Design and application of steel wire rope supporti

Design and application of steel wire rope supporting device for tower crane

with the rapid development of China's economy, there are more and more high-rise buildings and engineering facilities. With the construction of high-rise and super high-rise building facilities, the requirements for the performance and use of tower cranes for buildings are becoming higher and higher. Especially in large-scale construction projects, several large tower cranes are sometimes used. With other construction machinery, a construction project can only be completed with dozens of construction machinery. In this way, several large tower cranes are sometimes erected on the construction site. Due to the limitation of space location, the working ranges of tower cranes sometimes overlap each other. In order to avoid mutual interference, the lifting heights of each other are different, so that the jibs avoid mutual interference. However, the jib of large horizontal luffing tower crane is generally long, generally more than 50m, and the longest can reach about 75m. Under the action of its own gravity, the lifting wire rope on the jib sags. Due to the relatively long jib and the relatively large diameter of the lifting wire rope of the large tower crane, its own weight is also relatively large. Sometimes the sagging length reaches about 3M, and generally it reaches about 2m

such a large sagging length is easy to interfere with each other during construction, and sometimes with buildings. In order to prevent interference, the lifting height of the tower crane has to be increased, which is sometimes limited by the independent lifting height of the tower crane itself or the attachment position, which is difficult to achieve. Such interference is very dangerous and prone to safety accidents. Therefore, how to solve the problem of large horizontal luffing tower crane in construction is very necessary. This paper introduces the structural principle and application of the lifting wire rope supporting device designed by the author for a large tower crane with a boom length of 74m

1. Working principle and structure of the rope supporting device

1.1 principle

the working principle of the rope supporting device for lifting steel wire rope is shown in Figure 2. When the luffing trolley moves forward, the front trolley pushes the front trolley 3 of the rope supporting device. The front trolley pulls the steel wire rope 11 through the rope supporting device and the rear trolley 9 moves forward together. The lifting steel wire rope on the rope supporting wheel of the rear trolley is lifted by the rear trolley. Similarly, when the luffing trolley moves backward, the rear trolley of the supporting rope will be pushed, and the rear trolley of the supporting rope will pull the front trolley of the supporting rope to move backward, and the lifting wire rope on the supporting rope wheel of the front trolley of the supporting rope will be lifted by the front trolley of the supporting rope. Adjust the distance between the front car and the rear car of the rope to minimize the maximum suspension height of the hoisting wire rope

1.2 structure

the structure of the front and rear rope supporting devices is the same. The rope supporting frame body is welded by profile steel and steel plate. Two of the four rollers roll on the upper surface of the lower chord of the boom, and the elasticity is installed on the frame body in front of and behind the rollers. The company plans to work with Zhejiang Haihai, but there will be relatively less protection in the later stage. A high-grade polylactic acid manufacturer will provide ecoflex ○ R and polylactic acid bumpers to biodegradable product enterprises respectively, A rope roller for supporting economic operation of the industry, which is processed with nylon rod, is installed under the frame body

2. Threading method and adjustment method of rope supporting device

2.1 threading method

place the rope supporting trolley in front of and behind the luffing trolley as shown in Figure 2, lock one end of the wire rope pulled by the rope supporting trolley on the front trolley (a), pass through the boom tip pulley, the pulley block on the boom frame, the boom root pulley, the rear trolley and the luffing trolley, and finally lock the other end of the wire rope on the front trolley (b)

2.2 adjustment method

keep the front car and the rear car half the distance of the boom length, adjust the tightness of the wire rope by adjusting the "a" and "B" wire rope clamps on the front car, and finally fix the rear car with two wire rope clamps at the traction rope D of the rope car. After rope winding, operate the trolley back and forth several times to check whether the system operates normally

in addition, it must be noted that the wire rope pulled by the rope carrier shall not interfere with the luffing wire rope when it passes through the guide wheel of the rope carrier and the luffing trolley. When using the rope trolley, ensure that the elastic bumper is installed on the rope trolley, and it is strictly prohibited to install on the luffing trolley. However, when the rope trolley is not used, the elastic impact block must be installed on the luffing trolley

the lifting wire rope supporting device has achieved good results in the actual use of the large horizontal luffing tower crane of the East China Sea natural gas reserve project, reducing the erection height of the tower crane, saving the construction cost and improving the construction efficiency. The author believes that with the application of large tower cranes in large projects, this problem will attract more and more attention from the construction party, and the rope supporting device will be gradually applied to large tower cranes. At the same time, the author believes that the safety problems caused by preventing the lower part of the lifting wire rope, especially the lens surface from being kept clean and sagging, should be considered in the revision of the corresponding lifting machinery technical standards and safety standards