A double-sided laser processing method

Abstract

The application discloses a double-sided laser processing method. It comprises setting a line scanning camera corresponding to a programmable uniform light processing head on the front surface of a strip and a programmable uniform light processing head corresponding to the back surface of the strip. The line scanning camera is used to detect the laser processing pixel position on the front surface of the strip and send the detected laser processing pixel position data on the front surface to a control unit. After processing the laser processing pixel position data on the front surface, the control unit calculates the laser processing pixel position of the processing area on the back surface of the strip and moves to the processing position of the processing head corresponding to the back surface of the programmable uniform light processing head on the starting position of the processing area on the front surface. Then, the laser processing is carried out according to the laser processing pixel position on the back surface of the strip. The application realizes the complete coincidence of the processing positions on the front and back surfaces of the strip, guarantees the precision of the laser processing, adjusts the interval length corresponding to the last processing pixel dynamically, guarantees the relative uniformity of the processing interval and the absolute position precision of the last processing position.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser processing, in particular to a double-sided laser processing method. BACKGROUND

[0002] In the traditional lithium ion battery manufacturing process, the drying and modification of electrode materials are particularly critical. The process requires the use of a large amount of chemical solution and high temperature and high pressure conditions, and the processing result directly affects the performance and service life of the battery. Traditional electrode processing technologies, such as hot air convection drying, infrared drying and microwave drying, often have low drying efficiency, unstable product quality, high energy consumption and complex process, etc. The local modification of the electrode sheet requires high precision and processing efficiency, and the traditional processing method cannot meet the requirements of precision and efficiency. These technologies can be realized by laser processing to achieve more accurate manufacturing, thereby reducing the use of chemical solution and energy consumption in the manufacturing process, and also improving the energy density and cycle life of the battery. SUMMARY

[0003] The present application aims to solve the problems existing in the prior art and provides a double-sided laser processing method.

[0004] To achieve the above-mentioned purpose, the present application provides a double-sided laser processing method, comprising:

[0005] According to the processing requirements of the strip material, a plurality of programmable uniform light processing heads are arranged side by side on the front and back of the strip material, so that the laser processing areas of the corresponding programmable uniform light processing heads on the front and back of the strip material respectively cover the required processing positions on the front and back of the strip material. The programmable uniform light processing head on the front of the strip material is arranged on the front side of the programmable uniform light processing head on the back of the strip material.

[0006] According to the processing requirements of the strip material, the laser parameters of each programmable uniform light processing head are set to match the heating process of the processing area on the strip material with the processing requirements of the strip material.

[0007] A roll-to-roll take-up and release mechanism is used to control the movement of the strip material along the length direction, and an encoder is arranged on the over-roller shaft of the roll-to-roll take-up and release mechanism to obtain the movement signal of the strip material. During the movement of the strip material, a position sensor is used to identify the processing area on the front of the strip material, and based on the distance between the position sensor and the programmable uniform light processing head and the movement signal obtained by the encoder, the positional relationship between the start and end positions of the processing area on the front and the positions of the programmable uniform light processing heads is determined. When the start position of the processing area on the front moves to the processing position of the corresponding programmable uniform light processing head, the corresponding programmable uniform light processing head is controlled to perform laser processing on the processing area on the front. When the end position of the processing area on the front moves to the processing position of the corresponding programmable uniform light processing head, the laser processing is stopped.

[0008] A line scan camera is arranged on the programmable uniform light processing head corresponding to the front surface of the strip material and on the programmable uniform light processing head corresponding to the back surface of the strip material, which is used to detect the laser processing pixel position of the front surface of the strip material and send the detected laser processing pixel position data of the front surface to the control unit. After the control unit processes the laser processing pixel position data of the front surface, the laser processing pixel position of the processing area of the back surface of the strip material is calculated, and when the starting position of the processing area of the front surface moves to the processing position of the programmable uniform light processing head corresponding to the back surface, laser processing is performed according to the laser processing pixel position of the back surface of the strip material, so that the processing positions of the front and back surfaces of the strip material correspond one by one.

[0009] Further, during the processing of the processing area of the front surface of the strip material, the control unit also calculates the length of the remaining processing area in real time and adjusts the last processing pixel position according to the length of the remaining processing area.

