JP2011045851A - Coating apparatus, coating method, and object to be coated by the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus and a coating method for efficiently coating an object to be coated and an object to be coated by the apparatus and method. <P>SOLUTION: The coating apparatus 1 is for coating an object 8 to be coated and comprises coating material spraying parts 4A and 4B for spraying a coating material to the object 8 to be coated, transporting means 5A and 5B for relatively moving the coating material spraying parts 4A and 4B in directions different from the spraying direction to the object 8 to be coated in a state in which the spraying directions of the coating material spraying parts 4A and 4B are kept constant and a control means 7 for controlling the relative speed of the coating material spraying parts 4A and 4B and the object 8 to be coated corresponding to the distance of the coating material spraying parts 4A and 4B and the object face to be coated of the object 8 to be coated, so that the thickness of coating on the object 8 to be coated becomes approximately uniform. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coating apparatus, a coating method, and an object to be coated.

  As a coating technique for industrial products, for example, a corona charging electrostatic powder coating method as disclosed in Patent Document 1 and a robot coating method as disclosed in Patent Document 2 are known. .

JP 2006-263668 A JP-A-6-7713

  When coating is performed, it is desired that the thickness of the coating film be substantially constant from the viewpoint of maintaining coating quality such as aesthetics of the painted surface. In general, the thickness of the coating film can be adjusted by keeping the distance between the coating gun and the surface to be coated when spraying the paint constant or by adjusting the spray angle.

  When the surface to be painted is not flat, it is necessary to control the movement of the painting gun with a plurality of axes in order to keep the distance between the painting gun and the surface to be painted constant. However, for example, when a plurality of objects to be coated having such a surface to be coated are continuously arranged and coated, the movement of the painting gun becomes extremely complicated, and the number of steps in the painting process increases.

  This invention is made | formed in view of such a subject, and makes it a subject to provide the coating device, the coating method, and its coating material which coat a coating material efficiently.

  In order to solve the above-mentioned problems, the present invention controls the relative speed between the object to be coated and the paint blowing part to a predetermined speed corresponding to the distance between the surface to be coated and the paint blowing part.

  Specifically, a coating apparatus for coating an object to be coated, the paint blowing part spraying paint onto the object to be coated, and the paint blowing part in a state where the paint blowing direction of the paint blowing part is kept constant. Moving means relative to the object to be coated in a direction different from the blowing direction, and the paint blowing part and the object to be coated so that the thickness of the coating film of the object to be coated is substantially uniform. Control means for controlling the relative speed to a predetermined speed corresponding to the distance between the paint blowing portion and the surface to be coated of the object to be coated.

When the distance between the paint blowing portion and the surface to be coated increases, the amount of paint that diffuses to the surroundings increases and the thickness of the coating film decreases. On the other hand, when the distance is reduced, the thickness of the coating film is increased. In order to make the thickness of the coating film substantially constant, it is necessary to make the coating amount sprayed constant. Therefore, in the above-described coating apparatus, attention is paid to the relative speed between the paint blowing portion and the object to be coated in order to keep the amount of paint sprayed constant. That is, if the amount of paint sprayed is constant, the amount of paint sprayed per unit area decreases as the relative speed increases, and the amount of spray increases as the relative speed decreases. The above-mentioned coating apparatus pays attention to such a relationship between the thickness of the coating film and the relative speed, and the control means determines whether the paint blows out according to the distance between the paint blow-out portion and the surface to be painted. The relative speed between the part and the object to be coated is controlled to a predetermined speed. Predetermined speed is the relationship between the distance between the paint blowing part and the surface to be coated so that the thickness of the coating film is substantially constant, and the relative speed between the paint blowing part and the object to be coated. For example, the relative speed decreases as the distance between the paint blowing portion and the surface to be coated increases, and the relative speed increases as the distance decreases.

  Since the relative speed between the paint blowing part and the object to be coated only needs to be adjusted by the operation speed of the moving means for relatively moving these parts, for example, the paint blowing part and the object to be coated are relatively arranged on a plurality of axes. By keeping the distance between the two constant while moving, the object to be coated can be applied more efficiently than in the case where the thickness of the coating film is made constant, and the coating apparatus can be simplified. This coating apparatus is significant for simplifying the coating apparatus because the thickness of the coating film can be made constant even when the paint blowing portion and the object to be coated move relative to each other in one axis.

  The present invention can also be understood from the aspect of the method. For example, in a painting method for painting an object to be coated, the paint blowing part is applied to the article to be coated in a state in which the paint blowing direction of the paint blowing part for spraying the paint onto the object to be coated is kept constant. The relative speed between the paint blowing part and the object to be coated is set so that the thickness of the coating film of the object to be coated is substantially uniform in a direction different from the blowing direction. Relative movement may be performed at a predetermined speed according to the distance from the surface to be coated. Moreover, this invention can also be grasped | ascertained as the to-be-coated object painted by the said coating device or the coating method.

