JP2006102692A - Coating gun - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance maintenance property of an opening/closing valve part and to realize enhancement of workability of coating work. <P>SOLUTION: Five unit attachment parts 50 are provided on a manifold 12 at the tip side of a gun body 11. A valve unit 37 unitized with the opening/closing valve 36 for delivering the liquid (coating and washing liquid) flowing-in from a flowing-in port 58 from a flowing-out port 59 and an air cylinder 57 for driving it, is detachably mounted to the respective unit attachment parts 50. A liquid feeding pipe 45 connected to the flowing-in port 58 and a liquid feeding passage 48 are provided on the gun body 11. Further, a liquid returning passage and a liquid returning pipe for returning and circulating the coating from a return port 70 provided on the valve unit 37 are provided. When the opening/closing valve 36 is released by the air cylinder 57, the coating is delivered from the flowing-out port 59, passes through the liquid delivery passages 55, 27 in the order, arrives at a coating delivery passage 24a of the delivery nozzle 24 and is blown to an article to be coated from the delivery nozzle 24 in the state that it is charged by a pin electrode 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention comprises a gun body having a liquid passage for guiding a liquid such as paint pumped from a liquid supply source to a discharge nozzle, and an opening / closing valve in the middle of the liquid passage. The present invention relates to a coating gun that controls the discharge of liquid from a discharge nozzle.

  2. Description of the Related Art Conventionally, painting apparatuses that automatically perform painting operations using a painting gun have been provided with a color change valve that can supply a plurality of types of paint and cleaning liquid to the painting gun (for example, Patent Document 1). reference). A schematic configuration of this type of coating apparatus is shown in FIG. That is, the color change valve 3 is connected to the coating gun 1 via the paint supply pipe 2. The color change valve (manifold) 3 includes a plurality (six) of on-off valves 4 having a common outlet, and a paint supply source 5 is used for pressure feeding on the inlet side of each on-off valve 4. These are connected via a pump 6 (only one is shown). Further, a supply source 7 of a cleaning liquid (for example, thinner) is connected to one on-off valve 4 via a pump 8 for pressure feeding.

  Thus, by controlling each on-off valve 4 of the color change valve 3, it is possible to selectively supply a plurality of types of paint from the paint supply pipe 2 to the coating gun 1, and automatically perform coating. The type of paint used can be changed (so-called color change). Further, the interior of the color change valve 3, the paint supply pipe 2, and the coating gun 1 can be automatically cleaned by supplying a cleaning liquid when the color is changed or at the end of the painting operation. The on-off valve 4 is driven by an air cylinder (not shown), for example.

Although not shown, a painting robot in which a painting gun is attached to the tip of the robot arm and the above-described color change valve is incorporated in the arm is also conceivable (see, for example, Patent Document 2).
JP-A-6-126223 JP-A-9-308848

  By the way, in the coating apparatus as described above, in the on-off valve 4 of the color change valve 3 at the time of painting work, there may occur a defect or a failure such as dust or paint clumps clogging the seal portion. When trouble occurs, it is necessary to take measures such as removing the on-off valve 4 and replacing it. However, in the above-described conventional configuration, when such trouble occurs, it is necessary to disassemble and remove the on-off valve 4 and the air cylinder of the color change valve 3 individually, so there is a drawback that it takes time for maintenance, and the line is lengthened. I had to stop for hours.

  In the above-described conventional coating apparatus, the length of the paint path from the on-off valve 4 (color change valve 3) to the tip of the coating gun 1 is relatively long. As a result, there is a problem that the amount of paint to be discarded and the amount of cleaning liquid to be used increase.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a painting gun capable of improving the maintainability of the on-off valve portion and thus improving the workability of the painting work. .

  In order to achieve the above object, the painting gun of the present invention is provided with a liquid passage for guiding a liquid such as paint pressure-fed from a liquid supply source to a discharge nozzle in the gun body, and is opened and closed in the middle of the liquid passage. The valve is configured to control the discharge of the liquid from the discharge nozzle by opening and closing the opening and closing valve, and the opening and closing valve and an air cylinder that drives the opening and closing valve are incorporated in the body. And a unit mounting portion provided on the gun body, wherein the gun body includes a valve unit having an inflow port through which the liquid flows in from the paint passage and an outflow port for flowing out the liquid that has passed through the on-off valve to the discharge nozzle side. It is characterized in that it is configured so as to be detachably attached to the head (invention of claim 1).

  According to the coating gun of the present invention, the open / close valve for controlling the discharge of the liquid from the discharge nozzle and the air cylinder for driving the open / close valve are provided in the gun body, and the open / close valve and the air cylinder are provided in the valve unit. Are unitized and can be detachably attached to the unit mounting portion. Accordingly, when trouble such as a defective opening / closing valve occurs, maintenance can be easily performed by removing the valve unit from the unit mounting portion and replacing it. In addition, by providing a valve unit (open / close valve) in the gun body, compared to the case where an open / close valve is provided outside the gun body, a path for liquids such as paint and cleaning liquid from the open / close valve to the discharge nozzle at the tip of the gun is provided. Can be shortened.

  At this time, both the inlet and the outlet provided in the valve unit can be arranged on one surface of the body (invention of claim 2). This facilitates the alignment of the joint between the inlet and outlet and the liquid passage between the valve unit and the unit mounting portion, and the structure of the seal for preventing liquid leakage provided therebetween. Simplification can be achieved.

  By the way, the paint used for painting is a type that can be used up simply, such as a two-component curable paint, and a type that is used while being circulated because precipitation of pigments such as metallic paint tends to occur. There is. Therefore, the valve unit body is provided with a return port for returning the liquid flowing in from the inlet without passing through the on-off valve, and the gun body is connected to the return port to return the liquid to the liquid supply source side. Therefore, it is possible to provide a return passage for the above (invention of claim 3). With this configuration, it is possible to use the coating material that is used while being circulated as described above.

