机械工程硕士论文代写:有关自动变速器的设计与研究
目录:
摘要 4-5
Abstract 5
第1章绪论 9-16
1.1课题来源及课题的研究意义 9-10
1.1.1课题来源 9
1.1.2课题的研究意义 9-10
1.2国内外在该方向的研究现状及分析 10-11
1.3系统方案比较分析与设计 11-13
1.3.1液压伺服阀控缸 11-12
1.3.2气动伺服系统 12
1.3.3电气伺服系统 12-13
1.3.4液压伺服变阻尼 13
1.4系统方案的设计 13-15
1.4.1要求模拟的负载特性的简单描述 13-14
1.4.2系统原理组成 14-15
1.5本文的主要研究内容 15-16
第2章阻尼器的设计计算 16-28
2.1系统主要参数的确定 16-18
2.2液压缸尺寸理论计算 18-22
2.3节流阀尺寸设计计算 22-27
2.3.1节流阀形式的选择 22-23
2.3.2节流阀芯阀套尺寸 23
2.3.3阀芯节流口曲线的推导 23-25
2.3.4阀套节流孔的设计 25
2.3.5阀芯节流口形状的数学描述 25-27
2.4本章小结 27-28
第3章液压缸及节流阀的设计 28-45
3.1液压缸的设计 28-33
3.1.1液压缸安全系数的选择 28
3.1.2液压缸承载力的计算 28-29
3.1.3液压缸工作压力的确定 29
3.1.4工作行程的确定 29
3.1.5液压缸结构设计与校核 29-33
3.2节流阀的设计 33-39
3.2.1阀套的壁厚 33-34
3.2.2转阀芯处液动力的分析 34-35
3.2.3阀芯处泄露的计算与分析 35-37
3.2.4转阀芯处由于密封引起的摩擦力与摩擦转矩的计算 37-38
3.2.5转阀芯转动惯量的计算 38-39
3.3管路直径的确定及校核 39-40
3.4机械结构设计 40-44
3.4.1液压缸 41-43
3.4.2液压阀结构 43-44
3.5本章小结 44-45
第4章数学建模及仿真分析 45-67
4.1数学建模 45-50
4.1.1液压缸和节流阀的数学模型 45-47
4.1.2伺服电机驱动阀芯模型 47-48
4.1.3PID控制器 48-49
4.1.4系统整体模型的建立 49-50
4.2待模拟负载数据输入 50-51
4.3仿真模型的建立 51-53
4.3.1液压缸和节流阀仿真模型 51-52
4.3.2系统整体仿真模型的建立 52-53
4.3.3部分参数估算及设定 53
4.4系统整体仿真分析 53-61
4.5液压缸及节流阀快速性分析 61-66
4.5.1流量方程的线性化 61-63
4.5.2对该系统性能的分析 63-66
4.6本章小结 66-67
结论 67-68
参考文献 68-72
致谢 72
机械工程硕士论文代写【摘要】 自动变速器是汽车自动换挡系统的核心部件,其性能的好坏直接影响到汽车行驶的安全性和平稳性,在其开发过程中,需要测试其性能。若在实车上进行测试,测试效果比较好,但成本高,且有一定的安全风险,因此一般通过设计专业的测试装置来测试其性能。国外的测试装置已比较成熟,但在我国仍处于发展阶段,因此我们对其进行了设计和研究。本文主要设计一个被动式变阻尼负载模拟器,机械系统由一个液压缸和一个可变节流阀组成,当外部装置推动液压缸活塞杆运动时,通过伺服电机控制节流阀节流面积,进而控制系统的阻尼,系统就表现出相应地阻碍活塞杆运动的力,即所要模拟的负载力。此负载力是节流口面积和活塞杆运动速度的函数,由于活塞杆的运动规律已经给定,因此只要调节节流口面积的大小就可以输出相应的负载力。通过分析,为了使负载模拟范围满足要求,液压缸采用拟静压支承式液压缸。本文主要内容包括:首先设计了液压缸和节流阀,初定了液压缸及节流阀参数,并对节流口形式作了数学描述,然后对整个系统数学建模,并在此基础上进行仿真分析。设计指标对系统快速性及准确性要求很高,通过仿真分析后确定了系统模型的参数,作为反馈来指导后续的设计工作,并且调试了PID控制器的控制参数,确定了用经典PID控制算法能满足本系统的控制要求。
【Abstract】 For a car, automatic transmission is the core component of the shifting system, and its performance will have a direct impact on vehicle safety and stability, so in its development progress, it is necessary to test its performance. If we do the testing on the vehicle, the results are relatively well, but the cost is high and there is a problem on security, so people design professional testing equipments to test its performance. And the testing devices have been more mature abroad, but in our country, it is still in developing stage, so we had to do some research and design.In this paper, we design a passive variable damping load simulator, The mechanical system includes a hydraulic cylinder and a variable throttle. When the external devices force hydraulic cylinder piston rod to move, the servo motor controls the area of the throttle, thereby controls the damp of the system, and the system will performance a corresponding force,which impedes the movement of the rod, and that is the load force to be simulated. This force has something to do with the moving speed of the piston rod and the area of the throttle. The movement of the rod has been given, so as long as you change the area of the throttle,the system will performance the corresponding force.After detailed analysis, to meet the requirements of the load simulation, I design the cylinder as analogous hydrostatic bearing hydraulic cylinder. Firstly I design the hydraulic cylinder and throttle, account the parameters of them, and make the mathematical description of cutting expenditure. Then I get the mathematical modeling of the whole system and do the simulation. As the design specifications require quick response and high accuracy, and the simulation analysis determines the parameters of the model, which is the guider of later specific design. After debug the PID controller control parameters, it is sure that classic PID algorithm can meet the requirements of the control of system.
【关键词】 自动变速器负载模拟器; 拟静压支承式液压缸; 可变节流阀;
【Key words】 load Simulator of automatic transmission; analogous hydrostatic bearing hydraulic cylinder; variable throttle;