Crane extension and installation device to achieve bidirectional tension control and method for achieving bidirectional tension control crane

A crane extension and installation device to achieve bidirectional tension control comprising an extension device, a plurality of winches, a pulley and a plurality of cables;

• a crane is connected to the extension device in a horizontal direction through a movable joint at one end in a vertical direction, the crane is connected to a crane base through a first joint at the other end in the vertical direction, and the crane base is used to support the crane, a main arm of the crane is installed with a slide rail in the vertical direction, the main arm has an inclination angle to the vertical direction, three second pulleys at different heights of the slide rail are installed in the vertical direction of the slide rail, and the second pulleys can slide vertically along the slide rail, and can be fixed at a certain position of the slide rail, the extension device consists of several cantilever beams connected end-to-end, and a fixed pulley is installed on a lower peripheral surface of the extension device, a front cantilever beam of the extension device has the fixed pulley installed on its lower peripheral surface, and an end face of the front cantilever beam is installed with a vertical lower arm through a second joint, a bottom end of the lower arm has a first pulley fixed by the bottom end;
• an end of a load in a horizontal direction is connected to a first cable of the plurality of cables, and the first cable bypasses the first pulley, the fixed pulley, and the second pulley with a highest vertical position to connect to a third winch of the plurality of winches, and the third winch is fixed on the crane base;
• an other end of the load in the horizontal direction is connected to a second cable of the plurality of cables, and the second cable bypasses the second pulley with a lowest vertical position to connect to a first winch of the plurality of winches, the first winch is fixed on the crane base;
• a middle part of the load in the horizontal direction is connected to a third cable of the plurality of cables, and the third cable bypasses the second pulley in a middle position of the vertical direction to connect to a second winch of the plurality of winches, and the second winch is fixed on the crane base;
• the first winch and the third winch are located at ends of the crane base in the horizontal direction, the second winch is located in a middle position of the crane base in the horizontal direction, the first winch is closer to the extension device in the horizontal direction.