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1.
With the development of high-speed and high-power, the motorcycle vibration from engine become one of the major factors affecting the performances of motorcycle. Elastic suspension structure is adopted between the engine and frame for the vibration during the process of designing a certain type of motorcycle with 200 cc engine in some enterprise.Through optimization of the suspension system performance parameters, inherent frequency of suspension system keeping away from the activated frequency of engine in common use is essential. Isolation performance is improved and the vibration is solved. As a result, the comfort is improved. 相似文献
2.
The vibration is a great obstacle of motorcycle enterprise development. To solve this problem, matching performance technology of the motorcycle is presented in the researches on the general design of the motorcycle. Based on finite element method and vibration theory, matching performance of the motorcycle has been studied, and the international general software MSC. PATRAN/NASTRAN has been used to analyze the best match between the engine and the frame of a type of motorcycle. An effective method has been formed, which can solve the problem of the vibration of the motorcycle essentially, and shorten the development period of motorcycle, reduce the development cost. It has very important theoretical meaning and great value in engineering application for motorcycle enterprise to design products. 相似文献
3.
The study of motorcycle's acoustic signal shows that gears noise take a great proportion on the whole acoustic of motorcycle.So how to control the noiseof gears is very helpful for reducing the whole motor's acoustic.This paper discusses the engine matching with transmission system in reason,primary transmission and gear geometry design parameter & the mend of tooth body(tooth form & tooth direction) how to influence the acoustic of motorcycle.The study shows that the gear transmission System's matching with engine in reason can notable improve the efficiency of motorcycle.In the meaning time the exactly choosing the primary transmission gear geometry design parameter and the mend of primary transmission gear's tooth body can effectively reduce the acoustic of motorcycle.This paper has engineering practice sense. 相似文献
4.
Simulation of regulatory driving cycle for motorcycle on the engine test bench 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Dynamic performance test methods and experiments of motorcycle engine are investigated. The models of clutch, transmission and brake are simulated by changing the resistance torque imposed by the dynamometer to the engine and with the moment of inertia and road resistance data, the model of a 125 mL motorcycle is established on the dynamic engine test bench. On this basis, the road tests are simulated with models of different inertial mass. Compared with the experiments on the drum tester, the results show that when the inertial mass is set to 1.1 times the datum mass of the motorcycle, the deviations of its maximum speed, sliding distance and acceleration time are no more than 3% and the fuel consumption of 100 km is no more than 5% except the speed of 35 km/h. Through driver operational model, the effect of different gear change models on vehicle acceleration performance is studied. Finally, the regulatory driving cycle for motorcycle is implemented on the dynamic bench and the measurements show that it has high ability to accurately control speed. 相似文献
5.
In order to study the vibration characteristics and radiation noise of wind power speed-increase gearbox, a torsional vibration model of wind power speed-increase gearbox is established based on the analysis of supporting stiffness of bearing and contact stiffness of gear pairs. By solving the vibration differential equation with the help of Matlab, the frequency and corresponding vibration mode are obtained. With taking stiffness excitation, error exaction and meshing impact exaction into account, the dynamic finite element model of speed-increase gearbox is set up, and the dynamic response simulation is carried out. Regarding vibration displacement of the nodes on gearbox surface as boundary condition, an acoustic boundary element model of speed-increase gearbox is built. The surface acoustic pressure of gearbox and the radiation noise of field points are solved by the direct boundary element method. The results show that there is a great difference between torsion frequency and excitation frequency of wind power speed-increase gearbox, and so the resonance doesn't occur. The maximum structural noise and radiation noise mainly appear near the double octave of the gears meshing frequency of high-speed grade. 相似文献
6.
An original variable valve timing mechanism with two-mode intake timing parameters is developed according to the structural characteristics of small-medium displacement motorcycle engine. Based on cycle simulation, a cycle simulation model of VVT mechanism for motorcycle engine is created. The control strategy of variable valve timing and lifting running-model are carried out at idle speed low negative load, middle negative load, low speed high negative load and high speed high negative load. It has been proved that the performance of JH125 motorcycle engine can be effectively improved by loading the new type VVT system. 相似文献
7.
CVT刚性联接发动机曲轴轴系结构的扭振分析 总被引：1，自引：0，他引：1
因非道路车辆的特殊结构和成本限制，提出四缸柴油发动机中采用CVT刚性联接曲轴轴系结构。阐述了该新型结构的特征和工作原理，建立了四缸柴油发动机离合式曲轴计算模型和CVT刚性联接曲轴计算模型。通过曲轴前端实验，证明了所建模型和模型参数确定方法的正确性。求解所有计算模型，并对结果进行对比分析。结果表明，CVT刚性联接使曲轴轴系振动波动加大，减振器耗散能增加，各阶共振峰值对应转速低减。对曲轴各拐剪切应力幅度的影响不大，但有高转速工况降低而中低转速剪切应力幅值增加的普遍趋势，CVT端的扭振振幅和剪切应力较大些。综合研究得出结论：非道路车辆低速四缸柴油发动机可以采纳CVT刚性联接曲轴轴系结构。 相似文献
8.