[0010] Further, the last processing pixel position is adjusted according to the length of the remaining processing area as follows:

[0011] If the remaining processing length L is greater than (m+j), the last processing pixel is normally processed by laser according to the set interval length j, where m is the size of one processing pixel of the programmable uniform light processing head along the length direction of the strip material;

[0012] If the remaining processing length L is less than (m+j) and greater than (m+j) / 2, the last processing pixel is processed by laser at a distance of (m+j) / 2 from the end processing position;

[0013] If the remaining processing length L is less than ((m+j)) / 2, the laser processing is stopped.

[0014] Further, the control unit includes a plurality of control devices, each control device controls the operation of one programmable uniform light processing head, one of the plurality of control devices is a master control device, and the rest are slave control devices. The master control device receives the signal collected by the position sensor and processes the signal collected by the position sensor, and then outputs a trigger synchronization signal with a fixed pulse width to the slave control devices.

[0015] Further, the movement signal obtained by the encoder is connected to all control devices after signal enhancement processing and division, the master control device processes the movement signal obtained by the encoder, and outputs a position synchronization pulse signal to the slave control devices according to the fixed interval distance of the strip material movement, and the slave control devices forcibly synchronize the encoder counting after receiving the position synchronization pulse signal.

[0016] Further, the position sensor is an optical sensor or a color mark sensor.

[0017] Further, the plurality of programmable homogenization processing heads are respectively fixed on linear motors of the plurality of movers corresponding to the front and back surfaces of the strip.

[0018] Beneficial effects: the present application detects the actual processing position of the front surface of the strip by the line scanning camera, controls the laser to perform online laser heating processing on the designated processing area of the front surface of the strip according to the preset interval distance, sends the actual processing position of the front surface of the strip detected by the line scanning camera to the control device, calculates the processing position of the back surface of the strip after data processing by the control device, controls the laser to perform online laser heating processing on the back surface of the strip, realizes the complete coincidence of the processing positions of the front and back surfaces of the strip, and guarantees the precision of the laser processing; the present application dynamically adjusts the interval length corresponding to the last processing element, guarantees the relative uniformity of the processing interval, and guarantees the absolute position precision of the last processing position; the present application realizes more precise heating manufacturing by laser processing, has high processing efficiency, high precision, high processing quality, and low energy consumption, and effectively solves the shortcomings of the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the device structure schematic diagram of the double-sided laser processing method of the embodiment of the present application;

[0020] Figure 2 is the schematic diagram of the laser processing element of the embodiment of the present application. DETAILED DESCRIPTION

[0021] The present application will be further illustrated in combination with the drawings and specific embodiments, the embodiments are implemented on the premise of the technical scheme of the present application, and it should be understood that the embodiments are only used for illustrating the present application and are not used for limiting the scope of the present application.

[0022] The embodiment of the present application provides a double-sided laser processing method, which comprises:

[0023] Referring to Figure 1According to the processing requirement of the strip material 220, a plurality of programmable uniform light processing heads 230 are arranged side by side on the front and back surfaces of the strip material 220, so that the laser processing areas of the corresponding programmable uniform light processing heads 230 on the front and back surfaces of the strip material 220 respectively splice and cover the required processing positions on the front and back surfaces of the strip material 220. The programmable uniform light processing head 230 corresponding to the front surface of the strip material 220 is arranged on the front side of the programmable uniform light processing head 230 corresponding to the back surface of the strip material 220. The plurality of programmable uniform light processing heads 230 can be respectively fixed on the linear motors corresponding to the front and back surfaces of the strip material 220. The programmable uniform light processing head 230 can move with the linear motor, and the position of the linear motor can be adjusted according to the processing requirement of the strip material 220 and the processing range of the single programmable uniform light processing head 230, so that the processing area spliced by the programmable uniform light processing head 230 covers the required processing position of the strip material 220. Specifically, the processing area of each programmable uniform light processing head 230 is a line segment, and the processing areas of the plurality of programmable uniform light processing heads 230 can be spliced into a longer line segment, and the direction of the line segment is arranged along the width direction of the strip material 220, thereby covering the required processing position of the strip material 220. The number of programmable uniform light processing heads 230 is preferably a plurality, and the corresponding number can be set according to the width of the processing area on the strip material 220, or the number can be set to meet the width of the maximum processing area. When processing the processing area with a smaller width, the corresponding number of programmable uniform light processing heads 230 can be controlled to work.

