In modern industrial production, cranes, as an important material handling equipment, are widely used in many fields such as buildings, ports and factories. In order to achieve accurate control of lifting equipment, especially in the process of lifting, lowering and positioning, the application of servo valve is particularly important. This paper will focus on how the lifting equipment can achieve efficient and accurate operation by controlling the servo valve.
First, the basic principle of servo valve
Servo valve is a kind of hydraulic control valve with high precision and fast response. Its core function is to accurately control the flow and direction of hydraulic oil according to the input electrical signal (usually from the controller), so as to drive the hydraulic cylinder or hydraulic motor to work. Servo valve is usually composed of electromagnetic coil, nozzle, slide valve, etc. It can convert small electrical signals into high-power hydraulic output, and has high sensitivity and good dynamic response characteristics.
Second, the application of servo valve in lifting equipment
In lifting equipment, servo valves are mainly used to control the actions of lifting mechanism, luffing mechanism and slewing mechanism. The operation requirements of these mechanisms include not only the stability of power output, but also the accurate control of speed and position. For example, in the operation of tower crane or bridge crane, the lifting and falling of the load need to be very stable to prevent the goods from shaking or being damaged, which depends on the high-precision control ability of the servo valve.
Third, the control mode of servo valve
The lifting equipment sends control signals, usually analog voltage or current signals (such as 0-10V or 4-20mA), to the servo valve through PLC (programmable logic controller) or special controller to control the opening and direction of the valve core. The specific control flow is as follows:
1. Signal input: the operator inputs instructions through the operating handle or remote control system;
2. Signal processing: the control system converts the operation instructions into corresponding electrical signals;
3. Servo valve response: the servo valve adjusts the flow and direction of hydraulic oil according to the received signal;
4. Actuator action: the hydraulic cylinder or motor makes corresponding actions according to the change of hydraulic oil;
5. Feedback closed-loop control: the system monitors the position and speed in real time through feedback devices such as encoder and pressure sensor, and adjusts the output of servo valve to ensure accuracy.
Fourth, the advantages of servo valve control
1. High-precision control: the servo valve can realize micron-level position control and is suitable for high-precision lifting operation;
2. Fast dynamic response: short response time, suitable for frequent start-stop and rapid change;
3. Energy saving and high efficiency: reduce the energy loss of hydraulic system through precise control;
4. High safety: closed-loop control ensures that the system can be adjusted in time under abnormal conditions to prevent accidents.
V. Development trend and application prospect
With the continuous improvement of industrial automation level, the intelligent and networked trend of servo valve in lifting equipment is increasingly obvious. Modern lifting equipment has begun to adopt digital servo valve, and combined with Internet of Things (IoT) technology to realize remote monitoring and fault diagnosis. In the future, with the development of artificial intelligence and adaptive control technology, the application of servo valve in lifting equipment will be more extensive and in-depth.
tag
As the core control element in the hydraulic system of lifting equipment, the servo valve’s performance directly affects the control accuracy and operation stability of the equipment. By controlling the servo valve scientifically and reasonably, not only the working efficiency and safety of lifting equipment can be improved, but also the automation level and intelligence level of operation can be significantly improved. Under the background of Industry 4.0, the continuous innovation of servo valve control technology will inject new impetus into the development of hoisting machinery.