JP6261081B2 - Electrostatic painting gun - Google Patents

Description

  The present invention relates to an electrostatic coating gun.

  Patent Document 1 discloses an electrostatic coating gun for performing coating by applying a high voltage to a metallic paint. This electrostatic coating gun has a gun main body provided with a nozzle at a distal end portion, and a grip that extends from the base end portion of the gun main body and is grounded. A high voltage generator having electrodes arranged in the vicinity of the nozzle is accommodated in the gun body. A paint supply path for supplying metallic paint to the nozzle is provided between the base end of the grip and the tip of the gun body. The metallic paint supplied through the paint supply path is applied with a high voltage by an electrode at the tip of the supply gun body, and is ejected from the nozzle in an atomized state.

  In this electrostatic coating gun, there is a concern that the voltage applied to the metallic paint leaks to the grip through the metallic paint in the paint supply path. Therefore, as a countermeasure against leakage, a part of the paint supply path is a coiled flow path, so that a leak path from the downstream end (tip end of the gun body) to the upstream end (base end of the grip) of the paint supply path The insulation is improved by securing a long time.

JP 2000-246168 A

  When the electrostatic coating gun is a hand gun, weight reduction is required to reduce the burden on the operator. Therefore, it is preferable to use a flexible synthetic resin tube as the coiled channel. However, since a flexible tube has low pressure resistance, it cannot be applied when supplying metallic paint at a high pressure.

  The present invention has been completed based on the above-described circumstances, and in an electrostatic coating gun that ensures insulation by a coiled flow path made of flexible synthetic resin, it is possible to supply paint at high pressure. It aims to be realized.

The electrostatic coating gun of the present invention is
The gun body,
A nozzle provided at the tip of the gun body, for discharging conductive paint;
A ground member connected to the base end of the gun body;
An upstream end is attached to the ground member, a downstream end is attached to the tip of the gun body, and a paint supply path for supplying conductive paint to the tip of the gun body,
A high voltage generator provided in the gun body, for applying a high voltage to the conductive paint at the tip of the gun body;
A coil-shaped flow path comprising a tube made of a synthetic resin having flexibility, constituting the paint supply path;
It is made of an insulating material, and includes a reinforcing member that restricts the coiled flow path from being expanded and deformed .
The reinforcing member is
An insulating case surrounding the coiled flow path;
It is characterized in that it is made of an insulating incompressible material and is provided with a filler that abuts on the outer periphery of the coiled flow path in a state of being filled and solidified in the case .

Since the coil-shaped flow path made of synthetic resin is restricted in diameter expansion deformation by the reinforcing member, it is possible to supply the conductive paint at a high pressure. Further, it is possible to reliably prevent the coil-shaped flow path from being enlarged and deformed. In the present invention, the conductive paint is defined as a paint that includes a material that causes electrical leakage and normally requires countermeasures against leakage at the painting site.

Partially cutaway side view of the electrostatic coating gun of Example 1 Sectional view of the paint supply cartridge (paint supply path) Partial cutaway side view of tube Partial enlarged sectional view of paint supply cartridge (paint supply path)

(1) In the electrostatic coating gun of the present invention, the inner peripheral surface of the case may be in contact with a part of the outer peripheral surface of the coiled channel. According to this configuration, the deformation of the coil-shaped flow path so as to increase the outer diameter of the coil can be restricted by the case, so that the filling amount of the filler can be suppressed accordingly.

(2) The electrostatic coating gun according to the present invention may have a configuration in which the coiled flow path is tightly wound in (1) . According to this configuration, the diameter of the coiled flow path can be restricted by the contact between the coiled flow paths, so that the filling amount of the filler can be reduced accordingly.

(3) The electrostatic coating gun according to the present invention is the electrostatic coating gun according to (1) or (2), wherein the end of the tube is connected to an end of the coiled flow path and extends substantially parallel to the coil axis. And a connection hole to be connected by inserting the connection end portion is provided at an end portion of the case, and the coiled flow path is formed by the molded resin filler. The movement may be restricted with respect to the case. According to this configuration, it is possible to prevent the connection end from coming out of the connection hole.

<Example 1>
Embodiment 1 of the present invention will be described below with reference to FIGS. The electrostatic coating gun of the first embodiment is called a hand gun that is held and used by an operator, and is applied by supplying a conductive paint (not shown) at a high pressure (about 0.6 MPa to 21 MPa). It is used to do.

