A vehicle-mounted three-beam laser welding machine

Abstract

A vehicle-mounted three-beam laser welding machine, the laser module includes a laser synchronization control unit and multiple laser output units; the laser synchronization control unit is used to control the light output and data collection of each laser output unit; the laser output unit is used to generate and output laser; the power supply module is used to power the laser module, the cooling module, and the electrical equipment in the central control module; the cooling module is used to cool the laser module and the power supply module; the central control module is electrically connected to the laser module, the cooling module, and the power supply module respectively, and the central control module is used for system information collection, information interaction, laser module light output control, and temperature control functions. The central control module is externally connected to a human-machine interaction interface, and information is exchanged with external devices through the human-machine interaction interface. This vehicle-mounted three-beam laser synchronization welding machine can be widely used in the coupling and welding of multi-core optical fibers, and provides an advanced vehicle-mounted practical tool for the coupling connection of seven-core optical fibers.

Description

Technical Field

[0001] The invention relates to the field of laser welding machines, and in particular to a vehicle-mounted three-beam laser welding machine. Background Art

[0002] At present, the rapid rise of mobile Internet, big data, cloud computing, and VR / AR has brought huge challenges to information and communication networks due to the surge in traffic. With the development of science and technology, the speed of traffic surge will definitely exceed the growth rate of optical network transmission capacity, and the growth rate of optical network capacity expansion will be one of the goals of the construction of the next generation of networks. Multi-core optical fiber based on space division multiplexing technology is considered to be the key to solving the current system capacity limitations and building the next generation of optical communication networks. Unlike traditional single-core optical fiber, multi-core optical fiber has n cores distributed in the cladding of the same optical fiber. Obviously, for the same optical fiber, the transmission capacity of multi-core optical fiber has increased by n times. The practical seven-core optical fiber that has been developed is 7 times the transmission rate of traditional optical fiber. As the carrier of the new generation of optical network architecture, it has been a hot spot in optical communication in recent years. The application of seven-core optical fiber must solve the fusion or coupling of optical fibers before it can enter engineering practice. At present, the fusion splicing of seven-core optical fibers can only be achieved in ultra-clean space with expensive optical fiber fusion splicers, which has caused great difficulties in laying optical fiber networks. The laying of optical networks, especially trunk optical networks, is mostly done in the field without laboratory environment conditions. The working point is highly mobile, the ambient temperature and humidity cannot be guaranteed, and there is often a lot of dust. Even if a clean and stable engineering vehicle can be used, the expensive fiber fusion splicer needs to ensure the coupling and fusion of seven cores in one optical fiber, and the equipment with complex structure is not suitable for long-term stable use in a bumpy mobile environment. Moreover, according to the structural characteristics of multi-core optical fibers, if the method of direct spatial alignment is used to achieve optical coupling, a large coupling loss will be generated during the coupling process. Therefore, multi-core optical fibers mostly use the low-loss and economical optical fiber fan-in and fan-out device coupling welding solution to achieve high-efficiency optical coupling of multi-core optical fibers. Compared with the method of direct spatial alignment, the use of fan-in and fan-out devices to optically couple multi-core optical fibers can obtain higher coupling efficiency and lower coupling loss. Moreover, the simultaneous coupling and fusion of one fiber and seven cores is converted into 7 single-fiber single-core optical fiber fan-in and fan-out devices, which are independently coupled, which is convenient for field operation under complex conditions and realizes the engineering application of multi-core optical fiber cables in communication trunk lines. To achieve the low insertion loss and high efficiency coupling effect of the seven-core optical fiber connection through the technical solution of coupling the seven-core optical fiber through the fan-in and fan-out device, the most practical method is the coupling laser welding technology similar to the optoelectronic TO package tube shell. The single single-mode optical fiber (SMF) at the coupling end of the fan-in and fan-out device is encapsulated in the center of a stainless steel cylinder with a diameter of less than 3mm. After coupling and alignment, three-beam lasers are used to synchronously weld the coupled stainless steel cylinders together. The difficulty of simultaneously coupling and welding 7 fiber cores of a seven-core optical fiber with a diameter of less than 200um is converted into the relatively easy coupling and welding of a single-core optical fiber. The three-beam laser synchronous welding machine is the key equipment in the coupling welding process. Since the seven-core optical fiber needs to be operated at the engineering site, and the engineering site is highly mobile.Although there are lamp-pumped YAG lasers on the market that can be split into three laser beams for synchronous welding, the electro-optical conversion efficiency of lamp-pumped YAG lasers is low, only 3%, and the lamp pump is a consumable and needs to be replaced frequently, resulting in increased production and maintenance costs for YAG spot welding machines. In addition, YAG lasers are particularly sensitive to vibrations and are relatively large in size, making them unsuitable for mobile operations in the field. Summary of the invention

