原文：
           1、前言 超高压气动减压阀是气动刹车系统的重要元件。因为气体粘度小，容易泄漏，而且系统工作压力高，阀的输入压力为11～13MPa，最高输出压力为7MPa，所以，阀的密封性和耐久性成为突出的问题。这里介绍的超高压气动减压阀突破了传统结构［1］，且对重要零、组件进行了优化设计，使得阀在高压情况下无泄漏，其它性能也都满足了使用要求。

           2、工作原理 超高压气动减压阀的工作原理如图1所示。当压头无外力作用时，气源来的气体由输入口进入阀体下部气室，进气阀门在气压和复位弹簧的作用下与进气阀门座压紧，阀输出口无气体输出。当压头受外力F作用时，压头下移，通过平衡弹簧压缩复位弹簧1，将排气阀门压下与排气阀门座接触，使输出口与大气隔离，压头继续下移，顶开进气阀门，压缩空气由进气阀门控制的通道进入阀后面的执行元件气缸。随着气缸压力的增加，进气阀门的开度逐渐减小，直到输出口压力p2与压头上的作用力相平衡时进气阀门关闭。当外力消除后，进气阀门在气压和复位弹簧2的力作用下，向上移动关闭。与此同时，压头与排气阀门在复位弹簧1的力及排气压力的作用下复位，排气口开启，原输出的气体由排气阀门经消声器排入大气。 图1 结构工作原理图 现在再来研究排气阀门处于某一平衡位置时的状态。忽略压头、排气阀门等的重力和摩擦力，排气阀门受力平衡方程为： F＝p1A1＋p2（A2－A1）＋Fs＋Ff（1） 式中：Fs――两个复位弹簧的弹力之和； Ff――密封圈的摩擦力； A1、A2――分别为进、排气阀门的有效受压面积， A1＝π（d12－d012）/4， A2＝π（d22－d022）/4； d――排气阀门座直径； d01――顶杆下段直径； d02――顶杆上段直径。 由式（1）知，阀的输出压力p2与压头上的作用力F成比例(见图4)。

            3、设计和计算 设计超高压气动减压阀一般是先根据给定的设计参数和工作条件，选择阀的结构型式，然后进行结构参数的选择和计算。 通常给定的参数有：气源压力、自力式控制阀阀最大输出压力、通气能力、最大操纵力和行程等。设计和计算的内容有：选择的结构型式，据通气能力和工作压力确定阀的结构尺寸，据行程和操纵力设计平衡弹簧等。 阀的结构设计重点在于进气阀门、排气阀门和活门座的密封结构，因为气体粘度小，且工作压力高，容易泄漏。阀的结构见图1。

           (1)通气能力计算 阀的通气能力是指在给定的气源压力、阀输出压力、执行元件气缸及阀后管道的容积的情况下，阀的充气、排气时间。 通气能力取决于进气通道和排气通道的面积。气动调节阀阀在充气和排气过程中时间很短，我们忽略热交换的影响，即绝热充气和绝热排气。另外，根据阀的工作压力，阀是以音速充气和音速排气。因此阀的进气通道有效面积Aa按下式计算［2］： 式中：V――充气总容积； K――比热比，绝热充气时，K＝1.4； T――空气的温度，标准空气的温度T＝293.15K； t1――充气时间； R――气体常数，R＝287.1N*m/kg/K； p1――阀输入口压力； p2――阀输出口压力； p20――气缸内在充气开始前的压力。 ∵A1=Aa ∴根据结构(见图1和图2)，进气孔直径 按等面积原理，进气阀门与阀门座的轴向距离(开度) hc≥（d12－d012）/（4d1）（4） 放气通道有效面积按下式计算 式中：t2――排气时间； p20――气缸内排气初始压力； pa――外界压力。 其它符号意义同式(3)。 放气孔直径(见图1和图2) 放气阀门与阀门座的轴向距离(开度) h2≥（d22－d022）／（4d）（7） (2)排气阀座直径的计算 由阀的工作原理知道，自力式调节阀排气阀门座直径d的大小直接影响阀的调压精度。若其直径大，则阀的调压精度高；反之，则阀的调压精度低。

