Coating apparatus, and coating method

Abstract

To enable improving coating quality.SOLUTION: A coating apparatus coats a coating area of an object to be coated having a convex curved surface. The coating apparatus includes a head, an arm, and a controller. The head has a nozzle surface. The arm holds the head. The controller controls movement of the head via the arm. The controller moves the head in a first direction along an end part of the coating area in a posture in which a gap between a nozzle surface which is located on an end part side of the coating area and an object to be coated is smaller than a gap between the nozzle surface located on a center side of the coating area and the object to be coated.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosed embodiments relate to a coating device, a coating film, and a coating method. [Background technology]

[0002] 2. Description of the Related Art A coating device using an inkjet system is known. Such an inkjet coating device is equipped with a head for discharging coating materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-121944 [Patent Document 2] Japanese Patent Application Publication No. 7-108212 Summary of the Invention

[0004] A coating device according to one aspect of the embodiment coats a coating area of ​​a workpiece having a convex curved surface. The coating device includes a head, an arm, and a control unit. The head has a nozzle surface. The arm holds the head. The control unit controls the movement of the head via the arm. The control unit moves the head in a first direction along the edge of the coating area in a position where the distance between the nozzle surface located on the edge side of the coating area and the workpiece is smaller than the distance between the nozzle surface located on the center side of the coating area and the workpiece. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is an explanatory diagram of a coating device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an example of a coated object. [Figure 3] FIG. 3 is an explanatory diagram showing an example of the arrangement of heads provided in the coating device according to the first embodiment. [Figure 4]FIG. 4 is an explanatory diagram showing an example of droplets ejected from the coating device according to the second embodiment. [Figure 5A] FIG. 5A is an explanatory diagram for comparing coating material discharging techniques. [Figure 5B] FIG. 5B is an explanatory diagram for comparing coating material discharging techniques. [Figure 6] FIG. 6 is an explanatory diagram showing an example of droplets ejected from a coating device according to a third embodiment. [Figure 7] FIG. 7 is a partially enlarged view of FIG. [Figure 8] FIG. 8 is an explanatory diagram showing an example of droplets ejected from a coating device according to a fourth embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing an example of a coated body according to an embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a head according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, embodiments of a coating apparatus, a coating film, and a coating method disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

[0007] <Configuration of painting equipment> First, an overview of a coating apparatus according to an embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram of a coating apparatus according to an embodiment. For ease of understanding, Fig. 1 illustrates a three-dimensional Cartesian coordinate system including a Z axis, with the vertical upward direction as the positive direction and the vertical downward direction as the negative direction. This Cartesian coordinate system may also be illustrated in other drawings used in the following description. Furthermore, the same reference numerals are used to designate components similar to those of the coating apparatus 1 shown in Fig. 1, and their description will be omitted or simplified.

[0008] As shown in FIG. 1, the coating device 1 includes a head 10, a robot 20, and a control device 40.

[0009] The head 10 is fixed to the robot 20. The head 10 moves in accordance with the operation of the robot 20, which is controlled by the control device 40. The head 10 may be, for example, a valve-type, piezo-type, or thermal-type inkjet head. Using a piezo-type or thermal-type inkjet head as the head 10 makes it easier to achieve high resolution.

[0010] The head 10 coats the object 30 by ejecting the coating material from a plurality of ejection holes 11 located on the nozzle surface 12 and causing the material to land on the surface of the object 30 facing the nozzle surface 12 .

[0011] The head 10 is supplied with coating material from a tank (not shown). The head 10 ejects the coating material supplied from the tank. The coating material is a mixture containing volatile and non-volatile components and has fluidity. The tank may be a reservoir (not shown) housed in the head 10.

[0012] Volatile components include, for example, water, organic solvents, and alcohols, and adjust the physical properties of the coating material, such as viscosity and surface tension. Non-volatile components include, for example, pigments, resin materials, and additives. Pigments include one or more color pigments used depending on the desired coating color. Resin materials adhere to the object 30 to form a film. Additives are functional materials added for purposes such as weather resistance.

[0013] The coating material supplied to the discharge holes 11 is prepared by mixing a plurality of color pigments or coating materials in a predetermined ratio so as to produce a desired coating color.