[0003] In order to enable the coupling and welding of multi-core optical fibers, especially the coupling and welding of seven-core optical fibers commonly used at present, the present invention adopts the following technical solutions:

[0004] A vehicle-mounted three-beam laser welding machine, comprising a laser module, a cooling module, a power supply module, and a central control module;

[0005] The laser module includes a laser synchronization control unit and a plurality of laser output units electrically connected to the laser synchronization control unit; the laser synchronization control unit is used to control the light output and data collection of each laser output unit; the laser output unit is used to generate and output laser;

[0006] The power supply module is used to supply power to the laser module, the cooling module, and the electrical equipment in the central control module;

[0007] The cooling module is used to cool the laser module and the power supply module;

[0008] The central control module is electrically connected to the laser module, cooling module and power supply module respectively. The central control module is used for system information collection, information interaction, laser module light output control and temperature control functions. The central control module is externally connected to a human-computer interaction interface, and information is exchanged with external devices through the human-computer interaction interface.

[0009] Specifically, the laser output unit includes a constant current source driver connected to the laser synchronization control unit, a guide red semiconductor laser and an output optical power sensor; the constant current source driver is connected to the semiconductor pump laser, and the laser output by the guide red semiconductor laser and the semiconductor pump laser is combined through a fiber optic combiner and then connected to a low-loss laser spot welding head through an energy transmission optical cable equipped with a transmission connector.

[0010] The workpiece to be welded is placed on a rotating processing table, and multiple low-loss laser spot welding heads are evenly distributed around the workpiece to be welded. The laser synchronization control unit controls the low-loss laser spot welding heads.

[0011] Specifically, the laser synchronization control unit includes a laser driving circuit; the laser driving circuit is used to simultaneously control the semiconductor pump lasers in multiple laser output units to output lasers according to time-division pulses;

[0012] The process of time-division pulse laser output is as follows: setting the emission time of the time-division pulses of multiple laser synchronization control units, the output emission time is consistent, multiple laser output units simultaneously output a preliminary fixed pulse, and then the time-division pulse emission process is followed, the emission time of the time-division pulses and the output emission time are set to be consistent; the first semiconductor pump laser works and outputs the first pulse, and the other semiconductor pump lasers do not work; after the first pulse ends, the second semiconductor pump laser works and outputs the second pulse, and the other semiconductor pump lasers do not work, and the above operation is repeated until all semiconductor pump lasers have completed outputting pulses.

[0013] Specifically, the laser driving circuit includes a control chip MCU, a D / A converter, and an analog switch; the control chip MCU is connected to the input end of the D / A converter and generates a MOD signal which is transmitted to the analog switch; the control chip is connected to the analog switch and generates a D / A signal; the analog switch combines the MOD signal and the D / A signal and outputs the combined signal to a constant current source driver; the constant current source driver drives the semiconductor pump laser to emit light.

