100吨通用油压机的液压系统设计【含CAD图纸、说明书】
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含CAD图纸、说明书
100吨通用油压机的液压系统设计【含
CAD图纸】
100吨通用油压机的液压系统设计
含CAD图纸
100 吨通用油压机的液压系统设计
100吨通用油压机的液压系统设计【
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毕业设计(论文)评语学生姓名: 学号:学 院: 专业:任务起止时间: 2013 年 2 月 25 日至 2013 年 6 月 16 日毕业设计(论文)题目:100吨通用油压机的液压系统设计指导教师对毕业设计(论文)的评语:指导教师签名: 指导教师职称: 评阅教师对毕业设计(论文)的评语:评阅教师签名: 评阅教师职称: 答辩委员会对毕业设计(论文)的评语:答辩委员会评定,该生毕业设计(论文)成绩为: 答辩委员会主席签名: 职称: 年 月 日教务处制表100吨通用油压机的液压系统设计摘要油压机是一种以液压油为工作介质,根据帕斯卡原理制成的用于传递能量以实现各种工艺的机器。液压机是一种锻压机械,它能完成调直、冷冲压、冷挤压等多种锻压工艺。液压机的结构形式很多,但通常由横梁、立柱、工作台、滑块和顶出机构等部件组成。本文为100T通用油压机液压系统设计,通过对油压机主缸及顶出缸进行工况分析,绘制其速度图和负载图。选择液压基本回路,拟定液压系统原理图,使主缸能完成快速下行、减速压制、保压延时、泄压回程、停止的基本工作循环,顶出缸能实现顶出、退回、浮动压边的动作,之后对液压系统控制过程进行分析。确定液压系统的主要参数,通过对压力、流量等参数的分析与计算,对泵、电机、控制阀等液压元件和辅助件进行了选择。本次设计采用了集成块,除去与泵或液压缸等的连接仍然采用管接头和管道以外,其它各元件之间的连接都通过集成块上的通道,其结构更为紧凑,体积也相对更小,重量也更轻,大大减少管件连接,从而消除了因油管、接头引起的泄漏、振动和噪声,并且液压系统安装 、调试和维护方便,压力损失小,外形美观。另外对液压站进行了总体布局。通过液压系统压力损失和温升的验算,本文液压系统的设计可以满足液压机工作循环的动作要求,能够实现塑性材料的成型加工工艺。关键词 油压机;液压系统;原理图;集成块;液压站The design of 100T hydraulic press hydraulic systemAbstract Hydraulic presses are machines that use liquid as working medium and are made according to the principle of PASCAL to deliver energy to achieve various processes. Hydraulic presses are metal forming machines which can complete various forging technology such as alignment, cold forging, cold extruding and so on. Hydraulic presses have many structural forms but more often than not they are composed of crossbeam, vertical post, work table, slide block and ejector parts. This paper is about the design of 100T hydraulic presss hydraulic system, though the condition analysis of the hydraulic presss main cylinder and ejection cylinder, we can draw their velocity diagrams and load diagrams. Then we choose basic hydraulic circuit to form the hydraulic system schematics. We must make sure the main cylinder can complete the basic working cycle of fast descending, deceleration repression, time delay of press forming, relinef-pressure return and stop, and on the other hand, ejection cylinder can realize the action of ejection, return and floating side pressing. After that, we must analyse the control process of the hydraulic system. Hydraulic systems main parameters are determined and through the analysis and calculation of pressure, flow and other parameters, and then we can go on the choose hydraulic components and auxiliary parts such as pump , motor, filters, control valves. This design adopted the manifold block, and except that the connection of pump and hydraulic cylinder still uses the pipes and pipe joints, the connection of other components all through the channel of the manifold block. Its structure is more compact, volume is relatively smaller, its weight is lighter without pipe connection. Whats more, it can eliminate leakage of tubing, connectors, vibration and noise, also, the installation, commissioning and maintenance of hydraulic systrem are convenient, low pressure drop, and it looks more beautiful.The paper has also designed the overall layout of the hydraulic station.what is more this paper have three-dimensional graph of integrated block, hydraulic pressure station, which make it more beautiful and accessible to reader. The hydraulic system can meet the press order cycle action requires and realize the plastic material forging press, stamping cold extrusion, straightening, bending forming process and other contour machining technic through check calculation of hydraulic system pressure loss and the temperature of the hydraulic system.Key words hydraulic press;hydraulic system;system diagram; manifold block;hydraulic station5目 录摘要IAbstractII第1章 绪论11.1 研究背景11.2 研究目的与意义11.2.1 研究目的11.2.2 研究意义21.3 研究内容2第2章 液压系统设计要求和工况分析32.1 明确对液压系统的设计要求32.2 液压系统的工况分析42.2.1 液压机主缸的工况分析42.2.2 液压机顶出缸的工况分析5第3章 确定液压系统主要参数73.1 确定液压缸的主要参数73.1.1初选液压缸的工作压力73.1.2 确定液压缸的主要结构尺寸73.2 计算系统所需压力83.3 系统流量的计算93.3.1 主缸流量的计算93.3.2. 