Restoration of control valve parts BOSCH fuel injector with piezoelectric actuator

Abstract

The parameters of a piezoelectric fuel injector depend on 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 of these precision pairs, BOSCH recommends replacing the whole injector, which increases the cost of repair.

Operational practice shows that in the first place the control valve and the atomizer's needle and body are destroyed. Based on the analysis of the type of damage, the service centers decide 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, then the restoration of these parts is carried out.

Instead, the technology of restoring sprayers and control valves of BOSCH injectors does not always correspond to the factory, as it requires special equipment, so fuel equipment repair stations, each with its methods, restore branded injectors. Usually, the process of mutual grinding of the valve stem to the seat is used, which can, in turn, disable the injector.

 The article proposes the technology of restoring the operation of the BOSCH fuel injector control valve with a piezoelectric actuator, which has proved its effectiveness in practice. The process of restoring the conjugate surfaces of the control valve takes place in stages. At the first stage, both cones of the valve stem are reground. For this purpose, a complex was developed, the basis of which was a specially designed and manufactured device for regrinding. In the second stage, the surface of the valve seat is restored by lapping on a universal lapping machine MR-250. The final stage is the grinding of the surface of the valve seat to the throttle plate.

The proposed technology for restoring the control valve of BOSCH fuel injectors with piezoelectric drive allows you to continue their operation while maintaining technical and economic performance and saving money on the repair.

Keywords: BOSCH piezoelectric injector, control valve, valve stem and seat, conjugate surfaces, restoring technology