JP2008246384A - Electrostatic coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic coating apparatus capable of preventing insulation failure more surely, reducing the loss of a coating material and being miniaturized. <P>SOLUTION: The electrostatic coating apparatus 10 includes an insulation mechanism 16 between a coating gun 12 and a color changing valve 14. The insulation mechanism 16 is provided with a first valve part 36 having a first path 92 communicating with the color changing valve 14 and including a first valve body 42 movable in the axial direction and a second valve part 38 having a second path 96 communicating with the coating gun 12 and including a second valve body 70 movable in the axial direction, wherein when the first valve body 42 and the second valve body 70 are abutted to each other, the first path 92 and the second path 96 communicate with each other and when the first valve body 42 and the second valve body 70 are separated from each other, the first path 42 is blocked from the second path 96 and an insulating path 124 through which an insulating fluid flows between tip faces 42a and 70a of the first valve body 42 and the second valve body 70 is formed. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electrostatic coating apparatus that performs electrostatic coating using a conductive paint.

  In general, there is known an electrostatic coating apparatus that performs coating by discharging a conductive paint supplied from a paint supply valve in a state where a high voltage is applied to a coating gun.

  In this type of electrostatic coating apparatus, an insulating mechanism is interposed between the paint supply valve and a cylinder that supplies the paint from the paint supply valve to the paint gun, and the paint supply valve and the cylinder are electrically connected. Is electrically insulated. This prevents voltage leakage from the cylinder or paint gun to the paint supply valve during painting, thereby realizing good electrostatic painting.

  In the patent document 1, the present applicant has proposed an electrostatic coating apparatus provided with a tube made of an insulating material as the insulating mechanism. In this case, at the time of painting, first, the paint from the paint supply valve is filled into the cylinder from the tube. Next, after flowing the cleaning liquid from the cleaning valve from one end side to the other end side of the tube, the inside of the tube is dried by flowing air to ensure insulation performance.

  Further, the present applicant has proposed an electrostatic coating apparatus having an insulating mechanism that mechanically (physically) separates the valve body part on the paint supply valve side and the valve body part on the cylinder side in Patent Document 2. ing. In this electrostatic coating apparatus, the paint supply path can be mechanically completely separated, and voltage leakage can be more reliably prevented.

JP 2000-354796 A Japanese Patent No. 3069278

  By the way, in this kind of electrostatic coating apparatus, further improvement of insulation performance for further improving the quality of electrostatic coating and further reduction of paint loss for environmental consideration and cost reduction are desired. . In addition, in such an electrostatic coating apparatus, in order to make the production line for reducing the installation space compact, it is required to ensure both insulation performance in the insulation mechanism and downsizing of the apparatus.

  The present invention has been made in connection with the above-described conventional technology, and provides an electrostatic coating apparatus that can prevent insulation failure more reliably, reduce paint loss, and achieve downsizing. The purpose is to do.

  An electrostatic coating apparatus according to the present invention includes a coating gun that discharges conductive paint, and a paint supply valve that supplies the paint gun with a paint, and an insulating mechanism is provided between the paint gun and the paint supply valve. An electrostatic coating apparatus provided, wherein the insulating mechanism includes a first valve portion having a first path communicating with the paint supply valve and having a first valve body movable in an axial direction, and the coating gun And a second valve portion having a second valve body that is movable in the axial direction and having a second path that communicates with the first valve body, the tip surfaces of the first valve body and the second valve body face each other and are in contact with each other. The first valve body and the second valve body are integrally moved in the axial direction by allowing the distal end surfaces to abut each other and being disposed in a space through which the insulating fluid can flow. When the first path and the second path are in communication with each other and the tip surfaces are separated from each other, With said first path and the second path is blocked, between each tip surface, wherein an insulating route said insulating fluid flows is formed.

  According to such a configuration, the path on the paint supply valve side and the path on the paint gun side can be physically separated by the insulating mechanism, and a high voltage is applied during electrostatic coating. The voltage leakage from the path to the path on the paint supply valve side can be prevented. Further, in the insulation mechanism, an insulating fluid having a sufficiently high insulation resistance is circulated through an insulation path formed between the first valve portion and the second valve portion separating the paint supply valve side and the paint gun side. Further, it is possible to more reliably insulate between the paint supply valve side and the paint gun side. In this case, the insulating distance is higher than that in the case where the insulating fluid is not circulated, for example, by circulating an insulating fluid having a higher insulation resistance than air in the insulating path, that is, compared to the case where air or the like is retained in the insulating path. The width of the insulating path can be further reduced. Therefore, the electrostatic coating apparatus can be downsized.

