Powder coating apparatus and powder coating method

Abstract

The present invention aims to provide a powder coating apparatus and method that can more evenly coat a workpiece. To address this issue, a powder coating apparatus 1 comprises: a powder flow trough 10 storing resin powder; a workpiece gripper 60 gripping a stator W; and a workpiece transport unit 50 transporting the workpiece gripper 60 such that at least a portion of the stator W gripped by the workpiece gripper 60 is immersed in the resin powder within the powder flow trough 10. Furthermore, the workpiece gripper 60 includes a vibration mechanism 64 for vibrating the stator W.

Description

Technical Field

[0001] The present invention relates to a powder coating device and a powder coating method. Background Art

[0002] Conventionally, the fluidization dipping method has been used to apply insulating powder to workpieces such as the coil ends of stators, a component of motors mounted on vehicles. Patent Document 1 describes a powder coating apparatus comprising a powder flow trough having a first partition plate and a second partition plate, each of which is a porous plate; and a vibrating mechanism connected to the bottom surface of the powder flow trough.

[0003] [Prior Art Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent No. 6596477 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] Incidentally, in the apparatus described in Patent Document 1, air is circulated through a porous plate and a powder flow trough is vibrated to flow the resin powder within the trough, thereby applying the resin powder to the workpiece. However, this method partially concentrates the vibration function on the powder flow trough side, vibrating the powdered resin within the trough that has separated from the workpiece. This makes it difficult to reproduce optimal vibration conditions, and there is room for improvement in achieving more uniform coating of the workpiece.

[0008] An object of the present invention is to provide a powder coating apparatus and a powder coating method that can coat a workpiece more uniformly.

[0009] [Technical means to solve the problem]

[0010] One embodiment of the present invention relates to a powder coating device comprising: a powder flow trough for storing resin powder; a workpiece gripping portion for gripping a workpiece; and a workpiece conveying portion for conveying the workpiece gripping portion and immersing at least a portion of the workpiece gripped by the workpiece gripping portion in the resin powder in the powder flow trough; and the workpiece gripping portion has a vibration mechanism for applying vibration to the workpiece.

[0011] Alternatively, the workpiece transporting portion can move the workpiece gripping portion up and down in a state where at least a portion of the workpiece gripped by the workpiece gripping portion is immersed in the resin powder in the powder flowing trough.

[0012] Another embodiment of the present invention relates to a powder coating method, which uses a powder coating device to coat resin powder on a workpiece, the powder coating device comprising: a powder flow trough for storing resin powder; a workpiece gripping portion for gripping the aforementioned workpiece; and a workpiece conveying portion for conveying the aforementioned workpiece gripping portion; and, the powder coating method applies resin powder while applying vibration to the aforementioned workpiece from the aforementioned workpiece gripping portion while immersing at least a portion of the aforementioned workpiece gripped by the aforementioned workpiece gripping portion in the resin powder in the aforementioned powder flow trough.

[0013] Alternatively, while at least a portion of the workpiece gripped by the workpiece gripping portion is immersed in the resin powder in the powder flowing trough, the resin powder is applied while the workpiece gripping portion is moved up and down by the workpiece conveying portion.

[0014] (Effects of the Invention)

[0015] According to the present invention, a powder coating apparatus and a powder coating method capable of coating a workpiece more uniformly can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram showing a powder coating apparatus according to one embodiment of the present invention.

[0017] Figure 2 It is a three-dimensional diagram showing a stator.

[0018] Figure 3 This is an exploded perspective view showing the stator core and coils.

[0019] Figure 4 This is a perspective view showing a conductor segment group inserted into a slot of a stator core in a stator.

[0020] Figure 5 This is an enlarged perspective view of the coil end before applying insulating powder.

[0021] Figure 6 This is a magnified perspective view of the coil end after coating with insulating powder.

[0022] Figure 7 The figure shows a cross-sectional view of a powder flow channel and a workpiece gripping portion of a powder coating apparatus according to one embodiment of the present invention.

[0023] Figure 8 The powder flow channel is viewed from the side Figure 7 FIG. 1 is a diagram of a stator being gripped by a workpiece gripper as shown in FIG.