<Overall configuration of electrostatic coating gun>
The electrostatic coating gun is provided at a gun body 10 to which a trigger 11 is attached, a distal end portion (left end portion in FIG. 1) of the gun body 10, a nozzle 12 that discharges conductive paint, and a proximal end of the gun body 10. A grip 13 (grounding member described in claims) provided to be connected to a part and grounded, and a high voltage that is provided in the gun body 10 and applies a high voltage to the conductive paint at the tip of the gun body 10 A generator 14 and a paint supply cartridge 20 (a paint supply path described in claims) for supplying conductive paint to the tip of the gun body 10 are provided. When the trigger 11 is operated, the on-off valve 16 of the gun body 10 is opened, and the conductive paint supplied to the tip of the gun body 10 passes through the on-off valve 16 and the high voltage is generated by the electrode 15 of the high voltage generator 14. In a state where the pressure is applied, the liquid is discharged from the nozzle 12 in an atomized state.

  The conductive paint is a paint that contains a material that causes electrical leakage and usually requires countermeasures against leakage at the painting site. Specifically, it is a metallic paint containing metallic flakes (conductive pigments) in the main agent. The downstream end (upper end portion in FIG. 1) of the coating material supply cartridge 20 that is a flow path of the conductive coating material is a position close to the distal end portion of the gun body 10 (that is, the nozzle 12 and the electrode 15 of the high voltage generator 14; It is attached to a charged portion where a high voltage is applied to the conductive paint. On the other hand, the upstream end (lower end in FIG. 1) of the paint supply cartridge 20 is attached to the base end (lower end in FIG. 1) of the grip 13. Since the grip 13 is grounded, the entire grip 13 including the base end portion is a ground point.

  For this reason, there is a concern that the voltage applied to the conductive paint at the tip of the gun body 10 is transmitted to the metallic flakes in the paint supply cartridge 20 and leaks to the grip 13. Thus, the coating material supply cartridge 20 arranged between the charging part and the earth point becomes a leak path. As a countermeasure, a coil-shaped flow path 22 is provided in the paint supply cartridge 20 to lengthen the leak path from the charged portion to the ground point, thereby ensuring a long insulation distance.

<Paint supply cartridge 20>
As shown in FIG. 2, the coating material supply cartridge 20 includes a tube 21 constituting a coiled flow path 22, a reinforcing member 26 for preventing deformation of the coiled flow path 22, and a connecting end on the distal end side of the tube 21. The first joint 33A to which the portion 25A is connected and the second joint 33B to which the connection end 25B on the proximal end side of the tube 21 is connected are configured.

<Tube 21>
The tube 21 is made of a synthetic resin having electrical insulation and has flexibility. The tube 21 has a circular cross section, is formed in a straight line, and is then heat-treated in a state of being wound around a cylindrical forming jig (not shown). As a result, a coiled flow path 22 is formed in which most of the region excluding both ends of the tube 21 forms a close spiral. The coil shaft 24 of the coiled flow path 22 is linear, and the coil diameter of the coiled flow path 22 is a constant dimension over the entire length. The coil-shaped flow path 22 is configured by arranging a plurality of spiral winding portions 23 that go around the coil shaft 24 along the coil shaft 24, but the outer circumferences of the adjacent spiral winding portions 23 are They are in contact with each other in the direction parallel to the coil shaft 24.

  Both end portions of the tube 21 are a pair of connection end portions 25 </ b> A and 25 </ b> B extending from both end portions of the coil-shaped flow path 22 in parallel with the coil shaft 24 and substantially concentrically with the coil shaft 24. Since the tube 21 is a single component, the coiled flow path 22 and the pair of connection end portions 25A and 25B are integrated. Compared to the overall length of the molded tube 21 in which the coil-shaped flow path 22 is formed (distance from the extended end of one connecting end 25A to the extended end of the other connecting end 25B), the coiled flow It is shorter than the full length dimension of the linear tube 21 before forming the path 22. Therefore, compared with the full length dimension of the tube 21 in which the coiled flow path 22 is formed, the flow path (that is, the insulation distance) of the conductive paint in the tube 21 is ensured long.

  Since the tube 21 in which the coil-shaped flow path 22 is formed is made of a synthetic resin having flexibility, when the coating material is pumped at a high pressure, the tube 21 is deformed to expand and a predetermined pressure cannot be obtained. Therefore, the use of the tube 21 alone is limited to the case where the paint is supplied at a low pressure of about 0.6 MPa or less. Thus, in the first embodiment, the diameter of the tube 21 is prevented from being deformed by providing the reinforcing member 26 in order to enable high pressure pumping of the conductive paint.