  The first valve portion includes a first valve body that is slidably mounted on the first valve body and is configured to be movable back and forth in the axial direction, and a taper provided on the first valve body. A tapered surface provided on the first valve body can be brought into close contact with the first valve body, and the second valve body slidably houses the second valve body and a front end surface of the first valve body is in contact with the second valve body. A second valve body that can be separated; and a tapered surface provided on the second valve body can be brought into close contact with a tapered portion provided on the second valve body, and the first path includes the first valve The second valve body opens to the outer peripheral surface of the first valve body on the upstream side of the tapered surface of the body, and the second path includes a hole portion of the second valve body that houses the second valve body and the second valve body. When the first valve body and the second valve body are in contact with each other, the second valve body is driven forward to cause the first valve body to move. By pressing and retreating, the respective tapered surfaces are separated from the respective tapered portions, the first path and the second path are communicated, and the first valve body and the second valve body are separated from each other. The first valve body and the second valve body are urged by an elastic member so that the tapered surfaces are in close contact with the tapered portions, and the first path and the second path are blocked. can do.

  In this case, when the first valve body and the second valve body are separated, the tapered surface is brought into close contact with the tapered portion by the urging force of the elastic member, so that the first path and the second path are reliably blocked. Therefore, paint leakage from the first path and the second path when separating the first valve body and the second valve body can be prevented, and paint loss can be reduced.

  According to the present invention, the path on the paint supply valve side and the path on the paint gun side are separated by the first valve portion and the second valve portion constituting the insulating mechanism, and the first valve portion and the first valve portion are separated from each other. An insulating fluid can be circulated through an insulating path formed between the two valve portions. Therefore, it is possible to reliably prevent a voltage leak from the coating gun side path to which a high voltage is applied during electrostatic coating to the paint supply valve side path. In addition, for example, when an insulating fluid having a higher insulation resistance than air is circulated through the insulating path, the insulating fluid is not circulated, that is, compared to a case where air or the like is retained in the insulating path. The width of the insulating path can be further reduced. For this reason, the electrostatic coating apparatus can be miniaturized.

  Further, the first valve body and the second valve body are provided on the first valve body and the second valve body, respectively, by urging the first valve body and the second valve body housed in the first valve body and the second valve body with an elastic member. The tapered surface is brought into close contact with the tapered portions provided in the first valve body and the second valve body, respectively, so that the first path and the second path can be reliably blocked. Therefore, paint leakage from the first path and the second path when separating the first valve body and the second valve body can be prevented, and paint loss can be reduced.

  Hereinafter, preferred embodiments of an electrostatic coating apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an explanatory diagram of a block circuit of an electrostatic coating apparatus 10 according to an embodiment of the present invention. The electrostatic coating apparatus 10 is an apparatus that is mounted on, for example, an industrial robot (not shown) and discharges a predetermined color paint from a coating gun 12 to perform electrostatic coating on the body of an automobile. As the paint, a water-based paint which is a conductive paint is used.

  The electrostatic coating apparatus 10 includes a color change valve (paint supply valve) 14 that supplies paint of a predetermined color to a paint gun 12 from a paint supply source (not shown) that supplies each color paint at a high pressure, and the color change valve. And an insulation mechanism (separation insulation mechanism) 16 provided in the middle of a path through which the paint is introduced from the paint gun 12 to the paint gun 12. A cylinder 18 capable of filling and extruding paint is interposed between the insulating mechanism 16 and the coating gun 12. The cylinder 18 is filled with, for example, one body of paint, and functions to supply and discharge the paint stably (constantly) to the paint gun 12.

  The color change valve 14 supplies a plurality of paint valves 20 corresponding to each color paint, a cleaning liquid valve (water valve) 22 that supplies water (W) that is a cleaning liquid for water-based paint, and air (A) for drying. A switching valve device connected to a drying valve (air valve) 26 is configured. The paint supply source is connected to each paint valve 20, and when the paint valve 20 corresponding to a predetermined color is opened, the paint of the corresponding paint supply source is passed through the insulating mechanism 16 from the first supply path 28. It is supplied to the cylinder 18.

  The insulation mechanism 16 is disposed between the color change valve 14 and the cylinder 18 and is provided to appropriately electrically insulate a path through which the paint is supplied from the color change valve 14 to the cylinder 18. That is, in the direction of supplying paint from the color change valve 14 to the cylinder 18, the first supply path 28 is connected to the upstream side of the insulating mechanism 16, and the second supply path 30 is connected to the downstream side. The second supply path 30 connects between the insulating mechanism 16 and the cylinder 18.

