Enameled copper flat wire varnishing process and device

Abstract

The invention discloses an enamelled copper flat wire varnishing process and device, a moving route of a copper flat wire (1) on a production line is bent to form N U-shaped channels, the N channels are connected in series, an enamelled wire firstly moves downwards to enter the channels and then moves upwards to leave the channels from the moving direction of the copper flat wire (1), and then the enamelled wire is varnished. Paint with the solid content of 35%-45% is painted on the copper flat wire (1) at the starting points of the second channel to the (N-1) th channel, paint with the solid content of 25%-30% is painted on the copper flat wire (1) at the starting point of the Nth channel, and the paint is dried at the channels; the paint is polyimide paint, and the paint is firstly heated for more than 15 seconds at the temperature of 180-240 DEG C in the channel and then heated for more than 30 seconds at the temperature of 350-400 DEG C. The device has the advantages of reducing the length of a production line, improving the yield of enameled wires and reducing energy consumption.

Description

Technical Field

[0001] The invention belongs to the field of enameled copper flat wires, and in particular relates to an enameled copper flat wire varnishing process and device. Background Art

[0002] Enameled copper flat wire (enameled wire for short) is widely used in the hub motors of new energy vehicles. With the development of new energy vehicles, more and more high-power hub motors have been developed. High-power hub motors have put forward more stringent requirements on the electrical properties of enameled wire, including the electrical properties of the paint film on the outer layer of the enameled wire (including voltage resistance, corona resistance, etc.).

[0003] In order to improve the electrical performance of the paint film, the usual practice is to increase the thickness of the paint film. The current method to increase the thickness of the paint film is usually to increase the number of times the enameled wire is painted on the production line. The movement direction of the enameled wire is basically horizontal, but each additional coat of paint requires a corresponding increase in a set of painting equipment and drying equipment, resulting in a very long production line for the enameled wire, which is not conducive to site layout.

[0004] In addition, the paint currently used has a low solid content (about 30%), which is mainly to make the paint have good self-leveling properties and form a paint film with relatively uniform thickness. However, compared with the round-core enameled wire, the flat-core enameled wire has edges and corners. When the paint self-levels, there is greater resistance at the edges and corners, which will still lead to uneven distribution of paint film thickness. The paint will be concentrated on the two edges at the bottom of the enameled wire under the action of gravity, resulting in a low yield of the enameled wire. Summary of the invention

[0005] The object of the present invention is to provide a process and device for painting enameled copper flat wires. The present invention has the advantages of reducing the length of the production line, improving the yield of the enameled wires and reducing energy consumption.

[0006] The technical solution of the present invention is as follows: a coating process for enameled copper flat wires, wherein the moving route of the copper flat wires on the production line is bent to form N U-shaped channels, and the N channels are connected in series. From the perspective of the moving direction of the copper flat wires, the enameled wires first move downward to enter the channels, and then move upward to leave the channels. At the starting points of the 2nd to N-1th channels, paint with a solid content of 35%-45% is applied to the copper flat wires, and at the starting point of the Nth channel, paint with a solid content of 25%-30% is applied to the copper flat wires, and the paint is dried at the channels.

[0007] In the aforementioned process of painting the enameled copper flat wire, the paint is polyimide paint, and the paint is first heated in the channel at a temperature of 180-240° C. for more than 15 seconds, and then heated at a temperature of 350-400° C. for more than 30 seconds.

[0008] The device for realizing the aforementioned enameled copper flat wire painting process comprises a box body, in which a first chamber, a second chamber, a third chamber and a fourth chamber are arranged in sequence from top to bottom, a smoke exhaust pipe is arranged on the top of the first chamber, N+1 horizontally distributed upper guide wheels are arranged in the first chamber, N horizontally distributed lower guide wheels are arranged in the fourth chamber, and heaters are arranged in the second chamber and the third chamber. The copper flat wire enters the first chamber, alternately bypasses the upper guide wheels and the lower guide wheels, and then leaves the first chamber. N-1 painting devices are arranged in the first chamber, and the N-1 painting devices are respectively located below the outlet side of the 2nd to N-1th upper guide wheels.

[0009] In the aforementioned device, a dehumidification pipe is provided on the outside of the box body, both ends of the dehumidification pipe are connected to the second chamber, and a first fan and a dehumidification filter are provided on the dehumidification pipe.

