Research on Corner Control Strategy of the WEDM

2014 ◽  
Vol 536-537 ◽  
pp. 1452-1455 ◽  
Author(s):  
Qi Hong Huang

Corner machining accuracy has always been one of the important properties of WEDM. In this paper, the reasons for the corner error of the WEDM were discussed. Then the mathematical deflection model of the electrode wire was established. By experimental measurements, the kerf width and the deflection of the electrode wire were obtained. Then the corner control strategy of the WEDM was proposed. Through experiment of the Comparison of corner error between control strategy with corner control and the one without corner control, it shows that the processing accuracy was improved effectively.

2011 ◽  
Vol 130-134 ◽  
pp. 2316-2320
Author(s):  
Ke Zhang ◽  
Zheng Xing Cui ◽  
Li Ya Gai ◽  
Peng Ge ◽  
Dong Gao Cai

NC machine plays an irreplaceable role in the modern manufacturing because of its high machining processing accuracy, quality stable, flexibility. Through using the Renishaw ML10 laser interferometer detect the positioning accuracy and repositioning accuracy of X axis and Z axis of the HTC20 series of NC machine tools. According to the detection result compensate NC system to meet the machining accuracy requirement. The result shows that the error compensation of NC system is a effective method to improve the position accuracy of NC machine.


Author(s):  
Xiaodong Yu ◽  
Weicheng Gao ◽  
Guangpeng Wu ◽  
Wenkai Zhou ◽  
Hongwei Bi ◽  
...  

Background: As the basis of mechanical manufacturing, large-scale machine tools are developing in the direction of improving processing accuracy, load-bearing capacity and rigidity. Hydrostatic thrust bearing, hydrostatic guide and hydrostatic ram are important components of large machine tools, with the continuous improvement of product accuracy requirements, the research on hydrostatic thrust bearing, hydrostatic guide and hydrostatic ram are more important. Objective: This paper introduces the current research on hydrostatic thrust bearing, hydrostatic guide and hydrostatic ram to express the importance of hydrostatic ram in improving the machining accuracy of machine tools. The study aims to lay a foundation for research and development of hydrostatic ram in the future. Methods: Firstly, the hydrostatic bearing technology is introduced. Secondly, the research status of hydrostatic thrust bearing, hydrostatic guide and hydrostatic ram are introduced to provide theoretical basis for improving the processing performance of rest ram. Result: Deformation compensation and thermal deformation compensation of hydrostatic ram have been studied more. Most of study focus on the accuracy of hydrostatic ram, but less on the bearing performance of hydrostatic ram. Conclusion: Breakthroughs have been made in the research on precision control and structural form of the hydrostatic bearing at home and abroad. Most scholars take the ram of Computer Numerically Control (CNC) boring and milling machines as the research object, but there are less research on the ram of vertical lathes. Therefore, the academic circle should pay more attention to the bearing performance of the hydrostatic ram of vertical lathes.


2021 ◽  
Vol 15 ◽  
Author(s):  
Yanling Zhao ◽  
Jiashuo Zhang

Background: Bearing has been widely used in automotive, aerospace, electronics industry, and other fields.Its pre-tightening technology is one of the most critical technologies. It has an important influence on the accuracy, speed, stiffness, and temperature rise of the spindle. Proper pre-tightening force can eliminate bearing clearance and improve machining accuracy and efficiency of machine tools. Therefore, the development trend of bearing pre-tightening mechanism has been paid more and more attention. Objective: In order to improve the processing efficiency and processing accuracy of the bearing system, the structure and function of the bearing pre-tensioning device are continuously enhanced. Methods: This paper retraces various current representative patents relative to the mechanism of bearing pre-tightening. Results: Through the investigation of several patents of bearing pre-tightening devices, the principles and effects of different bearing pre-tightening devices are classified and reviewed. Besides, the future development trend of bearing pre-tightening devices is discussed. Conclusion: The optimization of the bearing pre-tightening device is conducive to improving processing efficiency and quality. A controllable pre-tightening force is the research direction, and more related patents will be invented in the future.


2013 ◽  
Vol 690-693 ◽  
pp. 3271-3274
Author(s):  
Kai Fa Wu ◽  
Tai Yong Wang ◽  
Qing Jian Liu ◽  
Fu Xun Lin ◽  
Ruo Yu Liang

Overcut or speed impact exists in high-speed interpolation of consecutive tiny segments. Because the remaining distance of the current segment does not exactly equal to an interpolation cycle required distance. Taking processing accuracy as a precondition, a new inflection point processing method is proposed to solve this problem. With different solutions of different angles, this method realizes the tiny line continuous processing with high processing quality. And this method needs a small amount of calculation with strong real-time. Error analysis is done and it can meet machining accuracy requirements. Now this method has been applied to engineering practice.


