JP5330761B2 - Rotary atomizing head type coating equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cleaning efficiency of a rotary atomizing head by stably opening a check valve without exerting an influence on the change of the supply pressure of a cleaning fluid body. <P>SOLUTION: A valve opening degree regulating member 23 for regulating the opening degree when the valve part of the check valve 22 is opened is provided to a position surrounding the check valve 22 opening and closing the cleaning fluid path 21 of a feed tube 17. The valve opening degree regulation member 23 can regulate the opening degree of the valve part of the check valve 22 to a proper degree even when the cleaning fluid material is vigorously supplied from the cleaning fluid path 21. As a result, the cleaning fluid is supplied in an optimum state and the rotary atomizing head 7 is efficiently cleaned. Further, an excess load is prevented from being imposed on the check valve 22 to prevent the damages. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rotary atomizing head type coating apparatus suitable for use in coating an object such as a vehicle body.

  In general, when coating an object to be coated such as a vehicle body, a rotary atomizing head type coating apparatus with good coating efficiency and finish is used. This rotary atomizing head type coating apparatus includes a cover attached to an arm or the like of a painting robot, an air motor provided in the cover, a hollow rotary shaft driven to rotate by the air motor, and a tip of the rotary shaft A rotary atomizing head that is attached to the rotary shaft and rotates together with the rotary shaft; and a coating or cleaning fluid that extends from the tip of the rotary shaft in the axial direction so that the tip side extends into the rotary atomizing head. And a feed tube for discharging the gas.

  The feed tube is formed as a double cylinder by an inner cylinder and an outer cylinder opened at a position retracted from the inner cylinder. A paint passage is formed inside the inner cylinder of the feed tube, and an annular cleaning fluid path is formed between the inner cylinder and the outer cylinder.

  Further, the feed tube made of a double cylinder is provided with a cylindrical check valve extending in the axial direction from the tip of the outer cylinder, and the check valve is made of a resin material or rubber material having elasticity. The valve portion at the tip having a reduced diameter is in close contact with the outer peripheral surface of the inner cylinder (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

JP-A-6-277571 JP-A-10-156222 International Publication No. 2007/083677

  Thus, when the painting operation is performed, the valve portion of the check valve is seated on the outer peripheral surface of the inner cylinder, and the cleaning fluid is prevented from leaking from the cleaning fluid passage. On the other hand, when the cleaning fluid is supplied to the cleaning fluid passage for performing the cleaning operation, the valve portion of the check valve is enlarged by the supply pressure of the cleaning fluid and is separated from the outer peripheral surface of the inner cylinder, and the outer periphery of the inner cylinder is A cleaning fluid can be supplied to the rotary atomizing head from between the surface and the valve portion of the check valve.

  By the way, in the rotary atomizing head type coating apparatus according to each patent document, a check valve made of an elastic resin material or rubber material is provided so as to close the outlet of the cleaning fluid passage. It is possible to prevent the cleaning fluid from leaking from the fluid passage.

  However, since the check valve is formed of an elastic resin material or rubber material, the valve portion of the check valve expands greatly when the supply pressure of the cleaning fluid is high. Here, the rotating shaft, the rotating atomizing head, and the feed tube are arranged with a small gap so that the paint does not flow in between them and adhere. Therefore, if the tip side of the check valve is greatly expanded, the check valve may come into contact with the rotating atomizing head that is rotating at high speed, resulting in leakage of cleaning fluid or unstable cleaning fluid. There exists a problem of causing the fall of the cleaning efficiency by supply, etc.

  In addition, the supply pressure of the cleaning fluid may fluctuate, and the opening degree of the check valve that opens and closes due to the elastic force changes depending on the fluctuation of the supply pressure of the cleaning fluid. For this reason, even when the check valve does not contact the rotary atomizing head or the like, the valve portion of the check valve does not open in a circular shape, and the supply of the cleaning fluid becomes unstable due to a distorted opening. There is a problem that the cleaning efficiency is lowered and the amount of cleaning fluid used is increased.

  Furthermore, when the valve portion of the check valve is excessively expanded by the cleaning fluid, the valve portion may be fully extended and the sealing performance may be deteriorated, resulting in a problem that the life of the check valve is reduced.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a rotary atomizing head by stably opening the check valve without affecting the fluctuation of the supply pressure of the cleaning fluid. Is to provide a rotary atomizing head type coating apparatus that can efficiently wash the water.

