Coating device

Abstract

To suppress an increase in the film thickness at a rotational axis portion of a target object and its vicinity.SOLUTION: A coating device includes: a base 2 that fixes a target object W with its coated surface directed upward and rotates the target object W about a rotational axis 20; a spray unit 3 directed toward the base 2; a moving mechanism 4 that is provided in at least one of the base and the spray unit to move the spray unit relative to the rotating coated surface; and a distance adjustment mechanism 5 for changing a distance between the spray unit 3 and the coated surface. The distance adjustment mechanism drives the base or the spray unit such that the distance between the spray unit and the coated surface becomes longer as the spray unit approaches the rotational axis from the outer periphery side of the coated surface by the moving mechanism.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed herein belongs to the technical field related to coating devices.

Background Art

[0002] Various coating devices for spraying a coating material onto a rotating object are known. For example, Patent Document 1 discloses a coating device that sprays a coating material from above the inner peripheral side of a rotating substrate and causes it to flow from the inner peripheral side to the outer peripheral side of the substrate by centrifugal force due to rotation. In addition to such a configuration, Patent Document 2 discloses a coating method in which the rotation speed of the object is made different between the discharge time of the first coating material and the discharge time of the second coating material. Further, Patent Document 3 discloses a method for manufacturing a pattern film that forms a pattern with a coating material, in which a table on which an object is fixed is movable in the X-axis and Y-axis directions, and a nozzle for discharging the coating material is movable in the Z-axis direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in such a coating device, there is a problem that the inner peripheral side closer to the rotation axis of the object and the outer peripheral side farther from the rotation axis are coated thicker due to the difference in the moment of inertia. However, the above patent documents do not disclose means for solving this as a problem.

[0005] The technology disclosed herein has been made in view of such a point, and an object thereof is to provide a coating apparatus and a coating method that suppress an increase in film thickness at the rotating shaft portion of an object and its periphery.

Means for Solving the Problems

[0006] In order to solve the above problems, the technology disclosed herein is a coating apparatus that sprays a coating material onto a surface to be coated of a rotating object to form a coating film, comprising: a base that fixes the object with the surface to be coated directed upward and rotates the object about a rotation axis; a spray portion that directs toward the base; a moving mechanism provided on at least one of the base and the spray portion that relatively moves the spray portion with respect to the rotating surface to be coated, and a distance adjustment mechanism that changes the distance between the spray portion and the surface to be coated, wherein the distance adjustment mechanism drives the base or the spray portion such that the distance between the surface to be coated and the spray portion increases as the spray portion approaches the rotation axis from the outer peripheral side of the surface to be coated.

[0007] According to the above configuration, as the spray portion relatively moves from the outer peripheral side to the inner peripheral side of the surface to be coated and moves away from the surface to be coated as it approaches the rotation axis, the coating range becomes wider and the coating material is dispersed at the rotation axis and its periphery on the surface to be coated. Therefore, it is possible to suppress the rotation axis and its periphery on the surface to be coated from being coated thicker than the outer peripheral side, and to equalize the film thickness.

[0008] In one embodiment, the moving mechanism may drive the base or the spray portion such that the moving speed of the relative movement increases as the spray portion approaches the rotation axis from the outer peripheral side of the surface to be coated.

[0009] According to this configuration, by relatively moving the spray portion such that the moving speed increases as it approaches the rotation axis from the outer peripheral side of the surface to be coated, it is possible to more effectively suppress the rotation axis and its periphery on the surface to be coated from being coated thicker than the outer peripheral side, and to equalize the film thickness.

[0010] In one embodiment, the distance adjustment mechanism includes a swing axis extending in a direction intersecting the rotation axis and a swing mechanism that swings the spray portion around the swing axis, and the swing speed of the swing mechanism may be configured to increase as the spray portion approaches the rotation axis from the outer peripheral edge of the surface to be coated.

[0011] According to this configuration, even if the surface to be coated has not only a flat surface but also irregularities, the swing mechanism can change the angle of the spray portion according to the shape of the surface to be coated, so that the film thickness can be made uniform regardless of the shape of the surface to be coated. Furthermore, since the swing speed increases as the spray portion approaches the rotation axis from the outer peripheral edge of the surface to be coated, it is possible to more effectively suppress the rotation axis and its vicinity on the surface to be coated from being coated thicker than the outer peripheral side, and the film thickness can be made uniform.

[0012] In one embodiment, the spray portion may have a swing center near the surface to be coated.

[0013] According to this configuration, the spray portion can suppress the change in the distance between the surface to be coated and the spray portion due to the change in the swing angle by setting the swing center near the surface to be coated.

