Nozzle Baffle Hydraulic Servo System in Hydraulic Press

The working principle of the nozzle baffle hydraulic servo system is shown in Figure 9-8. It consists of a fixed orifice o, an intermediate oil chamber 6
The nozzle 1 and baffle 2 are composed. The nozzle and baffle together form a variable cross-section throttling device. Intermediate oil chamber 6 and execution
The working oil chambers of the components are connected.
Set the pressure oil pressure from the hydraulic pump to p
Over fixed orifice. Afterwards, a portion of the oil passes through the nozzle end
The gap 6 formed by the surface and baffle is discharged and flows back to the fuel tank.
The position of the baffle (i.e. the size of gap 6) is determined by the input signal
It can be controlled directly using mechanical methods, and
It can be controlled by electrical signals when the size of 6 changes,
This changes the throttling effect at the nozzle and baffle, thus
The oil pressure p: in the middle oil chamber also changes accordingly
This causes the actuator to move.
The advantage of the nozzle baffle hydraulic servo system is shown in Figure 9-8. Schematic diagram of the working principle of the nozzle baffle hydraulic servo system
Simple structure, small inertia and displacement of the moving part, reaction 1: nozzle 2: baffle
Fast, high precision and sensitivity, low processing requirements, no radial imbalance force, and no "jamming" phenomenon, thus
More reliable operation. Its disadvantage is that the power loss is large, and the distance between the nozzle baffles is small, resulting in poor anti pollution ability. Therefore, it is advisable to place it in multiple stages
Used as a stage to stage (pre stage) servo device in a large servo system. Specific examples can be seen in the electro-hydraulic servo valve.