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逻辑控制系统的设计工作分两个步骤:一是逻辑综合,即按逻辑要求综合出正确的逻辑表达式;二是网络设计,即根据元件的各种性能参数,如切换压力、返回压力、响应频率等,正确地配置元件。这样才能获得实用的控制网络。元件的负载能力是网络设计阶段中不容忽视的重要参数之一。所谓元件的负载能力,就是指在维持网络逻辑功能正常的前提下,一个元件的输出所能带动的下级元件个数和状况的最大极限。在晶体管数字电路中,把一个元件的输出能同时带动下一级同类元件的个数定义为“最大扇出系数”。在流体逻辑中,由于管路中气阻、气容数值的大小及其分布情况十分复杂,评述元件的负载能力时,不仅要讨论其扇出系数,还必须考虑信号的延迟时间、排气时间等许多因素。除了高压膜片式元件和一部分传感器之外,气动元件的负载都是一些容积稍有变化的盲端。如果能绝对排除泄漏,从理论上讲气动元件的扇出系数是无穷大的。负载(闭室容积)加大,会延长压力回升时间,然
Logic control system design work is divided into two steps: First, the logical synthesis, that is, the logical synthesis of the correct logical expressions; second is the network design, that is, according to various performance parameters of the components, such as switching pressure, return pressure, response Frequency, etc., correctly configure the components. In order to get a practical control network. The load capacity of components is one of the important parameters that can not be ignored in the network design stage. The so-called load capacity of components refers to the maximum limit of the number of subordinate components and conditions that can be driven by the output of one component under the premise of maintaining the normal logic function of the network. In the transistor digital circuit, the output of an element can simultaneously drive the next level of the same type of element is defined as the “maximum fan-out factor.” In the fluid logic, due to the complexity of the gas resistance and gas volume values in the pipeline and its distribution, when evaluating the load capacity of components, not only the fan-out coefficient, but also the signal delay time, exhaust time Many other factors. In addition to the high-pressure diaphragm components and some of the sensors, the pneumatic components are loaded with some slight changes in the blind end. If we can absolutely rule out the leakage, theoretically speaking, the fan-out coefficient of pneumatic components is infinite. Load (closed chamber volume) increased, will increase the pressure rise time, of course