Fault And Treatment Of The Mechanical Parts Of The Leg

- Jun 08, 2017-

(1) Repair of frog-type leg abrasion

The most vulnerable leg of frog-type legs is the guide slot on the movable leg 8, if the wear of the surface of its work reaches 1.5mm, it should be replaced, otherwise, in the retractable leg, movable leg and fixed leg will produce impact phenomenon, prone to accidents. At this point the working surface of the guide groove should be welded, as shown in Fig. 2.

Remove the movable leg first, measure the dimension of the Guide groove, determine the thickness of the weld. Repair welding, shown with screws 5 and nut 7 will be rectangular copper cushion 4 installed, the copper tube 3 sets in the Screw 5, the completion of welding a paragraph, and then move to repair the next paragraph until the end of the welding. For convenience, the electrode can also be moderately bent. But pay attention to the location of the solder fill must be in Fig. 1 Guide groove of the lower surface. This does not affect the stroke of the piston rod of the hydraulic cylinder and the relative angle between the supporting leg and the movable leg when supporting the leg. After welding, use a standard shaft (shaft diameter equal to the outer diameter of the rolling sleeve) to make the Datum, repair the shape, and should note that both sides of the groove must be repaired simultaneously with the same root axis.

If the outer diameter of the rolling sleeve 9 is more than 1mm, it should be replaced, otherwise, it is easy to be crushed in the work, so that the force condition of the leg is changed, and the hidden danger is buried.

The frog-leg repair also has a focus, which is shown in Figure 1 of the Screw 4, in a frog-style leg, a total of 3, the 3 screws due to radial force is very easy to be cut (turn around). Shear after the screws are not good to the outside twist, so a lot of 5 are welded to die, so, one is not good-looking, the other is the demolition must be gas welding cut, inconvenient. After a long period of observation, we recommend the following: the screws used in the axial positioning of the pins should be checked frequently. Preferably not more than two years to replace it. Here is a simple method of checking the screws, which are compared with a new screw with the same pitch. Two screws close together, look at the gap, if the gap is larger, two screws can not stick together, indicating that the old screws have been deformed, has been tired, should be replaced, but also with the same size taps to make comparisons.

(2) repair of upper and lower wear of H-type outrigger horizontal beam

In the case of crane overloading, the lifting weight is at the rear of the vehicle, higher than the leg. At this time the person in the car's rear looking at the leg, if the case appears as shown in Figure 3, that is, the figure A, b two point of the horizontal distance is greater than the body 2 above the thickness of the metal plate, or leg expansion if there is crawling phenomenon, it is necessary to remove the legs to detect, if the board has deep groove or serious damage, it is necessary to test the tiger to replace the new leg, or to wear parts of welding. The cost of repairing leg is lower.