  Also in this case, if the inlet, outlet and return port provided in the valve unit are all arranged on one side of the body (the invention of claim 4), the inlet, outlet and return port are provided. As a result, the position of the joint portion can be easily aligned, and the structure of the seal can be simplified. Furthermore, if the unit mounting portion is configured so that both a valve unit having a return port and a valve unit having no return port can be mounted (the invention of claim 5), the valve unit can be replaced. It becomes possible to correspond to both types of paints.

  In the present invention, the gun body is provided with a plurality of unit mounting portions connected to the plurality of liquid passages, respectively, and the outlet of each valve unit mounted on each unit mounting portion is provided in the gun body. It can comprise so that it may connect with a discharge nozzle via a discharge channel (invention of Claim 6).

  According to this, a plurality of types of paints and cleaning liquids are connected to a plurality of liquid passages, respectively, so that a plurality of types of paints and cleaning liquids are supplied to the gun body, and paint types can be changed (color change) and It becomes possible to perform the painting work while washing. Therefore, the function as a color change valve that is originally provided outside the coating gun can be incorporated in the gun body, and the configuration can be simplified. In addition, compared to the case where a color change valve is provided outside the gun body, the liquid discharge path from the on-off valve to the discharge nozzle at the tip of the gun can be shortened, so that cleaning and color change operations can be performed in a short time. The amount of paint to be discarded and the amount of cleaning liquid to be used can be reduced.

  At this time, the plurality of unit mounting portions can be arranged in a circle with respect to the central axis of the gun body (invention of claim 7), whereby the plurality of valve units can be efficiently arranged. it can. Furthermore, the liquid discharge passage provided in the gun body can be provided so as to be connected to the discharge nozzle while sequentially connecting the outlets of the plurality of valve units (invention of claim 8). Thereby, the configuration of the liquid discharge passage is relatively simple, and the route can be shortened as a whole. At this time, in the case of providing a valve unit for supplying cleaning liquid, if it is arranged in the liquid discharge passage portion located on the most upstream side, the entire liquid discharge passage can be cleaned by flowing the cleaning liquid, which is effective. It becomes.

  In the present invention, the gun body is constructed by incorporating a return opening / closing valve and an air cylinder for driving the opening / closing valve into the body, and includes a return inlet and a return opening / closing valve through which liquid flows. A return unit mounting portion to which a return valve unit having a return outlet for allowing the liquid passed therethrough to flow out is detachably mounted is provided separately from the unit mounting portion, and the valve mounted on the unit mounting portion. It is good also as a structure which provides the connection channel | path which connects the return port provided in the unit, and the said return inflow port (Invention of Claim 9).

  According to this, in the closed state of the on-off valve of the valve unit, the liquid supplied to the valve unit flows from the return port through the connection passage and into the return inlet of the return valve unit. When the return on-off valve of the return valve unit is opened, the liquid that has flowed into the return valve unit flows out from the return outlet and returns through the return passage. Of course, when the on-off valve of the valve unit is opened, the liquid flows out from the outlet of the valve unit and is discharged from the discharge nozzle. Therefore, by driving each on-off valve in the two valve units, it becomes possible to control the discharge from the liquid discharge nozzle and the circulation of the liquid, and use up as described above without replacing parts or the like. It is possible to deal with both the type of liquid and the type of liquid used while being circulated.

  According to the painting gun of the present invention, since the on-off valve and the air cylinder are unitized as a valve unit and are detachably attached to the unit mounting portion of the gun body, the maintainability of the on-off valve portion can be improved. As a result, it is possible to improve the workability of the painting work.

(1) First Embodiment A first embodiment in which the present invention is applied to an automatic gun for electrostatic coating will be described below with reference to FIGS. This embodiment corresponds to claims 1-8.

  First, with reference to FIGS. 2-7, the whole structure of the coating gun which concerns on a present Example is described. As shown in FIGS. 2 and 3, the gun body 11 of the painting gun as a whole has a cylindrical shape in which the tip side (left side in the figure) is slightly depressed, and more specifically, a manifold located on the tip side. 12 and a rear cover 13 made of an insulating material located on the rear side are joined by a cylindrical shroud 14 made of an insulating material.

  Further, a nozzle portion 15 to be described later for discharging paint in a predetermined shape is attached to the tip of the gun body 11 (the manifold 12) so as to be replaceable (detachable). Further, a metal base block 16 is provided on the rear surface side of the rear cover 13. The base block 16 extends downward from the lower end portion and has a bracket 16a integrally therewith. Although not shown, the gun body 11 is attached to the end of the arm of the painting robot or fixedly attached to the painting facility by the bracket 16a.

  As shown in FIG. 7, a power pack (cascade) 17 is disposed in the gun body 11 so as to be located at the center in the axial direction and extend back and forth between the manifold 12 and the rear cover 13. ing. As is well known, the power pack 17 is configured by molding a high voltage generating circuit for generating a DC high voltage with an insulating material. As shown in FIGS. 2 and 3, the power pack 17 is connected to a high-frequency voltage via a connection cable 19 connected to a connector portion 18 provided at the center of the rear end surface (base block 16) of the gun body 11. Is supplied, and the generated DC high voltage (negative high voltage) is output to the output terminal 20 at the tip. The output terminal 20 is electrically connected to a nozzle sheet 21 provided at the center of the tip of the manifold 12, and the nozzle sheet 21 is further connected to a pin electrode 22.

  The nozzle portion 15 includes a discharge nozzle 24 attached to the distal end portion of the manifold 12 via a nozzle joint 23, an air cap 26 attached to the distal end portion of the discharge nozzle 24 via a retainer 25, and the like. Has been. The discharge nozzle 24 has a paint discharge passage 24a that extends in the front-rear direction and discharges paint from the tip, and the paint discharge passage 24a is provided with a tip center portion of the manifold 12 extending in the axial direction. The side liquid discharge passage 27 (see FIG. 2) is connected (communication) via the nozzle sheet 21. At this time, the pin electrode 22 is disposed so as to extend in the center of the paint discharge passage 24a, so that the discharged paint is charged.

