一种基于宏指令的数控加工进度采集方法

为了解决大型工件数控加工中采集工件加工进度信息比较困难的问题,提出一种基于宏指令数控加工进度采集方法,并在此基础上开发了工件数控加工进度采集系统。该方法定义了一种数控加工进度信息嵌入的规则,加工前通过外部通信宏指令按指定规则在NC文件中嵌入加工进度信息,形成采集系统可识别的加工进度信息的新NC文件;加工时机床通过外部通信宏指令上传工件加工进度信息到本地监控终端,采集系统进行处理、显示,并上传至企业的数据库供相关制造系统调用。进行了试验验证,结果证明:此方法是一种准确、可行的数控加工进度信息自动采集方法。

多信息集成的数控批量加工进度自动采集方法

针对现有批量工件数控加工进度信息采集方法准确度难以保证,返工件数、报废品数等信息难以剔除,采集信息内容单一等问题,在分析加工进度信息构成的基础上,提出基于多源信息集成的批量工件数控加工进度信息自动采集方法。该方法通过采集数控加工启停信号、加工过程实时功率信息和质检信息等多源信息,进行逻辑判断、分析处理和综合集成,获取在加工工件的状态向量;从而可实时自动采集已完工件数、待返工件数、已返工件数、合格件数、报废件数等加工过程中企业和用户都十分关注的多种加工进度信息。在数控滚齿加工中的应用验证表明,所提方法能够准确采集批量加工过程中的多种进度信息,具有较好的应用前景。

数控批量加工进度多信息集成的自动采集方法探讨

随着科技的不断发展,需对产品设计和加工上加大力度,但目前大批量数控加工件数的信息采集很难得到保证,尤其精准度更加难掌控,伴随而来的是报废数、返工数大大增加,由于产品数控加工信息内容过于简单,导致很多问题的发生。随着数控加工慢慢的发展,对加工信息进度提出了很多方案,通过各种方案后进行筛选分析后,选择信息集成的批量工件数控加工进度自动采集,该自动采集方法是通过加工启动讯号、加工过程、加工结束、相关信息参数等进行产品质量检测,同时伴随着逻辑判断和准确分析得到准确数据。通过此次方法可以快速采集加工数、返工数、未完成数、良品数、报废数等企业运营的一些数据,通过本文的详细阐述,该项技术可以准确采集到产品批量加工的详细数据,对未来数控加工有很大帮助。

基于物联网的数控平面磨床远程监控系统设计

引言平面磨床是磨削工件平面或成型表面的一类磨床,是进行精加工保证机械零件最终加工精度和质量的重要设备。平面磨床的故障会导致磨床工作状态改变,降低加工质量,如不及时对故障进行处理,可能会影响加工进度,给企业造成较大的经济损失。因此,对平面磨床运行状态监测和故障报警很有必要,但传统的故障排除只能靠人工在现场通过检查平面磨床的工作状态判断工业生产的状况是否异常。

Prediction of preheating conditions for inclined laser assisted machining

For laser assisted machining,shape of preheating laser heat source is changed irregularly because of complexity of material shape.So,the preheating temperature should be controlled by adjusting the feed rate or the laser power.Thermal analyses of the laser assisted machining process for inclination planes were performed.By analyzing the obtained temperature profile,a proper feed rate control method was proposed according to the inclination angles.In addition,the temperature distribution of the cross section after feed rate control was predicted.The correlation equation between inclination angles and adjusted proper feed rate was proposed.The results of this analysis can be used to predict the preheating effect on workpiece and can be applied as a preheating temperature control method in laser assisted machining processes.

Development of twin wheel creep-feed grinding machine using continuous dressing for machining of aircraft rotary wing

The purpose of this study is to develop a twin wheel creep-feed grinding machine using continuous dressing to machine precise axisymmetric turbine blades that have been difficult to machine using a conventional creep-feed machine.In order to develop such a machine,3D-modeling and machine simulations were performed and a twin wheel creep-feed grinding machine was manufactured.Furthermore,the axisymmetric precision of the machined workpieces through practical machining was evaluated and the quality of the continuous dressing effect of the developed machine was established.In addition,experimental considerations for a proper dresser-to-wheel speed ratio and proper feed rate of the dresser were carried out.As a result,a twin wheel creep-feed grinding machine with continuous dressing is developed through machine simulation,manufacturing and performance evaluation.Optimum condition for the dresser feed rate is 0.3μm/rev.In cases of large dressor-to-wheel speed ratio,grinding efficiency can be enhanced,but the surface roughness shows a conflicting trend.Developed twin wheel creep-feed grinding machine has satisfactory appraisal with regard to surface roughness,flatness,and parallelism.Satisfactory surface roughness below 0.1μm can be obtained for the blade of aircraft.However,in order to perform precise machining,it is necessary to improve the structure of the twin wheel creep-feed grinding machine.

Vibration sensitive admixture for roller compacted concrete

In order to further speed up the construction progress,shorten the rolling time and reduce the rolling times of roller compacted concrete after analyzing work of construction progress improvement measures of roller compacted concrete,research on vibration sensitive admixture is carried out and satisfactory results are acquired.The new type vibration sensitive admixture was used in the project of Jinghong hydropower station in Yunnan Province,China.The engineering experimental results show that various indexes have been verified.Meanwhile,the compactness of roller compacted concrete is improved under the same rolling times,the rolling times and the duration time can be reduced under the same compactness requirement in construction practice.

High speed interpolation for micro-line trajectory and adaptive real-time look-ahead scheme in CNC machining

CNC machining plays an important role in mechanical manufacturing.A key issue is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints of the CNC machine.For the consecutive micro-line segments interpolation,the velocities at the junction of two segments are the bottlenecks for the machining efficiency.This paper proposes a multi-period turning method to improve the feedrate at the junctions using the linear acceleration and deceleration mode,which utilizes the maximal acceleration capabilities of the NC machine while satisfying the machining precision.A new and more efficient look-ahead method and a feedrate override method are also proposed to boast the global machining speed.The proposed algorithm has been implemented on Blue Sky NC System,and experimented in real material manufacturing.Compared with several existing algorithms,the current algorithm can improve the manufacturing time ranging from 50% to 180%,depending on the machining parameters,and also results in better machining quality.In addition,the algorithm also satisfies the need of real-time interpolation.

VARIABLE FEEDRATE INTERPOLATION OF NURBS TOOLPATH WITH GEOMETRIC AND KINEMATICAL CONSTRAINTS FOR FIVE-AXIS CNC MACHINING

Variable feedrate interpolation algorithms for five-axis parametric toolpath are very promising but still rather limited currently.In this paper,an off-line feedrate scheduling method of dual NURBS curve is presented with geometric and kinematical constraints.For a given dual parametric curve,the feedrates of sampling points are first scheduled sequent with confined feedrate of cutter tip and machine pivot,chord error,normal acceleration and angular feedrate.Then,the feedrate profiles of angular feed acceleration sensitive regions of the path are adjusted using a bi-directional scanning algorithm.After that,a linear programming method is used to adjust the feedrate profiles of linear feed acceleration sensitive regions and control the linear feed acceleration of both cutter tip and machine pivot within preset values.Further,a NURBS curve is used to fit the feedrates of sampling points.Finally,illustrative examples are carried out to validate the feasibility of the proposed feedrate scheduling method.The results show that the proposed method has the ability of effectively controlling the angular feed characters of cutter axis as well as the chord error and linear feed characters of cutter tip and machine pivot,and it has potential to be used in high accuracy and high quality five-axis machining.