YJ19卷烟机烙铁升降机构的改进

YJ19卷烟机原烙铁升降机构在设计中采用五连杆机构,在气缸的推动下对烙铁进行升降运动并锁紧,在使用过程中,调节气缸活塞杆速度的节流阀工作位置容易变位,使升降机构升降速度出现失控,气缸磨损加快。造成调整节流阀的维修工作频次高,更换气缸维修用时长。重新设计一个由气缸与烙铁机架组成的连杆机构代替原来的四连杆机构,使其结构更加简化、升降运动平稳,降低了维修人员的工作量和减少了维修用时。     

影响配料秤计量准确度的因素分析及提高途径

正一、影响配料秤准确度的因素1.给料控制装置对系统计量准确度的影响配料秤给料控制装置分为槽式振荡器供料和利用螺旋杆供料两种形式。槽式振荡器供料主要由料斗、振荡器、计量箱、传感器、控制系统、执行机构、机架组成。螺旋杆供料由料斗、步进电机、供料螺杆、计量箱、传感器、控制系统、执行机构、机架组成,该装置是通过控制步进电机单位时间驱动脉冲数来实现快慢速加料。从以上给料控制装置的组成来看,下料口     

快开门式压力容器安全联锁装置问题分析及预防措施

快开门式压力容器广泛应用于建材、化工、医药等行业,一旦发生事故将造成较大危害。安全联锁装置是快开门式压力容器重要的安全保护装置。对快开门式压力容器安全联锁装置功能要求进行分析,总结分析常见的硬件和软件问题,并提出有针对性的预防措施,为快开门式压力容器的日常安全管理和使用提供建议。     

RoboCup中型组机器人踢球器设计

 机器人踢球除了要有智能化的决策系统外,还应该有实现决策的终端机构——踢球装置.针对RoboCup中型组机器人比赛利用电磁阀、气缸、储气瓶、控制电路等器件,设计出一种新型踢球机构以解决目前各队机器人出现“高智商低能力”的现况.通过实验和同类对比验证了本设计的可行性和高效性.     

橄榄形枫斗自动缠绕设备开发

改进铁皮枫斗的成型工艺,提高成型温度。缠绕设备由进料机构、卷绕机构、压紧机构和出料机构组成,采用单片机控制控制系统,实现"机器换人"。工作时,将已经脱去约80%水分的石斛段,在约50℃条件下,由进料机构送入卷绕机构,卷曲成型后,再通过压紧机构压紧成型,由压紧杆端部和机架挡板的半球形凹槽将其成型为橄榄形,再由出料机构移出枫斗,制作出传统手工制式的铁皮枫斗形状。     

一种真空室箱体门的压紧机构设计

借用气缸的推拉力,设计了一种新型门压紧机构,代替原来靠人工转动的纯机械式门压紧机构.该机构结构简单,操作方便,省事省力,且制造成本低,使用寿命长.在实际的应用过程中,生产效率提升明显.     

专利信息

塑料拉吹机不等距合模装置(CN2709144Y)塑料拉吹机不等距合模装置包括有机架和安装在机架上的前模板、中模板和后模板。各模板间由导杆相连,在后模板上安装合模气缸,气缸的活塞杆连接能传动机构带动中     

关于小型快开门结构压力容器连锁装置的探讨

开门式压力容器是广泛应用于化工、轻工、纺织、建材和医药卫生等行业的关键设备,该设备能否长期安全地运行直接关系到工厂的生产、效益、以及人身和财产的安全。文章对小型快开门结构压力容器所使用的几种简单快开门联锁装置工作原理和结构特点作了简单介绍。     

袜子腰封自动折纸机构的优化设计

目的 为了解决袜子腰封过程中不同规格纸卡的多次弯折问题,设计一种摆动式自动折纸机构.方法 采用机构设计方法设计齿轮齿条机构和摇杆滑块机构,从而实现对纸卡进行竖折、横折等多次弯折.采用Matlab优化函数库对机构的摇杆、连杆、摆动角度、气缸行程等尺寸参数进行优化;通过分析确定折弯块摆动角度为15°;利用矢量封闭方程与坐标变换求解折纸过程的运动方程.结果 通过SolidWorks的motion插件对摆动式折纸机构进行运动学仿真分析,仿真结果表明,该机构能满足袜子自动折纸的运动要求,运动轨迹与运动方程相匹配.结论 所设计的摆动式自动折纸机构不仅满足折纸功能要求,而且实现了单个机构完成纸卡的多向弯折,为袜子腰封自动化提供了一种适应性更强的折纸新方案.     