[0024] The programmable uniform light processing head 230 is composed of a plurality of independent laser unit module arrays. Each laser unit module can not only accurately control and quickly switch the output power of the laser, but also can arbitrarily program the laser processing area of the processing head by controlling each independent laser unit module, so that the energy of the laser in the laser processing area output by the processing head is uniformly distributed.

[0025] According to the processing requirement of the strip material 220, the laser parameters of each programmable uniform light processing head are set to match the heating process of the processing area on the strip material 220 with the processing requirement of the strip material 220. The above-mentioned laser parameters include the laser processing primitive size, interval length, light point position of the array laser unit module in the single programmable uniform light processing head 230, and the laser output energy of each programmable uniform light processing head 230 in the processing area of one strip material 220. Specifically, the size and interval length of the laser processing primitive are set by the control unit, the length and interval length of each laser processing primitive are accurately controlled by the position feedback of the encoder 310, the laser processing area of the programmable uniform light processing head is set by controlling each independent laser unit module in the single programmable uniform light processing head 230, and the laser output power of each programmable uniform light processing head 230 is set, so that the same or different temperature partitions required by the processing requirement of the strip material 220 can be formed in the whole processing area.

[0026] The length direction movement of the strip 220 is controlled by a roll-to-roll take-up and pay-off mechanism, which specifically includes a pay-off roll 100, a plurality of over-rolls 110, and a take-up roll 120. An encoder 310 is arranged on the roll shaft of the over-rolls 110 of the roll-to-roll take-up and pay-off mechanism, and is used to obtain a movement signal of the strip 220. During the movement of the strip 220, a position sensor 210 is used to identify the processing area of the front surface of the strip 220, and based on the spacing between the position sensor 210 and the corresponding programmable uniform light processing head 230, and the movement signal obtained by the encoder 310, the positional relationship between the start position and the end position of the processing area of the front surface and the corresponding programmable uniform light processing head 230 is determined. When the start position of the processing area of the front surface moves to the processing position of the corresponding programmable uniform light processing head 230, the corresponding programmable uniform light processing head 230 is controlled to perform laser processing on the processing area of the front surface. When the end position of the processing area of the front surface moves to the processing position of the corresponding programmable uniform light processing head 230, the laser processing is stopped. Two position sensors 210 are arranged in front of the corresponding programmable uniform light processing head 230, one of which is used to detect the start position of the processing area, and the other is used to detect the end position of the processing area.

[0027] The above-mentioned encoder 310 is preferably an incremental encoder, which is a kind of displacement transducer that converts displacement into a periodic electrical signal, and then converts the electrical signal into counting pulses, and uses the number of pulses to represent the size of displacement. It directly uses the principle of photoelectric conversion to output three groups of square wave pulses A, B and Z phase. The phase difference between the two groups of A and B pulses is 90 degrees, so that the rotation direction can be easily determined. The Z phase is used to mark the starting position of each circle of the encoder 310, and is used to mark the starting position of each circle of the encoder 310. The encoder 310 is used to determine the processing position of the processing area on the strip 220 into and out of the plurality of programmable uniform light processing heads 230 in combination with the position sensor 210, and to provide a basis for the opening of the laser and the adjustment of the laser processing distance. Specifically, when the position sensor 210 detects the starting position of the processing area, the current value of the encoder 310 is recorded. When the change amount of the value of the encoder 310 reaches the target change amount set according to the distance between the encoder 310 and the programmable uniform light processing head 230 in the direction of the strip 220, it is determined that the processing area has moved to the processing position of the plurality of programmable uniform light processing heads. After installation, the distance between the position sensor 210 and the programmable uniform light processing head 230 in the direction of the strip 220 is fixed, and the movement of the strip 220 from the position sensor 210 to the processing position of the programmable uniform light processing head 230 is also fixed. The angle of rotation of the roller shaft of the roller 110 installed during the movement of the encoder 310 is also fixed, and the change amount of the value of the encoder 310 during the movement is also fixed. After setting the target change amount during the debugging stage, when the position sensor 210 detects the starting position of the processing area, the change amount of the value of the encoder 310 reaches the set target change amount, and the starting position of the processing area is located at the processing position of the programmable uniform light processing head. At this time, the control emits a laser, and the laser processing can be performed from the starting position of the processing area. In addition, when the length of the processing area on the strip 220 is less than the distance between the position sensor 210 and the programmable uniform light processing head 230 in the direction of the strip 220, it is necessary to trigger the latch of the position sensor 210 to record the values of the encoder 310 corresponding to the starting position and the ending position of two or more processing areas, and to sequentially perform laser processing according to the change amount of the value of the encoder 310.

