I. Overview
In the fuel pump maintenance process, the most frequent and most important test equipment is the fuel pump test bench. The fuel injection pump test bench, the most influential factor is its fuel base - standard injector assembly. The average fuel gauge unevenness of a standard fuel injector assembly affects not only the "scale" accuracy of a fuel injection pump test bed, but also the performance of the fuel pump being debugged. Therefore, the standard fuel injector assembly in the fuel pump repair debugging process plays a very important role.
Standard fuel injector assembly Xu Xu in the manufacturing process to meet the current industry standards, the group used when the flow of what kind of reference to the actual use of the pump will have any impact on this article to explore and highlight in this regard Application of Type A Flow Reference Pump in Maintenance and Adjustment of Pump.
Two-cylinder B-type pump and A-type flow reference pump
Two-cylinder B-type BH2B90 that is standard fuel injection pump, the plunger diameter of 9mm. The technical requirements of the standard pump states that "when the standard injection pump speed 1000r / min, with the standard test fuel injector assembly test, the fixed gear position for the oil supply 101mm3 / cycle." Because of the characteristics of the standard pump, when the speed exceeds 1150r / min, the inertia force has exceeded the elastic force of the plunger spring, causing the cam and the plunger to disengage, so that the oil on the abnormal phenomenon occurs, so the use of two cylinders B standard pump into a group of standard injector assembly applies only to adjust the calibration speed of 1000r / min below the fuel pump.
Type A flow reference pumps are carefully selected and commissioned Type A pumps (four-cylinder or six-cylinder) with governor, advancer and fuel pump with plunger diameters ≥ 9 mm. When the standard injector A type flow reference pump for group test, the speed up to 1450r / min or more.
In order to understand the difference between the two-cylinder B-type pump and the A-type flow-rate reference pump on the standard injector assembly, we conducted the following tests:
First, the use of two-cylinder B-type pump reference cylinder at 1000r / min, the group B group of twelve standard injector assembly, the test data shown in Table 1; then Group B twelve standard injector total Into the A-type flow reference pump reference cylinder, at 1450r / min speed test data obtained in Table 2. Second, the use of A-type flow reference pump reference cylinder at 1450r / min, a group of twelve standard injector assembly, the test data shown in Table 3; then A group of twelve standard injector total Into the B-type pump on the reference cylinder to 1000r / min speed test data, see Table 4. Finally, analyzing these test data, it can be seen that the standard fuel injector using a two-cylinder B-type standard pump is significantly out of tolerance when tested on a Type A flow-rate reference pump, whereas Type A Flow standard pump into a group of standard injectors in the two-cylinder B-type pump test average oil unevenness can still be a good guarantee.
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Three standard pump maintenance of fuel injector features
At present, the service points of oil pump are all over the country, and its repairs are in the fields of automobile, construction machinery, power generation, marine and so on, while the main ones are automobile and engineering machinery. The vast majority of fuel injection pumps involved are Type A pumps and No. 1 pumps. It is well-known that both Type A and Type I pumps have a nominal speed of more than 1000 rpm and therefore it is not appropriate to use a standard two-cylinder B-type pump assembly, which is grouped with Type A flow- Standard injector assembly is the most suitable.
Four A-type flow reference pump use
Type A flow reference pump is mainly used in the following two aspects:
1. Manufacturers of standard fuel injector assemblies
In order to create a standard fuel injector assembly that is suitable for fuel pump service, a manufacturer of standard fuel injector assemblies must use Type A flow reference pumps to test a standard set of fuel injectors.
2. Pump maintenance points
As China still lacks the necessary oil base transfer system, the repair points are relatively dispersed, and the standard fuel injector assembly debugging in the pump is so important, so the pump maintenance point with a type A flow reference pump is very Necessary, its advantages are as follows:
a) To be able to check the standard fuel injector test bench at any time, to determine its correctness, repair a matter of course.
b) Once the standard injector found a problem, can be resolved in time, such as the replacement of the standard injector filter, nozzle replacement parts, etc., save time and solve the problem intuitive.
c) Unnecessary misgivings and errors such as governor adjustments during fuel pump commissioning are eliminated due to the correctness of the standard injectors.
d) Increased standard injector life. With the ability to calibrate your own standard injectors at any time, the probability of blind replacement or scrap is reduced.
There is a pump nozzle repair station repair a car with a diesel pump A-type pump, the meticulous disassembly, cleaning and debugging and found that the car or fuel consumption, lack of horsepower, and then find out the reason for some reason. After the reference flow pump calibration test bench standard injector assembly and found that large deviation of oil deviation, re-adjust the commissioning, the car is working properly.
Five conclusions
1. Two-cylinder B-pump standard pump used in the fuel pump maintenance unit calibration standard injector assembly is not appropriate.
2. Fuel pump maintenance units use type A flow reference pump, which can check the precision of the standard fuel injector assembly in time in order to properly debug the performance of fuel injection pump.