全金属超高真空快速关闭阀的设计与制造

全金属超高真空快速关闭阀（简称快阀）是同步辐射装置的重要真空保护元件。它安放在光束线的上游，如因光束线下游发生偶然事故，压力传感器将发出信号触发快阀的驱动电路，使它迅速关闭，以防止大量气体进入储存环，保护整机正常工作。我们的快阀是用弹簧机构在快速反应电磁铁的驱动下关闭阀板的，启开则由气缸提升阀板。本阀可关闭的窗口尺寸为１４ｘ１４０ｍｍ～２。包括电磁铁反应时间在内的全关闭时间为６．４５ｍｓ（其中关闭窗口的时间是２．４２ｍｓ）。在重复启闭５００多次的试验中，快阀在关闭位置时，阀板和阀座间的气体泄漏率不大于０．５ｔｏｒｒ．１／ｓｅｃ。     

大间隙抱合螺纹金属挤压成形机调模锁模机构设计

目的广东科达机电股份有限公司与南昌大学共同研制的金属内腔挤压成形机通过前期的装配、空载运行,现已经进入工业热试验阶段,该金属内腔挤压成形机的锁模调模比较困难。方法设计改进了一种二板机的调模锁模装置,通过不断改进调模锁模程式,使该金属内腔挤压成形机成功实现在工作温度下锁模调模,保证了模具从常温到工作温度下的动态平衡过程中,抱合螺母抱合拉杆。结果在整个在工作过程中,调模锁模器、定位器、拉杆、抱合螺母装置之间成功实现自动调模、锁模、启模等动作。结论验证了该金属挤压成形机的可行性,为下一步的自动化生产试验创造了条件。     

飞秒激光器脉冲重复频率的锁定技术研究

介绍了光纤飞秒激光器脉冲重复频率锁定技术的应用背景及其原理,并设计了一套可快速实现重频锁定的实验装置,最终将激光器的脉冲重复频率锁定到铷原子钟上,使飞秒激光器的脉冲重复频率获得和原子钟同样的稳定度;通过计数器采集锁定后激光器的脉冲重复频率数据,使用Allan方差给出了稳定度评价,对激光器脉冲重复频率锁定前后的稳定度进行了对比。实验证明,自主设计的实验装置可以实现锁定功能,具有很好的实用价值。     

履带牵引式换带装置液压系统动态特性研究

履带牵引式换带装置是一种矿井带式输送机胶带更换装置,为了解其液压系统的动态特性,应用Automation Studio软件对换带装置液压系统进行建模与仿真。在换带装置拉带速度仿真分析中,获得了在30,35,40,45,50 mL/r排量下液压马达的输入流量、转速仿真曲线以及履带底盘的拉带速度。通过对换带装置夹带速度的仿真,说明其液压缸夹紧与松开的时间差异并分析其原因。防溜带机构夹带速度的仿真表明该机构可在0.2 s内夹紧胶带。工业性试验中通过PLC（programmable logic controller,可编程逻辑控制器）采集现场液压系统压力并和仿真压力对比分析。夹带恒压自适应调节保证了在胶带厚度变化的情况下系统压力仍然能保持稳定。自动锁带油缸压力迅速变化确保了胶带更换作业安全进行。结果表明该装置系统响应速度较快,性能稳定,为履带牵引式换带装置的动力和安全性能提供了保障。     

Transient analysis of bang?bang phase locked loops

This work gives insight into the behaviour of second-order bang-bang phase locked loops in the far from lock region. This region, while largely unexplored, is of particular interest as PLL behaviour in this region determines locking time and capture range. By analysing PLL cycle slipping behaviour in this region, the transient response for the system is derived. Expressions for first-order system stability and locking time are also presented.     

Failure analysis of cylinder clamping rods in diesel engines

This article discusses the failure of cylinder clamping rods in single cylinder diesel engines. The AISI 4140 hardened and tempered steel clamping rods were failing after 200–250 h of operation. The fatigue failures initiated at the root of the last thread on the clamping rod that was engaged in a blind hole in the cylinder block. The failures were caused by loose tolerances on the threads that resulted in a non-uniform distribution of load. The load was concentrated on the last threads to engage, thus causing fatigue crack nucleation at the thread root and propagation until the rod broke by overload. Changing the tolerance on the threads virtually eliminated the fatigue problem.     