[0024] Figure 9 This is a diagram showing a flow chart of a powder coating method according to one embodiment of the present invention. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0026] Reference Figure 1 The powder coating apparatus 1 according to this embodiment will be described. Figure 1 1 is a schematic diagram illustrating a powder coating apparatus 1. In the orthogonal coordinate system XYZ shown in the figure, one direction parallel to the horizontal plane is defined as the X-axis direction, a direction in the horizontal plane perpendicular to the X-axis direction is defined as the Y-axis direction, and a vertical direction is defined as the Z-axis direction.

[0027] The powder coating device 1 is a device for coating resin powder on a workpiece using a fluidized dipping method. Figure 1 As shown, the powder coating device 1 includes: a powder flow trough 10, a base portion 20 supporting the powder flow trough 10 on a setting surface, a dust collecting mechanism 30, a level meter 40 for detecting the height of the powder surface of the powder flow trough 10, a multi-joint robot 100 and a control device 70.

[0028] The following describes a case where a stator W, a component of a motor mounted on a vehicle, is used as a workpiece and insulating powder is used as the resin powder. However, the workpiece and the resin powder are not particularly limited. Examples of the resin constituting the insulating powder include epoxy resins.

[0029] The powder flow trough 10 is generally circular in plan view. It includes a cylindrical main body 11, a generally disc-shaped bottom plate 12, and a generally disc-shaped first partition plate 13 and a second partition plate 14 disposed within the main body 11. The first partition plate 13 and the second partition plate 14 are porous plates each having pores smaller than the particle size of the insulating powder.

[0030] The powder storage section 15, which stores insulating powder, is defined by the edge 11a of the main body 11 and the second partition plate 14. Furthermore, the first air chamber 16 is defined by the bottom plate 12 and the first partition plate 13, and the second air chamber 17 is defined by the first partition plate 13 and the second partition plate 14. Air is supplied from an air supply device 19 to the first air chamber 16 at a predetermined rate via an air supply port 18. The air supplied to the first air chamber 16 flows through the first partition plate 13 into the second air chamber 17, and then through the second partition plate 14 into the powder storage section 15. As a result, the insulating powder stored in the powder storage section 15 is circulated.

[0031] The pedestal 20 includes fixing frames 21 and 22 , a fixing plate 23 , and connecting members 24 and 25 connecting the fixing frames 21 and 22 and the fixing plate 23 .

[0032] The fixing frames 21 and 22 extend in the vertical direction, and the lower ends of the fixing frames 21 and 22 are fixed to the installation surface.

[0033] The fixing plate 23 is generally disc-shaped when viewed from above and is positioned approximately coaxially with the central axis of the powder flow channel 10. The fixing plate 23 extends horizontally. The powder flow channel 10 is disposed on the upper surface of the fixing plate 23. The diameter of the fixing plate 23 is greater than the diameter of the bottom plate 12 of the powder flow channel 10. Furthermore, a plurality of through-holes are formed on the upper surface of the fixing plate 23.

[0034] The connecting member 24 is shaft-shaped, with its upper end fixed to the bottom surface of the fixing plate 23 and its lower end fixed to the upper end of the fixing frame 21. The connecting member 25 is shaft-shaped, with its upper end fixed to the bottom surface of the fixing plate 23 and its lower end fixed to the upper end of the fixing frame 22.

[0035] The dust collection mechanism 30 includes a dust-proof wall 31, a dust hopper 32, and a dust collector 33. The dust-proof wall 31 extends upward from the upper surface of the fixed plate 23, surrounding the outer side of the powder flow trough 10. The upper end of the dust hopper 32 is fixed to the bottom surface of the fixed plate 23. The insulating powder flowing out of the powder flow trough 10 and between the dust-proof wall 31 is collected in the dust hopper 32. The insulating powder collected in the dust hopper 32 is captured by the dust collector 33 via the dust collection pipe 34.

[0036] The level meter 40 is disposed above the powder flow trough 10. The level meter 40 detects the height of the powder surface in the powder flow trough 10, for example, using triangulation, and transmits a signal corresponding to the detected value to the control device 70. The height of the powder surface is the distance from a predetermined reference (e.g., the edge 11a of the main body 11). The level meter 40 measures the height of the powder surface based on the position of the image formed on the light receiving element by the laser light reflected by the powder surface when the laser light is irradiated from the light source toward the measurement position.

