Automatic plasma surfacing device and process for surface of rotary blade

Abstract

The invention belongs to the technical field of plasma surfacing, and discloses a rotary blade surface plasma automatic surfacing device which comprises a plasma surfacing system, a motion adjusting mechanism, a turnover mechanism and a four-axis numerical control system. The plasma surfacing welding system is composed of a surfacing welding machine, a welding gun, a powder storage device, a water tank, an argon bottle and a conductive clamp, and accurate feeding and cooling in the welding process are achieved through connection of a powder conveying pipe, a cooling water pipe and an air feeding pipe. The motion adjusting mechanism comprises an X-axis guide rail, a Y-axis guide rail and a Z-axis module, and accurate motion of the welding gun is controlled through a four-axis numerical control system. The turnover mechanism drives the rotary blade to turn over through a motor and a speed reducer, and the turnover angle is adjusted through a four-axis numerical control system. Through cooperative control of the four-axis numerical control system, it is ensured that a proper angle is kept between the welding gun and the surface of the rotary blade, interference is avoided, the high-precision and stable surfacing process is achieved, the surfacing device is suitable for automatic batch production, and surfacing efficiency and quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of plasma surfacing, and in particular relates to a process of a plasma automatic surfacing device for a rotary blade surface. Background Art

[0002] Plasma surfacing of a wear-resistant alloy layer on the surface of a steel substrate can significantly improve the surface hardness and wear resistance. This technology has been widely used in the field of industrial additive manufacturing and repair, such as the repair of mining machinery parts, turbine rotor shafts, valve wear and pump maintenance. In the field of agricultural machinery, especially the soil-contacting parts of agricultural machinery equipment, there are more serious wear problems. Take the rotary tiller as an example. Excessive wear leads to frequent replacement, which seriously affects the operating quality of the equipment and delays the normal progress of agricultural production.

[0003] To solve this problem, traditional processes generally choose to heat treat the rotary blade again or spray a layer of wear-resistant coating on its surface. However, the rotary blade has the problem of temper brittleness during heat treatment. An inappropriate tempering range may greatly increase the brittleness of the blade, thereby increasing the risk of blade breakage. In addition, the working environment of the rotary blade is special and is often subjected to impact loads. The coating may fall off due to stress concentration. The strengthening effect of traditional heat treatment processes and spray coatings is limited, and the implementation is complicated, making it difficult to achieve mass production.

[0004] At present, although plasma surfacing technology has been widely used in the field of industrial additive manufacturing and repair, it has the advantages of strong metallurgical bonding, low equipment cost, simple process, and the performance of the surfacing alloy layer is significantly better than that of the substrate, which can effectively avoid excessive wear of the substrate. However, in the field of agricultural machinery, there are still technical barriers to the application of surface strengthening for complex structural parts such as rotary tillers. Some studies at home and abroad have tried to use plasma surfacing technology for surface strengthening of agricultural machinery soil-contacting parts, such as plasma hardened plow tips, plasma hardened deep tillage shovel tips, etc. However, at present, the surface strengthening of most agricultural machinery soil-contacting parts is still mainly manual arc surfacing. Although manual arc surfacing can still cope with the surfacing of some relatively regular and thick workpieces, for workpieces with thin thickness and special spatial curved surface structures, such as rotary tillers and other parts with cutting requirements, manual arc surfacing often needs to be carried out in several times, and the surfacing accuracy is low, the quality is poor, the stability is poor, and it is easily affected by human factors. In addition, there is a large demand for rotary tillage knives. The number of knives in a rotary tiller can reach dozens to hundreds. Therefore, manual surfacing is not only labor-intensive, but also not suitable for large-scale, automated production needs. Summary of the invention

