Hydraulic valves are among the most critical actuators in hydraulic systems. Their primary function is to control the direction, flow rate, pressure, and speed of hydraulic oil, thereby achieving precise control of mechanical motion.
Simply put, hydraulic valves are like the "brain" and "traffic lights" of a hydraulic system, determining where the hydraulic oil flows, how fast it flows, whether it is blocked, and at what pressure it can pass.
Based on their main functions, hydraulic valves are generally classified as follows:
**Direction Valve:** Function: Changes the direction of hydraulic oil flow, thereby controlling the extension, contraction, or rotation of actuators (such as cylinders or motors).
Characteristics: The most common type of hydraulic valve, typically used in conjunction with an oil tank, pump, and actuator.
**Pressure Valve:** Function: Controls the working pressure within the hydraulic system, preventing excessive system pressure from damaging components.
Characteristics: Usually operates passively, utilizing pressure differences within the system to achieve its function (e.g., safety valves, relief valves).
**Flow Valve:** Function: Regulates the flow rate of hydraulic oil, thereby controlling the speed of actuators. Features: **Hydraulic Valve:** Flow rate is adjusted by changing the resistance of the hydraulic circuit; a common example is the throttle valve.
Proportional Valve:
Function: Adjusts the flow rate or pressure of hydraulic oil proportionally to changes in the input electrical signal, achieving stepless control.
Features: High precision, fast response speed; commonly used in high-precision mechanical equipment.
Servo Valve:
Function: Used in conjunction with a servo motor to achieve higher precision and faster response speed control.
Features: Typically used in high-precision CNC machine tools and aerospace applications.
Structural Features of Hydraulic Valves:
Hydraulic valves typically consist of a valve body, valve core, valve seat, spring (or elastic element), etc. The movement of the valve core opens or closes the hydraulic circuit, thereby controlling the on/off state or direction of oil flow.