[0037] The multi-joint robot 100 includes a workpiece transport unit 50 and a workpiece gripping unit 60, and is a device capable of gripping and transporting a stator W as a workpiece. Figures 2 to 6 The details of the structure of the stator W will be described.

[0038] The stator W is, for example, a stator of a rotating electrical machine, and includes a stator core W1 and a coil W2 attached to the stator core W1. The lower end of the coil W2 is a coil end W3 coated with insulating powder.

[0039] The stator core W1 includes an annular portion W11 formed, for example, from a stack of multiple thin-walled core plates. The annular portion W11 has a through-hole W14 extending axially through the center and a plurality of slots W12 extending axially therethrough. The slots W12 are radially arranged at regular intervals along the circumference of the annular portion W11 and have openings W13 that open toward the inner circumference of the annular portion W11. The stator core W1 of this embodiment has 48 slots W12, but the number of slots W12 is not limited.

[0040] The coil W2 is composed of a plurality of conductor segments W20, for example. The plurality of conductor segments W21 are formed by overlapping a plurality of conductor segments W21 formed by forming a conductor composed of a flat wire having a rectangular cross section into a substantially U-shaped shape. Figure 3 As shown, the conductor segments W21 are inserted into the slots W12 along the axial direction of the stator core W1. The conductor segments W21 inserted into the slots W12 are joined by bending the ends protruding outward in the axial direction of the stator core W1 from the side opposite to the insertion side and laser welding the bent ends to each other.

[0041] Specifically, the conductor segment W21 before being inserted into the slot W12 of the stator core W1 has a pair of parallel straight portions W22, W22 and a U-shaped portion W23 connecting one end portion of the straight portions W22, W22. Figure 2 As shown, conductor segments W21 are assembled to the stator core W1 by inserting a pair of straight portions W22, W22 into different slots W12, W12. The straight portions W22 of multiple conductor segments W21 are inserted into a single slot W12 so that they overlap in the radial direction of the stator core W1. Straight portions W22 of conductor segments W21 with different phases are arranged in adjacent slots W12, W12 in the circumferential direction of the stator core W1.

[0042] like Figure 5 As shown, after coil W2 is inserted into slot W12, the end of the straight portion W22 protruding from slot W12 is bent obliquely along the circumferential direction to form an oblique portion W24. Furthermore, the front end of oblique portion W24 is bent so as to rise axially along the stator core W1 to form a rising portion W25. In other words, the oblique portion W24 and rising portion W25 form the coil end W3 of coil W2.

[0043] A pair of rising portions W25, W25 of the coil W2 are bent toward each other from the slot W12 by a pair of diagonal portions W24, W24, overlapping and arranged in the radial direction of the stator core W1. This gives each coil W2 a ring shape. Multiple coils W2 are connected by laser welding or other methods to join the rising portions W25, W25 of the same-phase coils W2 stacked in the radial direction of the stator core W1. This creates a complex, intertwined shape of the coil end W3, with multiple diagonal portions W24 and rising portions W25 stacked in the radial direction of the stator core W1.

[0044] The insulating coating W26 is formed on the coil W2, but a peeling portion W27 is formed on the rising portion W25 of the coil end W3 where the insulating coating W26 is peeled off. In order to insulate the peeling portion W27, insulating powder is applied to the intricately shaped coil end W3. After the insulating powder is applied, Figure 6 As shown, an insulating layer W29 is formed on the surface of the coil end W3.

[0045] Next, the structure of the multi-joint robot 100 will be described. Figure 1 As shown, the multi-joint robot 100 includes a workpiece transport unit 50 and a workpiece gripping unit 60 .

[0046] The workpiece transport unit 50 includes a base 51 and an arm 52 rotatably supported by the base 51 .

[0047] The arm 52 includes a first arm 525 , a second arm 526 , a third arm 527 , a first joint 521 , a second joint 522 , a third joint 523 , and a connecting member 524 rotatably supported on the base 51 .