[0014] In one embodiment, it is preferable that the spray portion continues to spray the coating material until it reaches from one outer peripheral edge of the surface to be coated to the other outer peripheral edge in the relative movement in a predetermined direction with respect to the surface to be coated.

[0015] According to this configuration, if the spray portion stops spraying in the middle of the surface to be coated, variations in the film thickness will occur. However, by continuing to spray the coating material until it reaches from one outer peripheral edge of the surface to be coated to the other outer peripheral edge, non-uniformity of the film thickness can be prevented.

[0016] In one embodiment, the coating material is sprayed onto a coated surface that is circular in plan view and has a stepped portion in the radial direction. The swing mechanism changes the swing angle of the spray portion based on the angle of the coated surface at the stepped portion, and the change rate of the swing angle with respect to the stepped portion on the inner side in the radial direction may be configured to be faster than the change rate of the swing angle with respect to the stepped portion on the outer side in the radial direction.

[0017] According to this configuration, even if the coated surface has a stepped portion in the radial direction, the film thickness over the entire coated surface can be made uniform by changing the swing angle and the change rate of the swing angle.

[0018] In one embodiment, the spray portion may be arranged so as to be able to pass directly above the rotation axis.

[0019] According to this configuration, by performing the coating while the spray portion passes directly above the rotation axis, it becomes possible to more effectively suppress variations in the film thickness over the entire coated surface.

Advantages of the Invention

[0020] As described above, according to the coating apparatus disclosed herein, it is possible to suppress an increase in the film thickness at the rotation axis portion of the object and its periphery.

Brief Description of the Drawings

[0021]

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Mode for Carrying Out the Invention

[0022] Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. In the following description, terms indicating directions such as left and right, up and down, front and back are used, but these terms indicating directions do not limit the arrangement of the components or the driving direction of the coating device.

[0023] FIG. 1 is a schematic front view of an exemplary coating device 1, FIG. 2 is a schematic plan view, and FIG. 3 is a schematic side view. FIG. 4 is a perspective view showing the main part of the coating device with the spray part removed. X, Y, and Z shown in the figure indicate the X-axis direction, Y-axis direction, and Z-axis direction. In the following embodiments, the X-axis direction indicates the left-right direction, the Y-axis direction indicates the front-back direction, and the Z-axis direction indicates the up-down direction. These directions can be changed according to the embodiment and do not limit the driving direction of the coating device.

[0024] The coating device 1 is a coating device that sprays a coating material onto the coated surface of a rotating object W to form a coating film. The coating device 1 includes a base 2, a spray unit 3, a moving mechanism 4, a distance adjustment mechanism 5, and a drive unit 6.

[0025] The base 2 has a rotating shaft 20 extending in the Z-axis direction. The base 2 fixes the object W with the coated surface facing upward and rotates the object W about the rotating shaft 20. The object W is preferably arranged such that the center of the coated surface is located on a straight line with the rotating shaft 20. The moving mechanism 4 is provided on the base 2. The base 2 is movable in a direction orthogonal to the rotating shaft 20 by the moving mechanism 4. The base 2 is movable in the X-axis direction. The moving mechanism 4 has a sliding rail 41 extending in the X-axis direction. By sliding the base 2 along the sliding rail 41 in the X-axis direction by the moving mechanism 4, the spray unit 3 relatively moves with respect to the rotating coated surface.

[0026] The spray unit 3 is a cylindrical member and is a member that sprays the coating material onto the coated surface. The distance adjustment mechanism 5 is provided on the spray unit 3. The spray unit 3 is supported by a body portion 8 standing adjacent to the sliding rail 41 via the distance adjustment mechanism 5 and is located above the base 2. The spray unit 3 is preferably arranged so as to be able to pass directly above the rotating shaft 20. The spray unit 3 has an injection port downward, and the injection port is directed toward the base 2. The distance adjustment mechanism 5 changes the relative distance between the spray unit 3 and the coated surface. In the present embodiment, the distance adjustment mechanism 5 changes the distance between the spray unit 3 and the coated surface in the Z-axis direction. The distance adjustment mechanism 5 includes a swing shaft 70 and a swing mechanism 7 that swings the spray unit 3 around the swing shaft 70.

[0027] The swing mechanism 7 includes a swing shaft 70, a first swing arm 71, and a second swing arm 72. The swing shaft 70 extends in a direction intersecting the rotation shaft 20. In the present embodiment, the swing shaft 70 is orthogonal to the rotation shaft 20 and the moving direction of the base 2, and extends in the Y-axis direction. The swing shaft 70 is provided on the body portion 8. The swing shaft 70 is provided between the lower end of the spray portion 3 and the upper surface of the base 2. The swing shaft 70, which is the swing center, is preferably provided near the coated surface of the object W. One end of the first swing arm 71 is connected to the swing shaft 70.