<Reinforcing member 26>
The reinforcing member 26 includes a case 27 made of an electrically insulating material and a filler 39 made of an electrically insulating material. The case 27 has a cylindrical shape, the distal end side region of the case 27 is a small diameter cylindrical portion 28, and the proximal end side region of the case 27 is a large diameter cylindrical portion 29 having a larger inner diameter than the small diameter cylindrical portion 28. ing. A stopper 30 that protrudes inward is formed on the inner periphery of the tip of the small-diameter cylindrical portion 28. A first through hole 31 </ b> A penetrating from the inner peripheral surface of the small diameter cylindrical portion 28 to the outer peripheral surface is formed at the base end portion (portion close to the large diameter cylindrical portion 29) of the small diameter cylindrical portion 28. An internal thread portion 32 is formed on the inner periphery of the base end portion of the large diameter cylindrical portion 29. The large diameter cylindrical portion 29 is formed with a second through hole 31 </ b> B penetrating from the inner peripheral surface of the large diameter cylindrical portion 29 to the outer peripheral surface. A tube 21 is accommodated in the case 27.

<First joint 33A>
The first joint 33A is attached to the distal end portion (downstream end portion) of the case 27 (small diameter cylindrical portion 28) so as to close the opening in a liquid-tight manner. The first joint 33A has a cylindrical shape and is made of an electrically insulating material. The first joint 33A includes a first joint 34A, a first lock ring 36A, and a first lock nut 38A. The tube 21 is connected to the first joint 33A outside the case 27 as follows.

  A connection end portion 25A on the distal end side of the tube 21 is inserted into the first connection hole 35A on the inner periphery on the proximal end side of the first joint 34A. The first lock ring 36A is externally fitted to the connection end 25A, and the first tapered surface 37A on the outer periphery of the distal end of the first lock ring 36A faces the inner peripheral edge of the base end of the first joint 34A. The first lock nut 38A is screwed into the outer periphery of the proximal end portion of the first joint 34A, and presses the first tapered surface 37A of the first lock ring 36A against the inner peripheral edge of the proximal end portion of the first joint 34A. The pressed first taper surface 37A causes the first lock ring 36A to be reduced in diameter due to its inclination, so that the first lock ring 36A bites into the outer periphery of the connection end 25A. Thereby, the connection end 25A on the distal end side of the tube 21 is connected to the first joint 33A.

<Second joint 33B>
The second joint 33B is attached to the base end portion (upstream end portion) of the case 27 (large diameter cylindrical portion 29) so as to close the opening in a liquid-tight manner. The second joint 33B has a cylindrical shape and is made of an electrically insulating material. The second joint 33B includes a second joint 34B, a second lock ring 36B, and a second lock nut 38B. The tube 21 is connected to the second joint 33B outside the case 27 as follows.

  A connection end 25B on the proximal end side of the tube 21 is inserted into the second connection hole 35B on the inner periphery on the distal end side of the second joint 34B. The second lock ring 36B is externally fitted to the connection end portion 25B, and the second tapered surface 38B on the outer periphery of the base end portion of the second lock ring 36B faces the inner peripheral edge of the distal end portion of the second joint 34B. The second lock nut 38B is screwed into the outer periphery of the end portion on the front end side of the second joint 34B, and presses the second tapered surface 38B of the second lock ring 36B against the inner periphery of the front end portion of the second joint 34B. The pressed second tapered surface 38B causes the second lock ring 36B to be reduced in diameter due to its inclination, so that the second lock ring 36B bites into the outer periphery of the connection end 25B. Thereby, the connection end 25B on the proximal end side of the tube 21 is connected to the second joint 33B.

  The first joint 33A, the second joint 33B, and the tube 21 connected as described above are inserted into the case 27 from the opening on the proximal end side of the large-diameter cylindrical portion 29 with the first joint 34A facing first. Is done. Then, the second joint 34 </ b> B is screwed into the female screw portion 32 on the inner periphery of the base end portion of the case 27. Then, the distal end of the first joint 34A passes through the opening on the distal end side of the case 27, and the stepped portion on the outer periphery of the first joint 34A comes into contact with the stopper 30, whereby the distal end side of the first joint 33A and the tube 21 is obtained. The connecting end portion 25 </ b> A is positioned with respect to the case 27. Thus, the first joint 33A, the tube 21, and the second joint 33B are fixed to the case 27.

