SK200-8 维修技术案例分析Maintenance technology case analysis
No.: CKCM-JAL-07-011
Number Category Related Content
Slow motion, insufficient engine output
Model Micro-excavation B92 B93 B94 B128 B130 B132 Other
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Fault phenomenon: The whole machine number: LL11-C5048/LL11-C5014
Working time: 165 hours / 140 hours
Fault phenomenon: 1. The two excavators have a slow operation of the whole machine at almost the same time (one morning, one afternoon).
Among them, the boom movement is the most obvious, and the field test boom rises to 5.69 seconds, which is slower than the standard (2.7-3.3).
It was close to 3 seconds.
2. The engine has a speed drop phenomenon:
· At low speed, the boom rises and the engine speed drops to about 600 rpm. When normal, the speed should rise.
· At high speed, the boom rises and overflows, the engine speed drops by about 50 rpm, and the normal speed should rise.
·Intake pressure high-speed boom overflow is only 170 points, normal should be about 220KPa
·The horsepower decreases when the boom rises (around 60~26)
·Hydraulic and electrical everything else is normal, no bad alarm
Cause Analysis:
Since the two vehicles are not separated from each other for a long time, the following assumptions are made based on this condition:
1. Both cars have a speed difference. Due to the same construction site, the diesel used is the same, and it is speculated that the diesel oil circuit may be faulty.
2. The occurrence of horsepower reduction indicates that the engine output is insufficient. There may be two reasons for this:
First, because there is insufficient intake pressure, it may be because the intake system is faulty, because the engine is on the plateau.
Such a reduction in horsepower appears.
Second, the engine injector/SCV valve is faulty, causing insufficient fuel injection, resulting in insufficient engine output and falling speed.
This possibility is relatively large because the two cars use the same diesel and the oil quality is not good.
Disposal method:
Since the two cars are the same, the 5014 continues to work. Here are the repairs we have made to the 5048:
1. Use the transparent diesel pipeline to check whether the diesel oil circuit has air leakage. The result is that there is no air leakage. Diesel filter before and after the field change, the speed of the speed at the low speed has improved, dropped to more than 700 revolutions, no significant improvement in high speed. During the treatment, the quality of the diesel was found to be very poor. The filter replacement was very bloated in two or three days. The appearance of the diesel oil looked slightly organic and it was sampled for investigation.
2. Check that all intake pipes, turbochargers, and intercoolers are normal, and the failure of the outer space test is still in progress. Determine that the intake air is not faulty.
3. Consult with the product license and discuss with the company to apply for SCV valve and full vehicle injector replacement. First, the SCV valve was taken from the stock car and replaced with the test drive failure. Then the company parts were replaced by the whole vehicle injector test, and the whole vehicle movement returned to normal.
