The spider cranes produced by Zhengzhou Kebu Technology Co., Ltd. have played an important role in the construction of bridges and roads, building greening, State Grid power stations, factory workshops and other scenes. And we all know that regular maintenance of spider cranes is an essential step in the use of this equipment. The purpose of doing so is to restore its performance and prolong its service life to a large extent. However, in this process, some maintenance personnel will also have wrong practices, which will affect its normal use. Therefore, the following are the misunderstandings in the maintenance of this equipment.
NO.1
Avoid installing new cylinder liner and piston without matching
When replacing the cylinder liner and piston, the repairman believed that the new cylinder liner and piston were standard and interchangeable. In fact, the dimensions of the cylinder liner and the piston have a certain tolerance range. If a large-sized cylinder liner is matched with a small-sized piston, it will cause excessive clearance, weak compression, and difficulty in starting.
NO.2
Avoid messing with butter
(1) Grease the cylinder head gasket. Butter is a commonly used grease in the repair of small cranes, which can play the role of lubrication and sealing. Some repairmen also apply a layer of butter when installing the cylinder head gasket, mistakenly thinking that this can increase the sealing performance of the diesel engine. However, this affects the performance of the diesel engine.
(2) Butter the tire nuts. After the tire nut is tightened, the threads have a self-locking feature. This is because the thread helix angle is smaller than the equivalent friction angle between threads. In a given bolted connection, the helix angle is a certain value, and the equivalent friction angle varies with the friction state between the threads. Many repairmen apply oil to the bolts and nuts of the tires, which reduces the equivalent friction angle between the threads and deteriorates the self-locking performance of the bolted connection. Therefore, be careful not to apply grease or drip oil on the bolts and nuts of small crane tires.
NO.3
Check the plunger stroke allowance
During the debugging of the plunger fuel injection pump, many maintenance personnel do not pay attention to checking the stroke margin of the plunger. The so-called stroke margin of the plunger refers to the amount of movement that the plunger can continue to move upward after the plunger is pushed to the top dead center by the cam on the camshaft. After adjusting the oil supply start time, the reason for checking the stroke allowance is that the stroke allowance of the plunger is related to the wear of the plunger and the sleeve. After the plunger and the sleeve are worn out, the plunger has to move up for a while before the oil supply can start, so that the oil supply start time is delayed.