  It becomes possible to efficiently coat the object to be coated.

It is a block diagram of a coating device. It is a figure which shows the conveyance path | route of a to-be-coated object. It is a figure which shows the operation | movement direction of a painting gun. It is operation | movement explanatory drawing of a drive device. It is operation | movement explanatory drawing of a drive device. It is operation | movement explanatory drawing of a drive device. It is a figure which shows the relative positional relationship of a painting gun and a brake shoe. It is a figure explaining operation control of a painting gun. It is a figure explaining operation control of a painting gun. It is a table | surface which shows an experimental result. It is a graph which shows the measurement result of the thickness of a coating film. It is a figure which shows the measurement location of the thickness of a coating film.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a configuration diagram of a coating apparatus 1 according to the first embodiment. As shown in FIG. 1, a coating apparatus 1 includes a housing 2 that accommodates an object to be coated, a transport device 3 that is disposed on a ceiling in the housing 2 and conveys the object to be coated, and paints the object to be coated in the housing 2. Paint guns 4A and B for spraying Further, on the outside of the housing 2, the driving devices 5A and 5B for moving the coating guns 4A and B in the housing 2, the powder supply devices 6A and B for feeding the powder paint to the coating guns 4A and B, and the driving devices 5A and 5B A control device 7 for controlling the operation is provided. In the present embodiment, it is assumed that a brake shoe of an automobile drum brake is painted as an object to be coated. The painting gun 4A paints the web side of the brake shoe, and the painting gun 4B paints the rim side of the brake shoe. In addition, this embodiment is naturally applicable also to to-be-coated objects other than a brake shoe.

  The coating apparatus 1 employs an electrostatic powder coating method, and a powder coating having an electric charge is sprayed from the coating guns 4A and 4B toward an object to be coated. Then, it is electrostatically applied to an object to be electrically grounded. The powder coating that settles in the housing 2 is collected and sent again from the powder supply devices 6A and 6B to the coating guns 4A and 4B. The powder supply devices 6A and 6B are a coating gun in which a powder coating material supplied in a constant amount from a coating tank containing a large amount of powder coating material is mixed with compressed air supplied from a compressed air facility. Send to 4A, B. The housing 2 is provided with exhaust devices (not shown), and the exhaust in the housing 2 is filtered by a bag filter and discharged outside the system by a blower. The bag filter can collect the powder paint contained in the exhaust of the housing 2, thereby preventing the powder paint from being scattered around.

  The conveying device 3 conveys the suspended object to be coated in the housing 2 and carries it in and out of the housing 2. FIG. 2 shows a conveyance path for the object to be coated. The brake shoes 8 that are the objects to be coated are carried in and out in a state where a plurality of the brake shoes 8 are suspended from the application hanger rod 9. Since the application hanger bar 9 is made of stainless steel, the brake shoe 8 that is the object to be coated is electrically grounded via the application hanger bar 9 and the conveying device 3. As shown in FIG. 2, the wall surface of the housing 2 is provided with a carry-in port 10 and a carry-out port 11 for taking in and out the brake shoe 8 while being suspended from the application hanger bar 9. Since the inside of the housing 2 is maintained at a negative pressure by the exhaust devices, the powder paint does not scatter from the carry-in port 10 and the carry-out port 11 to the outside of the housing 2. The brake shoe 8 is carried into the housing 2 through the carry-in port 10 from a facility for performing a degreasing / cleaning process, which is a pretreatment before painting. The brake shoe 8 carried into the housing 2 is conveyed through the housing 2 along the longitudinal direction of the application hanger bar 9 while undergoing a painting process. And it is carried out from the inside of the housing 2 to the heating furnace which bakes the electrostatically applied paint through the carry-out port 11.

The driving devices 5A and 5B are devices for moving the coating guns 4A and B, and the coating guns 4A and B are moved by an actuator having a servo motor (not shown) and a ball screw directly connected thereto. FIG. 3 is a diagram showing the operation direction of the coating guns 4A and 4B. As shown in FIG. 3, when the direction parallel to the longitudinal direction of the coating hanger rod 9 in the housing 2 is taken as the X axis and the direction perpendicular to the ground is taken as the Z axis, the driving device 5A moves the coating gun 4A to X ( The driving device 5B can move the coating gun 4B in the X (+ .−) direction and the Z (+) direction, the Z (+ .−) direction, and the θ _Z (+ .−) direction. It is possible to move in the +/-) direction. The driving device 5A can move the coating gun 4A in the θ _Z (+ · −) direction, but the movable range is limited to a range of ± 30 ° with respect to the Y-axis direction.