[0005] The invention provides a process of a rotary blade surface plasma automatic surfacing device to solve the existing technical problems.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is: A rotary tiller blade surface plasma automatic surfacing device comprises a frame, and a plasma surfacing system, a motion regulating mechanism, a turning mechanism and a four-axis numerical control system connected to the frame; The plasma surfacing system comprises a plasma surfacing machine, a welding gun, a powder storage device, a water tank, an argon gas bottle and a conductive clamp arranged on a frame, wherein the plasma surfacing machine is connected to the welding gun, the powder storage device is connected to the welding gun through a powder conveying pipe, the water tank is connected to the welding gun through a cooling water pipe to form a circulation loop, the argon gas bottle is connected to the plasma surfacing machine through an air supply pipe, and the conductive clamp is connected to the plasma surfacing machine and is used to be electrically connected to a rotary tiller to form a current loop; The motion adjustment mechanism includes an X-axis guide rail, a Y-axis guide rail, and a Z-axis module arranged on a frame, the frame is connected to the X-axis guide rail, the Y-axis guide rail, and the Z-axis module and is used to install a welding gun, and the four-axis CNC system controls and connects the X-axis guide rail, the Y-axis guide rail, and the Z-axis module to enable the welding gun to move accurately along the three axes of X, Y, and Z; The flipping mechanism comprises a motor, a reducer, a flipping platform and a clamp arranged on a frame, wherein the motor drives the flipping platform to flip through the reducer, the clamp is installed on the flipping platform and is used to clamp the rotary tiller, and the four-axis CNC system controls the flipping platform to flip the rotary tiller around a horizontal axis; The plasma surfacing system, motion adjustment mechanism and flip mechanism, under the cooperative control of the four-axis CNC system, jointly adjust the angle of the rotary blade and the position of the welding gun to ensure that the surface of the rotary blade and the welding gun maintain a distance to avoid interference, thereby achieving plasma surfacing on the surface of the rotary blade.

[0007] As a further improvement of the above technical solution: The frame is also provided with a screw lifting mechanism, the top of which is connected to the motion adjustment mechanism, and the four-axis numerical control system is control-connected to the screw lifting mechanism and can adjust the height of the motion adjustment mechanism along the Z-axis direction.

[0008] The plasma cladding machine is provided with an airflow control device, which is used to adjust the gas flow rate, and the welding gun is connected to the argon gas bottle through the airflow control device.

[0009] The plasma surfacing system further comprises a secondary cooling device, which is connected to the welding gun via a cooling pipeline to enhance the cooling capacity of the welding gun.

[0010] A plasma automatic surfacing process for a rotary tiller blade surface comprises the following steps: S1. Use the four-axis CNC system to set the running trajectory of the welding gun according to the surface trajectory of the rotary blade edge, generate the coordinates of the trajectory points, and ensure that when the welding gun passes through the bending area of ​​the rotary blade, the motor is controlled to drive the flip platform to flip the rotary blade to avoid interference between the welding gun and the rotary blade; S2. During the movement of the welding gun, the welding gun is controlled to perform surfacing along the movement trajectory, and the parameters of the welding gun swing speed, swing width, and distance between the gun muzzle and the surface of the rotary blade are optimized to adjust the coating overlap rate; S3. Complete the motion path programming of the welding gun in the four-axis CNC system and set the cycle program to ensure the automation and continuity of the cladding process; S4, start the plasma cladding system, adjust the powder feeding amount and current parameters of the welding gun, start the plasma cladding machine for welding, and after the cladding is completed, extinguish the arc and discharge the remaining powder in the powder storage device.

[0011] In S1, when the welding gun passes through the bending part of the rotary blade, the motor is controlled to rotate twice according to the bending angle of the rotary blade to drive the flipping platform to flip the rotary blade, and the coating thickness is reserved to avoid interference; in S4, it is confirmed that the cooling water circulation of the water tank is normal and the conductive clamp is clamped in place.

