Disclosure of Invention
The purpose of the invention is: the laser-plasma arc composite cutting and welding processing device is provided to solve the problems that the service life of an arc cathode is influenced by the overheating phenomenon of the end surface of the annular cathode during laser-plasma arc welding in the prior art; the invention also provides a laser-plasma arc composite cutting and welding processing method.
In order to achieve the above object, the present invention provides a laser-plasma arc hybrid cutting and welding apparatus, which includes a housing, wherein a central passage through which laser passes is formed in the housing, a nozzle is further disposed at the bottom of the housing, the nozzle includes a gas nozzle for ejecting an auxiliary gas and a plasma nozzle disposed inside the gas nozzle for ejecting a plasma beam, a cutting electrode and a welding electrode are further disposed at intervals outside the housing along a circumferential direction of the housing, the cutting electrode and the welding electrode are needle electrodes, bottom ends of the cutting electrode and the welding electrode are disposed to be inclined toward the housing, and an interval between the bottom ends of the cutting electrode and the welding electrode and a center line of the central passage is larger than a radius of the laser passing through the cutting electrode and the welding electrode.
Preferably, the cutting electrode has a cone angle of 60-90 °.
Preferably, the welding electrode has a cone angle of 15-30 °
Preferably, the plasma nozzle is an adjustable nozzle with adjustable diameter, and the diameter of the plasma nozzle is adjusted within the range of 1-5 mm.
The invention also provides a laser-plasma arc composite cutting and welding processing method, which comprises the following steps of firstly, adopting a needle electrode as a cutting electrode and a welding electrode, and adjusting the angles of the cutting electrode and the welding electrode to enable the bottom ends of the cutting electrode and the welding electrode to incline towards a laser channel; adjusting the interval between the bottom ends of the cutting electrode and the welding electrode and the central line of the central channel, wherein the interval is larger than the radius of the laser passing through the cutting electrode and the welding electrode; adjusting the diameter of the plasma nozzle to enable the diameter of the plasma nozzle to meet the contraction of the electric arc; and step four, starting the control system, and adjusting the flow rate of the gas nozzle, the power of the laser, the focus of the laser beam, and the current ranges of the cutting electrode and the welding electrode in the control system to weld.
Preferably, in the first step, the taper angle of the cutting electrode is 60-90 DEG, and the taper angle of the welding electrode is 15-30 DEG
Preferably, in the third step, the diameter of the plasma nozzle is adjusted within the range of 1-5 mm.
Preferably, in the fourth step, the gas flow rate of the gas nozzle during welding is 0.1-10.0L/min, and the gas flow rate of the gas nozzle during cutting is 15.0-150.0L/min.
Preferably, the power of the laser is 1.0-5.0kW and the focal point of the laser beam varies from the surface of the workpiece to 0-50% of the thickness of the workpiece.
Preferably, the current ranges from 30 to 120A for cutting and from 50 to 250A for welding.
Compared with the prior art, the laser-plasma arc composite cutting and welding processing device and the processing method have the advantages that: the cutting electrode and the welding electrode are needle electrodes and are arranged outside the shell to replace annular electrodes arranged on a laser line, so that the laser is prevented from being reflected to the end face of the cathode by a radiation processing area, auxiliary gas sprayed by the gas nozzle flows to the needle electrodes to be ionized at the needle electrodes to form plasma beams, the laser is emitted from the central channel and penetrates through the bottom ends of the cutting electrode and the welding electrode, because the interval between the bottom ends of the cutting electrode and the welding electrode and the central line of the central channel is larger than the radius of the laser when passing through the cutting electrode and the welding electrode, the laser cannot irradiate the needle electrodes when passing through the bottom ends of the cutting electrode and the welding electrode, the heat radiation of the laser at the needle electrodes is avoided, meanwhile, the laser beam cuts off plasma gas flow before the plasma flow impacts the needle electrodes, and a controlled channel for improving the conductivity of the plasma beams is formed, the electric arc can be stably focused and transmitted in the plasma beam, the local overheating phenomenon of the electrode is avoided, and the service life of the cathode is prolonged.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
The preferred embodiment of the laser-plasma arc hybrid cutting and welding processing device comprises a shell 1, a nozzle, a cutting electrode 4 and a welding electrode 5, wherein the nozzle comprises a gas nozzle 3 and a plasma nozzle 2, the gas nozzle 3 is arranged at the bottom end of the shell 1, the top end of the shell 1 is used for being connected with an external laser generator, and a central channel 11 for laser to pass through is arranged in the shell 1, as shown in figure 1.