  In a state where the tube 21 is accommodated in the case 27, the spiral winding portions 23 of the coiled flow path 22 abut against each other in the direction of the coil axis 24, and the outermost peripheral portion of the coiled flow path 22 is the case 27 (large It contacts the inner periphery of the diameter tube portion 29). After attaching the tube 21, the first joint 33 </ b> A, and the second joint 33 </ b> B to the case 27, the case 27 is filled with a filler 39. The filler 39 is made of a thermosetting resin material. The filling material 39 is injected into the case 27 from one of the first through holes 31A and the second through hole 31B into the case 27, and while being injected, the filler 39 is supplied from the other through holes 31A and 31B to the case. The air in 27 is discharged. When all the gaps in the case 27 are filled with the filler 39, the injection of the filler 39 is finished, and the filler 39 is solidified (cured) by heat treatment. That is, in the case 27, the tube 21 and the filler 39 are integrated by a resin mold. When the filler 39 is solidified, the manufacture of the coating material supply cartridge 20 provided with the coiled flow path 22 is completed.

  As shown in FIG. 4, in the case 27, in the outer periphery of the tube 21, the region that is in contact with the inner periphery of the case 27 and the region in which the spiral winding portions 23 are in contact with each other and the connection holes 35 </ b> A and 35 </ b> B are inserted. The solidified filler 39 is in contact with the area excluding the area. Therefore, even when a high pressure is applied to the inner periphery of the tube 21 when the high-pressure conductive paint is caused to flow in the tube 21, the presence of the solid filler 39 causes the tube 21 to Expanding deformation is prevented. Further, regarding the region of the outer periphery of the coil-shaped flow path 22 that is in contact with the inner periphery of the case 27, the diameter expansion deformation is prevented by the presence of the case 27 having high rigidity. Furthermore, regarding the region where the spirally wound portions 23 are in contact with each other, the same pressure is applied to the inner circumference of both, and the canceling state occurs, so that the diameter expansion deformation is prevented.

  As shown in FIG. 1, the coating material supply cartridge 20 screws the tip of the first joint 34 </ b> A into the female screw hole 17 provided on the lower surface of the tip of the gun body 10, and the second joint 34 </ b> B via the bracket / joint joint 18. By fixing to the base end portion of the grip 13, the gun body 10 and the grip 13 are attached. The paint supply cartridge 20 can be removed from the gun body 10 and the grip 13 by the reverse procedure. Accordingly, it is possible to easily perform maintenance for cleaning the inside of the tube 21 and work for exchanging the inside of the tube 21 due to clogging.

<Operation and Effect of Example 1>
The electrostatic coating gun of the first embodiment is provided with a gun body 10, a nozzle 12 that discharges conductive paint, and a grip 13 that is connected to the base end of the gun body 10 and is grounded. The upstream end is attached to the grip 13, the downstream end is attached to the tip of the gun body 10, and the paint supply cartridge 20 that supplies conductive paint to the tip of the gun body 10 is provided in the gun body 10. A coil-shaped flow path 22 comprising a high-voltage generator 14 for applying a high voltage to the conductive paint at the tip of the gun body 10 and a paint supply cartridge 20 and comprising a flexible synthetic resin tube 21. And a reinforcing member 26 that is made of an insulating material and restricts the diameter-shaped deformation of the coiled flow path 22. In this electrostatic coating gun, since the coil-shaped flow path 22 made of synthetic resin is restricted from expanding and deforming by the reinforcing member 26, the conductive paint can be supplied at a high pressure.

  The reinforcing member 26 includes an insulating case 27 that surrounds the coiled flow path 22, and an insulating filler that is filled in the case 27 and made of an incompressible material that contacts the outer periphery of the coiled flow path 22. 39. According to this configuration, it is possible to reliably prevent the diameter-enlargement deformation of the coiled flow path 22. Further, since the filler 39 is molded and solidified, the conductive paint can be pumped at a high pressure even if the tube 21 is thin.

  Further, the inner peripheral surface of the case 27 is in contact with a part of the outer peripheral surface of the coiled flow path 22. According to this configuration, deformation of the coil-shaped flow path 22 so as to increase the outer diameter of the coil can be restricted by the case 27, so that the filling amount of the filler 39 can be suppressed accordingly. Moreover, the coil-shaped flow path 22 is in a form of tightly wound. According to this configuration, the diameter of the coil-shaped flow path 22 can be restricted by the contact between the coil-shaped flow paths 22 so that the diameter of the coil-shaped flow path 22 is increased in the direction of the coil axis 24. Can do.

