附件24.4 9 Mechanical efficiencyn m (%) Note:The pressure P of the test pump can be selected in the range of 0~70kgf/cm 2 within Interval 10kgf/cm2.Make two measurements for each point of the contents and respectively recorded in the table a,b Experiment 5 Experiment of increased-speed circuits 1.The purpose of the experiment Some mechanical transmission mechanism need two kinds of velocity:For the fast velocity,It requires large flow rate and low pressure.While the velocity is slow,the situation is on the contrary exactly.Differential circuit can be used to avoid a great amount of hydraulic oil overflowing back to the tank from the relief valve when the mechanism moves slowly,causing large power loss and temperature rise. 2.Differential circuit diagram and requirements of Condition of the action A differential circuit is shown in Figure 1 and Action sequence of conditions shown in Figure 2. 3.Experimental procedure (1)According to the differential circuit diagram,select hydraulic components and check whether the model is correct or not (2)Hydraulic components should be installed in the test table on the board and arranged in a suitable location and then connect circuit which is shown in the circuit diagram into a differential circuit by using the hoses and quick joints (3)Process numbers for all solenoid directional valve and position limit switch and correspond them to the number plate mount to avoid making mistake. 14 附件 24.4 14 9 Mechanical efficiencyη m （ %） Note: The pressure P of the test pump can be selected in the range of 0 ~ 70kgf/cm 2 within Interval 10kgf/cm 2 . Make two measurements for each point of the contents and respectively recorded in the table a, b Experiment 5 Experiment of increased-speed circuits 1. The purpose of the experiment Some mechanical transmission mechanism need two kinds of velocity: For the fast velocity, It requires large flow rate and low pressure. While the velocity is slow , the situation is on the contrary exactly . Differential circuit can be used to avoid a great amount of hydraulic oil overflowing back to the tank from the relief valve when the mechanism moves slowly ,causing large power loss and temperature rise. 2. Differential circuit diagram and requirements of Condition of the action A differential circuit is shown in Figure 1 and Action sequence of conditions shown in Figure 2. 3. Experimental procedure (1) According to the differential circuit diagram, select hydraulic components and check whether the model is correct or not. (2) Hydraulic components should be installed in the test table on the board and arranged in a suitable location and then connect circuit which is shown in the circuit diagram into a differential circuit by using the hoses and quick joints (3) Process numbers for all solenoid directional valve and position limit switch and correspond them to the number plate mount to avoid making mistake