[0028] The first swing arm 71 is swingable about the swing shaft 70. The second swing arm 72 is connected to the other end of the first swing arm 71. The second swing arm 72 swings as the first swing arm 71 swings. Further, the second swing arm 72 is slidable in the extending direction of the first swing arm 71. A fixing portion 73 for fixing the spray portion 3 is provided on the second swing arm 72. The spray portion 3 is fixed to the second swing arm 72 via the fixing portion 73. The spray portion 3 slides in the extending direction of the first swing arm 71 together with the second swing arm 72 and swings about the swing shaft 70.

[0029] As shown in FIG. 4, the distance adjustment mechanism 5 includes a first link 51, a second link 52, and connecting shafts 50a, 50b. The connecting shafts 50a, 50b each extend in the Y-axis direction. One end of the first link 51 is connected to the swing shaft 70 and is rotatable about the swing shaft 70. One end of the second link 52 is connected to the other end of the first link 51 via the connecting shaft 50a. The other end of the second link 52 is connected to the second swing arm 72 via the connecting shaft 50b. The second link 52 is rotatable about the connecting shafts 50a, 50b.

[0030] When the first link 51 rotates, the second link 52 is drawn downward or pushed upward along with the movement. The second swing arm 72 connected to the second link 52 slides along the first swing arm 71 as the second link 52 moves. The distance adjustment mechanism 5 converts the rotational motion of the first link 51 into linear motion and slides the second swing arm 72 along the first swing arm 71.

[0031] FIG. 5 is a schematic block diagram of an exemplary coating apparatus. The coating apparatus 1 will be further described with reference to FIGS. 1 and 5. In FIG. 5, solid lines connecting components indicate signal transmission paths, and dashed lines indicate power transmission paths.

[0032] The drive unit 6 includes a first drive unit 61, a second drive unit 62, a third drive unit 63, and a fourth drive unit 64.

[0033] The first drive unit 61 drives the distance adjustment mechanism 5. Specifically, the first drive unit 61 drives the first link 51. A first shaft 61a is connected to the first drive unit 61. The first shaft 61a is rotationally driven by the first drive unit 61, and its power is input to the swing shaft 70 to rotate the first link 51.

[0034] The second drive unit 62 drives the swing mechanism 7. Specifically, the second drive unit 62 drives the first swing arm 71. A second shaft 62a is connected to the second drive unit 62. The second shaft 62a is rotationally driven by the second drive unit 62, and its power is input to the swing shaft 70 to rotate the first swing arm 71.

[0035] The third drive unit 63 rotationally drives the rotary shaft 20. A third shaft 63a is connected to the third drive unit 63. The third shaft 63a is rotationally driven by the third drive unit 63, and its power is input to the rotary shaft 20 to rotate the base 2.

[0036] The fourth drive unit 64 drives the moving mechanism 4. A fourth shaft 64a is connected to the fourth drive unit 64. The fourth shaft 64a is rotationally driven by the fourth drive unit 64, inputs its power to the moving mechanism 4, and slides the base 2 along the sliding rail 41.

[0037] In this embodiment, the distance adjustment mechanism 5 is provided in the spray unit 3 and the moving mechanism 4 is provided in the base 2, but the present invention is not limited to such a configuration. The moving mechanism 4 and the distance adjustment mechanism 5 may be provided in at least one of the base 2 and the spray unit 3. The distance adjustment mechanism 5 only needs to be able to change the relative distance between the spray unit 3 and the surface to be coated, and may be provided in the base 2. The moving mechanism 4 only needs to be able to drive the spray unit 3 to move relative to the surface to be coated, and may be provided in the spray unit 3.

[0038] In this embodiment, the coating apparatus 1 is provided with one set of spray units 3 and bases 2, but the spray units 3 and the bases 2 may be provided with two or more sets. The plurality of bases 2 corresponding to the plurality of spray units 3 may be configured to operate synchronously with each other. For example, in this embodiment, if a plurality of spray units 3 and a plurality of bases 2 are installed in the X-axis direction, the first drive unit 61, the second drive unit 62, the third drive unit 63, and the fourth drive unit 64 can be configured to operate the plurality of spray units 3 and the plurality of bases 2 synchronously.

[0039] The control unit 9 controls the rotary shaft 20, the moving mechanism 4, the distance adjustment mechanism 5, and the swing mechanism 7 by controlling the drive unit 6. The control unit 9 generates a drive signal and outputs the drive signal to the drive unit 6. The control unit 9 controls the drive unit 6, for example, according to a program input in advance based on the shape of the object or according to information obtained by a sensor that detects the shape of the object.

