Coating device and coating method

Abstract

Improves coating quality. [Solution] The coating device includes a head, an arm, and a control unit. The head has a nozzle face. The arm holds the head. The control unit controls movement of the head via the arm. With the nozzle face facing the workpiece, the control unit moves the head in a first direction along the nozzle face, vibrates the head in a second direction intersecting the first direction, and / or rotates and swings the head along the nozzle face.

Description

[Technical field]

[0001] The disclosed embodiments relate to a painting apparatus and a painting method. [Background technology]

[0002] 2. Description of the Related Art There are known coating devices that use an inkjet system. Such inkjet coating devices are equipped with a head for ejecting coating materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-202781 A [Patent Document 2] Special Publication No. 2012-506305 Summary of the Invention

[0004] A coating device according to one aspect of the embodiment includes a head, an arm, and a control unit. The head has a nozzle surface. The arm holds the head. The control unit controls movement of the head via the arm. With the nozzle surface facing an object to be coated, the control unit moves the head in a first direction along the nozzle surface, vibrates the head in a second direction intersecting the first direction, and / or rotates and swings the head along the nozzle surface. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is an explanatory diagram of a coating device according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of a coated object. [Diagram 3] FIG. 3 is a diagram showing an example of a head included in the coating device according to the first embodiment. [Figure 4A] FIG. 4A is an enlarged view for comparing the arrangement of droplets discharged onto a workpiece. [Figure 4B] FIG. 4B is an enlarged view for comparing the arrangement of droplets discharged onto the workpiece. [Figure 4C] FIG. 4C is an enlarged view for comparing the arrangement of droplets discharged onto the workpiece. [Diagram 5] FIG. 5 is a diagram showing an example of a head included in a coating device according to a second embodiment. [Figure 6] FIG. 6 is a diagram showing an arrangement of ejection holes in a head of a coating device according to an embodiment. [Figure 7] FIG. 7 is a diagram showing an example of a head included in a coating device according to a modified example of the second embodiment. [Figure 8A] FIG. 8A is an enlarged view comparing droplets discharged onto a workpiece. [Figure 8B] FIG. 8B is an enlarged view comparing droplets discharged onto a workpiece. [Figure 8C] FIG. 8C is an enlarged view comparing droplets discharged onto a workpiece. [Figure 9] FIG. 9 is a diagram showing an example of a head included in a coating device according to a third embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a head included in a coating device according to a fourth embodiment. [Figure 11] FIG. 11 is a diagram showing an example of a head included in a coating device according to a fifth embodiment. [Figure 12] FIG. 12 is a diagram showing an example of a head included in a coating device according to a fifth embodiment. [Figure 13] FIG. 13 is a diagram showing an example of a head included in a coating device according to a sixth embodiment. [Figure 14] FIG. 14 is a diagram showing an example of the coating material remaining in the internal flow passage of the head. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0007] <Painting equipment configuration> 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.

[0008] As shown in FIG. 1, the coating apparatus 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 controlled by the control device 40. For example, a valve type, piezoelectric type, or thermal type inkjet head can be used as the head 10. Using a piezoelectric type or thermal type inkjet head as the head 10 makes it easier to achieve high resolution.

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

[0011] The head 10 is supplied with a 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 a volatile component and a non-volatile component, and has fluidity. The tank may be a reservoir (not shown) contained in the head 10.

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

[0013] The coating material supplied to the discharge hole 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 the arm 21. The robot 20 is fixed to a floor surface, a wall surface, a ceiling surface, or the like. Note that there is no limit to the degree of freedom of the arm 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), a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), an input / output port, and various 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). The discharge control unit 42 controls the head 10 based on the setting information stored in the storage unit 45, and discharges the coating material 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 storage 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 will be described later.