[0012] Compared with the prior art, the present invention has the following beneficial effects: By integrating the plasma surfacing system, the motion adjustment mechanism, the flip mechanism and the four-axis CNC system, the surfacing operation on the surface of the rotary blade can be completed efficiently and accurately. Compared with the traditional welding method, the present invention has significant advantages. First, the plasma arc is used as the heat source, and combined with synchronous powder feeding, it can effectively improve the surfacing efficiency, reduce the consumption of welding materials, and ensure the welding quality. Second, the four-axis CNC system accurately controls the position of the welding gun and the rotary blade, especially the cooperation of the flip mechanism, which can accurately adjust the angle of the rotary blade to adapt to the welding requirements of the special spatial curved surface of the rotary blade edge and avoid interference. Third, the cooling system of the water tank, the gas supply of the argon gas bottle, the current loop of the conductive clamp and other designs ensure the stability of the welding process and improve the surfacing quality. In addition, the CNC welding control system is adopted, the surfacing process has good repeatability, and it is easy to realize automated mass production, which significantly reduces the production time, workload and cost, and at the same time improves the stability of the surfacing process and the overall quality of the product, especially in terms of continuity and aesthetics at the bending angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a structural schematic diagram of a rotary tiller blade surface automatic plasma surfacing device.

[0015] Figure 2 It is an assembly diagram of the motion adjustment mechanism.

[0016] Figure 3 It is a schematic diagram of the structure of the flip mechanism when viewed from above.

[0017] Figure 4 It is a flow chart of the automatic plasma surfacing process on the surface of rotary tiller blade.

[0018] Legend: 100. Rotary tiller blade; 1. Frame; 11. Screw lifting mechanism; 2. Plasma cladding system; 21. Plasma cladding machine; 22. Welding gun; 23. Powder storage device; 24. Water tank; 25. Argon cylinder; 3. Motion adjustment mechanism; 31. X-axis guide rail; 32. Y-axis guide rail; 33. Z-axis module; 4. Flipping mechanism; 41. Motor; 42. Reducer; 43. Flipping platform; 44. Fixture; 5. Four-axis CNC system. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0020] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0021] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0022] Example: Figure 1-Figure 3 As shown, the rotary blade surface plasma automatic surfacing device of this embodiment includes a frame 1, and a plasma surfacing system 2, a motion adjustment mechanism 3, a flip mechanism 4 and a four-axis CNC system 5 connected to the frame 1; The plasma cladding system 2 includes a plasma cladding machine 21, a welding gun 22, a powder storage device 23, a water tank 24, an argon gas bottle 25 and a conductive clamp arranged on the frame 1. The plasma cladding machine 21 is connected to the welding gun 22, the powder storage device 23 is connected to the welding gun 22 through a powder conveying pipe, the water tank 24 is connected to the welding gun 22 through a cooling water pipe to form a circulation loop, the argon gas bottle 25 is connected to the plasma cladding machine 21 through an air supply pipe, and the conductive clamp is connected to the plasma cladding machine 21 and is used to be electrically connected to the rotary blade 100 to form a current loop; The motion adjustment mechanism 3 includes an X-axis guide rail 31, a Y-axis guide rail 32, and a Z-axis module 33 arranged on the frame 1. The frame 1 is connected to the X-axis guide rail 31, the Y-axis guide rail 32, and the Z-axis module 33 and is used to install the welding gun 22. The four-axis CNC system 5 controls the X-axis guide rail 31, the Y-axis guide rail 32, and the Z-axis module 33 to enable the welding gun 22 to move accurately along the three axes of X, Y, and Z. The turning mechanism 4 includes a motor 41, a reducer 42, a turning platform 43 and a clamp 44 arranged on the frame 1. The motor 41 drives the turning platform 43 to turn through the reducer 42. The clamp 44 is installed on the turning platform 43 and is used to clamp the rotary tiller 100. The four-axis CNC system 5 controls the turning platform 43 to turn the rotary tiller 100 around the horizontal axis. Under the collaborative control of the four-axis CNC system 5, the plasma surfacing system 2, the motion adjustment mechanism 3 and the flipping mechanism 4 jointly adjust the angle of the rotary blade 100 and the position of the welding gun 22 to ensure that the surface of the rotary blade 100 maintains a distance from the welding gun 22 to avoid interference, thereby achieving plasma surfacing on the surface of the rotary blade 100.