Dynamic characteristic analysis of an all terrain vehicle body 总被引：1，自引：0，他引：1
The body is a key part of all terrain vehicles (ATV). Its dynamic characteristics greatly effect the vibration of the ATV assembly. Simulation and experimental methods are combined to analyze ATV body vibration characteristics. A computer aided design(CAD) model is built using UG4.0. A finite element method(FEM) model of an ATV body and a body with an engine are created using Hypermesh. The FEM model is imported to Msc.Nastran to calculate the free mode. The simulation model is verified by the experimental modal result. The results indicate that after the frame with engine, the first bending mode increases due to the engine increasing the body stiffness, while the first torsion mode decreases due to the engine mass. The effects on the dynamic response of the road and engine excitation are analyzed respectively. Vibration characteristic improvement methods and suggestions regarding the body are provided. 相似文献
9.
In order to investigate the seismic behavior of partially-restrained steel plate shear wall (Steel Plate Shear Wall, SPSW), the effects of partially-restrained connection on the hysteretic behavior, lateral bearing capacity, stiffness, energy dissipation of SPSW with strong and weak steel frame were simulated under low cyclic loading via equivalent strip model that had been verified by experiment. The results show that hysteretic behavior of SPSW has dual characters. The hysteretic curves of SPSW with strong surrounding steel frame become fat, and the hysteretic curves of SPSW with weak surrounding steel frame become narrow. With the increase of the bending capacity of PR connection, the hysteretic curves of SPSW become fat gradually, and the capacity of energy dissipation and lateral bearing increase. However, the effect on lateral stiffness of PR connection of SPSW with strong steel frame is higher than the one with weak steel frame. 相似文献
10.
An original variable valve timing mechanism with two-mode intake timing was developed according to the structural characteristics of small medium displacement motorcycle engine. Based on cycle simulation, the effects of the VVT mechanism structural parameters, control parameters and operational parameters on the engine performance were analyzed by embedding the VVT mechanism operational mode and control strategies in the engine cycle simulation. Optimum design for the late intake valve closing, the valve lift, as well as the switching speed of the VVT system was carried out. It has been proved that power and torque of the JH125 motorcycle engine can be effectively improved by loading the new type VVT system. 相似文献
11.
Sensitivity analysis of motorcycle frames is useful for improving the design success rate. Based on sensitivity analysis theory and using the Monte Carlo and numerical simulation methods, a new 250 type integral motorcycle model was built and dynamic sensitivity analysis conducted. Sensitive design parameters that have great influence on frame vibration were discovered. By modifying the values of sensitive design parameters, the vibration of some measuring points was reduced. This reduction shows that the sensitivity analysis method is reliable and practical, and it can be used in sensitivity analyses of other complicated structures. 相似文献
12.
In order to solve the structural damage identification problem of transmission tower, a two-step identification method based on change rate and dissipation rate of modal strain energy is proposed. The damage location is identified by the change rate of modal strain energy method. Then, the modal strain energy dissipation rate theory is analyzed further by using the element stiffness matrix after injury. As a result, a more accurate damage quantification equation method is introduced. This method requires only several modals of vibration. The numerical simulation results show that this two-step method can find the damage location and damage degree of transmission towers effectively. 相似文献
13.
Facing the complicacies of motorcycle frame and the fact that the motorcycle frame is subjected to ground dynamic loads,considering the interaction between all parts of the motorcycle,the paper takes all these factors into account and builds a detail transient intensity explicit finite element analysis model,to simulate the motorcycle frame''s dynamic intensity time variation during the motorcycle working.The studies indicate: according to the result of transient analysis,the paper joins the characteristic of the motorcycle frame and stress distribution status,can make the transient intensity analysis more accurate and offer some reliable suggestions for dynamic intensity design of motorcycle frame. 相似文献
14.