[0014] The D / A converter includes a chip U2; the analog switch is a chip U3 and a chip U1; the constant current source driver includes an operational amplifier U4, a transistor Q1, a transistor Q2, a MOS tube Q3, and resistors R1 to R7, a capacitor C1, and a capacitor C2;

[0015] Pins 1 and 2 of U1 are connected to the MCU and the signal is provided by the MCU, pin 3 is grounded, and output pin 4 is connected to pin 6 of U3; pins 1, 2, and 3 of U2 are connected to the MCU and the signal is provided by the MCU, pin 5 is grounded, output pin 6 is connected to pin 1 of U3, and output pin 4 of U3 is connected to pin 3 of op amp U4; pins 1 and 2 of U4 are short-circuited, and pin 1 is connected to one end of resistor R1, and the other end of R1 is connected to R2, C1, and pin 5 of U4; R2, C1 The other end of U4 is connected to GND; Pin 6 of U4 is connected to one end of C2, R3, and R6, and Pin 7 is connected to the other end of C2 and R3, and Pin 7 is connected to the base of Q1 and Q2; the emitter of Q1 is connected to the collector of Q2 and R4 and D1; the gate of MOS tube Q3 is connected to one end of D1, R4, and R5, and the other end of R5 is connected to GND; the source of Q3 is connected to one end of R6 and R7, and the other end of R7 is connected to GND; the drain of Q3 is connected to the negative terminal of the pump.

[0016] Specifically, a light input interface is provided on the low-loss laser spot welding head. A collimator, a reflector, a focusing lens and a protective lens are arranged in sequence in the low-loss laser spot welding head according to the direction of laser transmission. The laser is transmitted from the light input interface to the collimator and becomes parallel light, and then is reflected to the focusing lens through the reflector. After coming out of the focusing lens, it is finally focused on the surface of the workpiece to be welded through the protective lens; the focal length of the collimator is 40 to 80 mm; a CCD connected to the laser synchronization control unit point is arranged above the reflector, and the CCD magnifies the welding area of ​​the welded part to find the welding point and check the welding effect. The low-loss laser spot welding head optimizes the focal length of the collimator according to the characteristics of the large divergence angle of the output light of the existing semiconductor laser, so that the light passing efficiency reaches more than 90%. Compared with the low light transmission efficiency of the traditional welding head for the semiconductor laser, the welding head designed by the present invention greatly reduces the energy loss at the welding head.

[0017] Specifically, the power supply module includes a vehicle power supply U1, a capacitor C1, a capacitor C2, an energy storage inductor L1, a MOSFET tube Q1, a diode D1, and a load resistor R1; the capacitor C1 is connected in parallel at both ends of the vehicle power supply U1, and the energy storage inductor L1 is connected in series with the positive electrode of the vehicle power supply U1, the MOSFET tube Q1 is connected in parallel between the other end of the inductor L1 and the negative electrode of the vehicle power supply U1, and at the same time, a diode D1 is connected in series at one end of the inductor L1, and the capacitor C2 is connected in parallel before the other end of the diode D1 and the negative electrode of the vehicle power supply U1, both ends of the capacitor C2 are connected in parallel with the load resistor R1, and a PWM wave is input to the input end of the MOSFET tube Q1 to control the on and off of the MOSFET tube Q1. Charging process: The input voltage flows through the inductor L1, Q1, and capacitor C1. As the charging continues, the current on the inductor increases linearly. When it reaches a certain point, the inductor stores a certain amount of energy. During this process, the diode D1 is reverse biased and cuts off, and the capacitor C2 provides energy to the load to maintain the load operation. Discharging process: When the switch tube is not turned on, Q1 is equivalent to being disconnected. Due to the reverse electromotive force of the inductor, the current of the inductor cannot change suddenly, but will be discharged slowly and gradually. Since the original electrical circuit has been disconnected, the inductor can only discharge through the D1, load, and C1 circuits, that is, the inductor starts to charge the capacitor C2, and before charging C2, C2 has already provided voltage, so the voltage across the capacitor increases.

[0018] Specifically, the cooling module includes a water tank, a water-cooled load, a water pump, an evaporator, and a control module, wherein the water flow direction is indicated by the arrow, and the dotted line is the control circuit line. The water in the water tank flows due to the suction of the water pump, and the temperature rises due to the heat generation of the load after passing through the water-cooled load 32. The hot water flows through the evaporator and dissipates the heat, the water temperature decreases, and then flows into the water tank. During this process, the central control module monitors the load temperature in real time and achieves a constant temperature effect by adjusting the speed of the evaporator cooling fan. Since the light emission frequency of the vehicle-mounted multi-beam welding machine is not high, the load heat generation is not large, and the laser setting temperature is around 25 degrees Celsius, the self-circulating water cooling module is very effective and can meet the water cooling requirements of the vehicle-mounted multi-beam welding equipment.

