基于开放式数控系统的凸轮轴磨削软件研究与开发

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3.0 牛悦 2024-11-19 4 4 2.06MB 65 页 15积分
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摘 要
进入新世纪以来,我国汽车业得到飞速发展。凸轮轴作为汽车发动机的关键
零件之一,其加工质量和加工效率将对我国汽车业产生深远影响。而传统凸轮轴
磨削采用靠模仿型方法,无法满足凸轮轴高精度、高效率、高柔性加工要求。随
着数控技术的飞速发展,将先进的数控技术应用于凸轮轴磨削已成为一种趋势。
本文通过分析凸轮轴磨削原理及其国内外现状,系统地研究了一种凸轮轴切
点跟踪磨削法方法,建立了凸轮轴切点跟踪磨削法运动模型,并采用 MATLAB 软件
进行了仿真和优化,开发了基于开放式数控系统的数控凸轮轴磨削控制软件,并
在某机床厂生产的 MK8332/H 数控凸轮轴磨床上应用。本文主要开展工作如下:
建立了凸轮轴切点跟踪磨削法运动数学模型。结合凸轮轴的工作原理,对比
分析传统磨削方法,针对不同类型的凸轮,采用切点跟踪磨削法,建立了统一的
砂轮架位移和工件旋转角的运动学模型;采用三次样条曲线拟合方法对凸轮轮廓
线离散数据点进行拟合,确保了凸轮轮廓线的加工精度要求;并建立了磨削条件
下的工件旋转轴、砂轮进给轴速度和加速度数学模型。
仿真和优化了凸轮轴切点跟踪磨削法运动数学模型。结合生产实际,在 MATLAB
环境下,建立了某型号的凸轮轴基于切点跟踪磨削法运动数学模型;并对数学模
型进行了仿真,得出了头架、砂轮架在恒线速磨削方式下的速度和加速度曲线图,
理论上分析了影响凸轮轴加工精度的因素;并根据仿真结果,采用分段恒线速磨
削方法对原有模型进行优化,有效避免因速度、加速度超出伺服系统响应性而引
起的磨削质量下降。
开发了完全自主知识产权的数控凸轮轴磨削控制软件。采用 VB6.0 和 MATLAB,
运用 COM 组件技术,实现了基于恒线速原则的切点跟踪法凸轮轴运动数学模型算
法,并采用语言动态链接数据库、NCDDE Sever 技术,在西门子 840D 数控系统上
成功开发了数控凸轮轴非圆磨削控制软件,实现了凸轮轴 NC 程序自动生成、加工
过程仿真分析、砂轮修整补偿、工艺参数保存等功能。
试验、验证工作。成果应用于上海电气集团某机床厂生产的 MK8332/H 数控凸
轮轴磨床,并进行了磨削试验。试验结果表明,使用数控凸轮轴磨削控制软件后,
凸轮转速达到 30r/min,在满足凸轮加工精度的前提下,提高了加工效率,同时验
证基于恒线速原则的凸轮轴切点跟踪磨削法运动数学模型的正确性和软件实用
性,初步实现了提高数控凸轮轴磨床加工精度和效率的目标。
关键词:凸轮轴 切点跟踪磨削 恒线速度磨削 控制软件 磨削试验
ABSTRACT
Since the new century, Auto industry has developed rapidly in China. As one of the
key parts of automobile engine, the processing quality and machining efficiency of the
camshaft will have a far-reaching influence on China's auto industry. Traditional
camshaft grinding method is mould copying, which cannot satisfy the high precision,
high efficiency and high flexible manufacturing requirements of camshaft. Along with
the rapid development of numerical control technology, it will become a trend to apply
advanced numerical control technology in the camshaft grinding.
By analyzing the camshaft grinding principle and its domestic and international
development status, this paper systematically studied a tangential point tracing grinding
method, and established the movement model of tangential point tracing grinding
method. By simulation and optimization with MATLAB, control software was
developed based on open CNC system. That applied on a machine tool plant production
MK8332 / H NC grinder in Shanghai electric group. The main works of this paper is as
follows:
Established the mathematical model of the camshaft based on the tangential point
tracing grinding method. Combining the working principle, contrasting the traditional
grinding method, using tangential point tracing grinding, this paper established of the
kinematics model between grinding wheel displacement and work piece rotation angle.
Contour line discrete points of the camshaft were fitted with the method of three cubic
spline curve. It was established that the velocity and acceleration mathematical model
between work piece axis and grinding wheel feed axis. Simulated and optimized
mathematical model 0f the camshaft tangential point tracing grinding method.
