Hydraulic obstacle surmounting device of ship crane

When a crane meets an obstacle, an operator is generally required to actively stop rotation in time and perform variable amplitude rotation to detour the obstacle, and the operation always causes collision accidents due to momentary neglect of the operator. The invention relates to a hydraulic obstacle detouring device. A combined limiting valve block is connected in series between a rotary limiting device and a variable amplitude limiting device to associate rotary limit and variable amplitude limit, so that the crane can be automatically limited to rotate when closing to the obstacle duringrotation; and when a hoisting arm is in variable amplitude and lifted to a certain height, the crane can continuously rotate to detour the obstacle, so collision accidents in the operating process ofthe crane are effectively prevented, the labor intensity of the operator is reduced, and the operating safety of the crane is improved. Meanwhile, the device has the advantages of simple structure, low cost, reliable operation