[0023] The automatic plasma surfacing device for the surface of the rotary blade of this embodiment can efficiently and accurately complete the surfacing operation on the surface of the rotary blade 100 by integrating the plasma surfacing system 2, the motion adjustment mechanism 3, the flipping mechanism 4 and the four-axis numerical control system 5. Compared with the traditional welding method, the present invention has significant advantages. First, the use of plasma arc as a heat source, combined with synchronous powder feeding, can effectively improve the surfacing efficiency, reduce the consumption of welding materials, and ensure the welding quality. Second, the four-axis numerical control system 5 accurately controls the position of the welding gun 22 and the rotary blade 100, especially the cooperation of the flipping mechanism 4, which can accurately adjust the angle of the rotary blade 100 to adapt it to the welding requirements of the special spatial curved surface of the blade edge of the rotary blade 100 to avoid interference. Third, the design of the cooling system of the water tank 24, the gas supply of the argon gas bottle 25, the current loop of the conductive clamp, etc., ensures the stability of the welding process and improves the surfacing quality. Fourthly, the welding gun controller in the four-axis CNC system 5 can control the welding gun 22 to move along any straight line in three-dimensional space. It only needs to extract the blade trajectory of the rotary blade 100. Since the position of the rotary blade 100 fixture 44 set on the flip platform 43 is fixed, the position of each rotary blade 100 is also fixed. It is only necessary to control the welding gun 22 to be at the starting position of the program before each operation to ensure accurate welding. In addition, the CNC welding control system is used, the surfacing process has good repeatability, and it is easy to realize automated mass production, which significantly reduces production time, workload and cost, and at the same time improves the stability of the surfacing process and the overall quality of the product, especially in terms of continuity and aesthetics at the bending angle.

[0024] In this embodiment, a screw lifting mechanism 11 is also provided on the frame 1, the top of the screw lifting mechanism 11 is connected to the motion adjustment mechanism 3, and the four-axis numerical control system 5 is controlled and connected to the screw lifting mechanism 11, and can adjust the height of the motion adjustment mechanism 3 along the Z-axis direction. It can realize a large adjustment of the welding gun 22 in the vertical direction, which can greatly supplement the adjustment range of the motion adjustment mechanism 3 in the Z-axis direction, improve the flexibility and adaptability in the surfacing process, especially when facing rotary blades 100 of different shapes or heights, it can maintain the correct position of the welding gun 22 to ensure the quality of surfacing.

[0025] In this embodiment, an airflow control device is provided in the plasma cladding machine 21, and the airflow control device is used to adjust the gas flow rate, and the welding gun 22 is connected to the argon gas bottle 25 through the airflow control device. The airflow control device can accurately control the gas flow rate, optimize the stability of the plasma arc and the gas protection during the cladding process, avoid defects such as pores and cracks during the welding process, improve the quality and stability of the cladding, and can adjust the airflow as needed to meet different process requirements.

[0026] In this embodiment, the plasma surfacing system 2 also includes a secondary cooling device, which is connected to the welding gun 22 through a cooling pipeline to enhance the cooling capacity of the welding gun 22, effectively reducing the risk of overheating of the welding gun 22, ensuring the long-term stable operation of the welding gun 22 in a high temperature environment, extending the service life of the welding gun 22, and improving the welding quality. Especially in high-power surfacing, the secondary cooling system can provide additional thermal management to prevent the welding gun 22 from experiencing performance degradation due to overheating.

