Variable Displacement Pump A4VG - Group VH A/S

8/52 Bosch Rexroth AG | Mobile Hydraulics A4VG | RE 92 003/05.03High Pressure Relief ValveSetting diagramp max≥ 30 baroperating pressure pA, Bat ports A, Bsafety margin∆p drive designpressurepSpboost press.q v1set valuepressure cut-offp Spq v maxdifferential pressure ∆pHDhigh press. (HD) valve settingSetting rangeHigh pressure relief valve, Differential pressurepilot controlled (sizes 71...250) setting ∆p HDSetting range valve 1420 bar∆p 100 - 420 bar 400 bar 1 )(see ordering code)360 bar340 bar320 bar300 bar270 bar250 bar230 bar200 bar150 bar100 bar1 ) Standard valve setting of differential pressure, if not specified.Note: valve setting is done atn = 1000 rpm und V g max (q V 1V 1 )Example: boost pressure 30 bar; operating pressure 400 baroperating pres. p A,B – boost pres. p Sp + safety margin =differential pres. ∆p HD400 bar – 30 bar + 30 bar = 400 barHigh pressure relief valve, Differential pressuredirect controlled (sizes 28...56) setting ∆p HDSetting range valve 3, 5 420 bar∆p 270 - 420 bar 400 bar 1 )(see ordering code)360 bar340 bar320 bar300 bar270 barSetting range valve 4, 6 250 bar∆p 100 - 250 bar 230 bar 1 )(see ordering code)200 bar150 bar100 barBypass functionSizes 28...56: HD valves direct controlled (3), (4): without bypassSizes 28...56: HD valves direct controlled (5), (6): with bypassSizes 71...250:HD valves pilot controlled (1): with bypassSimplification:The bypass function is not shown in the circuitdiagramsThe pilot controlled HD-valves (sizes 71..250)are not shown in the circuit diagrams.Pressure Cut-Off, DThe pressure cut-off corresponds to a pressure regulation which, afterreaching the set pressure, adjusts the pump volume of the pump toV g 0 = 0.This valve prevents the operation of the high pressure relief valveswhen accelerating or decelerating.Both the pressure peaks occurring when the swashplate is swivelledrapidly and also the maximum pressure in the system are safeguardedby the high pressure relief valves.The setting range of the pressure cut-off may be anywhere within theentire working pressure range. However, it must be set 30 bar lowerthan the setting of the high pressure safety relief valves (see settingdiagram).Please state the setting value of the pressure cut-off in clear text whenordering.Please state in clear text when ordering:(only the values ∆p HD shown in the table are possible)High pressure relief valve ADifferential pressure setting: ∆p HD = ... barOpening pressure of the HD-valve (at q V 1 ): p max = ... bar(p max = ∆p HD + p Sp )High pressure relief valve BDifferential pressure setting: ∆p HD = ... barOpening pressure of the HD-valve (at q V 1 ): p max = ... bar(p max = ∆p HD + p Sp )Example for pressure cut-off:Electrical two-position control, EZ1D/EZ2D