[0019] This type of vehicle-mounted three-beam laser synchronous welding machine can be widely used in multi-core optical fibers, especially the coupling and welding of the currently commonly used seven-core optical fibers. In particular, when a seven-core optical fiber fan-in and fan-out device is used to achieve coupling connection in indoor or outdoor engineering applications, an advanced vehicle-mounted practical tool can also be provided for the coupling connection of seven-core optical fibers. The three-beam laser synchronous welding machine provided by the present invention is a semiconductor optical fiber laser, which adopts an independent laser module design. It is not only small in size, but can also be conveniently installed in a vehicle with limited space for mobile field operation. Moreover, the three-beam laser can independently adjust the output optical power or energy to ensure the quality of the three-beam laser synchronous welding. Since the internal optical path of the laser is all connected by optical fiber, there is no spatial optical coupling connection, which is vibration-resistant and has stable performance. The three-beam laser also has the advantages of high conversion efficiency (30%-50%), low maintenance cost, and high integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the internal control structure of a vehicle-mounted three-beam laser welding machine;

[0021] Figure 2 It is a schematic diagram of a laser module of a vehicle-mounted three-beam laser welding machine;

[0022] Figure 3 It is a structural diagram of a cold and heat exchange self-circulating refrigeration module in a vehicle-mounted three-beam laser welding machine;

[0023] Figure 4 It is a top view of the distribution of three low-loss laser spot welding heads in a vehicle-mounted three-beam laser welding machine;

[0024] Figure 5 It is the timing diagram of the double pulse sequence and the three-beam laser time-division pulse;

[0025] Figure 6 It is a vehicle power supply 24VDC-48VDC conversion power module;

[0026] Figure 7 It is a three-beam synchronous control circuit diagram;

[0027] Figure 8 This is a single-channel constant current source drive schematic;

[0028] Fig. 9 It is a diagram of the internal structure of a low-loss laser spot welding head in a vehicle-mounted three-beam laser welding machine;

[0029] Reference numerals: 20 laser synchronization control unit; 21 constant current source driver; 22 semiconductor pump laser; 23 guide red semiconductor laser; 24 optical fiber combiner; 25 output optical power sensor; 26 power transmission optical cable;

[0030] 31 water tank; 32 water cooling load; 33 water pump; 34 evaporator; 35 control module;

[0031] 41 optical input interface; 42 collimating mirror; 43 CCD; 44 reflecting mirror; 45 focusing mirror; 46 protective mirror; 47 rotating processing table;

[0032] 51 preliminary fixed pulse; 52 beam 1 output pulse; 53 beam 2 output pulse; 54 beam 3 output pulse. DETAILED DESCRIPTION

[0033] Combine the following Figures 1 to 9 The present invention is further described.

[0034] A vehicle-mounted three-beam laser welding machine, comprising a laser module, a cooling module, a power supply module, and a central control module;

[0035] The laser module includes a laser synchronization control unit 20 and three laser output units electrically connected to the laser synchronization control unit 20; the laser synchronization control unit 20 is used to control the light output and data collection of each laser output unit; the laser output unit is used to generate and output laser.

[0036] The laser output unit includes a constant current source driver 21 connected to the laser synchronization control unit 20, a guide red semiconductor laser 23 and an output optical power sensor 25. The guide red semiconductor laser 23 is a red guide laser with a wavelength window of 650nm, which guides the welding point and focuses during welding, and the output optical power is 5-30mW, and the output optical fiber is a multimode optical fiber with a core diameter of 50um or 62.5um. The constant current source driver 21 is connected to a semiconductor pump laser 22 with a wavelength of 915nm or 976nm. Since the vehicle-mounted laser requires a small volume, low loss and high efficiency, the semiconductor pump laser 22 is a single semiconductor pump laser diode structure, and the output optical power is 300W-700W, and the output optical fiber is a multimode optical fiber with a core diameter of 200um. The lasers output by the guide red semiconductor laser 23 and the semiconductor pump laser 22 are combined by the optical fiber combiner 24 and then connected to the low-loss laser spot welding head through the power transmission optical cable 26 equipped with a D80 transmission connector. The output optical power sensor 25 detects the optical power of the output light of the power transmission optical cable 26. The workpiece to be welded is placed on a rotating processing table, and multiple low-loss laser spot welding heads are evenly distributed around the workpiece to be welded. The laser synchronization control unit 20 controls the low-loss laser spot welding head to perform welding.