[0027] In this embodiment, Figure 4 As shown, the plasma automatic surfacing process for the surface of the rotary tiller blade of this embodiment includes the following steps: S1. Use the four-axis numerical control system 5 to set the running track of the welding gun 22 according to the surface track of the blade of the rotary blade 100, generate the coordinates of the track points, and ensure that when the welding gun 22 passes through the bending area of ​​the rotary blade 100, the motor 41 is controlled to drive the flip platform 43 to flip the rotary blade 100 to avoid interference between the welding gun 22 and the rotary blade 100; S2. During the movement of the welding torch 22, the welding torch 22 is controlled to perform surfacing welding along the movement trajectory, and the parameters of the swing speed, swing width, and the distance between the gun muzzle and the surface of the rotary blade 100 of the welding torch 22 are optimized to adjust the coating overlap rate; S3, completing the motion path programming of the welding gun 22 in the four-axis CNC system 5, setting the cycle program, and ensuring the automation and continuity of the cladding process; S4, start the plasma cladding system 2, adjust the powder feeding amount and current parameters of the welding gun 22, start the plasma cladding machine 21 to perform welding operations, and after the cladding is completed, extinguish the arc and discharge the remaining powder in the powder storage 23.

[0028] By adopting synchronous powder feeding and CNC welding control system, the motion trajectory, speed and gas supply of welding gun 22 are precisely controlled to ensure the uniformity and consistency of the surfacing process, which is particularly suitable for surfacing of complex spatial curved surfaces such as rotary tiller blade 100. Plasma arc as a heat source improves surfacing efficiency, reduces defective product rate and consumables consumption, and ensures the quality and aesthetics of the surfacing layer. In addition, the precise four-axis control system 5 makes the process have good repeatability, can realize automated mass production, effectively save time and labor costs, reduce production costs, and improve overall production efficiency.

[0029] In order to avoid interference when welding at the bend, special attention should be paid when writing the program. The solution is that when the four-axis CNC system 5 controls the rotary blade 100 to flip, it will also control the welding gun 22 to rise appropriately along the Z axis to reserve a gap for the coating. After the flipping platform 43 is flipped, the welding gun 22 will move forward and move down to re-weld the flipped place, so as to achieve the purpose of stabilizing the entire coating continuous process.

[0030] In this embodiment, in S1, when the welding gun 22 passes through the bending part of the rotary blade 100, according to the bending angle of the rotary blade 100, the motor 41 is controlled to rotate twice to drive the flip platform 43 to drive the rotary blade 100 to flip, and the coating thickness is reserved to avoid interference, thereby ensuring the uniformity and quality of the surfacing layer; in S4, it is confirmed that the cooling water circulation of the water tank 24 is normal, and the conductive clamp is clamped in place, thereby ensuring the cooling effect and current stability during the welding process, thereby further improving the accuracy and stability of the surfacing process, and effectively avoiding problems that may occur during the welding process.

Claims

1. A rotary tiller blade surface plasma automatic surfacing device, characterized in that: It comprises a frame (1), a plasma surfacing system (2), a motion adjustment mechanism (3), a flipping mechanism (4) and a four-axis numerical control system (5); The plasma cladding system (2) comprises a plasma cladding machine (21), a welding gun (22), a powder storage device (23), a water tank (24), an argon gas bottle (25) and a conductive clamp, wherein the plasma cladding machine (21) is connected to the welding gun (22), the powder storage device (23) is connected to the welding gun (22) via a powder conveying pipe, the water tank (24) is connected to the welding gun (22) via a cooling water pipe to form a circulation loop, the argon gas bottle (25) is connected to the plasma cladding machine (21) via an air supply pipe, and the conductive clamp is connected to the plasma cladding machine (21) and is used to be electrically connected to a rotary tiller (100) to form a current loop; The motion adjustment mechanism (3) comprises an X-axis guide rail (31), a Y-axis guide rail (32), and a Z-axis module (33) arranged on a frame (1); the frame (1) is connected to the X-axis guide rail (31), the Y-axis guide rail (32), and the Z-axis module (33) and is used to install a welding gun (22); the four-axis numerical control system (5) controls the X-axis guide rail (31), the Y-axis guide rail (32), and the Z-axis module (33) so that the welding gun (22) moves precisely along the three axes of X, Y, and Z; The turning mechanism (4) comprises a motor (41), a reducer (42), a turning platform (43) and a clamp (44) arranged on the frame (1); the motor (41) drives the turning platform (43) to turn through the reducer (42); the clamp (44) is installed on the turning platform (43) and is used to clamp the rotary tiller (100); and the four-axis numerical control system (5) controls the turning platform (43) so that the rotary tiller (100) turns around a horizontal axis; The plasma surfacing system (2), the motion adjustment mechanism (3) and the flipping mechanism (4) jointly adjust the angle of the rotary blade (100) and the position of the welding gun (22) under the cooperative control of the four-axis numerical control system (5), so as to ensure that the surface of the rotary blade (100) and the welding gun (22) maintain a distance to avoid interference, thereby achieving plasma surfacing on the surface of the rotary blade (100).

