Trouble Diagnosis and Elimination of Pipe Jacking Machine

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Time of issue:2020-09-29 16:30
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(Summary description)1.Noactionofthecorrectionsystem AΦ1800mmmuddywaterpressurizedpipejackingmachine(canbeexpandedto2000mm),thetotallengthoftherotaryexcavatorsystemis4705mm,thecutterheadtorqueis354kN·m,thecutterheadspeedis2.3r/min,andthedrivingpoweris30×3kW.Thestrokeofthecorrectionhydrauliccylinderis85mm,andthethrustofthecorrectionhydrauliccylinderis980kN×thetotalmassofthemainengine(t).Whenthepipejackingmachinewas200mawayfromthepipe,thecorrectionsystemfailedandthecorrectionactioncouldnotbegenerated,makingtheconstructionimpossible. Thecorrectionsystemoftherotaryexcavationsystemofthepipejackingmachineadoptsanelectro-hydraulicintegratedoperatingsystem,whichconsistsofahydraulicoiltank,anoilfilter,anoilfilterscreen,anelectricmotor,ahydraulicpump,aone-wayvalve,anoverflowvalve,apressuregauge,andasolenoidComposedofreversingvalve,hydrauliclock,overloadreliefvalve,mudwatertankelectromagneticreversingvalve,mudwatertankdoorreliefvalve,correctionhydrauliccylinderandothercomponents. Thehydraulicpumptransmitsthehydraulicoiltothecontrolvalve,andtransmitsittothecorrectionhydrauliccylinderaccordingtotherequiredcorrectionconditions.However,becausetheworkingpressureofthecorrectionhydrauliccylindercannotreachtherequired20MPa(only16MPa),thesystempressureislow.Thecorrectinghydrauliccylindercannotperformnormalcorrectingoperations. Thereasonsforthelowpressureofthecorrectionhydraulicsystemareasfollows:theoverflowvalvefails;theelectromagneticreversingvalveisseverelywornandcausesinternalleakage;thecorrectionhydrauliccylinderisleaked;theoilinletfilterisblocked;thepowerofthehydraulicpumpisreduced. Accordingtotheanalysisresults,adjustingthepressureoftheoverflowvalvehasnoobviouseffect;usingthetranspositionmethodtoreplacetheoverflowvalveofthesametypeinotherpartsfordebugginghasnoeffect,indicatingthattheoverflowvalveisgood.Checktheelectromagneticreversingvalve.Nooilleakage,loosevalvecoreanduncleargearsarefound,indicatingthattheelectromagneticreversingvalveisalsogood.Thepressuretestofthecorrectionhydrauliccylinderwascarriedout,thepressurewasnormal,andnointernalleakagewasfound.Theoilinletfilterwasremovedforinspection,andnoblockagewasfound.Finally,itisjudgedthatthepowerdropofthehydraulicpumpisthemaincauseofthefailure. Stopthecorrectionhydraulicsystem,cutoffthepowersupply,removethehydraulicpumpfromtheoiltank,replacethehydraulicpumpofthesamemodel,andrunthetestmachine.Thesystempressurecanreach26MPa,andthecorrectionworkisworkingnormally. 2.Thecorrectionsystemcannotcorrecttotheleft AΦ2000mmearthpressurebalancepipejackingmachine,afteroverhaulingtheelectricaloperation,hydraulicpressureandsoildumpingsystems,duringtheomni-directionaladjustmentandtestmachineprocess,itwasfoundthatthecorrectionsystemoftherotaryexcavationsystemdidnotmovetotheleft,andtheotherdirectionswerenormal. First,usethetranspositionmethodtotranspositiontheelectromagneticdirectionalvalveontheleftandright,buttheresultisthattheleftsidecannotbecorrected.Thentheleftandrighthydrauliccylindersaretransposedanddebugged,andtheleftsidestillcannotbecorrected.Throughtheabovetranspositiondebugging,itshowsthatthehydrauliccircuitofthecorrectionsystemisgood.Whencontinuingtheinvestigation,thefrontswingpartandtherearfollowerpartoftherotaryexcavationsystemweredisassembledandseparated,anditwasfoundthatthepipelinewaterproofrubberringatthejunctionofthefrontsteelshellandtherearsteelshellwasaginganddeformed,whichaffectedtheleftwardmovementofthecorrectionsystem. Theaginganddeformedpipewaterproofrubberringatthejunctionofthefrontsteelshellandtherearsteelshellwasreplaced.Afterthetestmachine,thecorrectionsystemmovedtotheleftnormally. 3.Failureofthereversingvalveofthehydraulicpumpstation Intheconstructionofsewagepipelines,afterthehydraulicpumpstationofthepipejackingmachineworkedcontinuouslyfor1h,thereversingvalvecouldnotbechangedsmoothlyasrequired,sometimesgoodandsometimesbad. Thehydrauliccircuitofthishydraulicpumpstationisrelativelysimple.Itusesthe4WE16G/EW220solenoiddirectionalvalve.After1hofoperation,thesolenoidvalveheatsupandcannotchangedirectionnormally. Removethesolenoiddirectionalvalve,surveyandmapthesolenoiddirectionalvalvebase,andfindamanualdirectionalvalvemodel4WMM16G50accordingtothesizeofthebase,anditworksnormallyafterinstallation. 4.Mudentersintothereducerboxofthespiralsoilconveyor AΦ3000mmearthpressurebalancepipejackingmachineundertakestheconstructiontaskofjackingΦ3000mmsteelpipeswithatotallengthof1km.Whentherotaryexcavationsystemwasdiggingto800m,itwasfoundthattherewasmudinthereducerboxofthespiralsoilconveyor. Therearetworeasonsforthisfailure:oneisthatthesealingringofthescrewshaftjournalisseverelywornandthejournalisnotwellsealed,whichcausessoiltoenterthereducerboxfromthescrewshaftjournal;theotheristhattheearthpressureofthespiralsoilconveyorisgreaterthanThepressureinthereducerboxcausessoiltoenterthereducerbox.However,thesealingringofthescrewshaftjournalisanewpartthatisreplacedbeforeconstructionandwillnotwearsoquickly.Therefore,theearthpressureisgreaterthanthepressureinthereducerboxasthemainreasonforthefailure.Itisunderstoodt