[0037] The welding process is as follows: the low-loss laser spot welding head welds 3 points first, and then welds 3 points after the rotary table rotates 30 degrees. The core diameter of the main optical fiber of the beam combiner is the same as the output optical fiber of the high-power semiconductor pump laser diode, which is 200um core diameter, so as to ensure the minimum loss of optical fiber welding together. The 50um or 62.5um optical fiber introduced from the side can be welded with the red semiconductor laser at low loss. The optical fiber in the optical cable has a core diameter of 200-300um. Step-type SI optical fiber and gradient GI optical fiber, such as SI300 or GI300, can be used as needed. The surface of the optical fiber output head on the D80 optical connector is coated with an anti-reflection film, i.e., AR coating, according to the wavelength of the semiconductor pump laser diode to prevent the large optical power from being reflected back to the pump laser diode on the D80, causing damage or deterioration of optical components such as the pump laser diode. If a 915nm semiconductor pumped laser diode is used, the AR anti-reflection film of D80 will have a transmission greater than 99.8% at 915nm; if a 976nm semiconductor pumped laser diode is used, the AR anti-reflection film of D80 will have a transmission greater than 99.8% at 976nm, ensuring that the reflected light at D80 is less than 0.2%.

[0038] The structure of the low-loss laser spot welding head is as follows: an optical input interface 41 is provided on the low-loss laser spot welding head, and a collimator 42, a reflector 44, a focusing mirror 45 and a protective mirror 46 are arranged in sequence in the low-loss laser spot welding head according to the laser transmission direction. The laser is transmitted from the optical input interface 41 to the collimator 42 and becomes parallel light, and then is reflected to the focusing mirror 45 by the reflector 44, and finally focuses on the surface of the workpiece to be welded by the protective mirror 46 after coming out of the focusing mirror 45; the focal length of the collimator 42 is 40 to 80 mm; a CCD 43 connected to the laser synchronization control unit 20 points is arranged above the reflector 44, and the CCD 43 magnifies the welding area of ​​the welded part to find the welding point and check the welding effect. The low-loss laser spot welding head optimizes the focal length part of the collimator 42 according to the characteristics of the large divergence angle of the output light of the existing semiconductor laser, so that the light passing efficiency reaches more than 90%. Compared with the low light passing efficiency of the traditional welding head for the semiconductor laser, the welding head designed by the present invention greatly reduces the energy loss at the welding head.

[0039] The laser synchronization control unit 20 includes a laser driving circuit, which is used to simultaneously control the semiconductor pump lasers 22 in multiple laser output units to output lasers in time-division pulses. The output energy of the beam is determined by two factors: peak power and light emission time. In order to take into account both the welding effect and the power efficiency, the laser is output in time-division pulses. The process of time-division pulse output of the laser is as follows: Figure 5 As shown, at the beginning of welding, the three beams simultaneously output a preliminary fixed pulse 51 with low energy. The purpose is to give the welded workpiece a very small pulling force to prevent displacement caused by uneven pulling force in the subsequent time-sharing welding process, which affects the overall coupling effect. The time of this preliminary fixed pulse 51 and the peak power of the light emission can be set by the user. The next step is the time-sharing pulse light emission process. The light emission time of the time-sharing pulses of the three laser synchronization control units is set. The output light emission time is consistent, and the peak power can be different. In the first pulse time, beam 1 outputs pulse 51, and beams 2 and 3 do not emit light at this time; in the second pulse time, beam 2 outputs pulse 52, and beams 1 and 3 do not emit light at this time; in the third pulse time, beam 3 outputs pulse 53, and beams 1 and 2 do not emit light at this time. The welding is completed in a very short time, and the customer cannot feel the separate light emission.