[0017] The storage unit 45 corresponds to, for example, a ROM and a HDD. The ROM and the 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 the coating material by the head 10. The storage unit 45 also stores information related to the operation control of the multiple arms 21. The storage unit 45 may store data input by a user's instruction operation using a terminal device (not shown) as instruction data for operating the robot 20. The control unit 41 may also acquire setting information via another computer or a portable recording medium connected via a wired or wireless network.

[0018] 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 with the transport device stopped. 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 the transportation of the object 30 to be coated.

[0019] 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 coating layer 33. The substrate 31 is, for example, a steel plate processed into a predetermined shape, and is electrochemically treated to impart rust resistance as necessary. The primer layer 32 is provided, for example, to impart weather resistance, color development, and peel resistance. The first coating layer 33 is, for example, a base layer that has smoothness and weather resistance and imparts a desired coating color. The surface of the first coating layer 33 becomes the coating surface 30a to be coated by the coating device 1 according to the embodiment.

[0020] A second paint layer 34 is positioned on the first paint layer 33, which is the surface to be painted 30a. The second paint layer 34 is positioned so as to cover a part of the first paint layer 33 with a paint material having a paint color different from that of the first paint layer 33. As a result, the object to be painted 30 becomes a painted body 38 that is painted in a so-called two-tone color, in which 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 are aligned with an end 37 of the second paint layer 34 as a boundary.

[0021] In the example shown in Figure 2, the painting device 1 has been 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, for example, when positioning the first paint layer 33 on the painting surface 32a on the primer layer 32.

[0022] It should be noted that 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 surfaces of the regions 35 and 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).

[0023] <First embodiment> Fig. 3 is a diagram showing an example of a head of the coating apparatus according to the first embodiment. Fig. 3 corresponds to a plan view of the head 10 and the workpiece 30 facing the nozzle surface 12 (see Fig. 1) of the head 10, as viewed from the positive direction of the Z axis. For ease of explanation, it is assumed that the workpiece 30 has a planar shape along the XY plane, such as the roof of a car body.

[0024] In each embodiment described below, a case will be described as an example in which the head 10 ejects a coating material that positions the second coating layer 34 in the region 36. The coating apparatus 1 according to each embodiment has a common configuration except for the movement 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.

[0025] As shown in Fig. 3, the head 10 moves in the positive direction of the X-axis as a first direction while facing the workpiece 30. The head 10 moves in the positive direction of the X-axis as a first direction, for example, 1 m 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 head 10 needs to have a speed of, for example, 1.67×10 2 mm / s or more 41.67×10 2 It is sufficient to move the head 10 in the X-axis direction at a predetermined speed of mm / s or less. Note that this example uses one head 10, but the coating device 1 may use two or more heads 10.

[0026] 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 property 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.

[0027] In parallel with the movement in the positive X-axis direction, the head 10 also vibrates in the Y-axis direction as a second direction along the XY plane, so that the head 10 moves such that a locus 15 of the center 13 in a planar view describes a sinusoidal waveform.

[0028] In this way, by moving the head 10 in the first direction while vibrating in the second direction, even if a gap between the ejected droplets becomes large due to clogging of some of the ejection holes 11 (see FIG. 1), the gap can be filled by the ejected droplets ejected from the ejection holes 11 located adjacent to the clogged ejection hole 11. Therefore, the coating device 1 according to this embodiment can improve the coating quality.

[0029] Here, the amount of movement d1 in the Y-axis direction due to vibration of the head 10 can be set to 2 mm or less, for example, 0.07 mm or more and 2 mm or less, which makes it easier to fill in the gaps between the ejected droplets.

[0030] Furthermore, the vibration period T1 of the head 10 can be set to 2 mm or less, for example, 0.07 mm or more and 2 mm or less. By defining the vibration period T1 in this way, it becomes easier to fill in the gaps between the ejected droplets.

[0031] Furthermore, the lower limit of the movement amount d1 of the head 10 may be set based on the interval between the ejection holes 11 (see FIG. 1) aligned in a second direction intersecting the movement direction of the head 10. This point will be described with reference to FIG.