  The air cap 26 is provided with an atomizing air outlet 26a that is located immediately outside the tip of the paint discharge passage 24a of the discharge nozzle 24 and that atomizes the discharged paint. A pattern air outlet 26b is provided on the outer peripheral portion for making the cross-sectional shape of the sprayed paint into a predetermined pattern (for example, a flat oval). In the nozzle portion 15, an atomizing air outlet passage 28 communicating with the atomizing air outlet 26a and a pattern air outlet passage 29 communicating with the pattern air outlet 26b are provided. ing.

  At this time, as shown in FIG. 2, the atomizing air outlet passage 28 communicates with the atomizing air passage 30 formed in the manifold 12, and the atomizing air passage 30 is The gun body 11 is connected to a hose connection port 32 provided in the base block 16 via an atomizing air supply pipe 31 extending in the front-rear direction. As shown in FIG. 3, the pattern air outlet passage 29 communicates with the pattern air passage 33 formed in the manifold 12, and the pattern air passage 33 passes through the inside of the gun body 11. A pattern air supply pipe 34 extending in the front-rear direction is connected to a hose connection port 35 provided in the base block 16. A hose is connected to each of the hose connection ports 32 and 35 so that compressed air is supplied from an air supply source (not shown). The atomizing air supply pipe 31 and the pattern air supply pipe 34 are made of an insulating material.

  The gun body 11 is provided with a liquid passage for guiding liquid (paint or cleaning liquid) pumped from a liquid supply source to the discharge nozzle 24 (liquid discharge passage), and the middle portion of the liquid passage. A valve unit 37 including an on-off valve 36 that controls liquid discharge is detachably provided in the manifold 12. In the present embodiment, a plurality of (5 in this case) liquid passages are provided, and the same number (5 in this case) of valve units 37 are provided. Further, in the present embodiment, the gun body 11 is provided with 4 for returning the liquid (paint) supplied to the valve unit 37 to the liquid supply source side corresponding to four liquid passages out of the five liquid passages. A number of return passages are provided.

  First, as shown in FIG. 4, on the rear side of the base block 16, five liquid supply hose connection ports 38 to which a hose for supplying liquid (paint or cleaning liquid) is connected, and for returning the liquid (paint) The four return hose connection ports 39 to which the other hoses are connected are provided alternately in a circle. Further, five driving air hose connection ports 40 corresponding to the liquid supply hose connection ports 38 are also provided on the outer peripheral side thereof. In addition, when it is necessary to distinguish the five liquid supply hose connection ports 38, they are referred to as first to fifth liquid supply hose connection ports 38 in order from the lower left side in the clockwise direction in FIG. 38, (A) to (E) are attached. The return hose connection port 39 and the drive air hose connection port 40 also conform to this.

  At this time, although not shown in detail, in the present embodiment, the first to fourth liquid supply hose connection ports 38 (A) to 38 (D) include a paint tank, a pressure feed pump, a paint mixing device, and the like. The supply source is connected via a hose, and the paint as a liquid is pumped. The fifth liquid supply hose connection port 38 (E) is connected to a cleaning liquid supply source including a tank of a cleaning liquid (for example, a solvent such as thinner) and a pressure feed pump via a hose. As a cleaning liquid, it is pumped.

  Also, although not shown, the first to fourth return hose connection ports 39 (A) to 39 (D) have paints for returning the paints to the respective paint supply sources as necessary. A return hose is connected. The driving air hose connection ports 40 (A) to 40 (E) are connected to hoses for supplying compressed air for driving an air cylinder, which will be described later, from an air supply source (not shown).

  Further, in this embodiment, a replacement air hose connection port 41 is provided in the vicinity of the fifth liquid supply hose connection port 38 (E) of the base block 16. The replacement air hose connection port 41 is connected to a hose for supplying replacement air from an air supply source (not shown). At this time, as shown in FIG. 8, the replacement air hose connection port 41 is connected to the fifth liquid supply hose connection port 38 (E) through the communication path 42 in the base block 16. Connected to a supply pipe (described later), the cleaning liquid in the fifth supply pipe can be replaced with air. The fifth liquid supply hose connection port 38 (E) and the replacement air hose connection port 41 are provided with check valves 43 and 44 for preventing backflow, respectively.

  As shown in FIGS. 2, 3, and 7, the gun body 11 extends in the front-rear direction so as to be spanned between the base block 16 and the manifold 12, and includes first to fifth five pieces. Liquid supply pipes 45 (A) to 45 (E), first to fourth four liquid return pipes 46 (A) to 46 (D) (shown only in FIG. 7), and first to first Fifth five driving air supply pipes 47 (A) to 47 (E) (see FIGS. 6 and 7) are provided.

  As shown in FIG. 6, the base end portions of the first to fifth liquid supply pipes 45 (A) to 45 (E) are the first to fifth liquid supply hose connection ports 38 (A), respectively. To 38 (E), and the tip ends thereof are connected to first to fifth liquid supply paths 48 (A) to 48 (E) provided in the manifold 12, respectively. Base end portions of the first to fourth liquid return pipes 46 (A) to 46 (D) are connected to the first to fourth return hose connection ports 39 (A) to 39 (D), respectively. The tip portions are connected to first to fourth liquid return passages 49 (A) to 49 (D) provided in the manifold 12, respectively. Accordingly, a liquid passage is constituted by the liquid supply pipe 45 and the liquid supply passage 48 and the return passage is constituted by the liquid return pipe 46 and the liquid return passage 49 and the like.

  The base end portions of the first to fifth driving air supply pipes 47 (A) to 47 (E) are respectively connected to the first to fifth driving air hose connection ports 40 (A) to 40 (E). ), And the tip portion is connected to each unit mounting portion (air cylinder of the valve unit 37) described later provided on the manifold 12. Each of the liquid supply pipe 45, the liquid return pipe 46, and the driving air supply pipe 47 is made of an insulating material.

  The manifold 12 is provided with the liquid supply path 48 and the liquid return path 49 described above, and is provided with a unit mounting portion 50 to which each of the five valve units 37 is mounted. Hereinafter, the unit mounting portion 50 and the valve unit 37 will be described in detail. In addition, when it is necessary to distinguish the five unit mounting portions 50 as well, the first to the first in the clockwise direction from the lower left side in FIG. 5 according to the liquid supply hose connection port 38 and the like. 5, the unit mounting portion 50 is denoted by (A) to (E).