[0040] The hardware part of the laser driving circuit includes:

[0041] 1. Control chip MCU;

[0042] 2. The D / A converter includes chip U2;

[0043] 3. The analog switch is chip U3, chip U1;

[0044] 4. The constant current source driver 21 includes an operational amplifier U4, a transistor Q1, a transistor Q2, a MOS tube Q3, resistors R1 to R7, a capacitor C1, and a capacitor C2;

[0045] The connection relationship between each device is:

[0046] Pins 1 and 2 of U1 are connected to the MCU and the signal is provided by the MCU, pin 3 is grounded, and output pin 4 is connected to pin 6 of U3; pins 1, 2, and 3 of U2 are connected to the MCU and the signal is provided by the MCU, pin 5 is grounded, output pin 6 is connected to pin 1 of U3, and output pin 4 of U3 is connected to pin 3 of op amp U4; pins 1 and 2 of U4 are short-circuited, and pin 1 is connected to one end of resistor R1, and the other end of R1 is connected to R2, C1, and pin 5 of U4; R2, C1 The other end of U4 is connected to GND; Pin 6 of U4 is connected to one end of C2, R3, and R6, and Pin 7 is connected to the other end of C2 and R3, and Pin 7 is connected to the base of Q1 and Q2; the emitter of Q1 is connected to the collector of Q2 and R4 and D1; the gate of MOS tube Q3 is connected to one end of D1, R4, and R5, and the other end of R5 is connected to GND; the source of Q3 is connected to one end of R6 and R7, and the other end of R7 is connected to GND; the drain of Q3 is connected to the negative terminal of the pump.

[0047] The working principle of time division pulse is:

[0048] The MCU provides three MOD signals and three D / A signals to the analog switch. The analog switch combines these two sets of signals and provides them to the constant current source driver. The constant current source driver circuit then drives the pump to emit light.

[0049] The MOD signal controls the light emission time, and the D / A signal controls the pulse height; these two values ​​are set by the user. The three-beam time-sharing output is completed by relying on three different MOD signals. The embedded program running on the MCU controls the MOD signal switch. The timing diagram of the three MOD signals is as follows Figure 5 At the beginning of welding, the 3 DAs send a small voltage, and the 3 MODs output at the same time, so that the 3 laser beams output a small pulse at the same time, so that the weldment is initially fixed. Then the MCU controls the 3 DAs to output a large voltage, turn off the MOD2 and MOD3 signals, enable the MOD1 signal, and beam 1 emits light; after beam 1 is finished, MOD1 is turned off and MOD2 is enabled, and beam 2 emits light. After beam 2 is finished, MOD2 is turned off and MOD3 is enabled, and beam 3 emits light. After beam 3 is finished, the time-sharing pulse light emission ends.

[0050] The power supply module is used to power the laser module, the cooling module, and the electrical equipment in the central control module. The power supply module includes an on-board power supply U1, a capacitor C1, a capacitor C2, an energy storage inductor L1, a MOSFET tube Q1, a diode D1, and a load resistor R1; the capacitor C1 is connected in parallel at both ends of the on-board power supply U1, and the energy storage inductor L1 is connected in series with the positive electrode of the on-board power supply U1, and the MOSFET tube Q1 is connected in parallel between the other end of the inductor L1 and the negative electrode of the on-board power supply U1, and at the same time, a diode D1 is connected in series at one end of the inductor L1, and a capacitor C2 is connected in parallel before the other end of the diode D1 and the negative electrode of the on-board power supply U1, and both ends of the capacitor C2 are connected in parallel with the load resistor R1, and a PWM wave is input to the input end of the MOSFET tube Q1 to control the on and off of the MOSFET tube Q1. Charging process: The input voltage flows through the inductor L1, Q1, and capacitor C1. As the charging continues, the current on the inductor increases linearly. When it reaches a certain point, the inductor stores a certain amount of energy. During this process, the diode D1 is reverse biased and cuts off, and the capacitor C2 provides energy to the load to maintain the load operation. Discharging process: When the switch tube is not turned on, Q1 is equivalent to being disconnected. Due to the reverse electromotive force of the inductor, the current of the inductor cannot change suddenly, but will be discharged slowly and gradually. Since the original electrical circuit has been disconnected, the inductor can only discharge through the D1, load, and C1 circuits, that is, the inductor starts to charge the capacitor C2, and before charging C2, C2 has already provided voltage, so the voltage across the capacitor increases.