[0032] 4A to 4C are enlarged views for comparing the arrangement of droplets discharged onto a coating object. To facilitate easy illustration, each head 10 is shown having only one row (also called a "row") of discharge holes 11 aligned in the Y-axis direction intersecting with the moving direction 60 of the head 10. In addition, at points 17-1 and 17-2 adjacent to point 17-1, the head 10 is shown to have a discharge portion 16 (an example of a discharged droplet) where the coating material was discharged from the discharge holes 11, and a non-discharge portion 16a where the discharge portion 16 was supposed to be located but where the coating material was not discharged.

[0033] 4A, when the head 10 does not vibrate in the Y-axis direction, the non-ejection portions 16a continue along the movement direction 60 of the head 10. For this reason, the non-ejection portions 16a are easily visible as paint streaks.

[0034] On the other hand, as shown in Fig. 4B, by setting the movement amount d1 of the head 10 to be equal to or greater than the interval P1 between adjacent discharge parts 16 in the Y-axis direction, i.e., the interval between the discharge holes 11, the non-discharged parts 16a become discontinuous. Therefore, the non-discharged parts 16a become less visible as paint streaks, improving the coating quality. In particular, as shown in Fig. 4C, by setting the movement amount d1 of the head 10 to be equal to or greater than twice the interval P1 between adjacent discharge parts 16 in the Y-axis direction, i.e., the interval between the discharge holes 11, the non-discharged parts 16a become less visible, improving the coating quality, even if the non-discharged parts 16a are positioned side by side in the Y-axis direction as shown in the figure.

[0035] In the present embodiment, the vibration of the head 10 is exemplified by vibrating by a predetermined movement amount d1 in the second direction (Y-axis direction) that is a direction perpendicular to the first direction (X-axis direction), but is not limited thereto. For example, the head 10 may vibrate in a direction intersecting with the first direction. The head 10 may also vibrate in the second direction and alternately vibrate in a direction intersecting with the first direction, or may vibrate in a random direction. In this case as well, the non-ejection portion 16a becomes difficult to be visually recognized, improving the coating quality. Furthermore, the head 10 may vibrate in the Z-axis direction. In this case, for example, the size of the ejected droplets can be changed, improving the coating quality.

[0036] <Second embodiment> Fig. 5 is a diagram showing an example of a head included in a coating device according to a second embodiment. The head 10 shown in Fig. 5 rotates and swings along the XY plane about a swing axis c1 that passes through a center 13 and is aligned with the Z axis, in parallel with the movement in the positive direction of the X axis.

[0037] In this manner, by the head 10 moving in the first direction while rotating and oscillating, even if, for example, some of the ejection holes 11 (see FIG. 1) become clogged and the gap between the ejected droplets becomes large, the droplets ejected from the ejection holes 11 located adjacent to the clogged ejection hole 11 can fill the gap.

[0038] Here, the amount of movement d2 in the Y-axis direction due to the rotational swing of the head 10 can be 2 mm or less, for example, 0.07 mm or more and 2 mm or less. This makes it easier to fill the gaps between the ejected droplets. The swing angle θ1 can be set, for example, according to the arrangement of the ejection holes 11 in the head 10 as shown in FIG.

[0039] Fig. 6 is a diagram showing an arrangement of ejection holes in a head of a coating device according to an embodiment of the present invention. The head 10 shown in Fig. 6 corresponds to a perspective view of the arrangement of ejection holes 11 seen from the positive Z-axis direction side.

[0040] In the head 10 shown in Fig. 6, the discharge holes 11 are aligned along the Y-axis direction, while the discharge holes 11 are offset in the X-axis direction. The head 10 does not discharge the coating material from all of the discharge holes 11 at the same time, but discharges the coating material for each "row" aligned in the Y-axis direction when the head 10 moves in the movement direction 60 and reaches a predetermined position. This allows the discharge sections 16 to be positioned at intervals narrower than the intervals between the discharge holes 11 aligned on the XY plane.

