Introduction: the complexity of the wrong pressure relay structure, non-engineering students is difficult to understand its internal structure, and even simply do not even know what this is the pressure relay, in fact, although we do not have much contact with the pressure relay, but a lot of places is the need for it to exist, the pressure relay has a lot of models, the role of the different models of the pressure relay is different, and its internal structure will be There is a big difference, here we explain some of the different pressure relay structure and role of the difference.
Diaphragm pressure relay:
When the pressure of the inlet reaches the adjusted value of the spring, the diaphragm produces a convex deformation under the action of liquid pressure, so that the plunger moves upward. The conical surface of the plunger makes the steel ball and make radial movement, the steel ball pushes the lever around the pin axis counterclockwise deflection, resulting in the end of the pressure down the microswitch, sends out an electrical signal, turn on or off a circuit. When the inlet pressure due to oil leakage or other reasons down to a certain value, the spring makes the plunger move down, the steel ball and fall back into the plunger taper groove, the microswitch reset, cut off the electrical signal, and will push the lever back to disconnect or turn on the circuit.
Single-plunger pressure relay
Control port p and the hydraulic system is connected, when the system pressure rises to the pressure relay set value, the hydraulic pressure acting on the plunger 5 to overcome the spring force, the top lever pushed up, so that the micro switch contacts connected or disconnected; when the system pressure falls below the set value, under the action of the spring force, the top lever and plunger down to reset, the microswitch returns to the
Plunger pressure relays are reliable, long-lasting and low-cost. Because of its large volume change, it is less susceptible to pressure fluctuations. However, due to the spring stiffness, so the repeatability is low, the error is 1.5-2.5 of the adjusted pressure. in addition, the difference between the opening pressure and the closing pressure is large
Spring tube pressure relay
By the shell box cover, pressure-sensitive components, ? pressure switch and a junction box. Characterized by the said pressure-sensitive element is a metal control of the multi-turn spiral spring tube, spring tube ends respectively with the oil inlet connector and sealing plug first threaded and then welded, the oil inlet connector is fixed to the shell, sealing plug is fixed to the adjustable contact plate, the contact plate and the pressure switch? The contact plate is fixed on the sealing plug with adjustable contact plate, the contact plate and the pressure switch? One end of the pressure switch is fixed on the housing, and the distance between the contact plate and the contacts of the pressure switch? is adjusted by a pressure adjusting mechanism.
Bellows type pressure relay
Mainly consists of low-pressure bellows, high 7 low-pressure grieving rod, disc-shaped seniority piece, differential pressure adjustment disk, reset spring, pressure adjustment disk, drive rod and Chet switch and other components. High and low-pressure refrigerant vapor through the connection of bamboo to the pressure relay business, low-pressure corrugated, so that the deformation, and then through the reset spring and drive rod to make the microswitch to connect or disconnect, in order to control the compressor to stop and run, which, the pressure adjustment plate can adjust the reset spring elasticity, and differential pressure adjustment plate can be adjusted to the microswitch when the differential pressure between the disconnection and closure.
Guys, I do not know after reading the four pressure relays you dizzy yet? Intelligent as you, even if dizzy dizzy, but also must be to understand a lot of relevant knowledge. The process of seeking knowledge itself is painful and happy, will take the initiative to understand the knowledge of people, must be able to gain a lot. People can not stop the desire to learn, live to learn old, more involved in some other knowledge do not know can broaden people's horizons, as long as you can harvest some of the editor's purpose has been achieved.