  FIG. 2 is a cross-sectional view along the axial direction of the insulating mechanism 16 in a state where the first supply path 28 and the second supply path 30 are communicated with each other, and shows a state where insulation is not ensured. FIG. 3 is a cross-sectional view along the axial direction of the insulating mechanism 16 in a state where the first supply path 28 and the second supply path 30 are cut off, and shows a state in which insulation is ensured.

  As shown in FIGS. 2 and 3, the insulating mechanism 16 includes a body portion (case) 32 having a substantially cylindrical shape and an inner wall surface 32 a formed in a bellows shape having a slightly large amplitude, and one end side of the body portion 32. (The arrow X1 side, the upstream side) and a connecting portion 34 having a substantially cylindrical shape whose inner wall surface is formed as a cylinder 34a. Further, the insulating mechanism 16 includes a first valve portion 36 that is inserted from the rear end opening side of the connecting portion 34 into the connecting portion 34 and the main body portion 32 so as to be movable back and forth (slidable) in the arrow X1 direction. And a second valve portion 38 that is connected to the other end side (arrow X2 side, downstream side) of the main body portion 32 and is disposed to face the first valve portion 36.

  In the case of this embodiment, the main body portion 32, the connecting portion 34, the first valve portion 36, the second valve portion 38, and lid members 48 and 76 described later are made of an insulating material, such as PTFE (tetrafluoroethylene resin) or It is formed of a synthetic resin mainly composed of POM (polyacetal resin).

  The main body 32 is provided with a supply port 33 for supplying an insulating liquid to an internal space 32b surrounded by the inner wall surface 32a and a discharge port 35 for discharging. In this case, an insulating liquid having an insulation resistance larger than that of air is suitable, and examples thereof include an inert fluorine-based insulating liquid and insulating oil.

  The first valve portion 36 has a substantially columnar shape as a whole, a first valve body 40 having a substantially cylindrical shape constituting an outer peripheral surface, and a first valve body 40, which is mounted on the first valve body 40 so as to be movable in the axial direction. And a valve body 42.

  A piston 44 that can be driven back and forth within the cylinder 34a of the connecting portion 34 is provided on the slightly rear end side (arrow X2 side) of the outer peripheral surface of the first valve body 40. On the rear end side (arrow X2 side) of the inner peripheral surface of the first valve body 40, a cylinder 40a having a diameter larger than that of other portions is formed. Inside the cylinder 40a, a slider 46 provided on the rear end side in the axial direction of the outer peripheral surface of the first valve body 42 is disposed so as to be able to advance and retreat. The opening on the rear end side of the cylinder 40a is formed by the first valve body 42. The ring-shaped lid member 48 inserted is closed.

  Furthermore, two pilot ports 50 and 52 communicate with the cylinder 34a at both ends of the piston 44 in the forward and backward direction, and joints 54 and 56 are connected to the pilot ports 50 and 52, respectively. The joints 54 and 56 are connected to paths 62 and 64 from pilot valves 58 and 60 connected to an air supply source (not shown) for supplying high-pressure air (see FIG. 1). Therefore, when the pilot valve 58 is opened under the control of the control means (not shown) and high-pressure pilot air is supplied from the joint 54 and the pilot port 50 into the cylinder 34a, the piston 44 is driven backward in the direction of the arrow X2. Is done. That is, the first valve portion 36 is driven backward in the arrow X2 direction (see FIG. 3). Similarly, when the pilot valve 60 is opened and high-pressure pilot air is supplied from the joint 56 and the pilot port 52 into the cylinder 34a, the piston 44 is driven forward in the direction of the arrow X1. That is, the first valve portion 36 is driven forward in the direction of the arrow X1 (see FIG. 2).

  The cylinder 40a is provided with a spring (elastic member) 66 that urges the slider 46 in the forward direction (arrow X1 direction). That is, normally, the first valve body 42 is urged in the direction of the arrow X1 by the spring 66 (see FIG. 3).

  On the other hand, the second valve portion 38 has a substantially frustoconical shape with a through hole 68a formed in the axial direction, and is fixed to the main body portion 32. The second valve portion 38 is axially disposed in the through hole 68a. And a second valve body 70 that is movably mounted in the interior.

  The through hole 68a of the second valve body 68 has a front end side (arrow X2 side) opened to the internal space 32b side, and a stepped cylinder 68b is formed on the rear end side (arrow X1 side). In the cylinder 68b, a piston 72 formed on the rear end side (arrow X1 side) of the outer peripheral surface of the second valve body 70 is disposed in a large diameter portion that is larger in diameter than other portions so as to be able to advance and retreat. .