Connecting with the production practice, in the environment of MATLAB, established a
model based on the camshaft tangential point tracing grinding method. Simulated the
mathematical model, it is concluding the speed and acceleration curve between the head
frame and grinding wheel frame in constant linear speed grinding way, and theoretically
analyzed the influence factors of the machining accuracy of camshaft. According to the
simulation results, it optimizes the original mathematical model with method of the
piecewise constant linear speed grinding, effectively avoids quality decreased that
because the velocity and acceleration beyond servo system responsiveness.
It independently develops the NC grinding control software with completely
property rights. It realized camshaft motion mathematical model algorithm base on the
tangential point tracing grinding method with VB6.0 and MATLAB COM components
technology. Using language dynamically link database and NCDDE Sever technology,
successfully developed NC non-circular grinding control software in Siemens numerical
control system on 840D, realizing the camshaft NC program automatically generated
and machining process simulation analysis, grinding wheel dressing compensation,
process parameters of preserving function.
Test and verify work. The result is used in MK8332 / H NC grinding machines,
and has carried on the grinding test. Experimental results showed that, as a result of
using NC grinding control software, the speed reached 30r/min, when precision premise
in satisfying camshaft processing, improved the machining efficiency. And to verify the
movement mathematical model of the camshaft based on tangent point tracing is correct
and the software utility, this paper preliminarily realized target of improving NC
machining super-accurate accuracy and efficiency.
Keywords: Camshaft, Tangential point tracing grinding, Constant
linear speed grinding, Control software, Grinding test
目 录
摘要
ABSTRACT
第一章 绪论.................................................................................................................1
§1.1 凸轮轴磨削技术...............................................................................................1
§1.1.1 传统凸轮轴磨削技术.................................................................................1
§1.1.2 凸轮轴切点跟踪磨削技术.........................................................................2
§1.1.3 国内外凸轮轴磨床概况.............................................................................2
§1.2 课题来源、意义及内容...................................................................................6
§1.2.1 课题来源.....................................................................................................6
§1.2.2 课题研究意义.............................................................................................6
§1.2.3 课题研究内容.............................................................................................7
§1.3 论文结构...........................................................................................................8
第二章 切点跟踪磨削法运动数学模型的研究.........................................................9
§2.1 凸轮轴工作原理及分类...................................................................................9
§2.2 凸轮轴磨削原理.............................................................................................10
§2.3 影响磨削质量的基本参数.............................................................................11
§2.4 凸轮轴切点跟踪磨削法运动数学模型的建立.............................................12
§2.4.1 砂轮中心位移数学模型建立...................................................................12
§2.4.2 凸轮轴离散数据点拟合...........................................................................15
§2.4.3 恒转速磨削数学模型建立........................................................................17
§2.4.4 恒线速磨削数学模型建立........................................................................20
§2.4.5 加速度校验...............................................................................................21
§2.5 本章小结.........................................................................................................22
第三章 凸轮轴切点跟踪磨削法运动模型仿真与优化...........................................23
§3.1 仿真对象..........................................................................................................23
§3.2 MATLAB 简介 ................................................................................................ 24
§3.3 数学模型建立.................................................................................................25
§3.4 凸轮轴切点跟踪磨削法运动数学模型仿真.................................................27
§3.4.1 恒转速磨削数学模型仿真.......................................................................27