[0028] The line scan camera 240 is arranged between the programmable uniform light processing head 230 corresponding to the front surface of the strip 220 and the programmable uniform light processing head 230 corresponding to the back surface of the strip 220, and is used to detect the laser processing element position on the front surface of the strip 220 and send the detected laser processing element position data on the front surface to the control unit. After the control unit processes the laser processing element position data on the front surface, the laser processing element position on the processing area on the back surface of the strip 220 is calculated. A position sensor 210 is also arranged between the line scan camera 240 and the programmable uniform light processing head 230 corresponding to the back surface, and is used to detect the starting position of the processing area on the front surface. The starting position of the processing area on the front surface and the position of the programmable uniform light processing head 230 corresponding to the back surface are determined by the distance between the position sensor 210 and the programmable uniform light processing head 230 corresponding to the back surface, and the movement signal obtained by the encoder 310. When the starting position of the processing area on the front surface moves to the processing position of the programmable uniform light processing head 230 corresponding to the back surface, laser processing is performed according to the laser processing element position on the back surface of the strip 220, so that the processing positions on the front and back surfaces of the strip 220 are one-to-one corresponding, and the precision of the laser processing is ensured. During the processing of the processing area on the front surface of the strip 220, the control unit also calculates the length of the remaining processing area in real time, and adjusts the last processing element position according to the length of the remaining processing area. The specific method is as follows:

[0029] If the remaining processing length L is greater than (m+j), the last processing element normally performs laser processing according to the set interval length j, where m is the size of one processing element of the programmable uniform light processing head 230 along the length direction of the strip. Figure 2 The entire gray area in the above-mentioned laser processing element along the length direction of the strip m and the interval length j are as shown in Figure 2

[0030] If the remaining processing length L is less than (m+j) and greater than (m+j) / 2, the last processing element performs laser processing at a distance of (m+j) / 2 from the end processing position.

[0031] If the remaining processing length L is less than ((m+j)) / 2, the laser processing is stopped.

[0032] ​The control unit of the embodiment of the present application comprises a plurality of control devices, each of which controls the operation of one programmable uniform light processing head 230. Since the present application adopts the mode of synchronous online flight splicing processing of a plurality of programmable uniform light processing heads 230, there is a deviation between the processing of external trigger signals and the counting of the encoder 310, the high-level pulse width of the position sensor 210 signal changes with the speed of the strip 220 movement, the faster the strip speed, the shorter the high-level pulse width of the position sensor 210 signal, and the position sensor 210 signal and the encoder 310 signal are easily disturbed by the clutter signals on the line. In order to ensure the accuracy of the flight splicing, one of the plurality of control devices is the master control device, and the others are slave control devices. The master control device receives the signal collected by the position sensor 210 and processes the signal collected by the position sensor 210, including filtering and synchronization processing, and then outputs a fixed pulse width trigger synchronization signal to the slave control device. The movement signal obtained by the encoder 310 is connected to all control devices after signal enhancement processing and division. After the master control device processes the movement signal obtained by the encoder 310, it outputs a position synchronization pulse signal to the slave control device according to the fixed interval distance of the strip 220 movement. After the slave control device receives the position synchronization pulse signal, it forces the encoder 310 to count. The master-slave control device synchronizes the strip movement position obtained by the encoder counting, thereby avoiding the misalignment of the splicing position. The above-mentioned signal enhancement processing is a signal processing method, which refers to enhancing the driving ability of the signal without changing the characteristics of the original signal, so as to enhance the signal strength and reduce the attenuation problem caused by splitting.

[0033] In addition, it should be noted that the processing area on the strip 220 can be a plurality of spaced apart, i.e. the two adjacent processing areas are separated by a non-processing area. The above-mentioned processing area needs to be marked in advance and identified by the position sensor 210 before entering the processing position of the programmable uniform light processing head 230. The above-mentioned position sensor 210 needs to be arranged opposite to the strip. Taking the production of lithium battery electrodes as an example, the processing area and the non-processing area on the strip 220 are arranged to be different materials, and the color and reflectivity of the two materials are different, so they can be identified by the photoelectric sensor or color marker sensor arranged on the front side of the programmable uniform light processing head opposite to the front and back of the strip 220.

