As resistance to flow increases, pump discharge (4) pressure increases for any given swashplateposition. The pump displacement self-adjusts to satisfy the flow request at the higher pressures.When pump discharge pressure becomes high enough for the hydraulic horsepower demand toapproach the torque limit of the engine, the ECM limits the system pressure by adjusting the currentto the pump control solenoid to provide as much flow as possible at the engine torque limit. Theengine and pump control software work together to maximize hydraulic horsepower whilemaintaining a steady engine rpm.When the ECM commands maximum current to provide maximum pump flow, swashplate (7) is at maximum angle. Resistance to pump flow causes the pump discharge pressure to rise. When thepump discharge pressure sensor in the main control valve detects pump discharge pressure near or atthe torque limit pressure, the ECM will decrease the current value to the proportional pump controlsolenoid valve (5). The solenoid shifts the spool within the control solenoid valve to a position whichredirects some pump discharge pressure behind actuator piston (8), causing the pump toDESTROKE enough to provide as much flow as possible while maintaining engine speed.Likewise, if during machine operation the system pressure suddenly spikes and the engine begins tolug, the ECM will decrease the current value to the pump control solenoid to destroke the pump andallow the engine to recover to the requested speed.The current value sent to the torque control solenoid can be anywhere from 400-1200 mA,depending on requested engine speed, actual engine speed, oil temperature, and pump pressure.When pump discharge pressure falls below the torque limit pressure and actual engine speed iswithin the target speed range and power band, the ECM will readjust the current to the solenoid toprovide as much flow as possible, within the flow limit of the pump and torque limit of the engine.Note: The ECM calculates the torque limit pressure by considering all flow requests, systempressure, oil temperature, speed dial setting, ambient air pressure, and actual engine speed. All theseinputs allow the maps contained in the ECM software to calculate hydraulic horsepower and theengine’s ability to supply the required torque at any speed dial setting. When the hydraulichorsepower calculation exceeds the engine torque limit, the Machine ECM destrokes the pump tomaximize both hydraulic horsepower and engine power production.
As resistance to flow increases, pump discharge (4) pressure increases for any given swashplateposition. The pump displacement self-adjusts to satisfy the flow request at the higher pressures.When pump discharge pressure becomes high enough for the hydraulic horsepower demand toapproach the torque limit of the engine, the ECM limits the system pressure by adjusting the currentto the pump control solenoid to provide as much flow as possible at the engine torque limit. Theengine and pump control software work together to maximize hydraulic horsepower whilemaintaining a steady engine rpm.When the ECM commands maximum current to provide maximum pump flow, swashplate (7) is at maximum angle. Resistance to pump flow causes the pump discharge pressure to rise. When thepump discharge pressure sensor in the main control valve detects pump discharge pressure near or atthe torque limit pressure, the ECM will decrease the current value to the proportional pump controlsolenoid valve (5). The solenoid shifts the spool within the control solenoid valve to a position whichredirects some pump discharge pressure behind actuator piston (8), causing the pump toDESTROKE enough to provide as much flow as possible while maintaining engine speed.Likewise, if during machine operation the system pressure suddenly spikes and the engine begins tolug, the ECM will decrease the current value to the pump control solenoid to destroke the pump andallow the engine to recover to the requested speed.The current value sent to the torque control solenoid can be anywhere from 400-1200 mA,depending on requested engine speed, actual engine speed, oil temperature, and pump pressure.When pump discharge pressure falls below the torque limit pressure and actual engine speed iswithin the target speed range and power band, the ECM will readjust the current to the solenoid toprovide as much flow as possible, within the flow limit of the pump and torque limit of the engine.Note: The ECM calculates the torque limit pressure by considering all flow requests, systempressure, oil temperature, speed dial setting, ambient air pressure, and actual engine speed. All theseinputs allow the maps contained in the ECM software to calculate hydraulic horsepower and theengine’s ability to supply the required torque at any speed dial setting. When the hydraulichorsepower calculation exceeds the engine torque limit, the Machine ECM destrokes the pump tomaximize both hydraulic horsepower and engine power production.<br>
正在翻译中..