           但是，排气阀门座直径又受到操纵力的限制。排气阀门座直径(见图3(b))可由式(1)得到 式中：Fmax――给定的最大操纵力。 在满足操纵力值的前提下，排气阀门座直径尽可能取大值。 (3)进、排气阀门的设计 进、排气阀门的设计主要包括结构型式、材料的选取和几何尺寸的确定。阀门结构采用金属包胶阀门(所谓金属包胶阀门就是将橡胶直接硫化在金属骨架上)。它利用了橡胶材料弹性高和密封比压低的优点，使阀门在工作过程中具有良好的补偿功能；另外利用了金属材料的强度和刚度。阀门加工制造工艺性好，制造成本低廉。 橡胶材料的选择主要根据其机械性能和阀的工作温度。 硫化橡胶的厚度根据阀门座型面高度h选取，橡胶压缩量在(20～25)%为宜。 进、排气阀门的金属骨架宜用黄铜，因其与橡胶的结合性能好。 (4)进、排气阀门座型面的设计 阀门座型面与阀门的橡胶面直接接触，水力控制阀在工作过程中使胶面变形，起密封作用，而且对阀的寿命影响很大。阀门座型面结构如图2所示(其中：图2(a)为进气阀门座，图2(b)为排气阀门座)。图中高度h范围内为阀门座型面，R为密封面。R值小，阀的灵敏度高；R值大，阀的寿命长。经优化设计，R在0.3～0.5范围内取值较好。阀门座型面的粗糙度同样也影响阀的密封性和寿命，粗糙度Ra应不大于0.4μm 图2中b为支承面。它是用来限制胶面过度变形，起保护胶面的作用。

       (5)平衡弹簧的设计 根据阀的性能分析，平衡弹簧与排气阀门座直径一样，直接影响阀的调压精度。减压弹簧的刚度越小，阀的调压精度越好。但是刚度太小，弹簧行程过长。它受到给定行程的限制，应根据给定的参数设计弹簧刚度： k=Fmax/(h1+h2)(9) 有了弹簧刚度、弹力和行程，电动执行器便可进行弹簧的设计了。两个复位弹簧的刚度可设计成相同，而且，其刚度小于平衡弹簧的刚度。

        4、试验 为检验阀的性能，设计试验系统原理图如图3所示。 阀的输出压力与操纵力的关系见图4。图5是在气罐容积为2L，输入压力的11MPa，在压头上迅速施加(除去)操纵力的工况下，阀的充(排)气特性。经过试验和应用，阀的各项技术性能符合要求，有些指标超过同类产品。而且具有结构简单、紧凑、体积小、重量轻、寿命长、可维护性好等特点。

“ The working principle of high pressure pneumatic valve and Optimal Design ”是由中国减压阀网提供的阀门行业新闻，译文仅供参考。另外，中国减压阀网还提供相关产品搜索： 氢气减压阀、 氮气减压阀、 氧气减压阀、 空气减压阀、 更多减压阀产品 等。