  As shown in FIGS. 2, 3, and 5, each unit mounting portion 50 is configured by providing a circular hole extending radially from the outer peripheral surface of the manifold 12 toward the center. As shown in FIG. 5, the five unit mounting portions 50 are arranged substantially evenly with respect to the axial center, that is, arranged in a circle. A female thread portion 50a for mounting the valve unit 37 is formed on the inner peripheral surface of each unit mounting portion 50 on the opening end side (the outer peripheral side portion of the manifold 12). As shown in FIGS. 2, 3, and 9, an insertion hole 50 b (see FIG. 9) into which the positioning pin 51 is inserted is provided in the end portion of the bottom of each unit mounting portion 50. .

  Further, at the bottom of the hole of each unit mounting portion 50, as shown with reference numeral only in FIG. 9, a liquid discharge port 52 is opened at the center of the circular bottom surface, The liquid introduction port 53 is opened at the position. Further, the first to fourth unit mounting portions 50 (A) to (D) return the liquid to a position at an angle of 90 degrees with respect to the center of the bottom (the liquid discharge port 52) with respect to the liquid inlet 53. The mouth 54 is open. The fifth unit mounting portion 50 (E) is configured such that the liquid return port 54 does not exist.

  As shown in FIGS. 2, 3, and 5, each of the liquid discharge ports 52 is connected to the proximal end portion of the distal end side liquid discharge passage 27 via the proximal end side liquid discharge passage 55. Yes. At this time, as shown in FIG. 5, the proximal-side liquid discharge passage 55 includes the fifth unit mounting portion 50 (E), the fourth unit mounting portion 50 (D), and the third unit mounting portion 50 (C ), The second unit mounting portion 50 (B), the first unit mounting portion 50 (A), and the liquid discharge ports 52 of the first unit mounting portion 50 (A). It is provided so as to be connected from the outlet 52 to the proximal end portion of the distal end side liquid discharge passage 27.

  In addition, as shown in FIGS. 2, 3, and 5, the liquid introduction ports 53 are connected to the liquid supply paths 48. At this time, as shown in FIG. 6, each of the liquid supply paths 48 extends from the portion where the tip of the liquid supply pipe 45 is connected to the inside of the manifold 12 toward the radially inner periphery, and then axially ( It bends so as to extend toward the front side, and further extends so as to bend toward the outer peripheral side in the radial direction to reach each liquid inlet 53. Although not shown in detail, each liquid return port 54 is connected to each liquid return passage 49 in the same manner.

  On the other hand, the valve unit 37 is configured as follows. That is, FIG. 1 shows a vertical cross-sectional configuration of the valve knit 37, and the valve unit 37 has a cylindrical shape that fits almost closely into the unit mounting portion 50 as a whole. The valve unit 37 is configured by incorporating the opening / closing valve 36 and an air cylinder 57 for driving the opening / closing valve 36 into a body 56, and an inlet 58 for receiving liquid from the liquid supply path 48 and An outlet 59 is provided for allowing the liquid that has passed through the on-off valve 36 to flow out to the proximal-end-side liquid discharge passage 55.

  The body 56 has a cylindrical shape having an insertion hole 56a through which the rod 60a of the piston 60 constituting the air cylinder 57 is inserted, and a housing 61 is attached to the tip of the body 56 by screwing. The on-off valve 36 includes a valve seat (seat) 62 attached to the center of the front end of the housing 61, and a valve body 63 attached to the front end of the rod 60a of the piston 60.

  At this time, the housing 61 is provided with the inflow port 58 on the front end surface (the surface facing the left side in FIG. 1), and the inflow chamber 64 continuous from the inflow port 58 between the body 56 and the housing 61. Is formed. The outlet 59 is provided at the center of the valve seat 62. Further, as shown only in FIG. 5, a return port 70 connected to the inflow chamber 64 is formed on the front end surface of the housing 61 at a position 90 degrees from the inflow port 58 around the outflow port 59. Yes. Therefore, the inflow port 58, the outflow port 59, and the return port 70 are arranged on one surface (tip surface) of the valve unit 37.

  A groove 61 a into which the positioning pin 51 is fitted is formed on the outer peripheral surface on the front end side of the housing 61. In this description, the valve unit 37 has a return port 70 (a type that can be circulated), but in a non-circulation type, the housing 61 is provided with a return port 70. Not supposed to be. Further, O-rings 68 and 69 as seal members for sealing the periphery of the inflow port 58, the periphery of the outflow port 59, and the periphery of the return port 70 (not shown) are provided on the front end surface portion of the housing 61. It can be installed.

  On the other hand, a cylindrical cylinder portion 56b constituting the air cylinder 57 is integrally provided on the base end side of the body 56, and compressed air from the driving air supply pipe 47 is provided in the cylinder portion 56b. A plurality of air introduction holes 56c for introducing air are formed. Further, an attachment cap 65 is rotatably attached to the base end portion of the body 56 (cylinder portion 56b) and is prevented from being pulled out in the front-rear direction (left-right direction in the figure). On the outer peripheral portion of the cap 65, a male screw portion 65a that is screwed into the female screw portion 50a of the unit mounting portion 50 is formed. On the rear end surface portion of the cap 65, for example, two for inserting a tool. Hole 65b is formed.

  The piston 60 has an outer peripheral surface provided on the inner peripheral surface of the cylinder portion 56b so as to be slidable in the axial direction. At this time, the air introduction is performed between the bottom surface portion on the distal end side of the cylinder portion 56b and the piston 60. An air introduction chamber 66 communicating with the port 56c is formed. A spring 67 is disposed between the piston 60 and the cap 65. Accordingly, an air cylinder 57 is configured by the cylinder portion 56b, the piston 60, the air introduction chamber 66, the spring 67, and the like. Although detailed description (and reference numerals) is omitted, sealing members such as O-rings and U-packings are also provided around the air inlet 56c on the outer periphery of the valve knit 37 and inside the valve unit 37. Is arranged.