[0014] The robot 20 holds the head 10. The robot 20 is, for example, a six-axis articulated robot. The robot 20 may be, for example, a vertical articulated robot or a horizontal articulated robot. The robot 20 has a plurality of arms 21, and the head 10 is fixed to the tip of each arm 21. The robot 20 is fixed to a floor, wall, ceiling, or the like. Note that there is no limit to the degree of freedom of the arms 21 of the robot 20, as long as the held head 10 can be moved appropriately.

[0015] The control device 40 controls the coating device 1. The control device 40 includes a control unit 41 that controls the coating device 1, and a storage unit 45. The control unit 41 includes a discharge control unit 42 and an operation control unit 43.

[0016] The control unit 41 includes, for example, a computer having a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), hard disk drive (HDD), input / output ports, and various other circuits. The CPU of such a computer functions as the control unit 41 by, for example, reading and executing a program stored in the ROM. The control unit 41 may also be configured with hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0017] The discharge control unit 42 controls the head 10 based on the setting information stored in the memory unit 45, causing the coating material to be discharged from the multiple discharge holes 11 toward the workpiece 30. The operation control unit 43 controls the operation of the multiple arms 21 based on the setting information stored in the memory unit 45, and controls the movement of the head 10 via the arms 21. The distance between the head 10 and the workpiece 30 is maintained at, for example, about 0.5 to 14 mm. The detailed movement of the head 10, including the discharge of the coating material, will be described later.

[0018] The storage unit 45 corresponds to, for example, a ROM and a HDD. The ROM and HDD can store setting information for various controls in the control device 40. The storage unit 45 stores information related to the control of the discharge of coating material by the head 10. The storage unit 45 also stores information related to the operation control of the multiple arms 21. Note that the storage unit 45 may store data input by a user through a teaching operation using a terminal device (not shown) as teaching data for operating the robot 20. The control unit 41 may also acquire setting information via another computer or portable recording medium connected via a wired or wireless network.

[0019] The object 30 to be coated is, for example, a vehicle body. The object 30 to be coated is placed on a transport device (not shown) and is transported in and out. The coating apparatus 1 according to the embodiment coats the object 30 to be coated while the transport device is stopped. Note that the coating apparatus 1 may be one that coats the object 30 to be coated that is repeatedly transported and stopped, or one that coats the object 30 in parallel with its transportation.

[0020] FIG. 2 is a cross-sectional view showing an example of a coated object. The object 30 shown in FIG. 2 includes a substrate 31, a primer layer 32, and a first paint layer 33. The substrate 31 is, for example, a steel plate processed into a predetermined shape, and is subjected to electrodeposition treatment as needed to provide rust resistance. The primer layer 32 is provided, for example, to provide weather resistance, color development, and peel resistance. The first paint layer 33 is, for example, a base layer that has smoothness and weather resistance and imparts a desired paint color. The surface of the first paint layer 33 becomes the surface 30a to be coated using the coating apparatus 1 according to this embodiment.

[0021] A second paint layer 34 is positioned on the first paint layer 33, which is the surface 30a to be painted. The second paint layer 34 is positioned so as to cover a portion of the first paint layer 33 with a paint material having a different paint color from that of the first paint layer 33. As a result, the object 30 becomes a painted body 38 that is painted in a so-called two-tone color, with an edge 37 of the second paint layer 34 as the boundary between an area 36 where the second paint layer 34 is located and an area 35 where the second paint layer 34 is not located and the first paint layer 33 is exposed.

[0022] In the example shown in Figure 2, the painting device 1 is described as positioning the second paint layer 34 on the surface to be painted 30a on the first paint layer 33, but this is not limited to this, and the painting device 1 may also be applied when, for example, positioning the first paint layer 33 on the painting surface 32a on the primer layer 32.

[0023] The coated body 38 is not limited to the example shown in Fig. 2. For example, a coating layer (not shown) may be located on the surface of the regions 35, 36. Also, the coated body 38 may have only the first coated layer 33 without the second coated layer 34, or the second coated layer 34 may be located on the entire surface of the first coated layer 33. Furthermore, the coated object 30 or the coated body 38 may further have one or more layers (not shown).

