【導(dǎo)讀】的說，提升機械是用作沿井筒提升或下放礦物人員和設(shè)備的一種機械。這些說法都從一個側(cè)面或一定程度上說明了提升機械的功能和特性。這些說法并沒有給出提升機械以嚴(yán)格的定義。于體上機械，交帶輸送機也可以作為聯(lián)系井上與井下之間的搬運工具。動機），控制、保護監(jiān)視及信號裝置等。根據(jù)提升機卷筒（又稱絞筒、滾筒或。它有單圓柱卷筒和雙圓柱卷筒兩種。圓柱圓錐形提升機也是纏繞提升機的一。2）摩擦輪提升機：其特點是靠摩擦輪與鋼絲繩之間的摩擦力傳動。近年來多采用多繩摩擦輪提升機。目前礦井提升機正向體積小、重量輕和自動化方向發(fā)展，以適應(yīng)。備，加強設(shè)備維護，才能確保提升機高效率和安全可靠的工作。4型多繩摩擦式礦井提升機的結(jié)構(gòu)以及。它靠提升鋼絲繩與主導(dǎo)輪的摩擦傳動動力，以實現(xiàn)提升機的正常工作要求。轉(zhuǎn)安全可靠性，會造成礦井生產(chǎn)停頓，甚至不堪設(shè)想的后果。利于保護機械設(shè)備，使其免予過載。

　　

【正文】 格式填入需要顯示的信息及設(shè)定需監(jiān)測的變量。該顯示器最多可顯示 80 條信息，每條信息最多可包括 4 個變量。全部組態(tài)完成確認(rèn)后 Wizard 自動生成一個包括 TD200 參數(shù)和信息的數(shù)據(jù)塊，可以打開“數(shù)據(jù)塊編輯器”來瀏覽 或修改該數(shù)據(jù)塊。熟練的編程者也可不使用 Wizard，直接在“數(shù)據(jù)塊編輯器”中按指定格式對 TD200 編程。 5 結(jié)束語 該控制系統(tǒng)充分發(fā)揮了 PLC 可靠、靈活的優(yōu)勢和 TD200 友好的人機界面功能。實踐證明，系統(tǒng)具有較強的抗干擾能力，操作簡單方便，適合在惡劣的施工現(xiàn)場應(yīng)用，具有一定的推廣價值。 37 錄 2 外文文獻 Control Devices and PLC 1, Types of Controls Devices Several types of control devices are used industry to satisfy the following control needs: Mechanical Control Pneumatic Control Electromechanical Control Electronic Control Computer Control Programmable Control Mechanical control includes cams and governors. Although they have been used for the control of very plex machines, to bi cost effectively, today they are used for simple and fixedcycle task control. Some automated machines, such as screw machines, still use cambased control. Mechanical control is difficult to manufacture and is subject to wear. Pneumatic control is still very popular for certain applications. It uses pressed air, valves, and switches to construct simple control logic, but is relatively sloe. Because standard ponents are used to construct the logic, it is easier to build than a mechanical control. Pneumatic control parts are subject to wear. As does a mechanical control, an electromechanical control uses switches, relays, timers, counters, and so on, o construct logic. Because electric current is used, it is faster and more flexible. The controllers using electromechanical control, except that the moving mechanical ponents in an electromechanical control device are replaced by electronic switches, which works faster and is more reliable. Computer control is the most versatile control system. The logic of the control is programmed into the puter memory using software. It not only can be for machine and manufacturing system control, but also for data 38 munication, Very plex control strategies with extensive putations can be programmed. The first is the interface with the outside world. Internally, the puter uses a low voltage (5 to 12 volts) and a low current (several milliamps). Machine requires much higher voltages (24,110 or220 voltages) and currents (measured in amps). The interface not only has to convert the voltage difference, but also must filter out the electric noise usually found in the shop. The interface thus must be custombuilt for each application. 2, Relay Device Components A relay device is the main ponents of PLC and consists of a front display panel with switches, relays, timers, and counters. Switches A switch is a device that either opens a circuit. Although there are numerous types and styles of switches, they can be classified into the following categories (): LockingNormally ClosedMultiple PoleNonLockingNormally OpenedMultiple Throw Types of switches ● Locking and no locking ● Normally opened and normally closed ● Single throw and multiple throw ● Single pole and multiple pole 39 Typical switches used in the control circuit include: ● Selector switches ● Pushbutton switches ● Photoelectric switches ● Limit switches ● Proximity switches ● Level switches ● Thumbwheel switches ● Slide switches Relay A switch operation is activated by an electromag is called a relay (). The contact and zymology for relays is usually the same as for switches. A small current passes through the mag causing the pole to switch. Usually, the mag is rated between 3to100 volts and a few hundred milliamps. Therefore, it is operated at very low power (current and voltage). A circuit carrying a much heavier rating can be switched using a relay。 however, the two circuits are totally separated. S1S2 S3R1b)TIMERMotorR25 When a relay operates, the contacts dot all open or lose instantaneously. There may be a delay of several milliseconds between the operations of two contacts of the same relay. In the design of a relay circuit, this delay must always 40 be taken into account. Based on the discussion, on can see that a relay is really a magoperated contact switch. The contact switch inside a relay also can be classified by the number of poles and throws. Although most relays are single throw, it is very mon to have multiplepole relay. An Example of Relay Logic For a control process, it is desired to have the process start (by turning on a motor) 5s after a part touch a limit switch. The process is terminated automatically when the finished part touches a second limit switch. An emergency switch stops the process any time when it is pushed. The circuit design for the process control is shown in . In the diagram, LS1 is the first limit switch. It is a normally open type. PB1is a pushbutton switches。 it is normally closed. LS2 is the second limit switch。 it is normally closed. R1 is a doublepole contact. R2 is a relay connected to a motor. S1S2 S3R1b)TIMERMotorR25 41 S1S2 S3R1TIMERMotorR25b) An example of relay logic a) Ladder diagram b) Wiring diagram 3, PLC In order to use the advantages of all those controllers and eliminate the difficulties, the programmable logic controllers were invented, A PLC was a replacement for relay devices. They are programmed using a ladder diagram, which is standard electric wiring diagram. As PLC’s bee more flexible, highlevel as well as lowlevel languages are available to PLC programmers. PLC’s have the flexibility of puters as well as a standard and easy interface with processes and other devices. They are widely accepted in industry for controlling from a single device to a plex manufacturing facility. Programmable logic controllers (PLC’s) were first introduced in 1968 as a substitute for hardwired relay panels. The original int