  Accordingly, in a normal state, that is, in a state where compressed air is not introduced into the air introduction chamber 66, the piston 60 is at the position shown in FIG. The outlet 59 is closed in close contact with the valve seat 62 (the on-off valve 36 is closed). When compressed air is introduced into the air introduction chamber 66, the piston 60 is displaced to the right in the figure against the spring force of the spring 67, and the valve body 63 is separated from the valve seat 62 to be separated from the outlet 59. Is opened (the on-off valve 36 is opened). When the on-off valve 36 is opened, the liquid (paint and cleaning liquid) that has flowed into the inflow chamber 64 flows out (discharges) from the outflow port 59.

  At this time, in the valve unit 37 of the type having the return port 70 as described above, the liquid supplied (pressure-fed) into the inflow chamber 64 through the inflow port 58 when the on-off valve 36 is closed remains as it is. It is discharged from the return port 70 (circulated). As described above, the valve unit 37 of the type that does not have the return port 70 has no return port 70 in the housing 61 (the return port 70 is in a closed form), and other parts. That is, the outer shape and the like are not different from those of the valve unit 37 having the return port 70. When it is necessary to distinguish between them, the type having the return port 70 is referred to as a valve unit 37 (R), and the type having no return port 70 is referred to as the valve unit 37 (S). Called.

  As shown in FIG. 5, the valve unit 37 configured as described above is detachably attached to each unit mounting portion 50 of the gun body 11. In the present embodiment, the first to fourth unit mounting portions 50 (A) to (D) are each attached with a valve unit 37 (R) of a type having a return port 70, and the fifth unit mounting portion 50. In (E), a valve unit 37 (S) of a type that does not have the return port 70 is attached.

  2 and 3, the valve unit 37 is inserted into the unit mounting portion 50 from the outer peripheral side of the manifold 12, and the positioning pin 51 inserted into the insertion hole 50 b is attached to the housing 61. The valve unit 37 is aligned in the circumferential direction by fitting the formed groove 61a. In this state, by inserting a tool into the hole 65b in the rear end surface portion of the cap 65 and rotating it, the male screw portion 65a on the outer peripheral portion of the cap 65 is screwed (tightened) to the female screw portion 50a of the unit mounting portion 50. Thus, the valve unit 37 is mounted on the unit mounting portion 50. The valve unit 37 can be removed by the reverse procedure to the above.

  2, 3, and 5, the outlet 59 of each valve unit 37 is connected to the liquid discharge port 52 of each unit mounting portion 50 and the inlet 58 of each valve unit 37. Is connected to the liquid inlet 53. In the first to fourth unit mounting portions 50 (A) to (D), the return port 70 of each valve unit 37 is connected to the liquid return port 54. Further, the distal end portion of each driving air supply pipe 47 is connected to the air introduction hole 56 c of each valve unit 37 so that compressed air can be supplied to the air introduction chamber 66.

  Although not shown, in the above-described coating gun, high-frequency voltage is supplied to the power pack 17, atomizing air is supplied from the atomizing air supply source, and pattern air is supplied from the pattern air supply source. Supply, supply of each paint from four paint supply sources (pressure feeding), supply of cleaning liquid from the cleaning liquid supply source, supply of replacement air into the fifth liquid supply pipe 45 (E), five air The supply of each driving air to the cylinder 57 is controlled by a control device including a microcomputer.

  Next, the operation of the above configuration will be described. As described above, the first to fourth liquid supply hose connection ports 38 (A) to 38 (D) of the base block 16 are connected to paint supply sources for supplying different types of paints, respectively. A cleaning liquid supply source is connected to the liquid supply hose connection port 38 (E). In this embodiment, the four types of paints to be supplied are all of a type that is always used while being circulated because precipitation of contained pigments such as metallic paints is likely to occur.

  At this time, in the case of using a paint that is simply used up (non-circulating type) such as a two-component curable paint, the valve unit 37 (R) corresponding to the connection port 38 to which the paint is connected is used. The valve unit 37 (S) may be replaced with a type that does not have the return port 70. Moreover, it is not always necessary to use all of the first to fourth liquid supply hose connection ports 38 (A) to 38 (D). Only the first to third liquid supply hose connection ports 38 (A) to 38 (C) may be used.

  The paint supplied (pressure fed) from the paint supply source passes from the liquid supply hose connection port 38 through the liquid supply pipe 45, further through the liquid supply path 48 of the manifold 12 to the liquid inlet 53, and the valve unit 37 (R). From the inlet 58 to the inflow chamber 64. Here, in a state where the on-off valve 36 of the valve unit 37 (R) is closed, the paint flowing into the inflow chamber 64 passes through the liquid return passage 49 from the return port 70 through the liquid return port 54, and further. The liquid return pipe 46 and the return hose connection port 39 are returned to the paint supply source through the hose. Thereby, the circulation of the paint is performed, and the precipitation and hardening of the pigment in the paint are prevented in advance.

  In this state, when the air cylinder 57 is driven by the supply of driving air and the on-off valve 36 of the corresponding valve unit 37 (R) is opened, the paint flowing into the inflow chamber 64 is discharged from the outflow port 59. From the liquid discharge port 52, the base end side liquid discharge passage 55 and the distal end side liquid discharge passage 27 are sequentially passed to the paint discharge passage 24a of the discharge nozzle 24, and charged from the discharge nozzle 24 while being charged by the pin electrode 22. It is sprayed on the paint.

  At this time, the paint is atomized by the air blown from the atomizing air outlet 26a of the air cap 26, and a predetermined spray pattern of the paint is formed by the air blown from the pattern air outlet 26b. Is done. When the on-off valve 36 is closed, the spraying of paint is stopped. At the time of this painting operation, air is supplied into the fifth liquid supply pipe 45 (E) (the internal cleaning liquid is replaced with air).

