Synchronisation circuits for two cylinders.
Synchronisation o
Synchronisation of two cylinders is possible by usif two cylinders is possible by using flow contng flow control valve and tedium pump asrol valve and tedium pump as discussed ear
discussed earlierlier. Few special circuits are also po. Few special circuits are also possiblssible to e to achieve synchronisation; some of themachieve synchronisation; some of them are as follows.
are as follows.
Diamond circuit:
-Diamond circuit: - In this circui In this circuit tt two flow controwo flow control vall valves are used tves are used to coo control speed ntrol speed of two cylinof two cylindersders in both directions. But forward and reverse speed
in both directions. But forward and reverse speed could not be could not be adjusted and selected separatelyadjusted and selected separately..
Also during up
Also during up strostroke the contrke the control is ol is meter-in and during down stroke, it is mmeter-in and during down stroke, it is meter-oeter-out.ut.
To increase accuracy, one fl
To increase accuracy, one flow coow control valve could be replaced with ntrol valve could be replaced with proproportportional electro-hydraulicional electro-hydraulic flow contro
flow control valvl valve. This valve senses the variation ae. This valve senses the variation and adjusts tnd adjusts the flhe flow tow to aco achieve hihieve high accuracgh accuracyy..
Doamond Circuit Doamond Circuit
Figure No 10.21.3 Figure No 10.21.3
Synchronisation Circuit Synchronisation Circuit Study of Hydraulic Circuit
Study of Hydraulic Circuit
“Design and
“Design and Manufacturing of HydrManufacturing of Hydrauliauli c Pressc Presses.” es.” ©: Q.S. Kh©: Q.S. Khanan 10-5810-58
Pully
Pully Steel plateSteel plate
M o v e a b l e e l e m e n t
M o v e a b l e e l e m e n t Sensor of servoSensor of servo Valve
Valve
S e r v o V a l v e F o r S e r v o V a l v e F o r Synchronisation Synchronisation
P P M
M
Synchronisation by serro -valve Synchronisation by serro -valve
Figure No 10.21.4 Figure No 10.21.4
Synchronisation Circuit Synchronisation Circuit Study of Hydraulic Circuit
Study of Hydraulic Circuit
10.22 Circuit Diagram of Drill 10.22 Circuit Diagram of Drill
Pump Pump:- :-A variabl
A variable discharge pump is used so e discharge pump is used so that that as load increases, speed as load increases, speed decreases and when drdecreases and when drilills getls get j
jammammed ed due due to to any any reason reason it it stops stops rotatirotating. ng. ReduceReduced d or or no no didischascharge rge from from varivariablable e didisplsplacemacementent pum
pump p at at hihigh gh prespressure sure safsafe e guard guard agaiagainsnst t oil oil heaheatinting.g.
Direction control valve Direction control valve:- :-Advantage of using three p
Advantage of using three positions all port block valves is that at ositions all port block valves is that at neutral position cylineutral position cylinder remainsnder remains locked, and it does not
locked, and it does not drain-out system pressure.drain-out system pressure.
Flow control valve Flow control valve: : --By usin
By using flow controg flow control vall valve we controve we control spindll spindle approe approach and returach and return speed.n speed.
Four
Four-way-two po-way-two position direction contsition direction control valverol valve:-
:-Because of two positions, cylinder will either clamp or un-clamp. Circuit is designed in such a way Because of two positions, cylinder will either clamp or un-clamp. Circuit is designed in such a way that whe
that when solenoid valve n solenoid valve un-energun-energised it remaiised it remains in clns in clamp position. These saamp position. These safeguards acfeguards accidentalcidental released of job.
released of job.
Check valves
Check valves safeguards variable dis safeguards variable displacemplacement puent pump against sudden over mp against sudden over loadinloading and g and accessesaccesses pres
pressure sure genegenerated rated in in cycylilindenders.rs.
J-type direction cont
J-type direction control valrol valveve is used for drill is used for drill head feed cylinder, so that prhead feed cylinder, so that pressure shouessure should notld not be
be locked locked in in pipe pipe liline ne of of cylcylinderinder. L. Locked pressure ocked pressure may may actuate the actuate the pilpilot operated ot operated check check valvalveve which holds spindle in l
which holds spindle in lifted condifted condition.ition.
Counter balance valve
Counter balance valve develops a back pre develops a back pressure, because ossure, because of whif which drill ch drill head does nohead does not over t over travel due to
travel due to weight of spindleweight of spindle. Because . Because of counter of counter balbalance valvance valve, flow controe, flow control valvl valve also wore also worksks accurately.
accurately.
Pilot operated check valve Pilot operated check valve
locks
locks drill drill head feedhead feeding cyliing cylinder nder in position, so t
in position, so that when drhat when drillillinging stops,
stops, spindle spindle remain stationeryremain stationery and do not slides down due to and do not slides down due to own weight.
own weight.
Reducing valve
Reducing valve is used to is used to reduce pressure supplied to reduce pressure supplied to up-down cylinder wi
down cylinder withouthout reducingt reducing system pressure.
system pressure.
Meter-out type flow con Meter-out type flow controltrol valve
valve is used to control is used to control spin
spindle speed.Meter-out dle speed.Meter-out typetype valve reduces fluctuation in valve reduces fluctuation in speed much better than speed much better than meter-in type circuit,with change meter-in in type circuit,with change in cutting load.