The control device 7 includes an arithmetic processing device 12 and a storage device 13, and controls the servo motors of the drive devices 5A and 5B and the electromagnetic valves of the powder supply devices 6A and B. The storage device 13 stores control data in which the operation of the driving devices 5A and 5B is programmed in advance according to the form of the object to be coated, and the arithmetic processing device 12 stores the driving devices 5A and 5B based on the control data. Control the behavior. 4-5 is explanatory drawing of operation | movement of 5 A of drive devices. When the brake shoe 8 suspended from the application hanger rod 9 is carried into the housing 2, the control device 7 controls the actuator of the driving device 5A to change the orientation of the coating gun 4A to θ _Z as shown in FIG. After setting the direction to −30 °, the coating gun 4A is moved in the Z (+) direction, the X (−) direction, the Z (−) direction, and the X (−) direction while opening the solenoid valve and spraying the paint. If this operation is repeated an arbitrary number of times and all the brake shoes 8 are applied, then the direction of the coating gun 4A is set to θ _Z = + 30 °. Then, as shown in FIG. 5, the coating gun 4A is moved in the Z (+) direction, the X (+) direction, the Z (−) direction, and the X (+) direction. Incidentally, theta _Z movement of the spray gun 4A, the shape of the coating hanger bar between the brake shoes 8 are suspended in 9 distance and brake shoes 8, it shall be suitably determined depending on the size or the like.

  When the painting on the web 14 side of the brake shoe 8 is completed with the painting gun 4A, the control device 7 then paints on the rim 15 side of the brake shoe 8 with the painting gun 4B. The brake shoe 8 suspended from the coating hanger rod 9 is transported in the housing 2 by the transport device 3, and is moved from the position where the coating gun 4A is disposed to the coating gun 4B. And the control apparatus 7 controls the actuator of the drive device 5B, and as shown in FIG. 6, Z (+) direction, X (-) direction, Z (-) direction, X (-) Move with direction. When this operation is repeated an arbitrary number of times and all the brake shoes 8 are applied, the electrostatic coating is completed, and the brake shoes 8 coated with the powder coating material are unloaded from the housing 2 by the transport device 3 and sent to the heating furnace.

The relative positional relationship between the painting guns 4A and 4B and the brake shoe 8 when painting is shown in FIG. FIG. 7 is a view of the coating guns 4A and 4B and the brake shoe 8 as viewed from above. The painting gun 4A and the painting gun 4B do not face each other and are disposed at different positions in the housing 2, but for convenience of explanation, they are opposed to each other in FIG. Since the web 14 is a plate-like member joined so as to be orthogonal to the rim 15, when the coating is performed at θ _Z = 0 ° as in the coating gun 4 </ b> B, the coating sufficiently adheres to the web 14 side of the brake shoe 8. do not do. Therefore, the coating gun 4A that coats the web 14 side of the brake shoe 8 has a coating gun 4A in a direction of θ _Z = ± 30 ° so that the coating can sufficiently adhere. On the other hand, on the rim 15 side of the brake shoe 8, the coating gun 4B is painted with θ _Z = 0 ° without adjusting the angle around the Z axis unlike the coating gun 4A.

  Here, the operation control in the Z (+ .−) direction of the coating guns 4A, B performed by the control device 7 will be described. FIG. 8 is a diagram for explaining the operation control of the painting gun 4A, and FIG. 9 is a diagram for explaining the operation control of the painting gun 4B. The brake shoe 8 has a rim 15 that is circumferential in order to press the friction material against the brake drum. Therefore, as shown in FIG. 8, when the coating gun 4A moves in the Z (+ .−) direction, the distance between the tip of the coating gun 4A and the brake shoe 8 changes. That is, when the coating gun 4A is moved uniaxially (Z-axis), the interval when painting the vicinity of the center of the brake shoe 8 becomes wider than the interval when painting the lower and upper ends of the brake shoe 8. . Therefore, if the operation of the coating gun 4A in the Z (+ • −) direction is controlled at a constant speed, the paint is less likely to adhere to the center than the lower and upper ends of the brake shoe 8, and the coating thickness is not uniform. . However, in this control device 7, the moving speed of the coating gun 4A is fast at the upper and lower ends of the brake shoe 8 as shown in the graph of FIG. The movement speed is slow. The control device 7 controls the moving speed of the coating gun 4A so that the speed of the coating gun 4A decreases when the distance between the brake shoe 8 and the coating gun 4A increases, and the relative speed increases when the distance decreases. As a result, the thickness of the coating film becomes uniform. The same applies to the coating gun 4B. As shown in FIG. 9, when the coating gun 4B moves in the Z (+ • −) direction, the interval at which the lower and upper ends of the brake shoe 8 are painted is set to the brake shoe 8. It becomes wider than the interval when painting the vicinity of the center. Therefore, the control device 7 moves the paint gun 4B at a moving speed near the center of the brake shoe 8 as shown in the graph of FIG. I try to increase the speed.