  In addition, when changing the type of paint used for painting (color change), a cleaning process for cleaning the liquid discharge passages 55 and 27 and the discharge nozzle 24 is performed. In this cleaning step, the cleaning liquid supply source is driven and the cleaning liquid (thinner) is supplied to the fifth liquid supply pipe 45 (E). In this state, the fifth unit mounting portion 50 (E) When the opening / closing valve 36 of the valve unit 37 (S) attached to the valve is opened, the cleaning liquid passes through the fifth liquid supply path 48 (E) of the manifold 12 as shown in FIG. It flows into the inflow chamber 64 from the inlet 58 of the unit 37 (S).

  Then, the cleaning liquid that has flowed into the inflow chamber 64 is discharged from the outflow port 59, and sequentially passes from the liquid discharge port 52 through the proximal end side liquid discharge passage 55 and the distal end side liquid discharge passage 27 to the paint discharge passage 24 a of the discharge nozzle 24. Then, the ink is discharged from the discharge nozzle 24. At this time, the paint remaining in the liquid discharge passages 55 and 27 and the discharge nozzle 24 is also pushed out and discharged. Further, as shown in FIG. 5, since the cleaning liquid is discharged to the most upstream side of the base end side liquid discharge passage 55, the entire base end side liquid discharge passage 55 can be cleaned.

  When the cleaning process is finished and the supply of the cleaning liquid is stopped, the replacement air is supplied to the fifth liquid supply pipe 45 (E), and the solvent remaining in the solvent supply passage is pushed out from the discharge nozzle 24. Thereafter, the on-off valve 36 of the valve unit 37 (S) is closed. Thereafter, the painting operation using the next type of paint is performed in the same manner as described above. In the cleaning step, it is a matter of course that the supply of high-frequency voltage to the power pack 17 and the supply of atomization and pattern air are stopped.

  Thus, during the above-described painting operation, for example, troubles such as clogging of dust and paint in the on-off valve 36 of the valve unit 37 may occur. When such a trouble occurs, in the configuration of the present embodiment, the apparatus is stopped, the defective valve unit 37 is removed from the unit mounting portion 50, and a new valve unit 37 is attached to the unit mounting portion 50. It only has to be attached (replaced). Thus, maintenance work can be easily performed in a short time.

  Thus, according to the present embodiment, the valve unit 37 in which the on-off valve 36 and the air cylinder 57 are unitized is configured to be detachably attached to the unit mounting portion 50 of the gun body 11. It is possible to easily replace the air cylinder 57 that drives the valve, and it is possible to improve the maintainability of the opening / closing valve 36 and the air cylinder 57, and to improve the workability of the painting work.

  In the present embodiment, the gun body 11 (manifold 12) is provided with a plurality (5) of unit mounting portions 50, and the valve units 37 are mounted on the unit mounting portions 50, respectively. It is possible to perform painting work while changing the paint type (color change) and washing. Therefore, the function of the color change valve 3 that has conventionally been provided separately from the coating gun 1 can be incorporated in the gun body 11, and the configuration can be simplified.

  In addition, compared with the case where a color change valve is provided outside the gun body 11, the path through which the liquid passes from the on-off valve 36 to the discharge nozzle 24 can be greatly shortened, so that cleaning and color change operations can be performed in a short time. The amount of paint to be discarded and the amount of cleaning liquid to be used can be reduced. In addition, since the proximal-side liquid discharge passage 55 is provided so as to be connected to the discharge nozzle 24 while sequentially connecting the outlets 59 of the plurality of valve units 37, the configuration of the liquid discharge passage 55 becomes relatively simple. The path can be shortened as a whole, and further, the entire liquid discharge passage 55 can be cleaned by flowing the cleaning liquid, facilitating cleaning.

  Furthermore, in this embodiment, two types of valve units 37, one with a return port 70 and one without a return port 70, are prepared and can be replaced with the unit mounting portion 50. It can be applied to both types that can be used up simply, such as two-component curable paints, and those that are used while being continuously circulated because the pigments contained therein are likely to precipitate, such as metallic paints. . In the present embodiment, the inlet 58, the outlet 59, and the return port 70 provided in the valve unit 37 are both arranged on one surface of the valve unit 37. It is possible to easily align the joining portions and to obtain an advantage that the seal structure for preventing liquid leakage provided between them can be simplified.

(2) Second Example and Other Examples Next, a second example (corresponding to claim 9) of the present invention will be described with reference to FIGS. The second embodiment also applies the present invention to an automatic gun for electrostatic coating as in the first embodiment. Therefore, the same parts as in the first embodiment are as follows. New illustrations and explanations are omitted, and the reference numerals are also used in common, and the points different from the first embodiment will be mainly described below.

  10 and 11 show the overall configuration of the painting gun according to the present embodiment. Here, the gun body 71 includes a front block 72 located on the distal end side and a rear block 73 located on the rear part thereof. It is configured to be coupled by a cylindrical shroud 74. Similarly to the first embodiment, the nozzle portion 15 including the discharge nozzle 24 and the like is attached to the distal end portion of the gun body 71 (the front block 72) in a replaceable (detachable) manner. On the rear surface side of the rear block 73, a base block 75 having a bracket 75a extending downward is provided.

  As shown in FIG. 14, the power pack 17 is disposed in the gun body 71 below the rear block 73, and the output terminal 20 at the tip of the power pack 17 is pinned via the nozzle sheet 21. 22 is connected. As shown in FIG. 12, the base block 75 is provided with a connector portion 18 to which the connection cable 19 is connected. Further, as shown in FIG. 12, the base block 75 is provided with a hose connection port 32 connected to the atomizing air supply source and a hose connection port 35 connected to the pattern air supply source. ing.

  As shown in FIGS. 13 and 14, the hose connection port 32 is connected to an atomizing air supply path 76 provided in the rear block 73, and is further provided with an atomizing air supply provided in the front block 72. The atomizing air can be supplied to the atomizing air outlet passage 28 in the nozzle portion 15 through the passage 77. The hose connection port 35 is connected to a pattern air supply path 78 provided in the rear block 73 and is further connected to a pattern air supply path 79 provided in the front block 72, through which the nozzle portion 15 is connected. The pattern air can be supplied to the pattern air outlet passage 29.