建立增速齿轮箱动力学分析有限元模型,利用Lanczos法求得齿轮系统的振动模态;以齿轮副时变啮合刚度激励、齿面综合误差激励和轮齿啮合冲击激励为内部作用激励,采用直接积分法求得箱体表面节点的动态响应。选取箱体上12个主要结构参数作为动力学性能优化的设计变量,齿轮箱体积为状态变量,以齿轮箱表面振动加速度的均方根值最小为动力学性能优化的目标函数,利用零阶与一阶优化算法求得最优设计变量。结果表明：优化前后箱体均不产生共振,且满足静力学条件;优化后目标函数减小37.5%,箱体各计算点的振动响应均有较大幅度的减小,最大减小量为54%。 相似文献
15.
As a kind of complex power machinery, diesel engine is being paid more and more attention to its condition monitoring and fault diagnosis technology. In the fault diagnosis field of diesel engine, the technique of signal process, character abstraction and identification method have formed a system, but there is a certain distance away from practical. This paper analyzes the common faults and influencing factor of diesel engine. The principle, characteristic and disadvantage of modern fault diagnosis technology, such as various time-frequency methods based on vibration signal, speed fluctuation method, iron content and spectrometry, grey system theoretical diagnosis method, artificial neural network and expert system fault diagnosis method, were reviewed. The difficulties and the development direction of diesel engine fault diagnosis were put forward in the end. 相似文献
16.
Considering that the transmission system of wind turbine works in complex and changing load environment caused by stochastic wind speed,this paper uses sparse least squares support vector machine(SL-SVM) to simulate wind speed of true wind field,and obtains time-varying wind load caused by stochastic wind speed. The lumped-parameter method is used to develop a dynamic model of planetary gear transmission system of wind turbine coupled with bearing. The model includes the varying wind load,time-vary mesh stiffness of gear pair and time-vary stiffness of rolling element bearing. The numerical method is used to simulate the dynamic performance of planetary gear system of Multibrid Technology Wind Turbine with 1.5 MW rated power. The vibration displacement responses of the transmission system are obtained as well as dynamic meshing force each pair of gear and nonlinear bearing forces. The research can provide a foundation for optimizing dynamic performance and reliable design of gear transmission system of wind generator. 相似文献
17.
体育馆大跨度预应力次梁楼盖竖向振动模态分析 总被引：2，自引：0，他引：2
以重庆市铜梁县新城核心区小学建设项目3#楼（体育馆）工程为背景，对其大跨度预应力次梁楼盖竖向振动模态进行模拟分析，并与实测结果相比较，评价其控制竖向振动舒适度的效果。根据建模思路精确建立的该大跨楼盖有限元模型，其模态分析结果与模态实测结果接近，相对误差约为5%；模拟分析及工程实测结果表明，该大跨楼盖前三阶振型均以竖向振动为主，结构自振基频满足我国现行相关规范的要求，竖向振动舒适度符合标准；与无底板的大跨次梁楼盖相比，增加底板后，其增幅最小的一阶频率增长了19.9%，表明增加底板可有效地控制大跨度预应力次梁楼盖的竖向振动。 相似文献
18.
A novel three-dimensional isolation bearing (3DIB) was proposed, based on respective mechanical characteristic of lead rubber bearing, combined disc springs and rhombic steel plated damper. Firstly, the configuration department and mechanical design methodology was introduced; the horizontal and vertical stiffness and energy dissipation performance test was performed on a full scale three-dimensional isolation bearing, respectively. The results indicated that the proposed three-dimensional isolation bearing has reasonable configuration and explicit mechanical transmission mechanism; appropriate stiffness and energy dissipation performance can be achieved by reasonable design, keeping favorable holistic stability at plentiful horizontal shear displacement. 相似文献
19.
It is very difficult for small and medium sized motorcycle engine to use the combination of closed-loop control electronic fuel injection system and three-way catalytic converter for emission controlling due to the high cost. In order to strengthen emission controlling of the carburetor motorcycle engines, the metering characteristics of carburetor are adjusted, combustion chamber as well as intake and exhaust ducts are further optimized, and secondary air injection system and oxidation type catalytic converter are developed, and moreover a simplified positive crankcase ventilator is employed to eliminate the gas blowby from crankcase. It is verified by test cycle testing that pollutant emissions of the carburetor motorcycle engines can be effectively controlled within the emissions limits by taking the above technical approaches. 相似文献
20.
The paper proposes the design method of robust H controller of vehicle seat suspension system. The dynamic model of seat suspension is developed,and the parameters uncertainties (mass, stiffness, damping) and stochastic vibration are introduced into the model system. Based on stochastic differential theory and Lyapunov functional, a semi controller is designed, and the controller parameters are solved by linear matrix inequality (LMI) which guarantees H performance index. The simulation results in time domain and frequency domain show that the controller designed for parameter uncertainties and stochastic vibration can attenuate the vertical acceleration of suspension system and improve riding comfort of human. 相似文献