Drill Head feed Cylinder Drill Head feed Cylinder
5
Circuit Diagram of Drill Circuit Diagram of Drill Study of Hydraulic Circuit
Study of Hydraulic Circuit
“Design and
Honing is simililar to ar to internal grindininternal grinding, but g, but in this process insteain this process instead of grinding wheel grinding stoned of grinding wheel grinding stone sticks are used a
sticks are used and grindinnd grinding stg stone sticks are one sticks are rotatrotated as well as reciprocated ed as well as reciprocated insiinside an cylide an cylindricalndrical object to
object to remove material of object as per requirement. In remove material of object as per requirement. In honing, ovalihoning, ovality as well as taper ty as well as taper of insiof insidede diam
diameter is correcteter is corrected. As per the size and grade ed. As per the size and grade of honinof honing stog stone stick used for ne stick used for honinhoning we getg we get surface fini
surface finish better tsh better than grinding process. han grinding process. Honing procHoning process is generally used iess is generally used in manufacturing of n manufacturing of hydraulic cyli
hydraulic cylinder or cylinder of autnder or cylinder of automoomobilbile engine.e engine.
High flow high pressure pump
High flow high pressure pump:- To reciprocate :- To reciprocate honing head at required honing head at required high speed high flhigh speed high flowow pum
pump p is is used used as as per per requirequiremerement.nt.
Relief valve
Relief valve regulates pressure of reciprocating cylinder. regulates pressure of reciprocating cylinder.
Flow control valve
Flow control valvecontrcontrols the speed of reciprocatols the speed of reciprocat ing cying cylinlinder.der.
Direction control valve
Direction control valve contr controls the direction of reciprools the direction of reciprocating cylicating cylinder.nder.
This
Thissimple counter balance valvesimple counter balance valve offers some back pressur offers some back pressure when cyle when cylinder descends doinder descends down,wn,
bec
because ause of of thithis s speespeed d of of cycylilinder nder remremaiains ns undeunder r control control as as per per fflow low contrcontrol ol valvalve ve settisetting.ng.
Reciprocating cylinder
Reciprocating cylinder: - In honing machin: - In honing machine up ae up and down speed nd down speed of honing head should beof honing head should be same, hence either cylinder in mode double ended. Or differential cylinder is used along with same, hence either cylinder in mode double ended. Or differential cylinder is used along with regenerat
regenerative ciive circuit.rcuit.
Pump
Pump with low discharge is used for hydraulic motor o with low discharge is used for hydraulic motor o f honing head, as revolving speed of f honing head, as revolving speed of honing head is betwe
honing head is between 10-7en 10-70 rpm only0 rpm only, and c, and clampilamping cylinder ing cylinder is opes operatrated only at the beed only at the beginniginningng and at the of
and at the of operationoperation..Relief valveRelief valve contro controls ls working pressure of pump No. 7working pressure of pump No. 7
10-60 Study of Hydraulic Circuit
Study of Hydraulic Circuit
Direction control valve
Direction control valve and and 1212 are used in series b are used in series because of two ecause of two reasons.reasons.
a) Flo
a) Flow is small hence heatw is small hence heating wiling will be miniml be minimum.um.
b)
b) ClClamampiping ng cycylilindernders s are are rarerarely ly used, used, henhence ce it it does does not not ininterfterfere ere fufuncnctiontionining g of of hyhydrauldrauliic c motormotor..
If we use all port block valv
If we use all port block valve in such situation, then one more e in such situation, then one more valvvalve we have to e we have to add to add to unload pumpunload pump when both hydraulic motor and
when both hydraulic motor and clampiclamping cyling cylinder are nder are not not in use. Hence by using two directin use. Hence by using two directionion cont
control valve irol valve in series we save one van series we save one valve.lve.
Flow control valve
Flow control valve, cont, controls and varies the speed of hydraulrols and varies the speed of hydraulic mic motootor attacr attached to honing head.hed to honing head.
Hydraulic Motor
Hydraulic Motor1111:- rot:- rotates the honing head. By usinates the honing head. By using hydraulic g hydraulic motomotor in r in place of place of generalgeneral geared electric m
geared electric motootor, we have full r, we have full and easy control over speed and easy control over speed and torqand torque of honinue of honing head.g head.
Pilot operated check valve
Pilot operated check valve1313 locks t locks the clampihe clamping cyling cylinder under nder under pressure.pressure.Clamping cylinderClamping cylinder1414 holds the job firmly
holds the job firmly, as in honing job is subjected to , as in honing job is subjected to rotrotary toary torque as werque as well ll as up aas up and down pund down pullillingng and pushing force.
and pushing force.
In this hydrauli
In this hydraulic circuit we have used meter c circuit we have used meter in type flin type flow cow controontrol vall valve. Bleed ove. Bleed of type if type is also uses also used.d.
In bleed-off power loss
In bleed-off power loss is comparatively less.is comparatively less.
Honning Honning Study of Hydraulic Circuit
Study of Hydraulic Circuit
“Design and
“Design and Manufacturing of HydrManufacturing of Hydrauliauli c Pressc Presses.” es.” ©: Q.S. Kh©: Q.S. Khanan
clamp cyl
clamp cyl.. Table slide cyl.Table slide cyl.
Lubrication Lubrication
Lub.Return Lub.Return
Ø 100 x Ø 75 x 5000mt Ø 100 x Ø 75 x 5000mt
20 kg/cm 20 kg/cm
7/min 7/min
7.5kw 7.5kw 500 500
95/min 95/min
20kg/cm
20kg/cm 0.5 2kg/cm0.5 2kg/cm
M M