The measuring accuracy of the pressure gauge for the hydraulic system of the oil pressure cutting machine is 1.0, 1.6, 2.5 and 4, respectively.O level.The measuring range is generally 0.1 ~ 250 MPa. The low-pressure meter is used for measuring the pressure value of 0 ~ 6 MPa, the medium pressure meter is used for measuring the pressure value of 10 ~ 60 MPa, and the high-pressure meter is used for measuring the pressure value of more than 100 MPa.The installation method of the pressure gauge for hydraulic press is radial installation and axial installation. As shown in table 9-7, the connection diameter of the radial pressure gauge and the dial form I, while the connection diameter of the axial pressure gauge and the dial form T.
Figure 6-2 shows a multi-stage pressure regulating loop with three overflow valves, which can output three levels of pressure for the system.In the figure, the system pressure is regulated by the high-pressure relief valve to obtain the high-pressure pressure. When the left end of the three-position electromagnetic reversing valve is electrified, the system pressure
The first low pressure is obtained by regulating the low pressure relief valve 1. When the right end of the three-position electromagnetic reversing valve is electrified, the system pressure is adjusted by the low pressure relief valve 2 to obtain the second low pressure.This pressure regulating loop control system is simple, but it will produce shock when the pressure is changed.The specifications of the three overflow valves must be selected according to the maximum oil supply of hydraulic pump 4.
Generally there are two forms: one is the use of small friction seal (such as ring and seal), the structure of the hydraulic cylinder has a higher volume efficiency and mechanical efficiency;The other is to use the cone-shaped structure (the small diameter of the cone corresponds to the high pressure, the large end corresponds to the low pressure) to eliminate the clamping force, the piston rod USES the wedge clearance static pressure support, and USES the clearance seal, so that the leakage of oil back to the tank.