[0041] Here, the oscillation angle θ1 (see FIG. 5) can be set based on a combination of ejection holes 11 that form adjacent ejection droplets and that are closest in distance in the movement direction 60. In the head 10 shown in FIG. 6, the oscillation angle θ1 (°) is defined so that Tanθ1≧y / x when the distances in the X-axis direction and Y-axis direction are x and y, respectively, in the ejection holes 11-1 and 11-2. This allows the ejection droplets ejected from the ejection holes 11 located adjacent to the clogged ejection hole 11 to cover the gap, even if some of the ejection holes 11 are clogged. The oscillation angle θ1 can be set to, for example, 0.2° to 5°.

[0042] Furthermore, the oscillation period T2 (see FIG. 5) of the head 10 can be set to 2 mm or less, for example, 0.07 mm or more and 2 mm or less. By defining the oscillation period T2 in this way, it becomes easier to fill in the gaps between the ejected droplets.

[0043] In the present embodiment, the head 10 is rotatably oscillated around the oscillation axis c1 at an oscillation angle θ1 on the XY plane, but the present invention is not limited to this. The head 10 may have a plurality of different oscillation axes c1 and may be rotatably oscillated randomly.

[0044] The oscillation axis c1 may be located at a position offset from the center 13 along the X-axis. Also, the oscillation axis c1 may be located at a position offset in the X-axis direction from the center 13. This point will be described with reference to FIG. 7.

[0045] FIG. 7 is a diagram showing an example of a head included in a coating device according to a modified example of the second embodiment. The head 10 shown in FIG. 7 rotates and swings around a swing axis c2 that is shifted from the center 13 toward the negative Y-axis direction. In the rotating and swinging head 10, centrifugal force is applied to the coating material discharged from the head 10 depending on the distance from the swing axis c2. For this reason, the shape of the discharged droplets discharged from the discharge holes 11 (see FIG. 1) located away from the swing axis c2 may be distorted. In contrast, the discharge holes 11 located near the swing axis c2 tend to discharge droplets of a desired shape. Therefore, for example, if the head 10 is moved along the X-axis direction while being rotated and swinging around the swing axis c2 near the end 37 with the region 35, the boundary between the regions 35 and 36 becomes sharp, improving the appearance.

[0046] As described above, by moving the head 10 in the first direction along the nozzle surface 12 while vibrating or rotatably swinging the head 10 along the nozzle surface 12 in a state in which the nozzle surface 12 and the workpiece 30 face each other, clogging of the discharge holes 11 is covered and the coating quality is improved. However, there are cases in which sufficient coating quality is not necessarily obtained by merely vibrating or rotatably swinging the head 10. This point will be described with reference to Figs. 8A to 8C.

[0047] 8A to 8C are enlarged views for comparing the arrangement of droplets discharged onto a workpiece. To facilitate easy illustration, the arrangement of paint droplets discharged from two discharge holes 11 aligned in the Y-axis direction intersecting with the moving direction 60 of the head 10 is illustrated as a discharge section 16. Also, Fig. 8A shows an example when the head 10 does not vibrate or rotate and oscillate, Fig. 8B shows an example when the head 10 vibrates, and Fig. 8C shows an example when the head 10 rotates and oscillates.

[0048] As shown in FIG. 8A, when the head 10 does not vibrate or rotate in the Y-axis direction, the gaps between adjacent discharge portions 16 along the movement direction 60 of the head 10 become continuous, which is easily visible as paint streaks.

[0049] 8B and 8C, when the head 10 vibrates or rotationally oscillates in the Y-axis direction, the intervals between the discharge portions 16 along the movement direction 60 become irregular, making it difficult to visually recognize the paint streaks. On the other hand, when the vibration of the head 10 causes the intervals between the discharge portions 16 positioned at an angle to the movement direction 60 to become regular, the paint streaks may become more easily recognized. In such cases, a countermeasure can be taken by making the vibration or rotationally oscillate of the head 10 a complex movement, as described below.