The control device 7 controls the moving speed of the coating guns 4A and B according to the distance between the brake shoe 8 and the coating guns 4A and B. This control is performed by the control data programmed in the storage device 13 in advance. Based on. This control data stipulates the correlation between the distance between the surface to be painted and the paint gun and the moving speed of the paint gun so that the thickness of the coating film is uniform, and was obtained experimentally. It is defined based on data. The control device 7 not only controls the moving speed of the coating guns 4A and B by the control data programmed in advance as described above, but also attaches a distance measuring device or the like to the tip of the coating guns 4A and B, for example. The moving speed of the coating guns 4A and 4B may be controlled based on the data obtained by measuring the distance between the coating guns 4A and 4B and the brake shoe 8 using such a device. In this case, the control is performed such that the moving speed of the coating guns 4A and B in the Z (+ • −) direction is slowed when the interval is wide, and the moving speed is fasted when the distance is narrow.

In order to properly apply a complex-shaped object to be coated, the number of axes on which the coating gun can be moved is increased. Ideally, six axes (X, Y, Z, θ _X , θ _Y , The paint gun can be moved in any direction as long as it can be moved in the [theta] _Z ) direction. However, if the number of actuators is increased, the apparatus becomes complicated and expensive. If it is the coating apparatus 1 which concerns on this embodiment, the thickness of the coating film of a brake shoe can be made substantially constant, without increasing the movable shaft of a coating gun.

Painting gun 4A, the result of the angular speed and theta _Z of B adjusted stepwise to painted trial experiment are shown in the table of FIG. 10. In the table shown in FIG. 10, “AB”, “BC”, and “CD” indicate the Z-axis position of the coating gun, and the symbols A, B, C, and A shown in FIGS. It corresponds to D. As shown in the table of FIG. 10 above, the speed at the lower end portion “AB” and the upper end portion “CD” of the brake shoe and the speed at “BC” near the center are determined as follows: When it changes according to the distance between (Examples 1 to 5) and the case where the speed is constant (Comparative Examples 1 and 2), Examples 1 to 2 are applied rather than the coating states of Comparative Examples 1 and 2. The result that the painting state of 5 was better was obtained. Also, among the Examples 1 to 5, the results of paint state of Example 3 angle theta _Z is ± 30 ° is better than that of the other angles (Comparative Example 1, 2, 4, and 5) is obtained It was.

  Among the samples shown in the table of FIG. 10, the measurement results of the thickness of the coating film on the rim 15 side are shown in FIG. In the graph of FIG. 11, the film thickness measurement position indicated by the horizontal axis corresponds to the position indicated by the reference numeral in FIG. The film thickness per brake shoe is obtained by averaging the film thicknesses measured at five locations. As shown in the graph of FIG. 11, when the coating gun is moved while moving according to the distance between the brake shoe and the painting gun, the coating thickness is more uniform than when coating is performed at a constant speed. Met. From this measurement result, it can be seen that the thickness of the coating film of the brake shoe can be made substantially constant without increasing the movable shaft of the coating gun in the coating apparatus according to the present embodiment.

1. · Coating device 2 ·· Housing 3 · Transport device 4A, B ·· Paint gun 5A, B ·· Drive device 6A, B ·· Powder supply device 7 ·· Control device 8 ·· Brake shoe 9 ·· Application hanger rod 10 .. Carrying port 11 .. Carrying port 12 .. Arithmetic processing device 13.. Storage device 14.

Claims (5)

A painting device for painting an object to be painted,
A paint blowing section for spraying paint onto the object to be coated;
Moving means for moving the paint blowing part relative to the object to be coated in a direction different from the blowing direction in a state where the paint blowing direction of the paint blowing part is kept constant;
The relative speed between the paint blowing part and the object to be coated is set between the paint blowing part and the surface to be coated of the object so that the thickness of the coating film of the object to be coated is substantially uniform. Control means for controlling to a predetermined speed according to the distance,
Painting equipment. The predetermined speed means that the relative speed decreases as the distance increases, and the relative speed increases as the distance decreases.
The coating apparatus according to claim 1. The moving means relatively moves the paint blowing part and the object to be coated on one axis,
The coating apparatus according to claim 1 or 2. A painting method for painting an object to be painted,
In a state where the paint blowing direction of the paint blowing part for spraying the paint on the object to be coated is kept constant, the paint blowing part is applied to the object in a direction different from the blowing direction. The relative speed between the paint blowing portion and the object to be coated is set at a predetermined speed corresponding to the distance between the paint blowing portion and the surface to be coated so that the thickness of the film is substantially uniform. To move relative,
How to paint.   The to-be-coated object coated by the coating apparatus as described in any one of Claims 1-3, or the coating method of Claim 4.

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