Reconditioning of parts of precision pairs BOSCH fuel injector with electromagnetic drive

Abstract

Among the details that regulate the reliability of the functioning of the electromagnetic fuel injector, a special place is occupied by its precision pairs, in particular, the sprayer and the control valve, the technical condition of which significantly affects the economic and environmental performance of the engine. In case of failure, BOSCH recommends a factory technology for their repair or replacement, which increases the cost of repair.

The parts of the injector that are destroyed in the first place are the needle, the sprayer body and the control valve seat. Based on the analysis of the type of damage, service centers make decisions on how to return the parameters of the injector to the standard. In particular, if the deterioration in the operation of the injector is caused by the wear of the contact surfaces of the needle and the sprayer body or the control valve seat, then the restoration of these parts is carried out.

In Ukraine, the factory technology of restoring sprayers and control valves of BOSCH injectors is not always sustained because it requires special equipment, therefore, fuel equipment repair stations, each with its own methods, carry out the restoration of branded injectors. The technology of mutual lapping of the needle to the seat of the sprayer body is used, the results of which are poor.

The article proposes a technological process of restoration of working capacity of sprayers and control valves of BOSCH injectors with an electromagnetic drive, which in practice has confirmed its effectiveness. Thus, the restoration of the mating surfaces of the sprayer takes place in two stages: at the first stage, the cone of the sprayer needle is grinded, at the second stage, the surface of the cone of the body is lapped with a special lapping. For this purpose, a complex was developed, which was based on the  special designed and manufactured grinding device. The control valve seat is also restored by the lapping method on the MP-250 universal lapping machine.

The offered technology of restoration of a spray and the control valve of BOSCH fuel injectors allows them to continue their operation without reduction of technical and economic indicators and save money on repairs.