A rotary atomizing head type coating apparatus according to the present invention includes a hollow rotary shaft that is rotated by an air motor, a rotary atomizing head that is provided on the tip side of the rotary shaft, and an inner shaft that is provided coaxially within the rotary shaft. A feed tube comprising a cylinder and an outer cylinder, the tip side extending into the rotary atomizing head, a paint passage formed in the inner cylinder of the feed tube and selectively supplied with paint and cleaning fluid; and the feed A cleaning fluid passage formed between an inner cylinder and an outer cylinder of the tube and supplied with a cleaning fluid, and provided at the distal end side of the outer cylinder of the feed tube and is always seated on the outer peripheral surface of the inner cylinder and the cleaning fluid And a cylindrical check valve that opens when the passage is closed and the cleaning fluid is supplied.

In order to solve the above-described problem, the invention adopts the feature that the feed tube is opened at a position where the outlet of the cleaning fluid passage is retracted from the outlet of the paint passage. said the outer cylinder shorter than the barrel so that the tip side of the barrel of the feed tube in a state I To囲front Symbol check valve, the valve opening when said check valve is opened A valve opening degree regulating member that regulates the degree of the valve opening degree regulating member so that the proximal end side is attached to the outer tube of the feed tube and the distal end side is along the outer peripheral surface of the check valve in the opened state. This is because it is formed as an extended regulating cylinder .

According to a second aspect of the present invention, the feed tube is formed such that the outer cylinder is shorter than the inner cylinder so that the feed tube opens at a position where the outlet of the cleaning fluid passage recedes from the outlet of the paint passage. The check valve includes a fixed part fixed to the outer cylinder, a cylindrical part extending from the fixed part to the outer periphery of the inner cylinder toward the distal end side, and a seat on the outer peripheral surface of the inner cylinder provided at the distal end of the cylindrical part. And a restriction cylinder of the valve opening restriction member is provided on the distal end side of the outer cylinder in a state of surrounding the cylinder part of the check valve.

According to a third aspect of the present invention, the restriction cylinder of the valve opening restriction member is provided with a curved inner peripheral surface having an inner diameter that gradually increases from the proximal end side toward the distal end side. The configuration is such that when the valve is opened, the outer peripheral surface thereof is brought into contact.

According to a fourth aspect of the present invention, the rotary atomizing head is provided with a first cleaning fluid outflow passage for supplying the cleaning fluid to the front surface side and a second cleaning fluid outflow passage for supplying the cleaning fluid to the outer peripheral side, The inner tube of the feed tube is provided with a flow dividing member that is located in front of the check valve and separates the cleaning fluid into the first cleaning fluid outflow passage and the second cleaning fluid outflow passage. There is.

According to the first aspect of the present invention, when the cleaning fluid is vigorously supplied from the cleaning fluid passage of the feed tube, the check valve tends to open greatly. However, the distal end side of the barrel of the feed tube check valve in the I's state To囲is provided with a valve opening degree regulating member comprising a regulating cylinder in which the check valve regulates the valve opening degree when the opening Thus, the valve opening of the check valve can be stabilized by the restriction cylinder of the valve opening restriction member. In addition, the check valve can be opened in a circular shape by restricting the valve opening degree by the restriction cylinder of the valve opening restriction member.

As a result, even if the supply pressure of the cleaning fluid fluctuates, the check valve can be opened in a circular shape with a constant valve opening without affecting the fluctuation, and the cleaning fluid can be supplied appropriately. it can. Thereby, a rotary atomization head etc. can be efficiently washed with a washing fluid. Further, by restricting the valve opening degree of the check valve by the restriction cylinder of the valve opening restriction member, the check valve can be prevented from being damaged, and the reliability and life can be improved.

Further , since the feed tube is formed so that the outer cylinder is shorter than the inner cylinder so as to open at a position where the outlet of the cleaning fluid passage recedes from the outlet of the paint passage, the valve opening restriction member is The base end side is attached to the outer tube of the feed tube, and can be formed as a restriction tube extending along the outer peripheral surface of the check valve in a state where the front end side is opened. For this reason, the restriction cylinder of the valve opening restriction member can be provided so as to surround the check valve by using the space on the distal end side of the short outer cylinder.

According to the invention of claim 2 , the feed tube is formed so that the outer cylinder is shorter than the inner cylinder so that the outlet of the cleaning fluid passage opens at a position where the outlet of the cleaning fluid passage recedes from the outlet of the paint passage. A check valve can be provided on the distal end side of the short outer cylinder. Further, the check valve can seat the valve portion on the distal end side of the tube portion on the outer peripheral surface of the inner tube. Furthermore, a restriction cylinder of a valve opening restriction member can be provided on the distal end side of the outer cylinder so as to surround the cylinder portion of the check valve.

According to the invention of claim 3 , the inner peripheral surface of the restriction cylinder of the valve opening restricting member with which the outer peripheral surface abuts when the check valve is opened gradually increases in inner diameter from the proximal end side toward the distal end side. It is formed as a curved inner peripheral surface. As a result, the check valve can be smoothly opened and closed, and the curved inner peripheral surface of the restriction cylinder can prevent stress from being concentrated on a part of the check valve. Life can be extended.