2. The automatic plasma surfacing device for rotary blade surface according to claim 1 is characterized in that: The frame (1) is also provided with a screw lifting mechanism (11), the top of the screw lifting mechanism (11) is connected to the motion adjustment mechanism (3), and the four-axis numerical control system (5) is controllably connected to the screw lifting mechanism (11) and can adjust the height of the motion adjustment mechanism (3) along the Z-axis direction.

3. The automatic plasma surfacing device for rotary tiller blade surface according to claim 1 is characterized in that: The plasma cladding machine (21) is provided with an airflow control device, the airflow control device being used to adjust the air supply flow rate, and the welding gun (22) is connected to the argon gas bottle (25) via the airflow control device.

4. The automatic plasma surfacing device for rotary tiller blade surface according to claim 1 is characterized in that: The plasma surfacing system (2) further comprises a secondary cooling device, wherein the secondary cooling device is connected to the welding gun (22) via a cooling pipeline to enhance the cooling capacity of the welding gun (22).

5. The automatic plasma surfacing process for rotary tiller blade surface according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Using a four-axis numerical control system (5) to set the running trajectory of the welding gun (22) according to the surface trajectory of the blade of the rotary tiller (100), generating the coordinates of the trajectory points, and ensuring that when the welding gun (22) passes through the bending area of ​​the rotary tiller (100), the motor (41) is controlled to drive the flipping platform (43) to flip the rotary tiller (100) to avoid interference between the welding gun (22) and the rotary tiller (100); S2. During the movement of the welding gun (22), the welding gun (22) is controlled to perform surfacing welding along the movement trajectory, and at the same time, the welding gun (22) is optimized according to the set parameters of the swing speed, the swing width, and the distance between the gun muzzle and the surface of the rotary blade (100), so as to adjust the coating overlap rate; S3, completing the motion path programming of the welding gun (22) in the four-axis CNC system (5), setting the cycle program, and ensuring the automation and continuity of the cladding process; S4, starting the plasma cladding system (2), adjusting the powder feeding amount and current parameters of the welding gun (22), starting the plasma cladding machine (21) to perform welding operations, and after the cladding is completed, extinguishing the arc and discharging the remaining powder in the powder storage device (23).

6. The automatic plasma surfacing process for rotary tiller blade surface according to claim 5 is characterized in that: In S1, when the welding gun (22) passes through the bending part of the rotary blade (100), the motor (41) is controlled to rotate twice according to the bending angle of the rotary blade (100) to drive the turning platform (43) to drive the rotary blade (100) to turn, and the coating thickness is reserved to avoid interference; in S4, it is confirmed that the cooling water circulation of the water tank (24) is normal and the conductive clamp is clamped in place.

7. The automatic plasma surfacing process for rotary tiller blade surface according to claim 5 is characterized in that: In S4, it is confirmed that the cooling water circulation in the water tank (24) is normal and that the conductive clamp is clamped in place.

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