Troubleshooting of common faults of shikawashima c

2022-08-16
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Troubleshooting of common faults of Ishikawa crane

Ishikawa crane mainly completes various actions by hydraulic components, control solenoid valves, etc. Since the 13 Ishikawa CCH280WE cranes of our company were put into use in 1995, they are mainly engaged in cargo hoisting and coal unloading from trains after installing grab. The troubleshooting of common faults is as follows

1. Oil leakage from the oil seal of the central swivel

the main reason for oil leakage from the oil seal of the central swivel is that the fixing bolt of the pressing plate of the central swivel is easy to loosen, which leads to the open welding of the welding part, accelerating the damage of the oil seal and air seal

it was originally solved by adding caps and spot welding, but the effect was not ideal. The better way is to enlarge the hole of the central swivel pressing plate and the large pressing plate connected with the machine body, and then use the ZL50 loader to lock it with the transmission shaft bolt and locking gasket

2. The transmission has no high-speed gear

seven of our 13 cranes have experienced the failure of the transmission without high-speed gear. Although no high-speed gear does not affect the slewing operation of the crane, the slow travel can make the transfer time of the crane too long and affect the construction

5. The disassembly and inspection of the transmission system of the electronic tensile testing machine found that the fault was solved by the friction of the high-speed gear: we can add lubricating oil between the gaps to reduce the friction coefficient between them. The main reason is:

there are many aspects that deserve attention (1) artificial damage. When changing from low speed to high speed during driving, directly turn the high-speed and low-speed conversion handle to the high-speed side; However, if you want to switch between high speed and low speed, you must first stop the machine, then change the handle to the low speed position, and keep the high-speed release switch at the release side. And some drivers actually violated this operation requirement, artificially causing damage to the friction plate

(2) the imported friction plate material is too soft, resulting in this fault repeatedly. However, the manufacturer has developed a kind of friction plate with high hard height, and the use effect is very good

(3) fuse failure is frequent. Because the action of the friction plate of the crane is completely controlled by the electrical components, the frequent failure of the fuse leads to the incomplete separation of the friction plate, which accelerates the damage of the friction plate

we solved this problem by training drivers, replacing new friction plates and improving fuses

3. Fuse and fuse socket damage

the plug-in fuse socket used in the original machine is a plastic base. After the plug-in fuse is damaged, we use the domestic plug-in fuse to replace it. However, due to the poor quality of some fuses, there is often the phenomenon that the wheel of the fuse socket is deformed due to overheating, but the fuse is still not fused. Due to its poor contact, the friction plate of the high-speed gear of the transmission is damaged (one of the reasons)

therefore, we have improved the safety device, replaced the original socket with a tubular safety socket, and used a tubular fuse, which has a good effect

4. The hydraulic cylinder of the outrigger leaks oil

13 Ishikawa crane's vertical outrigger cylinders generally began to leak oil after using for 5000 or 6000 hours, especially the three cranes used to install grab

after disassembly and inspection, it was found that the oil leakage was caused by the partial damage of the nylon sealing ring in the outrigger cylinder. The abnormal wear of the seal ring is mainly due to the loosening of the lower locking nut of the outrigger cylinder (not found and tightened in time), which makes the nylon seal ring squeezed and aggravates the wear. During the operation of the crane installing the grab, its main action is that the grab swings towards one side at a high speed and greatly, the load of the outrigger cylinder is much larger than that of the ordinary crane, the locking nut is easier to loosen, the degree of extrusion of the sealing ring is more serious, and the rough operation of some drivers also accelerates the damage of the sealing ring. The nylon sealing ring is very thin. It is difficult to make domestic products. We consulted the Ishikawa island technical service center and learned that the iron ring at the lower part of the vertical outrigger cylinder block should be smashed into a notch and locked to the disassembly port of the locking big nut, so that the big nut can be locked. But when the crane was installed, the manufacturer forgot this, resulting in oil leakage. After replacing the new nylon sealing ring, and according to the user's requirements, grasp the test piece and lock the big nut according to the above method, the problem was indeed solved

5. Hydraulic pump damage

(1) gear pump damage

when the crane works normally, the gear pump and hydraulic oil pipe make a "squeak" sound. When the engine idles, the crane does not rotate. After the oil pressure test, it is preliminarily concluded that the gear pump supplying oil to the rotating parts has been damaged, so that its pressure and flow cannot meet the normal working requirements, resulting in no rotating action. The disassembly and inspection confirmed our judgment that the gear matching clearance of the gear pump is too large. After replacing the new pump, the fault was eliminated (this fault has occurred in 3 of the 13 cranes)

(2) the double piston pump is damaged

the fault phenomenon is that the crane has no lifting and luffing action, and there is a metal impact sound from the double piston pump. It is found that the cylinder block, plunger and slipper of the duplex piston pump have been seriously damaged. After replacing the new pump, the fault was eliminated

6. No backward action

the oil seal of the central rotary cylinder of a crane leaks oil. After replacing the imported parts, the machine is tested, and everything is normal; However, after a few days of shutdown, it was found that other actions were in good condition when it was restarted, but there was no reverse action. After inspection and analysis by many parties, it was preliminarily concluded that the remote control valve of the travel motor was faulty, but it could not be detected, so a good part was removed from other cranes and installed on the test machine, and everything returned to normal. A new remote control valve was replaced, and troubleshooting was completed

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