According to the fourth aspect of the present invention, since the inner tube of the feed tube is provided with the flow dividing member located in front of the check valve, the cleaning fluid discharged by opening the check valve is the flow dividing member. Can be divided into the first cleaning fluid passage and the second cleaning fluid passage. Thereby, the front side and the outer peripheral side of the rotary atomizing head can be efficiently cleaned at a time by the cleaning fluid.

  Hereinafter, a rotary atomizing head type coating apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a coating machine cover that covers the outer periphery of a rotary atomizing head type coating apparatus. The coating machine cover 1 is attached to, for example, the tip of an arm (not shown) of a painting robot. And the coating machine cover 1 is formed in a cylindrical shape, and the air motor 2 mentioned later is accommodated in the inside.

  Reference numeral 2 denotes an air motor accommodated in the sprayer cover 1, and the air motor 2 rotates a cylindrical motor casing 2A, an air turbine accommodated in the motor casing 2A, and a rotating shaft 3 described later. It is generally constituted by a hydrostatic air bearing (both not shown) that is pivotally supported. The air motor 2 drives the rotary shaft 3 at a high speed, for example, 3000 to 100,000 rpm by supplying compressed air to the air turbine.

  Reference numeral 3 denotes a rotary shaft that is rotatably supported by a static pressure air bearing of the air motor 2, and the rotary shaft 3 is formed as a cylindrical body having a hollow inside. The rotary shaft 3 has a tip protruding forward of the air motor 2, and a male screw 3A for screwing the rotary atomizing head 7 is engraved on the outer periphery of the tip. Further, the base end side of the rotating shaft 3 is attached to the air turbine of the air motor 2.

  Reference numeral 4 denotes a shaping air ring attached to the tip of the coating machine cover 1. The shaping air ring 4 is formed in a cylindrical shape whose front side is recessed in a bowl shape. In addition, a large number of air ejection holes 4A (only two are shown) are formed in the circumferential direction at the distal end portion of the shaping air ring 4 and each air ejection hole 4A is connected to an air source via the shaping air passage 5. (Not shown). The air ejection hole 4A ejects shaping air for controlling a spray pattern of paint particles sprayed from a rotary atomizing head 7 described later.

  Further, the shaping air ring 4 is formed with a large number of diffusion air ejection holes 4B (only two are shown) in the circumferential direction, located on the inner diameter side of each air ejection hole 4A. This diffusion air ejection hole 4B is located on the rear side of the outer peripheral surface 8C of the atomizing head main body 8 to be described later. Further, each diffusion air ejection hole 4B is opened at a position near the outer peripheral side of the annular guide 16 described later.

  The diffusion air ejection hole 4 </ b> B uses the air supplied from the air source via the diffusion air passage 6 as diffusion air, and directs this diffusion air toward the vicinity of the outer peripheral end of the annular guide 16 from the rear side of the atomizing head main body 8. Spray. Thereby, the diffusion air diffuses and spreads on the outer peripheral surface 8C while pressing the cleaning fluid flowing out from the second cleaning fluid outflow passage 15 against the outer peripheral surface 8C of the atomizing head main body 8, and has a uniform film thickness. Guide toward the tip of the outer peripheral surface 8C.

  Reference numeral 7 denotes a rotary atomizing head attached to the tip of the rotary shaft 3, and the rotary atomizing head 7 sprays the supplied paint toward the object to be coated while atomizing it. Further, as shown in FIG. 1, the rotary atomizing head 7 is roughly constituted by an atomizing head main body 8, a paint reservoir 11, a paint thinning surface 12, a hub member 14, an annular guide 16 and the like which will be described later.

  8 is an atomizing head main body comprising a hollow bell cup formed in a bell shape or a cup shape. The atomizing head main body 8 is positioned on the rear side and is attached to the rotary shaft 3 with an attaching portion 8A. It is comprised by the bell-shaped expansion part 8B which is located in the part side and expanded toward the front. Here, the attachment portion 8A is formed in a cylindrical shape, and a female screw 8D that is screwed into a male screw 3A provided at the tip of the rotating shaft 3 is formed on the inner peripheral side.

