双节距变节距齿形输送链的啮合机理与试验研究

发布时间：2018-07-17 03:35

【摘要】：随着汽车工业的发展，汽车装配线上用的传统链式输送机的性能已经无法满足汽车装配速度和装配质量提高。现有的汽车装配线上的链式输送机均采用双节距滚子输送链作为牵引件和承载件。由于双节距滚子输送链系统自身结构的限制，随着装配速度的提高，噪声大、磨损剧烈、稳定性差以及由于其内节内宽大于零件尺寸导致整线卡机等问题相继出现，严重影响了装配线的装配速度和装配质量。齿形链传动系统具有高速、低噪声、低磨损、高稳定性等诸多优点，被广泛的应用于传动领域，但是由于其自重过大，应用于输送机中时，会造成较大的冲击、噪声和振动，影响输送性能。因此，研究如何降低齿形链的自重，，使其可以应用在链式输送机上，以满足链式输送机对输送速度、位置精度、稳定性和环境友好性等方面的要求，具有重要的理论研究价值和工程应用意义。本文首先介绍了链传动技术与链式输送机在各领域的应用情况以及它们的国内外发展现状，突出强调了输送链在链式输送机中的重要作用，以及链式输送机在国民经济中的重要作用，反映出本文对双节距变节距齿形输送链研究的学术价值和实际工程意义。通过分析齿形链无法应用于链式输送机中的原因，在国内外学者对齿形链研究的基础上，基于传统齿形链的结构，首次提出了适用于链式输送机的双节距变节距齿形输送链的结构。本文首次提出了双节距变节距齿形输送链的结构。该链条具有内-外复合啮合机制，采用对滚式铰链，围链节距是传统齿形链的两倍，工作链板具有三个齿，其中两侧齿为工作齿，中间齿为减磨齿；给出了工作链板、铰链、边板和导板的主要设计参数及其计算方法，且根据工程实际，设计了新型的齿形链连接接头；根据啮合和滚切原理，建立了双节距变节距齿形输送链—单节距齿形链—链轮滚刀—渐开线链轮的啮合设计体系，研究了双节距变节距齿形输送链与渐开线链轮的主要设计参数之间的耦合关系。以节距P=25.4mm，链轮齿数z=38为例，利用CAD软件绘制了二者的图纸，二者围啮良好；制造样链，进行称重试验和拉断试验，对数据整理后发现，在等抗拉载荷条件下，双节距变节距齿形输送链与传统齿形链相比，单位长度质量降低了30%以上。从而，验证了双节距变节距齿形输送链与链轮设计方法的合理性与正确性。成功将内-外复合啮合机制引入到双节距变节距齿形输送链中，深入分析了双节距变节距齿形输送链与渐开线链轮的内-外复合啮合过程，得出了其啮合周期为4z，且可以划分五个阶段：当前链节的内啮合阶段→前一链节的外啮合定位阶段→当前链节悬浮阶段→下一链节的内啮合阶段→当前链节的外啮合定位阶段；利用平面坐标变换原理，建立了双节距变节距齿形输送链系统的啮合数学模型，确定了双节距变节距齿形输送链与渐开线链轮的初始啮合位置、交变位置以及定位位置。在双节距变节距齿形输送链啮合机理研究的基础上，对其结构特性、运动不均匀性和啮合冲击特性进行了理论分析和仿真研究。结果表明：双节距变节距齿形输送链的内-外复合啮合机制、变节距特性和变节圆特性使其多边形效应、运动不均匀性和啮合冲击力与双节距滚子输送链相比均明显降低。在相同的仿真条件下，与双节距滚子输送链相比，其紧边横向波动量降低了24.18%，水平运动速度不均匀性降低了45.61%，从动轮转速不均匀性降低了23.13%，啮合冲击力降低了52.06%。可以推知：双节距变节距齿形输送链的输送位置准确度优于双节距滚子输送链。针对汽车装配线用水平式输送机，建立了双节距变节距齿形输送链的受力情况数学模型，对其运动过程中的静载荷和附加动载荷进行了理论分析，并与双节距滚子输送链进行了对比。结果显示：双节距变节距齿形输送链的静载荷除了包括传统系统的齿形链系统的静力，还包括链条与导轨之间的摩擦力；由于运动不均匀性引起的动载荷明显低于双节距滚子输送链。可以推知：双节距变节距齿形输送链的受力情况优于双节距滚子输送链。利用封闭力流式试验台对双节距变节距齿形输送链系统和双节距滚子输送链系统进行台架试验，对比分析了二者的噪声性能和磨损性能。结果表明：在转速为200r/min，加载2kN时，与双节距滚子输送链系统相比，双节距变节距齿形输送链系统的噪声降低了3.5dB，且随着转速提高，噪声降低量增大；相同转速条件下，双节距变节距齿形输送链系统的噪声波动量为双节距变节距齿形输送链系统的33%左右；经过250h的磨损试验后，双节距变节距齿形输送链的磨损伸长量仅为0.182%，与双节距滚子输送链相比，其磨损伸长率降低了的45.5%。可见：与双节距滚子输送链相比，双节距变节距齿形输送链的噪声低、耐磨损以及具有高稳定性和环境友好性。将双节距变节距齿形输送链安装在汽车装配线用链式输送机上，对其进行了为期40周的现场磨损试验，结构表明：双节距变节距齿形输送链在经过40周的现场磨损后，磨损状况良好，磨损伸长率仅为0.13%，链式输送机运行良好。可以证明其结构的合理性以及应用于链式输送机中的可行性。综上所述，本文研究的双节距变节距齿形输送链与传统齿形链相比,单位长度质量明显降低；与双节距滚子输送链相比,具有更高的位置精度、更高稳定性和环境友好性，适合应用在链式输送机中。本文得到了国家总装部项目“CDX01项目链传动系统降噪”的支持。
[Abstract]:With the development of automobile industry , the performance of traditional chain conveyor used in automobile assembly line has been unable to meet the automobile assembling speed and assembly quality . The chain conveyor on the existing automobile assembly line has many advantages such as high speed , low noise , low wear , high stability and so on .

