Truck crane legs, can be divided into manual and hydraulic control of the two categories.Mounting structure At present, the manual control of the legs have been rare, the vast majority of truck cranes are using hydraulic legs. Hydraulic legs can be divided into the following types.
The leg of the activities of the legs articulated in the fixed leg, Mounting structure the expansion of the action by the hydraulic cylinder to complete, is characterized by simple structure, light weight, but the span is not large, only for small tonnage of the crane.
This leg has two hydraulic cylinders. Activities out of the leg, Mounting structure the work of the vertical leg stays, shaped like H named. Is characterized by large leg span, good adaptability to the site, has been widely used.
This kind of leg work, the leg was X-shaped, from the ground clearance is small, in the process of landing on the ground level of the occurrence of horizontal displacement, when it is small, Mounting structure the weight of the activities of space than the H-type legs to large, So often mixed with the use of H-shaped legs, the formation of the former H, after the X type.
To the turntable of the center of rotation as the center, Mounting structure from the frame of the basin-shaped downwardly radially outward out of the four legs. Features are good stability, in the lifting operations, the entire load without the frame but directly on the legs, back to this, can reduce the weight of the frame and reduce the height of the machine center of gravity to protect the chassis from damage. Mounting structure Mainly used in some large cranes.
This leg in the lifting operation, the legs in the role of the hydraulic cylinder can swing to the vertical axis of the frame perpendicular to the position; non-working state, can be fixed in parallel to the sides of the frame. Is characterized by light weight, but due to the size of the space constraints, Mounting structure the legs can not be too long, so the distance between the smaller support.
The effect of the legs is to provide a larger support span for the crane without increasing the width of the crane, thereby increasing its lifting characteristics without reducing the maneuverability of the truck crane. Mounting structure The failure of the leg has two parts: mechanical parts and hydraulic system.
Frog-type legs are the most vulnerable wear points on the activities of the guide groove 8, if the working surface of the wear amount of 1.5mm, it should be replaced; otherwise, Mounting structure in the retractable legs, the activities of the legs and fixed support Legs will produce an impact phenomenon, easily lead to accidents.
First remove the activities of the legs, measuring the size of the guide groove to determine the thickness of welding. In the case of welding, the screw 5 and the nut 7 are used to install the rectangular copper pad 4, and the copper tube 3 is set on the screw 5, and the welding section is finished, Mounting structure and then the welding section is moved until the welding is finished. For convenience, the electrode can also be bent. But pay attention to the location of welding must be in Figure 1 guide groove on the lower surface. This does not affect the stroke of the hydraulic cylinder piston rod and the relative angle between the fixed leg and the movable leg when the leg is loaded. After welding, Mounting structure with a standard axis (shaft diameter is equal to the outer diameter of the rolling sleeve) to do the benchmark, to repair, and should pay attention to both sides of the slot with the same axis at the same time repair.
There is also a focus on the maintenance of the frog leg, Mounting structure which is the screw 4 shown in Figure 1, which has a total of 3 on a frog leg, which is easily cut and turned off by the radial force. Cut off the screw is not good to the outside, so a lot of baffle 5 were welded to death, so that one does not look good, the second is to be used when the gas welding and cutting, inconvenient. After a long period of observation, we recommend that the screws used for axial positioning of the pins in such a way should always be checked. Mounting structure Preferably not more than two years to replace once. Here is a simple inspection method, that is, the screw unloading, with a new screw with the same pitch for comparison, the two screws together, see the gap between the thread, Mounting structure if the gap is large, the two screws do not Together, that the old screw has been deformed, Mounting structure has been tired, should be replaced, you can also use the same size of the tap for comparison.