Trouble Diagnosis and Elimination of Pipe Jacking Machine

(Summary description)1.Noactionofthecorrectionsystem AΦ1800mmmuddywaterpressurizedpipejackingmachine(canbeexpandedto2000mm),thetotallengthoftherotaryexcavatorsystemis4705mm,thecutterheadtorqueis354kN·m,thecutterheadspeedis2.3r/min,andthedrivingpoweris30×3kW.Thestrokeofthecorrectionhydrauliccylinderis85mm,andthethrustofthecorrectionhydrauliccylinderis980kN×thetotalmassofthemainengine(t).Whenthepipejackingmachinewas200mawayfromthepipe,thecorrectionsystemfailedandthecorrectionactioncouldnotbegenerated,makingtheconstructionimpossible. Thecorrectionsystemoftherotaryexcavationsystemofthepipejackingmachineadoptsanelectro-hydraulicintegratedoperatingsystem,whichconsistsofahydraulicoiltank,anoilfilter,anoilfilterscreen,anelectricmotor,ahydraulicpump,aone-wayvalve,anoverflowvalve,apressuregauge,andasolenoidComposedofreversingvalve,hydrauliclock,overloadreliefvalve,mudwatertankelectromagneticreversingvalve,mudwatertankdoorreliefvalve,correctionhydrauliccylinderandothercomponents. Thehydraulicpumptransmitsthehydraulicoiltothecontrolvalve,andtransmitsittothecorrectionhydrauliccylinderaccordingtotherequiredcorrectionconditions.However,becausetheworkingpressureofthecorrectionhydrauliccylindercannotreachtherequired20MPa(only16MPa),thesystempressureislow.Thecorrectinghydrauliccylindercannotperformnormalcorrectingoperations. Thereasonsforthelowpressureofthecorrectionhydraulicsystemareasfollows:theoverflowvalvefails;theelectromagneticreversingvalveisseverelywornandcausesinternalleakage;thecorrectionhydrauliccylinderisleaked;theoilinletfilterisblocked;thepowerofthehydraulicpumpisreduced. Accordingtotheanalysisresults,adjustingthepressureoftheoverflowvalvehasnoobviouseffect;usingthetranspositionmethodtoreplacetheoverflowvalveofthesametypeinotherpartsfordebugginghasnoeffect,indicatingthattheoverflowvalveisgood.Checktheelectromagneticreversingvalve.Nooilleakage,loosevalvecoreanduncleargearsarefound,indicatingthattheelectromagneticreversingvalveisalsogood.Thepressuretestofthecorrectionhydrauliccylinderwascarriedout,thepressurewasnormal,andnointernalleakagewasfound.Theoilinletfilterwasremovedforinspection,andnoblockagewasfound.Finally,itisjudgedthatthepowerdropofthehydraulicpumpisthemaincauseofthefailure. Stopthecorrectionhydraulicsystem,cutoffthepowersupply,removethehydraulicpumpfromtheoiltank,replacethehydraulicpumpofthesamemodel,andrunthetestmachine.Thesystempressurecanreach26MPa,andthecorrectionworkisworkingnormally. 2.Thecorrectionsystemcannotcorrecttotheleft AΦ2000mmearthpressurebalancepipejackingmachine,afteroverhaulingtheelectricaloperation,hydraulicpressureandsoildumpingsystems,duringtheomni-directionaladjustmentandtestmachineprocess,itwasfoundthatthecorrectionsystemoftherotaryexcavationsystemdidnotmovetotheleft,andtheotherdirectionswerenormal. First,usethetranspositionmethodtotranspositiontheelectromagneticdirectionalvalveontheleftandright,buttheresultisthattheleftsidecannotbecorrected.Thentheleftandrighthydrauliccylindersaretransposedanddebugged,andtheleftsidestillcannotbecorrected.Throughtheabovetranspositiondebugging,itshowsthatthehydrauliccircuitofthecorrectionsystemisgood.Whencontinuingtheinvestigation,thefrontswingpartandtherearfollowerpartoftherotaryexcavationsystemweredisassembledandseparated,anditwasfoundthatthepipelinewaterproofrubberringatthejunctionofthefrontsteelshellandtherearsteelshellwasaginganddeformed,whichaffectedtheleftwardmovementofthecorrectionsystem. Theaginganddeformedpipewaterproofrubberringatthejunctionofthefrontsteelshellandtherearsteelshellwasreplaced.Afterthetestmachine,thecorrectionsystemmovedtotheleftnormally. 