  The rear end side (arrow X1 side) of the cylinder 68b (through hole 68a) is closed by a lid member 76 in which a pilot port 74 communicating with the cylinder 68b is formed. A joint 78 is connected to the pilot port 74, and a path 82 from a pilot valve 80 to which an air supply source (not shown) for supplying high-pressure air is connected is connected to the joint 78 (see FIG. 1). ). Accordingly, when the pilot valve 80 is opened and high-pressure pilot air is supplied from the joint 78 and the pilot port 74 into the cylinder 68b under the control of the control means (not shown), the piston 72 is driven forward in the direction of the arrow X2. Is done. That is, the second valve body 70 is driven forward in the direction of the arrow X2 (see FIG. 2).

  The cylinder 68b is provided with a spring 84 that urges the piston 72 in the backward direction (arrow X1 direction). That is, normally, the 2nd valve body 70 is urged | biased by the arrow X1 direction by the spring 84 (refer FIG. 3).

  In the insulating mechanism 16 configured as described above, the first supply path 28 is connected to the joint 86 coupled to the rear end side (arrow X2 side) of the first valve body 42 protruding from the lid member 48, and the second The second supply path 30 is connected to a joint 88 connected to a side surface (slope) of the valve body 68.

  FIG. 4 shows a partially sectional perspective view in which the distal ends of the first valve portion 36 and the second valve portion 38 are enlarged. 5A shows a partially omitted cross-sectional view in which the distal end side of the insulating mechanism 16 in a state where the first valve portion 36 and the second valve portion 38 are separated from each other, and FIG. 5B shows the first valve portion 36. FIG. 5C is a partially omitted cross-sectional view showing an enlarged front end side of the insulating mechanism 16 in a state of being in close contact with the second valve portion 38, and FIG. 5C is a view after the first valve portion 36 and the second valve portion 38 are in close contact with each other. FIG. 5 is a partially omitted cross-sectional view showing an enlarged front end side of the insulating mechanism 16 in a state where the second valve body 70 is driven forward.

  The first supply path 28 is connected to the joint 86 so as to communicate with a first path 92 formed in the first valve body 42 along the axial direction (see FIG. 2). As shown in FIG. 4, the first valve body 42 is provided with a tapered surface 42b continuously formed so as to increase in diameter from the peripheral edge portion of the front end surface 42a toward the rear end side (arrow X2 side). . The distal end side (arrow X1 side) of the first path 92 branches in a plurality of directions (two directions in this embodiment) on the slightly upstream side (arrow X2 side) from the tapered surface 42b (FIG. 5A, etc.). reference). One branch of the first path 92 is opened at the outer peripheral surface of the first valve body 42 at the opening 42c and the other at the opening 42d. An enlarged diameter portion 40b is provided around the inner peripheral surface of the first valve body 40 corresponding to the openings 42c and 42d, and the distal end side (arrow X1 side) of the enlarged diameter portion 40b is an opening of the distal end surface 40c. It continues to the taper part (valve seat) 40d reduced in diameter toward the part.

  On the other hand, the second supply path 30 is connected to the joint 88 so as to communicate with a path 94 formed in the second valve body 68. As shown in FIG. 4, the second valve body 70 is provided with a tapered surface 70b continuously formed so as to reduce in diameter from the peripheral edge portion of the front end surface 70a toward the rear end side (arrow X1 side). . The path 94 communicates with a second path 96 formed between the slightly enlarged diameter end side (arrow X2 side) of the through hole 68a and the outer periphery of the second valve body 70 (see FIG. 4 and FIG. 4). (Refer FIG. 5A etc.). The distal end side (arrow X2 side) of the through hole 68a constituting the second path 96 is continuous with a tapered portion 68d whose diameter is increased toward the opening portion of the distal end surface 68c.

  In the first valve portion 36, the tapered surface 42b of the first valve body 42 and the tapered portion 40d of the first valve body 40 are formed at the same angle, and the distal end surface 42a of the first valve body 42 and the first valve body 40 The opening formed in the front end surface 40c of 40 has substantially the same diameter. Therefore, as shown in FIG. 5A, when the taper surface 42b and the taper portion 40d contact each other, the first path 92 is blocked, and as shown in FIG. 5C, the taper surface 42b and the taper portion 40d are separated from each other. In this case, the first path 92 is opened. Similarly, in the second valve portion 38, the tapered surface 70b of the second valve body 70 and the tapered portion 68d of the second valve body 68 are formed at the same angle, and the distal end surface 70a of the second valve body 70 and the second valve body 70 are formed. The opening formed in the front end surface 68c of the main body 68 (the front end opening of the through hole 68a) has substantially the same diameter. Accordingly, as shown in FIG. 5A, when the tapered surface 70b and the tapered portion 68d contact each other, the second path 96 is blocked, and as shown in FIG. 5C, the tapered surface 70b and the tapered portion 68d are separated from each other. In this case, the second path 96 is opened.

