Following ultrasonic-milling composite efficient electric arc material increasing method and device

Abstract

The invention discloses an accompanying ultrasonic-milling composite efficient electric arc material increasing method and device.The device comprises a five-axis linkage planer type milling machine, an ultrasonic milling device is arranged on the planer type milling machine, two six-degree-of-freedom inverted hanging robots are installed on the planer type milling machine, and the six-degree-of-freedom inverted hanging robots are arranged around a milling head of the planer type milling machine; the upside-down hanging robot is provided with an electric arc additive manufacturing set and an ultrasonic peening device. According to the method, the difficulty of milling of complex parts and the defects of the electric arc additive technology in the aspects of size, shape and the like are overcome. By means of the device, the additive manufacturing process and the subtractive manufacturing process can be independently carried out and can be formed at the same time in different areas. And meanwhile, an ultrasonic device can act on the blank body in the material increasing and decreasing processes, and the effects of refining crystal grains and improving the mechanical property of a printed piece material are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of additive manufacturing, and relates to a traveling ultrasonic-milling composite high-efficiency arc additive method and device. Background Art

[0002] Arc additive manufacturing uses arc heat to melt metal wires and forms metal parts according to the principle of stacking discrete materials layer by layer. Arc additive and subtractive composite manufacturing technology takes into account the advantages of arc additive manufacturing technology and subtractive manufacturing technology. It can obtain high-precision and high-quality mechanical parts with high material utilization and high efficiency, and has irreplaceable advantages in manufacturing complex metal components.

[0003] However, arc additive manufacturing is carried out in the form of high-temperature liquid metal droplet transfer. The presence of a liquid molten pool during the forming process makes it difficult to control the edge shape and overall size of the parts, resulting in poor dimensional accuracy and surface quality of the formed parts.

[0004] At present, in order to solve the above problems, patents CN104384936, CN105414981, CN105290789, etc. integrate the end of the arc additive manufacturing equipment into the CNC milling spindle to realize the alternating manufacturing of additive and subtractive materials, which can partially solve the difficulty of secondary processing and clamping of parts. However, there is inaccurate positioning, and the dimensional accuracy and surface quality of the formed parts are poor. For some parts with complex internal structures, it is difficult for the tool to process them in place. The German DMG company combines laser melting deposition technology with a five-axis CNC milling machine, which can greatly improve the accuracy of laser additive manufacturing, and the results are remarkable. However, the size of the metal parts that can be adapted is relatively small. In addition, the patent (CN105574254) proposes a method for realizing additive and subtractive composite manufacturing with a single robot, which effectively expands the size of the formed parts, but the forming efficiency is still low. Summary of the invention

[0005] In view of the above shortcomings, the present invention provides a mobile ultrasonic-milling composite high-efficiency arc additive manufacturing group, which aims to solve the problems of poor dimensional accuracy and surface quality of parts processed by existing additive manufacturing technology, and the difficulty in fine processing of large-format complex parts.

[0006] In order to achieve the above object, the present invention provides the following solutions:

[0007] On the one hand, the present invention provides a portable ultrasonic-milling composite high-efficiency arc additive manufacturing group, including: an arc additive manufacturing group, a gantry milling machine, an ultrasonic milling device, an inverted robot, and a workbench.

[0008] The arc additive manufacturing group includes: robot controller, welding machine, welding machine controller, wire feeder, shielding gas cylinder, inverted robot, welding gun. The robot controller controls the movement of the inverted robot, and the welding gun is installed on the inverted robot;

[0009] Preferably, the welding gun type is MAG;

[0010] Preferably, the shielding gas is a mixture of argon and carbon dioxide;

[0011] Inverted robots are located on both sides of the milling head of the gantry milling machine and control the movement of the welding gun for arc addition. The inverted robots are controlled by a robot control device. The two robots divide the work according to the different characteristics of the parts. The forming trajectory of each robot is reasonably planned according to the complexity of the work tasks and characteristics to achieve the highest efficiency of the inverted robots.

[0012] Preferably, the inverted robot is a six-degree-of-freedom inverted robot, quantity: 2;

[0013] The ultrasonic impact device is fixed on the inverted robot;

[0014] Preferably, the power of the ultrasonic impact device is 1kw, the vibration frequency is 40Khz, and the amplitude is 100um;

[0015] The gantry milling machine is a five-axis linkage gantry milling machine;

[0016] The workbench is located at the lower side of the gantry milling machine, and the arc additive manufacturing group and ultrasonic milling device perform additive and subtractive work on the workbench;

[0017] The ultrasonic milling device comprises: an ultrasonic generator, an ultrasonic transducer, a horn and a milling cutter.