  Reference numeral 9 denotes an attachment bottom portion which is located on the inner peripheral side of the atomizing head main body 8 and forms the bottom portion of the attachment portion 8A. The attachment bottom portion 9 is a rear side which is a boundary portion between the attachment portion 8A and the bell-shaped widened portion 8B. At the position, it projects inwardly (reduced diameter). Further, a second cleaning fluid outflow passage 15 to be described later is formed on the front side of the attachment bottom portion 9. A cylindrical projection 9A is provided on the inner diameter side (center portion) of the mounting bottom 9 so as to enter the opening on the tip end side of the rotating shaft 3, and the inner peripheral surface of the cylindrical projection 9A is a feed tube. 17 is a nozzle insertion hole 9B through which the tip end side is inserted.

  Reference numeral 10 denotes an intermediate partition wall provided at the intermediate position in the axial direction of the atomizing head main body 8 so as to face the mounting bottom 9. The intermediate partition wall 10 has a second cleaning fluid outflow passage 15 and a paint reservoir 11 which will be described later. It is formed as a separating wall board. Further, a tube insertion hole 10 </ b> A through which the inner tube 18 of the feed tube 17 is inserted with a gap is formed on the inner peripheral side (center portion) of the intermediate partition wall 10. Further, the middle of the intermediate partition wall 10 protrudes forward in order to prevent the paint in the paint reservoir 11 from entering the rotary shaft 3.

  A paint reservoir 11 is located on the inner peripheral side of the atomizing head main body 8 and is defined between the intermediate partition wall 10 and a hub member 14 described later. The paint reservoir 11 is formed as a deep dish-like space surrounded by the inner peripheral surface of the atomizing head main body 8, the front surface of the intermediate partition wall 10, and the rear surface of the hub member 14. The paint reservoir 11 is a space for temporarily storing the paint or cleaning fluid discharged from the inner cylinder 18 and diffusing these.

  Reference numeral 12 denotes a paint thinning surface provided from the front side of the paint reservoir 11 to the front end of the atomizing head main body 8, and the paint thinning surface 12 is formed to expand in a disc shape. Further, the tip of the paint thinning surface 12 is a discharge edge 12A that discharges the thinned paint. The paint thinning surface 12 is for thinning the paint flowing out from the paint reservoir 11 and spraying it as paint particles from the discharge edge 12A.

  Reference numeral 13 denotes a first cleaning fluid outflow passage provided in the atomizing head main body 8, and the cleaning fluid outflow passage 13 is provided in a tube insertion hole 10 </ b> A of the intermediate partition wall 10, and an inner cylinder 18 of a feed tube 17 described later. It is formed as an annular passage between. And the 1st washing fluid outflow passage 13 distribute | circulates the washing fluid for washing | cleaning the coating material pool 11, the coating-film thinning surface 12, the hub member 14, etc. to the front side.

  A hub member 14 is provided at the center of the front side of the atomizing head main body 8. The hub member 14 is formed in a substantially disc shape and closes the inner periphery of the atomizing head main body 8 to define the paint reservoir 11. ing. Here, on the outer peripheral side of the hub member 14, a large number of paint outflow holes 14 </ b> A through which paint or cleaning fluid flows out to the paint thinning surface 12 of the atomizing head body 8 are arranged in a circular shape. Further, a plurality of outflow openings 14B (only two are shown) are provided on the front surface side of the hub member 14 to allow the cleaning fluid to flow out.

  Reference numeral 15 denotes a second cleaning fluid outflow path provided in the atomizing head main body 8. The cleaning fluid outflow path 15 opens between the attachment bottom portion 9 and the intermediate partition wall 10 on the inflow side, and the atomizing head on the outflow side. Opened to the outer peripheral surface 8 </ b> C of the main body 8. Here, the second cleaning fluid outflow passage 15 supplies a cleaning fluid for removing the paint adhering to the outer peripheral surface 8C of the atomizing head main body 8. For example, the second cleaning fluid outflow passage 15 is formed by a gap passage extending annularly or radially. Is formed.

  Reference numeral 16 denotes an annular guide which is attached to the outer peripheral side of the atomizing head main body 8 adjacent to the rear side of the second cleaning fluid outflow passage 15. The annular guide 16 has an inner peripheral side inclined toward the rear side and an outer peripheral side inclined toward the front side toward the outer peripheral surface 8 </ b> C of the atomizing head main body 8. The annular guide 16 guides the cleaning fluid that flows out from the second cleaning fluid outflow passage 15 and is scattered in the radial direction toward the front side toward the outer peripheral surface 8 </ b> C of the atomizing head main body 8.

  Next, reference numeral 17 denotes a feed tube provided extending in the axial direction within the rotary shaft 3. As shown in FIG. 2, the feed tube 17 includes a long inner cylinder 18 that is positioned at the center of rotation and whose tip extends into a paint reservoir 11 of the rotary atomizing head 7, which will be described later. It is formed as a double cylinder from an outer cylinder 19 provided coaxially on the outer peripheral side.