顶出缸流量的计算10第4章 液压机液压系统原理图设计114.1 系统原理图的设计114.2 液压系统原理图的问题134.3 液压系统的工作原理14第5章 液压元件的选择175.1 确定液压泵及驱动电机的功率175.1.1 确定液压泵的工作压力175.1.2 确定液压泵的最大流量175.1.3 选择液压泵的规格185.1.4 电动机的选择185.2 阀类元件及辅助元件的选择185.3 管道尺寸的确定205.4 油箱容积的确定205.5 系统温升的验算21第6章 液压站结构设计236.1 液压站的结构型式236.2 液压泵的安装方式236.3 液压集成油路的设计236.4 液压油箱的设计24结论27致谢28参考文献29附录30附录Pressure transient theoryBefore embarking on the analysis of pressure transient phenomena and the derivation of the appropriate wave equations,it will be usefull to describe the general mechanism of pressure propagation by reference to the events fllowing the instantaneous closure of a value postioned at the med-length point of a frictionless pipeline carrying fluid between two reservoirs.The two pipeline sections upstream and downstream of the value are identical in all respects.Transient pressure waves will be propagated in both pipes by valve operation and it will be assumed that rate of value closure precludes the use of rigid column theory.As the valve is closed,so the fluide approaching its upstream face is retarded with a consequent compression of the flude and an expansion od the pipe cross-section.The increase in pressure at the valve results in a pressure wave being propagated upstream which conveys the retardation of flow to the column of fluid approaching the valve along the upstream pipeline.This pressure wave travels through the fluid at the appropriate sonic velocity,which will be shown to depend on the properties of the fluid and the pipe material.Similarly,on the downstream side of the valve the retardation of flow results in a reduction in pressure at the valve,with the result that a negative pressure waves is propagated along the downstream pipe which,in turn,retards the fluid flow.It will be assumed that this pressure drop in the downstream pipe is insufficient to reduce the fluid pressure to either its vapour pressure or its dissolved gas release pressure,which may be considerable different.Thus,closure of the valve results in propagation of pressure waves along both pipes and,although these waves are of different sign relative to the steady pressure in the pipe prior to valve operation,the effect is to retard the flow in both pipe sections.The pipe itself is affected by the wave propagation as the upstream pipe swells as the pressure rise wave passes along it,while the downstream pipe contracts due to the passage of the pressure reducting wave.The magnitude of the deformation of the pipe cross-section depends on the pipe material and can be well demonstrated if,for example,thin-walled rubber tubing is employed.The passage of the pressure wave through the fluid is preceded,in practice,by a strain wave propagating along the pipe wall at a velocity close to the sonic velocity in the pipe material.However,this is a secondary effect and,while knowledge of its existence can explain some parts of a pressure-time trace following valve closure,it has little effect on the pressure levels generated in practical transient situations.Following valve closure,the subsequent pressure-time history will depend on the conditions prevailing at the boundaries of the system.In order to describe the events following valve closure in the simple pipe system outlined above,it will be easier to refer to a series of diagrams illustrating conditions in the pipe at a number of time steps.Assuming that valve closure was instantaneous,the fluid adjacent to the valve in each pipe would have been brought to rest and pressure waves conveying this information would have been propagated at each pipe at the appropriate sonic velocity c.At a later time t,the situation is as shown in fig.The wavefronts having moved a distance 1=ct,in each pipe,the deformation of the pipe cross-section will also have traveled a distancel as shown.The pressure waves reach the reservoirs terminating the pipes at a time t=1/c.at this instant,an unbalanced situation arises at the pipe-reservior junction,as it is clearly impossible for the layer of fluid adjacent to the reservoir inlet to maintain a pressure different to that prevailing at that depth in the reservoir.Hence,a restoring pressure wave having a magnitude suffcient to bring the pipeline pressure back to its value prior to valve closure is transmitted from each reservoit at a time 1/c.For the upstream pipe,this means that a pressure wave is propagated towards the closed valve,reducing the pipe pressure to its original value and restoring the pipe cross-section.The propagation of this wave also preduces a fluid flow from the pipe into the reservoir as the pipe ahead of the moving wave is at a higher pressure than the reservoir.Now,as the system is assumed to be frictionless,the