[0018] The principle of the ultrasonic milling device of the present invention is as follows: the ultrasonic generator converts electricity into a high-frequency AC signal, and the ultrasonic transducer receives the AC signal and converts it into mechanical energy for the milling cutter to transmit back and forth. At the same time, the amplitude rod can change the amplitude of the milling cutter, improve work efficiency, expand the temperature adaptation range and extend the life of the ultrasonic transducer. The ultrasonic milling device vibrates the blank during the milling process, refines the grains, and improves its surface material properties.

[0019] The ultrasonic device is a USP-G3 high-speed rotary ultrasonic machining system;

[0020] Preferably, the ultrasonic device current is: 0-200mA, vibration frequency: 20KHZ, amplitude: 4um;

[0021] On the other hand, the present invention provides a method for ultrasonic-milling composite high-efficiency arc material addition, the specific steps of which are as follows:

[0022] (1) Use computer CAD software to create a three-dimensional model of the printout with complex features, and use additive manufacturing system software to slice, layer, and plan the path of the three-dimensional model;

[0023] (2) Polish the substrate clean and fix it on the workbench;

[0024] (3) The two inverted robots located around the milling head of the gantry milling machine are controlled by a common robot controller. The two robots divide the work according to the different features of the parts. For prints with simple and uniform structures, the robot controller controls one of the inverted robots to perform additive manufacturing. For prints with complex structures, the software of the additive manufacturing system performs regional stratification of the three-dimensional model of the print and feeds back the stratification information to the robot controller. The robot controller controls the two inverted robots to perform regional additive manufacturing on the prints. The robot controller rationally plans the forming trajectory of each robot according to the complexity of the work tasks and features to achieve the highest efficiency of the inverted robots. At the same time, it sets a safety area for the working areas of the two robots to avoid mutual interference between the two robots.

[0025] (4) An arc additive device is installed on the inverted robot. The arc additive device performs regional collaborative additive manufacturing on the workbench under the control of the inverted robot. During the additive process, an ultrasonic impact device fixed on the inverted robot performs ultrasonic impact treatment on the printed part, and an ultrasonic milling device on the gantry milling machine performs fine processing and repair on the blank. The ultrasonic milling device improves the surface quality of the blank during fine processing. The two can be performed interactively or simultaneously until the production and manufacturing of the entire component is completed.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The device realizes the integration of additive and subtractive materials. First, multiple additive manufacturing inverted robots are used to collaboratively add materials layer by layer in different areas according to needs, and then the gantry milling machine is used to finish the blanks. This not only overcomes the defects of dimensional accuracy and surface quality in the arc additive process, but also overcomes the constraints of milling processing on the complexity of parts, greatly improving the processing efficiency of parts.

[0028] 2. The device is equipped with an ultrasonic impact device on the additive system and an ultrasonic vibration device on the subtractive system. The two devices vibrate the printed parts as needed under the control of the control system, which improves the material properties and surface quality of the printed parts to a certain extent.

[0029] 3. The inverted robot controller of the device communicates with the CNC system of the five-axis linkage gantry milling machine. The two divide the work according to the temperature distribution of the formed blank body without interfering with each other, thus realizing high-efficiency and high-precision movement of the composite manufacturing equipment.

[0030] 4. The multiple inverted robots in this device can give full play to the flexibility and scalability of the additive manufacturing device to meet the manufacturing requirements of the size and complexity of large-scale complex parts.

[0031] 5. The device is easy to operate, has flexible process, high degree of automation and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of a traveling ultrasonic-milling composite high-efficiency arc additive manufacturing group of the present invention.

[0033] Figure 2 It is a schematic diagram of an accompanying ultrasonic-milling composite high-efficiency arc additive manufacturing group arc additive equipment of the present invention.

[0034] Figure 3 This is a schematic diagram of the structure of the ultrasonic milling device.

[0035] Figure 4 This is the schematic diagram of the ultrasonic milling device.

[0036] Figure 5 This is a simple printout diagram.

[0037] Figure 6 Schematic diagram of complex parts.

[0038] Among them, 1-workbench, 2-gantry milling machine, 3-ultrasonic milling device, 3-1 ultrasonic generator, 3-2 ultrasonic transducer, 3-3 amplitude transformer, 3-4 milling cutter, 4-arc additive manufacturing group, 5-ultrasonic impact device, 6-robot controller, 7-welding machine controller, 8-welding machine, 9-wire feeding mechanism, 10-shielding gas cylinder, 11-inverted robot, 12-welding gun, 13-substrate. DETAILED DESCRIPTION

[0039] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0040] The present invention discloses a traveling ultrasonic-milling composite high-efficiency arc additive manufacturing group, such as Figure 1 , as shown in 2, including: an arc additive-subtractive composite system and an arc additive manufacturing group.

