1. Support Leg Type
The legs of the truck crane can be divided into two types, manual and hydraulically operated. At present, manual manipulation of the leg has been rare, most of the car cranes are using hydraulic support legs. Hydraulic support legs can be divided into the following types.
(1) Frog-type legs
This leg of the movable leg hinged on the fixed leg, the expansion of the action by the hydraulic cylinder, characterized by simple structure, light weight, but the leg span is not small, only applicable to the smaller tonnage of the crane.
(2) H-shaped leg
This kind of leg has two cylinders. Active leg stretched out, the work of the vertical leg support, shaped like H and named. The characteristic is that the leg span is bigger, the adaptability to the site is good, and it has been widely used.
(3) X-type leg
This leg works with an X-shaped leg, from the ground clearance small, in the process of supporting the foot of the horizontal displacement occurs, when it is small amplitude, the space of the weight movement is larger than the H-type leg, so it is often mixed with H-type legs, forming the front h, after the type of x.
(4) Radial leg
The rotary center of the turntable is centered, radiating outward from the frame's basin-shaped frame and extending 4 legs. The characteristic is the stability is good, in the lifting operation, the entire load does not pass through the frame but directly acts on the leg, back this, may reduce the frame weight and reduces the machine center of gravity height, protects the chassis not to be damaged. It is mainly applied to some oversize cranes.
(5) Swinging leg
This leg in the lifting operation, the leg under the action of the hydraulic cylinder can swing to the vertical axis of the frame with the position on the side, not working state, can be fixed parallel to the sides of the frame. Characterized by light weight, but due to the size of the space limit, the leg can not be too long, so the lateral support of the smaller distance.
The role of the leg is:
Under the condition of not increasing the width of the crane, the crane is provided with a larger support span, which can improve the hoisting characteristics without reducing the maneuverability of the crane. The failure of the leg has two kinds of mechanical parts and hydraulic system.