喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有，請(qǐng)放心下載，文件全都包含在內(nèi)，圖紙為CAD格式可編輯，有疑問咨詢QQ:414951605 或 1304139763p 1Hydraulic actuation system design and computation1clear about the design request to carry on the operating mode analysis.When design hydraulic system below, first should be clear about thequestion, and takes it as the design basis.Main engine use, technological process, overall layout as well as tohydraulic gear position and spatial size request; The main engine to thehydraulic system performance requirement, like the automaticity, the velocitymodulation scope, the movement stability, the commutation pointingaccuracy as well as the request which to the system efficiency, warmpromotes; Hydraulic system working conditions, like temperature, humidity,vibration impact as well as whether has situation and so on corrosiveness andheat-sensitive material existence.In in the above work foundation, should carry on the operating modeanalysis to the main engine, the operating mode analysis including themovement analysis and the mechanical analysis, also must establish the loadand the operating cycle chart to the complex system, from this understood thehydraulic cylinder or the oil motor load and the speed change as necessary therule, below makes the concrete introduction to the operating mode analysiscontent1.1 movements analysesThe main engine functional element according to the technologicalrequirement movement situation, may use the displacement circulation chart(Lt), the speed circulation chart (vt), or the speed and the displacementcirculation chart indicated, from this carries on the analysis to the movementrule.1.1.1 displacements circulation attempts LtThe chart 1.1 is the hydraulic press hydraulic cylinder moves thecirculation chart, the y-coordinate L expression piston moves, the2x-coordinate t expression starts from the piston to the reposition time, the rateof curve expression movement of plunger speed.Chart 1.1 displacements circulation chart1.1.2 speeds circulation chart vt (or vL)In the project the hydraulic cylinder movement characteristic may induceis three kind of types. The chart 1.2 is three kind of types hydraulic cylindersv t chart, the first kind of like chart 1.2 center solid lines show, thehydraulic cylinder starts to make the uniform accelerated motion, thenuniform motion,Chart 1.2 speeds circulation chartFinally uniform retarded motion to end point; The second kind, thehydraulic cylinder preceding partly makes the uniform accelerated motion inthe overall travelling schedule, in another one partly makes the uniformretarded motion, also the acceleration value is equal; The third kind, thehydraulic cylinder one most above makes the uniform accelerated motion inthe overall travelling schedule by a smaller acceleration, then uniformdecelerates to the travelling schedule end point. Vt chart three velocitycurve, not only clearly has indicated three kind of types hydraulic cylindersmovement rule, also indirectly has indicated three kind of operating modesdynamic performance.31.2 mechanical analyses1.2.1 hydraulic cylinders loads and duty cycle chart1.2.1.1 hydraulic cylinders load strength computationsWhen the operating mechanism makes the straight reciprocating motion,the hydraulic cylinder must overcome the load is composed by six partsbmgifcFFFFFFF+=(1.1)In the formula: FcIn order to resistance to cutting; FfIn order to frictiondrag; FiFor inertia resistance; FgFor gravity; FmIn order to seal the resistance;FbIn order to drain the oil the resistance.1.2.1.2 hydraulic cylinders cycle of motion various stages overall loadstrengthThe hydraulic cylinder cycle of motion various stages overall loadstrength computation, generally includes the start acceleration, quickly enters,the labor enters, quickly draws back, decelerates applies the brake and so onseveral stages, each stage overall load strength has the difference.(1) starts the acceleration period: By now the hydraulic cylinder or the pistonwere in from static enough to starts and accelerates to the certain speed, itsoverall load strength including guide rail friction force, packing assemblyfriction force (according to cylinder mechanical efficiency m=0.9computation), gravity and so on item, namely:bmgifFFFFFF+=(1.2)(2) fast stage:bmgfFFFFF+=(1.3)(3) the labor enters the stage:bmgfcFFFFFF+=（1.4）(4) decelerates:bmgifFFFFFF+=(1.5)To the simple hydraulic system, the above computation process maysimplify. For example uses the single proportioning pump to supply the oil,4only must calculate the labor to enter the stage the overall load strength, if thesimple system uses the limiting pressure type variable displacement pump ora pair of association pumps for the oil, then only must calculate the fast stageand the labor enters the stage the overall load strength.1.2.2 oil motors loadWhen the operating mechanism makes the rotary motion, the oil motormust overcome the outside load is:ifeMMMM+=(1.6)1.2.2.1 operating duties moment of force Me. The operating duty