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HYDRAULICS

253

LS razvodni ventili 207, NO. 20LS directional control valves 207, ND. 20

KLIPNI, HIDRAULI^KI I RU^NO AKTIVIRANISPOOL TYPE, HYDRAULICALLY AND HAND ACTUATION

LS - Load Sensing system with accurate flow control in accordiance with sysem requirements (flow on demant control) is imperative for optimising the energy balance of a hydraulic circuit Aplication to building - construction machines, cranes and fork lift trucksWhen here is no requirements for flow supply to the actuators, the LS system automatically adjusts the pump to minimum delivery When flow is require by one or several actuators, the LS system determines the curent total requrement exactly. The displacement of the pump is then automatically adjusted accordingly The Load Sensing signal in the LS sistem constant adjusts pump pressure to the current level required by the highest loaded actuator The power loss for the pump withthe load sensing is derived from the product of the current pump delivery rate and the control pressure of approx. 20 bar necessary for the system Mounting in sandwich system possibleThis remarqable fatique - reducing control system is this based on the pressure compesators located down stream of the valve control lands. Through a system of mutual depedence. These ensuere that the fluid flow rates to the individual actuators remain in a constant relation ship to one another in the maximum pump delivery capacity is no longer sufficient to cover the pover demand resulting from the simultaneous actuation of several machine fuctions Block diagram showing the LS sinchronous control system for two actuators. Upstream of the measuring oficies, the pump pressure is p1. Downstream of the measuring orifices it is the currently highest actuator pressure p2 which prevails. Gives identical p differential pressure valves at all two orifices, the two flow rates will bein accordiance with the appurteant oriffice crros section Note: this LS - values can be combined with our Load Sensing control pump - APR type

1. Ku}i{te2. Sekundarni ventil pritsika3. Glavni klip4. Element za centriranje5. Vent. za ograni~. pritiska6. Naizmeni~ni ventil7. Prigu{no mesto8. Element za aktiviranje

1. Housing2. Secondary pressure valve3. Main spool4. Centred element5. Pressure relief valve6. Shuttle valve7. Throttle location8. Actuation element

D

D

6 7 5 3 8

4

LS - Load Sensing sistem sa regulacijom protoka shodno potrebi pru`a optimum u energetskom bilansu hidrauli~kog sistema Primena na gra|evinskim ma{inama, dizalicama i vilju{karimaKada nema potrebe za protokom ka potro{a~ima, LS -sistem automatski pode{ava pumpu na minimalni protokAko jedan ili vi{e potro{a~a zahtevaju protok, LS - sistem ovu potrebu ta~no sabira i automatski reguli{e radnu zapreminu pumpeLoad Sensing signal reguli{e pritisak pumpe shodno potrebi najoptere}enijeg potro{a~aGubitak snage kod pumpi sa LS regulatorom proizilazi iz proizvoda trenutnog protoka pumpe i neophodnog komandnog pritiska od 20 barMogu}e je komponovanje razvodnih elemenata u sandwich sistemuPrincip ovog u praksi dokazanog, konfornog upravlja~kog sistema, zasniva se na pritisnoj vagi u razvodnom ventilu. Razvodni ventil obezbe|uje da pojedini potro{a~i dobijaju protoke, koji ostaju u stalnom odnosu i kad je maksimalni protok pumpe nedovoljan da pokrije zadate funkcije ma{ine[ema prikazuje LS upravlja~ki sistem za dva potro{a~a. Ispred mernih blendi deluje pritisak pumpe p1. Iza blendi deluje momentalno najve}i pritisak p2 nekog potro{a~a. Kod jednakih razlika pritisaka p na obe merne blende dobijaju se dva protoka koji uvek odgovaraju proto~nom preseku merne blendeNapomena: LS razvodni ventili mogu se kombinovati sa pumpama promenljivog protoka tipa APR

Proporcionalni ventili Proportional valves

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254

OP[TEGENERAL

TEHNI^KE KARAKTERISTIKE

TECHNICAL DATA

HIDRAULI^KEHYDRAULIC

11,6 - 230

-20 ... +70

Broj razvodnih sekcijaNo of distribution sections

SimbolSymbol

Radna te~nostWorking fluid

mineralno uljemineral oil

viskozitetviscosity

temperaturatemperature

o( C)

2(mm /s)

30

ProizvoljanOptional

...+50

PritisakPressure

Polo`aj ugradnjeMounting positionTemperatura okolineAmbient temperature

o( C)

1...6

(bar)

Nazivni otvorNominal size

Videti ozna~avanjeSee designation

NA^IN AKTIVIRANJAACTUATION METHOD

hod klipa piston stroke

20

ProtokFlow

(l/min)160250

420

(mm)Ru~no - Hand -

Ru~no - sila oprugeHand - spring force

13

(N)

Hidraili~ko -Hydraulic -

hod klipa piston stroke

(mm)

Vod / Line PVod / Line CVod / Line PVod / Line C

Vod / Line LSVod / Line RVod / Line a

350

420

8 - 25 (max 30)

for pos. 0 = 16; for pos. 1,2 = 290

13

2KARAKTERISTI^NI DIJAGRAMI (ulje viskoziteta 40mm /s)2CHARACTERISTIC DIAGRAMS (oil viscosity 40mm /s)

ProtokFlow (l/min)

Pad

pri

tisk

aP

ress

ure

dro

p(b

ar)

Upravlja~ki pritisakPilot pressure

Pad pritiskaPressure drop(bar)

ProtokFlow (l/min)

Pro

tok

Flo

w(l

/min

)

(bar)

Pro

tok

Flo

w(l

/min

)P

ritis

k p

od

e{a

van

jaP

ress

ure

sett

ing

ran

ge

a(b

ar)

Pritisna vagaTwo - way pressure compesator

Primarni vent. za ograni~enje pritiskaPrimary pressure relief valve

3

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OZNA^AVANJE I SIMBOLI

DESIGNATION AND SYMBOLS

207 - 36600207 - 32600207 - 31300207 - 31500207 - 31600

207 - 31500 - 1

207 - 34600 H

207 - 31600 - 1

207 - 31600 - 2

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256

UGRADNI CRTE@ (mere u mm)

MOUNTING DRAWING (dimensions in mm)

207 - 31300207 - 31500207 - 31600207 - 31500 - 1

207 - 31600 - 2

207 - 31600 - 1

5

257

H

UGRADNI CRTE@ (mere u mm)

MOUNTING DRAWING (dimensions in mm)

207 - 32600

207 - 36600

6

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258

UGRADNI CRTE@ (mere u mm)

MOUNTING DRAWING (dimensions in mm)

207 - 34600 H