1. Overhaul of the technical evaluation before
Currently, the project is to restore the machine some more performance overhaul repair of the machine after a longer period of time after the operation, the major components and assemblies of aging have reached the limit, it should all be the disintegration of the machine, cleaning, inspection and repair, achieve its performance standard at the factory.
Construction machinery overhaul is necessary before technical appraisal techniques used by the person in charge of the unit, management, maintenance and driving personnel to participate, the various components of the machine are not pre-dissolution pressure, flow, temperature and torque and other performance testing, and reviewed technical and operational records and other data files, a detailed assessment of the consumption of fuel and lubricants,hoist and trolley and make a detailed record. Then the original information provided by the manufacturer overhaul parameters be compared in order to determine whether repairs are needed.
Determine whether mechanical engineering major overhaul and technical conditions are:
⑴ engine performance indicators fell more than 20%; oil consumption exceeds the fixed value of one times; engine cylinder pressure when the temperature reaches above 45 ℃ when measured less than the required 60% of the index.
⑵ transmission main parts wear reaches the limit level, there is yaw, abnormal noise, shock and jitter phenomena.
⑶ steering worn gap is too large, manipulation failure; transmission gear and shaft wear serious, difficult or often jump shift gear; severely worn brake mechanism, braking performance degradation or failure and can not be adjusted.
(2) repair method of choice
Construction machinery into the plant overhaul,chain block the response to the disintegration of the parts are grouped, measurement, inspection and appraisal, and the assembly of the various components and the engine cylinder, crankshaft, etc. abrasion testing, in order to obtain a basis for whether to replace. Generally wear large moving parts need to be replaced; inconvenience for some replacement parts, should adopt welding, thermal spray, brush plating and chrome and other technology to restore its original design dimensions. Not guarantee the quality, the need to replace parts shall be in accordance with the requirements of the original manufacturer or designated collaborative purchase of spare parts manufacturers.
Repair method is divided into: repair and replacement assembly for motor repairs. The car repair method, that is, during the repair parts are sequentially removed from the machine, after washing, detection, classification, and repair or replacement, and finally reassembled in order to achieve the recovery performance of the repair methods. Law on car repair repair downtime longer occupied.
Replace assembly repair method, is in the repair process, in addition to the original rack renovations, the only remaining assembly is damaged or accessories all removed, replaced with pre-prepared (or repair) good assembly or accessories , and then assembled into machine repair methods. This method can significantly reduce downtime repair time, help to improve repairman efficiency, reduce costs and ensure the quality of maintenance. This is also the most popular American maintenance system maintenance methods, which increase the use of machinery and equipment intact rate units, utilization and production efficiency of great significance.
⑴ taken to exclude security risks. Overhaul process should be taken to exclude security risks, such as: adjusting brake clearance, replace worn clutch friction plate and the cab seat can be easily adjusted up or down, and the removal of some of the drivers and maintenance personnel likely to cause injury and machine failure security risks. Enhance driver awareness of labor protection, making the machine dangerous experiments, sufficient space should be left around and protective facilities (such as: electric
wire rope hoist maximum load operation during the experiment wounding accident prone disintegration).
⑵ do overhauled tracking service. Build construction machinery overhaul maintenance files, and the unit should be repaired within a certain period after repair works to ensure mechanical energy to achieve the specified performance and good condition. During this period, such as general failure occurred, after adjustment to get rid of those who should be using the units themselves. Eg due to larger changes. Mechanical damage, severe oil spills, leaks, leakage and leakage and other major components must be disassembled for repair, the unit should be serviced by a joint notification repair unit inspection, timely repair to reduce downtime,manual hoist so after Overhaul the machine can be kept in good working condition.