  In this case, the front end surface 42a of the first valve body 42 and the front end surface 70a of the second valve body 70 are coaxially disposed as surfaces having the same diameter and being able to be in close contact with each other. That is, the opening formed in the distal end surface 40c and the opening formed in the distal end surface 68c have the same diameter, and the distal end surface 40c and the distal end surface 68c are configured to be in close contact with each other. Moreover, the tapered surfaces 42b and 70b and the tapered portions 40d and 68d are all formed in the same direction and at the same angle.

  Therefore, as shown in FIG. 5B, when the distal end surface 40 c of the first valve main body 40 comes into contact with the distal end surface 68 c of the second valve main body 68, the openings are in close contact with each other. In this state, when the high-pressure pilot air from the pilot valve 80 is supplied into the cylinder 68b and the piston 72 is pressed, the second valve body 70 resists the biasing force of the spring 84 and is on the tip side (in the direction of the arrow X2). Driven forward. That is, the tip surface 42 a is pressed in a state where the tip surface 70 a of the second valve body 70 is in close contact with the tip surface 42 a of the first valve body 42, and the first valve body 42 resists the urging force of the spring 66. Retreat in the X2 direction. As a result, the first path 92 and the second path 96 communicate with each other, that is, the first supply path 28 and the second supply path 30 communicate with each other.

  Furthermore, as shown in FIG. 1, the insulating mechanism 16 includes an insulating cleaning valve 102 connected via a path 100 to a supply port 33 that supplies an insulating liquid to the internal space 32 b. The insulating cleaning valve 102 includes an insulating liquid valve 104 that supplies the insulating liquid (I) to the internal space 32b, and a cleaning liquid valve (water valve) that supplies water (W) that is a cleaning liquid for cleaning the internal space 32b. ) 106 and a drying valve (air valve) 108 for supplying drying air (A). Waste liquid containing insulating liquid and the like from the internal space 32b is communicated from the discharge port 35 to a waste liquid storage tank (dump) 112 through a discharge path 110 provided with a discharge valve (dump valve) 113.

  The cylinder 18 includes a piston 116 that is driven back and forth by the motor 114. When the motor 114 is driven by a control means (not shown) and the piston 116 moves backward, the paint from the second supply path 30 is filled in the cylinder 18, and when the piston 116 moves forward, the coating gun 12 is passed through the third supply path 118. Is supplied with paint. The motor 114 may use a servo motor to easily and accurately control the forward / backward drive of the piston 116.

  The painting gun 12 includes a trigger valve 120 that turns on and off the discharge of the paint supplied from the third supply path 118 and a high voltage generator 122 that can generate a high voltage used during electrostatic painting. Yes.

  In each figure, reference numeral 13 is a seal member for maintaining airtightness at the connecting portion or sliding portion of each component, and for example, an O-ring or a piston ring is applied.

  Next, the operation of the electrostatic coating apparatus 10 basically configured as described above will be described.

  When filling the cylinder 18 with the paint, first, the first supply path 28 and the second supply path 30 are communicated with each other by bringing the first valve portion 36 and the second valve portion 38 constituting the insulating mechanism 16 into close contact with each other. That is, high-pressure pilot air from the pilot valve 60 is introduced into the cylinder 34a, and the piston 44 is pressed in the direction of the arrow X1. Then, the first valve portion 36 is driven forward in the direction of the arrow X1, and the distal end surface 40c of the first valve body 40 comes into contact with and closely contacts the distal end surface 68c of the second valve body 68 (see FIG. 5B).

  At this time, the taper surface 42 b of the first valve body 42 is brought into close contact with (seats) the taper portion 40 d of the first valve body 40 by the urging force of the spring 66 to block the first path 42. Similarly, the taper surface 70 b of the second valve body 70 is brought into close contact with (sitting on) the taper portion 68 d of the second valve body 68 by the urging force of the spring 84 to block the second path 96. Naturally, the front end surface 42a of the first valve body 42 and the front end surface 70a of the second valve body 70 are brought into contact with and in close contact with each other (see FIG. 5B).

  Next, high-pressure pilot air from the pilot valve 80 is introduced into the cylinder 68b, and the piston 72 is pressed in the direction of the arrow X2. Then, the second valve body 70 is driven forward in the distal direction (arrow X2 direction) against the biasing force of the spring 84, the distal end surface 70a presses the distal end surface 42a of the first valve body 42, and the first valve body 42 is retracted in the direction of the arrow X2 against the biasing force of the spring 66. Thus, the tapered surfaces 42b and 70b and the tapered portions 40d and 68d are opened, the first path 92 and the second path 96 are communicated, and the first supply path 28 and the second supply path 30 are communicated. .

