Design Method of Assembly Accuracy Repeatability of Heavy Duty Machine Tool

2014 ◽  
Vol 800-801 ◽  
pp. 516-520
Author(s):  
Bin Jiang ◽  
Jia Xue Zhao ◽  
Shou Zheng Sun ◽  
Yi Fei Wang ◽  
Ying Li

Focus on the problems that heavy duty machine tool lack of fault samples and process information in repetitive assembly, result in the existing assembly process method can’t meet the repetitive assembly accuracy. According to characteristics of local machine assembly process, propose its assembly repeatability evaluation indexes. Establish the mapping relation among machine performance, assembly accuracy and structure, and built a hierarchical model of assembly process, obtain the process optimal design scheme of assembly accuracy repeatability. Use the multivariate function differential method, propose a calculation method of heavy machine assembly accuracy, and verify applicability of the method, depend on the machine loads and structure criterions, propose heavy machine assembly accuracy repeatability optimization method, example analysis shows that: the servo effect of repetitive assembly accuracy in new process is obvious, simultaneously stress field magnitude and stability of new technology is better than the original, realize effective control of the machine tool assembly accuracy repeatability.

2012 ◽  
Vol 500 ◽  
pp. 608-613 ◽  
Author(s):  
Feng Lan Cheng ◽  
Bin Jiang ◽  
Ying Li ◽  
Min Li Zheng

Geometry constraint and physical constraint change because the structure is complex, tonnage is large, and assembly load is complex on heavy duty machine tool, assembly relation is changed for repeated assembly, then, the assembly accuracy reproducibility and assembly accuracy retentivity decline, which results in the decrease of assembly reliability. According to this problem, the interaction of geometry constraint and physical constraint is discussed in this paper, the influence factors of assembly accuracy reproducibility and assembly accuracy retentivity are respectively analyzed, the establishing, demolition and re-establishing of assembly relation effects assembly accuracy reproducibility, and evolution of assembly relation with time effects assembly accuracy retentivity, which are respectively revealed. Using margin method to evaluate assembly accuracy reliability, the criterion and evaluation method of assembly accuracy reliability is proposed, in order to provide reliable and quantitative criterion for assembly process design, and reasonably set safety margin of geometry constraint and physical constraint, form reliable assembly process, realize that the assembly accuracy is controlled and improved by assembly.


2011 ◽  
Vol 305 ◽  
pp. 442-445
Author(s):  
Feng Lan Cheng ◽  
Feng He Wu

The problem of topology optimization of large spindle box of heavy machine was studied. Based on ICM topology optimization, the parameters topology optimization were changed by sensitivity analysis and the sensitivity parameters were normalized; the topological parameters were modified and removed which judgment based on the sensitivity of the cross-section unit cell in the progress of optimization. Example shown that the integrated optimization method made the structure optimization more intuitive, not only avoided effectively the occurrence of the load strange in the optimization process, but accelerated the convergence speed.


2014 ◽  
Vol 496-500 ◽  
pp. 2672-2678 ◽  
Author(s):  
Li Gang Cai ◽  
Kai Li ◽  
Qiang Cheng ◽  
Zhuo Qi ◽  
Pei Hua Gu

In order to achieve the remanufacturers and utility extension of the old heavy-duty machine tool, an adaptable design method of the heavy machine tool that oriented to the green remanufacturing is proposed in this paper. The guiding ideology of the adaptable design is integrated into the green design and product development. The present status of research at home and abroad is summarized, and then the existing problems are analyzed. Axiomatic design is introduced to be the research principal line and the four design domains are extended to five ones including regeneration domain. By full analysis, the three future research directions including the adaptable modular design, the adaptable platform design and the adaptable interface design of the heavy-duty machine tool, are proactively introduced.


2019 ◽  
Vol 11 (1) ◽  
pp. 168781401880610 ◽  
Author(s):  
Yang Tian ◽  
Zhifeng Liu ◽  
Xinpeng Xu ◽  
Guang Wang ◽  
Qiwei Li ◽  
...  

The quality of heavy-duty machine tool foundations can drastically affect the operating life and working precision of the tool, and the high cost of manufacture has drawn a lot of attention. This article summarized the research status of the relevant literature on the characteristics, vibration isolation, foundation optimization, and quality inspection of heavy-duty machine tool-foundation system, induced the influencing laws of the influencing factors of the system, reviewed the highlights and achievements in the research of heavy machine tool-foundation system at present, and put forward some problems and development directions existing in the research of heavy machine tool-foundation system. It lays a foundation for realizing the judgment of the concrete foundation quality and improving the processing precision and the maintenance of the heavy machine tool.


2013 ◽  
Vol 364 ◽  
pp. 3-9
Author(s):  
Li Gang Cai ◽  
Zhi Liang Wang ◽  
Tie Neng Guo

As super-span cross-rail of NC heavy-duty planer type milling machine tool has a super span and heavy mass,it will deform seriously after installed. Machining an arch camber on X direction sideway in advance is used to compensate for influence caused by its deformation.Finite-element method is used to analysis deformation of super-span cross-rail when working.Multinomial is used to fit deformation curve based on deformation of the X direction sideway of cross-rail when bottom-slide and ram at each position.At the same time this paper takes into consideration of the impact on camber curve as the bottom-slides span brings about 2 deformation curves.A method based on 2 deformation curves is put forward to design and optimize the camber curve. By comparing various camber curves effect on the deformation of milling head,this article proves that the optimization method can effectively reduce the influence of cross-rails deformation on machine tools accuracy.