[0048] The first arm portion 525 is supported so as to be rotatable relative to the base 51 with the substantially vertical direction as the rotation axis.

[0049] The second arm portion 526 is connected to the first arm portion 525 via the first joint portion 521 , and is supported so that the angle relative to the first arm portion 525 can be changed with the first joint portion 521 serving as a fulcrum.

[0050] The third arm portion 527 is connected to the second arm portion 526 via the second joint portion 522 , and is supported so that the angle relative to the second arm portion 526 can be changed with the second joint portion 522 serving as a fulcrum.

[0051] The connecting member 524 is connected to the third arm portion 527 via the third joint portion 523. The connecting member 524 is supported in the third joint portion 523 so as to be rotatable about the extension direction of the third arm portion 527. The workpiece gripping portion 60 is connected to the arm portion 52 via the connecting member 524. That is, the workpiece transporting portion 50 can move the workpiece gripping portion 60 horizontally by rotating the first arm portion 525 relative to the base 51, and can move the workpiece gripping portion 60 vertically using the first joint portion 521 and the second joint portion 522. Furthermore, the workpiece transporting portion 50 can flip the workpiece gripping portion 60 around the third joint portion 523 as a fulcrum.

[0052] Next, the workpiece gripping portion 60 will be described. Figure 7 It is a cross-sectional view showing the powder flow trough 10 and the workpiece gripping portion 60 of the multi-joint robot 100 , and illustrates a state where the coil end W3 is coated. Figure 8 The powder flow channel 10 is viewed from the side of the powder flow channel 10. Figure 7 FIG. 2 is a diagram of a stator W gripped by a workpiece gripper 60 as shown in FIG.

[0053] The workpiece gripping portion 60 is fixed to the connecting member 524 of the arm portion 52. The workpiece gripping portion 60 includes a workpiece tray 80, a fixed panel 61, an elastic member 62, a clamping mechanism 63, and a vibration mechanism 64. Figure 7 As shown, in this embodiment, the coil end W3 is immersed in the powder reservoir 15 and coated while the axial direction of the stator W gripped by the work gripper 60 is substantially parallel to the axial direction of the powder flow channel 10 .

[0054] The workpiece pallet 80 has an annular shape and is formed so as to be connectable to the end portion of the stator W on the opposite side to the coil end portion W3 . The workpiece pallet 80 is gripped by the gripping mechanism 63 .

[0055] The fixed panel 61 is fixed to the end portion 528 of the connecting member 524 on the opposite side to the third arm portion 527 using screws. The elastic member 62 is attached to the surface of the fixed panel 61 on the opposite side to the surface fixed to the end portion 528.

[0056] The elastic member 62 suppresses the transmission of vibration to the workpiece conveying portion 50. As the elastic member 62, for example, a rubber member is used. A clamping mechanism 63 is mounted on the elastic member 62 on the opposite side of the surface on which the panel 61 is mounted. Figure 7 As shown, the fixed panel 61, the elastic component 62 and the clamping mechanism 63 are fixed to each other using screws.

[0057] The clamping mechanism 63 is configured to be able to grip the workpiece pallet 80 to which the stator W is mounted. The clamping mechanism 63 includes a clamping plate 631 , a claw portion 636 , and a clamping cylinder 635 .

[0058] The clamping plate 631 is substantially disc-shaped, with the elastic member 62 fixed to one side surface 632 in the thickness direction and a plurality of protruding pieces 634 formed on the other side surface 633 in the thickness direction. The protruding pieces 634 are formed on the peripheral edge of the clamping plate 631 .

[0059] The claw portion 636 is plate-shaped and is disposed opposite to the protruding piece 634 with a gap therebetween. The claw portion 636 is disposed at a position overlapping with a portion of the protruding piece 634 when viewed from the powder flow channel 10 side.

[0060] One end of the clamping cylinder 635 is connected to the peripheral edge of the clamping plate 631, and the other end is connected to the claw 636. The clamping mechanism 63 is able to grip the stator W by placing the workpiece pallet 80, to which the stator W is mounted, between the protruding piece 634 and the claw 636 and activating the clamping cylinder 635. The clamping mechanism 63 is able to grip the stator W so that the axial direction of the stator W is approximately parallel to the central axis of the clamping plate 631.