[0024] First Embodiment FIG. 3 is an explanatory diagram showing an example of the arrangement of heads in the coating apparatus according to the first embodiment. FIG. 3 corresponds to a cross-sectional view of the head 10 and the workpiece 30 facing the nozzle surface 12 of the head 10, as viewed from the negative Y-axis direction. For ease of explanation, the workpiece 30 has an arch-shaped cross section in which the central portion of the region 36 in the X-axis direction protrudes toward the positive Z-axis direction, and the surface 30a to be coated includes a convex curved surface of the workpiece 30. The workpiece 30 may be, for example, a hood, roof, or pillar of the exterior of a vehicle. Alternatively, the workpiece 30 may be, for example, an instrument panel, glove box, or center console of the interior of a vehicle.

[0025] In addition, in each of the embodiments described below, an example will be described in which the head 10 ejects a coating material that positions the second coating layer 34 in the region 36. The coating devices 1 according to each of the embodiments described below have a common configuration except for the operation of the head 10. For this reason, configurations other than the head 10, such as the robot 20 and the control device 40, are not shown in the drawings.

[0026] The head 10 shown in Fig. 3 moves in the Y-axis direction as a first direction while facing the object 30 to be coated. 2 / min more than 5m 2 To achieve such an area coating speed, when the length of the printing area of ​​the head 10 is 100 mm, the moving speed of the head 10 in the X-axis direction should be, for example, 1.67×10 2 mm / s or more 41.67×10 2 It is sufficient to move the head in the X-axis direction at a predetermined speed of mm / s or less. Note that this example uses one head 10, but two or more heads 10 may also be used.

[0027] The resolution of the head 10 can be, for example, 150 dpi (dots per inch) or more. More preferably, the resolution of the head 10 is 300 dpi or more. When the resolution of the head 10 is 150 dpi or more, the leveling ability is improved, and the quality of the coating film is improved. However, the resolution of the head 10 does not necessarily have to be 150 dpi or more.

[0028] In addition, in the end region 36a located on the end 37a side of the region 36 as the painting region, the head 10 faces the surface 30a to be painted in an inclined position so that the distance d1 between the nozzle surface 12 located on the end 37a side and the object 30 to be painted is smaller than the distance d2 between the nozzle surface 12 located on the central side of the region 36 and the object 30 to be painted.

[0029] By tilting the head 10 relative to the surface 30a, the distance between the nozzle face 12 and the edge 37a of the region 36 is reduced. This results in a sharper boundary of the second coating layer 34, which will be positioned on the edge 37a, and a more attractive appearance. Therefore, the coating apparatus 1 according to this embodiment can improve coating quality.

[0030] Here, the distance d1 can be set to, for example, about 0.5 to 14 mm, and the distance d2 can be set to, for example, about 2.0 to 30 mm, but the distances d1 and d2 can be changed depending on the size of the head 10 and the curvature of the surface 30a to be coated.

[0031] Furthermore, in the central region 36b located between the end regions 36a of the region 36, the distance d3 between the nozzle surface 12 and the workpiece 30 can be set to, for example, d1 or more and less than d2. By specifying the distance d3 in this manner, it becomes easier to stabilize the thickness of the second coating layer 34, thereby improving the coating quality.

[0032] Furthermore, the length L1 of the edge region 36a along the X-axis direction can be set to approximately 0.1L, for example, 0.05L or more and 0.15L or less, relative to the total length L of the region 36 along the X-axis direction. The edge region 36a is also inclined more than the central region 36b. This makes the boundary between the edge region 36a and the central region 36b less noticeable, improving the coating quality. The boundary between the edge region 36a and the non-coated region is also clearly defined, improving the appearance. In this embodiment, the curvature of the surface 30a to be coated is illustrated as being greater in the edge region 36a than in the central region 36b, but this is not limited to this. For example, the curvature of the edge region 36a may be smaller than that of the central region 36b, or the curvature may be constant throughout the entire surface 30a to be coated.

[0033] <Second embodiment> Fig. 4 is an explanatory diagram showing an example of ejected droplets according to the second embodiment. As shown in Fig. 4, in the region 36 as the coating region, the size of the ejected droplets of the coating material ejected from the nozzle surface 12 differs between an end region 36c located on the end 37a side and a central region 36d located between the end regions 36c. Specifically, the ejected droplets 16a located in the end region 36c are larger than the ejected droplets 16b located in the central region 36d.