3.Failureofthereversingvalveofthehydraulicpumpstation Intheconstructionofsewagepipelines,afterthehydraulicpumpstationofthepipejackingmachineworkedcontinuouslyfor1h,thereversingvalvecouldnotbechangedsmoothlyasrequired,sometimesgoodandsometimesbad. Thehydrauliccircuitofthishydraulicpumpstationisrelativelysimple.Itusesthe4WE16G/EW220solenoiddirectionalvalve.After1hofoperation,thesolenoidvalveheatsupandcannotchangedirectionnormally. Removethesolenoiddirectionalvalve,surveyandmapthesolenoiddirectionalvalvebase,andfindamanualdirectionalvalvemodel4WMM16G50accordingtothesizeofthebase,anditworksnormallyafterinstallation. 4.Mudentersintothereducerboxofthespiralsoilconveyor AΦ3000mmearthpressurebalancepipejackingmachineundertakestheconstructiontaskofjackingΦ3000mmsteelpipeswithatotallengthof1km.Whentherotaryexcavationsystemwasdiggingto800m,itwasfoundthattherewasmudinthereducerboxofthespiralsoilconveyor. Therearetworeasonsforthisfailure:oneisthatthesealingringofthescrewshaftjournalisseverelywornandthejournalisnotwellsealed,whichcausessoiltoenterthereducerboxfromthescrewshaftjournal;theotheristhattheearthpressureofthespiralsoilconveyorisgreaterthanThepressureinthereducerboxcausessoiltoenterthereducerbox.However,thesealingringofthescrewshaftjournalisanewpartthatisreplacedbeforeconstructionandwillnotwearsoquickly.Therefore,theearthpressureisgreaterthanthepressureinthereducerboxasthemainreasonforthefailure.Itisunderstoodt

Categories:Technical Services
Author:
Origin:
Time of issue:2020-09-29 16:30
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1. No action of the correction system

A Φ1 800 mm muddy water pressurized pipe jacking machine (can be expanded to 2000mm), the total length of the rotary excavator system is 4705 mm, the cutter head torque is 354 kN·m, the cutter head speed is 2.3r/min, and the driving power is 30× 3 kW. The stroke of the correction hydraulic cylinder is 85 mm, and the thrust of the correction hydraulic cylinder is 980 kN×the total mass of the main engine (t). When the pipe jacking machine was 200 m away from the pipe, the correction system failed and the correction action could not be generated, making the construction impossible.

The correction system of the rotary excavation system of the pipe jacking machine adopts an electro-hydraulic integrated operating system, which consists of a hydraulic oil tank, an oil filter, an oil filter screen, an electric motor, a hydraulic pump, a one-way valve, an overflow valve, a pressure gauge, and a solenoid Composed of reversing valve, hydraulic lock, overload relief valve, mud water tank electromagnetic reversing valve, mud water tank door relief valve, correction hydraulic cylinder and other components.