Microstructure and mechanical properties relations for green bodies compacted from spray dried granules

Alumina granules from three binder systems were spray dried and pressed into bars at varied pressure. Granules are classified as strong, medium and weak as to reflect the different amount of poly(vinyl-butyral) binder and liquid paraffin plasticizer used in the binder system. Mechanical properties of the pressed bars were obtained from a four-point bend test and microstructures were examined using scanning electron microscopy SEM. Strengths and fracture toughnesses are found to increase as a function of compaction pressure, while the calculated effective flaw size is independent of the compaction pressure for all three granule types. Microstructural examination of fracture surfaces revealed that samples compacted at high pressure exhibited more transgranular fracture than samples compacted at low pressure. Evidently, higher pressure had increased the intergranular fracture resistance which correspondingly increased the fracture toughness of the pressed bars. For bars pressed from granules, green body strengths and toughnesses are strongly dependent on the cohesion between pressed granules and not on the effective processing flaw size.     

Simple method for frequency locking of an extended-cavity diode laser

We have developed an extended-cavity tunable diode laser system that has a small linewidth and a large output power (more than 90% of the free-running power) whose operating frequency can be conveniently locked to a transition line of Rb atoms. Based on flat-mirror feedback and frequency self-locking and with weak feedback, we have achieved a continuous frequency detuning range greater than 900 MHz and a short-time linewidth stability of better than 0.4%. By using a two-step locking procedure we not only can lock the laser frequency but also can detune the frequency to any desired value. The locking is quite sturdy and rugged.     

Inadvertent postdialysis anticoagulation due to heparin line locks

Large-bore dual lumen in-dwelling venous catheters are used in hemodialysis. These catheters are usually locked with heparin after the treatment. This study addressed the underappreciated postdialysis coagulopathy that can result. Thirty-six patients were included: 7 dialyzed through arterio-venous fistulae, 29 through in-dwelling venous catheters. The latter group was further subdivided according to whether they received heparin or heparin-free dialysis. To assess the heparin lock, a full-dose heparin lock as well as a much weaker heparin lock and a citrate lock were used. To assess the coagulopathy, blood was taken 1 hr after dialysis. The activated partial thromboplastin time (APTT) and anti-Xa level was measured. Additionally, 6 venous catheters were removed and the amount of fluid expelled upon locking with saline was measured. Clotting from the patient group with arterio-venous fistulae was normal following dialysis. The patients with in-dwelling venous catheters and heparin locks had significantly deranged clotting; 6 out of 10 patients had abnormal APTT results. All patients with catheters, heparin-free dialysis, and heparin locks had deranged clotting (7 out of 7). The rate decreased significantly when heparinized saline was used as a lock. A subset of patients had a citrate lock rather than a heparin lock; the clotting results normalized in all but one patient. An in vitro study demonstrated immediate leakage of fluid from the end of the ports upon locking. Significant postdialysis anticoagulation can occur after dialysis, which can be attributed to the heparin line locks. This risk is considerably reduced when a citrate lock is used instead.     

充液成形设备双闭环控制分析

目的 研究先进充液成形设备的精度控制技术,以满足充液成形过程中对成形介质压力及侧推油缸位置的高精度控制要求,并确保模具型腔的密封性和零件成形的稳定性。方法 基于PLC控制器下的PID闭环控制功能,将速度闭环和位置或压力闭环进行集成,开发应用于液压系统的双闭环控制方法。结果 使用双闭环控制方法,可以调整侧推油缸的位置控制精度及响应速度,并将精度控制在0.1 mm以内,也可调整增压装置的输出端压力控制精度,使精度达到0.3MPa。结论 在利用充液成形设备进行液压成形的过程中,双闭环技术可以实现设备侧向密封的精确位置控制以及型腔内压力的精确控制。     

波浪锥型圆柱流固耦合振动机理研究EI北大核心CSCD

为增强及控制无叶片风力俘能结构能量采集效率,该研究将表面结构斜率参数引入波浪型圆柱,发展了一种新型波浪锥型圆柱,试验研究在雷诺数Re=3900下不同波长比、波幅比、斜率参数的波浪锥型圆柱涡激振动响应特性。研究发现:在不同折合流速下,斜率k=0.05的锥型圆柱和波长比λ/D _(m)=1.75、波幅比α/D _(m)=0.10、斜率k=0.05的波浪锥型圆柱最大振幅较直圆柱分别增长26.4%和12.6%,且锁频区间得以拓展;当折合流速在锁频区间内时,在波浪锥型圆柱绕流尾流中观察到了“2S”、“2P”漩涡脱落模式,并且“2P”漩涡脱落模式在往下游发展的过程中有转变为“2C”模式的趋势。该研究可为无叶片风力俘能结构涡致振动的增大和发电效率的提升提供理论支持。