What Is The Auxiliary Hook Of A Large-tonnage Bridge Crane Used For?

What is the auxiliary hook of a large-tonnage bridge crane used for?

What is the auxiliary hook of an overhead crane used for? What is the difference between it and the main hook? What is the function of the auxiliary hook when lifting heavy objects? During my years of working, I often encounter the above questions from customers. Many friends will have doubts: Why are there double hooks on the crane? I have compiled it as follows and given appropriate answers:

The hook bridge crane is the basic type of general bridge crane. Large-tonnage bridge cranes generally have two sets of lifting mechanisms, that is, there are two hooks, respectively, the main hook and the auxiliary hook. This kind of lifting The structure is also called a double-frame crane.

How to choose whether to use the main hook or the auxiliary hook to lift heavy objects?

The main hook is the main hook used. Its characteristics are: large lifting capacity and slow lifting speed. Most of the crane's work is done by the main hook, especially when lifting materials with heavy lifting capacity. After the rated lifting capacity of the auxiliary hook is exceeded, it can only be lifted by the main hook for safety reasons; the auxiliary hook plays an auxiliary role. It can also be used alone to lift heavy objects. The lifting speed is faster than the main hook (because the auxiliary hook is generally single or 2 times), which can improve the lifting efficiency of light goods. However, the lifting capacity is lower than that of the main hook, about 1/5~1/3 of the main hook. Generally, when the lifting weight is relatively light and the speed requirement is relatively high, it is better to use the auxiliary hook.

The rated lifting capacity of the crane is the lifting capacity of the main hook. The total weight of the materials being lifted cannot exceed the maximum lifting capacity of the main hook, and overload lifting is not recommended.

There are four things to note when using the main and auxiliary hooks:

1. Under normal circumstances, the main hook and the auxiliary hook cannot work at the same time to avoid safety accidents. When lifting molten steel or other special operations, the auxiliary hook can be used to assist.

2. The rated lifting capacity of the crane is the lifting capacity of the main hook, and the weight of the objects being lifted cannot exceed the maximum lifting capacity of the main hook.

3. When the main and auxiliary hooks are replaced and when the heights of the two hooks are similar, the sub-combination crane should work alone to avoid collision between the two hooks.

4. In principle, it is not recommended to lift two objects with two hooks for a double-joint crane. The inoperative hook needs to be raised to a height close to the limit position, and no wire rope is allowed to be hung on the hook.

Examples of how the main hook and auxiliary hook are used together:

The double-girder large-tonnage bridge crane requires the cooperation of the main hook and the auxiliary hook to lift molten steel. When lifting, the two hooks lift at the same time and drive the large and small cars to transport the molten steel ladle to the casting position. During casting, both hooks are lowered at the same time. When the pouring ladle is lowered to a suitable height for casting, the auxiliary hook is slowly raised to gradually raise the bottom of the pouring ladle. At the same time, the main hook continues to lower and the position of the trolley is adjusted to ensure that While the pouring ladle is being turned over, make sure that the pouring ladle's spout is always aligned with the gate, and the poured molten steel is accurately injected into the gate. During the pouring process, both the main and auxiliary hooks should be in slow speed. Pour the molten steel to prevent the molten steel from damaging the sand mold.

When the driver operates the main hook and auxiliary hook of the bridge crane, he must strictly abide by the driver's operating procedures to avoid unnecessary accidents, endangering equipment and personal safety, and affecting enterprise production.