[0061] The vibration mechanism 64 applies vibration to the stator W gripped by the clamping mechanism 63 . The vibration mechanism 64 includes a first vibrator 641 , a second vibrator 642 , a bracket 643 to which the second vibrator 642 is fixed, and a vibrometer 646 .

[0062] The first vibrator 641 is fixed to the side surface 632 of the peripheral portion of the clamping plate 631 using screws. Figure 7 As shown by the hollow arrow in FIG, the first exciter 641 can apply the axial vibration of the stator W grasped by the clamping mechanism 63 to the stator W. That is, as Figure 7 As shown in FIG, the first vibrator 641 can apply vertical vibration to the coil end W3 immersed in the powder storage unit 15 .

[0063] The second exciter 642 is fixed to the other side surface 633 on the center side of the clamping plate 631 via a bracket 643. Figure 2 As shown by the hollow arrow in FIG, the second exciter 642 can apply radial vibration of the stator W grasped by the clamping mechanism 63 to the stator W. That is, as Figure 7 As shown in FIG, the second vibrator 642 can apply horizontal vibration to the coil end W3 immersed in the powder storage unit 15 .

[0064] The bracket 643 is formed as a whole into a generally L-shaped cross-section. Specifically, the bracket 643 includes a first plate-shaped member 644 fixed to and extending along the other side surface 633 of the clamping plate 631, and a second plate-shaped member 645 extending from one end of the first plate-shaped member 644 in a direction generally perpendicular to the clamping plate 631. The second vibrator 642 is fixed to the second plate-shaped member with screws while in contact with the first plate-shaped member 644 and the second plate-shaped member 645.

[0065] like Figure 8 As shown, the vibration meter 646 is installed near the three-phase line portion W28 of the coil end W3, detects the vibration applied to the stator W, and sends a signal corresponding to the detection value to the control device 70.

[0066] The control device 70 includes, for example, a microcomputer having a central processing unit (CPU), a memory such as a read-only memory (ROM) or a random-access memory (RAM), an input / output port, and various circuits. The control device 70 controls the air supply speed of the air supply device 19 and the drive of the workpiece transport unit 50 of the multi-joint robot 100, the drive of the clamping mechanism 63 of the workpiece gripping unit 60, and the drive of the vibration mechanism 64 according to a predetermined program. Specifically, for example, the control device 70 can control the drive of the arm 52, etc., so that the workpiece transport unit 50 moves the workpiece gripping unit 60 up and down while the coil end W3 gripped by the workpiece gripping unit 60 is immersed in the insulating powder in the powder flow tank 10. In addition, the control device 70 can control the drive of the vibration mechanism 64 and adjust the vibration frequency of the first exciter 641 and the second exciter 642.

[0067] Next, refer to Figure 9 The powder coating method according to this embodiment will be described. Figure 9 This is a flow chart showing the process of the powder coating method.

[0068] The powder coating method of this embodiment includes: a heating step of heating the stator W; a powder coating step of coating insulating powder on the coil end W3 of the stator W; and a reheating step of reheating the stator W after coating the coil end W3 with insulating powder.

[0069] In the heating step, the stator W is heated in a powder preheating furnace until the coil end W3 reaches a temperature at which the insulating powder can be melted.

[0070] During the powder coating process, the control device 70 drives the arm 52 of the workpiece transport unit 50, etc., to transport the stator W, heated in the powder preheating furnace, while being gripped by the workpiece gripper 60, to a position near the top of the powder flow trough 10. At this time, the stator W is gripped by the workpiece gripper 60 with the coil end W3 facing upward.

[0071] After the stator W is transported to the top of the powder flow trough 10, the control device 70 controls the arm 52 to rotate the workpiece gripper 60 with the third joint 523 as the fulcrum. As a result, the coil end W3 of the stator W, gripped by the workpiece gripper 60, faces the powder surface within the powder reservoir 15 of the powder flow trough 10.