magnitude of this reversed flow will be the exact opposite of the original flow velocity,as shown in fig.At the downstream reservoir,the converse occurs,resulting in the propagation of a pressure rise wave towards the valve and the establishment of a flow from the downstream reservoir towards the valve.For the simple pipe considered here,the restoring pressure waves in both pipes reach the valve at a time 21/c.The whole of the upstream pipe has,thus,been returned to its original pressure and a flow has been established out of the pipe.At time 21/c,as the wave has reached the valve,there remains no fluid ahead of the wave to support the reversed flow.A low pressure region,therefore,forms at the valve,destroying the flow and giving rise to a pressure reducing wave which is transmitted upstream from the valve,once again bringing the flow to rest along the pipe and reducing the pressure within the pipe .It is assumed that the pressure drop at the valve is insufficient to reduce the pressure to the fluid vapour pressure.As the system has been assumed to be frictionless,all the waves will have the same absolute magnitude and will be equal to the pressure increment,above steady running pressure,generated by the closure of the valve.If this pressure increment is h,then all the waves propagating will beh,Thus,the wave propagation upstream from the valve at time 21/c has a value-h,and reduces all points along the pipe to h below the initial pressure by the time it reachs the upstream reservoir at time 31/c.Similarly,the restoring wave from the downstream reservoir that reached the valve at time 21/c had established a reversed flow along the downstream pipe towards the closed valve .This is brought to rest at the valve,with a consequent rise in pressure which is transmitted.downstream as a +h wave arriving at the downstream reservoir at 31/c,at which time the whole of the downstream pipe is at pressure +h above the initial pressure whth the fuid at rest.Thus,at time 31/c an unbalanced situation similar to the situation at t=1/c again arises at the reservoir pipe junctions with the difference that it is the upstream pipe which is at a pressure below the reservoir pressure and the downstream pipe that is above reservoir pressure .However,the mechanism of restoring wave propagation is identical with that at t=1/c,resulting in a-h wave being transmitted from the upstream reservior,which effectively restores conditions along the pipe to their initial state,and a+h wave being propagated upstream from the downstream reservoir,which establishes a flow out of the downstream pipe.Thus,at time t=41/c when these waves reach the closed valve,the conditions along both pipes are identical to the conditions at t=0,i.e.the instant of valve closure.However ,as the valve is still shut,the established flow cannot be maintained and the cycle described above repeats.The pipe system chosen to illustrate the cycle of transient propagation was a special case as,for convenience,the pipes upstream and downstream of the valve were identical.In practice,this would be unusual.However,the cycle described would still apply,except that the pressure variations in the two pipes would no longer show the same phase relationship.The period of each individual pressure cycle would be 41/c,where I and c took the appropriate values for each pipe.It is important to note that once the valve is closed the two pipes will respond separately to any further transient propagation.The period of the pressure cycle described is 41/c.However,a term ofen met in transient analysis is pipe period,this is defined as the time taken for a restoring reflection to arrive at the source of the initial transient propagation and,thus,has a value 21/c.In the case described,the pipe period for both pipes was the same and was the time taken for the reflection of the transient wave propagated by valve from the reservoirs.From the description of the transient cycle above,it is possible to draw the pressure-time records at points along the pipeline.These variations are arrived at simply by calculating the time at which any one of theh waves reaches a point in the system assuming a constant propagation velocity c.The major interest in pressure transients lies in methods of limiting excessive pressure rises and one