[0034] By making the droplets 16a larger than the droplets 16b in this way, the contrast of the second paint layer 34 located on the edge 37a, for example, is enhanced, improving the appearance and thereby improving the paint quality.

[0035] Here, the technique for discharging the coating material onto the surface 30a to be coated in the edge region 36c will be described with reference to Figures 5A and 5B. Figures 5A and 5B are explanatory diagrams comparing the techniques for discharging the coating material.

[0036] In the example shown in Fig. 5A, droplets 16a of a size corresponding to the coating material 16a1 as the discharged liquid discharged from the nozzle surface 12 of the head 10 are positioned on the surface 30a to be coated. In other words, the amount of the coating material 16a1 discharged corresponds to the size of the droplets 16a. The head 10 shown in Fig. 5A may be prepared separately from the head 10 that discharges the droplets 16b, for example. Therefore, the coating apparatus 1 according to the embodiment can include multiple heads 10 with droplets 16 of different sizes.

[0037] 5B differs from the example shown in FIG. 5A in that the size of the coating material 16a2 ejected from the nozzle surface 12 of the head 10 is smaller than the ejected droplets 16a. By controlling the ejection interval of the coating material 16a2 and allowing multiple droplets of the coating material 16a2 to coalesce before reaching the surface 30a, ejected droplets 16a larger than the coating material 16a2 can be positioned on the surface 30a. Therefore, in the coating device 1 according to the embodiment, the ejection control unit 42 controls the ejection interval from the nozzle surface 12, thereby varying the amount of coating material 16a2 ejected from the head 10 as the ejected liquid per unit area of ​​the surface 30a. This allows the edge region 36c and the central region 36d to be painted using a single type of head 10.

[0038] Returning to FIG. 4, the length L2 of the edge region 36c along the X-axis direction can be set to approximately 0.1L, for example, 0.05L or more and 0.15L or less, relative to the total length L of the region 36 along the X-axis direction. The edge region 36c is also more inclined than the central region 36d. This makes the boundary between the edge region 36c and the central region 36d less noticeable, improving the coating quality. Furthermore, the boundary between the edge region 36c and the non-coated region is more distinct, improving the appearance.

[0039] <Third embodiment> 6 is an explanatory diagram showing an example of ejected droplets according to the third embodiment. As shown in Fig. 6, in the region 36 serving as the coating region, the ejection density of the coating material ejected from the nozzle surface 12 differs between an edge region 36e located on the edge 37a side and a central region 36f located between the edge regions 36e. Specifically, the ejection density of the ejected droplets 16 located in the edge region 36e is greater than the ejection density of the ejected droplets 16 located in the central region 36f.

[0040] By making the ejection density of the droplets 16 located in the edge region 36e greater than that of the droplets 16 located in the central region 36f, the contrast of the second coating layer 34 located on the edge 37a, for example, becomes stronger, improving the appearance, and thus improving the coating quality.

[0041] Here, the length L3 of the edge region 36e along the X-axis direction can be set to approximately 0.1L, for example, 0.05L or more and 0.15L or less, relative to the total length L of the region 36 along the X-axis direction. The edge region 36e is also inclined more than the central region 36f. This makes the boundary between the edge region 36e and the central region 36f less noticeable, improving the coating quality. Furthermore, the boundary between the edge region 36e and the non-coated region is more distinct, improving the appearance.

[0042] As described above, the coating apparatus 1 according to this embodiment moves the head 10 in the Y-axis direction as a first direction, then displaces the head 10 in the X-axis direction according to the dimension of the nozzle surface 12 in the X-axis direction, and moves it again in the Y-axis direction. This point will be described with reference to FIG. 7.

[0043] Fig. 7 is a partially enlarged view of Fig. 6. The region 80 shown in Fig. 7 corresponds to an enlarged view of the region 80 in the central region 36f shown in Fig. 6.

[0044] In Figure 7, the ejected droplet 16 ejected onto area 80 on the surface 30a to be coated by the head 10 located at position 10-a in the X-axis direction moving along the Y-axis direction is shown as ejected droplet 16-A, and the ejected droplet 16 ejected onto area 80 on the surface 30a to be coated from the head 10 located at position 10-b is shown as ejected droplet 16-B.