[0072] After the stator W is flipped, the control device 70 controls the drive of the arm 52 to immerse the coil end W3 of the stator W in the powder flow trough 10. The control device 70 controls the drive of the workpiece transport unit 50 so that, while the coil end W3 is immersed in the insulating powder in the powder flow trough 10, the vibration mechanism 64 vibrates the stator W and the workpiece transport unit 50 moves the workpiece gripper 60 up and down.

[0073] After a predetermined time has passed, the control device 70 controls the driving of the workpiece transporting portion 50 to lift the stator W in the powder storage portion 15 to above the powder flow trough 10 .

[0074] The stator W is lifted above the powder flow trough 10 and waits for a predetermined period of time. The control device 70 then controls the workpiece transport unit 50 to re-immerse the coil end W3 of the stator W in the powder flow trough 10. The control device 70 controls the workpiece gripping unit 60 and the workpiece transport unit 50 so that, while the coil end W3 is immersed in the insulating powder in the powder flow trough 10, the vibration mechanism 64 vibrates the stator W and the workpiece transport unit 50 moves the workpiece gripping unit 60 up and down.

[0075] After a predetermined time has passed, the control device 70 controls the driving of the workpiece transporting portion 50 to lift the stator W in the powder storage portion 15 to above the powder flow trough 10 .

[0076] After a predetermined time has passed, the control device 70 drives the arm 52 and the like of the workpiece transporting unit 50 to transport the stator W to the powder curing furnace and reverse the stator W so that the coil end W3 faces upward.

[0077] During the reheating process, the control device 70 drives the arm 52 of the workpiece transport unit 50 and other components to transport the stator W into the powder curing furnace. Then, within the powder curing furnace, the stator W, with the insulating powder welded to the coil end W3, is reheated, forming an insulating layer W29 on the coil end W3.

[0078] In conventional powder coating apparatuses and methods, the pores of the porous plates can become clogged due to the axial vibration of the powder flow trough 10. These conventional coating apparatuses and methods circulate air through porous plates such as the first partition plate 13 and the second partition plate 14, vibrating the powder flow trough 10 to flow the resin powder within the trough 10. In particular, when the powder flow trough 10 performs a conical motion, a difference in axial vibration occurs between the central axis and the peripheral edges of the porous plates, increasing the difference in the pore blockage rate between the central axis and the peripheral edges. As a result, radial flow occurs on the powder surface within the powder flow trough 10, reducing the quality of the powder coating.

[0079] In contrast, the powder coating apparatus 1 of this embodiment includes a powder flow trough 10 that stores resin powder; a workpiece gripper 60 that grips a stator W; and a workpiece transport unit 50 that transports the workpiece gripper 60 and immerses at least a portion of the stator W gripped by the workpiece gripper 60 in the insulating powder within the powder flow trough 10. Furthermore, the workpiece gripper 60 includes a vibration mechanism 64 that applies vibration to the stator W. This allows vibration to be generated between the stator W and the insulating powder without vibrating the powder flow trough 10, which stores the insulating powder. In other words, rather than shaking the entire powder flow trough 10 to fluidize the insulating powder within the trough, vibrating the immersed product achieves fluidization similar to vibrating the powder flow trough 10. Consequently, radial flow of the powder surface caused by the vibration of the powder flow trough 10 can be suppressed, enabling more uniform coating even on intricately shaped coating areas, such as the coil end W3. Furthermore, since vibration is applied directly to the stator W, it is easy to optimize the vibration between the stator W and the insulating powder, enabling high-quality powder coating. Furthermore, since vibration can be generated between the workpiece and the powder flow trough without vibrating the powder flow trough itself, degradation of the porous plate caused by pore blockage due to axial vibration of the powder flow trough can be suppressed, thereby extending the life of the porous plate.

[0080] In the powder coating apparatus 1 of this embodiment, the workpiece transport unit 50 is capable of vertically moving the workpiece gripping unit 60 while at least a portion of the stator W gripped by the workpiece gripping unit 60 is immersed in the insulating powder within the powder flow trough 10. This causes the stator W immersed in the insulating powder within the powder flow trough 10 to vibrate and vertically move while immersed in the insulating powder. This allows the stator W to pass between the plurality of conductor segments W21, as in the case of the coil end W3, and to be fed to a position further inward from the coil end W3.

