Electromagnetic auxiliary magnetic head for laser-arc hybrid penetration welding and autonomous regulation and control system

Abstract

The invention discloses a laser arc composite penetration welding electromagnetic auxiliary magnetic head and an autonomous regulation and control system. The electromagnetic auxiliary magnetic head comprises a columnar hollow iron core, a coil is spirally wound outside the iron core, two ends of the iron core are connected with magnetic conductive rods respectively, a shielding shell is sleeved outside the iron core wound with the coil, and two ends of the iron core and two ends of the shielding shell are sealed; the hollow interior of the iron core serves as a first layer of cooling space, a cavity between the iron core and the shielding shell serves as a second layer of cooling space, and the two layers of cooling space are each provided with an air inlet hole and an air outlet hole. The electromagnetic auxiliary magnetic head is matched with a computer and a cold air compression device, after the magnetic field intensity is detected to deviate from a rated range through a test module, an autonomous regulation and control system dynamically sends an instruction to the cooling compression device in real time to adjust the temperature, flow and cooling time of cooling gas, and it is guaranteed that the magnetic head generates a stable magnetic field; the defects of root collapse, hump, dripping and the like of high-thermal-conductivity materials such as aluminum alloy under the working condition of long-time welding can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of laser plus arc composite heat source welding, and in particular relates to an electromagnetic auxiliary magnetic head for laser arc composite penetration welding and an autonomous control system. Background Art

[0002] Laser plus arc composite heat source welding combines the advantages of laser welding and arc welding. It can achieve single-pass penetration of highly reflective materials such as aluminum alloy with a thickness of less than 15 mm. It has the advantages of high welding speed, strong bridging ability, small deformation after welding and easy automation. For composite penetration welding of thick aluminum alloy plates, since there is no supporting structure on the back of the workpiece and the molten pool is large, the vertical downward force on the entire molten pool can easily exceed the surface tension at the bottom of the workpiece. The molten metal can easily flow to the back of the workpiece, causing root defects such as dripping, humps and weld nodules, which are difficult to effectively suppress by relying solely on process means. The existing control strategies for auxiliary penetration welding back forming are mostly: blowing protective gas on the back of the weld, notching the bottom of the workpiece or developing a back protection device. The above methods all have the problems of limited size of the workpiece to be welded, large amount of pre-welding preparation work and cumbersomeness.

[0003] At present, the external magnetic field has been widely used to assist in regulating the welding process, which helps to suppress the flow rate of the molten pool, reduce the inhibitory effect of plasma on the laser, change the distribution of the arc, refine the joint structure, and reduce welding defects. However, in the actual production process, enterprises often face large-sized components and long-term welding work. The electromagnetic coil in the magnetic field generating device will generate a lot of resistance heat due to continuous work, resulting in a decrease in the current passing through the same voltage and a decrease in the intensity of the generated magnetic field. In addition, for high thermal conductivity materials such as aluminum alloys, the temperature of the entire workpiece will increase as the welding operation proceeds, and the accumulation of heat in the parent material will further aggravate the occurrence of root defects. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention designs an electromagnetic-assisted magnetic head and an autonomous control system for laser arc composite penetration welding. This solves the problem that when electromagnetic field-assisted welding is performed on large-sized, high-thermal-conductivity, and high-reflective material components, the magnetic field intensity fluctuates violently and the root-sag defect of the workpiece is further aggravated due to the fluctuation of the magnetic permeability of the electromagnetic coil and the increase of the heat accumulation effect.

[0005] A laser arc composite penetration welding electromagnetic assisted magnetic head designed by the present invention comprises a cylindrical hollow iron core, a coil is spirally wound on the outside of the iron core, and magnetic rods are respectively connected at both ends. The outside of the iron core wound with the coil is covered with a shielding shell, and both ends of the iron core and the shielding shell are sealed to form a closed cooling structure with the hollow interior of the iron core as the first layer of cooling space and the cavity between the iron core and the shielding shell as the second layer of cooling space. The first layer of cooling space and the second layer of cooling space are both provided with air inlet and air outlet.

[0006] Furthermore, shielding covers are respectively provided at both ends of the shielding shell, and both ends of the iron core are in contact with the shielding covers.

[0007] Furthermore, the outer diameter of the shielding cover is the same as the inner diameter of the shielding shell, and the shielding cover is embedded at both ends of the shielding shell.