[0045] At this time, in portion 81, of the multiple ejection holes 11 opening in the nozzle surface 12, the ejection hole 11 located at the end on the positive side of the X-axis of the head 10 located at position 10-A and the ejection hole 11 located at the end on the negative side of the X-axis of the head 10 located at position 10-B overlap in a planar view. By overlapping some of the ejection holes 11 in a planar view in this way, it is possible to reduce paint voids and smears, but there is also the concern of uneven coating.

[0046] Therefore, as shown in FIG. 7, the discharge of coating material from the nozzle surface 12 is controlled so that the discharge density in a portion 81, which is an overlapping portion of the discharge holes 11, is smaller than the discharge density outside the portion 81. This reduces the occurrence of coating unevenness in the portion 81, for example, thereby improving coating quality. Note that in the example shown in FIG. 7, the discharge densities of the discharged droplets 16-A and 16-B in the portion 81 are reduced to the same extent, but this is not limiting, and the discharge densities of the discharged droplets 16-A and 16-B may be different. Furthermore, it is sufficient for each head 10 to discharge the droplets so that the discharge density in the portion 81 is smaller than the discharge density outside the portion 81. For example, it is acceptable for the discharge density in the portion 81 to be 60% of the discharge density outside the portion 81 (i.e., the discharge density in the portion 81 is 120%).

[0047] <Fourth embodiment> 8 is an explanatory diagram showing an example of ejected droplets according to the fourth embodiment. As shown in Fig. 8, in the region 36 as a coating region, the size of the ejected droplets of the coating material ejected from the nozzle surface 12 differs between an end region 36g located on the end 37a side and a central region 36h located between the end regions 36g, which is the same as the third embodiment. In this embodiment, the ejected droplets 16a located in the end region 36g are smaller than the ejected droplets 16b located in the central region 36h.

[0048] By making the droplets 16a smaller than the droplets 16b, the droplets 16b located on the edge 37a, which has a larger curvature than the central region 36h, are less likely to drip, improving the coating quality. Also, the boundary between the edge region 36g and the non-coated region is more clearly defined, improving the appearance.

[0049] Here, the length L4 of the edge region 36g along the X-axis direction can be set to approximately 0.1L, for example, 0.05L or more and 0.15L or less, relative to the total length L of the region 36 along the X-axis direction. The edge region 36g is also inclined more than the central region 36h. This makes the boundary between the edge region 36g and the central region 36h less noticeable, improving the coating quality. Furthermore, the boundary between the edge region 36g and the non-coated region is clearer, improving the appearance.

[0050] <Paint film> Next, a coating film according to an embodiment will be described. Fig. 9 is a cross-sectional view showing an example of a coated body according to an embodiment.

[0051] As shown in FIG. 9, the second paint layer 34 (paint film) has a thick film portion 34a in an edge region 36j located on the edge 37a side of the painted region 36. The thick film portion 34a extends in the Y-axis direction (first direction) along the edge 37a. The thickness d11 of the thick film portion 34a is greater than the thickness d12 of the second paint layer 34 in a central region 36k located between the edge regions 36j. This enhances the contrast of the edge 37 of the second paint layer 34, improving its appearance. This improves the paint quality.

[0052] The second coating layer 34 also has a recess 34c adjacent to the thick portion 34a along the Y-axis direction. This relieves stress caused by the presence of the thick portion 34a and reduces peeling of the second coating layer 34 from the coating surface 30a. The recess 34c refers to the inflection point where the thick portion 34a intersects with the central region 36k in cross-sectional view, and does not need to be thinner than the thickness d12 of the second coating layer 34.

[0053] Here, the thickness d11 can be set to, for example, about 7 μm to 70 μm, and the thickness d12 can be set to, for example, about 5 μm to 50 μm.

