Development trend of internal climbing tower crane

Development trend of Japanese internal climbing tower crane

Guide: Abstract: This paper expounds the development history of Japanese internal climbing tower crane, and introduces the main development trend of internal climbing tower crane that day, which is lightweight, intelligent, improving safety and comfort, adopting advanced speed regulating devices and developing new driving devices. Proposed to be based on China's national conditions, based on Innovative Development

Abstract: This paper expounds the development history of internal climbing tower cranes in Japan, and introduces the main development trends of internal climbing tower cranes that day, which are lightweight, intelligent, improving safety and comfort, adopting advanced speed regulating devices and developing new driving devices. It is suggested that the domestic internal climbing tower crane should be innovated and developed based on China's national conditions

1. The development history of Japan's internal climbing tower crane

in 1953, the first horizontal self elevating tower crane (20t/m level) was introduced into West Germany by Japan Shimizu Construction Association. In 1961, Japan developed a domestic 20t/m level tower crane. Due to the high density of urban buildings in Japan, the middle arm of the horizontal tower crane crosses the block, which is easy to collide with similar buildings and high-voltage lines, and the lifting materials are easy to endanger the safety of pedestrians, Therefore, according to the national conditions of Japan, the undulating tower crane with small boom span and little danger to nearby buildings, high-voltage lines and pedestrians is adopted as the common model. In 1962, 45t/m and 120t/m ups and downs tower cranes were developed, and in 1964, 180t/m ups and downs tower cranes were developed. 19 adjust the lower jaw to an appropriate height. In 66, the first high-rise building in Japan, "Xiaguang building", was built by using the floor jacking method, and the internal climbing self elevating tower crane (200t/m class) was developed accordingly. Since then, the internal climbing self elevating tower crane (boom undulating) has become a representative model of tower cranes in Japan. In 1971, 80t/m and 400t/m internal climbing tower cranes for small and medium-sized building construction and high-rise building construction were developed. In 1987, 900t/m internal climbing tower cranes were developed. In 1990, the world's largest 1500t/m internal climbing tower cranes were developed. In the future, we are also preparing to develop super large internal climbing self elevating tower cranes to serve the construction of super large high-rise buildings (800 ~ 1200m high). Nowadays, in big cities such as Tokyo and Kobe, where the repeatability is low, the internal climbing self elevating tower cranes painted with red and white undulating booms stand on urban construction sites, becoming a beautiful scenic spot

2. The development trend of internal climbing tower crane in Japan

2.1 the main type of internal climbing tower crane

the practice in Japan shows that compared with the attached Jack up tower crane, the internal climbing jack up tower crane has the following advantages:

(1) the effective construction capacity is large, and the internal climbing tower crane is installed inside the building (elevator shaft or stairwell and other special bays). The construction surface is round, and the effective operation capacity is more than 80%. The attached tower crane is installed on one side of the building, and the construction surface is semicircular. Therefore, the small type of internal climbing tower crane can be used to replace the large type. By using a series of resources from whisky production by-products to seaweed as an alternative to the selected type of attached tower crane, the number and number of tower cranes can be reduced

(2) low production cost. The length of the standard section of the tower body is less than 32m, and there is no need to increase the standard section of the tower body with the rise of the floor. Therefore, the whole tower crane consumes less steel, and the total production cost (selling price) is low, which is 20% - 30% lower than the attached tower crane with the same construction capacity

(3) the use cost is low. The attached tower crane needs to build the tower crane foundation and wall embedded parts. The effective construction capacity is small, and the corresponding hoisting volume is also small. The internal climbing tower crane is installed on the special bay structure inside the building, and there is no need to build the tower crane foundation and erect horizontal support components. And the effective construction capacity is large. The lifting times per hour are 20% - 30% more than that of the attached tower crane. The lifting volume of the corresponding working shift is more than 30% higher than that of the attached tower crane with the same construction height. Therefore, the total use cost is lower than that of the attached tower crane with the same construction capacity

(4) good safety as mentioned above, the safety of undulating jib operation in narrow construction sites is better than that of horizontal jib operation. In Japan, the internal climbing self elevating tower crane adopts the undulating jib. In addition, because the tower body of the internal climbing self elevating tower crane is not high, and the tower crane base and some tower sections are located in the internal space of the building, the whole tower crane has small wind area, strong wind resistance (especially strong winds and typhoons), strong wind resistance (especially strong winds and typhoons), strong anti-seismic ability, and strong anti-seismic ability. For Japan, which has many typhoons and earthquakes, this advantage is very prominent

(5) because there are few tower sections and no horizontal support rods and other accessories, the floor area of the tower crane component material warehouse is small, and the tower body does not occupy land inside the building, so it can adapt to the construction of narrow construction sites

however, the base of the internal climbing tower crane is located on the body of the building, where the body needs to be reinforced, which is its deficiency

according to the national conditions of Japan and the characteristics of the internal climbing tower crane, Japan has selected the internal climbing tower crane with undulating jib as the main type of Japanese tower crane. In order to meet the construction needs of different levels of buildings, Japan has developed a series of internal climbing tower cranes. The main models are: 80t m, 150t m, 400t m, 450t m, 500t m, 600t m, 900t m, 1500t m, etc. In addition, a steel column tower crane with steel column as the tower body is also developed, which can be used in the construction of steel structure building, simplifying the structure of tower crane and adding a new type of internal climbing tower crane

2.2 lightweight

reducing the dead weight of the internal climbing tower crane can not only save the manufacturing materials, but also reduce the cost of strengthening the supporting body of the tower crane. Its lightweight method is:

(1) the jib and tower section of the tower crane are made of high-strength steel (yield strength 500MPa)

(2) adopt high-strength steel wire braided (lifting weight) steel wire rope (small diameter steel wire rope), so as to reduce the weight of steel wire rope and drum size, and reduce the mass and volume of the whole machine

2.3 high speed

in hoisting, especially in high lift hoisting, the hoisting speed of the tower crane is one of the important factors affecting the construction efficiency (the other important factor is the hoisting weight). Now the highest hoisting speed of the tower crane with high lift (above 250m) in Japan is 121 ~ 160m/min, However, the faster the speed is, the better. High speed is also restricted by the corresponding increase of motor capacity and the complexity of speed control device, which is very important for high speed. Weighing the advantages and disadvantages, the manufacturer believes that 200 ~ 300m/min is suitable for high speed. At the same time, in order to make the hoisted objects accurately in place, it is also required to locate at a low speed (0.25 ~ 0.4m/s) while at a high speed