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Mounted crane truck maintenance and repair taboo
The requirements for the use and maintenance of the newly purchased high-quality Mounted crane truck during the running-in period can be summarized as: load reduction, enhanced lubrication, attention to operation, and attention to inspection. However, how to maintain the Mounted crane truck, how to maintain it is correct, and how to maintain it to achieve the function of maintenance, these are huge problems! This article is just a brief experience. But if you can thoroughly understand these understandings. The maintenance related aspects of Mounted crane truck are almost the same.
Mounted crane truck vehicle maintenance is an effective means to restore the performance of special vehicles and extend their service life. However, in the actual operation process, some users and maintenance personnel have many wrong practices, which affect the normal use of special vehicles.
1. Avoid only adding but not changing the oil
Engine oil is indispensable in the use of Mounted crane truck diesel engine, mainly for lubrication, cooling, cleaning, etc. Therefore, many drivers pay attention to checking the amount of lubricating oil and adding it according to the standard, but they neglect the inspection of lubricating oil quality and the replacement of deteriorating oil, resulting in some engine moving parts always in poor lubrication Operation in the environment, thereby accelerating the wear and tear of various parts. Under normal circumstances, the loss of engine oil is not large, but it is easy to pollute, thus losing the role of protecting the diesel engine. During the operation of the diesel engine, a lot of dirt (soot, carbon deposits and fouling, etc., produced by incomplete fuel combustion) will enter the engine oil. For new or overhauled machinery, there will be more impurities after trial operation. If you just add it without replacing it and put it into use in a hurry, it is easy to cause accidents such as tile burning and shaft holding. In addition, even if the engine oil is changed, some drivers will not thoroughly clean the oil passage due to lack of maintenance experience or save trouble, so that mechanical impurities still remain in the oil pan and oil passage.
2. Avoid using butter indiscriminately
Butter is a commonly used grease in the mechanical repair of Mounted crane trucks, which can play a role in lubrication and sealing. Therefore, some repairers will put a layer of butter on the cylinder head gasket when installing the cylinder head gasket, believing that this can increase the sealing performance of the diesel engine. As everyone knows, doing so will affect the working performance of the diesel engine. Cylinder head gasket is the most important seal between the cylinder block and cylinder head of a diesel engine. It can not only seal the high temperature and high pressure gas generated in the cylinder, but also seal the cooling water and lubricating oil in the cylinder head and cylinder block. When installing the cylinder gasket, pay special attention to its sealing quality. If grease is applied to the cylinder head gasket during installation, when the cylinder head bolts are tightened, part of the butter will be squeezed into the cylinder water passage and oil passage. When the butter between the cylinder head gasket is working in the cylinder, part of it will flow due to the influence of high temperature. The human cylinder burns, and the other part remains on the joint surface of the cylinder block and cylinder head, causing gaps between the cylinder head gasket, cylinder head, and the plane of the block. High-temperature and high-pressure gas can easily hit the cylinder head gasket from here, destroying the cylinder head gasket and causing leakage. gas. In addition, the butter will produce carbon deposits when exposed to high temperature for a long time, which will cause premature aging and deterioration of the cylinder head gasket. Therefore, do not apply butter when installing the cylinder head gasket.
3. Avoid inaccurate cylinder clearance measurement
When measuring the cylinder clearance of the Mounted crane truck, it failed to measure in the direction where the piston skirt was perpendicular to the piston pin hole, and measured in other directions. The structure of the aluminum alloy piston is characterized by a small top and a large bottom. It is a cone, and the partial cross-section is elliptical, so the cylinder clearance along the circumferential direction is not equal. When measuring, it is stipulated that the clearance in the direction of the long axis of the ellipse shall prevail, that is, the clearance of the piston skirt perpendicular to the direction of the piston pin hole is measured. This measurement is more convenient and accurate, and in reciprocating motion, the direction of the piston skirt perpendicular to the piston pin hole is greatly worn due to the side pressure. Therefore, when measuring the cylinder gap, the piston skirt should be perpendicular to the piston. The direction of the pin hole is measured.
4. Avoid heating the piston with an open flame
Because Mounted crane truck piston and piston pin have an interference fit, when installing the piston pin, the manufacturer of Mounted crane truck believes that the piston should be heated and expanded first. At this time, some maintenance personnel will directly heat the piston on an open flame. The method is very wrong, because the thickness of each part of the piston is uneven, the degree of thermal expansion and contraction will be different. The heating of an open flame will cause uneven heating of the piston, which is easy to cause deformation; the surface of the piston will also adhere to charcoal, which reduces the use of the piston. life. If the piston cools naturally after reaching a certain temperature, its metallographic structure will be damaged and the wear resistance will be greatly reduced, and its service life will be significantly shortened. When installing the piston pin, the piston can be evenly heated in hot oil to make it expand slowly. Do not use an open flame to heat it directly.
5. Avoid using emery cloth to polish the bearing
For some inexperienced repairers, the bearing bush is a difficult job. Because the scraping technology is difficult to master, the bearing bush is not easy to meet the technical requirements. For this reason, when replacing the bearing bush, it is necessary to increase the bearing bush and crankshaft. Use emery cloth to polish the contact area instead of scraping tiles. This method is extremely undesirable in actual maintenance, because the abrasive grains on the emery cloth are harder, while the bearing alloy is softer, so the sand grains are easily embedded in the alloy during grinding, and the wear of the journal will be accelerated when the diesel engine is working. Shorten the life of the crankshaft.
6. Avoid tightening the bolts too tightly
During the disassembly and assembly process of Mounted crane truck, bolts in many parts have specified torque requirements, such as transmission box, cylinder head, tire, connecting rod and front axle. The tightening torque is specified in the manual. Do not change at will. However, many users mistakenly believe that tightening is safer, but tightening too tight will cause screws or bolts to break, and may also cause malfunctions due to threaded sliding buckles.