[0054] The second paint layer 34 also has multiple protrusions 34b located along the Y-axis in a central region 36k, which is the central portion of the paint region. If the thickness d12 of the second paint layer 34 at the protrusions 34b is smaller than the thickness d11 of the thick film portion 34a, the occurrence of uneven paintwork at the protrusions 34b, for example, is reduced, thereby improving paint quality. On the other hand, if the thickness d12 of the second paint layer 34 at the protrusions 34b is larger than the thickness d11 of the thick film portion 34a, for example, the contrast of the edge 37 is enhanced, improving the appearance. This improves paint quality. In a painted body 38 in which a coating layer 39 is positioned on the second paint layer 34, color unevenness caused by the protrusions 34b, for example, is less noticeable, further improving paint quality.

[0055] <Modification of the first embodiment> In the above-described embodiments, the workpiece 30 has been described as having an arch-shaped curved surface, but this is not limiting and may be, for example, a dome-shaped curved surface. Furthermore, the surface 30a of the workpiece 30 may be flat or may be produced by drawing. Figure 10 is an explanatory diagram showing an example of the arrangement of the heads according to a modification of the first embodiment.

[0056] The object 30 shown in FIG. 10 differs from the surface 30a to be coated by the coating device 1 according to the first embodiment in that the surface 30a to be coated is flat.

[0057] In addition, in the end region 36m located on the end 37a side of the region 36 as the painting region, the head 10 faces the surface 30a to be painted in an inclined position so that the distance d21 between the nozzle surface 12 located on the end 37a side and the object 30 to be painted is smaller than the distance d22 between the nozzle surface 12 located on the central side of the region 36 and the object 30 to be painted.

[0058] By tilting the head 10 relative to the surface 30a, the distance between the nozzle face 12 and the edge 37a is reduced. This results in a sharper boundary of the second coating layer 34, which will be positioned on the edge 37a, and a more attractive appearance. This improves the quality of the coating.

[0059] Here, the distance d21 can be set to, for example, about 0.5 to 20 mm, and the distance d22 can be set to, for example, about 2 to 30 mm.

[0060] Furthermore, in the central region 36n of the region 36, which is located between the end regions 36m, the distance d23 between the nozzle surface 12 and the workpiece 30 can be, for example, equal to or greater than d21 and less than d22. Specifying the distance d23 in this manner makes it easier to stabilize the thickness of the second coating layer 34, thereby improving coating quality. In the example shown in FIG. 10, the distance 24 between the center 14 of the head 10 and the surface 30a to be coated is constantly constant throughout the entire region 36. This further stabilizes the thickness of the second coating layer 34, thereby improving coating quality.

[0061] The length L5 of the end region 36m along the X-axis direction can be set to about 0.1L, for example, 0.05L or more and 0.15L or less, relative to the total length L of the region 36 along the X-axis direction.

[0062] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiments, the coating device 1 is described as having one head 10 that dispenses a single color coating material, but the coating device 1 may be provided with robots 20 that hold heads 10 that dispense coating materials of basic colors such as magenta (M), yellow (Y), cyan (C), and black (K).

[0063] In the above embodiment, the surface 30a to be coated is painted from the positive side of the Z axis, but the present invention is not limited to this. For example, the surface 30a may be painted from the negative side of the Z axis, or the surface 30a may be a side surface located along the YZ plane or the ZX plane. Furthermore, the coating device 1 may be used when painting a surface 30a to be coated that is oblique to the Z axis.

[0064] Furthermore, two or more of the first to fourth embodiments may be combined. In such a case, the lengths L1 to L4 may be the same or different from each other.

[0065] As described above, the coating apparatus 1 according to the embodiment coats a workpiece 30 having a convex curved surface. The coating apparatus 1 includes a head 10, an arm 21, and a control unit 41. The head 10 has a nozzle surface 12. The arm 21 holds the head 10. The control unit 41 controls the movement of the head 10 via the arm 21. The control unit 41 moves the head 10 in a first direction along the end 37a of the coating area while positioning the head 10 so that the distance d1 between the nozzle surface 12 located on the end 37a side of the coating area of ​​the workpiece 30 and the workpiece 30 is smaller than the distance d2 between the nozzle surface 12 located on the center side of the coating area and the workpiece 30. This improves coating quality.

[0066] Furthermore, the coating apparatus 1 according to the embodiment coats a coating object 30 having a convex curved surface. The coating apparatus 1 includes a head 10, an arm 21, and a control unit 41. The head 10 has a nozzle surface 12. The arm 21 holds the head 10. The control unit 41 controls the movement of the head 10 via the arm 21. The head 10 discharges coating material with droplets of different sizes between the edge of the coating area and the center of the coating area. This improves coating quality.

