The hydraulic system consists of two parts: signal control and hydraulic power. The signal control part is used to drive the control valve action in the hydraulic power part.
The hydraulic power part is represented by a circuit diagram to indicate the interrelationships between different functional components. The hydraulic source contains a hydraulic pump, an electric motor, and hydraulic auxiliary components; The hydraulic control section contains various control valves used to control the flow rate, pressure, and direction of the working fluid; The execution part contains hydraulic cylinders or hydraulic motors, which can be selected according to actual requirements.
When analyzing and designing practical tasks, block diagrams are generally used to display the actual operating conditions of the equipment. Hollow arrows represent signal flow, while solid arrows represent energy flow. The action sequence in the basic hydraulic circuit includes the direction change and spring reset of the control element (two position four-way reversing valve), the extension and retraction of the actuator element (double acting hydraulic cylinder), and the opening and closing of the relief valve. For the execution and control components, the presentation is based on corresponding circuit diagram symbols, which also prepares for introducing circuit diagram symbols.
According to the working principle of the system, you can sequentially number all circuits. If an execution element number is 0, the control element identifier associated with it is 1. If the component identifier corresponding to the extension of the executing element is even, then the component identifier corresponding to the retraction of the executing element is odd. Not only should hydraulic circuits be numbered, but actual equipment should also be numbered to detect system failures.
The DIN ISO1219-2 standard defines the numbering composition of components, which includes the following four parts: equipment number, circuit number, component identifier, and component number. If there is only one type of device in the entire system, the device number can be omitted.
In practice, another numbering method is to consecutively number all components in the hydraulic system, and in this case, the component numbers should be consistent with the numbers in the component list. This method is particularly suitable for complex hydraulic control systems, where each control circuit corresponds to its system number.