obcious method is to reduce valve speeds.However,reference to fig.illustrates an important point no reduction in generated pressure will occur until the valve closing time exceeds one pipe period.The reduction in peak pressure achieved by slowing the valve before a time 21/c from the start of valve closure and,as no beneficial pressure relief can be achieved if the valve is not open beyond this time.Generally,valve closures in less than a pipe period are referred to as rapid and those taking longer than 21/c are slow. In the absence of friction,the cycle would continue indefinitely.However ,in practice, friction damps the pressure oscillations within a short period of time .In system where the frictional losses are high,the neglect of frictional effects can result in a serious underestimate of the pressure rise following valve closure.In these case,the head at the valve is considerably lower than the reservoir head.However,as the flow is retarded,so the frictional head loss is reduced along the pipe and the head at the valve increase towards the reservoir value.As each layer of fluid between the valve and the reservoir is brought to rest by the passage of the initial +h wave so a series of secondary positive waves each of a magnitude corresponding to the friction head recoverd is transmitted toward the valve,resulting in the full effect being felt at time 21/c.As the flow reverses in the pipe during time 21/c to 41/c,the opposite effect is recorded at the valve because of the re-establishment of a high friction loss,these variations being shown by lines AB and CD.In certain cases,such as long distance oilpipelines,this effect may contribute the larger part of the pressure rise following valve closure.In addition to the assumptions made with regard to friction in the cycle description,mention was also made of the condition that the pressure drop waves at no time reduced the pressure in the system to the fluid vapour pressure.If this had occurred,then the fluid column would have separated and the simple cycle described would have been disrupted by the formation of a vapour cavity at the position where the pressure was reduced to vapour level.In the system described,this could happen on the valves downstream face at time 0 or on the upstream face at time 21/c.The formation of such a cavity is followed by a period of time when the fluid column moves under the influence of the pressure gradients between the cavity and the system boundaries.The period is normally terminated by the generation of excessive pressure on the final collapse of the cavity.This phenomena is generally referred to as column separation and is frequently made more complex by the release of dissolved gas in the vicinity of the cavity.Pressure transient propagation may be defined in any closed pipe application by two basic equations,namely the equations of motion and continuity applied to a short segment of the fluid column.The dependent variables are the fluids average pressure and velocity at any pipe cross section and the independent variables are time and distance,normally considered positive in the steady flow direction.Friction will be assumed proportional to velicity squared and steady flow friction relationships will be assumed to apply to the unsteady flow cases considered.压力冲击现象在着手分析压力冲击现象和化分合理的流体方程之前,去描绘一般的关于压力传递的机械理论。通过参与这个关于阀门定位在一个较长点几乎没有摩擦的管道传输液体于两个蓄能源之间的结果之后是必要的。这个阀门连接的顺流管道截面和逆流管道截面考虑是一样的。压力冲击流将通过阀门操作传递在两个管道之间,并且假设阀门的关闭速度不应用于坚固圆管理论。如果阀门是关闭的,而液体的流向是逆方向的,缓慢前进,结果导致液体被压缩和管道的横截面膨胀。阀门的压力增加导致高压液体逆向流动,延长了液体流过圆管通向阀这段管道的时间。这种高压液体的流动类似声音的传播,是依靠液体和管道材料作为介质的。同样,阀的顺流面流动的延迟,将导致减小压力在阀门处。这个结果否定了高压液体的流动是沿着顺流管道的,阻止液体流动,假设流体压力在顺流管道是不能减小液体压力的或者蒸汽压力或者溶解气体释放的压力,各种愿意的考虑是不同的。这样,关闭着的阀门导致高压液体的流动是沿着管道的,尽管那些流动有着各种不同的征兆。相对于稳定的压力流经阀门开启的管道。这种影响是关于液体流动的延迟在两种管道截面之间,管道自身受到影响由于液体逆向产生高压,管壁膨胀。同时,顺流管道缩短,由于流经液体的压力降低,这种管道横截面的巨大变形是由于管道材料的,并且能够被证明。例如,使用薄壁型橡胶管材。高压液体沿着液流前进。实践证明,由于液体的张力流向沿着管壁,它的速度接近于声速。在这种管道材料中,然而,这是一种次要作用,当认识到它的存在,能够解释一部分压力的传递时间随着阀门关闭特点,它几乎没有影响到压力标准应用在压力冲击现象。在阀门关闭之后,这时是受压时间将主要依靠系统的边界条件,为了描绘阀门关闭的结果在同一个系统上,它将很容易说明在大量的图表上面,管道在每个时间段的情形。由于阀门的关闭是瞬时的,液体接近每一段管道的阀门会带来停止,并且高压液体流动情况可能已经流过每一段管道。在适应的流速c和一段时间t,这时液体已经流过了一段距离1=ct,在每一段管道内,这时管道的横截面是变形也有一段距离1。高压液体到达蓄能站通过管道的时间为t=1/c,在这段距离中出现了一个不稳定的位置,是在管道与蓄能站连接处。由于是不可能出现层流在蓄能站连接处,而保持压力不同及其它的值在阀门关闭之前,流过每一
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