Published on July 20, 2014
The crane hook the troubleshooting process: The crane hook the troubleshooting process Crawler crane hook slip phenomenon occurs main hook troubleshooting process : Crawler crane hook slip phenomenon occurs main hook troubleshooting process Troubleshooting ( 1 ) Analysis The main hook jib crane winch brake band appeared to slip, slide the hook when the main hook , maintenance personnel to adjust the brake band adjustment bolt 6 , with two brake tension , then the main hook " hook slip phenomenon" disappear. But after the brake with two tensioning , brake and brake drum with 2 1 can not completely out , but with the brake drum brake with two friction generated an abnormal sound . Repeatedly adjust the brake band from the spring 8 , with 2 still can not guarantee that the brake is fully disengaged. In desperation, turn the adjusting bolt to make minor adjustments to relax 6 braking direction , relying on friction and brake drum brake with 2 1 of the brake . After a period of time , brake drums and brake with a two worn brake with 2 slipping again , leading to the main hook hook slip phenomenon again. The field carefully observed during brake release , within the framework of 14 under the action of lifting the brake cylinder 9 has a brake spring 13 is fully compressed , the free fall hook brake push rod 15 rod end and the free fall hook system the top end surface of the movable cylinder 10 together with the piston , thus causing the brake arm 5 can not be rotated clockwise under the action of the return spring 8 , causing the brake band can not open , the brake is not fully released . ( 2 ) a process of elimination First, the free-fall hook brake push rod 15 removed ( temporarily using free-fall hook function ) , the individual parts brakes refitted . Second, adjust the adjusting bolt 6 , until the main hook single rope adjusted to the maximum braking force with two non-skid . Again, adjust the brake band from the spring 8 , 100 ton mobile crane until the brake band gap 2 with brake drum 1 is uniformly repeated in the main hook line pull biggest test since hook, off the hook , stop, make sure that it does not appear to slip the hook and manufacturing belts and brake drum friction phenomenon . Then , the brake released state in free fall hook measuring cylinder 10 is connected to the piston face from the center of the pin 16 according to this distance minus 5mm margin, the free fall ends hook chopped brake push rod 15 . Finally, the free-fall hook safety brake push rod 15 back into place , test again , brake , release the brake , free-fall hook functions are normal. Crane hook down automatically causes and troubleshooting methods : Crane hook down automatically causes and troubleshooting methods Examination found that as long as one to start the engine , hook it began to decline , and the valve at the cab to hear " dth , dth ," the oil flow sound. After the engine flameout , this phenomenon disappears. Analysts believe that after the engine flameout hook longer decline, indicating winch brake , no problem. After the aircraft hydraulic control system diagram analysis concluded that only the control handle oil into action the pilot control valve to open the winch brake . Since devolution does not need to hook electrical control , jib cranes so you can also exclude faulty electrical aspects of possible problems should be out in the hydraulic system. By analyzing the hydraulic system diagram , determine the point of failure should be between the cab winch control valve handle . First of dismantling the cab control lever pilot control circuit, observe the oil flow situation . When the handle is in the neutral position when there is no control of the tubing hanger downward flow of oil , which illustrate the handle control no problem. Then dismantling the hoist valve, found in the main spool a self-locking spring break , causing the hook because of the self-locking down automatically lapse . The winding machine and the control valve has the same structure as the control valve 3 groups , one of which is an alternate valve. The spare winch control valve which has a valve with the same parts, and did not install any tubing. Since there was no accessories, will spare valve spring to remove a valve attached to the winch , hook again automatically drop test machine fault disappears . Although the test machine repair the crane properly, but then the phenomenon occurs automatically turn off the engine while shaking the hook when decentralization , and you can not start the engine automatically turn off. After the power take off , starts normally, after turning on the power take off , can not start . Hydraulic diagram analysis found that , although not with any spare valve connecting tubing , but the oil will flow through the pump output spare valve. If the alternate valve spool action, the oil flow will impact the winch control valve , causing the hook shaking. And because there is no spool does not automatically return spring , materials lifting equipment leading to the load increases, the engine power is insufficient , or even fail to start. After refitted spare valve springs , fault disappears. The troubleshooting procedure shows an alternate valve spring is also useful , can not be easily removed.