闭环电液比例复合控制泵的特性研究和仿真

发布时间：2018-06-15 09:54

本文选题：电液比例 + 轴向柱塞变量泵　；参考：《南华大学》2011年硕士论文

【摘要】：电液比例控制技术是近年发展起来的一种新型液压控制技术,该技术主要利用电信号控制液压信号,使输出与输入成正比,可以方便的对系统的压力和流量进行高精度控制。电液比例变量柱塞泵具有结构紧凑、简化系统设计和便于实现自动控制,众多国内外企业都积极对电液比例轴向变量泵的开的和推广,它的发展使液压系统向高压、高效率、高功率密度方向迈进。为了节约成本,缩短研制周期、分析相关的技术难题,可采用计算机进行仿真,为泵的仿真提供理论依据和参考。电液比例泵是液压系统的动力源,变量柱塞泵可以通过改变泵的排量与负载所需流量相适应,从而实现节能的目的。对变量柱塞泵的压力进行控制,使其与外负载相适应,最终实现流量控制。对变量轴塞泵的压力——流量实现双比例控制,可以更好实现多级压力——流量液压系统的节能要求。本文利用流体力学方程,对闭环电液比例柱塞泵中的各元件建立单独的数学模型。在压力控制与流量控制状态下,对单个模型进行组合简化并得出传递函数框图,分别建立压力控制子系统和流量控制子系统,最后在Simulink中进行仿真,得出其压力控制与流量控制的动态曲线。影响系统压力的主要元件有压力阀及液阻R4。压力阀的结构参数中关系较大的有先导阀直径、弹簧刚度。通过研究液阻大小、压力阀直径、弹簧刚度对压力响应和流量响应的影响,可以得到改善泵的压力动态响应和稳态响应。影响系统流量的主要元件有节流阀和泵。节流阀的开度大小,阀口形状,液阻大小都会对泵的系统压力产生影响。通过仿真可以了解复合控制泵在一些特定状态下的动态特性,为电液比例泵的设计和改进提供理论依据。
[Abstract]:Electro-hydraulic proportional control (EHPC) is a new hydraulic control technology developed in recent years. It mainly uses electric signals to control hydraulic signals, which makes the output proportional to the input, and can easily control the pressure and flow rate of the system with high precision. Electro-hydraulic proportional variable piston pump has compact structure, simplifies system design and facilitates automatic control. Many enterprises at home and abroad are active in opening and popularizing electro-hydraulic proportional axial variable pump. Its development makes hydraulic system high pressure and high efficiency. Move in the direction of high power density. In order to save the cost, shorten the development period and analyze the related technical problems, computer simulation can be used to provide theoretical basis and reference for pump simulation. The electro-hydraulic proportional pump is the power source of the hydraulic system. The variable piston pump can adapt the displacement of the pump to the required flow rate of the load so as to achieve the purpose of energy saving. The pressure of variable piston pump is controlled to fit the external load and the flow control is realized. The double proportional control of the pressure and flow of the variable axial plug pump can better meet the energy saving requirements of the multistage pressure-flow hydraulic system. In this paper, a separate mathematical model of the components in the closed loop electro-hydraulic proportional piston pump is established by using the hydrodynamic equation. Under the condition of pressure control and flow control, the single model is simplified and the block diagram of transfer function is obtained. The pressure control subsystem and the flow control subsystem are established respectively. Finally, the simulation is carried out in Simulink. The dynamic curves of pressure control and flow control are obtained. The main components affecting system pressure are pressure valve and liquid resistance R 4. Among the structural parameters of pressure valve, there are pilot valve diameter and spring stiffness. By studying the effects of hydraulic resistance, pressure valve diameter and spring stiffness on pressure response and flow response, the pressure dynamic response and steady state response of the pump can be improved. The main components affecting system flow are throttle valves and pumps. Throttle valve opening size, valve shape, liquid resistance will affect the pump system pressure. The dynamic characteristics of the compound control pump under some special conditions can be understood by simulation, which provides a theoretical basis for the design and improvement of the electro-hydraulic proportional pump.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137.5

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