[0010] In the aforementioned device, the first chamber is provided with a first air inlet, the smoke exhaust pipe is provided with a second fan, and the fourth chamber is provided with a second air inlet.

[0011] In the aforementioned device, the painting device includes a paint overflow box with an opening at the top, a paint block is provided in the middle of the paint overflow box, a wire passing hole is provided vertically on the paint block, the upper and lower ends of the wire passing hole are both trumpet-shaped, the middle part of the wire passing hole shrinks inward to form a wire passing hole that cooperates with the copper flat wire, and a paint touch-up tube with one end extending out of the box is provided on the upper side of the wire passing hole.

[0012] In the aforementioned device, the first chamber and the fourth chamber are both provided with a power compensation mechanism, which is used to provide rotation assistance to the upper guide wheel or the lower guide wheel to reduce the movement resistance of the copper flat wire on the upper guide wheel or the lower guide wheel.

[0013] In the aforementioned device, the power compensation mechanism includes a first bracket plate and a second bracket plate both fixed to the box body, the first bracket plate and the second bracket plate are parallel to each other, a plurality of rotating shafts are provided between the first bracket plate and the second bracket plate, one end of the rotating shaft extends out of the first bracket plate and is connected to the upper guide wheel or the lower guide wheel, a pulley mechanism is provided between adjacent rotating shafts, and a motor with an output end connected to one of the rotating shafts is provided on the second bracket plate.

[0014] In the aforementioned device, the rotating shaft is connected to the upper guide wheel or the lower guide wheel bearing, and a magnetic disk close to the upper guide wheel or the lower guide wheel is provided at the end of the rotating shaft. The magnetic disk is threadedly connected to the rotating shaft, and a nut connected to the rotating shaft is provided on one side of the magnetic disk.

[0015] Compared with the prior art, the present invention first uses high-solid paint for painting, which increases the paint solute of a single painting and increases the paint film thickness of a single painting, thereby reducing the number of painting times and reducing the length of the production line, which is beneficial to site layout. Moreover, during drying, the copper flat wire basically maintains vertical movement, parallel to the direction of gravity, to avoid paint concentration on one side of the copper flat wire, so that the paint film is uniform, thereby improving the yield of the enameled wire.

[0016] The device of the present invention has a plurality of guide wheels, so that the copper flat wire can be bent back and forth vertically to pass through the cabinet, and can be painted and dried multiple times in the process of passing back and forth. The length of the device can be reduced by increasing the height of the device, thereby reducing the length of the production line, which is beneficial to site layout. After each painting, the copper flat wire first enters the second chamber with a lower temperature, then enters the third chamber with a higher temperature, and finally leaves the second chamber with a lower temperature. This can not only improve the quality of the paint film and the yield of the enameled wire, but also reduce energy consumption losses. By providing a power compensation mechanism to give the guide wheel an assist, sliding friction between the enameled wire and the guide wheel can be avoided, and the paint film can be prevented from being scratched, which also improves the yield of the enameled wire.

[0017] Therefore, the present invention has the advantages of reducing the length of the production line, improving the yield of the enameled wire and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view schematic diagram of the present invention.

[0019] Figure 2 is a schematic diagram of a painting device.

[0020] Figure 3 It is a top view schematic diagram of the power compensation mechanism at the lower guide wheel.

[0021] The marks in the accompanying drawings are: 1-copper flat wire, 2-box, 3-first chamber, 4-second chamber, 5-third chamber, 6-fourth chamber, 7-smoke exhaust pipe, 8-upper guide wheel, 9-lower guide wheel, 10-heater, 11-painting device, 12-dehumidification duct, 13-first fan, 14-dehumidification filter, 15-first air inlet, 16-second fan, 17-second air inlet, 18-overflow paint box, 19-painting block, 20-wire hole, 21-paint touch-up tube, 22-first bracket plate, 23-second bracket plate, 24-rotating shaft, 25-pulley mechanism, 26-motor, 27-disk, 28-nut. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0023] Embodiment 1. The process of painting enameled copper flat wires is to bend the moving route of the copper flat wire 1 on the production line to form four U-shaped channels, and the N channels are connected in series. From the moving direction of the copper flat wire 1, the enameled wire first moves downward into the channel, and then moves upward to leave the channel. At the starting points of the second to third channels, paint with a solid content of 35%-45% is applied to the copper flat wire 1, and at the starting point of the fourth channel, paint with a solid content of 25%-30% is applied to the copper flat wire 1, and the paint is dried at the channel.