moment offorce is possibly a definite value, also possibly as necessary changes, shouldcarry on the concrete analysis according to the machine working condition.1.2.2.2 friction moments. In order to revolve the part journal place frictionmoment, its formula is:)(MNGFRMf=(1.7)In the formula: G is revolves the part weight (N); F is the rubbing factor,when the start for the factor, after the start for moves the rubbing factor; R isthe journal radius (m).1.2.2.3 moment of inertiaMi. The moment of inertia which in order to revolvethe part acceleration or decelerates when produces, its formula is:)(MNtJMi=(1.8)In the formula: Is the angle acceleration (r/s2);tis the acceleration ordecelerates the time (s); J is revolves the part rotation inertia(2mKg ),GGDJ412=In the formula:2GDIn order to rotate the part the flywheel effect (2MN ).Each kind may look up According to the type (1.6), separately figures out the oil motor in a operatingcycle various stages load size, then may draw up the oil motor the duty cyclechart2 determinations hydraulic system main parameter52.1 hydraulic cylinders design calculations2.1.1 initially decides the hydraulic cylinder working pressureIn the hydraulic cylinder working pressure main basis cycle of motionvarious stages biggest overall load strength determined, in addition below, butalso needs to consider the factor:2.1.1.1 each kind of equipment different characteristic and use situation.2.1.1.2 considerations economies and the weight factor, the pressure electslowly, then part size big, the weight is heavy; The pressure chooses highsomewhat, then part size small, the weight is light, but to the part manufactureprecision, the sealing property requests high.Therefore, the hydraulic cylinder working pressure choice has two ways:One, elects according to the mechanical type; Two, according to cuts the loadto elect.If the table 2.1, the table 2.2 shows.The table 2.1presses the load to choose the execution file the workingpressureLoad/N50005001000010000200002000030000300005000050000Workingpressure/MPa0.811.522.53344556The table 2.2presses the mechanical type to choose the execution file theworking pressureMechanicaltypeEngine bedFarmmachineryProjectmachineryGrinderAggregatemachine-toolDragonGatedigsthe bedBroachingmachineWorkingpressure/MPaa2358810101620322.2 oil motors design calculation2.2.1 computations oil motor displacementUnder oil motor displacement according to the type decided that,)(28. 63minrmPTVmm=(2.1)In the formula: T is the oil motor load moment of force (N m);PmForoil motor import and export pressure difference (n/m3);is the oil motormechanical efficiency, the common gear and the plunger motor takes 0.9 0.95, the leaf blade motor takes 0.8 0.9.2.2.2 computations oil motor needs the current capacity oil motor themaximum current capacity)(3maxmaxsmnVqm=(2.2)In the formula:Vmis the oil motor displacement (m3/r);nmaxis the oilmotor highest rotational speed (r/s).3 hydraulic pressure parts choice3.1 hydraulic pumps determinations with need the power the computation73.1.1.1 determines the hydraulic pump the biggest working pressure. Thehydraulic pressure pumping station must the working pressure determination,mainly acts according to the hydraulic cylinder in the operating cycle variousstages to have most tremendous pressure p1, in addition the oil pump losesSigma Delta p the oil mouth to the cylinderplace always pressurep,namely+=PPPB1(3.1)Ploses, the pipeline including the oil after the flow valve and otherparts local pressures along the regulation loss and so on, before systempipeline design, may act according to the similar system experience toestimate, common pipeline simple throttle valve velocity modulation systemp is (2 5) 105Pa, with the velocity modulation valve and pipelinecomplex systemPis (5 15) 105Pa,Palso may only considerflows after various control valves pressure loss, but ignores the circuitry alongthe regulation loss, various valves rated pressure loses may searches from thehydraulic pressure part handbook or the product sample, Also may refer to thetable 1.3 selectionsThe table 3.1 is commonly used, the low pressure each kind of valve pressureloses (pn)Valvepn(105Pa)Valvepn(105Pa)Valvepn(105Pa)Valvepn(105Pa)Cone-wayvalve0.30.5Cone-wayvalve38Cone-wayvalve1.52Cone-wayvalve1.52Crossvalve1.53Crossvalve23Crossvalve1.53Crossvalve353.1.2 determines the hydraulic pump current capacityqB8Pumps the current capacityqBbasis functional element operating cyclemust the maximum current capacityqmaxand the system divulges thedetermination3.1.2.1 At the same time when more thanhydraulic cylinders movement,the hydraulic pump current capacity must be bigger than the maximumcurrent capacity which at the same time the movement several hydrauliccylinders (or motor) needs, and should consider the system divulging wearsthe volumetric efficiency drop after the hydraulic pump, namely)()(3maxsmqKqB=(3.2)In the formula: K is the system leakage coefficient, generally takes 1.1 1.3, the great current capacity takes the small