CRS2-OHW - Bosch Automotive Technology

Diesel SystemsCommon Rail Systems with upto 2,000 bar for off-highway applicationsCRS2-20-OHWHighpressurepumpTankPre-filterand waterseparatorHigh-pressureFilter +handprimerSensorsLow-pressure circuitRailpressuresensorEDC control unitRailActuatorsSolenoidinjectorPressurelimitingvalveCommon Rail Systems refined specifically foroff-highway operation are robust and powerful,fulfilling the market-specific requirements.Based on the previous generations, Bosch developsoff-highway systems with rail pressures of 1,800 barand 2,000 bar, including a new injector. This injectorhas a fast-switching, pressure-balanced solenoid valveand an integrated additional high-pressure volume.These systems are evolutionary, fully compatibledevelopments which will be in series production in2013.Customer benefits Off-highway qualified systems with 8,000 hlifetime even at a high percentageof full-load operation Contributes towards achieving futureemissions limits (Tier 4, Stage 4) High efficiency even at low engine speeds Easy integration into existing and futureengine platforms Limp-home operation High flexibility in base engine and exhaust-gastreatment design due to high system and injectionpressure High robustness and reduced quantity wavingPossible applicationsThe system family, with a maximum rail pressure of1,800 bar (CRS2-18-OHW) or 2,000 bar (CRS2-20-OHW), was developed first and foremost for use inthe off-highway sector: agricultural and constructionmachines, industrial applications up to 130 kW for4-cylinder engines and up to 200 kW in the case of6-cylinder engines.Operating principleThe Common Rail System family for off-highwayapplications has been developed on the basis ofproven passenger-car system components. In adaptingit for off-highway operation, we have specifically takeninto account rough operating conditions with long periodsof full load operation and large injection quantities.Anti-wear measures for the hydraulic componentsensure a lifetime of about 8,000 operating hours evenwhen using fuel with low lubricity.The injector is capable of holding a high-pressurevolume. This design reduces pressure oscillations,which results in reduced quantity waving. Comparedwith the CRI2-16-OHW the system efficiency has beenincreased by reducing the return flow quantity.

Diesel Systems | Common Rail Systems with up to 2,000 bar for off-highway applicationsTechnical specificationsSystem pressure230 – 2,000 barMax. number of injections 8Hydraulic flow rate250 – 600 cm 3 /30 sOperating voltage12 V/24 VLifetime8,000 hFields of applicationOHWMax. engine power~ 33 kW/cyl. approx.Number of cylinders 3 – 6Emission target Tier 4, Stage 4System components (CRS2-20-OHW as example)12System designThe CP4 high-pressure pump is used for all pressurelevels from 1,600 bar to 2,000 bar. This allows apressure increase without changing the pump drive.The HFR-20 high-pressure rail has a dual-stage pressure-limitingvalve which protects the system fromoverload and offers limp-home operation.The powerful second generation injectors have apressure-balanced solenoid valve and give enginedevelopers a high degree of freedom in designing theinjection pattern. In a very narrow time slot, up toeight single injections per stroke are possible. Thismulti-injection capability contributes to a furtherreduction of fuel consumption and subsequentlyCO 2 output as well as reduced noise and exhaust-gasemissions.34All system functions are monitored and controlled bythe engine control system. The engine control unit alsosupports exhaust-gas treatment systems such asexhaust-gas recirculation and diesel particulate filter.The EDC17 control unit is suitable for chassis mountingor optionally also for engine mounting.1234CP4-20/1-OHW high-pressure pumpHFR-20 high-pressure rail with rail-pressuresensor and dual-stage pressure-limiting valveCRI2-20-OHW solenoid injectorEDC17 control unitOutlookBosch engineers are already involved in the evolutionarydevelopment of this modular system. Futuregenerations will take advantage of this strongfoundation and use it for system pressures over2,500 bar.Bosch: Automotive competence from a single sourceComprehensive range of services and know-howSystem and network competenceInnovator and technology leaderWarrantor for quality and dependabilityWorldwide presenceUniversal partnerRobert Bosch GmbHDiesel SystemsPostfach 30 02 2070442 StuttgartGermanydiesel@bosch.comwww.future-with-diesel.comPrinted in Germany292000P0WG-C/CCA-201209-En© Robert Bosch GmbH 2012. All rights reserved, also regarding any disposal, exploitation, reproduction,editing, distribution, as well as in the event of applications for industrial property rights