[0040] Under the control of the control unit 9, the distance adjustment mechanism 5 is driven as follows, for example. FIG. 6 is a diagram for explaining the operation of the distance adjustment mechanism, and is a cross-section schematically showing the spray section and the object. In FIG. 6, the surface to be coated of the object W is planar and circular in plan view. With respect to such a surface to be coated, the distance adjustment mechanism 5 drives the spray section 3 so that the distance between the surface to be coated and the spray section 3 becomes longer as the spray section 3 approaches the rotation axis 20 from the outer peripheral edge of the surface to be coated by the movement mechanism 4. In the present embodiment, as the base 2 moves from left to right, the spray section 3 approaches the rotation axis 20 from the outer peripheral edge on the right side of the surface to be coated, passes directly above the rotation axis 20, and reaches the outer peripheral edge on the left side. The spray section 3 is at a greater distance from the surface to be coated when it is located directly above the rotation axis 20 than when it is located at the outer peripheral edge.

[0041] Under the control of the control unit 9, each component is driven as follows, for example. The movement mechanism 4 drives the base 2 so that the movement speed of the spray section 3 increases as it approaches the rotation axis 20 from the outer peripheral edge of the surface to be coated. The swing mechanism 7 drives the spray section 3 so that the swing speed increases as the spray section 3 approaches the rotation axis 20 from the outer peripheral edge of the surface to be coated. Then, the spray section 3 continues to spray the coating material until it reaches from one outer peripheral edge of the surface to be coated to the other outer peripheral edge in the relative movement in a predetermined direction with respect to the surface to be coated.

[0042] By the distance adjustment mechanism 5 and the swing mechanism 7, the spray section 3 is movable in the Z-axis direction and swingable about a swing axis 70 extending in the Y-axis direction. FIGS. 7 to 11 are perspective views showing the main part of the coating apparatus. With reference to FIGS. 7 to 11, the operations of the distance adjustment mechanism 5 and the swing mechanism 7 will be specifically described.

[0043] In FIG. 7, the spray unit 3 faces perpendicularly to the upper surface of the base 2 and is disposed directly above the rotation axis 20. Specifically, the first link 51 and the second link 52 are positioned in a straight line, and the connecting shaft 50a is located above the swing axis 70. At this time, the second swing arm 72 is located above the first swing arm 71, and the spray unit 3 is at the position farthest from the base 2 in the Z-axis direction.

[0044] In FIG. 8, from the state of FIG. 7, the spray unit 3 swings to the right and descends. Specifically, the first swing arm 71 and the second swing arm 72 swing to the right around the swing axis 70. Further, the first link 51 rotates slightly to the left and the first link 51 and the second link 52 are refracted, so that the second swing arm 72 is drawn in the direction approaching the swing axis 70. The spray unit 3 is directed to the left side of the rotation axis 20.

[0045] In FIG. 9, from the state of FIG. 7, the spray unit 3 descends. Specifically, the first link 51 rotates to the left and becomes parallel to the X-axis direction, and the first link 51 and the second link 52 are refracted, so that the second swing arm 72 is drawn in the direction approaching the swing axis 70.

[0046] In FIG. 10, from the state of FIG. 9, the spray unit 3 descends further. Specifically, the first link 51 rotates 180° from the state of FIG. 7 and becomes parallel to the Z-axis direction. The connecting shaft 50a is located below the swing axis 70, and the first link 51 and the second link 52 overlap in a straight line, so that the second swing arm 72 is further drawn in the direction approaching the swing axis 70.

[0047] In FIG. 11, from the state of FIG. 10, the spray unit 3 swings to the left. Specifically, the first swing arm 71 and the second swing arm 72 swing to the left around the swing axis 70 while maintaining the arrangement of the first link 51 and the second link 52.

[0048] The coating device 1 configured as described above suppresses the rotation axis on the surface to be coated and its periphery from being coated thicker than the outer peripheral side, and can equalize the film thickness.

[0049] Even when there are irregularities on the coated surface of the object W, the coating device 1 can suppress the rotation axis and its periphery on the coated surface from being coated thicker than the outer peripheral side, and can equalize the film thickness. FIGS. 12, 14, and 16 are perspective views showing the main parts of the object and the coating device, and show how the coating material is applied to the coated surface having a stepped portion. FIGS. 13, 15, and 17 are schematic cross-sectional views showing the spray portion and the object. Based on FIGS. 12 to 17, the angle between the stepped portion of the coated surface and the spray portion 3 will be described.