[0041] The arc additive-subtractive composite system includes: a workbench, a gantry milling machine, an arc additive manufacturing group, and an ultrasonic milling device. The inverted robot and ultrasonic milling device of the arc additive manufacturing group are mounted on the gantry milling machine, and three-dimensional motion is achieved through the gantry milling machine. The inverted robot carries a welding gun and controls its position to achieve arc additive manufacturing, and the ultrasonic milling device is used for cutting parts formed by additive manufacturing.

[0042] The arc additive manufacturing group includes: robot controller, welding machine, welding machine controller, wire feeder, shielding gas cylinder, inverted robot, welding gun. The robot controller controls the movement of the inverted robot, and the welding gun is mounted on the inverted robot; the inverted robot is located around the milling head of the gantry milling machine and controls the movement of the welding gun for arc additive manufacturing. The ultrasonic impact device is fixed on the inverted robot and vibrates the printed parts during the additive manufacturing process.

[0043] The present invention provides a specific embodiment, specifically an ultrasonic milling device, such as Figure 3 As shown in Figure 4, the ultrasonic milling device includes: an ultrasonic generator, an ultrasonic transducer, a horn, and a milling cutter.

[0044] The working mode of ultrasonic milling device is as follows: the ultrasonic generator converts electricity into high-frequency AC signal, and the ultrasonic transducer receives the AC signal and converts it into mechanical energy for the milling cutter to transmit. At the same time, the amplitude rod can change the amplitude of the milling cutter, improve work efficiency, expand the temperature adaptability range and extend the life of the ultrasonic transducer. The ultrasonic milling device can perform vibration processing while finishing the blank, refine the grain and improve its surface material properties.

[0045] The present invention discloses a method for adding materials by a traveling ultrasonic-milling composite high-efficiency arc, as follows:

[0046] (1) Use computer CAD software to create a three-dimensional model of the printout with complex features, and use additive manufacturing system software to slice, layer, and plan the path of the three-dimensional model;

[0047] (2) Polish the substrate clean and fix it on the workbench;

[0048] (3) The two inverted robots located around the milling head of the gantry milling machine are controlled by a common robot controller. The two robots divide the work according to the different characteristics of the parts. For prints with simple and uniform structures, the robot controller controls one of the inverted robots to perform additive manufacturing. For prints with complex structures, the software of the additive manufacturing system performs regional stratification of the three-dimensional model of the print and feeds back the stratification information to the robot controller. The robot controller controls the two inverted robots to perform regional additive manufacturing on the prints. The forming trajectory of each robot is reasonably planned according to the complexity of the work tasks and characteristics to achieve the highest efficiency of the inverted robots. At the same time, a safety area is set for the working areas of the two robots to avoid interference between the two robots.

[0049] (4) An arc additive device is installed on the inverted robot. The arc additive device performs regional collaborative additive manufacturing on the workbench under the control of the inverted robot. During the additive process, an ultrasonic impact device fixed on the inverted robot performs ultrasonic impact treatment on the printed part, and an ultrasonic milling device on the gantry milling machine performs fine processing and repair on the blank. The ultrasonic milling device improves the surface quality of the blank during fine processing. The two can be performed interactively or simultaneously until the production and manufacturing of the entire component is completed.

[0050] Example 1

[0051] The present invention provides a specific embodiment, which is a device and method for adding materials to a simple printed part by ultrasonic-milling composite high-efficiency arc. The plan view of the simple printed part is as follows: Figure 5 As shown:

[0052] Install and debug the device and fix the substrate on the workbench. Figure 5 The printed part with simple structure shown in the figure, the robot controller rationally plans the forming trajectory of the robot and controls any one of the inverted robots to work, establishes communication between the robot controller and the welding machine controller, and the inverted robot and the welding gun cooperate to perform additive manufacturing on the workbench. The type of welding gun is MAG, the arc current of the welding gun is 170A, the arc voltage is 22V; the diameter of the welding wire is φ1.0mm; the shielding gas of the welding gun is a mixture of argon and carbon dioxide, and the gas flow rate is 20L / min. The inverted robot is equipped with an ultrasonic impact device, the power of the ultrasonic impact device is 1kw, the vibration frequency is: 40Khz, and the amplitude is: 100um. During the additive process, the ultrasonic impact device vibrates the printed part, effectively eliminates the residual stress of the weld, and improves the material performance of the printed part. After forming a single-layer or multi-layer blank body, the robot controller issues instructions to the gantry milling machine CNC system. At the same time, the robot controller measures the temperature of each point of the blank body and feeds it back to the gantry milling machine control system.