[0050] <Third embodiment> Fig. 9 is a diagram showing an example of a head included in a coating apparatus according to a third embodiment. The head 10 shown in Fig. 9 simultaneously performs the vibration described in the first embodiment and the rotational swing described in the second embodiment in parallel with the movement in the positive direction of the X-axis.

[0051] In this way, the head 10 moves in the first direction while vibrating and rotating, so that the droplets discharged from the nozzle holes 11 located near the clogged nozzle hole 11 can cover the gap, and the regularity of the droplets is broken, making paint streaks less visible. Therefore, the head 10 of the coating device 1 according to the third embodiment can improve the coating quality.

[0052] In addition, when the head 10 shown in FIG. 9 is vibrated and rotated so that the inclination with respect to the Y-axis direction, i.e., the swing angle, is maximized when the amount of movement in the Y-axis direction is maximized, clogging of the discharge holes 11 is easily covered, improving the coating quality.

[0053] In Fig. 9, the vibration period T1 (see Fig. 3) and the rocking period T2 (see Fig. 5) are the same, but they may be different. By making the vibration period T1, which is the period of vibration, and the rocking period T2, which is the period of rotational rocking, different in this way, paint streaks become even less visible, improving the paint quality.

[0054] 9 is illustrated as having an oscillation axis c3 that overlaps with the center 13 of the head 10, but this is not limited to this. The oscillation axis c3 may be located at a position offset from the center 13 along the X-axis. Moreover, the oscillation axis c1 may be located at a position offset from the center 13 in the X-axis direction.

[0055] <Fourth embodiment> Fig. 10 is a diagram showing an example of a head of a coating device according to a fourth embodiment. The head 10 shown in Fig. 10 vibrates at different periods in parallel with the movement in the positive direction of the X-axis. Note that the head 10 is not shown in Fig. 10.

[0056] 10, the center 13 of the head 10 moves along a trajectory 15. The trajectory 15 is a combination of a trajectory 15a of a first vibration with a movement amount d3 and a vibration period T3 and a trajectory 15b of a second vibration with a movement amount d4 and a vibration period T4.

[0057] In this way, the head 10 moves in the first direction while simultaneously vibrating at different periods, so that the droplets discharged from the nozzle holes 11 located near the clogged nozzle hole 11 can cover the gap and the paint streaks become less visible. Therefore, the head 10 of the coating device 1 according to the fourth embodiment can improve the coating quality.

[0058] Here, the movement amount d3 in the Y-axis direction due to the first vibration of the head 10 can be 2 mm or less, for example, 0.07 mm or more and 2 mm or less. This makes it easier to fill in the gaps between the ejected droplets. Also, the movement amount d4 in the Y-axis direction due to the second vibration of the head 10 can be 2 mm or less, for example, 0.07 mm or more and 2 mm or less. This makes it easier to fill in the gaps between the ejected droplets. Note that the movement amounts d3 and d4 may be the same as each other or may be different.

[0059] Moreover, the vibration period T3 of the first vibration of the head 10 can be set to 2 mm or less, for example, 0.07 mm or more and 2 mm or less. By specifying the vibration period T3 in this way, it becomes easier to fill the gaps between the ejected droplets. Moreover, the vibration period T4 of the second vibration of the head 10 can be set to 100 mm or more, for example, 100 mm or more and 500 mm or less. By specifying the vibration period T4 of the head 10 in this way, paint streaks become less visible.

[0060] <Fifth embodiment> 11 and 12 are diagrams showing an example of a head included in a coating device according to the fifth embodiment. The head 10 according to this embodiment moves such that a center 13 of the head 10 moves along an X-axis direction as a first direction along a surface 30a of an object 30 to be coated, specifically, along a trajectory 15 extending in the positive X-axis direction.