[0051] The cooling module is used to cool the laser module and the power supply module. The cooling module includes a water tank 31, a water-cooled load 32, a water pump 33, an evaporator 34, and a control module 35. The water flow direction is indicated by the arrow, and the dotted line is the control circuit line. The water in the water tank 31 flows due to the suction of the water pump 33. After passing through the water-cooled load 3232, the temperature rises due to the heat generated by the load. The hot water flows through the evaporator 34 and dissipates the heat. The water temperature decreases and then flows into the water tank 31. During this process, the central control module monitors the load temperature in real time and achieves a constant temperature effect by adjusting the speed of the cooling fan of the evaporator 34. Since the light emission frequency of the vehicle-mounted multi-beam welding machine is not high, the load heat generation is not large, and the laser setting temperature is around 25 degrees Celsius, the self-circulating water cooling module is very effective and can meet the water cooling requirements of the vehicle-mounted multi-beam welding equipment.

[0052] The central control module is electrically connected to the laser module, the cooling module, and the power supply module respectively. The central control module is used for system information collection, information interaction, laser module light output control, and temperature control functions. The central control module is connected to an external human-machine interaction interface, and the information is exchanged with external devices through the human-machine interaction interface. The human-machine interaction interface includes a touch screen 14, a communication interface network port, a serial port 15, and an external control interface 16.

[0053] This type of vehicle-mounted three-beam laser synchronous welding machine can be widely used in multi-core optical fibers, especially the coupling and welding of the currently commonly used seven-core optical fibers. In particular, when a seven-core optical fiber fan-in and fan-out device is used to achieve coupling connection in indoor or outdoor engineering applications, an advanced vehicle-mounted practical tool can also be provided for the coupling connection of seven-core optical fibers. The three-beam laser synchronous welding machine provided by the present invention is a semiconductor optical fiber laser, which adopts an independent laser module design. It is not only small in size, but can also be conveniently installed in a vehicle with limited space for mobile field operation. Moreover, the three-beam laser can independently adjust the output optical power or energy to ensure the quality of the three-beam laser synchronous welding. Since the internal optical path of the laser is all connected by optical fiber, there is no spatial optical coupling connection, which is vibration-resistant and has stable performance. The three-beam laser also has the advantages of high conversion efficiency (30%-50%), low maintenance cost, and high integration.