[0081] The powder coating method of this embodiment applies insulating powder to a stator W using a powder coating apparatus 1. The powder coating apparatus 1 includes a powder flowing trough 10 storing resin powder, a workpiece gripping unit 60 for gripping the stator W, and a workpiece transporting unit 50 for transporting the workpiece gripping unit 60. The powder coating method applies resin powder while vibrating the stator W using the workpiece gripping unit 60, while at least a portion of the stator W, held by the workpiece gripping unit 60, is immersed in the resin powder within the powder flowing trough 10. This allows vibration to be generated between the stator W and the insulating powder without vibrating the powder flowing trough 10 storing the insulating powder. This suppresses radial flow of the powder surface and allows for more uniform coating even on intricately shaped coating areas, such as the coil end W3. Furthermore, since vibration is applied directly to the stator W, it is easy to optimize the vibration between the stator W and the insulating powder, enabling high-quality powder coating. In addition, since vibration can be generated between the workpiece and the powder flow trough without vibrating the powder flow trough, the deterioration of the porous plate caused by the blockage of the pores due to the axial vibration of the powder flow trough can be suppressed, and the life of the porous plate can be extended.

[0082] In the powder coating method of this embodiment, insulating powder is applied while at least a portion of the stator W, gripped by the workpiece gripper 60, is immersed in the resin powder within the powder flow trough 10. This causes the workpiece gripper 60 to be moved vertically by the workpiece transport unit 50 while being moved vertically. This causes the stator W, immersed in the insulating powder within the powder flow trough 10, to vibrate and vertically move while immersed in the insulating powder. This allows the insulating powder to be fed to a position inward of the coil end W3, passing between the plurality of conductor segments W21, as occurs at the coil end W3.

[0083] As mentioned above, although embodiment of this invention was demonstrated, this invention is not limited to the said embodiment, The said embodiment can also be modified suitably within the range of the summary of this invention.

[0084] In the above embodiment, while at least a portion of the stator W gripped by the workpiece gripping portion 60 is immersed in the resin powder in the powder flow trough 10, the resin powder is applied while the workpiece gripping portion 60 is moved up and down by the workpiece conveying portion 50. However, the resin powder can also be applied without moving the workpiece gripping portion 60 up and down, or the resin powder can be applied while the workpiece gripping portion 60 is moved in the horizontal direction.

[0085] Reference numerals

[0086] 1 Powder coating equipment

[0087] 10 Powder flow channel

[0088] 50 Workpiece handling department

[0089] 60 Workpiece gripping unit

[0090] W stator (workpiece)

Claims

1. A powder coating device comprising: Powder flow trough, storing resin powder; A workpiece gripping portion, for gripping a workpiece; a workpiece transporting portion that transports the workpiece gripping portion and immerses at least a portion of the workpiece gripped by the workpiece gripping portion in the resin powder in the powder flow tank; and control device; and, The workpiece gripping portion includes a vibration mechanism for applying vibration to the workpiece. The vibration mechanism includes: a first vibration exciter for applying vertical vibration to the workpiece; and a second vibration exciter for applying horizontal vibration to the workpiece. The control device controls the driving of the workpiece conveying portion to move the workpiece gripping portion up and down, and controls the driving of the vibration mechanism of the workpiece gripping portion to apply vertical and horizontal vibrations to the workpiece, while at least a portion of the workpiece gripped by the workpiece gripping portion is immersed in the resin powder in the powder flow trough.

2. A powder coating method, comprising applying resin powder to a workpiece using a powder coating apparatus, wherein the powder coating apparatus comprises: a powder flow trough for storing the resin powder; a workpiece gripping portion for gripping the workpiece; and a workpiece conveying portion for conveying the workpiece gripping portion; and In a state where at least a portion of the workpiece gripped by the workpiece gripping portion is immersed in the resin powder in the powder flow trough, the resin powder is applied while the workpiece gripping portion is moved up and down by the workpiece conveying portion, and the resin powder is applied while the workpiece is subjected to vertical and horizontal vibrations by the workpiece gripping portion.

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