actuator that reciprocates each of the pistons, and one of the plurality of pistons. The electrostatic coating apparatus according to claim 1, further comprising a control unit that controls the actuator.   3. The electrostatic coating apparatus according to claim 2, wherein there is one actuator, and an output of the actuator is transmitted to one of the plurality of pistons by a driving force switching mechanism.   The second paint storage means includes a plurality of cylinders that store the paint, a plurality of pistons that are housed in the cylinders and push out the paint, and a driving fluid supply source that sends a driving fluid behind these pistons. A fluid supply path connecting the driving fluid supply source and each of the pistons; on / off means provided in each of the fluid supply paths; and a control unit that controls opening / closing of the on / off means. The electrostatic coating apparatus according to claim 1.   5. The electrostatic fluid according to claim 4, wherein the driving fluid supply source includes a cylinder that stores the fluid, a piston that is housed in the cylinder and pushes out the fluid, and a pressing portion that is pressed by the gun moving unit. Painting equipment.

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