§3.4.2 恒线速磨削数学模型仿真.......................................................................30
§3.5 仿真结果分析及模型优化.............................................................................34
§3.6 本章小结.........................................................................................................35
第四章 基于西门子 840D 凸轮轴磨削控制软件的开发........................................36
§4.1 Sinumerik840D 简介 ....................................................................................... 36
§4.2 数控凸轮轴磨削软件的技术支持.................................................................38
§4.3 数控凸轮轴磨削软件的实现.........................................................................39
§4.3.1 操作界面的设计.......................................................................................40
§4.3.2 语言动态链接库的创建...........................................................................42
§4.3.3 磨削软件的嵌入.......................................................................................42
§4.4 数控凸轮轴磨削软件控制算法的实现.........................................................44
§4.5 本章小结.........................................................................................................45
第五章 凸轮轴的磨削实验.......................................................................................46
§5.1 凸轮轴的磨削艺.............................................................................................46
§5.1.1 工件的表面质量.......................................................................................46
§5.1.2 表面质量对于零件使用性能的影响.......................................................47
§5.2 MK8332/H 数控凸轮轴磨床 .......................................................................... 48
§5.3 凸轮轴的磨削试验.........................................................................................50
§5.3.1 实验目的...................................................................................................50
§5.3.2 实验方法与步骤.......................................................................................50
§5.3.3 实验的过程与结果分析...........................................................................51
§5.4 本章小结.........................................................................................................54
第六章 结论与展望...................................................................................................55
§6.1 全文总结.........................................................................................................55
§6.2 研究展望.........................................................................................................55
参考文献.....................................................................................................................57
在读期间公开发表的论文和承担科研项目及取得成果.........................................61
一、论文..................................................................................................................61
二、专利..................................................................................................................61
三、科研项目..........................................................................................................61
致谢.............................................................................................................................62
第一章 绪论
1
第一章 绪论
§1.1 凸轮轴磨削技术
汽车工业是工业发达国家的支柱产业之一,汽车工业的发展关系到国家的经
济命脉。改革开放以来,我国综合国力得到了极大提高,汽车工业的发展也逐步
提升到国家发展战略上。进入新世纪以来,我国汽车工业发展呈现出新态势,轿
车行业取得了长足发展,国产化程度明显提高,涌现了一大批国内自主品牌。与
此同时,随着汽车业的发展,对发动机和及其零部件的质量和生产效率也提出了
更高要求[1]凸轮轴作为发动机的关键部件之一,轮廓精度会对发动机的性能产生
很大的影响,其加工效率和加工质量将直接影响到整个汽车工业的发展[2]因此凸
轮轴磨削技术正变得日益重要。
§1.1.1 传统凸轮轴磨削技术
凸轮轴类零件的磨削加工是一种非圆类磨削,在普通磨床上无法实现,传统
的凸轮轴磨削采用的是靠模仿型加工。其原理是:工件和靠模同时固定安装在一
起,绕头架回转中心同步回转,在靠模的驱动下,摇杆以及装在摇杆上的靠模均
绕摆动中心往复摆动,砂轮作切入运动,这种摆动运动是由靠模的形状进行控制
的,回转运动和摆动运动的合成就是凸轮的外形轮廓。根据靠模仿型加工原理不
难发现凸轮的轮廓精度取决于靠模的精度,经过长时间使用,靠模会出现磨损现
象,进而影响工件的磨削精度[3~6]。因此靠模仿型加工存在以下缺陷[5~7]
(1) 加工效率低,产品更新换代慢。靠模仿型加工首先应当根据设计要求生产
出母凸轮,然后才可以进行批量生产。标准母凸轮生产较为困难,效率低,成本
高,母凸轮的加工精度关系到凸轮生产的加工精度,因此对于母凸轮的加工精度
要求极高。
(2) 靠模易磨损,影响凸轮的加工质量。靠模仿型加工方法凸轮轮廓曲线的精
度是由靠模来保障的,靠模经过长时间使用会出现磨损现象,靠模的磨损使得摇
杆控制砂轮的位置出现偏差,进而影响凸轮的加工精度。
(3) 此种加工方式决定了工件只能以恒角速度旋转方式加工,由于凸轮轮廓表
面上各点是在不断变化的,于是引起各点的磨削线速度会出现剧烈的变化,产生
较大的轮廓误差,波度和烧伤等加工缺陷。由此生产出的凸轮的使用性能大为下
降。
摘要:

摘要进入新世纪以来,我国汽车业得到飞速发展。凸轮轴作为汽车发动机的关键零件之一,其加工质量和加工效率将对我国汽车业产生深远影响。而传统凸轮轴磨削采用靠模仿型方法,无法满足凸轮轴高精度、高效率、高柔性加工要求。随着数控技术的飞速发展,将先进的数控技术应用于凸轮轴磨削已成为一种趋势。本文通过分析凸轮轴磨削原理及其国内外现状,系统地研究了一种凸轮轴切点跟踪磨削法方法,建立了凸轮轴切点跟踪磨削法运动模型,并采用MATLAB软件进行了仿真和优化,开发了基于开放式数控系统的数控凸轮轴磨削控制软件,并在某机床厂生产的MK8332/H数控凸轮轴磨床上应用。本文主要开展工作如下:建立了凸轮轴切点跟踪磨削法运动数...

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作者:牛悦 分类:高等教育资料 价格:15积分 属性:65 页 大小:2.06MB 格式:PDF 时间:2024-11-19

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