  Here, the outer cylinder 19 is formed shorter than the inner cylinder 18 so as to open at a position where an outlet 21A of the cleaning fluid passage 21 is retracted from an outlet 20A of the paint passage 20 described later. The distal end side of the outer cylinder 19 is reduced in diameter, and a male screw 19A is engraved on the outer periphery thereof. A check valve 22 and a valve opening restricting member 23 described later are attached to the distal end side of the outer cylinder 19.

  Reference numeral 20 denotes a paint passage formed inside the inner cylinder 18. The paint passage 20 supplies paint or cleaning fluid from the outlet 20A on the tip side toward the rotary atomizing head 7 (paint reservoir 11). . That is, the paint passage 20 discharges the paint selected from a plurality of colors toward the rotary atomizing head 7 when painting the object. On the other hand, when cleaning the previous color paint after painting, air, thinner, etc. are selectively distributed to discharge and wash the paint.

  In addition, a paint valve (not shown) is provided in the middle of the paint passage 20, and the paint valve is opened when the paint is supplied and closed when the supply of the paint is stopped. And the paint channel | path 20 is connected to the color change valve apparatus (all are not shown) via piping, a valve body, etc., for example. The color changing valve device selectively supplies a plurality of colors of paint, cleaning air, and cleaning fluid including cleaning thinner, and includes a manifold and a plurality of valve devices attached to the manifold. .

  Reference numeral 21 denotes a cleaning fluid passage having an annular cross section formed between the inner cylinder 18 and the outer cylinder 19 of the feed tube 17. The cleaning fluid passage 21 supplies cleaning fluid such as thinner and air from the outlet 21 </ b> A on the tip side toward the rotary atomizing head 7. The cleaning fluid passage 21 is connected to a cleaning fluid supply source (both not shown) via, for example, piping, a valve body, and the like.

  A check valve 22 is provided on the distal end side of the outer cylinder 19 constituting the feed tube 17. The check valve 22 is formed in a cylindrical shape using a resin material having elasticity (spring property), a rubber material, for example, a fluorine resin material. The check valve 22 normally closes the outlet 21A of the cleaning fluid passage 21 by an elastic force, and opens against the supply pressure when the cleaning fluid is supplied.

  That is, the check valve 22 is positioned between the fixed portion 22A that is positioned on the proximal end side in the axial direction and is attached to the distal end side of the outer cylinder 19 by a valve opening restriction member 23 described later, and the outer peripheral surface of the inner cylinder 18. While forming a gap in the radial direction, a cylindrical portion 22B extending from the fixed portion 22A toward the distal end of the outer periphery of the inner cylinder 18, and a reduced diameter at the distal end side of the cylindrical portion 22B are provided. It is composed of an annular valve portion 22 </ b> C that is separated from and seated on the outer peripheral surface of the inner cylinder 18 by expanding and contracting.

  The check valve 22 can seal the outlet 21A of the cleaning fluid passage 21 in a gas-liquid tight manner by seating the elastic valve portion 22C on the outer peripheral surface of the inner cylinder 18 over the entire circumference. . On the other hand, when the cleaning fluid is supplied into the cleaning fluid passage 21, the check valve 22 displaces the valve portion 22C radially outward by the supply pressure of the cleaning fluid, as shown in FIG. By doing so, the outlet 21A of the cleaning fluid passage 21 can be opened.

  Next, the valve opening degree regulating member 23 provided on the front end side of the feed tube 17 in order to regulate the valve opening degree when the check valve 22 is opened will be described.

  That is, reference numeral 23 denotes a valve opening restricting member provided on the distal end side of the feed tube 17. The valve opening restricting member 23 is disposed at a position surrounding the check valve 22 on the distal end side of the feed tube 17, for example, at the distal end opening position of the rotary shaft 3 and inside the nozzle insertion hole 9 </ b> B of the mounting bottom 9. The valve opening restricting member 23 increases the valve opening so that the valve portion 22C does not open more than necessary when the tip end side of the cylindrical check valve 22 is opened and opened. It regulates at a predetermined position before becoming. Further, the valve opening restriction member 23 can open the valve portion 22C in a circular shape.

  Further, as shown in FIGS. 2 to 4, the valve opening restricting member 23 includes a nut-like screwed portion 23A that is positioned on the base end side and screwed to the male screw 19A of the outer cylinder 19, and the screwed portion. It is formed in a stepped cylindrical shape by a regulating cylinder 23B extending from the portion 23A to the distal end side along the outer peripheral surface of the cylindrical portion 22B of the check valve 22. The front end position (length dimension) of the regulating cylinder 23B is set to be substantially the same position as the front end position of the valve bottom 22C of the check valve 22 and the mounting bottom 9 constituting the rotary atomizing head 7, for example.