value, the small current capacitytakes the great value )max(q; For at the same time movement hydrauliccylinder (or motor) is biggest (m3/s).3.1.2.2 chooses the hydraulic pump the specificationTable 3.2 hydraulic pumps overall effectiveness indicesHydraulicpump typeGear pumpThe screwrod pumpsVane pumpRam pumpOveralleffectivenessindex0.60.70.650.800.600.750.800.85Rotational speed and pumps which according to the above power, mayselect the standard electric motor from the product sample, again carries on,causes when the electric motor sends out the maximum work rate,inpermission scope.3.2 valves class parts choice3.2.1 choices bases9The choice basis is: Rated pressure, maximum current capacity,movement way, installment fixed way, pressure loss value, operatingperformance parameter and working life and so on.3.2.2 selector valves class parts should pay attention question3.2.2.1 should select the standard stereotypia product as far as possible,only if does not have already time only then independently designsspecial-purp3.2.2.2 valves class parts specification main basis class after this valve fatliquor most tremendous pressure and maximum current capacity selection.When chooses the overflow valve, should according to the hydraulicpump maximum current capacity selection; When chooses the throttlevalve and the velocity modulation valve, should consider its minimumstable current capacity satisfies the machine low-speed performance therequest3.3 accumulators choices3.3.1 accumulators use in to supplement when the hydraulic pump suppliesthe oil insufficiency, its dischargeable capacity is)(3mtqKLAVBii=(3.3)In the formula: A is the hydraulic cylinder active surface (m2); L is thehydraulic cylinder travelling schedule (m); K is the hydraulic cylinder losscoefficient, when the estimate may take K = 1.2; Supplies the oil currentcapacity for the hydraulic pump (m3/s); T is the operating time (s).3.3.2 accumulators make the emergency energy, its dischargeable capacity is:)(3mtqLAVBii=(3.4)When the accumulator uses in absorbs the pulsation to relax thehydraulic pressure impact, should take it as in the system a link if to beconnected partially together synthesizes considers its dischargeable capaciAccording to the dischargeable capacity which extracts and considered otherrequests, then chooses the accumulator the form103.4 pipelines choices3.4.1 drill tubings types choiceIn the hydraulic system uses the drill tubing divides the hard tube and thehose, the choice drill tubing should have enough passes flows the section andthe bearing pressure ability, simultaneously, should reduce the pipeline as faras possible, avoids the extreme turn and the section sudden change.3.4.1.1 steel pipes: Center the high tension system selects the seamlesssteel pipe, the low pressure system selects the welded steel pipe, the steelpipe price lowly, performance good, the use is widespread3.4.1.2 copper pipes: The copper tube working pressure below 6.5 10MPa,the instable tune, is advantageous for the assembly; Yellow copper pipewithstanding pressure higher, reaches 25MPa, was inferior to the copper tubeis easy to be curving. Copper pipe price high, earthquake resistance abilityweak, is easy to cause the fat liquor oxidation, should as far as possible littleuse, only uses in the hydraulic unit to match meets not the convenient spot.3.4.2 drill tubings sizes determination3.4.2.1 drill tubings inside diameters d presses down the type computationd=(3.5)In the formula: Q is passes the drill tubing the maximum current capacity(m3/s); V speed of flow which permits for the pipeline in (m/s). The commonoil suction pipe takes 0.5 5 (m/s); The pressure oil pipe takes 2.5 5 (m/s);The oil return pipe takes 1.5 2 (m/s).3.4.2 drill tubings sizes determination)(2dp(3.6)In the formula: P is in the tube the biggest working pressure; When n isthe safety coefficient, steel pipe p 7MPa, takes n=8; When p 17.5MPa, takes n=4.11According to drill tubing inside diameter and wall thickness which calculates,looks up the handbook selection standard specification drill tubing3.5 fuel tank designThe fuel tank function is the oil storage, disperses the oil discharge thequantity of heat, in the precipitation oil the impurity, is leisurely in the oil thegas3.5.1 fuel tanks designs main point3.5.1.1 fuel tanks should have the enough volume to satisfy the radiation,simultaneously its volume should guarantee in the system the fat liquorcompletely flows when the fuel tank does not seep out, the fat liquor liquidlevel should not surpass the fuel tank highly 80%.3.5.1.2 suction boxes tubes and the oil return pipe spacing should be as faras possible big3.5.1.3 fuel tanks bases should have the suitable ascent, releases the oil mouthto set to the most low spot, in order to drains the oil3.6 oil filters choicesChooses the oil filter the basis to have following several3.6.1 bearing capacitiesAccording to system pipeline working pressure determination.3.6.2 filters the precision:According to is protected the part the precision