[0008] Furthermore, the shielding cover is provided with a blind hole corresponding to the size of the iron core, both ends of the iron core are embedded in the blind hole, the air inlet holes of the first cooling space and the second cooling space share the same air inlet channel, and the air outlet holes of the first cooling space and the second cooling space share the same air outlet channel.

[0009] Furthermore, the air inlet channel is composed of through holes that pass through the side wall of one end of the shielding shell, one of the shielding covers and the side wall of the iron core in sequence, and the air outlet channel is composed of through holes that pass through the side wall of the other end of the shielding shell, the other shielding cover and the side wall of the iron core in sequence; the through holes of the shielding cover are all connected to the second cooling space.

[0010] Furthermore, the shielding shell is provided with a groove for embedding one of the magnetic conductive rods.

[0011] Furthermore, the direction of the magnetic field formed by the magnetic conductive rod includes horizontally being parallel or perpendicular to the weld, and also includes the magnetic field penetrating the weld.

[0012] Based on the same inventive concept, the present invention also discloses an autonomous control system using the electromagnetic assisted magnetic head for laser arc composite penetration welding, including an electromagnetic assisted magnetic head, a computer test control system, an adjustable cold air compression device and a mobile platform;

[0013] The electromagnetic auxiliary magnetic head is installed on the mobile platform and arranged on the back of the full penetration weld. The magnetic field is drawn out by the magnetic rod, and moves along the weld with the welding assembly, and is distributed on both sides of the weld.

[0014] The computer test and control system is used to receive the electromagnetic auxiliary head temperature and magnetic field strength values ​​fed back by the sensor, and control the adjustable cold air compression device to adjust the cold air temperature, flow rate and cooling time of the air inlet in real time.

[0015] Furthermore, the sensor includes a temperature sensor and a magnetic field strength test module. The temperature sensor is arranged outside the shielding shell, and the magnetic field strength test module and the weld are arranged symmetrically with the magnetic rod as the axis.

[0016] Furthermore, the adjustable cold air compression device includes a gas cylinder, a gas valve and a compression cooling device, the gas valve is installed on a conduit between the gas cylinder outlet and the compression cooling device, and the compression cooling device is simultaneously connected to the computer and the air inlet.

[0017] The beneficial effects of the present invention are as follows: through the designed electromagnetic coil double-sided cooling combination structure, the magnetic head can be cooled quickly, the magnetic field strength can be stabilized, and it is easy to install and disassemble; the magnetic field strength generated by the magnetic head is detected in real time by a computer test and control system. When the magnetic field strength fluctuation exceeds a certain range, the computer dynamically adjusts the outlet temperature, flow rate and cooling time of the cold air compression device, which can stabilize the magnetic field strength within a certain range; in addition, the designed magnetic rod is very convenient to install and supports multi-posture and flexible installation, and can introduce transverse or longitudinal magnetic fields in different directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of an electromagnetic-assisted composite penetration welding autonomously controlled magnetic field cooling system;

[0019] Figure 2 The structural diagrams of the various components of the combined magnetic head: (a) complete assembly diagram of the magnetic head, (b) half-section three-dimensional diagram along the vent hole, (c) half-section front view of the vent hole, (d) shielding cover and magnetizing rod structure diagram, (e) hollow iron core structure diagram, (f) schematic diagram of the spiral coil, (g) shielding shell;

[0020] Figure 3 Schematic diagram of the distribution of magnetic rods for generating multi-directional magnetic fields for the combined magnetic head: (a) transverse magnetic field distribution perpendicular to the welding direction; (b) transverse magnetic field distribution parallel to the welding direction, (c) longitudinal magnetic field distribution;

[0021] In the figure: 1-arc welding machine, 2-arc welding gun, 3-laser head, 4-laser, 5-excitation power supply, 6-computer control system, 7-mobile platform, 8-combined magnetic head, 9-temperature sensing module, 10-magnetic field strength testing module, 11-cooling compression device, 12-gas cylinder, 13-gas valve, 14-workpiece, 15-welding direction, 16-air inlet, 17-second layer cooling space, 18-first layer cooling space, 19-through hole leading to the second layer cooling space, 20-coil, 21-lower magnetizing rod placement groove, 22-air outlet, 23-shielding shell, 24-wire hole, 25-core end face magnetizing rod groove, 26-core, 27-connecting bolt, 28-lower shielding cover, 29-lower magnetizing rod, 30-upper shielding cover, 31-shielding cover end face magnetizing rod groove, 32-upper magnetizing rod, 33-longitudinal magnetizing rod. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings. It should be pointed out that the description and exemplary embodiments herein are only used for those skilled in the art to better understand the present invention and do not constitute a limitation to the present invention.