  Further, a diameter-reduced step portion 23C is formed on the inner peripheral side of the regulating cylinder 23B so as to be located on the proximal side in the axial direction. Thus, the valve opening restricting member 23 engages the outer peripheral side of the fixing portion 22A of the check valve 22 with the reduced diameter step portion 23C, and in this state, the screwing portion 23A is screwed to the male screw 19A of the outer cylinder 19. By doing so, the check valve 22 can be attached to the front end side of the outer cylinder 19 together.

  Here, when the check valve 22 is opened, the inner peripheral surface 23D of the regulating cylinder 23B comes into contact with the cylinder portion 22B to the valve portion 22C. The inner peripheral surface 23D is a straight inner peripheral surface 23D1 whose base end side extends straight with an inner diameter dimension substantially the same as the outer dimension of the cylindrical portion 22B of the check valve 22.

  On the other hand, the inner peripheral surface 23D has a curved inner peripheral surface 23D2 that is curved so that the inner diameter dimension gradually increases toward the distal end side from the axially intermediate portion to the distal end portion. Then, the curved inner peripheral surface 23D2 has a gentle curved surface from the intermediate portion in the axial direction to the tip end portion of the inner peripheral surface 23D, so that when the check valve 22 is opened as shown in FIG. This prevents stress from concentrating on the part and bending.

  Further, the curved inner peripheral surface 23D2 is in contact with the distal end side of the cylindrical portion 22B and the outer peripheral surface of the valve portion 22C, and the valve opening of the check valve 22 when supplying the cleaning fluid is set to an appropriate value. In this case, the appropriate valve opening degree of the check valve 22 is, for example, that the valve portion 22C does not open excessively so that cracks and a decrease in elastic force do not occur, and the discharged cleaning fluid flows to the flow dividing member 24 described later. The valve opening degree is a flow rate and a flow velocity at which the first cleaning fluid outflow passage 13 and the second cleaning fluid outflow passage 15 are separated by collision.

  Reference numeral 24 denotes a flow dividing member provided on the outer periphery on the front end side of the inner cylinder 18 constituting the feed tube 17. The diversion member 24 appropriately diverts the cleaning fluid supplied from the cleaning fluid passage 21 into the first cleaning fluid outflow passage 13 and the second cleaning fluid outflow passage 15. The flow dividing member 24 is disposed on the front side (tip side) from the position of the check valve 22 and protrudes in the radial direction from the outer peripheral surface of the inner cylinder 18, for example, has a shape such as a bowl shape, a fan shape, a convex spherical shape, or the like. It is formed as one or a plurality of protrusions.

  The rotary atomizing head type coating apparatus according to this embodiment has the above-described configuration. Next, the painting operation and the cleaning operation will be described.

  First, the case of performing a painting operation for spraying a paint on an object to be coated will be described with reference to FIGS. 1 and 2. In this painting operation, the rotary atomizing head 7 is rotated together with the rotary shaft 3 by the air motor 2 at a high speed, for example, 3000 to 100,000 rpm. In this state, when the paint supplied from the color change valve device is supplied from the inner cylinder 18 of the feed tube 17 to the paint reservoir 11 of the rotary atomizing head 7, the paint is diffused while staying in the paint reservoir 11. The paint diffused in the paint reservoir 11 passes through the paint outflow hole 14 </ b> A of the hub member 14 and flows out to the paint thinning surface 12 of the atomizing head main body 8. Further, the paint is uniformly thinned on the paint thinning surface 12 and sprayed as paint particles from the discharge edge 12A.

  At this time, for example, a high voltage is applied to the rotary atomizing head 7 and electric lines of force are formed from the rotary atomizing head 7 toward the workpiece connected to the ground. The sprayed paint particles fly along the lines of electric force and are applied to the object to be coated.

  Further, during the painting operation, the valve portion 22C of the check valve 22 is in close contact with the outer peripheral surface of the inner cylinder 18, and the outlet 21A of the cleaning fluid passage 21 is closed in a gas-liquid tight manner, so that it remains in the cleaning fluid passage 21. It is possible to prevent accidental dripping of the cleaning fluid.

  Next, a cleaning operation for cleaning the forecolor paint remaining on and adhering to the feed tube 17 and the rotary atomizing head 7 after the painting operation is completed will be described with reference to FIG.

  First, since the previous color paint remains in the paint passage 20 in the inner cylinder 18, when the paint passage 20 is cleaned, the rotary atomizing head 7 is rotated at a high speed while the air is discharged from the color change valve device. By alternately supplying the thinner and the thinner, the liquid contact surface on which the paint adheres is washed while discharging the paint in the paint passage 20.