[0053] After receiving the instructions from the robot controller and the temperature of each point of the blank, the gantry milling machine control system will plan the path reasonably according to the required size and surface accuracy of the single-layer or multi-layer blank and the temperature of each point of the blank, and move the workbench to the working position of the gantry milling head. Then, when the temperature of each point of the blank reaches the set temperature line, the ultrasonic milling device of the gantry milling machine will fine-process the single-layer or multi-layer blank while performing ultrasonic vibration on it. The device consists of an ultrasonic transducer, an ultrasonic generator, a horn, and a cutting head. While fine-processing the blank, it further optimizes the material performance of the printed part. The parameters of the ultrasonic milling device are as follows: the current of the ultrasonic equipment is: 100mA, the vibration frequency is: 20KHZ, and the amplitude is: 4um; the ultrasonic milling device also trims the upper surface of the blank to prepare for further arc material addition. After the blank is processed, the robot controller commands the inverted robot to perform the next step. The above process is repeated until the entire print is completed. The setting of the temperature line is determined by the processing performance of the material and the life of the tool.

[0054] Example 2

[0055] Another example of a complex additive print in this embodiment is shown in the plan view of the complex print. Figure 6 As shown:

[0056] Install and debug the device and fix the substrate on the workbench. Figure 6 The printed part with simple structure shown in the figure, the robot controller controls two inverted robots, and the two inverted robots perform additive manufacturing in work areas 1 and 2 respectively. According to the assigned work tasks and the complexity of the features, the forming trajectory of each robot is reasonably planned. At the same time, a safe area is set for the working area of ​​the two robots to avoid mutual interference between the two robots. Communication is established between the robot controller and the welding machine controller, and the inverted robot and the welding gun cooperate to perform additive manufacturing on the workbench. The type of welding gun is MAG, the arc current of the welding gun is 180A, the arc voltage is 24V; the diameter of the welding wire is φ1.2mm; the shielding gas of the welding gun is a mixed gas of argon and carbon dioxide, and the gas flow rate is 20L / min. The inverted robot is equipped with an ultrasonic impact device, the power of the ultrasonic impact device is 1kw, the vibration frequency is: 40Khz, and the amplitude is: 100um. During the additive process, the ultrasonic impact device vibrates the printed part, effectively eliminating the residual stress of the weld and improving the material performance of the printed part. After forming a single-layer or multi-layer blank body, the robot controller sends instructions to the CNC system of the gantry milling machine. At the same time, the robot controller measures the temperature of each point of the blank body and feeds it back to the gantry milling machine control system.

[0057] After receiving the instructions from the robot controller and the temperature of each point of the blank, the gantry milling machine control system will plan the path reasonably according to the required size and surface accuracy of the single-layer or multi-layer blank and the temperature of each point of the blank, and move the workbench to the working position of the gantry milling head. Then, when the temperature of each point of the blank reaches the set temperature line, the ultrasonic milling device of the gantry milling machine will fine-process the single-layer or multi-layer blank while performing ultrasonic vibration on it. The device consists of an ultrasonic transducer, an ultrasonic generator, a horn, and a cutting head. While fine-processing the blank, it further optimizes the material performance of the printed part. The parameters of the ultrasonic milling device are as follows: the current of the ultrasonic equipment is: 100mA, the vibration frequency is: 20KHZ, and the amplitude is: 4um; the ultrasonic milling device also trims the upper surface of the blank to prepare for further arc material addition. After the blank is processed, the robot controller commands the inverted robot to perform the next step. The above process is repeated until the entire print is completed. The setting of the temperature line is determined by the processing performance of the material and the life of the tool.

[0058] Application Examples

[0059] This embodiment discloses an example of a device and method for adding large-format parts using a mobile ultrasonic-milling composite high-efficiency arc additive

[0060] For large-format parts, additive and subtractive processes can also be carried out simultaneously, that is, the milling process can be carried out simultaneously at different working positions during the additive process. The formed blank part is moved to the working area of ​​the gantry milling machine head through the workbench, and then the efficient connection between additive manufacturing and milling is achieved according to the control of the temperature line, while the waiting time between additive manufacturing and milling is effectively reduced. At the same time, both additive manufacturing and milling processes are equipped with ultrasonic vibration devices, which will be vibrated during the forming and finishing processes to eliminate residual stress and improve the performance of the printed parts.

