【作者】 周永清；

【导师】 王呈方；

【作者基本信息】 武汉理工大学 ， 船舶与海洋结构物设计制造， 2012， 博士

【摘要】 本文综合分析了国内外关于肋骨冷弯数控加工技术的研究动态。在弦线测量法和机械手肋骨冷弯机的基础上,对弯曲角度的实时计算方法、肋骨回弹处理方法和自动划线参数的计算方法进行了研究,提出了检测机构、弯曲模具的改进方法,设计了自动划线装置和机械手肋骨冷弯机控制程序,并对其进行长期的反复试验与不断改进。论文要点如下：通过研究弯曲角度的实时计算方法,实时计算出实际进料处的肋骨弯曲角度θi。与事先计算的理论角度θi的对比,进一步证明弯曲角度实时计算的必要性。弯曲角度的实时计算消除了肋骨进料误差对加工控制角度的影响,提高了数控机械手肋骨冷弯机的加工精度。分析了肋骨加工中的弯曲回弹过程,详细记录弯曲回弹中各个阶段的角度,考虑机器控制中的过冲问题,采用偏移角代替回弹角应用到回弹处理过程,减少了型材弯曲中的反复逼近次数,提高了肋骨加工效率。研究了机械手数控肋骨冷弯机自动划线的参数计算方法。根据型线坐标系统下的划线参数、机械手肋骨冷弯机的安装参数和加工过程中的进料参数,推导检测坐标系中划线参数的计算过程,并分析了采用该方法进行实际划线结果的误差影响因素。结合提出的自动划线装置,能在自动弯曲过程中,将传感器返回的坐标数据进行实时处理,计算出划线装置的工作参数,同时在肋骨的规定部位上,实时打印出肋骨零件号(任意字体)、起点、终点、水线、切口线、流水孔标记等符号标记,使弯曲加工和号料工艺过程一次完成,提高肋骨加工效率。介绍了机械手肋骨冷弯机的机械、液压、电气等组成部分。在此基础上,对检测机构进行了研究,提出的检测机构,能为自动划线装置提供肋骨有关点的坐标数值,为在弯曲加工过程中同时完成号料工作提供数据基础；另外,也使长期以来存在的“钢丝测量影响操作”的问题获得了解决。分析了角钢和T型材在弯曲过程中发生波浪变形的原因,提出了一种弯曲模具设计方案,用于避免这种有害变形,提高了肋骨加工的成形质量。根据数控机械手肋骨冷弯机的控制系统,软硬件组成和特点,开发一套完整的控制软件。介绍了该软件的控制功能,开发环境,软件的自动控制界面与手动控制界面及其操作方法,标定界面及标定的目的、方法和操作步骤,参数设置界面的设置内容和使用方法。分析了实际应用中出现摆动进料时,球扁钢球头跑出模具、球头刮伤,弯曲过程中的不良噪音和型材表面刮伤等现象,找出其原因,改进程序,消除了这些现象,提高了肋骨加工过程的安全性,提高了型材加工的表面加工质量,改善了肋骨冷弯机某些部件的受力情况,延长其使用寿命。本文在理论和工程应用上都有研究进展。在理论上提出了弯曲角度的实时计算方法、自动划线的参数计算方法和弯曲回弹处理方法。在工程应用上,研究的检测机构、弯曲模具、自动划线装置和设计的控制软件已经投入到生产应用,而且控制软件在长期的试验和应用中得到不断的改进。本文的研究结果已经随着数控机械手肋骨冷弯机的应用和推广,广泛应用到船厂肋骨自动加工的实际生产中,为数字造船技术的进步做出了自己的努力。更多还原

【Abstract】 A review on recent advances and trends on CNC frame cold bending technology is presented at the beginning of this thesis. Based on chord-length measuring method and frame cold bending machine, study on the real-time calculating method of bending angle, handling method for the spring back of the frame, and calculating method of automatic marking parameters is carried out. Improving method of detecting unit and bending dies is presented. Automatic making unit and control software for the CNC frame bending machine are designed, and the control software has been repeatedly tested and constantly improved for a long term. The main contents of this thesis are as follow:Study on the real time calculating of bending angle is carried out. With the real-time calculating method, the bending angle θi at the actual feeding position of the frame is worked out. Comparison of this angle with the angle calculated before processing shows that it is necessary to calculate the bending angle in real time. Processing frame with this angle, influence of feeding error is eliminated and the processing precision is improved.The bending and spring back course of the frame while processed is analyzed and the angles at every stage of the course are recorded. Considering that there is a short time from bending stop command is send out to the frame bending machine stop bending action, handling of spring back is carried out with the deviated angle instead of spring back angle, which is used in gradually approaching method. With this new method, the approaching times are obviously decreased and the frame processing efficiency is improved.Study on the calculating method for automatic marking parameters is carried out. According to marking parameters in offset value coordinate system, installing parameters of the frame bending machine and the detecting parameters in detecting coordinate system, the method to work out the marking parameters in detecting coordinate system are deduced. With the method, control software can work out the control parameters needed by the automatic marking apparatus presented according to the detected coordinates, and drive it to mark out the part name with arbitrary font, start line, end line, waterlines, cutting lines, flooding holes etc. at regulated position on frame surface. So, the bending process and marking of the frame is finished at one process course and the efficiency of the frame process is improved.The mechanic, hydraulic and electrical components of frame bending machine are introduced. A new detecting unit is presented. It can provide data for automatic marking during bending process and solve the problem existed for a long time that the steel wire using for detecting impacts the operation. The reasons of the wave distortion happened at the flange plate of bulb and T bar are analyzed, and then a design plan of bending dies to avoid this distortion and improve the shaping equality of the frame process is presented.According to the hardware components and control system of the frame cold bending machine, the control software is developed. And its functions, developing environment, automatic control interface, manual operation interface, calibrating interface and setting interface are introduced. The phenomenon occurred in feed-in process that bulb head runs out of bending dies and is heavily scraped and the phenomenon occurred in bending process that there is heavy noises and the surface of web plate is heavily scraped are analyzed. The reasons of them occurred are found out and the control software is made improvement to eliminate them. So, the safety of automatic process and surface equality of the processed frame are improved, and the radial force acted on the central clamp hydraulic cylinder is reduced.Some reseach advancement about the CNC control of frame bending machine in theory and engineering application are achieved in this thesis. In theory, the real time calculating method of bending angle, the calculating method of automatic marking parameters and the handling method of spring back are presented. In engineering application, the detecting unit, bending dies, automatic marking apparatus and the control software has been put into practical use. And the software has been constantly improved in the long time test and application.Accompanied with the application and popularizing of CNC frame bending machine, the results of this thesis has been widely used to practical production of frame automatic process in shipyards.更多还原