[0023] Embodiment 1

[0024] The present embodiment discloses an electromagnetic assisted magnetic head for laser arc composite penetration welding, comprising a cylindrical hollow iron core 26, a coil 20 spirally wound on the outside of the iron core 26, magnetic rods are respectively connected at both ends, and a shielding shell 23 is sleeved on the outside of the iron core 26 wound with the coil. The iron core 26 and the shielding shell 23 are sealed at both ends to form a closed cooling structure with the hollow interior of the iron core as the first layer of cooling space 18 and the cavity between the iron core 26 and the shielding shell 23 as the second layer of cooling space 17. The first layer of cooling space 18 and the second layer of cooling space 17 are both provided with air inlets and air outlets.

[0025] An upper shielding cover 30 and a lower shielding cover 28 are respectively provided at both ends of the shielding shell 23. The outer diameter of the shielding cover is the same as the inner diameter of the shielding shell 23. The shielding cover is embedded in the shielding shell 23 and connected to the shielding shell 23 and the iron core 26 through the connecting bolts 27. The spiral coil 20 is wound around the outer side of the hollow iron core 26. The magnetic rod includes an upper magnetic rod 32 and a lower magnetic rod 29, which are connected to both ends of the iron core. They are respectively inserted into the grooves of the upper shielding cover 30 and the lower shielding cover 28, and the spiral coil wire passes through the wire hole 24 of the shielding shell 23.

[0026] The outer diameter of the hollow iron core 26 is consistent with the inner diameter of the circular step groove of the shielding cover. Four symmetrically distributed screw holes are opened on the upper and lower end surfaces for connecting the upper and lower shielding covers 30 and 28. The first layer of space 18 inside the iron core 26 is completely closed, leaving only the air inlet 16 and the air outlet 22, so that the cooling gas can cool the magnetic head 8 from the inside; the upper and lower end surfaces of the iron core 23 are both provided with oil-wiping grooves 25 for connecting the magnetic rod. In order to prevent interference, the threaded holes can be avoided at the grooves.

[0027] The air inlet 16 is opened on the upper side of the iron core 26, and the air outlet 22 is symmetrically distributed on the lower side of the iron core 26 to improve the cooling effect of the device; the spiral coil 20 is wound on the outside of the iron core 26 without blocking the air inlet and outlet, and the number of turns and layers of winding is determined according to the second layer space size of the magnetic head and the wire diameter.

[0028] The upper and lower shielding covers are provided with air inlet and outlet holes on the sides thereof, which are connected to the iron core air inlet and outlet holes 16 and 22 correspondingly. A square channel 31 is reserved on the end face for passing the two magnetic rods. The lower shielding cover is also provided with a groove 21 for placing the transverse rod of the lower magnetic rod 29 to ensure that the magnetic head can be placed horizontally on the mobile platform. The shielding cover is provided with a threaded hole on the side thereof for connecting to the outer shell 23. A wire hole 24 is also reserved on the side thereof for connecting the reserved enameled copper wire 20 to the excitation power supply 5.

[0029] The upper and lower shielding covers between the core 26 and the housing 23 also have through holes 19, which are connected to the through holes 16 that pass through the hollow core 26, and are used for the second cooling space 17 to accelerate the cooling of the magnetic head. The through holes on the shielding cover are T-shaped as a whole.

[0030] Embodiment 2

[0031] An autonomous control system using the electromagnetic assisted magnetic head for laser arc composite penetration welding in the first embodiment, comprising an electromagnetic assisted magnetic head, a computer test control system, an adjustable cold air compression device and a mobile platform;

[0032] The electromagnetic auxiliary magnetic head is set on the back of the full penetration weld, and the magnetic field is drawn out by the magnetic rod and distributed on both sides of the weld;

[0033] The computer test control system is used to receive the electromagnetic auxiliary head temperature and magnetic field strength values ​​fed back by the sensor, and control the adjustable cold air compression device to adjust the cold air temperature, flow rate and cooling time of the air inlet in real time;

[0034] The electromagnetic auxiliary magnetic head is installed on a moving platform and moves along the welding seam with the laser welding assembly.

