Nowadays, the complex and diverse circuits in excavators are due to the rapid development of excavators in circuit and hydraulic pressure. Excavator circuits can be classified in different ways according to electrical components and networks. This article will briefly introduce the circuit of excavator.
According to the correlation of the circuit composed of various components, it can be divided into associated circuit and non associated circuit.
1. Uncorrelated circuit: the so-called uncorrelated circuit refers to a simple circuit composed of only a few electrical components: this kind of circuit is neither used as the signal source of other circuits nor as the signal source of other circuits. Its existence and operation have no impact on other circuits and components, but there are fewer and fewer such circuits. For example:
1) Lighting: components include switches, relays, lamps, etc
2) Horn: components include switch, relay, horn, etc
3) Traveling speed: components include switch, relay, solenoid valve, etc
4) Various liquid levels (it seems that some of these are also related):
2. Associated circuit: Contrary to non associated circuit, in the associated circuit, each circuit is not independent. They either take the external signal as the source signal or the signal collected by themselves as the control source signal of other circuits.
Since this method is not easy to understand, I will not make too much explanation here.
According to its function, it can be divided into display system and control system.
1. Display system: this kind of system is mainly used for the manipulator in driving to know the operation condition of the machine in time. Its main components are mostly sensors, instruments and indicator lights, mainly including:
1) Water temperature
2) Water level
3) Oil pressure
4) Oil level
5) Fuel level
6) Air
7) Hydraulic oil level
8) Generating electricity
9) Various working modes, etc.
2. Control loop: the so-called control loop refers to a loop in which one or several components change the working state of a mechanism after processing based on the signals collected by other components. There are signal acquisition elements, processing elements and executive elements in the circuit. Signal acquisition elements can be divided into automatic acquisition and manual input.
This control loop can be divided into engine control system, hydraulic pump control system, valve control system and other control systems according to its control objects.
1) Engine control system: in this control system, the actuating elements include starting motor, EC motor (stepping motor), and some machines also have parking motor or parking relay. Signal processing element is what we often call computer or ECU. Signal acquisition elements include start switch, throttle knob, speed sensor, EC sensor, pressure switches, etc. Some also take the water temperature, oil pressure, water level and oil level as the source signal of engine control.
2) Hydraulic pump control system: in the hydraulic pump control system, the only actuator is the pump control solenoid valve. Its processing element is computer PVC. Its source signal acquisition components are also relatively few, including engine speed sensor, throttle knob and working mode switch. In most cases, this system is used as an auxiliary system. In some designs, the output pressure of the pump is also used as the source signal. The hydraulic pumps of common excavators are mainly controlled by hydraulic pressure and realized by hydraulic standby system. The main pressure of the system is the main signal source.
3) Valve control system: most of the valve control systems take the manual switch and the pressure switch of the pilot operating system as the signal source, and the relay and solenoid valve as the actuator. Most of their functions are to control the flow distribution.
4) Other control systems: such as light, horn, wiper, etc. are no different from other construction machinery.
