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Tower crane, referred to as "tower crane", also known as "tower crane", is a kind of lifting equipment in construction.
Tower crane originated in Europe. The first original tower crane appeared in 1912-1914. In 1923, the prototype of the first modern tower crane was made. In 1930, Germany began mass production of tower crane and used it in construction.
China produced its own tower crane in the 1950 s. In 1954, my country's first TQ2-6-type tower crane was trial-produced by the then Fushun Heavy Machinery Factory, and later produced in Shanghai Construction Machinery Factory and Harbin Construction Machinery Factory. In 1984, the Machinery Bureau of the Ministry of Construction introduced four types of tower crane materials and technical training, including Botan GTMR360B, TOPKITFO/23B, FO/23B and H3/36B, at the price of 3.5 million yuan, which were produced by Beijing Construction Machinery Factory, Shen Jiangong and Sichuan Construction Machinery Factory. Due to the reasonable introduction of the object, fully prepared, tower crane production in the country quickly launched, for the national construction has made an important contribution. The introduction of tower crane technology in 1984 will leave an important chapter in the history of the development of China's tower crane industry.
At the beginning of the 21st century, China's economy has ushered in a new round of rapid growth, and the real estate and construction industries have become new engines of economic development. Driven by these two industries, China's tower crane industry has seen a rare development opportunity. A group of companies have risen rapidly under the impetus of demand, not only winning the domestic market, but also establishing a brand overseas. Yongmao Construction Machinery's flat-head tower crane enjoys a high reputation at home and abroad; the Chuanjian tower crane marked by "SCM" is praised by users as "China's first tower"; the signing of Zoomlion's D5200-240 tower crane project not only rewrites the history of "the world's largest tower crane", but also becomes a milestone in the development of global tower crane technology.
It is undeniable that with the rapid rise of house prices, the development of China's real estate industry has aroused widespread concern. Since the beginning of 2010, the real estate industry has experienced a series of strict regulation and control, the whole market has become cautious, and the wait-and-see mood has been rising. People in the industry should still remember clearly that in the fourth quarter of 2008, with the onset of the financial crisis, the real estate industry experienced a round of rapid and six-month adjustment, many construction projects temporarily stagnated, a large number of tower cranes stood quietly on the construction site, and many small tower crane enterprises and leasing companies were hit hard. A rotating crane mounted on the upper part of a towering tower. The operating space is large, mainly used for the vertical and horizontal transportation of materials in housing construction and the installation of building components. It is composed of three parts: metal structure, working mechanism and electrical system. The metal structure includes the tower body, the boom and the base. The working mechanism has four parts: lifting, luffing, rotating and walking. The electrical system includes motors, controllers, power distribution cabinets, connection lines, signals and lighting devices.
　Tower cranes are divided into two types: upper rotary type and lower rotary type
The upper rotating tower crane is divided into four types: fixed type, attached type and inner climbing type. Its basic feature is that the tower does not rotate. The boom and balance arm above the slewing bearing can make full rotation around the center line of the tower body through the slewing mechanism and slewing bearing. Running tower crane, the whole crane can run along the track, and the working space is large. If the base is fixed on the track, or the tower body is directly fixed on the special basis without the base, it becomes a fixed tower crane, and its boom is long, which can expand the construction work area. In order to reduce the bending moment of the tower body, the fixed tower crane is connected to the building with an attachment rod at regular intervals on the tower body, which is an attached tower crane (Figure 1 [upper rotating attached tower crane]). In order to make the crane can be increased with the building construction layer and the corresponding increase, the tower body self-lifting device can be used. The self-lifting device of the tower body often adopts the jacking hydraulic cylinder, and the piston rod of the hydraulic cylinder is supported on the tower body through the beam. The slewing part of the upper pushing crane, the outer frame and the tower section to be added previously hoisted on the platform are lifted upward to a height of the tower section to be added, and then stop, and support the outer frame on the tower body. At this time, the high-pressure oil returns to the oil tank, the piston rod retracts, pushes the tower section to be added to the center line of the tower body and connects it with the tower body, and supports the piston rod on the newly added tower section to shorten the hydraulic cylinder, make the rotary part, outer frame, etc. fall to the new tower section, and connect with it, the tower body is increased by one section height. The building can also be used instead of the lower tower body, the outer frame and the tower body are supported on the special pedal on the inner wall of the elevator shaft in turn, and the hydraulic cylinder is used to make the crane climb along the elevator shaft, which is called the inner climbing tower crane. Although the internal climbing type saves part of the tower body, it has specific requirements for the building. After the construction is completed, the demolition work is more difficult.
The slewing bearing of the lower rotating tower crane is installed between the base and the turntable. In addition to the walking mechanism, other working mechanisms are arranged on the turntable, and the center of gravity of the whole machine is low. The above parts of the slewing support, such as the turntable, the tower body and the boom (Figure 2 [lower rotating tower crane]), rotate together. Because the tower body rotates and cannot be attached to the building, the height of the tower body is lower than that of the upper rotating type. This kind of tower crane can be disassembled and transferred as a whole, is light and flexible, and is widely used.
When the crane is dismantled and transferred as a whole, the luffing mechanism is started, the tower body connecting arm is placed on the car, the balance weight is removed, the luffing rope is tightened, the tail of the base is tilted, a tire shaft is pushed into, and then the base is supported On the tire shaft, and the tower body and the base are firmly connected with the connecting rod to tow the transfer.
Larger lower rotating tower cranes also often use the tower body self-lifting method, but due to the inability to attach, the self-lifting height is limited. In addition, the lower rotating tower crane, in addition to the rail type, there are crawler type and tire type with crawler chassis and tire chassis as walking devices.
Equipment characteristics and safety devices The boom form of tower crane is divided into horizontal type and pressure bar type. Figure 1 [Upper Rotating Attached Tower Crane] shows that the boom of the crane is horizontal. The load trolley runs along the horizontal boom to change the amplitude, and the amplitude movement is balanced, but the weight of the boom is large. Figure 2 [Lower Rotating Tower Crane]) shows that the boom of the crane is of pressure bar type, and the luffing mechanism traction arm is tilted and luffing. The luffing movement is not as stable as that of the horizontal type, but its self-weight is smaller.
The lifting weight of a tower crane varies with amplitude. The product of lifting weight and amplitude is called load moment, which is the main technical parameter of this crane. The lifting height of the tower crane is large, the inertia mass of rotation and walking is large, so it needs to have good speed regulation performance, especially the lifting mechanism requires light load fast, heavy load slow speed, installation in place micro-motion. Generally in addition to the use of resistance speed regulation, but also often use eddy current brake, frequency modulation, pole change, silicon controlled and mechanical and electrical combination of speed regulation.
In order to ensure safety, tower cranes have good safety devices, such as lifting weight, amplitude, height and load torque limiting devices, as well as travel limit switches, tower top signal lights, wind meters, windproof rails, ladder guards, and walkway guardrails. The driver's cab requires comfort, convenient operation, good vision and perfect communication equipment.

Shandong Huaxia Group is located in the most suitable city for human habitation and entrepreneurship-Weihai, ShandongIt was built in 1985. The business scope covers tower crane, pharmaceutical industry, skills education, overseas labor service, driver training, hotel service, tourism and other fields.

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