  In this state, the cylinder 18 is filled with the paint from the desired paint valve 20 of the color change valve 14. That is, the paint from the paint valve 20 is sent from the first supply path 28 to the first path 92, and from the openings 42c and 42d of the first valve body 42 to the tapered surfaces 42b and 70b and the tapered parts 40d and 68d. After passing through the gap formed between them, it is sent from the path 94 to the second supply path 30 via the second path 96 (see FIG. 5C). In the cylinder 18, the piston 116 is retracted by the motor 114 in accordance with the filling of the paint, and the paint is filled.

  After the filling of the paint into the cylinder 18 is completed, the first valve portion 36 and the second valve portion 38 are separated (separated) to ensure insulation in the insulating mechanism 16. That is, first, the supply of pilot air from the pilot valve 80 is stopped. Then, the second valve body 70 is retracted to the rear end side (arrow X1 side) by the urging force of the spring 84, and at the same time, the first valve body 42 is advanced to the front end side (arrow X1 side) by the urging force of the spring 66. The Thereby, the taper surface 42b and the taper portion 40d, and the taper surface 70b and the taper portion 68d come into close contact with each other, and the first path 92 and the second path 96 are blocked, and the first supply path 28 and the second supply path 30 are closed. Are blocked (see FIG. 5B).

  Next, after stopping the supply of pilot air from the pilot valve 60, high-pressure pilot air from the pilot valve 58 is introduced into the cylinder 34a, and the piston 44 is pressed in the direction of the arrow X2. Then, the first valve portion 36 is driven backward in the direction of the arrow X2, and the distal end surface 40c of the first valve body 40 is separated from the distal end surface 68c of the second valve body 68 by a predetermined distance.

  At this time, as described above, the taper surface 42b comes into close contact with the taper portion 40d by the biasing force of the spring 66 to block the first path 92, and the taper surface 70b comes into close contact with the taper portion 68d by the biasing force of the spring 84. The second path 96 is blocked (see FIG. 5A). Accordingly, in the internal space 32b of the main body 32, the first path 92 and the second path 96 are completely closed, and the first valve section 36 is separated from the second valve section 38 when the first valve section 36 is separated. There is almost no paint leakage from the path 92 or the second path 96.

  In this state, by opening the insulating liquid valve 104 constituting the insulating cleaning valve 102, the insulating liquid is supplied from the path 100 into the internal space 32 b of the main body 32 through the supply port 33. The insulating liquid supplied into the internal space 32b flows to the discharge port 35 side (the lower portion of the internal space 32b) while flowing on the outer periphery of the first valve body 40, and the front end surfaces 40c, 42a of the first valve portion 36. And the insulating path 124 formed by separating the tip surfaces 68c and 70a of the second valve portion 38 from each other. Thus, when the insulating liquid flows into the insulating path 124, a small amount of paint leaks from the first path 92 and the second path 96 when the first valve portion 36 and the second valve portion 38 are separated. Even in such a case, the paint is washed with an insulating liquid. For this reason, when the 1st valve part 36 and the 2nd valve part 38 are closely_contact | adhered again, it can prevent effectively that the coating material which leaked and adhered hardens | cures and obstructs contact | adherence, and smooth contact and separation are possible. Become.

  Accordingly, when the insulating liquid is initially supplied, the discharge valve 113 is opened, so that the insulating liquid (waste liquid) after cleaning the leaked paint in the insulating path 124 passes from the discharge port 35 through the discharge path 110. And discharged to the waste liquid storage tank 112. After a predetermined time, the discharge valve 113 is closed, and the insulating liquid valve 104 is closed in a state in which the internal space 32b including the insulating path 124 is sufficiently filled with the insulating liquid. Thereby, the insulation between the 1st valve part 36 and the 2nd valve part 38, ie, between the 1st supply path 28 (1st path 92) and the 2nd supply path 30 (2nd path 96), is carried out. Secured.

  In order to discharge the paint from the paint gun 12, the trigger valve 120 is opened and the piston 116 is advanced at a predetermined speed (constant speed) by the motor 114, so that the paint filled in the cylinder 18 has a predetermined flow rate (constant). The flow rate is extruded to the third supply path 118 and the paint is discharged through the trigger valve 120.

