SYSTEM / Control System Swing Horsepower Reducing Control Purpose: Decreases delivery flow rate of main pump 2 including the swing circuit, increases delivery flow rate of main pump 1 and uses the en- gine power effectively when the swing con- trol lever is operated and the pressure sen- sor (swing) detects swing pilot pressure. Operation: 1. The pressure sensor (swing) detects swing pilot pressure and sends a signal to MC when the swing function is operated. 2. MC calculates the target pump displacement an- gle according to a signal from the pump delivery pressure sensor.
Then, MC compares the target displacement angle with the actual pump dis- placement angle detected by the pump regulator pressure sensor. 3. MC activates the pump control solenoid valve in main pump 2 in order to compensate the differ- ence between the actual and target displacement angles, and decreases pump delivery flow rate. 4. If the combined operation of swing and travel, or swing and front attachment is operated, the pressure sensors (swing, travel, boom raise/lower, arm roll-out/in, bucket roll-out/in and attachment) detect pilot pressure respectively and send a signal to MC. 5. MC activates the control solenoid valve in main pump 1 and increases pump delivery flow rate.
Q Flow Rate Main Pump 2 Pressure P Q Flow Rate Main Pump 1 Pressure P T2-2-30