The most popular multifunctional stepless speed re

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Abstract: This paper introduces a new type of construction elevator, which has the characteristics of stepless speed regulation and steel bar transportation

key words: construction elevator; Stepless speed regulation; Multi function

construction elevators have been widely used as vertical transportation equipment for transporting personnel and bulk materials in general high-rise buildings. However, for some special buildings, such as tall chimneys, piers and other buildings with few materials but high height, the functions of ordinary construction elevators are far from being adapted. This kind of building is characterized by small area, less materials and large height. During the construction process, it is necessary to transport both personnel and inspection. Reinforcement, formwork and construction machines and tools. Therefore, construction enterprises hope to use multi-functional construction elevators to complete all vertical transportation tasks for many years. In this way, the contract signing ceremony can not only meet the requirements of narrow site, but also reduce the investment of other vertical transportation machinery, so as to save investment, facilitate site management, civilized construction, and improve construction efficiency and benefits

according to the needs of the project, the construction mechanization research branch of China Academy of Building Sciences and Langfang Kaibo new technology development company jointly developed a multi-functional stepless speed regulation construction elevator (Figure 1), which has been in Shanxi. It has been applied in the chimney construction of several power plants, such as Tianjin, and achieved good results.

1 characteristics of multi-functional stepless speed regulation elevator

compared with ordinary elevators, the multi-functional stepless speed regulation elevator has its remarkable characteristics in the following aspects

1.1 control system

the control system is the key part of the construction elevator and determines the performance of the whole machine. The control mode of ordinary elevators is realized through contactor control. The speed is single, the impact of starting and braking is large, the structure and mechanism are seriously damaged, the electrical components are easy to be damaged, and the running speed is relatively low, generally 34-38m/min, which affects the construction speed and the benefit of the construction enterprise. If the speed is simply increased, the acceleration will be too large, and the impact on the structure and mechanism will be too large, which will accelerate the wear of the gear rack and brake disc, thus reducing the reliability of the running tensile specimen to meet the tensile test requirements of relevant national and industrial standards for different materials. The control system of this machine is composed of the expert frequency device (VVVF) and programmable logic controller (PLC) of Sandvik material technology: high-performance corrosion solution, which realizes the stepless speed regulation of the starting, acceleration, deceleration and braking process of the construction elevator, reduces the impact of the gear rack during the starting and braking, and improves the stability ③, sample clamping and comfort during the operation of the construction elevator, The service life of the construction elevator is prolonged, and the stepless speed regulation of 0-60m/min is realized, which greatly improves the work efficiency. In the process of use, the operating speeds of each gear can be set according to the working conditions to meet the needs of different operating speeds in the construction of high-rise buildings

the computer programmable controller is used to control, which improves the intelligent degree, reliability and accuracy of the control system, simplifies the hardware equipment, and has extremely high advantages compared with the relay system with high failure rate. The software programming technology of programmable controller is adopted to simplify the operation, prevent misoperation and increase the safety protection function

1.2 transportation system

during the transportation inspection, the ordinary construction elevator places the pusher in the lifting cage. The transportation inspection amount of each lifting cage is only about 0.2m. Not only the transportation inspection amount is small, but also takes up most of the space of the lifting cage. This machine places the hopper at the bottom I of the lifting cage, which not only saves the space of the lifting cage, so that the lifting cage can also transport construction personnel and other items during the inspection, but also increases the capacity of the hopper to 0.6m. When the inspection arrives at the construction layer, it is quickly transported to the pouring place by a trolley, which improves the work efficiency

1.3 transportation and hoisting of reinforcement

the length of reinforcement used in construction is generally 6-9M, which cannot be transported by ordinary elevators. The machine is equipped with a movable top door on the top of the lifting cage, a station cage on the top of the driving frame and the lifting cage, and a special quick locking ferrule is set outside the station cage. When transporting the reinforcement, place the reinforcement at the bottom of the cage through the top door, and lock the middle and upper parts with locking ferrules to prevent accidents caused by the interference between the upper part of the reinforcement and the guide rail frame during transportation

1.4 movable frame and boom system

the boom of ordinary elevator is installed on the top of the cage to complete the disassembly of the standard section. It is removed or fixed during normal work. The suspender of this machine is not only used to dismantle the standard section, but also used to hoist the reinforcement. It is frequently used. Because the reinforcement is long, if the suspender is still placed on the top of the cage, its height must be increased. The machine adds a mobile frame on the top of the guide rail frame, and the suspender is installed on the frame. The frame can rise with the heightening of the guide rail frame. When hoisting the reinforcement, fix the upper part of the reinforcement with a hook, lift the hook or lower the cage to complete the hoisting of the reinforcement. The positioning is accurate and reliable, and the work efficiency is significantly improved

1.5 cable pulley system

when the building is higher than 150m, in order to avoid mutual twisting and scraping of cables during the operation of the cage, reduce the impact on electricity during equipment startup, and extend the service life of the electrical system, the elevator is generally equipped with a cable pulley system. Due to the poor working environment of the construction elevator, especially during the transportation, the inspection often falls between the guide wheel of the pulley and the column pipe of the guide rail frame, forming a broken storage area. If the inspection is not cleaned in time, it is easy to cause the pulley to run up and down smoothly, resulting in the cable being pulled or broken by the lowered cage. The pulley guide wheel of the machine adopts a narrow wheel (Fig. 2), and there is no inspection and storage area between the guide wheel and the column pipe, which greatly reduces the probability of jamming of the pulley

1.6 multi variable resistance system

the attachment distance of ordinary elevators is generally within 3.4m, but for some special-shaped buildings, due to their complex and changeable shapes, the attachment distance is different. For this reason, the machine adopts a plane two-stage retractable attachment system, so that the attachment distance can be adjusted in a wide range between 2.5-7.5m to adapt to the attachment and installation of the elevator in special-shaped buildings. At the same time, the influence of adhesion on thin-walled buildings can be improved by changing the attachment and support distance

2 application examples and Prospect Analysis

the chimney of Jixian Panshan Power Plant undertaken by Tianjin electric power construction company is 250m high and the inner cylinder diameter is 10.68m. The multi-functional stepless speed regulating elevator is installed inside the chimney. The distance to the wall is 4.85M, and the whole process running time is less than 5min, which is nearly half shorter than that of the ordinary elevator; In addition, 1.2m 'reinforcement and a small number of construction personnel can be transported at the same time each time. The comprehensive construction efficiency is greatly improved, making the project completed more than one month ahead of schedule, saving construction costs and being highly praised by users

to sum up, the remarkable feature of the multi-functional stepless speed regulation construction elevator is that it is efficient, safe and multi-purpose. It solves the shortcomings of the ordinary elevator, such as slow speed, single function and large starting and braking impact, improves the performance of the whole machine, prolongs the service life of the whole machine and its parts, improves the construction efficiency and saves the maintenance cost. Therefore, the multi-functional construction elevator has broad prospects for development. It will be more and more widely used in construction fields such as power construction, creating good economic and social benefits. (end)

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