[0054] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A vehicle-mounted three-beam laser welding machine, characterized in that: Including laser module, cooling module, power supply module and central control module; The laser module includes a laser synchronization control unit and a plurality of laser output units electrically connected to the laser synchronization control unit; the laser synchronization control unit is used to control the light emission and data collection of each laser output unit; the laser output unit is used to generate and output laser; The power supply module is used to supply power to the laser module, the cooling module, and the electrical equipment in the central control module; The cooling module is used to cool the laser module and the power supply module; The central control module is electrically connected to the laser module, the cooling module, and the power supply module respectively. The central control module is used for system information collection, information interaction, laser module light output control, and temperature control functions. The central control module is externally connected to a human-computer interaction interface, and information is exchanged with external devices through the human-computer interaction interface. The laser output unit includes a constant current source driver connected to the laser synchronization control unit, a guide red semiconductor laser and an output optical power sensor; the constant current source driver is connected to the semiconductor pump laser, and the laser output by the guide red semiconductor laser and the semiconductor pump laser is combined by a fiber combiner and then connected to a low-loss laser spot welding head through an energy transmission optical cable equipped with a transmission connector. The workpiece to be welded is placed on a rotating processing table, and a plurality of low-loss laser spot welding heads are evenly distributed around the workpiece to be welded, and the laser synchronization control unit controls the low-loss laser spot welding heads; The laser synchronization control unit includes a laser driving circuit; the laser driving circuit is used to simultaneously control the semiconductor pump lasers in multiple laser output units to output lasers according to time-division pulses; The process of the time-division pulse laser output is as follows: the light emission time of the time-division pulses of the multiple laser synchronization control units is set to be consistent with the output light emission time, the multiple laser output units simultaneously output a preliminary fixed pulse, and then the time-division pulse light emission process is followed, the light emission time of the time-division pulse is set to be consistent with the output light emission time; The first semiconductor pump laser works and outputs the first pulse, and the other semiconductor pump lasers do not work; after the first pulse ends, the second semiconductor pump laser works and outputs the second pulse, and the other semiconductor pump lasers do not work, and the above operation is repeated until all semiconductor pump lasers finish outputting pulses; The laser driving circuit includes a control chip, a D / A converter, and an analog switch; the control chip is connected to the input end of the D / A converter and generates a MOD signal to transmit to the analog switch, the control chip is connected to the analog switch and generates a D / A signal, the analog switch combines the MOD signal and the D / A signal and outputs them to a constant current source driver, and the constant current source driver drives the semiconductor pump laser to emit light; The D / A converter includes a chip U2; the analog switch is a chip U3 and a chip U1; the constant current source driver includes an operational amplifier U4, a transistor Q1, a transistor Q2, a MOS transistor Q3, resistors R1 to R7, a capacitor C1, and a capacitor C2; Pins 1 and 2 of U1 are connected to the MCU and the signal is provided by the MCU, pin 3 is grounded, and output pin 4 is connected to pin 6 of U3; pins 1, 2, and 3 of U2 are connected to the MCU and the signal is provided by the MCU, pin 5 is grounded, output pin 6 is connected to pin 1 of U3, and output pin 4 of U3 is connected to pin 3 of op amp U4; pins 1 and 2 of U4 are short-circuited, and pin 1 is connected to one end of resistor R1, and the other end of R1 is connected to R2, C1, and pin 5 of U4; R2, C1 The other end of U4 is connected to GND; Pin 6 of U4 is connected to one end of C2, R3, and R6, and Pin 7 is connected to the other end of C2 and R3, and Pin 7 is connected to the base of Q1 and Q2; the emitter of Q1 is connected to the collector of Q2 and R4 and D1; the gate of MOS tube Q3 is connected to one end of D1, R4, and R5, and the other end of R5 is connected to GND; the source of Q3 is connected to one end of R6 and R7, and the other end of R7 is connected to GND; the drain of Q3 is connected to the negative terminal of the pump.

2. According to claim 1, a vehicle-mounted three-beam laser welding machine is characterized in that: The low-loss laser spot welding head is provided with an optical input interface, and a collimator, a reflector, a focusing lens and a protective lens are sequentially arranged in the low-loss laser spot welding head according to the laser transmission direction. The laser is transmitted from the optical input interface to the collimator and becomes parallel light, and then is reflected to the focusing lens by the reflector, and finally focuses to the surface of the workpiece to be welded by the protective lens after coming out of the focusing lens; the focal length of the collimator is 40 to 80 mm; a CCD connected to the laser synchronization control unit point is arranged above the reflector, and the CCD magnifies the welding area of ​​the weldment and images it for finding the welding point and checking the welding effect.

3. According to claim 1, a vehicle-mounted three-beam laser welding machine is characterized in that: The power supply module includes an on-board power supply U1, a capacitor C1, a capacitor C2, an energy storage inductor L1, a MOSFET tube Q1, a diode D1, and a load resistor R1; the capacitor C1 is connected in parallel at both ends of the on-board power supply U1, and the energy storage inductor L1 is connected in series with the positive electrode of the on-board power supply U1, the MOSFET tube Q1 is connected in parallel between the other end of the inductor L1 and the negative electrode of the on-board power supply U1, and at the same time, a diode D1 is connected in series at one end of the inductor L1, and a capacitor C2 is connected in parallel between the other end of the diode D1 and the negative electrode of the on-board power supply U1, both ends of the capacitor C2 are connected in parallel with the load resistor R1, and a PWM wave is input to the input end of the MOSFET tube Q1 to control the on and off of the MOSFET tube Q1.

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