[0061] So far, the technical scheme of the present invention has been described in conjunction with the preferred implementation methods shown in the accompanying drawings. However, those skilled in the art should understand that the above implementations are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. The protection scope of the present invention is obviously not limited to these specific implementations. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical schemes after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A portable ultrasonic-milling composite high-efficiency arc additive manufacturing device, characterized in that: include: Arc additive manufacturing group (4), gantry milling machine (2), ultrasonic milling device (3), inverted robot (11), workbench (1); The arc additive manufacturing group comprises: a robot controller (6), a welding machine (8), a welding machine controller (7), a wire feeder (9), a shielding gas cylinder (10), an inverted robot (11), and a welding gun (12); The robot controller (6) is used to control the movement of the inverted robot (11), and the welding gun (12) is mounted on the inverted robot (11); The inverted robot (11) is located around the milling head of the gantry milling machine and controls the movement of the welding gun (12) to perform arc material addition, and the ultrasonic impact device (5) is fixed on the inverted robot (11); The workbench (1) is located at the lower side of the gantry milling machine (2), and the arc additive manufacturing group (4) and the ultrasonic milling device (3) both perform additive and subtractive processing on the workbench (1); The ultrasonic milling device (3) comprises: an ultrasonic generator (3-1), an ultrasonic transducer (3-2), a horn (3-3), and a milling cutter (3-4); The ultrasonic generator (3-1) in the ultrasonic milling device (3) converts electricity into a high-frequency alternating current signal, and the ultrasonic transducer (3-2) receives the alternating current signal and converts it into mechanical energy that can be used for the milling cutter (3-4) to move back and forth and transmits it out; at the same time, the amplitude changer (3-3) can change the amplitude of the milling cutter; The ultrasonic milling device (3) performs vibration processing and grain refinement while finishing the rough blank.

2. The accompanying ultrasonic-milling composite high-efficiency arc additive manufacturing device according to claim 1 is characterized in that: The gantry milling machine (2) is a five-axis linkage gantry milling machine.

3. The accompanying ultrasonic-milling composite high-efficiency arc additive manufacturing device according to claim 1 is characterized in that: The inverted robots (11) are six-degree-of-freedom inverted robots, and there are two of them.

4. The accompanying ultrasonic-milling composite high-efficiency arc additive manufacturing device according to claim 1 is characterized in that: The welding gun (12) is of MAG type.

5. The accompanying ultrasonic-milling composite high-efficiency arc additive manufacturing device according to claim 1 is characterized in that: The gas in the protective gas cylinder (10) is a mixed gas of argon and carbon dioxide.

6. The accompanying ultrasonic-milling composite high-efficiency arc additive manufacturing device according to claim 1 is characterized in that: The power of the ultrasonic impact device (5) is 1kw, the vibration frequency is 40Khz, and the amplitude is 100um.

7. A method based on any one of claims 1 to 6 of the accompanying ultrasonic-milling composite high-efficiency arc material addition device, characterized in that: The specific steps are as follows: Step (1), using computer CAD software to create a three-dimensional model of the print with complex features, and using additive manufacturing system software to slice, layer and plan the path of the three-dimensional model; Step (2), polishing the substrate (13) and fixing it on the workbench (1); Step (3), two inverted robots (11) located around the milling head of the gantry milling machine (2) are controlled by a common robot controller (6) and the two robots perform division of labor according to different features of the parts; Step (4), an arc additive manufacturing group (4) is provided on the inverted robot (11), and the arc additive manufacturing group (4) performs regional collaborative additive manufacturing on the workbench (1) under the control of the inverted robot (11). During the additive process, an ultrasonic impact device (5) fixed on the inverted robot (11) performs ultrasonic impact treatment on the printed part, and an ultrasonic milling device (3) on the gantry milling machine (2) performs fine processing and repair on the blank body.

8. The method according to claim 7, characterized in that The inverted robot controller (6) communicates with the numerical control system of the five-axis linkage gantry milling machine (2), and the two perform division of labor according to the temperature distribution of the formed rough body without interfering with each other, thereby realizing high-efficiency and high-precision movement of the composite manufacturing equipment.

9. The method according to claim 7, characterized in that: For a printed part with a simple and uniform structure, the robot controller (6) controls one of the inverted robots (11) to perform additive manufacturing.

10. The method according to claim 7, characterized in that For printed parts with complex structures, the software of the additive manufacturing system performs regional stratification on the three-dimensional model of the printed part and feeds back the stratification information to the robot controller (6). The robot controller (6) controls two inverted robots (11) to perform regional additive manufacturing on the printed part. The robot controller (6) reasonably plans the forming trajectory of each robot according to the complexity of the work task and characteristics to achieve the work efficiency of the inverted robot (11), and at the same time sets a safety area for the working areas of the two robots to avoid mutual interference between the two robots.

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