[0061] Fig. 11 corresponds to a plan view of head 10 as viewed from the positive direction of the Z axis. Fig. 12 corresponds to a front view of head 10 at each position (positions 10-4 to 10-1) of head 10 shown in Fig. 11 as viewed from the positive direction of the X axis along which head 10 moves.

[0062] As shown in FIG. 12, the head 10 rotates and swings along the YZ plane about a swing axis c4 that passes through the center 13 and runs along the X-axis direction, in parallel with the movement in the X-axis direction as the first direction.

[0063] In this way, the head 10 moves in the first direction while rotating and swinging about a swing axis along the first direction, so that the coating material in the nozzle, for example, swings and becomes less likely to dry in the nozzle.

[0064] Here, the vibration period T5 of the head 10 can be set to 2 mm or less, for example, 0.07 mm or more and 2 mm or less. By defining the vibration period T5 in this way, it becomes easier to fill in the gaps between the ejected droplets.

[0065] Furthermore, the oscillation angle θ2 can be set, for example, according to the arrangement of the ejection holes 11 (see FIG. 1) in the head 10. Specifically, when the ejection holes 11 of the head 10 are arranged as shown in FIG. 6, the oscillation angle θ2 (°) of the head 10 can be set, for example, so that θ2>y / x. This allows the ejection droplets ejected from the ejection holes 11 located adjacent to the clogged ejection holes 11 to cover the gap, even if some of the ejection holes 11 are clogged. The oscillation angle θ2 can be set, for example, to 0.2° to 5°.

[0066] Sixth embodiment 13 is a diagram showing an example of a head included in a coating apparatus according to a sixth embodiment. The head 10 according to this embodiment differs from the head 10 included in the coating apparatus 1 according to the fifth embodiment in that, instead of rotating and swinging about a swing axis c4, the head 10 vibrates in the Z-axis direction as a third direction so that the distance between the nozzle surface 12 and the surface 30a of the workpiece 30 changes.

[0067] Fig. 14 is a diagram showing an example of coating material remaining in an internal flow path of the head. As shown in Fig. 14, a nozzle 8 located inside the head 10 supplies coating material 18 to an outlet hole 11 located on a nozzle surface 12. When the head 10 vibrates in the Z-axis direction, a liquid surface 19 of the coating material 18 also moves in the Z-axis direction.

[0068] In this way, the head 10 moves in the X-axis direction as the first direction while vibrating in the Z-axis direction as the third direction, so that, for example, the coating material 18 in the nozzle 8 oscillates, making it difficult for the coating material 18 to dry in the nozzle 8. This reduces clogging of the discharge hole 11.

[0069] Here, the vibration period of the head 10 can be set to 2 mm or less, for example, 0.07 mm or more and 2 mm or less. By defining the vibration period in this way, it becomes easier to fill in the gaps between the ejected droplets.

[0070] In addition, the movement amounts d5 and d6 in the Z-axis direction due to the vibration of the head 10 can be set to 1 mm or less, for example, 0.07 mm or more and 1 mm or less. This can reduce unevenness in the coating. The movement amounts d5 and d6 may be the same or different.

[0071] The vibration in the Z-axis direction of the head 10 according to this embodiment can be combined with other vibrations and swings of the head 10 according to this embodiment as long as no contradiction occurs in the processing content.

[0072] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications are possible without departing from the spirit of the present invention. For example, in the above-mentioned embodiment, the coating device 1 equipped with the head 10 that dispenses a single color coating material has been described, but the coating device 1 may be equipped with a robot 20 that holds the head 10 that dispenses each of the basic colors of coating material, such as magenta (M), yellow (Y), cyan (C), and black (K).

[0073] As described above, the coating device according to the embodiment 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. With the nozzle surface facing the workpiece, the control unit moves the head in a first direction along the nozzle surface, vibrates the head in a second direction intersecting the first direction, and / or rotates and swings the head along the nozzle surface. This makes it possible to cover clogging of the discharge hole 11, improving the coating quality.