request determination3.6.3 flow the ability:According to through maximum current capacity determination.3.6.4 resistance pressure drops:Should the satisfied filter material intensity and the coefficient request.4 hydraulic systems performance12In order to judge the hydraulic system the design quality, needs to lose tothe system pressure, to give off heat , the efficiency and system dynamiccharacteristic and so on4.1 circuitries pressure losesAfter hydraulic pressure part specification model and pipeline sizedetermination, may the more accurate computing system pressure loss, thepressure loss include: The oilloses ,LPthe local pressure after the pipelineCPalong the regulation pressure damagesflows after the valve class partpressure lossVP, namely:VCLPPPP+=( (4.1) )System adjustment pressure:PPP+10(4.2)In the formula: P0For hydraulic pump working pressure or legadjustment pressure; P1In order to execution working pressure.If calculatesPin the primary election system working pressure timethe is sketchier than designation pressure to lose is much bigger than, shouldremove entire related part, auxiliary specification, again definite pipeline size.4.2 systems give off heatThe system gives off heat originates from the system interior energy loss,like the hydraulic pump and the functional element power loss, the overflowvalve overflow loses, the hydraulic valve and the pipeline pressure loss and soon.The system gives off heat the power P computation)(1(WPPB=(4.3)In the formula: PB is the hydraulic pump power input (W); Is thehydraulic pump overall effectiveness indexIf in a operating cycle has several working procedures, then may actaccording to each working procedure the calorific capacity, extracts thesystem unit time the average calorific capacity:13)()1 (11WtPTPinibi=（4.4）In the formula: T is the operating cycle cycle (s); tiFor i workingprocedure operating time (s); piis in the circulation the i working procedurepower input (W).4.3 systems efficiencyThe hydraulic system efficiency is by the hydraulic pump, the functionalelement and the hydraulic pressure return route efficiency determinedThe hydraulic pressurecreturn route efficiency generally may use thetype to calculate:2221.2211bbbbcqpqpqpqp+=(4.5)In the formula: p1，q1；p2，q2； For each functional element workingpressure and current capacity; pB1，qB1；pB2，qB2is each hydraulic pumpsupplies the oil pressure and the current capacity.Hydraulic system overall effectiveness index:cmB+=(4.6)In the formula:BFor hydraulic pump overall effectiveness index;mIn order to functional element overall effectiveness index;cFor returnroute efficiency5 draws up the regular worker mapping and the compilation technologydocumentPasses through after the hydraulic system performance and the essentialrevision, then may draw up the regular worker mapping, it including planhydraulic system schematic diagram, system pipeline assembly drawing andeach kind of non- standard part design drawing.In the official hydraulic system schematic diagram must mark varioushydraulic pressure part the model specification. Regarding automaticityhigher engine bed, but also should include the movement part the cycle ofmotion chart and the electro-magnet, the pressure switch active status.145.1 determinations hydraulic system parameterMay know by the operating mode analysis in, the labor enters the stagethe load strength to be biggest, therefore, the hydraulic cylinder workingpressure according to this load strength computation, according to thehydraulic cylinder and the load relations, p1=40105Pa. This engine bed forthe drill hole aggregate machine-tool, for prevented drills through beforewhen occurs flushes the phenomenon, the hydraulic cylinder oil dischargecavity should have the back pressure, 、p2=6105Pa, for causes quickly toenter quickly draws back the speed to be equal, selects212AA =thedifferential motion cylinder, the hypothesis quickly enters the oil dischargepressure which, quickly draws back to lose forp=7105Pa.5.2 choices hydraulic pressure part5.2.1 chooses the hydraulic pump and the electric motor5.2.1.1 determines the hydraulic pump the working pressure.Front had determined the hydraulic cylinder the biggest workingpressure for 40105Pa, selects the intake pipe road pressure to losep=8105Pa, its adjustment pressure is generally bigger than the systembiggest working pressure 5105Pa, therefore pumps working pressure PB=(40 + 8 + 5) 105 = 53105PaThis is the working pressure which the high-pressured small currentcapacity pumps.The hydraulic cylinder quickly draws back when the working pressurequickly enters when is bigger than, takes its pressure to lose Delta p =4105Pa, then quickly draws back time pumps the working pressure is:PB=(16.44)10520.4105PaThis is the working pressure which the low pressure great currentcapacity pumps.5.2.1.2 hydraulic pumps current capacities. Quickly enters when the currentcapacity is biggest, its value is 30L/min, the quantity enters when the labor,its value is 0.51L/min, takes K = 1.2,15Then:q