This paper first introduces the application of chain drive technology and chain conveyor in each field and their development status at home and abroad , highlights the important role of chain conveyor in chain conveyor and the important role of chain conveyor in national economy .

In this paper , the structure of double - pitch variable - pitch tooth - shaped conveying chain is proposed for the first time . The chain has internal - external composite meshing mechanism , which is double the traditional tooth chain , and the working link plate has three teeth , the two side teeth are working teeth , and the middle teeth are friction reducing teeth ;
The main design parameters and calculation methods of working link plate , hinge , side plate and guide plate are given , and a new type of tooth chain connecting joint is designed according to the engineering practice .
Based on the principle of meshing and hobbing , the meshing design system of double pitch variable pitch tooth chain - single pitch tooth chain - sprocket hob - involute sprocket is established , and the coupling relationship between the double pitch variable pitch profile conveyor chain and the main design parameters of the involute sprocket is studied .
After finishing the data , it is found that the quality of the unit length is reduced by more than 30 % compared with the traditional tooth chain , and the rationality and the correctness of the double - pitch variable - pitch tooth - shaped conveying chain and the sprocket design method are verified .

The internal - external composite meshing mechanism of the inner - outer composite meshing mechanism is successfully introduced into the double - pitch variable - pitch tooth - shaped conveying chain , and the internal - external composite meshing process of the double - pitch variable - pitch tooth - shaped conveying chain and the involute sprocket is deeply analyzed , and the meshing period is 4z , and the five stages can be divided into five stages : the inner engagement stage of the current link , the outer engagement positioning stage of the previous link , the inner engagement stage of the next link and the outer engagement positioning stage of the current link ;
Based on the principle of plane coordinate transformation , the meshing mathematical model of double pitch variable pitch tooth profile conveyor chain system is established , and the initial meshing position , alternating position and positioning position of the double pitch variable pitch tooth profile conveying chain and the involute sprocket are determined .

On the basis of the study of the meshing mechanism of the double - pitch variable - pitch tooth - shaped conveying chain , the structural characteristics , the non - uniformity of the motion and the meshing impact are analyzed and simulated . The results show that the cross - section fluctuation of the double - pitch - pitch - pitch tooth - shaped conveying chain is reduced by 24.18 % , the non - uniformity of the moving speed and the meshing impact force are reduced by 24.18 % , the non - uniformity of the moving speed is reduced by 23.13 % , and the meshing impact force is reduced by 52.06 % . It can be concluded that the accuracy of the transmission position of the double - pitch variable - pitch tooth - shaped conveying chain is better than that of the double - pitch roller conveying chain .

Aiming at the horizontal conveyor for automobile assembly line , a mathematical model of the stress condition of double - pitch variable - pitch tooth - shaped conveying chain is established , and the static load and the additional dynamic load in the motion process are analyzed theoretically and compared with the double - pitch roller conveying chain . The results show that the static load of the double - pitch variable - pitch tooth - shaped conveying chain comprises the static force of the tooth - shaped chain system of the traditional system , and also the friction force between the chain and the guide rail ;
Because the dynamic load caused by the non - uniformity of motion is obviously lower than that of the double - pitch roller conveying chain , it can be concluded that the stress condition of the double - pitch variable - pitch tooth - shaped conveying chain is better than that of the double - pitch roller conveying chain .

The results show that the noise of the double - pitch variable - pitch tooth - shaped conveyor chain system is reduced by 3.5dB when the rotating speed is 200r / min , and the noise reduction is increased with the increase of the rotating speed .
Under the same rotating speed condition , the noise fluctuation quantity of the double - pitch variable - pitch tooth - shaped conveying chain system is about 33 % of the double - pitch variable - pitch tooth - shaped conveying chain system ;
After 250h of wear test , the wear elongation of the double pitch variable pitch profile conveyor chain is only 0.182 % , and its wear elongation is reduced by 44.5 % compared with the double pitch roller conveyor chain . It can be seen that the double pitch variable pitch profile conveyor chain has low noise , abrasion resistance and high stability and environmental friendliness as compared with the double pitch roller conveyor chain .

A 40 - week field wear test is carried out to install the double - pitch variable - pitch toothed conveyor chain on the chain conveyor for automobile assembly line . The structure shows that after 40 weeks of field wear , the wear condition is good , the wear elongation is only 0.13 % , the running of the chain conveyor is good . The rationality of its structure and the feasibility of applying it in chain conveyor can be proved .

In conclusion , compared with the traditional tooth - shaped chain , the double - pitch - pitch - pitch - pitch tooth - shaped conveying chain is obviously lower than that of the traditional tooth chain .
Compared with the double - pitch roller conveying chain , the double - pitch roller conveying chain has higher position precision , higher stability and environmental friendliness , and is suitable for being applied in a chain conveyor .

This paper gives the support of " noise reduction of CDX01 project chain drive system " of the project " CDX01 " .
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH233;TH132.45

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