  In the electrostatic coating gun according to the first embodiment, both end portions of the tube 21 are connection end portions 25 </ b> A and 25 </ b> B extending from the end portion of the coil-shaped flow path 22 substantially in parallel with the coil shaft 24. The joints 33A and 33B provided at the ends of the case 27 are provided with connection holes 35A and 35B to be connected by inserting the connection ends 25A and 25B. The movement of the coil-shaped flow path 22 in the direction along the coil axis 24 with respect to the case 27 (that is, the insertion / removal direction with respect to the connection holes 35A and 35B) is restricted by the molded resin filler 39. Yes. According to this configuration, the connection end portions 25A and 25B can be prevented from coming out of the connection holes 35A and 35B.

<Other embodiments>
The present invention is not limited to the first embodiment described with reference to the above description and drawings. For example, the following first embodiment is also included in the technical scope of the present invention.
(1) In the first embodiment, the upstream end of the paint supply path is attached to the base end of the grip (grounding member), but the upstream end of the paint supply path is the tip of the grip (the end close to the gun body). You may attach to.
(2) In the first embodiment, the inner peripheral surface of the case is in contact with a part of the outer peripheral surface of the coiled flow path, but the inner peripheral surface of the case is not in contact with the outer peripheral surface of the coiled flow path. It is good also as a form.
(3) In the first embodiment, the coiled flow path is tightly wound, but the coiled flow paths may be in a non-contact form in the axial direction.
(4) In the first embodiment, the filler is in contact with both the coiled flow path and the connection end, but the filler is in contact with only the coiled flow path and is in contact with the connection end. It is good also as a form which does not.
(5) In the first embodiment, the connection end is connected to the end of the coiled flow path. However, the connection end may not extend from the end of the coiled flow path.
(6) In the first embodiment, the cross-sectional shape of the tube constituting the coiled flow path is circular, but the cross-sectional shape of the tube may be elliptical or oval.
(7) In Example 1 described above, a part of the outer periphery of the coiled channel is in contact with the inner periphery of the case, but a part of the outer periphery of the coiled channel is a slight gap with respect to the inner periphery of the case. May be in a non-contact state facing each other.
(8) In Example 1 described above, the conductive paint is a metallic paint containing metallic flakes (conductive pigment), and the metallic flakes are the main cause of leakage. The present invention can also be applied to a case where the conductive paint is a paint in which a solvent having a small electric resistance is a main factor of leakage.
(9) In the first embodiment, the case where the electrostatic coating gun is a hand gun that is held and used by an operator has been described. However, in the present invention, the electrostatic coating gun is an automatic gun attached to a robot. It can also be applied to.
<Reference example>
(1) In Example 1 described above, the filler is a solid (resin mold), but a mode in which the filler is an incompressible fluid (a liquid such as oil or a gel agent) is also conceivable.
(2) In the first embodiment, the reinforcing member is configured by the case and the filler. However, the case is not provided, and the reinforcing member is only a solid member made of resin that is integrated with the coiled flow path by molding. The form which comprises is also considered.

10 ... Gun body 12 ... Nozzle 13 ... Grip (grounding member)
14 ... High voltage generator 20 ... Paint supply cartridge (Paint supply path)
DESCRIPTION OF SYMBOLS 21 ... Tube 22 ... Coil-shaped flow path 24 ... Coil shaft 25A, 25B ... Connection end part 26 ... Reinforcement member 27 ... Case 35A ... 1st connection hole 35B ... 2nd connection hole 39 ... Filler

Claims (4)

The gun body,
A nozzle provided at the tip of the gun body, for discharging conductive paint;
A ground member connected to the base end of the gun body;
An upstream end is attached to the ground member, a downstream end is attached to the tip of the gun body, and a paint supply path for supplying conductive paint to the tip of the gun body,
A high voltage generator provided in the gun body, for applying a high voltage to the conductive paint at the tip of the gun body;
A coil-shaped flow path comprising a tube made of a synthetic resin having flexibility, constituting the paint supply path;
It is made of an insulating material, and includes a reinforcing member that restricts the coiled flow path from being expanded and deformed .
The reinforcing member is
An insulating case surrounding the coiled flow path;
An electrostatic coating gun comprising an insulating incompressible material and a filler that contacts the outer periphery of the coiled flow path in a state of being filled and solidified in the case . The electrostatic coating gun according to claim 1, wherein an inner peripheral surface of the case is in contact with a part of an outer peripheral surface of the coiled flow path . The electrostatic coating gun according to claim 1, wherein the coiled flow path is tightly wound . The end portion of the tube is a connection end portion extending from the end portion of the coiled flow path substantially parallel to the coil axis,
The end of the case is provided with a connection hole to be connected by inserting the connection end,
The electrostatic movement according to any one of claims 1 to 3, wherein the coil-shaped flow path is restricted with respect to the case by the molded resin filler. Paint gun.

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