[0067] Furthermore, the coating apparatus 1 according to the embodiment coats a workpiece 30 having a convex curved surface. The coating apparatus 1 includes a head 10 and a control unit 41. The head 10 has a nozzle surface 12. The control unit 41 controls the discharge of coating material from the nozzle surface 12. The discharge density of the coating material at the edge of the coating area of ​​the workpiece 30 is greater than the discharge density at the center of the coating area. This improves the coating quality.

[0068] Furthermore, the coating film according to the embodiment has thick film portions 34a extending in the first direction along the edges of the coating area of ​​the coating object 30. This can improve the coating quality.

[0069] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0070] 1. Painting equipment 10 heads 11 Discharge hole 12 Nozzle surface 16 Discharge droplet 20. Robot 21 Arm 30 Object to be painted 30a Surface to be painted 40 Control device 41 Control Unit 42 Discharge control section 43 Motion control section 45 Storage section

Claims

1. A coating device for coating a coating area of ​​an object having a convex curved surface, a head having a nozzle surface; an arm for holding the head; a control unit that controls the movement of the head via the arm; Equipped with The control unit The head is moved in a first direction along the edge of the coating area in a posture in which a distance between the nozzle surface located on the edge side of the coating area and the object to be coated is smaller than a distance between the nozzle surface located on the center side of the coating area and the object to be coated. Painting equipment.

2. A coating device for coating a coating area of ​​an object having a convex curved surface, a head having a nozzle surface; an arm for holding the head; a control unit that controls the discharge of coating material from the nozzle surface; Equipped with The head The size of the droplets of the coating material is varied between the edge of the coating area and the center of the coating area. Painting equipment.

3. The droplets discharged to the central portion are smaller than the droplets discharged to the end portions. The coating device according to claim 2.

4. The droplets discharged to the end portions are smaller than the droplets discharged to the center portion. The coating device according to claim 2.

5. The head includes a plurality of heads each having a different size of ejected droplets. The coating device according to any one of claims 2 to 4.

6. A coating device for coating a coating area of ​​an object having a convex curved surface, a head having a nozzle surface; an arm for holding the head; a control unit that controls the discharge of coating material from the nozzle surface; Equipped with The head The size of the droplets of the coating material is varied depending on the curvature of the coating area. Painting equipment.

7. A coating device for coating a coating area of ​​an object having a convex curved surface, a head having a nozzle surface; a control unit that controls the discharge of coating material from the nozzle surface; Equipped with The coating material is sprayed at a density greater at the edge of the coating area than at the center of the coating area. Painting equipment.

8. an arm that holds the head and operates the head under the control of the control unit; the control unit moves the head so that a plurality of ejection holes opening on the nozzle surface partially overlap each other in a plan view; The discharge density at the overlapping portion of the discharge holes is smaller than the discharge density at the other portion than the overlapping portion. The coating device according to claim 7.

9. The resolution of the head is 150 dpi or more. The coating device according to any one of claims 1 to 8.

10. A coating film applied to a coating area of ​​an object having a convex curved surface, a thick film portion extending in a first direction along an edge of the coating area; Paint film.

11. a recess adjacent to the thick film portion along the first direction; The coating film according to claim 10.

12. a convex portion located in the first direction in a central portion of the coating area; The thickness of the thick film portion is greater than the thickness of the protrusion portion. The coating film according to claim 10 or 11.

13. a convex portion located in a central portion of the coating area and aligned with the thick film portion; The thickness of the thick film portion is smaller than the thickness of the protrusion portion. The coating film according to claim 10 or 11.

14. A coating method for coating a coating area of ​​an object having a convex curved surface, comprising: a step of positioning the head so that a distance between the nozzle surface of the head positioned at the end of the coating area and the object to be coated is smaller than a distance between the nozzle surface positioned at the center of the coating area and the object to be coated; moving the head in a direction along the edge of the coating area; A painting method including:

15. a step of discharging the coating material from the nozzle surface so that the amount of the discharged liquid discharged toward the edge of the coating area is less than the amount of the discharged liquid discharged toward the center. The coating method of claim 14, comprising:

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