The Design Of Hydro-pneumatic Suspension System For All Terrain Crane

The hydro-pneumatic suspension (HPS) technology that appeared in 1970s is a new type of suspension. The HPS can meet the demands of ride comfort and handing stability of the engineering vehicles because it's excellent non-linear stiffness and damping characteristics. With inert gases N₂ as spring and oil as force translation medium, the HPS is a kind of passive suspension which integrating the spring unit and shock absorber. As a consequence, the HPS have not only performances of traditional passive suspension, but also comprehensive performances of slow active suspension. HPS is a key technology to develop the modern engineering vehicles, and it has enormous potential market as well as broad industrial application prospects.This paper selects the HPS system of a practical engineering vehicle as object for analysis and research, and establishes the physical model of hydro-pneumatic cylinder through properly simplifying its practical structure according to its working elements. Depending on hydrodynamics, BWR equation of real gas and the first law of thermodynamics etc., the thesis establishes the thermo-mechanically coupled model for HPS, and on the basis of the model, studies the force-displacement characteristics, force-velocity characteristics and non-linear stiffness and damping characteristics, analyzes the affection disciplines of parameters such as excitation parameters, structural parameters and working parameters on characteristics of HPS system.The simulation results provide a theoretical foundation for independently developing and designing HPS system and a basis for evaluating the whole vehicle performance.The paper mainly includes the following contents:â‘ The hydro-pneumatic suspension (HPS) system of LTM1160 all terrain crane was took as research object. The paper instructed the structural form and working principles of HPS with dual gas-accumulators and established the physical model of hydro-pneumatic cylinder through properly simplifying its practical structure.â‘¡According to the physical model and the working elements of HPS with dual gas-accumulators, depending on hydrodynamics, BWR equation of real gas and the first law of thermodynamics etc., the thermo-mechanically coupled non-linear mathematical model for HPS is built up. On the basis of the model, by using the simulation software ADAMS/view, the paper sets up the modeling of the hydro-pneumatic suspension cylinder. On the base of the parameter model of hydro-pneumatic suspension cylinder established in ADAMS/view, simulates the work characteristics and the change law of internal parameters of the HPS cylinder such as under the external sine excitation. Simultaneously the dissertation puts forward using displacement-force and velocity-force to describe the dynamic characteristics of the HPS, and simulates the affection of the excitation parameters such as amplitude and frequency, structure parameters such as orifice diameter and cylinder internal diameter and rod diameter etc.â‘¢The thesis deduce the mathematical model presented by a series of equations between damping force and elastic force of HPS from the HPS physical model and mathematical model, which supports that HPS has essentially non-linear rigidity characteristic and non-linear damping characteristic. By means of the computer simulation, the paper studies the affection of the key structure and working parameters on the stiffness and damping characteristics. All of these can be treated as the theoretical base to select the parameters and design the HPS.â‘£The hydro-pneumatic suspension (HPS) system of LTM1160 all terrain crane was took as research object,analyses the feasibility that the data transfers in control logic modules by the CAN bus system on the CAN open standard agreement, masters the method that programmes in PLC(programmable logic controller) and the demand on hardware allocation.