  On the other hand, when the rotary atomizing head 7 is cleaned, cleaning fluid such as thinner and air is supplied from the cleaning fluid passage 21 of the feed tube 17 with the rotary atomizing head 7 rotated at high speed. At this time, the valve portion 22C of the check valve 22 is expanded in diameter by the supply pressure of the cleaning fluid and opened. As a result, the cleaning fluid discharged from the check valve 22 circulates forward along the outer peripheral surface of the inner cylinder 18 and collides with the flow dividing member 24, and the first cleaning fluid outflow path 13 and the second cleaning fluid outflow. An appropriate ratio is supplied to the channel 15.

  Then, the cleaning fluid supplied to the first cleaning fluid outflow passage 13 sequentially flows from the coating material reservoir 11 through the coating material outflow hole 14A of the hub member 14, the coating material thinning surface 12 and the like, and the coating material adhered to these liquid contact surfaces. Can be washed. Further, the cleaning fluid supplied to the second cleaning fluid outflow passage 15 can clean the paint adhering to the outer peripheral surface 8 </ b> C of the atomizing head main body 8.

  At the time of this cleaning operation, the valve opening degree regulating member 23 is brought into contact with the opened check valve 22 to regulate the valve opening degree at a predetermined position so that the check valve 22 does not open more than necessary. Further, by bringing the check valve 22 into contact with the inner peripheral surface 23D of the regulation cylinder 23B, the valve portion 22C can be opened in a circular shape. Thereby, the check valve 22 can be opened at a constant valve opening, the cleaning fluid can be supplied uniformly over the entire circumference, and damage to the check valve 22 can be prevented.

  Thus, according to the present embodiment, the valve opening that regulates the valve opening when the check valve 22 is opened at a position surrounding the check valve 22 that opens and closes the cleaning fluid passage 21 of the feed tube 17. The degree regulating member 23 is provided. Therefore, even when the check valve 22 attempts to open excessively as in the case where the cleaning fluid is vigorously supplied from the cleaning fluid passage 21, the valve opening restriction member 23 opens the valve portion 22C of the check valve 22 to an appropriate valve. The valve can be stably opened at the opening.

  As a result, even when the supply pressure of the cleaning fluid fluctuates during the cleaning operation of the rotary atomizing head 7 or the like, the valve opening restriction member 23 keeps the valve portion 22C of the check valve 22 constant without affecting the fluctuation. It can be opened at a valve opening of. Moreover, the valve opening restriction member 23 can open the valve portion 22C of the check valve 22 in a circular shape. Thereby, at the time of a cleaning operation, the cleaning fluid can be supplied in a uniform state from the valve portion 22C of the check valve 22, and the rotary atomizing head 7 and the like can be efficiently cleaned with the cleaning fluid. Further, by restricting the valve opening degree of the check valve 22 by the valve opening restriction member 23, when the check valve 22 is opened, stress is partially concentrated, bent, or extended. And reliability and lifetime can be improved.

  Further, the feed tube 17 has an outer cylinder 19 shorter than the inner cylinder 18 so as to open at a position where the outlet 21 </ b> A of the cleaning fluid passage 21 is retracted from the outlet 20 </ b> A of the paint passage 20. Accordingly, a valve opening degree regulating member is used so as to surround the cylindrical portion 22B and the valve portion 22C of the check valve 22 in the space on the distal end side of the short outer cylinder 19 by utilizing the radial step between the inner cylinder 18 and the outer cylinder 19. 23 can be provided, and these can be arranged efficiently.

  On the other hand, the valve opening restriction member 23 has a curved inner peripheral surface 23D2 whose inner diameter gradually increases from the proximal end side toward the distal end side on the inner peripheral surface 23D of the restriction cylinder 23B that contacts when the check valve 22 is opened. Is forming. Thereby, the curved inner peripheral surface 23D2 can smoothly open and close the check valve 22, and the curved inner peripheral surface 23D2 prevents stress from concentrating on a part of the check valve 22. The service life of the check valve 22 can be extended.

  Furthermore, since the inner cylinder 18 of the feed tube 17 is provided with a flow dividing member 24 located in front of the check valve 22, the cleaning fluid discharged by opening the check valve 22 is discharged by the flow dividing member 24. The first cleaning fluid outflow path 13 and the second cleaning fluid outflow path 15 can be divided. Thereby, the outer peripheral side and front side of the rotary atomizing head 7 can be efficiently cleaned at a time by the cleaning fluid.

