【正文】 ent with the list of numbers. This method is particularly applicable to plex hydraulic control 28 system, each control loop are the corresponding number with the system With mechanical transmission, electrical transmission pared to the hydraulic drive has the following advantages: 1, a variety of hydraulic ponents, can easily and flexibly to layout. 2, light weight, small size, small inertia, fast response. 3, to facilitate manipulation of control, enabling a wide range of stepless speed regulation (speed range of 2020:1). 4, to achieve overload protection automatically. 5, the general use of mineral oil as a working medium, the relative motion can be selflubricating surface, long service life。 militaryindustrial control devices used in artillery, ship anti rolling devices, aircraft simulation, aircraft retractable landing gear and rudder control devices and other devi ces. A plete hydraulic system consists of five parts, namely, power ponents, the implementation of co mponents, control ponents, auxiliary ponents and hydraulic oil. The role of dynamic ponents of the original motive fluid into mechanical energy to the pressure that the hydraulic system of pumps, it is to power the entire hydraulic system. The structure of the form of hydra ulic pump gears are generally pump, vane pump and piston pump. Implementation of ponents (such as hydraulic cylinders and hydraulic motors) which is the pressure of the liquid can be converted to mechanical energy to drive the load for a straight line reciprocating movement or rotational movement. Control ponents (that is, the various hydraulic valves) in the hydraulic system to control and regulate the pressure of liquid, flow rate and direction. According to the different control functions, hydraulic pressure control valve can be divided into valves, 27 flow control valves and directional control valve. Pressure control valves are divided into benefits flow valve (safety valve), pressure relief valve, sequence valve, pressure relays, etc.。 the speed of an actuator depends on how much oil is pumped into it per unit of time. It is possible to regulate flow with a variable displacement pump, but in many circuits it is more practical to use a fixed displacement pump and regulate flow with a volume control valve. Flow Control Methods There are three basic methods of applying volume control actuator speeds. They are meterin, meterout and bleedoff. MeterIn Circuit In meterin operation, the flow control valve is placed between the pump and actuator. In this way, it controls the amount of fluid going into the actuator. Pump delivery in excess of the Metered amount I diverted to tank over the relief valve. With the flow control valve installed in the cylinder line as shown, flow is controlled in one direction. A check valve must be included in the flow control or placed in parallel with it for return flow. If it is desired to control directional valve. The method is highly accurate. It is used in applications where the load continually resists movement of the actuator, such as raising a vertical cylinder under load or pushing a load at a controlled speed. 24 MeterOut Circuit Meterout control is used where the load might tend to run away. The flow control is located where it will restrict exhaust flow from the actuator. To regulate speed in both directions, the valve is installed in the tank line from the directional valve. More often control is needed in only one direction and it is placed in the line between the actuator and direction valve. Here too a bypass check valve would be required for a rapid return stroke. BleedOff Circuit In a bleedoff arrangement, the flow control is bleed off the supply line from the pump and determines the actuator speed by metering a portion of the pump delivery to tank. The advantage is that the pump operates at the pressure required by the work, since excess fluid returns to tank through the flow control instead of through the relief valve. Its disadvantage is some less of accuracy because the measured flow is to tank39。 元件選型感觸最深，第一次我選擇的元件很多，很雜，在畫裝配圖時，怎么也組合不起來，很是納悶！仔細觀察油孔布置之后發(fā)現(xiàn)力氏樂的六通徑和油研的六通徑空位置不一樣。進油管長度為 3m，沿程壓力損失 1P? 為： PaPavdlP 6222111 2 ?????????? ??? 閥的壓力損失 PaP ??? 閥 ；那么進油路總的壓力損失 進P?為： 進P? = 1P? + 閥P? = PaPa 666 )( ????? 由于進出口管徑相同，要求工作速度相同，所以估算壓力損失也相同，那么回油壓力損失 也為 兆帕； △ p=+= 20 其他元件可以看成是和主缸并聯(lián)的，入出口輥道升降液壓缸速度比較高，做一驗算，其他元件忽略。 液壓機的執(zhí)行件有兩個，即：主缸和 平衡 缸。 即： M P aPP ??? 通過計算，泵的工作壓力 Pp=。==4mm ④ 給入出口輥道 升降液壓缸 供油的管子，取速度值為 3，則d4=()189。 快退時完成動作時間 t839。=V6/Q6 快退 =。 快退時完成動作時間 t439。對輥式矯直機必須保證工作輥和支承輥的輥面硬度有一個差值。 （ 3） 為了提高矯直效果，矯直機出口處的上（或下輥） 可以單獨調(diào) 整，且在矯直過程也可以進行調(diào)整。新型高效率的管材精整設(shè)備，尤其是管材矯 直 機，是保證管材質(zhì)量的重要關(guān)鍵。為了獲得 很 直的板材和具有正確幾何形狀的鋼材，軋件需要在矯直機上進行矯直。 畢業(yè)設(shè)計說明書 題目 :六輥鋼管矯直機液壓系統(tǒng) 學院：機械工程學院 年級專業(yè)： 09 級液壓 學生姓名：張其春 學號： 202020030075 指導老師：韓賀永 年 月 日 太原科技大學畢業(yè)設(shè)計（論文）任務(wù)書 （由指導教師填寫發(fā)給學生） 學院（直屬系）：機械工程學院 時間： 2020 年 2月 28 日 說明：一式兩份， 一份裝訂入學生畢業(yè)設(shè)計（論文）內(nèi) ，一份交學院（直屬系）。所以矯直機是軋鋼生產(chǎn)中的重要機械設(shè)備，而且也廣泛用于以軋材作坯料的各種車間 (如汽車、 船 舶制造廠等 )。國內(nèi)外對管材矯直機均做了大量的研究工作。 （ 4） 上矯直輥可以橫向傾動，能分別調(diào)整各段支承輥，以改變矯直 輥的撓曲，消除鋼板的單側(cè)或者雙側(cè)邊浪。 二． 明確設(shè)計要求 主機的概況： 要求設(shè)計一套六輥鋼管矯直機液壓系統(tǒng)。=V4/ Q4 快退 =。 ，出口輥道升降液壓 缸所需流量計算 入 .出口輥道升降液壓缸： CD250A80/56150A10/02CGDMA 數(shù)量 4 個 單獨控制 往返速度 100MM/S 快進時： Q7 快進 =A7X v7= smmsmmmm /502400/100804 32 ??? ）（? ≈ 快退時： Q7 快退 =A739。=V8/Q8 快退 = 參數(shù)匯總?cè)缦拢? 名稱 型號 數(shù)量