Pressure switch's structure and working principle

Pressure switches has plunger type, diaphragm, spring tube types and bellows type 4 structure form, press diaphragm pressure relay structure of the control oil mouth and connected to the hydraulic system. Pressure oil from control into the mouth, the effect on rubber diaphragm, when pressure to achieve spring set pressure, diaphragm deformation, and promote the plunger to rise, at this point, the plunger of the cone push on both sides of the ball along the horizontal hole of coat, the ball and push lever around the hinge axis anticlockwise roll, pressure micro switch touch head, send signals. Adjusting screw can change the spring precompression quantity, so as to change a signal set pressure.

When pressure is reduced to a certain value, the spring make plunger down, the ball into the plunger of the cone slot, loosen the micro switch, random break circuit, the ball in the spring, under the action of the piston can produce certain friction. The force in the plunger upward movement with liquid pressure direction in contrast, in the plunger move in the same direction with fluid pressure. Because of the influence of friction, loosen the micro switch of pressure and pressure under micro switch of low pressure.

Diaphragm pressure relay, because the diaphragm displacement is small, pressure oil volume change small, quick response, repeating precision is high, the hydraulic press general error in the constant pressure of 0.5 1.5, shortcoming is easy to accept the influence of pressure fluctuation in low pressure and vacuum when it is better to use, and should not be used in high pressure system.

Plunger type pressure relay work reliable, long life and low capital. Because the volume change is bigger, it will not be affected by the fluctuation of the pressure. But because spring stiffness is bigger, four column hydraulic press so repeated low precision, error for setting pressure of 1.5-2.5. In addition, the opening pressure and closure pressure is larger difference

Pressure switch of the structure and working principle
Pressure switch  is the use of liquid pressure signal to open/close electrical contact hydraulic electrical switching components, hydraulic press  in a hydraulic pressure to achieve the set pressure, send signals, control electrical element action, realize pump loading or unloading, the implementation of the components of sequential action or happy event with safety protection and interlock control function.



The above: Hydraulic gear pump failure and maintenance