译文：
            1 Introduction High pressure pneumatic valve is a pneumatic brake system's important components. Because the gas viscosity, easy to leak, and the system of high working pressure, valve input pressure 11 ~ 13MPa, the maximum output pressure 7MPa, therefore, valve sealing and durability to become an outstanding problem. High pressure pneumatic valve presented here breaks through the traditional structure of [1], and on the key parts, components, optimized design, enables high-pressure valve in case of no leakage, and other properties also meet the requirement. 2 works The working principle of high pressure air valve shown in Figure 1. When the pressure head when no external force, gas source to the gas input into the body by the lower chamber, intake valve and the reduction in air pressure under the action of the spring and compress the intake valve seat, no gas output valve output . When the pressure head by the role of external force F, pressure head down, through the balance of return spring, a compression spring, the exhaust valve and exhaust valve seat pressure contact with the atmosphere to output isolation, continued downward pressure head, Top entered the gas valves, compressed air from the intake valve control channel back into the valve actuator cylinder. With the increase of cylinder pressure, intake valve opening gradually decreases until the output pressure p2 pressure head of forces and equilibrium, the intake valve closed. When the external force removed, the intake valve in the pressure and reset the force of spring 2, the upward closure. At the same time, pressure head and the exhaust valve return spring, one in force and effect of discharge pressure reduction, the exhaust port opens, the original output of gas from the exhaust valve into the atmosphere through muffler. Figure 1 Schematic structure of the work Now consider a balance of exhaust valve position in the state. Ignore pressure head, exhaust valves of gravity and friction, exhaust valve by the force balance equation is: F = p1A1 + p2 (A2-A1) + Fs + Ff (1) The formula: Fs - the two elastic springs and reset; Ff - the friction ring; A1, A2 -, respectively inlet and outlet valves of the effective pressure area, A1 = π (d12-d012) / 4, A2 = π (d22-d022) / 4; d - diameter of the exhaust valve seat; d01 - lower mandril diameter; d02 - diameter of the upper mandril. From (1) knowledge, valve output pressure p2 and the pressure head is proportional to the force F (see Figure 4). 3, design and calculation High pressure pneumatic valvePneumatic and electric diaphragm pumps design is generally the first according to the given design parameters and working conditions, selection valve structure type, then the choice of structural parameters and calculated. Usually given parameters are: supply pressure, valve maximum output pressure, ventilation capacity, maximum operating force, and itineraries. Design and calculation includes: choice of structure type, according to capacity and working pressure ventilation to determine the structure of valve size, stroke and control force, according to the design balance springs. Focus on the structural design of valve intake valves, exhaust valves and valve seat seal structure, because of gas viscosity, and high working pressure, prone to leaks. Valve structure shown in Figure 1. (1) Ventilation Capacity Vent valve is in a given air supply pressure, valve output pressure, the valve actuator cylinder and the volume of pipeline case, the pneumatic valve, exhaust time. Capacity depends on the ventilation intake and exhaust channel channel area. Inflation and exhaust valves in the course of time is very short, we ignore the impact of heat exchange, namely inflation and the adiabatic exhaust insulation. Also, according to the working pressure valve, pneumatic valve based on the speed of sound and exhaust sound. Therefore, the intake valve effective area Aa channel calculated by the formula [2]: The formula: V - total volume of inflation; K - specific heat ratio, adiabatic inflated, K = 1.4; T - air temperature, the standard air temperature T = 293.15K; t1 - Inflatable time; R - gas constant, R = 287.1N * m / kg / K; p1 - pressure valve input port; p2 - valve outlet pressure; p20 - the inner inflatable cylinder pressure before the start. ∵ A1 = Aa ∴ According to the structure (see Figure 1 and Figure 2), into the pore diameter By equal-area principle, intake valves and valve seat of the axial distance (opening) hc ≥ (d12-d012) / (4d1) (4) Deflation channel effective area determined by the formula The formula: t2 - exhaust time; p20 - the initial pressure cylinder exhaust; pa - external pressure. Other symbols used in the same style (3). Put stomatal diameter Sweage pumps &Sludge pumps(see Figure 1 and Figure 2) Deflation valve and valve seat of the axial distance (opening) h2 ≥ (d22-d022) / (4d) (7) (2) calculating the diameter of the exhaust valve seat The working principle that the valve, exhaust valve seat diameter d directly affects the size of the pressure regulator valve precision. If the diameter of large, high precision pressure regulator valve; the other hand, the low precision pressure regulator valve. However, the exhaust valve seat diameter, has been operating force limit. Exhaust valve seat diameter (see Figure 3 (b)) by equation (1) be Type in: Fmax - maximum control force given. Value in meeting the operating force under the premise of the exhaust valve seat diameter as large-value. (3) into the exhaust valve design Inlet and outlet valves include the design of the structure type, material selection and geometry determination. Valve structure of metal coated valve (the so-called metal coated valve is to direct vulcanization of rubber on the metal frame). It uses the high elasticity of rubber materials and sealing advantages than down, so that the valve in the course of their work with good compensation; Another advantage of the strength and stiffness of metal materials. Valve processing and manufacturing technology, good manufacturing costs low. Rubber material of choice is primarilySlurry pumps based on its mechanical properties and the valve operating temperature. Vulcanized rubber, the thickness of the valve seat under the surface height h selection, rubber compression in the (20 ~ 25)% is appropriate. Inlet and outlet valves of the metal skeleton of brass is preferred, because of its good performance with a combination of rubber. (4) into the exhaust valve seat surface design Valve seat surface and direct contact with the valve rubber surface, in the work process, to set plastic surface deformation, seal, and a great influence on the life of the valve. Valve seat surface structure shown in Figure 2 (where: Figure 2 (a) for the intake valve seat, Figure 2 (b) for the exhaust valve seat). Height h within the figure for the valve seat surface, R is the sealing surface. R value is small, Multi-stage pumpssensitive valve; R value of large, long life valve. Optimized design, R in the range of 0.3 to 0.5 is better value. Valve seat surface roughness also affect the life of the valve seal and the roughness should be less than 0.4μm Ra Figure 2 b for the bearing surface. It is used to limit excessive plastic surface deformation, the role of protective plastic surface. (5) the design of the spring balance According to Valve's performance analysis, balance spring and the diameter of the exhaust valve seat, as the pressure regulator valve directly affect accuracy. Decompression of the smaller spring stiffness, the better the precision pressure regulator valve. But the stiffness is too small, spring travel is too long. It is given by the travel restrictions, the parameters should be designed according to the given spring stiffness: k = Fmax / (h1 + h2) (9) With the spring stiffness, elasticity, Other pumpsand stroke, the spring can be designed. Two reset spring stiffness can be designed the same, but its stiffness is less than the stiffness of the spring balance. 4, test In order to test valve performance, design test system schematic shown in Figure 3. Valve output pressure and the relationship between the manipulative force shown in Figure 4. Figure 5 is a cylinder volume of 2L, input pressure of 11MPa, quickly put his head in the pressure (to remove) manipulation of power condition, the valve of the full (row) gas properties. After testing and application of valves to meet the requirements of the technical performance, and some indicators than similar products. And simple structure, compact, small size, light weight, long life, maintainability is good.

原文来源：http://www.1jianyafa.com/

2010-09-01 07:18

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