Balance crane with parallel four-bar mechanism

Abstract

The invention relates to a balance crane with a parallel four-bar mechanism. The balance crane comprises a gate seat, a rotary table connected to the gate seat in a pivot mode through a rotary support, a rotary seat fixedly connected to the rotary table and the parallel four-bar mechanism; the parallel four-bar mechanism comprises a main arm, a fetching bar, a pull bar, a balance weight bar, a main oil cylinder and a sub oil cylinder; the main arm is rotatably connected to the rotary seat; the middle of the fetching bar is detachably and rotatably connected to the front end of the main arm bar; the front end of the pull bar is detachably and rotatably connected with one end of the fetching bar, and the pull bar is located over the main arm bar; one end of the balance weight bar is detachably and rotatably connected with the back end of the pull bar, and the other end of the balance weight bar is detachably and rotatably connected with the back end of the main arm bar; one end of the main oil cylinder is rotatably connected to the main arm bar, and the other end of the main oil cylinder is rotatably connected to the rotary seat; one end of the sub oil cylinder is rotatably connected to the balance weight bar, and the other end of the sub oil cylinder is rotatably connected to the main arm bar; the main arm bar, the fetching bar, the pull bar and the balance weight bar form a parallelogram; the telescopic operation speed and strokes of the main oil cylinder and the sub oil cylinder are set and controlled through a PLC.

Description

technical field [0001] The invention relates to a hoisting machine, in particular to a jib type crane. Background technique [0002] The existing four-link gantry crane, if attached figure 1 As shown, its structure is: 1. Four-link boom, one of the links (that is, the upper rotating column) is a fixed structure, and the opposite sides of the four-bar mechanism are not parallel; 3. The wire rope 22 is led out from the hoisting mechanism reel, and then hangs the sling to pick up the object to realize lifting; 4. The balance counterweight is placed at the end of the balance beam and connected to the main boom frame through a small pull rod to balance The counterweight system is relatively independent from the four-bar mechanism, and they are separate systems, but they are connected through a small tie rod to realize the synchronous movement of the two, that is, the balance counterweight system is not on the four-bar mechanism. Its working principle is: the luffing mechanism...

AI Technical Summary

Problems solved by technology

[0003]This type of four-link portal crane has the following disadvantages: 1. The wire rope is a vulnerable part and needs to be replaced regularly; Possibility of breakage; 3. The steel wire rope hangs the sling, and it shakes a lot when picking up the object, especially when turning; 4. When using a grab bucket, the grab is picked up by its own weight. 5. The whole mechanism is complex, divided into four-bar boom system and balance counterweight system, which is difficult to design and manufacture; 6. The maintenance during operation is difficult and expensive; 7. The balance is not really achieved, and when the lifting mechanism is lifted high energy consumption

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