2010 ◽  
Vol 37-38 ◽  
pp. 146-149
Author(s):  
Li Jun Yang ◽  
Xi Nan Dang

This paper introduced some current researches on the corner error in WEDM and put forward the factors that have an influence on the corner error. The deflection of the wire-electrode that has been caused by discharge force, feeding directions of the wire-electrode and radial flops of the guide pulley was analyzed in detail. To minimize corner errors, the energy control strategy and the trace control strategy are presented. Especially in WEDM-HS processing, the methods improving the processing precision are given as follows: Using the over-cutting and retract program, controlling the wire-electrode tension and improving the guiding and allocation parts.


2020 ◽  
Vol 45 (1) ◽  
pp. 1-8
Author(s):  
Marin Gostimirović ◽  
Dragan Rodić ◽  
Milenko Sekulić ◽  
Andjelko Aleksić

Plasma arc cutting (PAC) is an unconventional process widely used in manufacturing of heavy plate products. This work reports on the research results of machining quality of the workpiece in the plasma arc cutting on the low carbon low alloy steel. An experimental investigation of the characteristics of machining accuracy and surface integrity was carried out for basic machining parameters (cutting speed, arc current, arc voltage, plasma gas pressure, stand-off distance and nozzle diameter). The kerf geometry was determined with three accuracy parameters (top kerf width, bottom kerf width and kerf taper angle). The parameters of deviation present due to plasma curvature were defined by drag and pitch of drag line. The surface roughness was determined with two main roughness parameters through scanning the surface topography (roughness average and maximum height of the profile). The surface properties were determined over microstructure in heat affected zone (HAZ). The results show an acceptable machining quality of the PAC, so that this process is an excellent choice for fast and efficient material removal. However, the plasma arc cutting is not suitable for the final machining because of the metallurgical variations in the HAZ.


2011 ◽  
Vol 18 (1-2) ◽  
pp. 355-364 ◽  
Author(s):  
Zhong Luo ◽  
Shuxian Yang ◽  
Yilan Sun ◽  
Hongyi Liu

In this paper, the dynamical performance of polishing robot working in unstructured environment is investigated. Structure mechanism and operating principle of a polishing robot are introduced firstly, and its dynamical model is established. Then, a S-shaped acceleration-deceleration path planning method and a human-simulated intelligent control (HSIC) strategy are proposed. The S-shaped acceleration-deceleration path planning method is to switch the magnitude and direction of the abrupt velocities between motion sections in order to improve the work efficiency, the smoothness of movement and the processing accuracy. The HSIC control strategy is built based on the unstructured environment information measured by ultrasonic sensors, in which the appropriate programs prepared in advance are determined according to the size and sign of both the control error and its change rate. Simulation results show that the intelligent control strategy combining with optimum path planning method are effective to reduce the structure vibration, to improve the stability and the control accuracy of the polishing robot system.


2014 ◽  
Vol 945-949 ◽  
pp. 1669-1672
Author(s):  
Jun Sun ◽  
Xing Liu ◽  
Zhi Xuan Li

Aiming to deal with thermal error of NC machine tool which can cause reduce of machining accuracy, this paper uses an external error compensation which interacts with NC controllers and PMAC multi-axis and then revises the tool path by adding the error tested in real-time by PMAC card. The processing accuracy is improved eventually. This method can compensate machine geometric errors and thermal errors in real-time. Comparing with other methods of error preventing, this method is more effective and affordable.


2020 ◽  
Vol 197 ◽  
pp. 11012
Author(s):  
Giovanni Gaudio ◽  
Lorenzo Dambrosio

The present work focuses on the control strategy concerning the propulsion system of a variable pitch turboprop aircraft. Extremely common solution for the management of the propulsion system of existing variable pitch turboprop aircraft considers a two-lever system for the control of both the turboprop output power and the propeller thrust. Such an approach translates, on one hand into a greater pilot responsibility and, on the other hand, into higher costs in terms of fuel consumption, aircraft maintenance and pilot training. In order to solve these drawbacks, an one-lever system for the control of the variable pitch turboprop aircraft propulsion system has been proposed. The design of this one-lever propulsion control has been carried at first by developing the whole aircraft ecosystem in Simulink© framework and then by implementing the control algorithm of the one-lever system.


2014 ◽  
Vol 1006-1007 ◽  
pp. 581-585 ◽  
Author(s):  
Lei Wan ◽  
Ying Hao Zhang ◽  
Yu Shan Sun ◽  
Yue Ming Li

An autonomous under vehicle (AUV) should have the ability of self-saving and finishing the certain targets when faults occur, which means that an AUV must have the ability of fault-tolerant control. In order to make it possible, one AUV’s fault-tolerant control strategy is made, which is based on the active disturbance rejection control (ADRC). In this paper, the control method in normal and the one in fault are offered respectively. Besides that, one simulation compared with PID control is made. The simulation results show the AUV’s fault-tolerant control strategy based on ADRC can achieve the goal and has better control results to restrain the shock, overshoot and other phenomena caused by disturbance than the strategy based on PID.


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