[0024] The paint is polyimide paint, which is first heated in the channel at a temperature of 180-240° C. (preferably 220° C.) for more than 15 seconds, and then heated at a temperature of 350-400° C. for more than 30 seconds.

[0025] Embodiment 2. A device for implementing the enameled copper flat wire varnishing process of embodiment 1 is used in series in an enameled wire production line, comprising a box body 2, in which a first chamber 3, a second chamber 4, a third chamber 5 and a fourth chamber 6 are arranged from top to bottom, a smoke exhaust pipe 7 is arranged on the top of the first chamber 3, five horizontally distributed upper guide wheels 8 are arranged in the first chamber 3, four horizontally distributed lower guide wheels 9 are arranged in the fourth chamber 6, and heaters 10 are arranged in both the second chamber 4 and the third chamber 5.

[0026] The heater 10 has a constant temperature heating function. It is an existing product. The heating temperature of the heater 10 in the second chamber 4 is set to 220°C, and the heating temperature of the heater 10 in the third chamber 5 is set to 350-400°C, preferably 370°C.

[0027] The copper flat wire 1 enters the first chamber 3, alternately bypasses the upper guide wheel 8 and the lower guide wheel 9, and then leaves the first chamber 3. Holes for the copper flat wire 1 to pass through need to be set on the first chamber 3 and between each chamber. The gap between the hole and the copper flat wire 1 is about 3mm, and the hole also has the function of discharging the exhaust gas upward.

[0028] Three painting devices 11 are arranged in the first chamber 3 , and the three painting devices 11 are respectively located below the outlet side of the second to third upper guide wheels 8 .

[0029] A dehumidification pipe 12 is provided on the outside of the box body 2, and both ends of the dehumidification pipe 12 are connected to the second chamber 4. The dehumidification pipe 12 is provided with a first fan 13 and a dehumidification filter 14. The dehumidification filter 14 can be purchased directly or made by yourself, such as taking a sealed box in series to the dehumidification pipe 12, and placing limestone filled in a non-woven bag in the sealed box.

[0030] The first chamber 3 is provided with a first air inlet 15, the smoke exhaust pipe 7 is provided with a second fan 16, and the fourth chamber 6 is provided with a second air inlet 17. Under the transpiration effect, clean cold air from the outside world enters the fourth chamber 6 from the second air inlet 17 at a low flow rate, and then enters the third chamber 5, the high-heat exhaust gas in the third chamber 5 enters the second chamber 4, and the high-heat exhaust gas in the second chamber 4 enters the first chamber 3. Under the action of the second fan 16, the cold air from the outside world enters the first chamber 3 from the first air inlet 15 at a high speed and mixes with the high-heat exhaust gas. After cooling, it is discharged from the smoke exhaust pipe 7, and it needs to be connected to the exhaust gas treatment device before it can be discharged into the atmosphere.

[0031] The painting device 11 includes a paint overflow box 18 with an opening at the top, a paint block 19 is provided in the middle of the paint overflow box 18, a wire hole 20 is vertically provided in the paint block 19, the upper and lower ends of the wire hole 20 are both bell mouths, the middle of the wire hole 20 shrinks inward to form a wire hole that matches the copper flat wire 1, and a paint touch-up tube 21 with one end extending out of the box 2 is provided on the upper side of the wire hole 20, and the paint touch-up tube 21 is connected to a paint source, such as a paint pool storing paint, through an oil pump. The paint touch-up tube 21 outputs paint to the copper flat wire 1 at a constant speed, and evenly applies the paint to the copper flat wire 1 through the bell mouth at the wire hole 20.

[0032] The first chamber 3 and the fourth chamber 6 are both provided with a power compensation mechanism, which is used to provide rotation assistance to the upper guide wheel 8 or the lower guide wheel 9 to reduce the movement resistance of the copper flat wire 1 on the upper guide wheel 8 or the lower guide wheel 9.