[0074] In the coating device according to the embodiment, the nozzle surface has a plurality of discharge holes for discharging the coating material, and the head vibrates and / or rotates and oscillates with a width equal to or greater than the interval between adjacent discharge holes in a second direction intersecting the first direction. This makes it easier to cover up clogging of the discharge holes 11, improving coating quality.

[0075] In addition, in the coating device according to the embodiment, the nozzle surface has a plurality of discharge holes for discharging the coating material, and the head vibrates and / or rotates and oscillates at a width at least twice the distance between adjacent discharge holes in a second direction intersecting the first direction. This makes it easier to cover up clogging of the discharge holes 11, improving coating quality.

[0076] In addition, in the coating device according to the embodiment, the head rotates and oscillates along the nozzle surface while vibrating in a second direction intersecting the first direction, which causes the regularity of the ejected droplets to be disrupted, making coating streaks less visible and improving coating quality.

[0077] In the coating device according to the embodiment, the head rotates and swings so that the inclination with respect to the second direction is maximized when the amount of movement in the second direction is maximized. This makes it easier to cover clogging of the discharge holes 11, improving coating quality.

[0078] In addition, in the coating device according to the embodiment, the vibration period of the head is different from the rotational oscillation period, which makes coating streaks less visible and improves coating quality.

[0079] In addition, in the coating device according to the embodiment, the head rotates and swings about an axis that is closer to the edge of the coating area than the center in a plan view, which improves the appearance of the edge of the coating area and improves coating quality.

[0080] In addition, in the coating device according to the embodiment, the head vibrates in a second direction intersecting the first direction and moves in the second direction at a period different from the period of the vibration, which makes paint streaks less visible and improves coating quality.

[0081] Moreover, the coating device according to the embodiment 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. With the nozzle surface facing the workpiece, the control unit moves the head in a first direction along the workpiece surface, while rotating and swinging the head around a swing axis along the first direction. This can reduce clogging of the discharge hole 11, improving coating quality.

[0082] In addition, in the coating device according to the embodiment, the head vibrates in a third direction intersecting the first direction so as to change the distance between the nozzle face and the workpiece, thereby reducing clogging of the discharge holes 11 and improving coating quality.

[0083] Further advantages and modifications may readily occur to those skilled in the art. Thus, 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 equivalents thereof. [Explanation of symbols]

[0084] 1. Painting equipment 10 Head 11 Discharge hole 12 Nozzle surface 16 Discharge part 16a Non-discharge area 20. Robot 21 Arm 30 Object to be painted 30a Surface to be painted 40 Control device 41 Control section 42 Discharge control section 43 Motion control section 45 Storage section

Claims

1. 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, while the nozzle surface and the object to be coated are opposed to each other, moves the head in a first direction along the surface to be coated of the object to be coated, and rotates and swings the head around a swing axis along the first direction, The head vibrates in a third direction intersecting the first direction so that a distance between the nozzle surface and the workpiece changes. Painting equipment.

2. The head rotates and swings in the range of 0.2° to 5°. The coating device according to claim 1.

3. The head vibrates in the third direction at a period of 2 mm or less.

3. A coating apparatus according to claim 1 or 2.

4. The resolution of the head is 150 dpi or more. The coating device according to any one of claims 1 to 3.

5. a step of opposing a nozzle surface of the head to an object to be coated; a step of rotating and swinging the head around a swing axis along a first direction while moving the head in a first direction along a surface to be coated of the object to be coated; vibrating the head in a third direction intersecting the first direction so that a distance between the nozzle surface and the workpiece is changed; a step of discharging a coating material from the nozzle surface while moving the head; A painting method comprising:

6. The head vibrates in the third direction with a period of 2 mm or less. The coating method according to claim 5.

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