The gas nozzle 3 is used for injecting an auxiliary gas, which is an inert gas or a mixed gas containing an inert gas, and the gas nozzle 3 is arranged coaxially with the central passage 11 of the housing 1. The gas nozzle 3 ejects an auxiliary gas, which flows to the welding electrode 5 and the cutting electrode 4 through gaps between the welding electrode 5 and the cutting electrode 4 and the workpiece 6 to be machined, and is ionized at the needle-like electrodes to form a plasma beam.
The plasma nozzle 2 is arranged inside the gas nozzle 3, the plasma nozzle 2 is used for passing through the plasma beam and the laser, and the plasma nozzle 2 is arranged coaxially with the gas nozzle 3. The plasma nozzle 2 is an adjustable nozzle with an adjustable diameter, the diameter of the plasma nozzle 2 is adjusted within the range of 1-5mm, the contraction of the arc can be adjusted by adjusting the diameter of the plasma nozzle 2, and the position of the arc relative to the workpiece 6 can be controlled by the focal point of the focused laser beam. During welding or cutting, the plasma nozzle 2 is perpendicular to the workpiece 6 or at an angle of up to 20 ° relative to the perpendicular to the surface of the workpiece 6.
The needle electrodes are obliquely arranged, the bottom ends of the needle electrodes are close to the shell 1, the top ends of the needle electrodes are far away from the shell 1, the cutting electrodes 4 and the welding electrodes 5 are respectively arranged on two sides of the shell 1, the included angles between the cutting electrodes 4 and the welding electrodes 5 and the central line of the central channel 11 are 10-30 degrees, the cone angle of the cutting electrodes 4 is 60-90 degrees, and the cone angle of the welding electrodes 5 is 15-30 degrees. The cutting electrode 4 and the welding electrode 5 may be arranged in plurality at intervals around the circumference of the housing 1, and are selected according to the working strength.
The bottom end of the needle electrode and the central line of the central channel 11 have a space, the space is larger than the radius of the laser beam when the laser beam passes through the bottom ends of the cutting electrode 4 and the welding electrode 5, the laser does not irradiate the needle electrode when passing through the bottom ends of the cutting electrode 4 and the welding electrode 5, the heat of the laser is prevented from radiating on the needle electrode, meanwhile, the laser beam cuts off the plasma airflow before the plasma airflow impacts the needle electrode, a controlled channel for improving the conductivity of the plasma beam is formed, and the electric arc can be stably focused and transmitted in the plasma beam.
During the welding process, a shielding gas is sprayed to the outside of the laser-plasma beam, so that the plasma beam is wrapped by the shielding gas. During the cutting process, the cutting electrode 4 is protected by inert gas because oxygen, compressed air or water vapor may be mixed into the plasma beam, wherein the ratio of the mixed oxygen, compressed air or water vapor may reach 40% -60%.
The invention relates to a laser-plasma arc composite cutting and welding processing method, namely a using method of the light-plasma arc composite cutting and welding processing device, which comprises the following steps:
step one, adopting needle electrodes as a cutting electrode 4 and a welding electrode 5, and adjusting the angles of the cutting electrode 4 and the welding electrode 5 to enable the bottom ends of the cutting electrode 4 and the welding electrode 5 to incline towards a laser channel.
Preferably, the cutting electrode 4, the welding electrode 5 and the central line of the central channel 11 form an included angle of 10-30 degrees, the cone angle of the cutting electrode 4 is 60-90 degrees, and the cone angle of the welding electrode 5 is 15-30 degrees
And step two, adjusting the intervals between the bottom ends of the cutting electrode 4 and the welding electrode 5 and the central line of the central channel 11, wherein the intervals are larger than the radius of the laser passing through the cutting electrode 4 and the welding electrode 5.
And step three, adjusting the diameter of the plasma nozzle 2 to enable the diameter of the plasma nozzle 2 to meet the contraction of the electric arc.
Preferably, the diameter of the plasma nozzle 2 is adjusted in the range of 1-5mm, the plasma nozzle 2 is coaxial with the laser beam, and the plasma nozzle 2 is perpendicular to the workpiece 6 or at an angle of up to 20 ° with respect to the perpendicular to the surface of the workpiece 6.