The hydraulic pump transmits the hydraulic oil to the control valve, and transmits it to the correction hydraulic cylinder according to the required correction conditions. However, because the working pressure of the correction hydraulic cylinder cannot reach the required 20 MPa (only 16 MPa), the system pressure is low. The correcting hydraulic cylinder cannot perform normal correcting operations.

The reasons for the low pressure of the correction hydraulic system are as follows: the overflow valve fails; the electromagnetic reversing valve is severely worn and causes internal leakage; the correction hydraulic cylinder is leaked; the oil inlet filter is blocked; the power of the hydraulic pump is reduced.

According to the analysis results, adjusting the pressure of the overflow valve has no obvious effect; using the transposition method to replace the overflow valve of the same type in other parts for debugging has no effect, indicating that the overflow valve is good. Check the electromagnetic reversing valve. No oil leakage, loose valve core and unclear gears are found, indicating that the electromagnetic reversing valve is also good. The pressure test of the correction hydraulic cylinder was carried out, the pressure was normal, and no internal leakage was found. The oil inlet filter was removed for inspection, and no blockage was found. Finally, it is judged that the power drop of the hydraulic pump is the main cause of the failure.

Stop the correction hydraulic system, cut off the power supply, remove the hydraulic pump from the oil tank, replace the hydraulic pump of the same model, and run the test machine. The system pressure can reach 26 MPa, and the correction work is working normally.

2. The correction system cannot correct to the left

A Φ2000mm earth pressure balance pipe jacking machine, after overhauling the electrical operation, hydraulic pressure and soil dumping systems, during the omni-directional adjustment and test machine process, it was found that the correction system of the rotary excavation system did not move to the left, and the other directions were normal.

First, use the transposition method to transposition the electromagnetic directional valve on the left and right, but the result is that the left side cannot be corrected. Then the left and right hydraulic cylinders are transposed and debugged, and the left side still cannot be corrected. Through the above transposition debugging, it shows that the hydraulic circuit of the correction system is good. When continuing the investigation, the front swing part and the rear follower part of the rotary excavation system were disassembled and separated, and it was found that the pipeline waterproof rubber ring at the junction of the front steel shell and the rear steel shell was aging and deformed, which affected the leftward movement of the correction system.

The aging and deformed pipe waterproof rubber ring at the junction of the front steel shell and the rear steel shell was replaced. After the test machine, the correction system moved to the left normally.

3. Failure of the reversing valve of the hydraulic pump station

In the construction of sewage pipelines, after the hydraulic pump station of the pipe jacking machine worked continuously for 1 h, the reversing valve could not be changed smoothly as required, sometimes good and sometimes bad.

The hydraulic circuit of this hydraulic pump station is relatively simple. It uses the 4WE16G/EW220 solenoid directional valve. After 1 h of operation, the solenoid valve heats up and cannot change direction normally.

Remove the solenoid directional valve, survey and map the solenoid directional valve base, and find a manual directional valve model 4WMM16G50 according to the size of the base, and it works normally after installation.

4. Mud enters into the reducer box of the spiral soil conveyor

A Φ3 000 mm earth pressure balance pipe jacking machine undertakes the construction task of jacking Φ3 000 mm steel pipes with a total length of 1 km. When the rotary excavation system was digging to 800 m, it was found that there was mud in the reducer box of the spiral soil conveyor.

There are two reasons for this failure: one is that the sealing ring of the screw shaft journal is severely worn and the journal is not well sealed, which causes soil to enter the reducer box from the screw shaft journal; the other is that the earth pressure of the spiral soil conveyor is greater than The pressure in the reducer box causes soil to enter the reducer box. However, the sealing ring of the screw shaft journal is a new part that is replaced before construction and will not wear so quickly. Therefore, the earth pressure is greater than the pressure in the reducer box as the main reason for the failure. It is understood that the operator did not open the dirt tank gate when the machine was turned on and digging, so the pressure of the dirt tank was too high, which eventually caused the dirt to enter the reducer box.

The troubleshooting is divided into 2 steps. The first step: remove the oil drain plug of the reducer, start the screw soil conveyor motor, and drain the soil in the reducer box from the oil drain. After discharging a part of the soil, add the hyperbolic gear oil from the oil filling port, and then start the screw soil conveyor motor to fully mix the soil in the reducer case with the gear oil, and then discharge it from the oil drain. Work in this cycle until the soil in the reducer box is exhausted. Step 2: After the soil in the reducer box is exhausted, add diesel oil into the reducer box to clean the reducer gears. After cleaning, add the hyperbolic gear oil according to the standard amount.

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Trouble Diagnosis and Elimination of Pipe Jacking Machine

Trouble Diagnosis and Elimination of Pipe Jacking Machine