  In the embodiment, the flow dividing member 24 is provided on the outer periphery on the tip side of the inner cylinder 18 constituting the feed tube 17, and the flow dividing member 24 has a shape such as a bowl shape, a fan shape, or a convex spherical shape protruding in the radial direction. The case where the protrusion is formed as one or a plurality of protrusions forming the above has been described as an example. However, the present invention is not limited to this. For example, as in the modification shown in FIG. 5, the flow dividing member 31 includes a wall member 31 </ b> A having a triangular cross section that protrudes radially outward from the inner cylinder 18, and the wall member 31 </ b> A. And a through hole 31B provided so as to penetrate in the axial direction. Thereby, the flow dividing member 31 can supply the cleaning fluid toward the first cleaning fluid outflow path 13 through the through-hole 31B, and supply the cleaning fluid toward the second cleaning fluid outflow path 15 through the wall member 31A. Can do.

It is a longitudinal cross-sectional view which shows the rotary atomization head type coating device by embodiment of this invention. It is a longitudinal cross-sectional view of the principal part expansion which shows the A section in FIG. 1 in the state which closed the check valve. It is the longitudinal cross-sectional view of the principal part expansion which looked at the state which opened the check valve from the same position as FIG. It is a longitudinal cross-sectional view which shows a valve opening restriction member alone. It is a longitudinal cross-sectional view of the principal part expansion which shows the rotary atomization head type coating device by the modification of this invention.

Explanation of symbols

2 Air motor 3 Rotating shaft 7 Rotating atomizing head 8 Atomizing head main body 9 Mounting bottom 10 Intermediate partition 11 Paint reservoir 12 Paint thinning surface 13 First cleaning fluid outflow path 14 Hub member 15 Second cleaning fluid outflow path 17 Feed Tube 18 Inner cylinder 19 Outer cylinder 20 Paint passage 20A, 21A Outlet 21 Washing fluid passage 22 Check valve 22A Fixing portion 22B Tube portion 22C Valve portion 23 Valve opening restricting member 23A Screwing portion 23B Restriction tube 23C Reduced diameter step portion 23D Inner peripheral surface 23D1 Linear inner peripheral surface 23D2 Curved inner peripheral surface 24, 31 Flow dividing member

Claims (4)

A hollow rotary shaft rotated by an air motor, a rotary atomizing head provided on the tip side of the rotary shaft, an inner cylinder and an outer cylinder provided coaxially in the rotary shaft, and the tip side of the rotary fog A feed tube extending into the chemical head, a paint passage formed in the inner cylinder of the feed tube and selectively supplied with paint and cleaning fluid, and formed between the inner cylinder and the outer cylinder of the feed tube A cleaning fluid passage to which cleaning fluid is supplied, and when the cleaning fluid is supplied by being normally seated on the outer peripheral surface of the inner tube and closing the cleaning fluid passage , provided at the distal end side of the outer tube of the feed tube In a rotary atomizing head type coating device comprising a cylindrical check valve that opens to
The feed tube is formed so that the outer cylinder is shorter than the inner cylinder so as to open at a position where the outlet of the cleaning fluid passage is retracted from the outlet of the paint passage,
The distal end of the outer tube of the feed tube before Symbol check valve in I but state To囲, provided the valve opening degree regulating member for regulating the valve opening degree when the check valve is opened,
The valve opening restricting member is formed as a restricting cylinder that is attached to the outer cylinder of the feed tube on the base end side and extends along the outer peripheral surface of the check valve in a state where the distal end side is opened. Rotary atomizing head type coating equipment. The feed tube is formed so that the outer cylinder is shorter than the inner cylinder so as to open at a position where the outlet of the cleaning fluid passage is retracted from the outlet of the paint passage,
The check valve includes a fixed part fixed to the outer cylinder, a cylindrical part extending from the fixed part to the outer periphery of the inner cylinder toward the distal end, and an outer peripheral surface of the inner cylinder provided at the distal end of the cylindrical part. It consists of a valve part to be seated,
2. The rotary atomizing head type coating apparatus according to claim 1, wherein the restriction cylinder of the valve opening restriction member is provided on a front end side of the outer cylinder in a state of surrounding a cylinder portion of the check valve. The regulating cylinder of the valve opening regulating member is provided with a curved inner circumferential surface whose inner diameter dimension gradually increases from the proximal end side toward the distal end side, and the curved inner circumferential surface is provided when the check valve is opened. rotary atomizing head type coating apparatus according to claim 1 or 2 comprising a configuration to abut the outer peripheral surface thereof. The rotary atomizing head is provided with a first cleaning fluid outflow passage for supplying the cleaning fluid to the front side and a second cleaning fluid outflow passage for supplying the cleaning fluid to the outer peripheral side ,
The inner cylinder prior Symbol feed tube, be provided with a dividing member to divert the cleaning fluid located on the front side than the position of the check valve into a first cleaning fluid outflow path and the second cleaning fluid outflow path The rotary atomizing head type coating apparatus according to claim 1, 2, or 3.

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