Author(s):  
Yongsheng Zhao ◽  
Hongchao Wu ◽  
Congbin Yang ◽  
Ligang Cai ◽  
Zhifeng Liu

The motion accuracy of hydrostatic turntable is the key in improving the machining accuracy of heavy-duty machine tool. However, the motion accuracy of hydrostatic turntable depends not only on the offset load but also on the rotating speed of the turntable as well as the profile errors of the guide rails. In this paper, a simulation model is developed to analyze the effect of guide rail profile errors on the motion accuracy of hydrostatic turntable. The reaction forces of preload thrust bearing and hydrostatic circular oil pads are obtained based on the Reynolds equation of the lubricant film. The motion equations of hydrostatic turntable are derived in which the profile errors of two guide rails are considered. The results show that the motion accuracy of hydrostatic turntable can be affected by wavelength, amplitude of profile errors and speed, and offset load of turntable. Finally, the motion accuracy of heavy-duty hydrostatic turntable used in XCKA28105 type turning and milling composite machine tool is obtained by using the presented method. Comparing with the experimental results, the proposed model can be used to predict the machining accuracy caused by the profile errors of guide rails for any heavy-duty hydrostatic turntable.


2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110349
Author(s):  
Huiqiang Guo ◽  
Mingzhe Li ◽  
Pengfei Sun ◽  
Changfeng Zhao ◽  
Wenjie Zuo ◽  
...  

Rotary-wing unmanned aerial vehicles (UAVs) are widespread in both the military and civilian applications. However, there are still some problems for the UAV design such as the long design period, high manufacturing cost, and difficulty in maintenance. Therefore, this paper proposes a novel design method to obtain a lightweight and maintainable UAV frame from configurable design to detailed design. First, configurable design is implemented to determine the initial design domain of the UAV frame. Second, topology optimization method based on inertia relief theory is used to transform the initial geometric model into the UAV frame structure. Third, process design is considered to improve the manufacturability and maintainability of the UAV frame. Finally, dynamic drop test is used to validate the crashworthiness of the UAV frame. Therefore, a lightweight UAV frame structure composed of thin-walled parts can be obtained and the design period can be greatly reduced via the proposed method.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4045
Author(s):  
David Menéndez Arán ◽  
Ángel Menéndez

A design method was developed for automated, systematic design of hydrokinetic turbine rotor blades. The method coupled a Computational Fluid Dynamics (CFD) solver to estimate the power output of a given turbine with a surrogate-based constrained optimization method. This allowed the characterization of the design space while minimizing the number of analyzed blade geometries and the associated computational effort. An initial blade geometry developed using a lifting line optimization method was selected as the base geometry to generate a turbine blade family by multiplying a series of geometric parameters with corresponding linear functions. A performance database was constructed for the turbine blade family with the CFD solver and used to build the surrogate function. The linear functions were then incorporated into a constrained nonlinear optimization algorithm to solve for the blade geometry with the highest efficiency. A constraint on the minimum pressure on the blade could be set to prevent cavitation inception.


2010 ◽  
Vol 37-38 ◽  
pp. 9-13
Author(s):  
Hong Xin Wang ◽  
Ning Dai

A non-iterative design method about high order intermittent mechanisms is presented. The mathematical principle is that a compound function produced by two basic functions, and then one to three order derivatives of the compound function are all zeroes when one order derivative of each basic function is zero at the same moment. The design method is that a combined mechanism is constructed by six bars; the displacement functions of the front four-bar and back four-bar mechanisms are separately built, let one order derivatives of two displacement functions separately be zero at the same moment, and then get geometrical relationships and solution on the intermittent mechanism. A design example shows that this method is simpler and transmission characteristics are better than optimization method.


2021 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Kyungjung Cha ◽  
Seungnam Kim

A comprehensive method which determines the most efficient propeller blade shapes for a given axisymmetric hull to travel at a desired speed, is presented. A nonlinear optimization method is used to design the blade, the shape of which is defined by a 3-D B-spline polygon, with the coordinates of the B-spline control points being the parameters to be optimized for maximum propeller efficiency, for given effective wake and propeller thrust. The performance of the propeller within the optimization scheme is assessed by a vortex-lattice method (VLM). To account fully for the hull/propeller interaction, the effective wake to the propeller and the hull resistance are determined by analyzing the designed propeller geometry by the VLM, coupled with a Reynolds-Averaged Navier-Stokes (RANS) solver. The optimization method re-designs the optimum blade with the updated effective wake and propeller thrust (taken to be equal to the updated hull resistance), and the procedure continues until convergence of the propeller performance. The current approach does not require knowledge of the wake fraction or the thrust deduction factor, both of which must be estimated a priori in traditional propeller design. The method is applied for a given hull to travel at a desired speed, and the optimum blades are designed for various combinations of propeller diameter and RPM, in the case of open and ducted propellers with provided duct shapes. The effects of the propeller diameter and RPM on the designed propeller thrust, torque, propeller efficiency, and required power are presented and compared with each other in the case of open and ducted propellers. The present approach is shown to provide guidance on the design of propulsors for underwater vehicles, and is applicable to the design of propulsors for surface ships.


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