[0033] The power compensation mechanism includes a first bracket plate 22 and a second bracket plate 23 both fixed to the box body 2, the first bracket plate 22 and the second bracket plate 23 are parallel to each other, a plurality of rotating shafts 24 are arranged between the first bracket plate 22 and the second bracket plate 23, one end of the rotating shaft 24 extends out of the first bracket plate 22 and is connected to the upper guide wheel 8 or the lower guide wheel 9, a pulley mechanism 25 is arranged between adjacent rotating shafts 24, and a motor 26 whose output end is connected to one of the rotating shafts 24 is arranged on the second bracket plate 23. The pulley mechanism 25 includes synchronous wheels respectively connected to two adjacent rotating shafts 24 and a synchronous belt connected between the two synchronous wheels.

[0034] The rotating shaft 24 is connected to the upper guide wheel 8 or the lower guide wheel 9 by a bearing. A magnetic disk 27 close to the upper guide wheel 8 or the lower guide wheel 9 is provided at the end of the rotating shaft 24 . The magnetic disk 27 is screwed to the rotating shaft 24 . A nut 28 connected to the rotating shaft 24 is provided on one side of the magnetic disk 27 .

[0035] Working principle: The copper flat wire 1 is bent into a U-shape by the lower guide wheel 9 between two adjacent upper guide wheels 8, that is, the bending part of each U-shaped channel corresponds to the lower guide wheel 9.

[0036] The copper flat wire 1 is heated when passing through the first channel, and the surface moisture is dried, so that the subsequent paint film has good bonding strength.

[0037] When the copper flat wire 1 passes through the second and third channels, it is first painted by the painting device 11 in the first chamber 3, and then enters the second chamber 4 for the first heating. The temperature of the first heating is 220°C. The paint undergoes a cross-linking reaction at a relatively low temperature and a slow curing speed, ensuring that the volume can be smoothly discharged from the paint layer after vaporization, and bubbles are avoided in the paint film while applying a thicker paint film. Then, it enters the third chamber 5 for the second heating. The temperature of the second heating is 370°C (which is also the paint curing temperature in the prior art). The paint undergoes a cross-linking reaction at a relatively high temperature, which can improve the quality of the paint film. Then, it returns to the second chamber 4, and the cured paint is cooled with a relatively low temperature difference in the second chamber 4, which reduces stress accumulation and improves the crack resistance of the paint film. At the same time, part of the heat is recovered to the second chamber 4, which reduces energy consumption. Finally, it enters the first chamber 3, and after cooling to below 120°C in the first chamber 3, it is painted again at the painting device 11. When painting again, due to the relatively low temperature of the copper flat wire 1, the paint curing and granulation in the painting device 11 is reduced and can be evenly coated, thereby improving the quality of painting. The solid content of the paint applied to the copper flat wire 1 when it passes through the second and third passages is 35%-45%.

[0038] The solid content of the paint applied to the copper flat wire 1 when it passes through the fourth channel is 25%-30%.

[0039] The thickness of the paint applied to the copper flat wire 1 when passing through the second and third channels is greater than the thickness of the paint applied when passing through the fourth channel, for example, the thickness of the first two paints is 15 microns, and the third paint is 8 microns. The first two paints use high-solid paint to form a thicker paint film, and the last paint uses low-solid paint with high fluidity to ensure a smooth outer periphery of the paint film.

[0040] The first fan 13 circulates the air in the second chamber 4 through the dehumidification filter 14, ensuring that the air humidity in the second chamber 4 is low, thereby improving the painting quality.

[0041] In the power compensation mechanism, since there is a pulley mechanism between each rotating shaft 24, the motor 26 drives the rotating shaft 24 to rotate synchronously, and the rotating shaft 24 drives the magnetic disk 27 to rotate. Assuming that the total rotation resistance of all lower guide wheels 9 and upper guide wheels 8 is F under normal circumstances, by adjusting the distance between each magnetic disk 27 and the lower guide wheel 9 or the upper guide wheel 8, the two power compensation mechanisms can provide a total of 0.7F-0.95F of assistance to all lower guide wheels 9 and upper guide wheels 8. In this way, the copper flat wire 1 cannot be driven to move by the power compensation mechanism alone. The movement of the copper flat wire 1 still requires a small amount of traction from the production line to ensure that the rotation speed of the lower guide wheel 9 and the upper guide wheel 8 matches the movement speed of the copper flat wire 1, avoiding sliding friction and preventing damage to the paint film. At the same time, the longitudinal resistance of the copper flat wire 1 is small, which prevents the surface paint film from having friction wrinkles due to excessive traction resistance. The power compensation mechanism has a simple structure and a relatively low implementation cost.

