Tower crane is the most commonly used lifting equipment in construction sites, also known as "tower crane", which is used to hoist building raw materials such as steel bars, wood beams, concrete, steel pipes, etc., and is extended section by section (referred to as "standard section"). Tower crane is an indispensable equipment in construction site.
The function of tower crane tower tip is to bear the upper load from the jib rope and the balance jib rope, and transmit it directly to the tower structure through the rotating tower, turntable, bearing seat and other structural components. The top of jack-up tower has truncated cone column, forward or backward truncated cone column, herringbone frame and diagonal support frame. All top-swing tower cranes need to be equipped with balance weights, whose function is to support the balance weights, so as to form the balance torque required by the design in the opposite direction to the lifting torque. In addition to the counterweight, a lifting mechanism is often installed at its tail. The hoisting mechanism is placed at the end of the balance arm together with the counterweight, which can play the role of partial counterweight, increase the distance between the rope drum and the guide wheel of the tower tip, facilitate the winding of the wire rope and avoid rope disorder. The size of the counterweight is inversely proportional to the length of the balance arm, and the length of the balance arm is proportional to the length of the boom. The balance weight is quite large. Generally, light tower cranes should be at least 3~4t, and heavy tower cranes should be nearly 30t.
Tower crane, also known as tower crane, originated in western Europe. According to records, the first patent for tower crane for construction was issued in 1900. 1905 saw the crane with fixed tower and boom, 1923 made the prototype of modern tower crane, and the first relatively complete modern tower crane appeared in the same year. 1930, Germany has started mass production of tower cranes and used them in buildings. 194 1 year, the German industrial standard DIN8770 on tower cranes was published. According to the standard, the product (tm) of lifting weight (T) and amplitude (M) is used to express the lifting capacity of high-torque tower crane.
China tower crane industry started in 1950s. Compared with the depression of tower crane industry caused by the weak construction industry in Central and Eastern European countries, the tower crane industry in China is in a period of rapid development.
Tower cranes are divided into two categories: upper rotary tower cranes and lower rotary tower cranes. Among them, the former has higher bearing capacity than the latter. In many construction sites, what we see are tower cranes with top-to-top lifting and joint connection. According to whether it can be moved, it can be divided into walking type and fixed type. The tower body of the fixed tower crane cannot rotate, and it is installed on the whole concrete foundation or X-shaped concrete foundation in a strip shape. In housing construction, it is generally fixed.
Basic classification
It can be divided into: 1 according to the luffing mode. Pitch pitch type; 2. The car is pitching.
According to the operation mode, it can be divided into: 1. Jack-up; 2. I didn't mention it myself.
According to the rotation mode, it can be divided into: 1. Movable arm type; 2. Lower rotary type.
In a fixed way, it can be divided into: 1. Track type; 2. Jellyfish posture.
According to the spire structure, it can be divided into: 1. Flat head type; 2. Pointed type.
According to the operation mode, it can be divided into: 1. Mechanical automation; 2. artificial control.
Operating procedure of folding tower crane
1. Before use, check whether all metal structural parts and appearance are in good condition, whether the sound is normal during no-load operation, whether the braking is reliable during heavy-load test, whether the safety limit and protection devices are complete and intact, and whether the actions are sensitive and reliable before use.
2. When operating each controller, it should be operated step by step, and it is forbidden to operate beyond the block. When changing the running direction, the operating handle should be reset to zero, and the motor should stop running and then run in the opposite direction, so as to be stable. It is forbidden to start and stop suddenly.
3. During the operation of the equipment, if any abnormality is found in the machinery, it should be stopped immediately for inspection, and it can only be operated after troubleshooting.
4. Strictly hold relevant certificates. Do not work after drinking. It is forbidden to use travel switch instead of parking operation. It is strictly forbidden to operate illegally and leave the post without authorization or give the machine to others to drive.
5. When loading heavy objects, you should leave the ground for a certain distance before moving on.
6. Adhere to the "Ten Articles" principle. After the operation, cut off the power supply, lock the box and do a good job of mechanical "crossing". The contents of the ten don't hang are as follows:
(1) Inclined crane does not lift.
(2) Overload is not lifted
(3) If the bulk material is too full or loosely bound, it shall not be hoisted.
(4) The edge of the suspended object is not suspended, and there are no protective measures.
(5) People should not hang on the hanger.
(6) The command signal is unknown.
(7) The built-in parts shall not be hung.
(8) the safety device fails to hang.
(9) If the light is dim, it is not clear that the object has not been hoisted.
(10) Strong winds above level 6 are not suspended.