  As shown in FIGS. 11 and 12, a liquid supply hose connection port is provided on the rear surface side of the base block 75 and connected to the liquid (paint) supply hose located on the left and right sides of the connector portion 18. 38 and a return hose connection port 39 to which a liquid (paint) return hose is connected is provided. The base block 75 is also provided with first and second driving air hose connection ports 80 and 81.

  As shown in FIGS. 11 and 14, the gun main body 71 is located on the left and right sides of the power pack 17, and the liquid supply hose connection port 38 and the liquid supply path 82 ( 11 and FIG. 13), a liquid supply pipe 83 constituting a liquid passage is provided, and the return hose connection port 39 and a liquid return passage 84 (see FIG. 11, FIG. 11) provided in the front block 72 are provided. A liquid return pipe 85 is provided.

  Further, as shown in FIGS. 14 and 10, first and second driving air supply paths 86 and 87 are provided in the rear block 73. The base end portions of the first and second driving air supply passages 86 and 87 are connected to the first and second driving air hose connection ports 80 and 81 (see FIG. 12), respectively, and the distal end portions are the front ends. Two unit mounting portions (air introduction ports 56c of the air cylinder 57 of the valve unit 37), which will be described later, provided in the block 72 are respectively connected.

  As shown in FIG. 13 and the like, the front block 72 is provided with two first and second unit mounting portions 88 and 89 side by side, and these first and second unit mountings are provided. The valve units 37 are detachably attached to the portions 88 and 89, respectively. Of these, the second unit mounting portion 89 is a return unit mounting portion. At this time, as shown in FIGS. 10 and 13, each of the unit mounting portions 88 and 89 is formed by forming a circular hole downward from the upper surface of the front block 72, and the first embodiment described above. Similarly, a female thread portion for mounting the valve unit 37 is formed on the inner peripheral surface on the opening end side, and an insertion hole into which the positioning pin 51 is inserted is provided on the bottom portion.

  In the bottom surface of the hole of the first unit mounting portion 88, a liquid discharge port that is located in the center and is connected to the liquid discharge passage 90 formed in the front block 72 opens, and the side (in FIG. 13) The liquid introduction port connected to the liquid supply path 82 is located on the left side), and further, as shown in FIG. 11, is located on the front side of the liquid discharge port shifted by 90 degrees from the liquid introduction port, A connection port connected to the connection passage 91 formed in the front block 72 is opened.

  As shown in FIGS. 10 and 11, the liquid discharge passage 90 extends downward from the liquid discharge port and then extends forward, and further extends obliquely upward to reach the paint discharge passage 24a (nozzle of the discharge nozzle 24). It is provided so as to be connected to the sheet 21). As shown in FIG. 11, the liquid supply path 82 extends slightly diagonally forward from the tip of the liquid supply pipe 83, and as shown in FIG. 13, it bends and extends slightly upward to enter the liquid inlet. linked. As shown in FIGS. 11 and 13, the connection passage 91 extends downward slightly from the connection port and then bends and extends to the side (second unit mounting portion 89 side).

  On the other hand, at the bottom surface of the hole of the second unit mounting portion 89, a discharge port connected to the liquid return passage 84 is opened at the center thereof, and the connection passage is located at the front side thereof. A connection port leading to 91 is open. The connection passage 91 extends to the side (the second unit mounting portion 89 side) and then bends slightly upward to be connected to the connection port. As shown in FIGS. 11 and 13, the liquid return passage 84 extends slightly downward from the discharge port, then bends and extends slightly diagonally rearward, and is connected to the tip of the liquid return pipe 85.

  And the valve unit 37 (R) of the type having the return port 70 described in the first embodiment is attached to the first unit mounting portion 88. As shown in FIG. 13, when the valve unit 37 (R) is attached to the first unit mounting portion 88, the outlet 59 of the valve unit 37 (R) is connected to the liquid discharge passage 90 via the liquid discharge port. In addition, the inflow port 58 is connected to the liquid supply path 82 through the liquid introduction port. The return port 70 is connected to the connection passage 91 via the connection port. Further, the tip of each of the first driving air supply pipes 86 is connected to one of the air introduction holes 56c of the valve unit 37 (R), so that compressed air can be supplied to the air introduction chamber 66. The

  On the other hand, the second unit mounting portion (return unit mounting portion) 89 is attached with the valve unit 37 (S) of the type not having the return port 70 described in the first embodiment. When the valve unit 37 (S) is attached to the second unit mounting portion 89, the outlet 59 of the valve unit 37 (S) is connected to the liquid return passage 84 via the outlet, and the inlet 58 is provided. Is connected to the connection passage 91 through a connection port. Further, the tip of each second driving air supply pipe 87 is connected to one of the air introduction holes 56c of the valve unit 37 (S), so that compressed air can be supplied to the air introduction chamber 66. The

  Therefore, in the second embodiment, a second unit mounting portion 89 as a return unit mounting portion is provided separately from the first unit mounting portion 88, and the second unit mounting portion 89 is provided. The valve unit 37 (S) attached to the valve functions as a return valve unit. Further, the outlet 59 of the valve unit 37 (S) functions as a return outlet, the inlet 58 functions as a return inlet, and the on-off valve 36 of the valve unit 37 (S) is a return on-off valve. Function as.

  With the above configuration, the paint supplied (pressure-fed) from the paint supply source passes through the liquid supply pipe 83 from the liquid supply hose connection port 38, the liquid supply path 82 of the front block 12, and the first unit mounting portion 88. The valve unit 37 (R) is attached to the inflow chamber 64 through the inlet 58. The paint flowing into the inflow chamber 64 passes from the return port 70 through the connection passage 91 to the inflow chamber 64 from the return inflow port 58 of the valve unit 37 (S) attached to the second unit mounting portion 89. Inflow.

  Here, when driving air is supplied to the air cylinder 57 of the valve unit 37 (R) of the first unit mounting portion 88 through the first driving air supply path 86 and the on-off valve 36 is opened, the inflow chamber The paint that has flowed into 64 is discharged from the outlet 59, reaches the paint discharge path 24 a of the discharge nozzle 24 through the liquid discharge path 90, and is sprayed from the discharge nozzle 24 onto the coating material while being charged by the pin electrode 22. It is done.