And step four, starting the control system, and adjusting the flow rate of the gas nozzle 3, the power of the laser, the focus of the laser beam and the current ranges of the cutting electrode 4 and the welding electrode 5 in the control system to weld.
Preferably, at the time of welding, a shielding gas is sprayed to the outside of the laser-plasma beam, wherein the gas flow rate of the gas nozzle 3 is 0.1 to 10.0L/min, and the flow rate of the shielding gas is 10.0 to 30.0L/min. When cutting, the gas flow rate of the gas nozzle 3 is 15.0-150.0L/min, and protective gas is sprayed to the cutting electrode 4 to protect the cutting electrode 4, because oxygen, compressed air or water vapor may be mixed into the plasma beam, and the proportion of the mixed oxygen, compressed air or water vapor can reach 40% -60%.
Preferably, the power of the laser is 1.0-5.0kW and the focal point of the laser beam varies from the surface of the workpiece 6 to 0-50% of the thickness of the workpiece 6.
The auxiliary gas generates plasma at the welding electrode 5 and the cutting electrode 4, the laser beam cuts off the plasma gas flow before the plasma gas flow impacts the welding electrode 5 and the cutting electrode 4, a controlled channel for improving the conductivity of the plasma beam is formed, the plasma beam generated by the needle electrode is guided to pass through the plasma nozzle 2 to the workpiece 6, the stability of the plasma beam during high-speed processing is improved, and coaxial transmission and processing of the laser beam and the plasma beam are realized.
In the present embodiment, the laser beam and the plasma beam are continuous; in other embodiments, the laser beam and plasma beam may also be pulsed, and the jet may be additionally pulsed using a pulsed mode at a frequency of 10-40kHz within a single pulse for additional compression of the plasma.
Preferably, the current ranges from 30 to 120A for cutting and from 50 to 250A for welding.
During specific construction, taking a Q345 carbon steel material with the size of 400 multiplied by 200 multiplied by 8mm as an example, during cutting, the included angle between the welding electrode 5 and the central line of a laser beam is 30 degrees, the cone angle of the cutting electrode 4 is 65 degrees, the cone angle of the welding electrode 5 is 20 degrees, the diameter of the plasma nozzle 2 is 2mm, the power of the laser is 2.0kw, the cutting current is 80A, the auxiliary gas is argon, the pressure of the argon is 0.5MPa, the tassel of the auxiliary gas is 270/min, the cutting speed can be increased to 800m/h, and meanwhile, the roughness of the edge of a cut is reduced.
Taking the case of the bevelless butt welding of 8mm thick SUS304 stainless steel as an example, during welding, the laser power is 2.0kW, the welding current is 200A, argon gas is used as auxiliary gas, the pressure of the auxiliary gas is 0.15MPa, and the gas flow rate is 2.8L/min. Meanwhile, the protective gas is argon, the pressure of the protective gas is 0.15MPa, the airflow speed is 17L/min, the maximum welding speed reaches 18m/h, and the forming quality of the welding seam is also improved.
To sum up, the embodiment of the present invention provides a laser-plasma arc hybrid cutting and welding apparatus, wherein the cutting electrode and the welding electrode are needle electrodes and are disposed outside the housing, instead of a ring electrode disposed on the laser line, to prevent the laser from being reflected from the radiation processing region to the end surface of the cathode, the auxiliary gas ejected from the gas nozzle flows to the needle electrodes, and is ionized at the needle electrodes to form a plasma beam, the laser is ejected from the central channel and passes through the bottom ends of the cutting electrode and the welding electrode, because the distance between the bottom ends of the cutting electrode and the welding electrode and the central line of the central channel is greater than the radius of the laser when passing through the cutting electrode and the welding electrode, the laser does not irradiate the needle electrodes when passing through the bottom ends of the cutting electrode and the welding electrode, to prevent the heat of the laser from being radiated at the needle electrodes, and the laser beam cuts off the plasma gas flow before the plasma flow impacts, a controlled channel for improving the conductivity of the plasma beam is formed, so that the electric arc can be stably focused and transmitted in the plasma beam, the local overheating phenomenon of the electrode is avoided, and the service life of the cathode is prolonged.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.