[0035] The computer test and control system includes a temperature sensor module 9, a magnetic field strength test module 10, a computer 6 and an excitation power supply 5. The temperature sensor module 9 is attached to the side of the shielding shell 23 to obtain the surface temperature of the magnetic head. The magnetic field strength test module 10 is placed 5 mm below the magnetic rod and symmetrically distributed with the back of the workpiece about the magnetic rod, so as to accurately measure the magnetic field strength acting on the workpiece 14. The acquired data is returned to the computer 6, and fed back to the cold air conditioning device 11 after computer processing to control the cold air temperature, flow rate and cooling time in real time. Ensuring that the temperature of the magnetic head is constant within the range that can generate a stable magnetic field, such as controlling the fluctuation range of the magnetic field strength within 5mT, can effectively reduce the defects such as root collapse, hump and dripping of high thermal conductivity materials such as aluminum alloy under long-term welding conditions.

[0036] The adjustable cold air compression system consists of a gas cylinder 12, a gas valve 13, and a compression cooling device 11. The gas valve 13 is installed at the outlet of the gas cylinder 12, and the other end is connected to the compression cooling device 11 through an air duct; the other end of the compression cooling device 11 is connected to the magnetic head air inlet 16 through an air duct, and is connected to the test and control system 6 through a wire, which is used to receive feedback information to adjust the outlet air flow, cold air temperature and working time.

[0037] The laser arc welding assembly includes an arc welding machine 1, an arc welding gun 2, a laser head 3, and a laser 4. The autonomous control system of the present invention implements the functions by adopting the following steps when working:

[0038] Step 1: assemble the electromagnetic assisted magnetic head 8 from the inside out. First, connect the upper and lower shielding covers to the iron core 26 through bolts and gaskets. When connecting, the upper and lower air holes and the reserved magnetic rod channels must correspond to each other to ensure that the cooling air and the magnetic rod can pass smoothly.

[0039] Step 2: Wind the enameled insulated copper wire 20 on the hollow iron core 26 in multiple layers from bottom to top in a counterclockwise direction. The number of winding layers cannot affect the installation of the outer shell 23, and reserve upper and lower wires to be connected to the positive and negative poles of the excitation power supply 5 respectively; put the outer shell on the magnetic head from top to bottom, and when it is halfway put on, pass the wire through the reserved wire hole 24, and use bolts to seal and connect the upper and lower shielding covers.

[0040] Step three, place the lower magnetic rod 29 in the rectangular groove 21 corresponding to the lower shielding cover 28, directly put the upper magnetic rod 32 into the square channel 31 of the upper shielding cover, attach the temperature sensor module 9 to the side of the shielding shell 23, and hang the magnetic field strength test module 10 under the magnetic rod to complete the installation of the combined magnetic head 8.

[0041] Step 4. After completing the installation of the combined magnetic head, install the air cylinder and the ventilation pipe of the air compressor and connect them to the ventilation hole of the magnetic head. Connect the reserved electromagnetic coil wire to the excitation power supply. Connect the cold air compression device, test module and excitation power supply to the computer.

[0042] Step 5: Place the complete magnetic head 8 on the mobile platform 7, with the magnetic rod 5 mm below the welding position of the workpiece 14, and adjust the placement direction according to the required magnetic field direction, as shown in the attached figure. Figure 3 As shown, the welding direction 15, the horizontal transverse magnetic field can be parallel to the weld direction or perpendicular to the weld. Figure 3 (a) is perpendicular to the weld, (b) is horizontal and parallel to the weld. If a longitudinal magnetic field is required, as shown in the attached Figure 3 As shown in (c), replace the longitudinal magnetic rod 33, and then close the square groove 21 of the lower shielding cover. The industry defaults to adding the N-level magnetic field to the back of the workpiece, and then the longitudinal magnetic field can be obtained. The laser arc hybrid welding gun is adjusted to the position just above the workpiece 14 where welding starts.