  On the other hand, the valve unit 37 of the second unit mounting portion 89 is passed through the second driving air supply passage 87 in a state where the on-off valve 36 of the valve unit 37 (R) of the first unit mounting portion 88 is closed. When driving air is supplied to the air cylinder 57 of (S) and the return on-off valve 36 is opened, the paint that has flowed into the inflow chamber 64 of the valve unit 37 (S) becomes liquid from the return outlet 59. Circulation returning to the paint supply source through the return passage 84 and the liquid return pipe 85 is performed.

  As a result, when using a paint of a type in which the contained pigment is likely to precipitate, such as a metallic paint, the valve unit 37 (S) of the second unit mounting portion 89 is used (the return on / off valve 36). Driving), it is possible to circulate the paint constantly, and to perform painting while preventing precipitation of pigment in the paint. Further, when a paint that is simply used up, such as a two-component curable paint, is used, it can be dealt with by not using the valve unit 37 (S) of the second unit mounting portion 89.

  Therefore, according to the painting gun of the second embodiment, it is possible to cope with both the above-mentioned type of paint and the type of paint that is used while being circulated without replacing parts. Become. Further, similarly to the first embodiment, the valve unit 37 in which the on-off valve 36 and the air cylinder 57 are unitized is configured to be detachably attached to the unit mounting portions 88 and 89 of the gun body 71. Needless to say, the valve 36 and the air cylinder 57 that drives the valve 36 can be easily replaced, and the intended purpose of improving the maintainability of the on-off valve 36 and the air cylinder 57 can be achieved.

  In each of the above embodiments, the present invention is applied to an automatic gun for electrostatic coating. However, a coating gun that is not for electrostatic coating, that is, a gun that does not have the power pack 17 or the pin electrode 22 is also used. Of course, the present invention can be applied. In the above embodiment, five or two valve units are assembled in the gun body. However, one, three, four, or more than six valve units may be provided. In addition, the present invention can be implemented with appropriate modifications within a range not departing from the gist.

The 1st Example of this invention is shown, The expanded vertical side view of a valve unit Longitudinal side view of gun body (cross-sectional view taken along line D-E in FIG. 4) Cross-sectional plan view of gun body (cross-sectional view along line FG in FIG. 4) Rear view of gun body Vertical rear view along line AA in FIG. Longitudinal rear view along line BB in FIG. Longitudinal rear view along line CC in FIG. FIG. 4 is an enlarged longitudinal side view taken along line II of FIG. Enlarged bottom view along line HH in FIG. The 2nd Example of the present invention is shown, a vertical section side view of a gun body (sectional view which meets a LL line of Drawing 12) Cross-sectional plan view of gun body (cross-sectional view taken along line MM in FIG. 12) Rear view of gun body Longitudinal rear view along line JJ in FIG. Longitudinal rear view along line KK in FIG. The figure which shows a conventional example and shows the whole composition of a painting device roughly

Explanation of symbols

  In the drawings, 11 and 71 are gun bodies, 12 are manifolds, 15 are nozzle portions, 16 and 75 are base blocks, 22 are pin electrodes, 24 is discharge nozzles, 24a is a paint discharge passage, 27 is a tip side liquid discharge passage, 36 is an on-off valve, 37 is a valve unit, 45 and 83 are liquid supply pipes, 46 and 85 are liquid return pipes, 48 and 82 are liquid supply paths, 49 and 84 are liquid return paths, and 50, 88 and 89 are unit mounted. , 55 is a base end side liquid discharge passage, 56 is a body, 57 is an air cylinder, 58 is an inlet, 59 is an outlet, 60 is a piston, 64 is an inlet chamber, 66 is an air inlet chamber, 70 is a return port, 72 denotes a front block, 90 denotes a liquid discharge passage, and 91 denotes a connection passage.

Claims (9)

The gun body is provided with a liquid passage for guiding a liquid such as a paint pumped from a liquid supply source to the discharge nozzle, and an opening / closing valve is provided in the middle of the liquid passage, and the discharge nozzle is opened and closed by opening / closing the opening / closing valve. A gun for controlling the discharge of liquid from
The on-off valve and an air cylinder that drives the on-off valve are incorporated in the body, and the inflow port through which the liquid flows in from the paint passage and the liquid that has passed through the on-off valve are discharged to the discharge nozzle side. A painting gun, wherein a valve unit having an outlet is detachably attached to a unit mounting portion provided in the gun body.   The coating gun according to claim 1, wherein an inlet and an outlet provided in the valve unit are both arranged on one surface of the body. The valve unit body is provided with a return port for returning the liquid flowing in from the inlet without passing through the on-off valve,
The coating gun according to claim 1, wherein the gun body is provided with a return passage connected to the return port for returning the liquid to the liquid supply source side.   The coating gun according to claim 3, wherein an inlet and an outlet provided in the valve unit, and the return port are all disposed on one surface of the body.   5. The unit mounting portion is configured so that both a valve unit having the return port and a valve unit having no return port can be mounted. Painting gun.   The gun body is provided with a plurality of unit mounting portions respectively connected to a plurality of liquid passages, and an outlet of each valve unit mounted on each unit mounting portion is a liquid provided in the gun body. The coating gun according to any one of claims 1 to 4, wherein the coating gun is configured to be connected to the discharge nozzle through a discharge passage.   7. The coating gun according to claim 6, wherein the plurality of unit mounting portions are arranged in a circle with respect to a central axis of the gun body.   8. The coating gun according to claim 6, wherein the liquid discharge passage is provided so as to be connected to the discharge nozzle while sequentially connecting outlets of a plurality of valve units. The gun body is constructed by incorporating a return opening / closing valve and an air cylinder for driving the opening / closing valve into the body, and a return inlet for allowing liquid to flow in and the liquid passing through the opening / closing valve to the return passage. A return unit mounting portion to which a return valve unit having a return outlet to be discharged is detachably attached is provided separately from the unit mounting portion,
3. The coating gun according to claim 1, further comprising a connection passage that connects a return port provided in a valve unit attached to the unit attachment portion and the return inflow port.

Images