[0050] The coated surface of the object shown in FIGS. 12 to 17 is circular in plan view and has a stepped portion in the radial direction. Specifically, the coated surface has a plurality of stepped portions formed with the inner peripheral side being lower than the outer peripheral side, and has a curved portion that bulges upward at the central portion located on or near the rotation axis 20.

[0051] In FIGS. 12 to 17, the base 2 moves from the left side to the right side of the spray portion 3. As shown in FIGS. 12 and 13, the spray portion 3 starts coating from the right end portion of the object W. The coated surface at the right end portion of the object W is a horizontal plane. The spray portion 3 is directed in a direction substantially perpendicular to the coated surface at the right end portion.

[0052] As shown in FIGS. 14 and 15, when the base 2 moves further to the right, the spray portion 3 is directed toward the stepped portion. At this time, the swing mechanism 7 changes the swing angle of the spray portion 3 based on the step of the coated surface, and drives the spray portion 3 to be directed in a direction substantially perpendicular to the coated surface at the stepped portion.

[0053] As shown in FIGS. 16 and 17, when the base 2 moves further to the right, the spray unit 3 points to a curved portion that bulges upward at approximately the central portion. At this time, the swing mechanism 7 changes the swing angle of the spray unit 3 based on the step of the surface to be coated, and drives the spray unit 3 to point in a substantially vertical direction with respect to the surface to be coated at the step portion. Further, the swing mechanism 7 drives the spray unit 3 such that the change speed of the swing angle with respect to the step portion on the inner side in the radial direction is faster than the change speed of the swing angle with respect to the step portion on the outer side in the radial direction.

[0054] The foregoing embodiments are merely illustrative and should not be construed as limiting the scope of the present disclosure. The scope of the present disclosure is defined by the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present disclosure.

Industrial Applicability

[0055] The technology disclosed herein is suitably used in various manufacturing sites as a coating apparatus for spraying a coating material onto a rotating object.

Explanation of Reference Numerals

[0056] 1 Coating apparatus 2 Base 3 Spray unit 4 Moving mechanism 5 Distance adjustment mechanism 6 Driving unit 7 Swing mechanism 8 Body 9 Control unit 20 Rotation axis 50a Connecting shaft 50b Connecting shaft 51 First link 52 Second link 70 Swing axis 71 First swing arm 72 Second swing arm W Object

Claims

1. A coating apparatus for forming a coating film by spraying a coating material onto a coated surface of a rotating object, comprising: a base that fixes the object with the coated surface directed upward and rotates the object about a rotation axis; a spray section directed toward the base; a moving mechanism provided on at least one of the base and the spray section, for relatively moving the spray section with respect to the rotating coated surface, and a distance adjustment mechanism for changing the distance between the spray section and the coated surface; wherein the distance adjustment mechanism drives the base or the spray section such that the distance between the coated surface and the spray section increases as the spray section approaches the rotation axis from the outer peripheral side of the coated surface. The coating apparatus is characterized by the above.

2. The coating apparatus according to claim 1, wherein the moving mechanism drives the base or the spray section such that the relative movement speed increases as the spray section approaches the rotation axis from the outer peripheral side of the coated surface. The coating apparatus is characterized by the above.

3. The coating apparatus according to claim 2, wherein the distance adjustment mechanism includes a swing axis extending in a direction intersecting the rotation axis, and a swing mechanism for swinging the spray section around the swing axis, and the swing speed of the swing mechanism increases as the spray section approaches the rotation axis from the outer peripheral side of the coated surface. The coating apparatus is characterized by the above.

4. The coating apparatus according to claim 3, wherein the spray section has a swing center near the coated surface. The coating apparatus is characterized by the above.

5. The coating apparatus according to claim 1, wherein the spray section continues to spray the coating material until it reaches from one outer peripheral edge of the coated surface to the other outer peripheral edge in a relative movement in a predetermined direction with respect to the coated surface. The coating apparatus is characterized by the above.

6. The coating apparatus according to claim 3 or 4, for spraying a coating material onto a coated surface that is circular in plan view and has a stepped portion in the radial direction, wherein the swing mechanism changes the swing angle of the spray section based on the angle of the coated surface at the stepped portion, and the change speed of the swing angle with respect to the stepped portion on the inner side in the radial direction is faster than the change speed of the swing angle with respect to the stepped portion on the outer side in the radial direction. The coating apparatus is characterized by the above.

7. The coating apparatus according to claim 1, wherein the spray section is arranged so as to be able to pass directly above the rotation axis. The coating apparatus is characterized by the above.

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