[0043] Step 6: Turn on the excitation power supply, cold air compression device and computer control system, adjust the current and voltage of the excitation power supply to set the required magnetic field strength, set the moving platform speed to the same as the welding speed and start it synchronously under computer control, so that the magnetic head always acts directly below the molten pool, wait for the excitation current and voltage to stabilize, and then start welding. During the welding process, when the fluctuation amplitude of the detected magnetic field strength exceeds the limit value, the computer autonomously controls the cooling compression device, dynamically adjusts the flow rate, temperature and cooling time of the cooling gas, until the magnetic field strength reaches the predetermined range.

[0044] The above is a detailed description of the specific implementation methods of the present invention in conjunction with the accompanying drawings, but it should be noted that the present invention is not limited to the above-specified implementation methods, and those skilled in the art can make corresponding changes according to the scope of the claims.

Claims

1. A laser arc hybrid penetration welding electromagnetic assisted magnetic head, characterized in that: The invention comprises a columnar hollow iron core (26), a coil (20) is spirally wound on the outside of the iron core (26), and magnetic rods are connected to the two ends respectively. The iron core (26) wound with the coil is covered with a shielding shell (23) on the outside. The iron core (23) and the shielding shell (23) are sealed at both ends to form a closed cooling structure with the hollow interior of the iron core as the first layer of cooling space (18) and the cavity between the iron core (26) and the shielding shell (23) as the second layer of cooling space (17). The first layer of cooling space (18) and the second layer of cooling space (17) are both provided with air inlet holes and air outlet holes.

2. The electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to claim 1, characterized in that: Shielding covers are respectively provided at both ends of the shielding shell (23), and both ends of the iron core (23) are in contact with the shielding covers.

3. The electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to claim 2, characterized in that: The outer diameter of the shielding cover is the same as the inner diameter of the shielding shell (23), and the shielding cover is embedded at both ends of the shielding shell (23).

4. The electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to claim 1, characterized in that: The shielding cover is provided with a blind hole corresponding to the size of the iron core (26), and both ends of the iron core (26) are embedded in the blind hole. The air inlet holes of the first cooling space (18) and the second cooling space (17) are the same air inlet channel, and the air outlet holes of the first cooling space (18) and the second cooling space (17) are the same air outlet channel.

5. The electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to claim 4, characterized in that: The air inlet passage is composed of through holes that pass through the side wall of one end of the shielding shell (23), one of the shielding covers and the side wall of the iron core (26) in sequence, and the air outlet passage is composed of through holes that pass through the side wall of the other end of the shielding shell (23), the other shielding cover and the side wall of the iron core (26) in sequence; the through holes of the shielding cover are all connected to the second cooling space.

6. The electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to claim 1, characterized in that: The shielding shell (23) is provided with a groove for embedding one of the magnetic conductive rods.

7. The electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to claim 1, characterized in that: The direction of the magnetic field formed by the magnetic rod includes horizontally being parallel or perpendicular to the weld, and also includes the magnetic field penetrating the weld.

8. An autonomous control system using the electromagnetic assisted magnetic head for laser arc hybrid penetration welding according to any one of claims 1 to 7, characterized in that: It includes an electromagnetic auxiliary magnetic head (8), a computer test control system, an adjustable cold air compression device and a mobile platform (7); The electromagnetic auxiliary magnetic head is installed on a mobile platform (7) and is arranged on the back of a workpiece (14) for full penetration welding. The magnetic field is drawn out by a magnetic rod and distributed on both sides of the weld. The computer test and control system is used to receive the electromagnetic auxiliary head temperature and magnetic field strength values ​​fed back by the sensor, and control the adjustable cold air compression device to adjust the cold air temperature, flow rate and cooling time of the air inlet in real time.

9. The autonomous control system according to claim 8, characterized in that: The sensor comprises a temperature sensor (9) and a magnetic field strength test module (10); the temperature sensor (9) is mounted outside the shielding shell (23); and the magnetic field strength test module (10) and the weld are arranged symmetrically with the magnetic rod as the axis.

10. The autonomous control system according to claim 8, characterized in that: The adjustable cold air compression device comprises a gas cylinder (12), a gas valve (13) and a compression cooling device (11); the gas valve (13) is installed on a conduit between the outlet of the gas cylinder (12) and the compression cooling device (11); and the compression cooling device (11) is simultaneously connected to a computer (6) and an air inlet.

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