Claims

1. Enameled copper flat wire varnishing process, characterized by: The moving route of the copper flat wire (1) on the production line is bent to form N U-shaped channels, and the N channels are connected in series. From the moving direction of the copper flat wire (1), the enameled wire first moves downward to enter the channel, and then moves upward to leave the channel. At the starting points of the second to N-1 channels, the copper flat wire (1) is painted with paint with a solid content of 35%-45%, and at the starting point of the Nth channel, the copper flat wire (1) is painted with paint with a solid content of 25%-30%, and the paint is dried at the channel.

2. The process for painting enameled flat copper wire according to claim 1, characterized in that: The paint is polyimide paint, which is first heated in the channel at a temperature of 180-240° C. for more than 15 seconds, and then heated at a temperature of 350-400° C. for more than 30 seconds.

3. A device for implementing the varnishing process for the enameled flat copper wire according to claim 1 or 2, characterized in that: The invention comprises a box body (2), wherein a first chamber (3), a second chamber (4), a third chamber (5) and a fourth chamber (6) are sequentially arranged in the box body (2) from top to bottom, a smoke exhaust pipe (7) is arranged at the top of the first chamber (3), N+1 horizontally distributed upper guide wheels (8) are arranged in the first chamber (3), N horizontally distributed lower guide wheels (9) are arranged in the fourth chamber (6), the second chamber (4) and the third chamber (5) are both provided with a heater (10), the copper flat wire (1) enters the first chamber (3), alternately bypasses the upper guide wheel (8) and the lower guide wheel (9), and then leaves the first chamber (3), the first chamber (3) is provided with N-1 painting devices (11), and the N-1 painting devices (11) are respectively located below the outlet side of the second to N-1 upper guide wheels (8).

4. The device according to claim 3, characterized in that: A dehumidification pipe (12) is provided on the outside of the box body (2), both ends of the dehumidification pipe (12) are connected to the second chamber (4), and a first fan (13) and a dehumidification filter (14) are provided on the dehumidification pipe (12).

5. The device according to claim 3, characterized in that: The first chamber (3) is provided with a first air inlet (15), the smoke exhaust pipe (7) is provided with a second fan (16), and the fourth chamber (6) is provided with a second air inlet (17).

6. The device according to claim 3, characterized in that: The painting device (11) comprises a paint overflow box (18) with an opening at the top, a paint block (19) is provided in the middle of the paint overflow box (18), a wire passing hole (20) is vertically provided on the paint block (19), the upper and lower ends of the wire passing hole (20) are both bell-shaped, the middle of the wire passing hole (20) shrinks inward to form a wire passing hole that matches the copper flat wire (1), and a paint touch-up tube (21) with one end extending out of the box (2) is provided on the upper side of the wire passing hole (20).

7. The device according to claim 3, characterized in that: The first chamber (3) and the fourth chamber (6) are both provided with a power compensation mechanism, which is used to provide rotation assistance to the upper guide wheel (8) or the lower guide wheel (9), thereby reducing the moving resistance of the copper flat wire (1) on the upper guide wheel (8) or the lower guide wheel (9).

8. The device according to claim 7, characterized in that: The power compensation mechanism comprises a first bracket plate (22) and a second bracket plate (23) both fixed to the box body (2); the first bracket plate (22) and the second bracket plate (23) are parallel to each other; a plurality of rotating shafts (24) are arranged between the first bracket plate (22) and the second bracket plate (23); one end of the rotating shaft (24) extends out of the first bracket plate (22) and is connected to an upper guide wheel (8) or a lower guide wheel (9); a pulley mechanism (25) is arranged between adjacent rotating shafts (24); and a motor (26) having an output end connected to one of the rotating shafts (24) is arranged on the second bracket plate (23).

9. The device according to claim 8, characterized in that: The rotating shaft (24) is connected to the upper guide wheel (8) or the lower guide wheel (9) by a bearing, and a magnetic disk (27) close to the upper guide wheel (8) or the lower guide wheel (9) is provided at the end of the rotating shaft (24), the magnetic disk (27) is screwed to the rotating shaft (24), and a nut (28) connected to the rotating shaft (24) is provided on one side of the magnetic disk (27).

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