  In this case, a high voltage is applied to the coating gun 12 by the high voltage generator 122, and a high voltage is applied to the coating gun 12, the cylinder 18, the second valve portion 38, and each path in the middle of them. However, since the second valve portion 38 is reliably insulated from the first valve portion 36, the discharge port 35, and the like, even if the paint is a conductive paint such as a water-based paint, the color change valve 14 In addition, voltage leakage to the waste liquid storage tank 112 does not occur, and good electrostatic coating is possible.

  When each path is washed when a different color paint is filled in the cylinder 18 after the painting with the predetermined paint is completed, first, as in the case of filling the cylinder 18 with the paint, the first valve portion. The first supply path 28 and the second supply path 30 are communicated by bringing 36 into close contact with the second valve portion 38 again. Next, the cleaning liquid (water) is supplied from the cleaning liquid valve 22 constituting the color change valve 14, and the cleaning waste liquid may be discharged from the trigger valve 120 while cleaning the route to the coating gun 12.

  As described above, when the first valve portion 36 is brought into close contact with the second valve portion 38 again, the discharge valve 113 is opened to discharge the insulating liquid in the internal space 32b, and from the cleaning liquid valve 106. The interior space 32b is washed with water, and then dried with air from the drying valve 108. As a result, the front end surfaces 40c and 42a of the first valve portion 36 and the front end surfaces 68c and 70a of the second valve portion 38 can be reliably washed and dried, and the insulating liquid infiltrates between the close contact surfaces at the time of recontact. Such a situation can be surely prevented. In the state where the first valve portion 36 and the second valve portion 38 are separated, the first path 92 and the second path 96 are reliably blocked as described above. For this reason, the close contact between the first valve portion 36 and the second valve portion 38 may be performed while the inner space 32b is filled with the insulating liquid.

  Further, while the first valve portion 36 and the second valve portion 38 are brought into close contact with each other and the coating material is charged into the cylinder 18, an insulating liquid is supplied into the internal space 32b, and the inner wall surface 32a and the first valve portion are supplied. A portion surrounded by the outer peripheral surface 36 can be filled with an insulating liquid. As a result, the first valve portion 36 and the second valve portion 38 are separated, and at the same time, the insulating liquid flows into the insulating path 124 and can immediately fill the insulating liquid into the internal space 32b. Further shortening is possible.

  As described above, according to the electrostatic coating apparatus 10 according to the present embodiment, the insulating mechanism 16 is provided between the first supply path 28 on the color change valve 14 side and the second supply path 30 on the cylinder 18 side. It can be mechanically (physically) separated and reliably insulated. Accordingly, voltage leaks from the second valve portion 38 and the cylinder 18 side portion of the insulating mechanism 16 to which a high voltage is applied during electrostatic coating to the first valve portion 36 and the color change valve 14 side and the waste liquid storage tank 112. There is nothing to do.

  Further, the insulating path 124 formed between the front end surfaces 40c and 42a of the first valve portion 36 and the front end surfaces 68c and 70a of the second valve portion 38 is filled with an insulating liquid having a sufficiently high insulation resistance. Thus, for example, the insulating performance can be further improved as compared with the case where the insulating path 124 is filled with air. Therefore, in the state where the first valve portion 36 and the second valve portion 38 are separated, the width W (see FIG. 5A) of the insulation path 124 which is an insulation distance can be further shortened, and the insulation mechanism 16 (electrostatic coating) The apparatus 10) can be reduced in size.

  Further, when the first valve portion 36 and the second valve portion 38 are separated, the taper surface 42b is brought into close contact with the taper portion 40d by the urging force of the spring 66 to block the first path 92 and the spring 84 is attached. The second path 96 can be blocked by bringing the tapered surface 70b into close contact with the tapered portion 68d by the force. For this reason, paint leakage from the first path 92 and the second path 96 hardly occurs at the time of separation, and even if leakage occurs, the paint loss is extremely small, so that paint loss can be greatly reduced. . In particular, in the case of the electrostatic coating apparatus 10 according to the present embodiment, when the same color paint is used continuously, it can be used with little paint loss.

  In the electrostatic coating apparatus 10, there is no portion that causes wear in the contact portion between the first valve portion 36 and the second valve portion 38, and wear due to continuous use is prevented, thereby preventing paint leakage. can do.

  As described above, the inner wall surface 32a of the main body 32 constituting the insulating mechanism 16 is formed in a bellows shape having a slightly large amplitude. Therefore, the voltage leak transmitted from the second valve body 70 to which the high voltage is applied to the surface of the inner wall surface 32a cannot be transmitted to the first valve body 42 unless a considerable distance is passed along the inner wall surface 32a ( (See arrow A in FIG. 3). That is, the insulating mechanism 16 can reliably prevent voltage leakage from the surface of the inner wall surface 32a.