[0034] The above-mentioned only is the preferred embodiment of the present application, it should be noted that for ordinary skilled in the art, other not specifically described part, belongs to the prior art or common knowledge. Without departing from the principles of the present application, a number of improvements and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A double-sided laser processing method, characterized by, The application relates to a laser processing device for processing a strip material, which comprises the following parts: According to the processing requirements of the strip material, a plurality of programmable uniform light processing heads are arranged on the front and back surfaces of the strip material respectively, so that the laser processing areas of the programmable uniform light processing heads on the front and back surfaces of the strip material respectively splice and cover the required processing positions on the front and back surfaces of the strip material, and the programmable uniform light processing head on the front surface of the strip material is arranged on the front side of the programmable uniform light processing head on the back surface of the strip material; According to the processing requirements of the strip material, the laser parameters of each programmable uniform light processing head are set, so that the heating process of the processing area on the strip material matches the processing requirements of the strip material; The strip material is controlled to move along the length direction by using a roll-to-roll take-up and pay-off mechanism, and an encoder is arranged on the over-roller shaft of the roll-to-roll take-up and pay-off mechanism to obtain the moving signal of the strip material; during the movement of the strip material, a position sensor is used to identify the processing area on the front surface of the strip material, and the positional relationship between the starting position and the ending position of the processing area on the front surface and the programmable uniform light processing head is judged based on the distance between the position sensor and the programmable uniform light processing head and the moving signal obtained by the encoder; when the starting position of the processing area on the front surface moves to the processing position of the corresponding programmable uniform light processing head, the corresponding programmable uniform light processing head is controlled to perform laser processing on the processing area on the front surface; when the ending position of the processing area on the front surface moves to the processing position of the corresponding programmable uniform light processing head, the laser processing is stopped; A line scanning camera is arranged on the programmable uniform light processing head corresponding to the front surface of the strip material and the programmable uniform light processing head corresponding to the back surface of the strip material, the line scanning camera is used to detect the laser processing pixel position on the front surface of the strip material and send the detected laser processing pixel position data on the front surface to a control unit, the control unit processes the laser processing pixel position data on the front surface, calculates the laser processing pixel position of the processing area on the back surface of the strip material, and performs laser processing according to the laser processing pixel position on the back surface of the strip material when the starting position of the processing area on the front surface moves to the processing position of the programmable uniform light processing head corresponding to the back surface, so that the processing positions on the front and back surfaces of the strip material correspond to each other one by one; During the processing of the processing area on the front surface of the strip material, the control unit also calculates the length of the remaining processing area in real time and adjusts the last processing pixel position according to the length of the remaining processing area.

2. The double-sided laser processing method according to claim 1, wherein The way of adjusting the last processing pixel position according to the length of the remaining processing area is as follows: If the remaining processing length L is greater than (m+j), the last processing pixel normally performs laser processing according to the set interval length j, wherein m is the size of one processing pixel of the programmable uniform light processing head along the length direction of the strip material; If the remaining processing length L is less than (m+j) and greater than (m+j) / 2, the last processing pixel performs laser processing at a distance of (m+j) / 2 from the ending processing position; If the remaining processing length L is less than ((m+j)) / 2, the laser processing is stopped.

3. The method of claim 1, wherein the laser beam is split into two beams. The control unit comprises a plurality of control devices, each of which controls a programmable uniform light processing head, one of the plurality of control devices is a master control device, and the rest are slave control devices, the master control device receives signals collected by a position sensor, processes the signals collected by the position sensor, and then outputs a trigger synchronization signal with a fixed pulse width to the slave control devices.

4. A double-sided laser processing method according to claim 3, wherein The mobile signals obtained by the encoder are processed by signal enhancement and then divided and connected to all the control devices, the master control device processes the mobile signals obtained by the encoder, and then outputs a position synchronization pulse signal to the slave control devices at a fixed interval distance according to the strip movement, and the slave control devices are forced to synchronize the encoder counting after receiving the position synchronization pulse signal.

5. The method of claim 1, wherein the laser beam is a pulsed laser beam. The position sensor is an optical sensor or a color mark sensor.

6. The method of claim 1, wherein, A plurality of programmable uniform light processing heads are respectively fixed on linear motors corresponding to the positive and negative sides of the strip.

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