​Basic Pressure Control Circuits of Hydraulic Multifunctional Drilling Rig

Basic Pressure Control Circuits of Hydraulic Multifunctional Drilling Rig

The basic pressure control circuit is critically important, as it provides the force and torque required by the actuators of the Hydraulic Multifunctional Drilling Rig. The core component used in this circuit is the pressure control valve, which regulates the hydraulic pressure. The basic pressure control circuit plays a vital role in the operation of the Hydraulic Multifunctional Drilling Rig.

Balancing Circuit  

In practical engineering, the vertical hydraulic cylinder of the Hydraulic Multifunctional Drilling Rig may descend due to its own gravity. To prevent this, a balancing circuit can be employed. Such circuits are commonly used in mechanisms like unbalanced luffing, lifting, and telescoping mechanisms in cranes, as well as gravity descent mechanisms such as plungers, pistons, and slider mechanisms in hydraulic presses. Balancing circuits include:

(1) Balancing circuit using a check sequence valve for support and speed limiting control.

(2) Balancing circuit using a check throttle valve for speed limiting and a hydraulic-controlled check valve for locking.

Pressure Maintaining Circuit

As the name implies, a pressure maintaining circuit keeps the pressure constant, maintaining a specified pressure during a certain phase of the work cycle. This type of circuit has three main characteristics:

(1) Stable pressure  

(2) Reliable operation  

(3) Energy efficiency.  

Pressure Reducing Circuit

A pressure reducing circuit lowers the pressure of the hydraulic circuit. This is achieved through the coordination of a pressure reducing valve with other valves. With this circuit, a stable pressure lower than the pump’s supply pressure can be obtained.

Pressure Regulating Circuit

The function of a pressure regulating circuit is to maintain the pressure of the entire hydraulic system of the Hydraulic Multifunctional Drilling Rig or a specific section at a constant value or below a certain limit. Pressure regulating circuits include:

(1) Single-stage pressure regulating circuit

(2) Multi-stage pressure regulating circuit

(3) Stepless pressure regulating circuit.

Pressure Intensifying Circuit

A pressure intensifying circuit is used to increase the pressure of the hydraulic system in the Hydraulic Multifunctional Drilling Rig. By using this circuit, a hydraulic pump with a relatively low output pressure can be used to obtain higher-pressure oil. Additionally, compressed air can be used as a power source to achieve the same effect. An intensifier is an essential component in this circuit, which includes:

(1) Single-acting intensifier

(2) Double-acting intensifier.

Unloading Circuit

The function of an unloading circuit is to allow the hydraulic pump to operate under nearly no pressure. The advantages of an unloading circuit include:

(1) Avoiding frequent starting of the motor

(2) Reducing heat generation in the hydraulic system of the Hydraulic Multifunctional Drilling Rig

(3) Minimizing power loss

(4) Extending the service life of the motor and pump.

Commonly used unloading circuits include:

(1) Unloading circuit using an externally controlled sequence valve as the unloading valve

(2) Unloading circuit using a bypass with a two-way, two-position valve

(3) Unloading circuit using a pilot-operated relief valve

(4) Unloading circuit utilizing the neutral position function of an M (or H, K) type directional valve.