  In the above-described embodiment, the first valve body 42 is pressed and retracted by the second valve body 70. Naturally, the second valve body 70 may be retracted by the first valve body 42. it can. In this case, the angle (inclination) direction of the tapered surfaces 42b and 70b and the tapered portions 40d and 68d, the arrangement of the springs 66 and 84, and the pilot air supply position may be appropriately changed.

  The front end side (downstream side) of the first path 92 formed in the first valve body 42 is assumed to open to the outer peripheral surface of the first valve body 42 through two openings 42c and 42d. The number of parts can be one or three or more. The first path 92 need not be branched when there is one opening, and may be branched according to the number when there are three or more openings.

  As described above, the present invention has been described with the embodiment. However, the present invention is not limited to this, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

It is block circuit explanatory drawing of the electrostatic coating apparatus which concerns on one Embodiment of this invention. It is sectional drawing which follows the axial direction of the insulation mechanism in the state which connected the 1st supply path and 2nd supply path of the electrostatic coating apparatus shown in FIG. It is sectional drawing in alignment with the axial direction of the insulation mechanism in the state which interrupted | blocked the 1st supply path and 2nd supply path of the electrostatic coating apparatus shown in FIG. The partial cross-sectional perspective view which expanded the front end side of the 1st valve part and 2nd valve part which are shown in FIG. 3 is shown. FIG. 5A is a partially omitted cross-sectional view in which the front end side of the insulating mechanism in a state where the first valve portion and the second valve portion are separated from each other, and FIG. 5B is a diagram illustrating the first valve portion as the second valve portion. FIG. 5C is a partially omitted cross-sectional view in which the front end side of the insulating mechanism in an intimate contact state is enlarged. FIG. 5C is a diagram in which the second valve body is driven forward after the first valve portion and the second valve portion are brought into close contact with each other. It is a partially-omission sectional view which expanded the front end side of the insulating mechanism in the made state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrostatic coating apparatus 12 ... Coating gun 14 ... Color change valve 16 ... Insulation mechanism 18, 34a, 40a, 68b ... Cylinder 28 ... 1st supply path 30 ... 2nd supply path 32 ... Main-body part 32b ... Internal space 36 ... 1st valve part 38 ... 2nd valve part 40 ... 1st valve main body 40c, 42a, 68c, 70a ... Tip surface 40d, 42b, 68d, 70b ... Tapered surface 42 ... 1st valve body 66, 84 ... Spring 68 ... 1st 2 valve body 70 ... 2nd valve body 92 ... 1st path | route 96 ... 2nd path | route 124 ... insulation path | route

Claims (2)

An electrostatic coating apparatus having a paint gun for discharging conductive paint, and a paint supply valve for supplying paint to the paint gun, and having an insulating mechanism between the paint gun and the paint supply valve,
The insulating mechanism includes a first valve portion having a first path communicating with the paint supply valve and having a first valve body movable in the axial direction;
A second valve portion having a second passage communicating with the coating gun and having a second valve body movable in the axial direction;
With
The tip surfaces of the first valve body and the second valve body face each other and can be contacted and separated, and are disposed in a space through which an insulating fluid can flow.
When the tip surfaces are brought into contact with each other and the first valve body and the second valve body are moved together in the axial direction, the first path and the second path communicate with each other,
When the tip surfaces are separated from each other, the first path and the second path are blocked, and an insulating path through which the insulating fluid flows is formed between the tip surfaces. Electrostatic coating equipment. The electrostatic coating apparatus according to claim 1,
The first valve portion includes a first valve body that is slidably mounted on the first valve body and is configured to be movable back and forth in the axial direction. A tapered portion provided on the first valve body is provided on the first valve body. , The tapered surface provided on the first valve body can be closely contacted,
The second valve portion includes a second valve body that slidably houses the second valve body and capable of contacting and separating a tip end surface of the first valve body, and is provided on the second valve body. A tapered surface provided on the second valve body can be brought into close contact with the tapered portion,
The first path opens to the outer peripheral surface of the first valve body on the upstream side of the tapered surface of the first valve body,
The second path is formed between a hole in the second valve body that houses the second valve body and an outer peripheral surface of the second valve body,
When the first valve body and the second valve body are in contact with each other, the second valve body is driven forward to press and retract the first valve body so that each tapered surface is The first path and the second path communicate with each other apart from the taper portion,
When the first valve body and the second valve body are separated from each other, the first valve body and the second valve body are urged by an elastic member, so that the respective tapered surfaces are each tapered portion. The electrostatic coating apparatus is characterized in that the first path and the second path are blocked in close contact with each other.

Images