四层杂物电梯 PLC
控制 外文翻译
Abstract
microelectronic technology's development, elevator's dragging way and the control
method has had the very big change, the exchange velocity modulation is the current
elevator dragging main development direction. At present the lift control system
mainly has three control modes: Following electric circuit control system (“early
installment elevator many black-white control system), PLC control system,
microcomputer control system. Because the black-white control system the failure
rate is high, the reliability is bad, control mode not nimble as well as consumed power
big and so on shortcomings, at present has been eliminated gradually. Although the
microcomputer control system has the strong function in the intelligent control aspect,
but also has the interference rejection to be bad, the system design is complex,
generally the servicemen master flaws with difficulty and so on its service technology.
But PLC control system, because moves the reliability to be high, the use service is
convenient, anti-jamming, the design and the debugging cycle is short and so on
merits, time is taken seriously the people and so on merits, have become present use
most control modes in the lift control system, at present also widely use in the
tradition black-white control system's technological transformations.
The origin and development of the elevator
Elevator in the Chinese dictionary explanation: building electricity powered lift,
instead of walking up and down the stairs.
When it comes to lift from the origin of the 2600 BC Egyptians built in Pyramid
using the original lifting system to start, but this kind of crane energy are
human. By 1203, two French monastery installed a crane, the difference is
just the machine is the use of donkey as power, load by around a large drum
rope for hoisting. This method has been used to modern until Watt invented
the steam engine, in about1800, mine owners can use the crane to mine in
coal transportation.
For hundreds of years, people made various types of elevators, they all have
a common defect: as long as the lifting rope snaps, lifting ladder he rapidly hit
bottom layer. 1854 Otis design a brake: in the lift platform mounted on top of a
truck with a spring and a brake lever and Lift Wells Road on both sides of the
guide rail is connected with the lifting rope, wagon springs, this is only the
lifting platform weight is sufficient to pull spring, avoid contact with the brake
lever. If the rope breaks, truck spring will pull the ends of vertical weakened,
and the brake lever occlusal, can be firmly fixed without in situ platform
continues to fall. " Safe lifting ladder" invention success! For a time, Otis has
become the center of attention. The first lift not Otis invented, but he was the