﻿ 叶轮加工中心X轴滑座动态特性分析与优化 Dynamic Characteristic Analysis and Optimization of the X Axis Slide of Impeller Machining Center

Mechanical Engineering and Technology
Vol.05 No.03(2016), Article ID:18614,9 pages
10.12677/MET.2016.53025

Dynamic Characteristic Analysis and Optimization of the X Axis Slide of Impeller Machining Center

Da Chen

School of Mechanical and Electrical Engineering, Beijing Information Science and Technology University, Beijing

Received: Aug. 29th, 2016; accepted: Sep. 23rd, 2016; published: Sep. 26th, 2016

ABSTRACT

Impeller as an important part of the Aero-Engine should have a high machining accuracy and quality. The X-axis slide of Aero-Engine impeller dedicated machining center is taken as the research object, which was turned out by a machine tool factory, and its dynamic characteristics are studied by finite element analysis. The weaker part of the X-axis slide is founded according to the analysis of inherent frequency and modal shape, and as to the weaker part, optimization design scheme is put forward to improve the dynamic characteristics of the X-axis slide. This conclusion provides a certain reference to the future optimized design.

Keywords:Machining Center, Inherent Frequency, Dynamic Characteristics

1. 前言

X轴滑座是高速、高精五轴联动铣削加工中心的重要部件，其动态特性直接影响到整个机床的加工精度、稳定性和抗振性，也是决定机床刚度的关键部件。因此运用计算机辅助软件对作模态分析，观察在各阶模态下的振型和固有频率，找出其薄弱结构并作合理的优化对改善加工中心整体的动态特性具有很大的意义 [4] [5] 。

2. X轴滑座结构特点

3. X轴滑座预处理

Figure 1. Impeller

Figure 2. Model of impeller machining center

(a) Before simplification(b) After simplification(a) 简化前 (b) 简化后

Figure 3. Comparison chart of X axis sliding block model before and after simplification

X轴滑座位置关系图如图4所示。分析叶轮加工中心X轴滑座的位置及连接情况，可知：X轴滑座外侧通过导轨–滑块结构与连接，来实现定位及沿X轴方向上的直线运动；X轴滑座内侧通过导轨–滑块结构与Y轴滑座连接，来实现Y轴滑座的定位和沿Y轴方向上的直线运动；另外，电机滑座通过螺栓连接在X轴滑座底部，始终与X轴滑座同步运动。

Figure 4. Position relation of X axis sliding seat

4. X轴滑座静、动态特性分析

X轴滑座的静力分析可得到X轴滑座的最大变形量和位置，而动态特性分析可得到X轴滑座的各阶固有频率及振型图。综合考虑分析结果，可对模型进行优化，以提高其静、动态性能。

4.1. X轴滑座静力分析

1) 静力载荷计算

X轴滑座与电机的位置关系如图5所示，X轴滑座的底部通过螺栓与电机结构连接。由此可知，作用于X轴滑座的载荷主要来源于底部电机结构的重量。经三维分析软件的质量测试模块分析得，载荷F底座 = 1960 N，方向竖直向下。现将载荷施加于X轴底部与电机结构连接处的螺栓等效结合面上，进行静力分析。

2) 静力分析结果

X轴滑座的静力分析结果如图6所示，前侧下端中间位置最大变形量为1.22 μm。

4.2. X轴滑座模态分析

X轴滑座通过导轨–滑块结构分别与、Y轴滑座连接，其中与的连接实现了其在X方向上的运动，与Y轴滑座连接能够对Y轴滑座的运动起到导向作用。X轴滑座模型前处理完成后利用ANSYS Workbench软件的模态分析模块进行分析。

X轴滑座的前3阶频率及振型描述如表1所示，振型如图8所示。

5. X轴滑座模型优化设计

X轴滑座静力分析结果显示，其前侧下端中间位置变形量最大，因此建议增加底部位置的厚度或尺

Figure 5. Relationship between X axis sliding seat and motor position

Figure 6. The total deformation of the static analysis of X axis sliding seat

Figure 7. Sketch map of the name and the coordinate of each position

Table 1. The result of the modal analysis of X axis sliding seat

(a) First order (b) Second order(a) 第一阶 (b) 第二阶 (c) Third order(c) 第三阶

Figure 8. The first three order modal shapes of the X axis sliding seat

5.1. X轴滑座优化前、后分析结果对比

1) 等效应力结果对比

X轴滑座优化前、后的静力分析等效应力结果对比如表2所示，等效应力图如图10所示。

2) 模态分析结果对比

X轴滑座优化前、后模态分析结果对比如表3，模型优化前的振型图参考图8，模型优化后的振型如图11所示。

Table 2. Comparison between the results of before and after optimization of the von Mises of X axis sliding seat

Table 3. Comparison between the results of before and after modification of the modal analysis of X axis sliding seat

(a) Before optimization (b) After optimization(a) 优化前 (b) 优化后

Figure 9. Comparison of X axis sliding seat model before and after optimization

(a) Before optimization (b) After optimization(a) 优化前 (b) 优化后

Figure 10. Equivalent stress diagram of X axis sliding model before and after optimization

(a) First order (b) Second order(a) 第一阶 (b) 第二阶 (c) Third order(c) 第三阶

Figure 11. The vibration model of X axis sliding seat model after optimization

5.2. 优化结果分析

6. 结束语

Dynamic Characteristic Analysis and Optimization of the X Axis Slide of Impeller Machining Center[J]. 机械工程与技术, 2016, 05(03): 209-217. http://dx.doi.org/10.12677/MET.2016.53025

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