Hydraulic Excavator Control System

1) Hydraulic oil temperature control system Most of the power loss of the hydraulic system is converted into heat, causing the oil temperature to rise. As a result, not only the efficiency of the hydraulic system decreases, but also the deterioration of the oil quality is accelerated. According to the information, the service life of the oil will be shortened by half for every 9 degrees increase of the hydraulic oil temperature over 55 degrees. Therefore, the hydraulic oil temperature should be avoided as much as possible.

After the oil temperature control device is combined with the energy-saving control device, it is in an alarm state. When the device is working, first set the hot-melt over-temperature protector within the reasonable temperature range of the system, and then close the magnetic steel temperature limit switch. The temperature control switch is turned off under the control of the function. When the oil temperature rises to the set temperature sensor of the hot melter over-temperature protector, the magnetic steel temperature limit switch is automatically disconnected, and the temperature control switch is pulled in. At the same time, the temperature control indicator light is on, giving an early warning indication. The indicator signal controls the throttle opening of the diesel engine through the operation mode selection switch and the throttle electronic controller of the electronic energy-saving control module, and the speed of the diesel engine is reduced to reduce the flow of the hydraulic pump, control the heat generation of the hydraulic system, and avoid oil The liquid temperature continued to rise.

After the temperature warning is released, the magnetic steel temperature limit pressure switch is pulled in to eliminate the influence of the oil temperature on the electronic energy-saving control module, so that the excavator can return to normal working state.

2) Hydraulic excavator working condition monitoring and fault finding system The hydraulic excavator working condition monitoring and fault finding system plays an important role in improving maintenance methods, ensuring safe operation and eliminating hidden dangers of accidents. The system currently has two forms: one is a diagnostic computer - a handheld terminal that plugs into the on-board system, such as Japan's Hitachi Construction Machinery's Dr.EX fault diagnosis system; the other is a randomly installed system, such as Germany's O&K's working condition control system (BCS), which takes the lead in using satellite communication technology, transmits the technical status and fault location of each excavator in operation from the airborne transmitter to the synchronous satellite, and then the transponder on the satellite transmits it. Back to the maintenance management center, the computer screen of the management center displays the operation status of each excavator in real time.

3) Automatic excavation control system The basic principle of the automatic excavation control system using laser transmitters is to set up a rotary laser transmitter at the construction site, which can control several excavators to operate on the same required datum plane. A laser receiver is installed on the excavator, and there are three light targets on it - the upper and lower light targets and the reference light target. When the laser beam emitted by the laser transmitter just hits the reference light target, the working device of the excavator keeps working on the required ideal working surface. If the change of external factors causes the working device of the excavator to deviate from the required ideal working surface, the laser beam will either shoot on the upper light target or the lower light target, indicating that the working device has deviated. At this time, the upper light target or the lower light target will convert the light signal into an electronic command signal to drive the diverter valve set on the excavator to act, so as to control the flow of hydraulic oil and make the working device of the excavator return to the required ideal working surface again. go to work. The automatic excavation control system using the laser transmitter can greatly reduce the labor intensity of the driver and obtain better excavation work quality.

4) Remote control excavators Remote control excavators refer to excavators that are operated by wired or wireless circuit devices. The general wired remote control distance is 150-300m, and the wireless remote control distance is 1500-2000m.

In the remote control device, the displacement of the joystick is converted into voltage, which is then converted into a digital value by the A/D converter, the parallel signal of each joystick is converted into a series signal, and the wireless motor is used for transmission processing, and the signal is transmitted. onto the excavator. The signal received by the excavator is opposite to the action at the time of transmission, converted into a current value, and the actuator (hydraulic cylinder or hydraulic motor) is activated through the electromagnetic proportional pressure reducing valve. Other actions are also made by the solenoid valve after receiving the wireless signal to make the actuator act.

5) Hydraulic excavator integrated control system

The main features of the hydraulic excavator integrated control system are:

(1) The load-sensing hydraulic system with electronically controlled pressure compensation is adopted. It consists of a load sensing control valve and a load sensing control variable pump. The output flow of the hydraulic pump is always equal to the flow required by the actuators (hydraulic cylinders, hydraulic motors).

(2) An electronically controlled power adjustment system is adopted. This is mainly through the computer to set the power of the engine and the hydraulic pump to determine the engine throttle opening and the displacement of the hydraulic pump. In this way, different engine characteristics and hydraulic pump characteristics can be used according to different working conditions of the excavator, and the characteristic curves are all determined by computer software.

(3) The control system of manual and electronic joint control is adopted. Due to the changeable working conditions of the excavator and the complicated operation, manual operation cannot be separated, but the electronic control plays an important auxiliary adjustment role. For example, the driver can only operate one handle during the entire operation of the excavator, and the rest of the actions are automated interlocking movements. However, the principle of manual priority is adopted, and the automatic control system suspends operation during manual operation.

(4) The hand-held terminal fault diagnosis system is adopted, so that the faults of the excavator can be found and dealt with in time.